header advert
Results 1 - 100 of 783
Results per page:
The Bone & Joint Journal
Vol. 104-B, Issue 2 | Pages 221 - 226
1 Feb 2022
Edwards NM Varnum C Nelissen RGHH Overgaard S Pedersen AB

Aims. The aim of this study was to examine whether socioeconomic status (SES) is associated with a higher risk of infections following total hip arthroplasty (THA) at 30 and 90 days. Methods. We obtained individual-based information on SES markers (cohabitation, education, income, and savings) on 103,901 THA patients from Danish health registries between 1 January 1995 and 31 December 2017. The primary outcome measure was any hospital-treated infection (i.e. all infections). The secondary outcomes were further specified to specific hospital-treated infections (pneumonia, urinary tract infection, and periprosthetic joint infection). The primary timepoint was within 90 days. In addition, the outcomes were further evaluated within 30 days. We calculated the cumulative incidence, and used the pseudo-observation method and generalized linear regression to estimate adjusted risk ratios (RRs) with 95% confidence intervals (CIs) for each marker. Results. The cumulative incidence of any infection at 90 days was highest in patients who lived alone (1.5% (95% CI 1.3 to 1.6)) versus cohabitant (0.7% (95% CI 0.7 to 0.8)), had the lowest educational achievement (1.1% (95% CI 1.0 to 1.2)) versus highest (0.7% (95% CI 0.5 to 0.8)), had the lowest income (1.6% (95% CI 1.5 to 1.70)) versus highest (0.4% (95% CI 0.3 to 0.5)), or had lowest savings (1.3% (95% CI 1.2 to 1.4)) versus highest (0.7% (95% CI 0.6 to 0.8)). Within 90 days, the RRs for any infection were 1.3 (95% CI 1.2 to 1.4) for patients living alone versus cohabiting, 1.2 (95% CI 1.0 to 1.3) for low education achievement versus high, 1.7 (95% CI 1.4 to 2.1) for low income versus high income, and 1.5 (95% CI 1.4 to 1.8) for low savings versus high savings. The same trends were also seen for any infections within the first 30 days. Conclusion. Our study provides evidence that socioeconomic inequality adversely influences the risk of infection after THA, thus contributing to healthcare disparities and inequalities. We found that living alone, low educational achievement, low income, or low savings were associated with higher risks of infections within the first 30 and 90 days after THA. Therefore, the development of targeted intervention strategies with the aim of increasing awareness of patients identified as being at greatest risk is needed to mitigate the impact of SES on the risk of infections following THA. Cite this article: Bone Joint J 2022;104-B(2):221–226


The Bone & Joint Journal
Vol. 104-B, Issue 10 | Pages 1168 - 1173
1 Oct 2022
Gazendam AM Schneider P Vélez R Ghert M

Aims. The aim of this study was to determine the prevalence and impact of tourniquet use in patients undergoing limb salvage surgery with endoprosthetic reconstruction for a tumour around the knee. Methods. We retrieved data from the Prophylactic Antibiotic Regimens in Tumor Surgery (PARITY) trial; specifically, differences in baseline characteristics, surgical details, and postoperative functional outcomes between patients who had undergone surgery under tourniquet and those who had not. A linear regression model was created to evaluate the impact of tourniquet use on postoperative Toronto Extremity Salvage Scores (TESSs) while controlling for confounding variables. A negative-binomial regression model was constructed to explore predictors of postoperative length of stay (LOS). Results. Of the 604 patients enrolled in the PARITY trial, 421 had tumours around the knee joint, of whom 225 (53%) underwent surgery under tourniquet. The tourniquet group was younger (p = 0.014), more likely to undergo surgery for a tumour of the tibia, and had shorter operating times by a mean of 50 minutes (95% confidence interval 30 to 72; p < 0.001). The adjusted linear regression model found that the use of a tourniquet, a shorter operating time, and a higher baseline TESS independently predicted better function at both three- and six-month follow-up. The negative-binomial regression model showed that tourniquet use, shorter operating time, younger age, and intraoperative tranexamic acid administration independently predicted a shorter LOS in hospital. Conclusion. The results of this study show that in patients undergoing resection of a tumour around the knee and endoprosthetic reconstruction, the use of an intraoperative tourniquet is associated with a shorter operating time, a reduced length of stay in hospital, and a better early functional outcome. Cite this article: Bone Joint J 2022;104-B(10):1168–1173


Bone & Joint Open
Vol. 2, Issue 12 | Pages 1057 - 1061
1 Dec 2021
Ahmad SS Weinrich L Giebel GM Beyer MR Stöckle U Konrads C

Aims. The aim of this study was to determine the association between knee alignment and the vertical orientation of the femoral neck in relation to the floor. This could be clinically important because changes of femoral neck orientation might alter chondral joint contact zones and joint reaction forces, potentially inducing problems like pain in pre-existing chondral degeneration. Further, the femoral neck orientation influences the ischiofemoral space and a small ischiofemoral distance can lead to impingement. We hypothesized that a valgus knee alignment is associated with a more vertical orientation of the femoral neck in standing position, compared to a varus knee. We further hypothesized that realignment surgery around the knee alters the vertical orientation of the femoral neck. Methods. Long-leg standing radiographs of patients undergoing realignment surgery around the knee were used. The hip-knee-ankle angle (HKA) and the vertical orientation of the femoral neck in relation to the floor were measured, prior to surgery and after osteotomy-site-union. Linear regression was performed to determine the influence of knee alignment on the vertical orientation of the femoral neck. Results. The cohort included 147 patients who underwent knee realignment-surgery. The mean age was 51.5 years (SD 11). Overall, 106 patients underwent a valgisation-osteotomy, while 41 underwent varisation osteotomy. There was a significant association between the orientation of the knee and the coronal neck-orientation. In the varus group, the median orientation of the femoral neck was 46.5° (interquartile range (IQR) 49.7° to 50.0°), while in the valgus group, the orientation was 52.0° (IQR 46.5° to 56.7°; p < 0.001). Linear regression analysis revealed that HKA demonstrated a direct influence on the coronal neck-orientation (β = 0.5 (95% confidence interval (CI) 0.2 to 0.7); p = 0.002). Linear regression also showed that realignment surgery was associated with a significant influence on the change in the coronal femoral neck orientation (β = 5.6 (95% CI 1.5 to 9.8); p = 0.008). Conclusion. Varus or valgus knee alignment is associated with either a more horizontal or a more vertical femoral neck orientation in standing position, respectively. Subsequently, osteotomies around the knee alter the vertical orientation of the femoral neck. These aspects are of importance when planning osteotomies around the knee in order to appreciate the effects on the adjacent hip joint. The concept may be of even more relevance in dysplastic hips. Cite this article: Bone Jt Open 2021;2(12):1057–1061


Bone & Joint Open
Vol. 3, Issue 1 | Pages 12 - 19
3 Jan 2022
Salih S Grammatopoulos G Burns S Hall-Craggs M Witt J

Aims. The lateral centre-edge angle (LCEA) is a plain radiological measure of superolateral cover of the femoral head. This study aims to establish the correlation between 2D radiological and 3D CT measurements of acetabular morphology, and to describe the relationship between LCEA and femoral head cover (FHC). Methods. This retrospective study included 353 periacetabular osteotomies (PAOs) performed between January 2014 and December 2017. Overall, 97 hips in 75 patients had 3D analysis by Clinical Graphics, giving measurements for LCEA, acetabular index (AI), and FHC. Roentgenographical LCEA, AI, posterior wall index (PWI), and anterior wall index (AWI) were measured from supine AP pelvis radiographs. The correlation between CT and roentgenographical measurements was calculated. Sequential multiple linear regression was performed to determine the relationship between roentgenographical measurements and CT FHC. Results. CT-measured LCEA and AI correlated strongly with roentgenographical LCEA (r = 0.92; p < 0.001) and AI (r = 0.83; p < 0.001). Radiological LCEA correlated very strongly with CT FHC (r = 0.92; p < 0.001). The sum of AWI and PWI also correlated strongly with CTFHC (r = 0.73; p < 0.001). CT measurements of LCEA and AI were 3.4° less and 2.3° greater than radiological LCEA and AI measures. There was a linear relation between radiological LCEA and CT FHC. The linear regression model statistically significantly predicted FHC from LCEA, F(1,96) = 545.1 (p < 0.001), adjusted R. 2. = 85.0%, with the prediction equation: CT FHC(%) = 42.1 + 0.77(XRLCEA). Conclusion. CT and roentgenographical measurement of acetabular parameters are comparable. Currently, a radiological LCEA greater than 25° is considered normal. This study demonstrates that those with hip pain and normal radiological acetabular parameters may still have deficiencies in FHC. More sophisticated imaging techniques such as 3D CT should be considered for those with hip pain to identify deficiencies in FHC. Cite this article: Bone Jt Open 2022;3(1):12–19


The Bone & Joint Journal
Vol. 104-B, Issue 6 | Pages 687 - 695
1 Jun 2022
Sabah SA Knight R Alvand A Beard DJ Price AJ

Aims. Routinely collected patient-reported outcome measures (PROMs) have been useful to quantify and quality-assess provision of total hip arthroplasty (THA) and total knee arthroplasty (TKA) in the UK for the past decade. This study aimed to explore whether the outcome following primary THA and TKA had improved over the past seven years. Methods. Secondary data analysis of 277,430 primary THAs and 308,007 primary TKAs from the NHS PROMs programme was undertaken. Outcome measures were: postoperative Oxford Hip/Knee Score (OHS/OKS); proportion of patients achieving a clinically important improvement in joint function (responders); quality of life; patient satisfaction; perceived success; and complication rates. Outcome measures were compared based on year of surgery using multiple linear and logistic regression models. Results. For primary THA, multiple linear regression modelling found that more recent year of surgery was associated with higher postoperative OHS (unstandardized coefficient (B) 0.15 points (95% confidence interval (CI) 0.14 to 0.17); p < 0.001) and higher EuroQol five-dimension index (EQ-5D) utility (B 0.002 (95% CI 0.001 to 0.002); p < 0.001). The odds of being a responder (odds ratio (OR) 1.02 (95% CI 1.02 to 1.03); p < 0.001) and patient satisfaction (OR 1.02 (95% CI 1.01 to 1.03); p < 0.001) increased with year of surgery, while the odds of any complication reduced (OR 0.97 (95% CI 0.97 to 0.98); p < 0.001). No trend was found for perceived success (p = 0.555). For primary TKA, multiple linear regression modelling found that more recent year of surgery was associated with higher postoperative OKS (B 0.21 points (95% CI 0.19 to 0.22); p < 0.001) and higher EQ-5D utility (B 0.002 (95% CI 0.002 to 0.003); p < 0.001). The odds of being a responder (OR 1.04 (95% CI 1.03 to 1.04); p < 0.001), perceived success (OR 1.02 (95% CI 1.01 to 1.02); p < 0.001), and patient satisfaction (OR 1.02 (95% CI 1.01 to 1.02); p < 0.001) all increased with year of surgery, while the odds of any complication reduced (OR 0.97 (95% CI 0.97 to 0.97); p < 0.001). Conclusion. Nearly all patient-reported outcomes following primary THA/TKA improved by a small amount over the past seven years. Due to the high proportion of patients achieving good outcomes, PROMs following THA and TKA may need to focus on better discrimination of patients achieving high scores to be able to continue to measure improvement in outcomes. Cite this article: Bone Joint J 2022;104-B(6):687–695


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_3 | Pages 115 - 115
23 Feb 2023
Chai Y Boudali A Farey J Walter W
Full Access

Pelvic tilt (PT) is always described as the pelvic orientation along the transverse axis, yet four PT definitions were established based on different radiographic landmarks: anterior pelvic plane (PT. a. ), the centres of femoral heads and sacral plate (PT. m. ), pelvic outlet (PT. h. ), and sacral slope (SS). These landmarks quantify a similar concept, yet understanding of their relationships is lacking. Some studies referred to the words “pelvic tilt” for horizontal comparisons, but their PT definitions might differ. There is a demand for understanding their correlations and differences for education and research purposes. This study recruited 105 sagittal pelvic radiographs (68 males and 37 females) from a single clinic awaiting their hip surgeries. Hip hardware and spine pathologies were examined for sub-group analysis. Two observers annotated four PTs in a gender-dependent manner and repeated it after six months. The linear regression model and intraclass correlation coefficient (ICC) were applied with a 95% significance interval. The SS showed significant gender differences and the lowest correlations to the other parameters in the male group (-0.3< r <0.2). The correlations of SS in scoliosis (n = 7) and hip implant (female, n = 18) groups were statistically different, yet the sample sizes were too small. PT. m. demonstrated very strong correlation to PT. h. (r > 0.9) under the linear model PT. m. = 0.951 × PT. h. - 68.284. The PT. m. and PT. h. are interchangeable under a simple linear regression model, which enables study comparisons between them. In the male group, SS is more of a personalised spinal landmark independent of the pelvic anatomy. Female patients with hip implant may have more static spinopelvic relationships following a certain pattern, yet a deeper study using a larger dataset is required. The understanding of different PTs improves anatomical education


The Bone & Joint Journal
Vol. 102-B, Issue 6 Supple A | Pages 85 - 90
1 Jun 2020
Blevins JL Rao V Chiu Y Lyman S Westrich GH

Aims. The purpose of this investigation was to determine the relationship between height, weight, and sex with implant size in total knee arthroplasty (TKA) using a multivariate linear regression model and a Bayesian model. Methods. A retrospective review of an institutional registry was performed of primary TKAs performed between January 2005 and December 2016. Patient demographics including patient age, sex, height, weight, and body mass index (BMI) were obtained from registry and medical record review. In total, 8,100 primary TKAs were included. The mean age was 67.3 years (SD 9.5) with a mean BMI of 30.4 kg/m. 2. (SD 6.3). The TKAs were randomly split into a training cohort (n = 4,022) and a testing cohort (n = 4,078). A multivariate linear regression model was created on the training cohort and then applied to the testing cohort . A Bayesian model was created based on the frequencies of implant sizes in the training cohort. The model was then applied to the testing cohort to determine the accuracy of the model at 1%, 5%, and 10% tolerance of inaccuracy. Results. Height had a relatively strong correlation with implant size (femoral component anteroposterior (AP) Pearson correlation coefficient (ρ) = 0.73, p < 0.001; tibial component mediolateral (ML) ρ = 0.77, p < 0.001). Weight had a moderately strong correlation with implant size, (femoral component AP ρ = 0.46, p < 0.001; tibial ML ρ = 0.48, p < 0.001). There was a significant linear correlation with height, weight, and sex with implant size (femoral component R. 2. = 0.607, p < 0.001; tibial R. 2. = 0.695, p < 0.001). The Bayesian model showed high accuracy in predicting the range of required implant sizes (94.4% for the femur and 96.6% for the tibia) accepting a 5% risk of inaccuracy. Conclusion. Implant size was correlated with basic demographic variables including height, weight, and sex. The linear regression and Bayesian models accurately predicted required implant sizes across multiple manufacturers based on height, weight, and sex alone. These types of predictive models may help improve operating room and implant supply chain efficiency. Level of Evidence: Level IV. Cite this article: Bone Joint J 2020;102-B(6 Supple A):85–90


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_12 | Pages 16 - 16
10 Jun 2024
Azam M Colasanti C Butler J Weiss M Brodeur P Kennedy J
Full Access

Introduction. The purpose of this study was to examine trends in patient characteristics and clinical outcomes that occur with age as a statistical variable when performing autologous osteochondral transplantation (AOT) for the treatment of osteochondral lesions of the talus (OLT). Methods. A retrospective cohort study for AOT procedures on 78 patients from 2006 to 2019. was conducted Clinical outcomes were evaluated via FAOS scores. A multivariable linear regression was used to assess the independent factors predictive of the first post-operative FAOS after AOT. The independent variables included pre-operative FAOS, age, defect size, shoulder lesion, cystic lesion, prior traumatic injury, and history of microfracture surgery. A p-value <.05 was considered significant and 95% confidence limits (95% CL) for regression coefficient estimates (est.) were calculated. Results. 78 patients were included with a mean age of 35.5 ± 13.6years at a mean follow-up was 54.4 ± 18.9 months. The mean pre-operative FAOS was 54.3 ± 19.4 and the mean post-operative FAOS was 83.4 ± 13.6. The mean defect size was 109.3±62.4 mm2. The multivariable linear regression showed that the pre-operative FAOS was associated with a higher post-operative FAOS (est., 95% CL: 0.16, 0.012 – 0.307; p=0.034). Defect size (est., 95% CL: −0.05, −0.097 – −0.003; p=0.0358), having a shoulder lesion (est., 95% CL: −9.068, −15.448 – −2.688; p=0.006), or having a prior microfracture surgery (est., 95% CL: −7.07, −13.118 – −1.021; p=0.0226) were associated with a lower post-operative FAOS. Conclusion. Patient age was not an independent risk factor for inferior clinical outcomes after AOT for OLT. Additionally, cystic lesions, or lesions with a traumatic aetiology were not significantly associated with post-operative FAOS. Having a shoulder lesion had the largest marginal effect on post-operative FAOS. These findings provide important information for providers when counseling and selecting patients for AOT procedure for treatment of OLT


Total hip arthroplasty has been constantly evolving with technological improvements to achieve the best survival rates. Although the new implants are under closer surveillance through processes such as Beyond Compliance, orthopaedic surgeons generally tend to look out for the latest implants with good short-term results and hope for better long-term results for these. We questioned whether such an assumption or bias is valid. We analysed the data of Kaplan-Meier estimates of cumulative revisions of primary hip replacement by fixation, stem/cup brand and bearing combinations from the NJR 19th Annual Report published in September 2022. We performed a univariate linear regression analysis to predict the 10- and 15-year revision rates for these different hip implant combinations from the 3- and 5-year revision rates. Thirty-seven implant combinations had their 15-year revision rates reported and 67 had the 10-year revision rates. The correlation co-efficients were 0.43 and 0.58 for the 3-year and 5-year revision rates against 15-year revision rates. Only 17% of the variance in 15-year revision rates could be predicted by a linear regression model from the 3-year revision rate and 32% from the 5-year revision rate. Corresponding values for the 10-year revision rates were 46% and 67%. 95% prediction intervals for the 15-year revision rate were +/− 3.1% from the 3-year revision rate and +/− 2.8% from the 5-year revision rate. Corresponding values for the 10-year revision rates were +/− 1.3% and +/− 1%. 19 of 37 implant combinations showed 15-year revision rate of more than 4%. Average 3-year and 5-year revision rates for this cohort was 1.0% and 1.42% compared to 1.4% and 1.9% for the rest and the difference was statistically significant. Although average early revision rates showed small but significant difference between the groups with lower and higher 15-year revision rates, the prediction intervals for 15-year revision rates for individual hips based on their 3-year and 5-year revision rates are very wide. Three- and 5-year revision rates for primary total hip replacements are poor predictors of 15-year revision rates


Bone & Joint Open
Vol. 3, Issue 10 | Pages 841 - 849
27 Oct 2022
Knight R Keene DJ Dutton SJ Handley R Willett K

Aims. The rationale for exacting restoration of skeletal anatomy after unstable ankle fracture is to improve outcomes by reducing complications from malunion; however, current definitions of malunion lack confirmatory clinical evidence. Methods. Radiological (absolute radiological measurements aided by computer software) and clinical (clinical interpretation of radiographs) definitions of malunion were compared within the Ankle Injury Management (AIM) trial cohort, including people aged ≥ 60 years with an unstable ankle fracture. Linear regressions were used to explore the relationship between radiological malunion (RM) at six months and changes in function at three years. Function was assessed with the Olerud-Molander Ankle Score (OMAS), with a minimal clinically important difference set as six points, as per the AIM trial. Piecewise linear models were used to investigate new radiological thresholds which better explain symptom impact on ankle function. Results. Previously described measures of RM and surgeon opinion of clinically significant malunion (CSM) were shown to be related but with important differences. CSM was more strongly related to outcome (-13.9 points on the OMAS; 95% confidence interval (CI) -21.9 to -5.4) than RM (-5.5 points; 95% CI -9.8 to -1.2). Existing malunion thresholds for talar tilt and tibiofibular clear space were shown to be slightly conservative; new thresholds which better explain function were identified (talar tilt > 2.4°; tibiofibular clear space > 6 mm). Based on this new definition the presence of RM had an impact on function, which was statistically significant, but the clinical significance was uncertain (-9.1 points; 95% CI -13.8 to -4.4). In subsequent analysis, RM of a posterior malleolar fracture was shown to have a statistically significant impact on OMAS change scores, but the clinical significance was uncertain (-11.6 points; 95% CI -21.9 to -0.6). Conclusion. These results provide clinical evidence which supports the previously accepted definitions. Further research to investigate more conservative clinical thresholds for malunion is indicated. Cite this article: Bone Jt Open 2022;3(10):841–849


Bone & Joint Open
Vol. 5, Issue 1 | Pages 3 - 8
2 Jan 2024
Husum H Hellfritzsch MB Maimburg RD Møller-Madsen B Henriksen M Lapitskaya N Kold S Rahbek O

Aims. The present study seeks to investigate the correlation of pubofemoral distances (PFD) to α angles, and hip displaceability status, defined as femoral head coverage (FHC) or FHC during manual provocation of the newborn hip < 50%. Methods. We retrospectively included all newborns referred for ultrasound screening at our institution based on primary risk factor, clinical, and PFD screening. α angles, PFD, FHC, and FHC at follow-up ultrasound for referred newborns were measured and compared using scatter plots, linear regression, paired t-test, and box-plots. Results. We included 2,735 newborns, of whom 754 received a follow-up hip ultrasound within six weeks of age. After exclusion, 1,500 hips were included for analysis. Sex distribution was 372 male and 380 female, and the mean age at examination was 36.6 days (4 to 87). We found a negative linear correlation of PFD to α angles (p < 0.001), FHC (p < 0.001), and FHC during provocation (p < 0.001) with a 1 mm increase in PFD corresponding to a -2.1° (95% confidence interval (CI) -2.3 to -1.9) change in α angle and a -3.4% (95% CI -3.7 to -3.0) change in FHC and a -6.0% (-6.6 to -5.5) change in FHC during provocation. The PFD was significantly higher with increasing Graf types and in displaceable hips (p < 0.001). Conclusion. PFD is strongly correlated to both α angles and hip displaceability, as measured by FHC and FHC during provocation, in ultrasound of newborn hips. The PFD increases as the hips become more dysplastic and/or displaceable. Cite this article: Bone Jt Open 2023;5(1):3–8


The Bone & Joint Journal
Vol. 104-B, Issue 9 | Pages 1025 - 1031
1 Sep 2022
Thummala AR Xi Y Middleton E Kohli A Chhabra A Wells J

Aims. Pelvic tilt is believed to affect the symptomology of osteoarthritis (OA) of the hip by alterations in joint movement, dysplasia of the hip by modification of acetabular cover, and femoroacetabular impingement by influencing the impingement-free range of motion. While the apparent role of pelvic tilt in hip pathology has been reported, the exact effects of many forms of treatment on pelvic tilt are unknown. The primary aim of this study was to investigate the effects of surgery on pelvic tilt in these three groups of patients. Methods. The demographic, radiological, and outcome data for all patients operated on by the senior author between October 2016 and January 2020 were identified from a prospective registry, and all those who underwent surgery with a primary diagnosis of OA, dysplasia, or femoroacetabular impingement were considered for inclusion. Pelvic tilt was assessed on anteroposterior (AP) standing radiographs using the pre- and postoperative pubic symphysis to sacroiliac joint (PS-SI) distance, and the outcomes were assessed with the Hip Outcome Score (HOS), International Hip Outcome Tool (iHOT-12), and Harris Hip Score (HHS). Results. The linear regression model revealed a significant negative predictive association between the standing pre- and postoperative PS-SI distances for all three groups of patients (all p < 0.001). There was a significant improvement in all three outcome measures between the pre- and postoperative values (p < 0.05). Conclusion. There is a statistically significant decrease in pelvic tilt after surgery in patients with OA of the hip, dysplasia, and femoroacetabular impingement. These results confirm that surgery significantly alters the pelvic orientation. Pelvic tilt significantly decreased after total hip arthroplasty, periacetabular osteotomy, and arthroscopy/surgical hip dislocation. The impact of surgery on pelvic tilt should be considered within the therapeutic plan in order to optimize pelvic orientation in these patients. Cite this article: Bone Joint J 2022;104-B(9):1025–1031


Bone & Joint Research
Vol. 12, Issue 5 | Pages 313 - 320
8 May 2023
Saiki Y Kabata T Ojima T Kajino Y Kubo N Tsuchiya H

Aims. We aimed to assess the reliability and validity of OpenPose, a posture estimation algorithm, for measurement of knee range of motion after total knee arthroplasty (TKA), in comparison to radiography and goniometry. Methods. In this prospective observational study, we analyzed 35 primary TKAs (24 patients) for knee osteoarthritis. We measured the knee angles in flexion and extension using OpenPose, radiography, and goniometry. We assessed the test-retest reliability of each method using intraclass correlation coefficient (1,1). We evaluated the ability to estimate other measurement values from the OpenPose value using linear regression analysis. We used intraclass correlation coefficients (2,1) and Bland–Altman analyses to evaluate the agreement and error between radiography and the other measurements. Results. OpenPose had excellent test-retest reliability (intraclass correlation coefficient (1,1) = 1.000). The R. 2. of all regression models indicated large correlations (0.747 to 0.927). In the flexion position, the intraclass correlation coefficients (2,1) of OpenPose indicated excellent agreement (0.953) with radiography. In the extension position, the intraclass correlation coefficients (2,1) indicated good agreement of OpenPose and radiography (0.815) and moderate agreement of goniometry with radiography (0.593). OpenPose had no systematic error in the flexion position, and a 2.3° fixed error in the extension position, compared to radiography. Conclusion. OpenPose is a reliable and valid tool for measuring flexion and extension positions after TKA. It has better accuracy than goniometry, especially in the extension position. Accurate measurement values can be obtained with low error, high reproducibility, and no contact, independent of the examiner’s skills. Cite this article: Bone Joint Res 2023;12(5):313–320


Bone & Joint Open
Vol. 3, Issue 7 | Pages 573 - 581
1 Jul 2022
Clement ND Afzal I Peacock CJH MacDonald D Macpherson GJ Patton JT Asopa V Sochart DH Kader DF

Aims. The aims of this study were to assess mapping models to predict the three-level version of EuroQoL five-dimension utility index (EQ-5D-3L) from the Oxford Knee Score (OKS) and validate these before and after total knee arthroplasty (TKA). Methods. A retrospective cohort of 5,857 patients was used to create the prediction models, and a second cohort of 721 patients from a different centre was used to validate the models, all of whom underwent TKA. Patient characteristics, BMI, OKS, and EQ-5D-3L were collected preoperatively and one year postoperatively. Generalized linear regression was used to formulate the prediction models. Results. There were significant correlations between the OKS and EQ-5D-3L preoperatively (r = 0.68; p < 0.001) and postoperatively (r = 0.77; p < 0.001) and for the change in the scores (r = 0.61; p < 0.001). Three different models (preoperative, postoperative, and change) were created. There were no significant differences between the actual and predicted mean EQ-5D-3L utilities at any timepoint or for change in the scores (p > 0.090) in the validation cohort. There was a significant correlation between the actual and predicted EQ-5D-3L utilities preoperatively (r = 0.63; p < 0.001) and postoperatively (r = 0.77; p < 0.001) and for the change in the scores (r = 0.56; p < 0.001). Bland-Altman plots demonstrated that a lower utility was overestimated, and higher utility was underestimated. The individual predicted EQ-5D-3L that was within ± 0.05 and ± 0.010 (minimal clinically important difference (MCID)) of the actual EQ-5D-3L varied between 13% to 35% and 26% to 64%, respectively, according to timepoint assessed and change in the scores, but was not significantly different between the modelling and validation cohorts (p ≥ 0.148). Conclusion. The OKS can be used to estimate EQ-5D-3L. Predicted individual patient utility error beyond the MCID varied from one-third to two-thirds depending on timepoint assessed, but the mean for a cohort did not differ and could be employed for this purpose. Cite this article: Bone Jt Open 2022;3(7):573–581


The Bone & Joint Journal
Vol. 106-B, Issue 4 | Pages 394 - 400
1 Apr 2024
Kjærvik C Gjertsen J Stensland E Dybvik EH Soereide O

Aims. The aims of this study were to assess quality of life after hip fractures, to characterize respondents to patient-reported outcome measures (PROMs), and to describe the recovery trajectory of hip fracture patients. Methods. Data on 35,206 hip fractures (2014 to 2018; 67.2% female) in the Norwegian Hip Fracture Register were linked to data from the Norwegian Patient Registry and Statistics Norway. PROMs data were collected using the EuroQol five-dimension three-level questionnaire (EQ-5D-3L) scoring instrument and living patients were invited to respond at four, 12, and 36 months post fracture. Multiple imputation procedures were performed as a model to substitute missing PROM data. Differences in response rates between categories of covariates were analyzed using chi-squared test statistics. The association between patient and socioeconomic characteristics and the reported EQ-5D-3L scores was analyzed using linear regression. Results. The median age was 83 years (interquartile range 76 to 90), and 3,561 (10%) lived in a healthcare facility. Observed mean pre-fracture EQ-5D-3L index score was 0.81 (95% confidence interval 0.803 to 0.810), which decreased to 0.66 at four months, to 0.70 at 12 months, and to 0.73 at 36 months. In the imputed datasets, the reduction from pre-fracture was similar (0.15 points) but an improvement up to 36 months was modest (0.01 to 0.03 points). Patients with higher age, male sex, severe comorbidity, cognitive impairment, lower income, lower education, and those in residential care facilities had a lower proportion of respondents, and systematically reported a lower health-related quality of life (HRQoL). The response pattern of patients influenced scores significantly, and the highest scores are found in patients reporting scores at all observation times. Conclusion. Hip fracture leads to a persistent reduction in measured HRQoL, up to 36 months. The patients’ health and socioeconomic status were associated with the proportion of patients returning PROM data for analysis, and affected the results reported. Observed EQ-5D-3L scores are affected by attrition and selection bias mechanisms and motivate the use of statistical modelling for adjustment. Cite this article: Bone Joint J 2024;106-B(4):394–400


The Bone & Joint Journal
Vol. 103-B, Issue 11 | Pages 1695 - 1701
1 Nov 2021
Currier JH Currier BH Abdel MP Berry DJ Titus AJ Van Citters DW

Aims. Wear of the polyethylene (PE) tibial insert of total knee arthroplasty (TKA) increases the risk of revision surgery with a significant cost burden on the healthcare system. This study quantifies wear performance of tibial inserts in a large and diverse series of retrieved TKAs to evaluate the effect of factors related to the patient, knee design, and bearing material on tibial insert wear performance. Methods. An institutional review board-approved retrieval archive was surveyed for modular PE tibial inserts over a range of in vivo duration (mean 58 months (0 to 290)). Five knee designs, totalling 1,585 devices, were studied. Insert wear was estimated from measured thickness change using a previously published method. Linear regression statistical analyses were used to test association of 12 patient and implant design variables with calculated wear rate. Results. Five patient-specific variables and seven implant-specific variables were evaluated for significant association with lower insert wear rate. Six were significant when controlling for other factors: greater patient age, female sex, shorter duration in vivo, polished tray, highly cross-linked PE (HXLPE), and constrained knee design. Conclusion. This study confirmed that knee wear rate increased with duration in vivo. Older patients and females had significantly lower wear rates. Polished modular tibial tray surfaces, HXLPE, and constrained TKA designs were device design factors associated with significantly reduced wear rate. Cite this article: Bone Joint J 2021;103-B(11):1695–1701


Bone & Joint Open
Vol. 3, Issue 4 | Pages 291 - 301
4 Apr 2022
Holleyman RJ Lyman S Bankes MJK Board TN Conroy JL McBryde CW Andrade AJ Malviya A Khanduja V

Aims. This study uses prospective registry data to compare early patient outcomes following arthroscopic repair or debridement of the acetabular labrum. Methods. Data on adult patients who underwent arthroscopic labral debridement or repair between 1 January 2012 and 31 July 2019 were extracted from the UK Non-Arthroplasty Hip Registry. Patients who underwent microfracture, osteophyte excision, or a concurrent extra-articular procedure were excluded. The EuroQol five-dimension (EQ-5D) and International Hip Outcome Tool 12 (iHOT-12) questionnaires were collected preoperatively and at six and 12 months post-operatively. Due to concerns over differential questionnaire non-response between the two groups, a combination of random sampling, propensity score matching, and pooled multivariable linear regression models were employed to compare iHOT-12 improvement. Results. A total of 2,025 labral debridements (55%) and 1,659 labral repairs (45%) were identified. Both groups saw significant (p < 0.001) EQ-5D and iHOT-12 gain compared to preoperative scores at 12 months (iHOT-12 improvement: labral repair = +28.7 (95% confidence interval (CI) 26.4 to 30.9), labral debridement = +24.7 (95% CI 22.5 to 27.0)), however there was no significant difference between procedures after multivariable modelling. Overall, 66% of cases achieved the minimum clinically important difference (MCID) and 48% achieved substantial clinical benefit at 12 months. Conclusion. Both labral procedures were successful in significantly improving early functional outcome following hip arthroscopy, regardless of age or sex. Labral repair was associated with superior outcomes in univariable analysis, however there was no significant superiority demonstrated in the multivariable model. Level of evidence: III. Cite this article: Bone Jt Open 2022;3(4):291–301


The Bone & Joint Journal
Vol. 106-B, Issue 4 | Pages 336 - 343
1 Apr 2024
Haertlé M Becker N Windhagen H Ahmad SS

Aims. Periacetabular osteotomy (PAO) is widely recognized as a demanding surgical procedure for acetabular reorientation. Reports about the learning curve have primarily focused on complication rates during the initial learning phase. Therefore, our aim was to assess the PAO learning curve from an analytical perspective by determining the number of PAOs required for the duration of surgery to plateau and the accuracy to improve. Methods. The study included 118 consecutive PAOs in 106 patients. Of these, 28 were male (23.7%) and 90 were female (76.3%). The primary endpoint was surgical time. Secondary outcome measures included radiological parameters. Cumulative summation analysis was used to determine changes in surgical duration. A multivariate linear regression model was used to identify independent factors influencing surgical time. Results. The learning curve in this series was 26 PAOs in a period of six months. After 26 PAO procedures, a significant drop in surgical time was observed and a plateau was also achieved. The mean duration of surgery during the learning curve was 103.8 minutes (SD 33.2), and 69.7 minutes (SD 18.6) thereafter (p < 0.001). Radiological correction of acetabular retroversion showed a significant improvement after having performed a total of 93 PAOs, including anteverting PAOs on 35 hips with a retroverted acetabular morphology (p = 0.005). Several factors were identified as independent variables influencing duration of surgery, including patient weight (β = 0.5 (95% confidence interval (CI) 0.2 to 0.7); p < 0.001), learning curve procedure phase of 26 procedures (β = 34.0 (95% CI 24.3 to 43.8); p < 0.001), and the degree of lateral correction expressed as the change in the lateral centre-edge angle (β = 0.7 (95% CI 0.001 to 1.3); p = 0.048). Conclusion. The learning curve for PAO surgery requires extensive surgical training at a high-volume centre, with a minimum of 50 PAOs per surgeon per year. This study defined a cut-off value of 26 PAO procedures, after which a significant drop in surgical duration occurred. Furthermore, it was observed that a retroverted morphology of the acetabulum required a greater number of procedures to acquire proficiency in consistently eliminating the crossover sign. These findings are relevant for fellows and fellowship programme directors in establishing the extent of training required to impart competence in PAO. Cite this article: Bone Joint J 2024;106-B(4):336–343


Bone & Joint Research
Vol. 10, Issue 11 | Pages 734 - 741
1 Nov 2021
Cheng B Wen Y Yang X Cheng S Liu L Chu X Ye J Liang C Yao Y Jia Y Zhang F

Aims. Despite the interest in the association of gut microbiota with bone health, limited population-based studies of gut microbiota and bone mineral density (BMD) have been made. Our aim is to explore the possible association between gut microbiota and BMD. Methods. A total of 3,321 independent loci of gut microbiota were used to calculate the individual polygenic risk score (PRS) for 114 gut microbiota-related traits. The individual genotype data were obtained from UK Biobank cohort. Linear regressions were then conducted to evaluate the possible association of gut microbiota with L1-L4 BMD (n = 4,070), total BMD (n = 4,056), and femur total BMD (n = 4,054), respectively. PLINK 2.0 was used to detect the single-nucleotide polymorphism (SNP) × gut microbiota interaction effect on the risks of L1-L4 BMD, total BMD, and femur total BMD, respectively. Results. We detected five, three, and seven candidate gut microbiota-related traits for L1-L4 BMD, total BMD, and femur BMD, respectively, such as genus Dialister (p = 0.004) for L1-L4 BMD, and genus Eisenbergiella (p = 0.046) for total BMD. We also detected two common gut microbiota-related traits shared by L1-L4 BMD, total BMD, and femur total BMD, including genus Escherichia Shigella and genus Lactococcus. Interaction analysis of BMD detected several genes that interacted with gut microbiota, such as phospholipase D1 (PLD1) and endomucin (EMCN) interacting with genus Dialister in total BMD, and COL12A1 and Discs Large MAGUK Scaffold Protein 2 (DLG2) interacting with genus Lactococcus in femur BMD. Conclusion. Our results suggest associations between gut microbiota and BMD, which will be helpful to further explore the regulation mechanism and intervention gut microbiota of BMD. Cite this article: Bone Joint Res 2021;10(11):734–741


Bone & Joint Research
Vol. 11, Issue 3 | Pages 180 - 188
1 Mar 2022
Rajpura A Asle SG Ait Si Selmi T Board T

Aims. Hip arthroplasty aims to accurately recreate joint biomechanics. Considerable attention has been paid to vertical and horizontal offset, but femoral head centre in the anteroposterior (AP) plane has received little attention. This study investigates the accuracy of restoration of joint centre of rotation in the AP plane. Methods. Postoperative CT scans of 40 patients who underwent unilateral uncemented total hip arthroplasty were analyzed. Anteroposterior offset (APO) and femoral anteversion were measured on both the operated and non-operated sides. Sagittal tilt of the femoral stem was also measured. APO measured on axial slices was defined as the perpendicular distance between a line drawn from the anterior most point of the proximal femur (anterior reference line) to the centre of the femoral head. The anterior reference line was made parallel to the posterior condylar axis of the knee to correct for rotation. Results. Overall, 26/40 hips had a centre of rotation displaced posteriorly compared to the contralateral hip, increasing to 33/40 once corrected for sagittal tilt, with a mean posterior displacement of 7 mm. Linear regression analysis indicated that stem anteversion needed to be increased by 10.8° to recreate the head centre in the AP plane. Merely matching the native version would result in a 12 mm posterior displacement. Conclusion. This study demonstrates the significant incidence of posterior displacement of the head centre in uncemented hip arthroplasty. Effects of such displacement include a reduction in impingement free range of motion, potential alterations in muscle force vectors and lever arms, and impaired proprioception due to muscle fibre reorientation. Cite this article: Bone Joint Res 2022;11(3):180–188


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_13 | Pages 63 - 63
1 Nov 2021
Visscher L White J Tetsworth K McCarthy C
Full Access

Introduction and Objective. Malunion after trauma can lead to coronal plane malalignment in the lower limb. The mechanical hypothesis suggests that this alters the load distribution in the knee joint and that that this increased load may predispose to compartmental arthritis. This is generally accepted in the orthopaedic community and serves as the basis guiding deformity correction after malunion as well as congenital or insidious onset malalignment. Much of the literature surrounding the contribution of lower limb alignment to arthritis comes from cohort studies of incident osteoarthritis. There has been a causation dilemma perpetuated in a number of studies - suggesting malalignment does not contribute to, but is instead a consequence of, compartmental arthritis. In this investigation the relationship between compartmental (medial or lateral) arthritis and coronal plane malalignment (varus or valgus) in patients with post traumatic unilateral limb deformity was examined. This represents a specific niche cohort of patients in which worsened compartmental knee arthritis after extra-articular injury must rationally be attributed to malalignment. Materials and Methods. The picture archiving system was searched to identify all 1160 long leg x ray films available at a major metropolitan trauma center over a 12-year period. Images were screened for inclusion and exclusion criteria, namely patients >10 years after traumatic long bone fracture without contralateral injury or arthroplasty to give 39 cases. Alignment was measured according to established surgical standards on long leg films by 3 independent reviewers, and arthritis scores Osteoarthritis Research Society International (OARSI) and Kellegren-Lawrence (KL) were recorded independently for each compartment of both knees. Malalignment was defined conservatively as mechanical axis deviation outside of 0–20 mm medial from centre of the knee, to give 27 patients. Comparison of mean compartmental arthritis score was performed for patients with varus and valgus malalignment, using Analysis of Variance and linear regression. Results. In knees with varus malalignment there was a greater mean arthritis score in the medial compartment compared to the contralateral knee, with OARSI scores 5.69 vs 3.86 (0.32, 3.35 95% CI; p<0.05) and KL 2.92 vs 1.92 (0.38, 1.62; p<0.005). There was a similar trend in valgus knees for the lateral compartment OARSI 2.98 vs 1.84 (CI −0.16, 2.42; p=0.1) and KL 1.76 vs 1.31 (CI −0.12, 1.01; p=0.17), but the evidence was not conclusive. OARSI arthritis score was significantly associated with absolute MAD (0.7/10mm MAD, p<0.0005) and Time (0.6/decade, p=0.01) in a linear regression model. Conclusions. Malalignment in the coronal plane is correlated with worsened arthritis scores in the medial compartment for varus deformity and may similarly result in worsened lateral compartment arthritis in valgus knees. These findings support the mechanical hypothesis that arthritis may be related to altered stress distribution at the knee, larger studies may provide further conclusive evidence


Bone & Joint Open
Vol. 3, Issue 2 | Pages 145 - 151
7 Feb 2022
Robinson PG Khan S MacDonald D Murray IR Macpherson GJ Clement ND

Aims. Golf is a popular pursuit among those requiring total hip arthroplasty (THA). The aim of this study was to determine if participating in golf is associated with greater functional outcomes, satisfaction, or improvement in quality of life (QoL) compared to non-golfers. Methods. All patients undergoing primary THA over a one-year period at a single institution were included with one-year postoperative outcomes. Patients were retrospectively followed up to assess if they had been golfers at the time of their surgery. Multivariate linear regression analysis was performed to assess the independent association of preoperative golfing status on outcomes. Results. The study cohort consisted of a total of 308 patients undergoing THA, of whom 44 were golfers (14%). This included 120 male patients (39%) and 188 female patients (61%), with an overall mean age of 67.8 years (SD 11.6). Golfers had a greater mean postoperative Oxford Hip Score (OHS) (3.7 (95% confidence interval (CI) 1.9 to 5.5); p < 0.001) and EuroQol visual analogue scale (5.5 (95% CI 0.1 to 11.9); p = 0.039). However, there were no differences in EuroQoL five-dimension score (p = 0.124), pain visual analogue scale (p = 0.505), or Forgotten Joint Score (p = 0.215). When adjusting for confounders, golfers had a greater improvement in their Oxford Hip Score (2.7 (95% CI 0.2 to 5.3); p < 0.001) compared to non-golfers. Of the 44 patients who reported being golfers at the time of their surgery, 32 (72.7%) returned to golf and 84.4% of those were satisfied with their involvement in golf following surgery. Those who returned to golf were more likely to be male (p = 0.039) and had higher (better) preoperative health-related QoL (p = 0.040) and hip-related functional scores (p = 0.026). Conclusion. Golfers had a greater improvement in their hip-specific function compared to non-golfers after THA. However, less than three-quarters of patients return to golf, with male patients and those who had greater preoperative QoL or hip-related function being more likely to return to play. Cite this article: Bone Jt Open 2022;3(2):145–151


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_4 | Pages 6 - 6
8 Feb 2024
Ammori M Hancock S Talukdar P Munro C Johnston A
Full Access

The objectives of our study were to compare patient reported outcome measures between manual and robotic-assisted total hip arthroplasty. Between 1st May 2021 and 31st August 2022, 539 consecutive patients who underwent 564 primary total hip arthroplasties were identified from the local registry database. Data were prospectively collected, and included patient demographics, American Society of Anaesthesiologists (ASA) grade, surgical approach, robotic-assistance, Oxford Hip Score (OHS), EQ-5D-3L and EQ-VAS pre-operatively and at twelve months. Robotic-assistance, compared against manual total hip arthroplasty, was associated with an enhanced median (interquartile range) OHS (46 [42 – 48] vs 43 [36 – 47], p-value < 0.001), EQ-5D-3L (5 [5 – 7] vs 6 [5 – 8], p-value 0.002), and EQVAS (90 [75 – 95] vs 80 [70 – 90], p-value 0.003) at twelve months after surgery. Robotic-assistance was confirmed to be an independent predictor of a greater OHS at twelve months on a multivariate linear regression analysis (p-value 0.001). Robotic assistance was superior to manual total hip arthroplasty in enhancing patient reported outcomes at twelve months after surgery


The Bone & Joint Journal
Vol. 103-B, Issue 8 | Pages 1380 - 1385
2 Aug 2021
Kim Y Ryu J Kim JK Al-Dhafer BAA Shin YH

Aims. The aim of this study was to assess arthritis of the basal joint of the thumb quantitatively using bone single-photon emission CT/CT (SPECT/CT) and evaluate its relationship with patients’ pain and function. Methods. We retrospectively reviewed 30 patients (53 hands) with symptomatic basal joint arthritis of the thumb between April 2019 and March 2020. Visual analogue scale (VAS) scores for pain, grip strength, and pinch power of both hands and Patient-Rated Wrist/Hand Evaluation (PRWHE) scores were recorded for all patients. Basal joint arthritis was classified according to the modified Eaton-Glickel stage using routine radiographs and the CT scans of SPECT/CT, respectively. The maximum standardized uptake value (SUVmax) from SPECT/CT was measured in the four peritrapezial joints and the highest uptake was used for analysis. Results. According to Eaton-Glickel classification, 11, 17, 17, and eight hands were stage 0 to I, II, III, and IV, respectively. The interobserver reliability for determining the stage of arthritis was moderate for radiographs (k = 0.41) and substantial for CT scans (k = 0.67). In a binary categorical analysis using SUVmax, pain (p < 0.001) and PRWHE scores (p = 0.004) were significantly higher in hands with higher SUVmax. Using multivariate linear regression to estimate the pain VAS, only SUVmax (B 0.172 (95% confidence interval (CI) 0.065 to 0.279; p = 0.002) showed a significant association. Estimating the variation of PRWHE scores using the same model, only SUVmax (B 1.378 (95% CI, 0.082 to 2.674); p = 0.038) showed a significant association. Conclusion. The CT scans of SPECT/CT provided better interobserver reliability than routine radiographs for evaluating the severity of arthritis. A higher SUVmax in SPECT/CT was associated with more pain and functional disabilities of basal joint arthritis of the thumb. This approach could be used to complement radiographs for the evaluation of patients with this condition. Cite this article: Bone Joint J 2021;103-B(8):1380–1385


The Bone & Joint Journal
Vol. 103-B, Issue 10 | Pages 1627 - 1632
4 Oct 2021
Farrow L Hall AJ Ablett AD Johansen A Myint PK

Aims. The aim of this study was to determine the impact of hospital-level service characteristics on hip fracture outcomes and quality of care processes measures. Methods. This was a retrospective analysis of publicly available audit data obtained from the National Hip Fracture Database (NHFD) 2018 benchmark summary and Facilities Survey. Data extraction was performed using a dedicated proforma to identify relevant hospital-level care process and outcome variables for inclusion. The primary outcome measure was adjusted 30-day mortality rate. A random forest-based multivariate imputation by chained equation (MICE) algorithm was used for missing value imputation. Univariable analysis for each hospital level factor was performed using a combination of Tobit regression, Siegal non-parametric linear regression, and Mann-Whitney U test analyses, dependent on the data type. In all analyses, a p-value < 0.05 denoted statistical significance. Results. Analyses included 176 hospitals, with a median of 366 hip fracture cases per year (interquartile range (IQR) 280 to 457). Aggregated data from 66,578 patients were included. The only identified hospital-level variable associated with the primary outcome of 30-day mortality was hip fracture trial involvement (no trial involvement: median 6.3%; trial involvement: median 5.7%; p = 0.039). Significant key associations were also identified between prompt surgery and presence of dedicated hip fracture sessions; reduced acute length of stay and both a higher number of hip fracture cases per year and more dedicated hip fracture operating lists; Best Practice Tariff attainment and greater number of hip fracture cases per year, more dedicated hip fracture operating lists, presence of a dedicated hip fracture ward, and hip fracture trial involvement. Conclusion. Exploratory analyses have identified that improved outcomes in hip fracture may be associated with hospital-level service characteristics, such as hip fracture research trial involvement, larger hip fracture volumes, and the use of theatre lists dedicated to hip fracture surgery. Further research using patient level data is warranted to corroborate these findings. Cite this article: Bone Joint J 2021;103-B(10):1627–1632


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_11 | Pages 43 - 43
1 Nov 2022
Nebhani N Kumar G
Full Access

Abstract. Extended Trochanteric Osteotomy (ETO) improves surgical exposure and aids femoral stem and bone cement removal in Revision Total Hip Replacement (RTHR) surgery. The aim of this study was to identify healing rates and complications of ETO in RTHR. Methods. From 2012 to 2019 we identified patients who underwent ETO for RTHR. Data collected demographics, BMI, diabetes, anticoagulants, indication for ETO, surgical approach, length of ETO and complications. Descriptive analysis of patient demographics, multiple linear regression analysis was performed to assess ETO complications. Results. There were 63 patients with an average age of 69 years. Indications for ETO were aseptic loosening (30), infection (15), periprosthetic fracture (9), recurrent dislocation (5), broken implant (4). There were 44 cemented and 19 uncemented femoral stem that underwent ETO. Average time from index surgery was 12 years (less than a year to 38 years). All procedures were through posterolateral approach and all ETO were stabilised with cables. Average length of ETO was 12.5cm. BMI varied from 18 to 37. There were 5 diabetics and 16 on anticoagulants. All but one ETO went on to unite. Other complications included infection, dislocations, lateral thigh pain and significant limp. Discussion. Fixation of ETO can be with either wires or cables or plate with cables/screws. Advantages of cables are no irritation over greater trochanter, no disruption of gluteus medius/vastus lateralis continuity, reproducible tension in cables and use of torque limiter minimises loss of tension in cables


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_13 | Pages 17 - 17
7 Aug 2023
Arthur L Ghosh P Mohammad H Campi S Murray D Mellon S
Full Access

Abstract. Introduction. The Oxford Unicompartmental Knee Replacement's (OUKR's) fully-congruent design minimises polyethylene wear. Consequently, wear is a rare failure mechanism. Phase-3 OUKR linear wear at 5 years was higher than previous OUKR phases, but very low compared to fixed-bearing UKRs. This study aimed to measure OUKR bearing wear at 10 years and investigate factors that may affect wear. Methodology. Bearing thickness for 39 OUKRs from a randomised study was calculated using radiostereometric analysis at regular intervals up to 10 years. Data for 39 and 29 OUKRs was available at 5 and 10 years, respectively. As creep occurs early, wear rate was calculated using linear regression between 6 months and 10 years. Relationships between wear and patient factors, fixation method, Oxford Knee Score (OKS), bearing position, and component position were analysed. Results. The mean wear rate was 0.06mm/year. Fixation method, age, OKS, component size, and bearing size had no correlation with wear. A higher BMI was associated with lower wear (p=0.01). Bearings more than 4mm from the wall had significantly more wear (p=0.04) than those less than 4mm from the wall. There was a linear correlation between the femoral component contact area on the bearing and wear (p=0.04). Conclusions. Phase-3 bearing wear rate is constant, significantly higher than previous OUKR phases at 10 years, and may increase the risk of long-term bearing failure. To minimise complications associated with wear, size 4 bearings should be used in young patients and manufacturing bearings from more durable, highly crosslinked polyethylene should be studied


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_9 | Pages 86 - 86
17 Apr 2023
Aljuaid M Alzahrani S Shurbaji S
Full Access

Acetabular morphology and orientation differs from ethnic group to another. Thus, investigating the natural history of the parameters that are used to assess both was a matter of essence. Nevertheless, clarification the picture of normal value in our society was the main aim of this study. However, Acetabular head index (AHI) and center edge angle (CEA) were the most sensitive indicative parameters for acetabular dysplasia. Hence, they were the main variables used in evaluation of acetabular development. A cross-sectional retrospective study that had been done in a tertiary center. Computed tomography abdomen scouts’ radiographs of non-orthopedics patients were included. They had no history of pelvic or hips’ related symptoms or fractures in femur or pelvis. Images’ reports were reviewed to exclude those with tumors in the femur or pelvic bones. A total of 81 patients was included with 51% of them were males. The mean of age was 10.38± 3.96. CEA was measured using Wiberg technique, means of CEA were 33.71±6.53 and 36.50±7.39 for males and females, respectively. Nonetheless, AHI means were 83.81±6.10 and 84.66±4.17 for males and females, respectively. On the other hand, CEA was increasing by a factor 0.26 for each year (3-18, range). In addition, positive significant correlation was detected between CEA and age as found by linear regression r 2 0.460 (f(df1,79) =21.232, P ≤0.0001). Also, Body mass index (BMI) was positively correlated with CEA r 0.410, P 0.004). This study shows that obesity and aging are linked to increased CEA. Each ethnic group has its own normal values that must be studied to avoid premature diagnosis


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_12 | Pages 32 - 32
23 Jun 2023
Jacobs JJ Agarwal P Leurgans SE Agrawal S Ayton S Bush AI Hall DJ Schneider J Pourzal R
Full Access

Both total joint arthroplasty (TJA) and Alzheimer's Disease (AD) are prevalent in elderly populations. It is the goal of this study to determine if the presence of implant metals originating from TJA correlates with the onset with higher implant metal content in the brain and AD pathology. Tissue samples from four brain regions of 701 (229 with TJA) participants from an ongoing longitudinal cohort study (Rush Memory and Aging Project) was analyzed including the inferior-temporal-cortex (ITC), which is associated with early onset of AD. Implant metal (Co, Cr, Mo, Ti, Al) content was determined by ICP-MS. Comparisons were conducted between the no-TJA-group and a TJA group. Due to the higher likelihood of Co release the TJA group was further differentiated in a THA (N=146) and a TKA/TSA (N=83) group. Diffuse and neuritic amyloid plaques and phosphorylated tau were assessed and summarized as standard measures of AD pathology. We used separate linear regression models adjusted for age, sex, education, and APOɛ4-status for the associations of all metals (log-transformed) with global AD pathology, amyloid plaques, and phosphorylated tau. The THA group had higher cobalt content across all brain regions (p=0.003) and within the ITC (p=0.051) compared to the no-TJA group, whereas the TKA/TSA group did not. Across all tissue samples, Co was associated with higher amyloid load (β=0.35, p=0.027), phosphorylated tau (β=0.47, p=0.011), and global AD pathology (β=0.19, 0.0004) in the ITC. The presence of TJA itself was not associated with AD pathology. We showed that only Co content was higher within the ITC in persons with THA. We found among all tested metals that Co was consistently associated with AD pathology. Although we found an association of cobalt with AD pathology, the cross-sectional nature of this study does not allow the determination of cause and effect


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_6 | Pages 6 - 6
20 Mar 2023
Hall A Penfold R Duckworth A Clement N MacLullich A
Full Access

Hip fracture patients are vulnerable to delirium. This study examined the associations between delirium and outcomes including mortality, length of stay, post-discharge care requirements, and readmission. This cohort study collected validated healthcare data for all hip fracture patients aged ≥50 years that presented to a high-volume centre between March 2020-November 2021. Variables included: demographics, delirium status, COVID-19 status, treatment factors, and outcome measures. Wilcoxon rank sum or Chi-squared tests were used for baseline differences, Cox proportional hazard regression for mortality, logistic regression for post-discharge care requirements and readmission, and linear regression for length of stay. Analyses were adjusted for age, sex, deprivation, pre-fracture residence type and COVID-19. There were 1822 patients (mean age 81 years; 72% female) of which 496/1822 (27.2%) had delirium (4AT score ≥4). Of 371/1822 (20.4%) patients that died within 180 days of admission, 177/371 (47.7%) had delirium during the acute stay. Delirium was associated with an increased 30- and 180-day mortality risk (adjusted HR 1.74 (95%CI 1.15-2.64; p=0.009 and 1.74 (1.36-2.22; p<0.001), respectively), ten day longer total inpatient stay [adj. B.coef 9.80 (standard error 2.26); p<0.001] and three-fold greater odds of higher care requirements on discharge [Odds Ratio 3.07 (95% Confidence Interval 2.27-4.15; p<0.001)]. More than a quarter of patients had delirium during the hip fracture stay, and this was independently associated with increased mortality, longer length of stay, and higher post-discharge care requirements. These findings are relevant for prognostication and service planning, and emphasise the importance of effective delirium screening and evidence-based interventions in this vulnerable population


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 3 - 3
1 Dec 2022
Getzlaf M Sims L Sauder D
Full Access

Intraoperative range of motion (ROM) radiographs are routinely taken during scaphoidectomy and four corner fusion surgery (S4CF) at our institution. It is not known if intraoperative ROM predicts postoperative ROM. We hypothesize that patients with a greater intra-operativeROM would have an improved postoperative ROM at one year, but that this arc would be less than that achieved intra- operatively. We retrospectively reviewed 56 patients that had undergone S4CF at our institution in the past 10 years. Patients less than 18, those who underwent the procedure for reasons other than arthritis, those less than one year from surgery, and those that had since undergone wrist arthrodesis were excluded. Intraoperative ROM was measured from fluoroscopic images taken in flexion and extension at the time of surgery. Patients that met criteria were then invited to take part in a virtual assessment and their ROM was measured using a goniometer. T-tests were used to measure differences between intraoperative and postoperative ROM, Pearson Correlation was used to measure associations, and linear regression was conducted to assess whether intraoperative ROM predicts postoperative ROM. Nineteen patients, two of whom had bilateral surgery, agreed to participate. Mean age was 54 and 14 were male and 5 were male. In the majority, surgical indication was scapholunate advanced collapse; however, two of the participants had scaphoid nonunion advanced collapse. No difference was observed between intraoperative and postoperative flexion. On average there was an increase of seven degrees of extension and 12° arc of motion postoperatively with p values reaching significance Correlation between intr-operative and postoperative ROM did not reach statistical significance for flexion, extension, or arc of motion. There were no statistically significant correlations between intraoperative and postoperative ROM. Intraoperative ROM radiographs are not useful at predicting postoperative ROM. Postoperative extension and arc of motion did increase from that measured intraoperatively


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_8 | Pages 49 - 49
11 Apr 2023
Speirs A Melkus G Rakhra K Beaule P
Full Access

Femoroacetabular impingement (FAI) results from a morphological deformity of the hip and is associated with osteoarthritis (OA). Increased bone mineral density (BMD) is observed in the antero-superior acetabulum rim where impingement occurs. It is hypothesized that the repeated abnormal contact leads to damage of the cartilage layer, but could also cause a bone remodelling response according to Wolff's Law. Thus the goal of this study was to assess the relationship between bone metabolic activity measured by PET and BMD measured in CT scans. Five participants with asymptomatic cam deformity, three patients with uni-lateral symptomatic cam FAI and three healthy controls were scanned in a 3T PET-MRI scanner following injection with [18F]NaF. Bone remodelling activity was quantified with Standard Uptake Values (SUVs). SUVmax was analyzed in the antero-superior acetabular rim, femoral head and head-neck junction. In these same regions, BMD was calculated from CT scans using the calibration phantom included in the scan. The relationship between SUVmax and BMD from corresponding regions was assessed using the coefficient of determination (R. 2. ) from linear regression. High bone activity was seen in the cam deformity and acetabular rim. SUVmax was negatively correlated with BMD in the antero-superior region of the acetabulum (R. 2. =0.30, p=0.08). SUVmax was positively correlated with BMD in the antero-superior head-neck junction of the femur (R. 2. =0.359, p=0.067). Correlations were weak in other regions. Elevated bone turnover was seen in patients with a cam deformity but the relationship to BMD was moderate. This study demonstrates a pathomechanism of hip degeneration associated with FAI deformities, consistent with Wolff's law and the proposed mechanical cause of hip degeneration in FAI. [18F]-NaF PET SUV may be a biomarker of degeneration, especially in early stages of degeneration, when joint preservation surgery is likely to be the most successful


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_6 | Pages 10 - 10
2 May 2024
Amer M Smith C Kumar KHS Malviya A
Full Access

Adult hip dysplasia AHD is a complex 3D pathology of lateral coverage, version and/or volume and is often associated with increased femoral anteversion. The Mckibbin index MI is the combination of acetabular version AV and femoral version FV and is used as a measure of anterior hip Stability/ Impingement(1). The Bernese Periacetabular osteotomy PAO is a powerful tool in treating AHD, but it does not address FV. De-rotational femoral osteotomies FO increases risk of complications, operative time and might condemn the patient to Secondary osteotomies to balance the gait. We aim to investigate the effect of MI and FV on PROMs in patients undergoing PAO only. 593 PAOs identified on the Local Hip preservation registry between 01/2013 and 7/2023. PAOs for retroversion, residual Perthes and those combined with FO were excluded. Patients with no available PROMS at 2 years were excluded. Independent variables were collected from E-notes and imaging including MI and FV. A multiple linear regression analysis was performed against preoperative iHot12, and iHot12 change at 2years. The mean FV was 18.86± 12.4 SD. Mean MI was 36.07, SD 15.36. Mean preop iHot12 score was 29.83 ± 17.38 SD. Mean change in iHot12 at 2 years was+36.47 ± 28.44 SD. Females and a higher BMI were statistically correlated to a lower preoperative iHot12. A lower preop iHot12 score and a higher preop AI were correlated to a bigger change in iHot12 at 2years with statistical significance. MI and FV were not found to have a statistically significant correlation with Outcome measures,. An increased Mckibbin index and femoral anteversion were not correlated with worse outcomes at two years. PAO alone in the presence of increased femoral anteversion avoids risks associated with FO which can be performed later if required


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_9 | Pages 2 - 2
1 Jun 2021
Tang H Wang S Zhou Y Li Y Zhao Y Shi H
Full Access

Introduction. The functional ante-inclination (AI) of the cup after total hip arthroplasty (THA) is a key component in the combined sagittal index (CSI) to predict joint stability after THA. To accurately predict AI, we deducted a mathematic algorithm between the radiographic anteversion (RA), radiographic inclincation (RI), pelvic tilting (PT), and AI. The current study aims (1) to validate the mathematic algorithm; (2) to convert the AI limits in the CSI index (standing AI ≤ 45°, sitting AI ≥ 41°) into coronal functional safe zone (CFSZ) and explore the influences of the stand-to-sit pelvic motion (PM) and pelvic incidence (PI) on CFSZ; (3) to locate a universal cup orientation that always fulfill the AI criteria of CSI safe zone for all patients or subgroups of PM(PM ≤ 10°, 10° < PM ≤ 30°, and PM > 30°) and PI (PI≤ 41°, 41°< PI ≤ 62°, and PI >62°), respectively. Methods. A 3D printed phantom pelvic model was designed to simulate changing PT values. An acetabular cup was implanted with different RA, RI, and PT settings using robot assisted technique. We enrolled 100 consecutive patients who underwent robot assisted THA from April, 2019 to June, 2019 in our hospital. EOS images before THA and at 6-month follow-up were collected. AI angles were measured on the lateral view radiographs as the reference method. Mean absolute error (MAE), Bland-Altman analysis and linear regression were conducted to assess the accuracy of the AI algorithm for both the phantom and patient radiographic studies. The 100 patients were classified into three subgroups by PM and PI, respectively. Linear regression and ANOVA analysis were conducted to explore the relationship between the size of CFSZ, and PM and PI, respectively. Intersection of the CFSZ was conducted to identify if any universal cup orientation (RA, RI) existed for the CSI index. Results. The mathematic algorithm for calculating AI based on RI, RA, and PT is highly accurate according to the phantom and patient radiographic study. CFSZ size corresponds linearly with PM (R² = 0.638) and PI (R² = 0.129), respectively. There are significant differences in the size of CFSZ, as well as in the intersection of CFSZ and LSZ, between the subgroups of PM and PI, respectively (P<0.017). There is no universal cup orientations could be identified to fulfill the AI limits of the CSI index for all the 100 patients or any of the three subgroups, according to either PM or PI. Conclusions. The cup target orientation should be individualized. The validated algorithm between AI and RA, RI, and PT parameters can serve as the quantitative tool for patient-specific optimization of functional cup AI in different postures


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_2 | Pages 8 - 8
1 Mar 2021
Hulme CH Perry J Roberts S Gallacher P Jermin P Wright KT
Full Access

Abstract. Objectives. The ability to predict which patients will improve following routine surgeries aimed at preventing the progression of osteoarthritis is needed to aid patients being stratified to receive the most appropriate treatment. This study aimed to investigate the potential of a panel of biomarkers for predicting (prior to treatment) the clinical outcome following treatment with microfracture or osteotomy. Methods. Proteins known to relate to OA severity, with predictive value in autologous cell implantation treatment or that had been identified in proteomic analyses (aggrecanase-1/ ADAMTS-4, cartilage oligomeric matrix protein (COMP), hyaluronic acid (HA), Lymphatic Vessel Endothelial Hyaluronan Receptor-1, matrix metalloproteinases-1 and −3, soluble CD14, S100 calcium binding protein A13 and 14-3-3 protein theta) were assessed in the synovial fluid (SF) of 19 and 13 patients prior to microfracture or osteotomy, respectively, using commercial immunoassays. Levels of COMP and HA were measured in the plasma of these patients. To find predictors of postoperative function, multiple linear regression analyses were performed. Results. Linear regression analyses demonstrated that a lower concentration of HA in pre-operative SF was predictive of improved knee function (higher Lysholm score) following microfracture surgery. Further, lower pre-operative activity of ADAMTS-4 in SF was a significant, independent predictor of higher post-operative Lysholm score (improved joint function) following osteotomy surgery. Conclusion. This study is novel in identifying biomarkers with the potential to predict clinical outcome in patients treated with microfracture or osteotomy of the knee. Lower concentrations of HA and undetectable activity of ADAMTS-4 in the joint fluid of individuals with cartilage defects/early-OA may be used in algorithms to stratify patients to the most appropriate surgery. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_7 | Pages 53 - 53
1 Jul 2022
Kurien T Arendt-Nielsen L Graven-Nielsen T Kerslake R Scammell B Petersen K
Full Access

Abstract. Background. Around 5–15% of patients will experience chronic postoperative pain after total knee replacement (TKR) surgery but the source of the pain is unknown. The aim of this study was to assesses patients six months after TKR using magnetic resonance imaging (MRI) of the knee, pain sensory profiles and assessments of pain catastrophizing thoughts. Methods. Forty-six patients had complete postoperative data and were included. MRI findings were scored according to the MRI Osteoarthritis Knee Score (MOAKS) recommendation for Hoffa synovitis, effusion size and bone marrow lesions. Pain sensory profiles included the assessment of pressure pain thresholds (PPTs), temporal summation of pain (TSP) and conditioned pain modulation (CPM). Pain catastrophizing was assessed using the pain catastrophizing scale (PCS). Clinical pain was evaluated using a visual analog scale (VAS, 0–10cm) and groups of moderate-to-severe (VAS>3) and non-to-mild postoperative pain (VAS≤3) were identified. Results. Patients with moderate-to-severe postoperative pain demonstrated higher grades of Hoffa synovitis (P<0.001) and effusion size (P<0.001), lower PPTs (P=0.039), higher TSP (P=0.001) and lower CPM (P=0.014) when compared to patients with non-to-mild postoperative pain. No differences were found in PCS scores. Linear regression models found TSP (P=0.013), PCS (P<0.001), Hoffa synovitis (P=0.036) and effusion size (P=0.003) as independent parameters contributing to the postoperative pain severity. Conclusion. These finding indicate that chronic postoperative after TKR is a combination of joint-related synovitis and effusion in combination with sensitization of central pain mechanisms and pain catastrophizing thoughts


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_8 | Pages 58 - 58
11 Apr 2023
Jansen M Salzlechner C Barnes E DiFranco M Custers R Watt F Vincent T Lafeber F Mastbergen S
Full Access

Knee joint distraction (KJD) has been associated with clinical and structural improvement and synovial fluid (SF) marker changes. However, structural changes have not yet been shown satisfactorily in regular care, since radiographic acquisition was not fully standardized. AI-based modules have shown great potential to reduce reading time, increase inter-reader agreement and therefore function as a tool for treatment outcome assessment. The objective was to analyse structural changes after KJD in patients using this AI-based measurement method, and relate these changes to clinical outcome and SF markers. 20 knee OA patients (<65 years old) were included in this study. KJD treatment was performed using an external fixation device, providing 5 mm distraction for 6 weeks. SF was aspirated before, during and immediately after treatment. Weight-bearing antero-posterior knee radiographs and WOMAC questionnaires were collected before and ~one year after treatment. Radiographs were analysed with the Knee Osteoarthritis Labelling Assistant (KOALA, IB Lab GmbH, Vienna, Austria), and 10 pre-defined biomarker levels in SF were measured by immunoassay. Radiographic one-year changes were analysed and linear regression was used to calculate associations between changes in standardized joint space width (JSW) and WOMAC, and changes in JSW and SF markers. After treatment, radiographs showed an improvement in Kellgren-Lawrence grade in 7 of 16 patients that could be evaluated; 3 showed a worsening. Joint space narrowing scores and continuous JSW measures improved especially medially. A greater improvement in JSW was significantly associated with a greater improvement in WOMAC pain (β=0.64;p=0.020). A greater increase in MCP1 (β=0.67;p=0.033) and lower increase in TGFβ1 (β=-0.787;p=0.007) were associated with JSW improvement. Despite the small number of patients, also in regular care KJD treatment shows joint repair as measured automatically on radiographs, significantly associated with certain SF marker change and even with clinical outcome


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_15 | Pages 22 - 22
7 Aug 2024
Saunders F Parkinson J Aspden R Cootes T Gregory J
Full Access

Background. Lateral lumbar spine statistical shape models (SSM) have been used previously to describe associations with osteoarthritis and back pain. However, associations with factors such as osteoporosis, menopause and parity have not been explored. Methods and Results. A 143-point SSM, describing L1 to the top of L5, was applied to lateral spine iDXA scans from UK Biobank. Associations with self-reported osteoporosis, menopause, parity and back pain and the first 10 modes of variation were examined using adjusted binary logistic regression or linear regression (adjusted for age, height, weight and total spine BMD). We report odds ratios with 95% confidence intervals for each standard deviation change in mode. Complete data were available for 2494 women. Mean age was 61.5 (± 7.4) years. 1369 women reported going through menopause, 96 women self-reported osteoporosis and 339 women reported chronic back pain. 80% of women reported at least 1 live birth. Lumbar spine shape was not associated with back pain in this cohort. Two modes were associated with menopause (modes 1 & 2), 1 mode with parity (mode 1) and 2 modes with osteoporosis (modes 3 & 5). Mode 1 (43.6% total variation), describing lumbar curvature was positively associated with both menopause [OR 1.15 95% CI 1.00–1.33, p=0.05] and parity [OR 1.058 95% CI 1.03–1.0, p=0.01]. Mode 3, describing decreased vertebral height was positively associated with osteoporosis [OR 1.40 95% CI 1.14–1.73, p=0.001]. Conclusion. Menopause and parity were associated with a curvier lumbar spine and osteoporosis with decreased vertebral height. Shape was not associated with back pain. No conflicts of interest.  . Sources of funding. Wellcome Trust collaborative award ref 209233


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_15 | Pages 37 - 37
7 Aug 2024
Wilson M Cole A Hewson D Hind D Hawksworth O Hyslop M Keetharuth A Macfarlane A Martin B McLeod G Rombach I Swaby L Tripathi S Wilby M
Full Access

Background. Over 55,000 spinal operations are performed annually in the NHS. Effective postoperative analgesia facilitates early mobilisation and assists rehabilitation and hospital discharge, but is difficult to achieve with conventional, opioid-based, oral analgesia. The clinical and cost-effectiveness of two alternative techniques, namely intrathecal opioid and the more novel erector-spinae plane blockade, is unknown. The Pain Relief After Instrumented Spinal Surgery (PRAISE) trial aims to evaluate these techniques. Methods. PRAISE is a multicentre, prospective, parallel group, patient-blinded, randomised trial, seeking to recruit 456 adult participants undergoing elective, posterior lumbar-instrumented spinal surgery from up to 25 NHS hospitals. Participants will be randomised 1:1:1 to receive (1) Usual Care with local wound infiltration, (2) Intrathecal Opioid plus Usual Care with local wound infiltration or (3) Erector Spinae Plane blockade plus Usual Care with no local wound infiltration. The primary outcome is pain on movement on a 100mm visual analogue scale at 24 hours post-surgery. Secondary outcomes include pain at rest, leg pain, quality of recovery (QoR-15), postoperative opioid consumption, time to mobilisation, length of hospital stay, health utility (EQ-5D-5L), adverse events and resource use. Parallel economic evaluation will estimate incremental cost-effectiveness ratios. Results. Differences in the primary outcome at 24 hours will be estimated by mixed-effects linear regression modelling, with fixed effects for randomisation factors and other important prognostic variables, and random effects for centre, using the as-randomised population. Treatment effects with 95% confidence intervals will be presented. Conclusion. The study is due to open in May 2024 and complete in 2026. Conflicts of Interest. No conflicts of interest declared. Sources of Funding. NIHR Health Technology Award – grant number NIHR153170. Trial presentations so far. APOMP 2023 and 2024; RCOA conference, York, November 2023; Faculty of Pain Management training day, London, February 2024


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_11 | Pages 29 - 29
7 Jun 2023
Kumar G Gangadharan R
Full Access

Clinical commissioning groups (CCG) have been replaced with ICBs that will bring together NHS and social care for the local population. ICBs are allocating contracts for long waiters for total hip replacements (THR) to hospitals that have achieved pre-covid volumes of THR, THR volumes undertaken by hospitals in 2022 should be at 2019 levels or more. Purpose of this study was to identify whether NHS hospitals in England are at a disadvantage in procuring ICB contracts for THR. THR volumes for NHS and independent sector (IND) hospitals from January 2012 to November 2022 were identified via National Joint Registry. Regional and national trend for THR volumes were identified for both NHS and IND hospitals using linear regression analysis. Trends of THR for NHS hospitals showed either stagnation or reduction in volume from 2014–2019. In 2022, nationally THR volume of NHS was 70% of 2019 (Figure 1). Trend of THR volume for IND hospitals nationally was a strong uptrend from 2012 to 2022 with a break only in 2020 due to COVID pandemic (Figure 2). Since the pandemic IND have overtaken NHS hospitals in volumes of THR undertaken. Similar picture of trends evolves when THR trends were assessed on a region by region basis. With NHS hospitals not back to pre-pandemic THR volumes, IND hospitals have a distinct advantage in securing more contracts via ICB. This in turn puts NHS hospitals at risk of taking on more complex and medically unwell patients potentially worsening NJR outcomes for NHS hospitals. The reasons for the lag in NHS hospitals’ THR volumes are multifactorial, not limited to continued bed pressures, increased emergency and unplanned admissions, staff shortages and sickness, pension taxations preventing doctors from undertaking more THR. However, lack of access to contracts from ICB will put NHS hospitals at huge financial and existential risk for elective care. For any figures or tables, please contact the authors directly


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_2 | Pages 118 - 118
10 Feb 2023
Sundaraj K Corbett J Yong Yau Tai J Salmon L Roe J
Full Access

The emergence of patient specific instrumentation has seen an expansion from simple radiographs to plan total knee arthroplasty (TKA) with modern systems using computed tomography (CT) or magnetic resonance imaging scans. Concerns have emerged regarding accuracy of these non-weight bearing modalities to assess true mechanical axis. The aim of our study was to compare coronal alignment on full length standing AP imaging generated by the EOS acquisition system with the CT coronal scout image. Eligible patients underwent unilateral or bilateral primary TKA for osteoarthritis under the care of investigating surgeon between 2017 and 2022, with both EOS X-Ray Imaging Acquisition System and CT scans performed preoperatively. Coronal mechanical alignment was measured on the supine coronal scout CT scan and the standing HKA EOS. Pre-operative lower limb coronal alignment was assessed on 96 knees prior to TKA on the supine coronal scout CT scan and the standing HKA EOS. There were 56 males (56%), and 44 right knees (44%). The mean age was 68 years (range 53-90). The mean coronal alignment was 4.7 degrees (SD 5.3) on CT scan and 4.6 degrees (SD 6.2) on EOS (p=0.70). There was a strong positive correlation of coronal alignment on CT scan and EOS (pearson. 0.927, p=0.001). The mean difference between EOS and CT scan was 0.9 degrees (SD 2.4). Less than 3 degrees variation between measures was observed in 87% of knees. On linear regression for every 1° varus increase in CT HKA alignment, the EOS HKA alignment increased by 0.93° in varus orientation. The model explained 86% of the variability. CT demonstrates excellent reliability for assessing coronal lower limb alignment compared to EOS in osteoarthritic knees. This supports the routine use of CT to plan TKA without further weight bearing imaging in routine cases


The Bone & Joint Journal
Vol. 103-B, Issue 6 | Pages 1063 - 1069
1 Jun 2021
Amundsen A Brorson S Olsen BS Rasmussen JV

Aims. There is no consensus on the treatment of proximal humeral fractures. Hemiarthroplasty has been widely used in patients when non-surgical treatment is not possible. There is, despite extensive use, limited information about the long-term outcome. Our primary aim was to report ten-year patient-reported outcome after hemiarthroplasty for acute proximal humeral fractures. The secondary aims were to report the cumulative revision rate and risk factors for an inferior patient-reported outcome. Methods. We obtained data on 1,371 hemiarthroplasties for acute proximal humeral fractures from the Danish Shoulder Arthroplasty Registry between 2006 and 2010. Of these, 549 patients (40%) were alive and available for follow-up. The Western Ontario Osteoarthritis of the Shoulder (WOOS) questionnaire was sent to all patients at nine to 14 years after primary surgery. Revision rates were calculated using the Kaplan-Meier method. Risk factors for an inferior WOOS score were analyzed using the linear regression model. Results. Mean age at surgery was 67 years (24 to 90) and 445 (81%) patients were female. A complete questionnaire was returned by 364 (66%) patients at a mean follow-up of 10.6 years (8.8 to 13.8). Mean WOOS score was 64 (4.3 to 100.0). There was no correlation between WOOS scores and age, sex, arthroplasty brand, or year of surgery. The 14-year cumulative revision rate was 5.7% (confidence interval 4.1 to 7.2). Patients aged younger than 55 years and patients aged between 55 to 74 years had 5.6-times (2.0 to 9.3) and 4.3-times (1.9 to 16.7) higher risk of revision than patients aged older than 75 years, respectively. Conclusion. This is the largest long-term follow-up study of acute proximal humeral fractures treated with hemiarthroplasty. We found a low revision rate and an acceptable ten-year patient-reported outcome. The patient-reported outcome should be interpreted with caution as we have no information about the patients who died or did not return a complete WOOS score. The long-term outcome and revision rate suggest that hemiarthroplasty offers a valid alternative when non-surgical treatment is not possible. Cite this article: Bone Joint J 2021;103-B(6):1063–1069


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_8 | Pages 105 - 105
11 Apr 2023
Buser Z Yoon S Meisel H Hauri D Hsieh P Wang J Corluka S
Full Access

Mental disorders in particular depression and anxiety have been reported to be prevalent among patients with spinal pathologies. Goal of the current study was to analyze the relationship of Zung pre- and post-op score to other PROs and length of stay. Secondary outcomes included revision surgery and post-operative infections. Data from the international multicenter prospective spine degenerative surgery data repository, DegenPRO v1.1 (AO Spine Knowledge Forum Degenerative) were utilized. Patients undergoing cervical or lumbar procedure were included. Patient's demographics, Charlson Comorbidity Index, surgical information, Zung score, NDI, pain related PROs and EQ-5D, and complications at surgery and at various post-op time periods. Except for hospital duration, data were analyzed, using multivariable mixed linear models. A robust linear regression model was used to assess the association between Zung score and hospital duration. All models were adjusted for gender and age. 42 patients had Zung score administered. Among those patients 22 (52%) were within normal range, 18 (43%) were mildly and 2 (5%) severely depressed. 62% of the patients had a lumbar pathology with fusion procedures being the most common. Median EQ-5D (3L) score at surgery was significantly higher (0.7, IQR: 0.4-0.7) for patients within normal range than for those with mild (0.4, IGR: 0.3-0.7) or severe depression (0.3, IQR: 0.3-0.3, p-value: 0.05). Compared to patients within normal Zung range, mixed models, indicated lower EQ-5D (3L) score values and higher values for neck and arm pain at surgery with both PROs and EQ-5D (3L) improving in patients with depression over the follow-up time. No association was found between Zung score and hospital length of stay. The initial analysis showed that 43% of the patients were mildly depressed and mainly male patients. Zung score was correlated with post-operative improvements in EQ-5D and arm and neck pain PROs


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_3 | Pages 59 - 59
23 Feb 2023
Rahardja R Mehmood A Coleman B Munro J Young S
Full Access

The optimal timing of when to perform manipulation under anesthesia (MUA) for stiffness following total knee arthroplasty (TKA) is unclear. This study aimed to identify the risk factors for MUA following primary TKA and whether performing an “early” MUA within 3 months results in a greater improvement in range of motion. Primary TKAs performed between January 2013 and December 2018 at three tertiary New Zealand hospitals were reviewed. International Classification of Diseases discharge coding was used to identify patients who underwent an MUA. Multivariate Cox regression was performed to identify patient and surgical risk factors for MUA. Pre- and post-MUA knee flexion angles were identified through manual review of operation notes. Multivariate linear regression was performed to compare the mean flexion angles pre- and post-MUA, as well as the mean gain in flexion, between patients undergoing “early” (<3 months) versus “late” MUA (>3 months). 7386 primary TKAs were analyzed in which 131 underwent subsequent MUA (1.8%). Patients aged <65 years were two times more likely to undergo MUA compared to patients aged ≥65 years (2.5% versus 1.3%, adjusted hazard ratio = 2.1, p<0.001). Gender, body mass index, patient comorbidities or a history of cancer were not associated with the risk of MUA. There was no difference in the final post-MUA flexion angle between patients who underwent early versus late MUA (104.7 versus 104.1 degrees, p = 0.819). However, patients who underwent early MUA had poorer pre-MUA flexion (72.3 versus 79.6 degrees, p = 0.012), and subsequently had a greater overall gain in flexion compared to patients who underwent late MUA (mean gain 33.1 versus 24.3 degrees, p<0.001). Younger age was the only patient risk factor for MUA. A greater overall gain in flexion was achieved in patients who underwent early MUA within 3 months


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_12 | Pages 61 - 61
23 Jun 2023
Petrie JR Nepple JJ Thapa S Schoenecker PL Clohisy JC
Full Access

The periacetabular osteotomy (PAO) is a well-described procedure for symptomatic acetabular dysplasia. For severe acetabular deformities, the efficacy of acetabular reorientation remains controversial and the literature on mid to long-term outcomes is limited. The purpose of this study was to analyze average 10-year clinical and radiographic results of the PAO for severe acetabular dysplasia. We retrospectively analyzed a consecutive series of patients undergoing PAO for severe acetabular dysplasia as defined by LCEA < 5˚. Patient demographics, radiographic measurements, modified Harris Hip score (MHHS), UCLA activity, SF-12, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were assessed. Sixty-eight patients (82 hips; 54 females) with an average age 20.7 and BMI of 24.4 kg/m2 were included. Mean follow-up was follow up was 10.3 years. . The LCEA and ACEA improved a mean of 32.8˚ (8.4˚ to 24.4˚, p<0.0001) and 31.6˚ (−4.9˚ to 26.7˚, p< 0.0001), respectively. MHHS improved an average of 17.5 points (64.6 to 82.3, p<0.0001), WOMAC Pain subscore improved an average of 21.1 points (65.7 to 85.0, p = 0.004), and SF-12 physical improved 11.8 points (from 40.3 to 50.6, p = 0.006). Activity improved as indicated by a 1.5-point increase in the UCLA Activity score (6.4 to 7.9, p=0.005). Six hips (9.1%) converted to THA at average 6.8 years post-PAO. Kaplan-Meier survival analysis with THA as the endpoint was 92% at 15 years (95% confidence interval [CI] (81%–96%). Multivariable linear regression analysis revealed concurrent osteochondroplasty was associated with a decreased risk of PAO failure. PAO is an effective treatment for severe acetabular dysplasia. At average 10.3 years, clinical and radiographic outcomes demonstrate pain relief, improved hip function, and major deformity correction. We observed minimal clinical deterioration over time


The Bone & Joint Journal
Vol. 103-B, Issue 5 | Pages 964 - 970
1 May 2021
Ling DI Schneider B Ode G Lai EY Gulotta LV

Aims. To investigate the impact of the Charlson and Elixhauser comorbidity indices on patient-reported outcomes measures (PROMs) following shoulder arthroplasty. Methods. Patients undergoing total shoulder arthroplasty (TSA), reverse shoulder arthroplasty (RSA), or hemiarthroplasty (HA) from 2016 to 2018 were identified, along with the Charlson and Elixhauser comorbidities listed as their secondary diagnoses in the electronic medical records. Patients were matched to our institution’s registry to obtain their PROMs, including shoulder-specific (American Shoulder and Elbow Society (ASES) and Shoulder Activity Scale (SAS)) and general health scales (12-Item Short Form Survey (SF-12) and Patient-Reported Outcomes Measurement Information System-Pain Interference). Linear regression models adjusting for age and sex were used to evaluate the association between increasing number of comorbidities and PROM scores. A total of 1,817 shoulder arthroplasties were performed: 1,017 (56%) TSA, 726 (40%) RSA, and 74 (4%) HA. The mean age was 67 years (SD 10), and 936 (52%) of the patients were female. Results. The most common comorbidities were obesity (1,256, 69%) and hypertension (990, 55%). Patients with more comorbidities had lower ASES and SAS scores at baseline (p < 0.001). Elixhauser comorbidities continued to negatively impact ASES and SAS scores at one year (p = 0.002) and two-year follow-up (p = 0.002). Patients with more comorbidities reported greater pain interference on PROMIS at baseline (p = 0.007), but not at two years. Higher number of Charlson comorbidities were associated with lower scores on the SF-12 mental component at baseline (p < 0.001) and two years (p = 0.020). Higher number of Elixhauser comorbidities were associated with lower SF-12 physical component scores at baseline (p < 0.001) and two years (p = 0.004). Conclusion. Higher number of comorbidities was associated with lower baseline scores and worse outcomes on both shoulder-specific and general health PROMs. The presence of specific comorbidities may be used during shared decision-making to manage expectations for patients undergoing shoulder arthroplasty. Cite this article: Bone Joint J 2021;103-B(5):964–970


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_2 | Pages 49 - 49
1 Mar 2021
Dixon A Wareen J Mengoni M Wilcox R
Full Access

Abstract. Objectives. Develop a methodology to assess the long term mechanical behavior of intervertebral discs by utilizing novel sequential state testing. Methods. Bovine functional spinal units were sequentially mechanically tested in (1) native (n=8), (2) degenerated (n=4), and (3) treated states (n=4). At stage (2), artificial degeneration was created using rapid enzymatic degeneration, followed by a 24 hour hold period under static load at 42°C. At stage (3), nucleus augmentation treatments were injected with a hydrogel or a ‘sham’ (water, chondroitin sulfate) injection. The mechanical protocol employed applied a static load hold period followed by cyclic compressive loading between ∼350 and 750 N at 1 Hz. 1000 cycles were applied at each stage, and the final test on each specimen was extended up to 20000 cycles. To verify if test time can be reduced, functions were fitted using stiffness data up to 100, 1000, 2500, 5000, 10000 and 20000 cycles. Linear regression for the native specimens comparing the stiffness at various cycles to the stiffness at 20000 cycles was completed. Results. Independent of the disc state, as the number of cycles increased, the hysteresis decreased and the stiffness increased. The degenerated specimen stiffness was greater than the healthy and treated stiffness and the degenerate hysteresis loops were smaller. A mathematical model was found to successfully predict the high cycle behaviour of the disc reaching a root mean squared (RMS) error below 10% when using 5000 or more cycles. The linear regression gave a RMS error below 7.5% at 1000 cycles. Conclusions. A method was developed to consistently determine intervertebral disc mechanics through sequential testing. A shortened cyclic testing period was shown to be viable as a method to reduce preliminary test time for novel hydrogels, compared to currently literature. The methodology permits rapid preliminary assessment of intervertebral disc mechanics and treatments. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_2 | Pages 23 - 23
1 Mar 2021
Howgate D Oliver M Stebbins J Garfjeld-Roberts P Kendrick B Rees J Taylor S
Full Access

Abstract. Objectives. Accurate orientation of the acetabular component during a total hip replacement is critical for optimising patient function, increasing the longevity of components, and reducing the risk of complications. This study aimed to determine the validity of a novel VR platform (AescularVR) in assessing acetabular component orientation in a simulated model used in surgical training. Methods. The AescularVR platform was developed using the HTC Vive® VR system hardware, including wireless trackers attached to the surgical instruments and pelvic sawbone. Following calibration, data on the relative position of both trackers are used to determine the acetabular cup orientation (version and inclination). The acetabular cup was manually implanted across a range of orientations representative of those expected intra-operatively. Simultaneous readings from the Vicon® optical motion capture system were used as the ‘gold standard’ for comparison. Correlation and agreement between these two methods was determined using Bland-Altman plots, Pearson's correlation co-efficient, and linear regression modelling. Results. A total of 55 separate orientation readings were obtained. The mean average difference in acetabular cup version and inclination between the Vicon and VR systems was 3.4° (95% CI: −3–9.9°), and −0.005° (95% CI: −4.5–4.5°) respectively. Strong positive correlations were demonstrated between the Vicon and VR systems in both acetabular cup version (Pearson's R = 0.92, 99% CI: 0.84–0.96, p<0.001), and inclination (Pearson's R = 0.94, 99% CI: 0.88–0.97, p<0.001). Using linear regression modelling, the adjusted R. 2. for acetabular version was 0.84, and 0.88 for acetabular inclination. Conclusion. The results of this study indicate that the AescularVR platform is highly accurate and reliable in determining acetabular component orientation in a simulated environment. The AescularVR platform is an adaptable tracking system, which may be modified for use in a range of simulated surgical training and educational purposes, particularly in orthopaedic surgery. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_2 | Pages 103 - 103
10 Feb 2023
Petterwood J Sullivan J Coffey S McMahon S Wakelin E Plaskos C Orsi A
Full Access

Preoperative ligament laxity can be characterized intraoperatively using digital robotic tensioners. Understanding how preoperative knee joint laxity affects preoperative and early post-operative patient reported outcomes (PROMs) may aid surgeons in tailoring intra-operative balance and laxity to optimize outcomes for specific patients. This study aims to determine if preoperative ligament laxity is associated with PROMs, and if laxity thresholds impact PROMs during early post-operative recovery. 106 patients were retrospectively reviewed. BMI was 31±7kg/m. 2. Mean age was 67±8 years. 69% were female. Medial and lateral knee joint laxity was measured intraoperatively using a digital robotic ligament tensioning device after a preliminary tibial resection. Linear regressions between laxity and KOOS12-function were performed in extension (10°), midflexion (45°), and flexion (90°) at preoperative, 6-week, and 3-month time points. Patients were separated into two laxity groups: ≥7 mm laxity and <7 mm laxity. Student's t-tests determined significant differences between laxity groups for KOOS12-function scores at all time points. Correlations were found between preoperative KOOS12-function and medial laxity in midflexion (p<0.001) and flexion (p<0.01). Patients with <7 mm of medial laxity had greater preoperative KOOS12-function scores compared to patients with ≥7 mm of medial laxity in extension (46.8±18.2 vs. 29.5±15.6, p<0.05), midflexion (48.4±17.8 vs. 32±16.1, p<0.001), and flexion (47.7±18.3 vs. 32.6±14.7, p<0.01). No differences in KOOS12-function scores were observed between medial laxity groups at 6-weeks or 3-months. All knees had <5 mm of medial laxity postoperatively. No correlations were found between lateral laxity and KOOS12-function. Patients with preoperative medial laxity ≥7 mm had lower preoperative PROMs scores compared to patients with <7 mm of medial laxity. No differences in PROMs were observed between laxity groups at 6 weeks or 3 months. Patients with excessive preoperative joint laxity achieve similar PROMs scores to those without excessive laxity after undergoing gap balancing TKA


Abstract. Introduction. Cementless fixation of Oxford Unicompartmental Knee Replacements (UKRs) is an alternative to cemented fixation, however, it is unknown whether cementless fixation is as good long-term. This study aimed to compare primary and long-term fixation of cemented and cementless Oxford UKRs using radiostereometric analysis (RSA). Methodology. Twenty-nine patients were randomised to receive cemented or cementless Oxford UKRs and followed for ten years. Differences in primary fixation and long-term fixation of the tibial components (inferred from 0/3/6-month and 6-month/1-year/2-year/5-year/10-year migration, respectively) were analysed using RSA and radiolucencies were assessed on radiographs. Migration rates were determined by linear regression and clinical outcomes measured using the Oxford Knee Score (OKS). Results. Preliminary analysis of Maximum Total Point Motion (MTPM) indicated cementless tibial components undergo significantly more migration than cemented components during the first 6 months (1.6mm/year, SD=0.92 versus 1.3mm/year, SD=1.1, p<0.001). Cementless migration was predominantly subsidence inferiorly (Mean=0.51mm/year, SD=0.29, p<0.001) and posteriorly (0.13mm/year, SD=0.21, p=0.03). Contrastingly, from 6 months to 10 years cemented components migrated significantly (MTPM=0.039mm/year, SD=0.11, p=0.04) whereas cementless components did not (MTPM=0.002mm/year, SD=0.02, p=0.744). Radiolucent lines occurred more frequently below cemented (10/13) than cementless (4/16) tibial components, but radiolucencies did not correlate with differences in migration or OKS. There was no significant difference in OKS between cemented and cementless. Conclusion. These results suggest that cementless tibial components migrate more than cemented before achieving primary fixation. However, long-term fixation of cementless tibial components appears to be as good, if not better, than cemented with the benefit of fewer radiolucent lines


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_14 | Pages 34 - 34
1 Dec 2022
Cavazzoni G Cristofolini L Barbanti-Bròdano G Dall'Ara E Palanca M
Full Access

Bone metastases radiographically appear as regions with high (i.e. blastic metastases) or low (i.e. lytic metastases) bone mineral density. The clinical assessment of metastatic features is based on computed tomography (CT) but it is still unclear if the actual size of the metastases can be accurately detected from the CT images and if the microstructure in regions surrounding the metastases is altered (Nägele et al., 2004, Calc Tiss Int). This study aims to evaluate (i) the capability of the CT in evaluating the metastases size and (ii) if metastases affect the bone microstructure around them. Ten spine segments consisted of a vertebra with lytic or mixed metastases and an adjacent control (radiologically healthy) were obtained through an ethically approved donation program. The specimens were scanned with a clinical CT (AquilionOne, Toshiba: slice thickness:1mm, in-plane resolution:0.45mm) to assess clinical metastatic features and a micro-CT (VivaCT80, Scanco, isotropic voxel size:0.039mm) to evaluate the detailed microstructure. The volume of the metastases was measured from both CT and micro-CT images (Palanca et al., 2021, Bone) and compared with a linear regression. The microstructural alteration around the metastases was evaluated in the volume of interest (VOI) defined in the micro-CT images as the volume of the vertebral body excluding the metastases. Three 3D microstructural parameters were calculated in the VOI (CTAn, Bruker SkyScan): Bone Volume Fraction (BV/TV), Trabecular Thickness (Tb.Th.), Trabecular Spacing (Tb.Sp.). Medians of each parameter were compared (Kruskal-Wallis, p=0.05). One specimen was excluded as it was not possible to define the size of the metastases in the CT scans. A strong correlation between the volume obtained from the CT and micro-CT images was found (R2=0.91, Slope=0.97, Intercept=2.55, RMSE=5.7%, MaxError=13.12%). The differences in BV/TV, Tb.Th. and Tb.Sp. among vertebrae with lytic and mixed metastases and control vertebrae were not statistically significant (p-value>0.6). Similar median values of BV/TV were found in vertebrae with lytic (13.2±2.4%) and mixed (12.8±9.8%) metastases, and in controls (13.0±10.1%). The median Tb.Th. was 176±18 ∓m, 179±43 ∓m and 167±91 ∓m in vertebrae with lytic and mixed metastases and control vertebrae, respectively. The median Tb. Sp. was 846±26 ∓m, 849±286 ∓m and 880±116 ∓m in vertebrae with lytic and mixed metastases and control vertebrae, respectively. In conclusion, the size of vertebral metastases can be accurately assess using CT images. The 3D microstructural parameters measured were comparable with those reported in the literature for healthy vertebrae (Nägele et al., 2004, Calc Tiss Int, Sone et al., 2004, Bone) and showed how the microstructure of the bone tissue surrounding the lesion is not altered by the metastases


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 107 - 107
1 Dec 2022
Schneider P You D Dodd A Duffy P Martin R Skeith L Soo A Korley R
Full Access

Thrombelastography (TEG) is a point-of-care tool that can measure clot formation and breakdown using a whole blood sample. We have previously used serial TEG analysis to define hypercoagulability and increased venous thromboembolism (VTE) risk following a major fracture requiring surgical treatment. Additionally, we have used serial TEG analysis to quantify the prolonged hypercoagulable state and increased VTE risk that ensues following a hip fracture. Recently developed cartridge-based platelet mapping (PLM) using TEG analysis can be used to activate platelets at either the adenosine diphosphate (ADP) receptor or at the Thromboxane A2 (AA) receptor, in order to evaluate clot strength when platelets are activated only through those specific receptors. This study aim was to evaluate platelet contribution to hypercoagulability, in order to identify potential therapeutic targets for VTE prevention. We hypothesized that there would be a platelet-predominant contribution to hypercoagulability following a hip fracture. Patients aged 50 years or older with a hip fracture treated surgically were enrolled in this prospective cohort study. Exclusion criteria were: prior history of VTE, active malignancy, or pre-injury therapeutic dose anticoagulation. Serial TEG and PLM analyses were performed at admission, post-operative day (POD) 1, 3, 5, 7 and at 2-, 4-, 6- and 12-weeks post-operatively. All patients received thromboprophylaxis with low molecular weight heparin (LMWH) for 28 days post-operatively. Hypercoagulability was defined as maximal amplitude (MA; a measure of clot strength) over 65mm based on TEG analysis. Independent samples t-tests were used to compare MA values with this previously established threshold and a mixed effects linear regression model was used to compare MA values over time. Independent samples t-tests and Chi-sqaured analyses were used to compare between the surgical fixation and arthroplasty groups. Forty-six patients with an acute hip fracture were included, with a mean age of 77.1 (SD = 10.6) years, with 61% (N=11) being female. Twenty-six were treated with arthroplasty (56.5%), while the remainder underwent surgical fixation of their hip fractures. TEG analysis demonstrated post-operative hypercoagulability (mean MA over 65mm) at all follow-up timepoints until 12-weeks. PLM identified a platelet-mediated hypercoagulable state based on elevated ADP-MA and AA-MA, with more pronounced platelet contribution demonstrated by the AA pathway. Patients treated with arthroplasty had significantly increased AA-MA compared with ADP-MA at POD 3 and at the 12-week follow-up. Thrombelastography can be used to identify hypercoagulability and increased risk for VTE following a hip fracture. Platelet mapping analysis from this pilot study suggests a platelet-mediated hypercoagulable state that may benefit from thromboprophylaxis using an anti-platelet agent that specifically targets the AA platelet activation pathway, such as acetylsalicylic acid (ASA). This research also supports differences in hypercoagulability between patients treated with arthroplasty compared to those who undergo fracture fixation


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_1 | Pages 22 - 22
1 Feb 2021
Kamath A Acuna A Jella T Cwalina T Samuel L
Full Access

Introduction. Innovations in orthopaedic technology and infrastructure growth often require significant funding. Although an increasing trend has been observed for third-party investments into medical startups and physician practices, no study has examined the role of this funding in orthopaedics, including the influence of venture capital (VC). Therefore, this study analyzed trends in VC investments related to the field of orthopaedic surgery, as well as the characteristics of companies receiving said investments. Methods. Venture capital investments into orthopaedic-related businesses were reviewed from 2000–2019 using Capital IQ, a proprietary market intelligence platform documenting financial transactions. The dataset was initially filtered to include healthcare-related venture capital transactions pertaining to the field of orthopaedic surgery. The final list of VC investments and their corresponding businesses were categorized by transaction year, amount (in USD), and orthopaedic subspecialty. The number and sum of VC investments was calculated both annually and cumulatively across the entire study period. Linear regression was used for trend analysis within two distinct, decade-long timeframes (2000–2009 and 2010–2019) and one-way analysis of variance was used to assess differences across orthopaedic subspecialties. Results. Over the course of two decades, 672 VC investments were made into orthopaedic-related businesses, representing a total of $3.5 billion. Both the number and dollar value of transactions were greater in the second decade (2010–19) (233, $1.9 billion), compared to the first decade (439, $1.6 billion). Linear regression revealed significant trends in both the quantity and dollar amount of VC transactions within the decade from 2000–09 (p = 0.0002 and p = 0.0143, respectively) but no such trend in the latter decade (Figure 1A-B, Figure 2A-B). Throughout both decades studied, the largest and most frequent VC investments took place within Spine and Adult Reconstruction (Figure 3). One-way analysis of variance revealed significant differences in the annual frequency and amount of investment across orthopaedic subspecialties (p < 0.001 and p < 0.001, respectively). Discussion and Conclusion. The present data suggest that an initially rising trend in VC investment in orthopaedic-related businesses may have plateaued over the past decade. These findings may have important implications for continued investment into orthopaedic innovations and collaboration between the surgical community and private sector, as well as the perceived profitability of orthopaedic industries by third-party interests. For any figures or tables, please contact the authors directly


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_16 | Pages 7 - 7
17 Nov 2023
Hayward S Gheduzzi S Keogh P Miles T
Full Access

Abstract. Objectives. Spinal stiffness and flexibility terms are typically evaluated from linear regression of experimental data and are then assembled into 36-element matrices. Summarising in vitro test results in this manner is quick, computationally cheap and has the distinct advantage of outputting simple characteristic values which make it easy to compare results. However, this method disregards many important experimental features such as stiffening effects, neutral and elastic zones magnitudes, extent of asymmetry and energy dissipation (hysteresis). Alternatives to the linear least squares method include polynomials, separation of the load-displacement behaviour into the neutral and elastic zones using various deterministic methods and variations on the double sigmoid and Boltzmann curve fits. While all these methods have their advantages, none provide a comprehensive and complete characterisation of the load-displacement behaviour of spine specimens. In 1991, Panjabi demonstrated that the flexion-extension and mediolateral bending behaviour of functional spinal units could be approximated using the viscoelastic model consisting of a nonlinear spring in series with a linear Kelvin element. Nowadays viscoelastic models are mainly used to describe creep and stress relaxation, rather than for cyclic loading. The aim of this study was to conclusively prove the viscoelastic nature of spinal behaviour subject to cyclic loading. Being able to describe the behaviour of spine specimens using springs and dampers would yield characterising coefficients with recognisable physical meaning, thus providing an advantage over existing techniques. Methods. Six porcine isolated spinal disc specimens (ISDs) were tested under position and load control. Visual inspection of the load-displacement graphs from which the principal terms of the stiffness and flexibility matrices are derived suggest that the load-displacement behaviour could be idealised by a nonlinear spring system with damping. It was hypothesised that the contributions arising from non-linear spring-like behaviour and damping could be separated for each of the principal load-displacement graphs. Results. The principal elements from position and load control tests were plotted with load on the vertical axis and displacement on the horizontal axis, and a polynomial representing spring force was fitted to the data. This polynomial was subtracted from the experimental data. The remainder - representing damping force - was plotted against displacement and velocity and compared to idealised plots for different types of damping behaviour. Applying this reasoning to the six principal load-displacement plots obtained from stiffness and flexibility tests revealed that four of six exhibit behaviour which is a combination of a nonlinear hardening spring and viscous damper. However, for flexion-extension and mediolateral bending, the damping behaviour is more akin to coulomb damping with viscous influences, characterised by a steep central linear region and near horizontal regions at the extremes. These trends were common amongst all six specimens within the study sample size. Conclusions. The unique approach described here has allowed the characterisation of the load-displacement behaviour of ISDs in terms of characteristic mass-spring-damper systems. This is an important development which allows experimental findings to be framed in terms of mechanical contributions to a given load-displacement behaviour. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_14 | Pages 35 - 35
1 Dec 2022
Montanari S Griffoni C Cristofolini L Brodano GB
Full Access

Mechanical failure of spine posterior fixation in the lumbar region Is suspected to occur more frequently when the sagittal balance is not properly restored. While failures at the proximal extremity have been studied in the literature, the lumbar distal junctional pathology has received less attention. The aim of this work was to investigate if the spinopelvic parameters, which characterize the sagittal balance, could predict the mechanical failure of the posterior fixation in the distal lumbar region. All the spine surgeries performed in 2017-2019 at Rizzoli Institute were retrospectively analysed to extract all cases of lumbar distal junctional pathology. All the revision surgeries performed due to the pedicle screws pull-out, or the breakage of rods or screws, or the vertebral fracture, or the degenerative disc disease, in the distal extremity, were included in the junctional (JUNCT) group. A total of 83 cases were identified as JUNCT group. All the 241 fixation surgeries which to date have not failed were included in the control (CONTROL) group. Clinical data were extracted from both groups, and the main spinopelvic parameters were assessed from sagittal standing preoperative (pre-op) and postoperative (post-op) radiographs with the software Surgimap (Nemaris). In particular, pelvic incidence (PI), sagittal vertical axis (SVA), pelvic tilt (PT), T1 pelvic angle (TPA), sacral slope (SS) and lumbar lordosis (LL) have been measured. In JUNCT, the main failure cause was the screws pull-out (45%). Spine fixation with 7 or more levels were the most common in JUNCT (52%) in contrast to CONTROL (14%). In CONTROL, PT, TPA, SS and PI-LL were inside the recommended ranges of good sagittal balance. For these parameters, statistically significant differences were observed between pre-op and post-op (p<0.0001, p=0.01, p<0.0001, p=0.004, respectively, Wilcoxon test). In JUNCT, the spinopelvic parameters were out of the ranges of the good sagittal balance and the worsening of the balance was confirmed by the increase in PT, TPA, SVA, PI-LL and by the decrease of LL (p=0.002, p=0.003, p<0.0001, p=0.001, p=0.001, respectively, paired t-test) before the revision surgery. TPA (p=0.003, Kolmogorov-Smirnov test) and SS (p=0.03, unpaired t-test) differed significantly in pre-op between JUNCT and CONTROL. In post-op, PI-LL was significantly different between JUNCT and CONTROL (p=0.04, unpaired t-test). The regression model of PT vs PI was significantly different between JUNCT and CONTROL in pre-op (p=0.01, Z-test). These results showed that failure is most common in long fused segments, likely due to long lever arms leading to implant failure. If the sagittal balance is not properly restored, after the surgery the balance is expected to worsen, eventually leading to failure: this effect was confirmed by the worsening of all the spinopelvic parameters before the revision surgery in JUNCT. Conversely, a good sagittal balance seems to avoid a revision surgery, as it is visible is CONTROL. The mismatch PI-LL after the fixation seems to confirm a good sagittal balance and predict a good correction. The linear regression of PT vs PI suggests that the spine deformity and pelvic conformation could be a predictor for the failure after a fixation


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 3 - 3
1 Dec 2022
Hoit G Khan R Chahal J Whelan D
Full Access

Multiligament knee injuries (MLKI) are rare and life-altering injuries that remain difficult to treat clinically due to a paucity of evidence guiding surgical management and timing. The purpose of this study was to compare injury specific functional outcomes following early versus delayed surgical reconstruction in MLKI patients to help inform timing decisions in clinical practice. A retrospective analysis of prospectively collected data from patients with MLKIs at a single academic level 1-trauma center was conducted. Patients were eligible for inclusion if they had an MLKI, underwent reconstructive surgery either prior to 6wks from injury or between 12weeks and 2 years from injury, and had at least 12months of post-surgical follow-up. Patients with a vascular injury, open injuries or associated fractures were excluded. Study participants were stratified into early (<6wks from injury) and delayed surgical intervention (>12 weeks – 2 years from injury). The primary outcome was patient reported, injury specific, quality of life in the form of the Multiligament Quality of Life questionnaire (MLQOL) and its four domains (Physical Impairment, Emotional Impairment, Activity Limitations and Societal Involvement). We secondarily analyzed differences in the need for manipulation under anesthesia, and reoperation rates, as well as radiographic Kellgren Lawrence (KL) arthritis grades, knee laxity grading and range of motion at the most recent follow-up. A total of 131 patients met our inclusion criteria, all having had surgery between 2006 and 2019. There were 75 patients in the early group and 56 in the delayed group. The mean time to surgery was 17.6 ± 8.0 days in the early group versus 279 ± 146.5 days in the delayed. Mean postoperative follow-up was 58 months. There were no significant differences between early and delayed groups with respect to age (34 vs. 32.8 years), sex (77% vs 63% male), BMI (28.3 vs 29.7 kg/m. 2. ), or injury mechanism (p>0.05). The early surgery group was found to include more patients with lateral sided injuries (n=49 [65%] vs. n=23 [41%]; p=0.012), a higher severity of Schenck Classification (p=0.024) as well as nerve injuries at initial presentation (n=35 [49%] vs n=8 [18%]; p<0.001). Multivariable linear regression analyses of the four domains of the MLQOL did not demonstrate an independent association with early versus delayed surgery status (p>0.05), when controlling for age, sex, Schenck classification, medial versus lateral injury, and nerve injury status. In terms of our secondary outcomes, we found that the early group underwent significantly more manipulations under anesthesia compare with the delayed group (n=24, [32%] vs n=8 [14%], p=0.024). We did not identify a significant difference in physical examination laxity grades, range of motion, KL grade or reoperation rates between groups (p>0.05). We found no difference in patient reported outcomes between those who underwent early versus delayed surgery following MLKI reconstruction. In our secondary outcomes, we found significantly more patients in the early surgery group required a manipulation under anesthesia following surgery, which may indicate a propensity for arthrofibrosis after early MLKI reconstruction


The Bone & Joint Journal
Vol. 103-B, Issue 7 | Pages 1284 - 1291
1 Jul 2021
Carter TH Karunaratne BJ Oliver WM Murray IR White TO Reid JT Duckworth AD

Aims. Acute distal biceps tendon repair reduces fatigue-related pain and minimizes loss of supination of the forearm and strength of flexion of the elbow. We report the short- and long-term outcome following repair using fixation with a cortical button techqniue. Methods. Between October 2010 and July 2018, 102 patients with a mean age of 43 years (19 to 67), including 101 males, underwent distal biceps tendon repair less than six weeks after the injury, using cortical button fixation. The primary short-term outcome measure was the rate of complications. The primary long-term outcome measure was the abbreviated Disabilities of the Arm, Shoulder and Hand (QuickDASH) score. Secondary outcomes included the Oxford Elbow Score (OES), EuroQol five-dimension three-level score (EQ-5D-3L), satisfaction, and return to function. Results. Eight patients (7.8%) had a major complication and 34 (33.3%) had a minor complication. Major complications included re-rupture (n = 3; 2.9%), unrecovered nerve injury (n = 4; 3.9%), and surgery for heterotopic ossification (n = 1; 1.0%). Three patients (2.9%) overall required further surgery for a complication. Minor complications included neurapraxia (n = 27; 26.5%) and superficial infection (n = 7; 6.9%). A total of 33 nerve injuries occurred in 31 patients (30.4%). At a mean follow-up of five years (1 to 9.8) outcomes were available for 86 patients (84.3%). The median QuickDASH, OES, EQ-5D-3L, and satisfaction scores were 1.2 (IQR 0 to 5.1), 48 (IQR 46 to 48), 0.80 (IQR 0.72 to 1.0), and 100/100 (IQR 90 to 100), respectively. Most patients were able to return to work (81/83, 97.6%) and sport (51/62,82.3%). Unrecovered nerve injury was associated with an inferior outcome according to the QuickDASH (p = 0.005), OES (p = 0.004), EQ-5D-3L (p = 0.010), and satisfaction (p = 0.024). Multiple linear regression analysis identified an unrecovered nerve injury to be strongly associated with an inferior outcome according to the QuickDASH score (p < 0.001), along with infection (p < 0.001), although re-rupture (p = 0.440) and further surgery (p = 0.652) were not. Conclusion. Acute distal biceps tendon repair using cortical button fixation was found to result in excellent patient-reported outcomes and health-related quality of life. Although rare, unrecovered nerve injury adversely affects outcome. Cite this article: Bone Joint J 2021;103-B(7):1284–1291


The Bone & Joint Journal
Vol. 103-B, Issue 6 | Pages 1047 - 1054
1 Jun 2021
Keene DJ Knight R Bruce J Dutton SJ Tutton E Achten J Costa ML

Aims. To identify the prevalence of neuropathic pain after lower limb fracture surgery, assess associations with pain severity, quality of life and disability, and determine baseline predictors of chronic neuropathic pain at three and at six months post-injury. Methods. Secondary analysis of a UK multicentre randomized controlled trial (Wound Healing in Surgery for Trauma; WHiST) dataset including adults aged 16 years or over following surgery for lower limb major trauma. The trial recruited 1,547 participants from 24 trauma centres. Neuropathic pain was measured at three and six months using the Doleur Neuropathique Questionnaire (DN4); 701 participants provided a DN4 score at three months and 781 at six months. Overall, 933 participants provided DN4 for at least one time point. Physical disability (Disability Rating Index (DRI) 0 to 100) and health-related quality-of-life (EuroQol five-dimension five-level; EQ-5D-5L) were measured. Candidate predictors of neuropathic pain included sex, age, BMI, injury mechanism, concurrent injury, diabetes, smoking, alcohol, analgaesia use pre-injury, index surgery location, fixation type, Injury Severity Score, open injury, and wound care. Results. The median age of the participants was 51 years (interquartile range 35 to 64). At three and six months post-injury respectively, 32% (222/702) and 30% (234/787) had neuropathic pain, 56% (396/702) and 53% (413/787) had chronic pain without neuropathic characteristics, and the remainder were pain-free. Pain severity was higher among those with neuropathic pain. Linear regression analyses found that those with neuropathic pain at six months post-injury had more physical disability (DRI adjusted mean difference 11.49 (95% confidence interval (CI) 7.84 to 15.14; p < 0.001) and poorer quality of life (EQ-5D utility -0.15 (95% CI -0.19 to -0.11); p < 0.001) compared to those without neuropathic characteristics. Logistic regression identified that prognostic factors of younger age, current smoker, below knee fracture, concurrent injuries, and regular analgaesia pre-injury were associated with higher odds of post-injury neuropathic pain. Conclusion. Pain with neuropathic characteristics is common after lower limb fracture surgery and persists to six months post-injury. Persistent neuropathic pain is associated with substantially poorer recovery. Further attention to identify neuropathic pain post-lower limb injury, predicting patients at risk, and targeting interventions, is indicated. Cite this article: Bone Joint J 2021;103-B(6):1047–1054


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 4 - 4
1 Jul 2020
Salih S Grammatopoulos G Witt J
Full Access

Acetabular dysplasia (AD) can cause hip pain and early osteoarthritis. Lateral Centre Edge Angle (LCEA) and sourcil angle (AI) are plain radiographic measures of acetabular morphology, however there is little agreement as to what constitutes mild, moderate or severe dysplasia. This study aims to establish the correlation, if any, between two-dimensional (XR) and three-dimensional (CT) measurements of acetabular morphology and to establish the level of femoral head cover (CTFHC) for different levels of dysplasia. Methods. Governance board approved retrospective study. 353 PAOs performed by the senior author between January 2014 and December 2017 were included. Exclusion criteria were inadequate pre-operative CT imaging and/or plain radiographs, previous pelvic/hip surgery, acetabular retroversion, or femoral head asphericity. Of the remainder, 84 had 3D analysis by clinical graphics giving measurements for CTFHC, LCEA at 1100, 1200, 1300 and sourcil angle (AI). XRLCEA, AI, posterior wall index (PWI), and anterior wall index (AWI), were measured from supine AP pelvis radiographs. Pearson correlation coefficient, and mean CTFHC for stratified LCEAs were calculated. A linear regression model to predict CTFHC from XRLCEA was validated against these. Results. XRLCEA correlated very strongly with total femoral head coverage (Pearson=0.917, p<0.001). Mean CTFHC with XRLCEA between 15°-19.9° was 55% (range 51–59%). At 25° −29.9° mean CTFHC was 61%. There was a linear relation of CTFHC with XR LCEA such that CTFHC = 41.5 + 0.78(XRLCEA). This linear regression model predicted CTFHC 55% (95%CI 54–56%) for XRLCEA of 17.5°, and CTFHC 63% (95%CI 62–64%) for XRLCEA 27.5°. Conclusions. Currently an XRLCEA greater than 25° is considered normal. Previously reported normal values for CTFHC are 71–75%. This study demonstrates that those with acetabular parameters considered normal, may have low CTFHC and AD should be considered as a cause for their hip pain


The Bone & Joint Journal
Vol. 102-B, Issue 7 | Pages 959 - 964
1 Jul 2020
Malik AT Li M Khan SN Alexander JH Li D Scharschmidt TJ

Aims. Currently, the US Center for Medicaid and Medicare Services (CMS) has been testing bundled payments for revision total joint arthroplasty (TJA) through the Bundled Payment for Care Improvement (BPCI) programme. Under the BPCI, bundled payments for revision TJAs are defined on the basis of diagnosis-related groups (DRGs). However, these DRG-based bundled payment models may not be adequate to account appropriately for the varying case-complexity seen in revision TJAs. Methods. The 2008-2014 Medicare 5% Standard Analytical Files (SAF5) were used to identify patients undergoing revision TJA under DRG codes 466, 467, or 468. Generalized linear regression models were built to assess the independent marginal cost-impact of patient, procedural, and geographic characteristics on 90-day costs. Results. A total of 9,263 patients (DRG-466 = 838, DRG-467 = 4,573, and DRG-468 = 3,842) undergoing revision TJA from 2008 to 2014 were included in the study. Undergoing revision for a dislocation (+$1,221), periprosthetic fracture (+$4,454), and prosthetic joint infection (+$5,268) were associated with higher 90-day costs. Among comorbidities, malnutrition (+$10,927), chronic liver disease (+$3,894), congestive heart failure (+$3,292), anaemia (+$3,149), and coagulopathy (+$2,997) had the highest marginal cost-increase. The five US states with the highest 90-day costs were Alaska (+$14,751), Maryland (+$13,343), New York (+$7,428), Nevada (+$6,775), and California (+$6,731). Conclusion. Under the proposed DRG-based bundled payment methodology, surgeons would be reimbursed the same amount of money for revision TJAs, regardless of the indication (periprosthetic fracture, prosthetic joint infection, mechanical loosening) and/or patient complexity. Cite this article: Bone Joint J 2020;102-B(7):959–964


Aims. Torus fractures of the distal radius are the most common fractures in children. The NICE non-complex fracture guidelines recently concluded that bandaging was probably the optimal treatment for these injuries. However, across the UK current treatment varies widely due to a lack of evidence underpinning the guidelines. The Forearm Fracture Recovery in Children Evaluation (FORCE) trial evaluates the effect of a soft bandage and immediate discharge compared with rigid immobilization. Methods. FORCE is a multicentre, parallel group randomized controlled equivalence trial. The primary outcome is the Wong-Baker FACES pain score at three days after randomization and the primary analysis of this outcome will use a multivariate linear regression model to compare the two groups. Secondary outcomes are measured at one and seven days, and three and six-weeks post-randomization and include the Patient Reported Outcome Measurement Information System (PROMIS) upper extremity limb score, EuroQoL EQ-5D-Y, analgesia use, school absence, complications, and healthcare resource use. The planned statistical and health economic analyses for this trial are described here. The FORCE trial protocol has been published separately. Conclusion. This paper provides details of the planned analyses for this trial, and will reduce the risks of outcome reporting bias and data driven results. Cite this article: Bone Joint Open 2020;1-6:205–213


Bone & Joint Open
Vol. 2, Issue 1 | Pages 22 - 32
4 Jan 2021
Sprague S Heels-Ansdell D Bzovsky S Zdero R Bhandari M Swiontkowski M Tornetta P Sanders D Schemitsch E

Aims. Using tibial shaft fracture participants from a large, multicentre randomized controlled trial, we investigated if patient and surgical factors were associated with health-related quality of life (HRQoL) at one year post-surgery. Methods. The Study to Prospectively Evaluate Reamed Intramedullary Nails in Patients with Tibial Fractures (SPRINT) trial examined adults with an open or closed tibial shaft fracture who were treated with either reamed or unreamed intramedullary nails. HRQoL was assessed at hospital discharge (for pre-injury level) and at 12 months post-fracture using the Short Musculoskeletal Functional Assessment (SMFA) Dysfunction, SMFA Bother, 36-Item Short Form 36 (SF-36) Physical, and SF-36 Mental Component scores. We used multiple linear regression analysis to determine if baseline and surgical factors, as well as post-intervention procedures within one year of fracture, were associated with these HRQoL outcomes. Significance was set at p < 0.01. We hypothesize that, irrespective of the four measures used, prognosis is guided by both modifiable and non-modifiable factors and that patients do not return to their pre-injury level of function, nor HRQoL. Results. For patient and surgical factors, only pre-injury quality of life and isolated fracture showed a statistical effect on all four HRQoL outcomes, while high-energy injury mechanism, smoking, and race or ethnicity, demonstrated statistical significance for three of the four HRQoL outcomes. Patients who did not require reoperation in response to infection, the need for bone grafts, and/or the need for implant exchanges had statistically superior HRQoL outcomes than those who did require intervention within one year after initial tibial fracture nailing. Conclusion. We identified several baseline patient factors, surgical factors, and post-intervention procedures within one year after intramedullary nailing of a tibial shaft fracture that may influence a patient’s HRQoL. Cite this article: Bone Jt Open 2021;2(1):22–32


The Bone & Joint Journal
Vol. 103-B, Issue 3 | Pages 469 - 478
1 Mar 2021
Garland A Bülow E Lenguerrand E Blom A Wilkinson M Sayers A Rolfson O Hailer NP

Aims. To develop and externally validate a parsimonious statistical prediction model of 90-day mortality after elective total hip arthroplasty (THA), and to provide a web calculator for clinical usage. Methods. We included 53,099 patients with cemented THA due to osteoarthritis from the Swedish Hip Arthroplasty Registry for model derivation and internal validation, as well as 125,428 patients from England and Wales recorded in the National Joint Register for England, Wales, Northern Ireland, the Isle of Man, and the States of Guernsey (NJR) for external model validation. A model was developed using a bootstrap ranking procedure with a least absolute shrinkage and selection operator (LASSO) logistic regression model combined with piecewise linear regression. Discriminative ability was evaluated by the area under the receiver operating characteristic curve (AUC). Calibration belt plots were used to assess model calibration. Results. A main effects model combining age, sex, American Society for Anesthesiologists (ASA) class, the presence of cancer, diseases of the central nervous system, kidney disease, and diagnosed obesity had good discrimination, both internally (AUC = 0.78, 95% confidence interval (CI) 0.75 to 0.81) and externally (AUC = 0.75, 95% CI 0.73 to 0.76). This model was superior to traditional models based on the Charlson (AUC = 0.66, 95% CI 0.62 to 0.70) and Elixhauser (AUC = 0.64, 95% CI 0.59 to 0.68) comorbidity indices. The model was well calibrated for predicted probabilities up to 5%. Conclusion. We developed a parsimonious model that may facilitate individualized risk assessment prior to one of the most common surgical interventions. We have published a web calculator to aid clinical decision-making. Cite this article: Bone Joint J 2021;103-B(3):469–478


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_13 | Pages 145 - 145
1 Nov 2021
Papalia R Torre G Zampogna B Vorini F De Vincentis A Denaro V
Full Access

Introduction and Objective. Several factors contribute to the duration of the hospital stay in patients that undergo to total hip arthroplasty (THA), either subjective or perioperative. However, no definite evidence has been provided on the role of any of these factors on the hospitalization length. The aim of this retrospective investigation is to evaluate the correlation between several preoperative and perioperative factors and the length of hospital stay (LOS) in patients that underwent elective total hip arthroplasty. Materials and Methods. Medical records of patients that underwent THA since the beginning of 2016 to the end of 2018 were retrospectively screened. Demographics, comorbidities, renal function, whole blood count. and length of post-operative ward stay were retrieved. The association between clinical, biochemical and surgical factors and the length of hospital stay was explored by means of linear regression models. Results. A total of 743 subjects were included. Retrieved comorbidity included arterial hypertension (47%), dyslipidaemia (20%), chronic kidney disease (CKD) (12%) and diabetes mellitus (9%). The median length of post-operative hospital stay was 4 days (IQR: 2). Variables associated with linear increase of hospitalization length were the estimated Glomerular Filtration Rate (eGFR) (Beta −0.01, 95% CI −0.02, 0), CKD (Beta 0.82, 95% CI 0.29, 1.34), duration of surgery (Beta 0.69, 95% CI 0.44, 0.94). After correction for multiple confounders, the CKD (a-Beta 1.58 95%CI 0.00 – 3.22) and operation time (a-Beta 0.67, 95% CI 0.42, 0.92) were consistently associated with the outcome. Conclusions. Our analysis demonstrated a significant role played by the eGFR (as an index of renal function) in influencing the length of hospital stay


The Bone & Joint Journal
Vol. 102-B, Issue 1 | Pages 137 - 143
1 Jan 2020
Dias R Johnson NA Dias JJ

Aims. Carpal malalignment after a distal radial fracture occurs due to loss of volar tilt. Several studies have shown that this has an adverse influence on function. We aimed to investigate the magnitude of dorsal tilt that leads to carpal malalignment, whether reduction of dorsal tilt will correct carpal malalignment, and which measure of carpal malalignment is the most useful. Methods. Radiographs of patients with a distal radial fracture were prospectively collected and reviewed. Measurements of carpal malalignment were recorded on the initial radiograph, the radiograph following reduction of the fracture, and after a further interval. Linear regression modelling was used to assess the relationship between dorsal tilt and carpal malalignment. Receiver operating characteristic (ROC) analysis was used to identify which values of dorsal tilt led to carpal malalignment. Results. A total of 250 consecutive patients with 252 distal radial fractures were identified. All measures of carpal alignment were significantly associated with dorsal tilt at each timepoint. This relationship persisted after adjustment for age, sex, and the position of the wrist. Capitate shift consistently had the strongest relationship with dorsal tilt and was the only parameter that was not influenced by age or the position of the wrist. ROC curve analysis identified that abnormal capitate shift was seen with > 9° of dorsal tilt. Conclusion. Carpal malalignment is related to dorsal tilt following a distal radial fracture. Reducing the fracture and improving dorsal tilt will reduce carpal malalignment. Capitate shift is easy to assess visually, unrelated to age and sex, and appears to be the most useful measure of carpal malalignment. The aim during reduction of a distal radial fracture should be to realign the capitate with the axis of the radius and prevent carpal malalignment. Cite this article: Bone Joint J 2020;102-B(1):137–143


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_5 | Pages 6 - 6
1 Apr 2019
Knowles NK Langohr GDG Faieghi M Nelson A Ferreira L
Full Access

Introduction. Density-modulus relationships are often used to map the mechanical properties of bone based on CT- intensity in finite element models (FEMs). Although these relationships are thought to be site-specific, relationships developed for alternative anatomic locations are often used regardless of bone being modeled. Six relationships are commonly used in finite element studies of the shoulder; however, the accuracy of these relationships have yet to be compared. This study compares each of these six relationships ability to predict apparent strain energy density (SED. app. ) in trabecular bone cores from the glenoid. Methods. Quantitative-CT (QCT) (0.625 mm isotropic voxels), and µ-CT scans (0.032 mm isotropic voxels) were obtained for fourteen cadaveric scapulae (7 male, 7 female). Micro finite element models (µ-FEMs) were created from 98 virtual ‘cores’ using direct conversion to hexahedral elements. Two µ-FEM cases were considered: homogeneous tissue modulus of 20 GPa, and heterogeneous tissue modulus scaled by CT intensity of the µ-CT images (196 models). Each µ- FEM model was compressively loaded to 0.5% apparent strain and apparent strain energy density (SED. app. ) was calculated. Additionally, each of the six density-modulus relationships were used to map heterogeneous material properties to co- registered QCT-derived models (588 models in total). The loading and boundary conditions were replicated in the QCT-FEMs and the SED. app. was calculated and compared to the µ-FEM SED. app. To account for more samples than donors, restricted maximum likelihood estimation (REML) linear regression compared µ-FEM SED. app. and QCT-FEM SED. app. for each relationship. Results. When considering comparisons between QCT-FEMs and µ-FEMs with a homogeneous tissue modulus, near absolute statistical agreement (Y=X) was observed between the µ-FEMs and the QCT-FEMs using the Morgan et al. (2003) pooled relationship. Not surprisingly, due to the similarity between the two relationships, the Gupta & Dan (2004) and Carter and Hayes (1977) models showed near identical REML linear regression fit parameters. All relationships other than the Morgan et al. (2003) pooled relationship, greatly underestimated the µ-FEM apparent strain energy density (SED. app. ) when considering a homogeneous tissue modulus in the µ-FEMs. The same result with the pooled relationship did not hold true when heterogeneous tissue modulus was considered in the µ-FEMs. The Büchler et al., (2002) relationship most accurately predicted the SED. app. for this comparison. Interestingly, the Gupta & Dan (2004) and Carter and Hayes (1977) relationships again showed near identical REML linear regression fit parameters. DISCUSSION. This study compared six common density-modulus relationships used to map mechanical properties of bone in shoulder FE studies. It was found that when considering a homogeneous tissue modulus for µ-FEMs, relationships pooled from alternative anatomic locations may accurately predict the mechanical properties of glenoid trabecular bone. However, when considering a heterogeneous tissue modulus, this did not hold true. Further studies to determine if these relationships can be translated to whole bones may provide insight into the predictive capabilities of using pooled density-modulus equations in the mapping of mechanical properties in future FEMs of the shoulder


Bone & Joint Research
Vol. 10, Issue 3 | Pages 173 - 187
1 Mar 2021
Khury F Fuchs M Awan Malik H Leiprecht J Reichel H Faschingbauer M

Aims. To explore the clinical relevance of joint space width (JSW) narrowing on standardized-flexion (SF) radiographs in the assessment of cartilage degeneration in specific subregions seen on MRI sequences in knee osteoarthritis (OA) with neutral, valgus, and varus alignments, and potential planning of partial knee arthroplasty. Methods. We retrospectively reviewed 639 subjects, aged 45 to 79 years, in the Osteoarthritis Initiative (OAI) study, who had symptomatic knees with Kellgren and Lawrence grade 2 to 4. Knees were categorized as neutral, valgus, and varus knees by measuring hip-knee-angles on hip-knee-ankle radiographs. Femorotibial JSW was measured on posteroanterior SF radiographs using a special software. The femorotibial compartment was divided into 16 subregions, and MR-tomographic measurements of cartilage volume, thickness, and subchondral bone area were documented. Linear regression with adjustment for age, sex, body mass index, and Kellgren and Lawrence grade was used. Results. We studied 345 neutral, 87 valgus, and 207 varus knees. Radiological JSW narrowing was significantly (p < 0.01) associated with cartilage volume and thickness in medial femorotibial compartment in neutral (r = 0.78, odds ratio (OR) 2.33) and varus knees (r = 0.86, OR 1.92), and in lateral tibial subregions in valgus knees (r = 0.87, OR 3.71). A significant negative correlation was found between JSW narrowing and area of subchondral bone in external lateral tibial subregion in valgus knees (r = −0.65, p < 0.01) and in external medial tibial subregion in varus knees (r = −0.77, p < 0.01). No statistically significant correlation was found in anterior and posterior subregions. Conclusion. SF radiographs can be potentially used for initial detection of cartilage degeneration as assessed by MRI in medial and lateral but not in anterior or posterior subregions. Cite this article: Bone Joint Res 2021;10(3):173–187


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_10 | Pages 40 - 40
1 Aug 2021
Holleyman R Stamp G Board T Bankes M Khanduja V Malviya A
Full Access

Chondral hip injuries are common secondary to femoroacetabular impingement (FAI). Treatment with arthroscopic procedures including chondroplasty and microfracture is becoming increasingly common but literature is limited to case series at specialist centres. The aim of this study is to compare outcomes of arthroscopic acetabular chondral procedures using the NAHR dataset (UK) which represents the largest series to date. All adult Arthroscopies recorded in the NAHR from Jan 2012 were available for inclusion. Exclusions included significant arthritis and femoral, complex or revision chondral procedures. Patients completed iHOT-12 & EQ-5D Index pre-operatively, 6 and 12 months. Data was analysed using T-test/ANOVA for between group/within group for continuous variables, chi square test for categorical variables and linear regression model for multivariable analysis. 5,752 patients, 60% female. 27% Chondroplasty, 5% Microfracture, 68% no Chondral Procedure. Maximum acetabular Outerbridge classification 14% Grade 1, 15% Grade 2, 17% Grade 3, 8% Grade 4, 9% no damage, not recorded in 37%. Higher proportion of Cam impingement in association with chondral treatments and a larger proportion of patients with no impingement recorded in group with no chondral procedures. There was a significant improvement versus baseline for all groups in iHOT-12 and EQ-5D Index (p<0.0001) including Grade four Outerbridge. There was significantly greater improvement in pre-operative scores in the chondroplasty group compared to the microfracture group at 6 and 12 months (p<0.05). Following hip arthroscopy, patients with chondral procedures experienced improved outcome scores despite Outerbridge 4 chondral damage. Presence of cam lesions are more commonly associated with chondral treatments. Good outcomes were maintained up to 12 months for chondral procedures, regardless of age or impingement pathology however pincers improved less and patients over 40 years took longer to see improvement


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_11 | Pages 25 - 25
1 Sep 2021
Shah N Shafafy R Selvadurai S Benton A Herzog J Molloy S
Full Access

Introduction. Patients with metastatic spinal cord compression (MSCC) or unstable spinal lesions warrant early surgical consultation. In multiple myeloma, chemotherapy and radiotherapy have the potential to decompress the spinal canal effectively in the presence of epidural lesions. Mechanical stability conferred by bracing may potentiate intraosseous and extraosseous bone formation, thus increasing spinal stability. This study aims to review the role of non-operative management in myeloma patients with a high degree of spinal instability, in a specialist tertiary centre. Methods. Retrospective analysis of a prospectively collected database of 83 patients with unstable myelomatous lesions of the spine, defined by a Spinal Instability Neoplastic Score (SINS) of 13–18. Data collected include patient demographics, systemic treatment, neurological status, radiological presence of cord compression, most unstable vertebral level and presence of intraosseous and extraosseous bone formation. Post-treatment scores were calculated based on follow-up imaging which was carried out at 2 weeks for cord compression and 12 weeks for spinal instability. A paired t-test was used to identify any significant difference between pre- and post-treatment SINS and linear regression was used to assess the association between variables and the change in SINS. Results. A significant reduction in SINS was observed from a pre-treatment average score of 14 to a score of 9, following treatment for myeloma (p<0.001). A higher initial score and a younger age were associated with a larger overall reduction in SINS (p<0.001 and p=0.02 respectively). No single variable (bisphosphates, chemotherapy, radiotherapy and steroids) had a significant association with SINS reduction. 25 (30%) patients had spinal cord compression, all of which showed radiological resolution of cord compression at 2 weeks. No patients developed neurological deterioration during treatment and all patients had an improvement in their pain scores. 64 (77%) patients had evidence of intraosseous and/or extraosseous bone formation on their follow-up scan. Conclusion. Non-operative management in the form of bracing and systemic therapy is a safe and effective treatment for spinal instability and spinal cord compression in myeloma. Treatment of unstable myelomatous lesions of the spine with or without cord compression should not follow traditional guidelines for MSCC. The decision to adopt a non-operative approach in this cohort of patients should ideally be made in a tertiary centre with expertise in multiple myeloma and in a multidisciplinary setting


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_10 | Pages 33 - 33
1 Aug 2021
Holleyman R Sohatee M Bankes M Witt J Andrade T Board T McBryde C Conroy J Wilson M Khanduja V Malviya A
Full Access

Pelvic re-orientation osteotomy is a well-recognised treatment of young adults with developmental dysplasia of the hip (DDH). The most commonly used technique is the periacetabular osteotomy (PAO), however, some surgeons favour a triple osteotomy. These techniques can also be utilised for acetabular retroversion leading to FAI. Despite the published literature on these techniques, the authors note a scarcity of evidence looking at patient reported outcome measures (PROMs) for these procedures. This was a retrospective analysis of prospectively collected data utilising the UK NAHR. All patients who underwent pelvic osteotomy from January 2012 to November 2019 were identified from the NAHR database. Patients who consented to data collection received EQ-5D index and iHOT-12 questionnaires, with scores being collected pre-operatively and at 6, 12 and 24 months post-operatively. Nine hundred and eleven (911) patients were identified with twenty-seven (27) undergoing a triple osteotomy, the remaining patients underwent PAO. Mean age was 30.6 (15–56) years and 90% of patients were female. Seventy-nine (79) (8.7%) of patients had the procedure for acetabular retroversion leading to FAI. Statistical analysis, of all patients, showed significant improvement (p<0.001) for; iHOT-12 scores (+28 at 6-months, +33.8 at 12-months and +29.9 at 24-months). Similarly there was significant improvement (p<0.001) in EQ-5D index (+0.172 at 6-months, +0.187 at 12-months and +0.166 at 24-months). Pre-operatively, and at each follow-up time-period, raw scores were significantly better in the DDH group compared to the FAI group (p<0.05); however, the improvement in scores was similar for both groups. For both scoring measures, univariable and multivariable linear regression showed poorer pre-operative scores to be strongly significant predictors of greater post-operative improvement at 6 and 12 months (p<0.0001). Conclusions/Discussion. This study shows that pelvic osteotomy is a successful treatment for DDH and FAI, with the majority of patients achieving significant improvement in outcome scores which are maintained up to 24 months post-operatively. The patients with FAI have significantly reduced raw scores preoperatively and, perhaps, are functionally more limited


Bone & Joint Research
Vol. 9, Issue 8 | Pages 468 - 476
1 Aug 2020
Parsons NR Costa ML Achten J Griffin XL

Aims. To assess the variation in pre-fracture quality of life (QoL) within the UK hip fracture population, and quantify the nature and strength of associations between QoL and other routinely collected patient characteristics and treatment choices. Methods. The World Hip Trauma Evaluation (WHiTE) study, an observational cohort study of UK hip fracture patients, collects a range of routine data and a health-related QoL score (EuroQol five-dimension questionnaire (EQ-5D)). Pre-fracture QoL data are summarized and statistical models fitted to understand associations between QoL, patient characteristics, fracture types, and operations. Results. Fitting a multiple linear regression model indicated that 36.5% of the variance in pre-fracture EQ-5D scores was explained by routinely collected patient characteristics: sex (0.14%), age (0.17%), American Society of Anesthesiologists (ASA) score (0.73%), Abbreviated Mental Test Score (AMTS; 1.3%), pre-fracture mobility (11.2%), and EQ-5D respondent (participant, relative, or carer; 23.0%). There was considerable variation in pre-fracture EQ-5D scores between operations within fracture types. Participants with trochanteric fractures reported statistically significant but not clinically relevant lower pre-fracture QoL than those with intracapsular fractures. Participants with intracapsular fractures treated with internal fixation or total hip arthroplasty (THA) reported better QoL than those treated with hemiarthroplasty with the overall fittest group receiving THA. Conclusion. Pre-fracture QoL varies considerably between hip fracture patients; it is generally higher in younger than older patients, patients with better mobility, and those patients who live more independently. Pre-fracture QoL is significantly associated with a range of patient characteristics (e.g. age, mobility, residency). These data explain ~35% of the variation in QoL. Cite this article: Bone Joint Res 2020;9(8):468–476


The Bone & Joint Journal
Vol. 101-B, Issue 5 | Pages 573 - 581
1 May 2019
Almaguer AM Cichos KH McGwin Jr G Pearson JM Wilson B Ghanem ES

Aims. The purpose of this study was to compare outcomes of combined total joint arthroplasty (TJA) (total hip arthroplasty (THA) and total knee arthroplasty (TKA) performed during the same admission) versus bilateral THA, bilateral TKA, single THA, and single TKA. Combined TJAs performed on the same day were compared with those staged within the same admission episode. Patients and Methods. Data from the National (Nationwide) Inpatient Sample recorded between 2005 and 2014 were used for this retrospective cohort study. Postoperative in-hospital complications, total costs, and discharge destination were reviewed. Logistic and linear regression were used to perform the statistical analyses. p-values less than 0.05 were considered statistically significant. Results. Combined TJA was associated with increased risk of deep vein thrombosis, prosthetic joint infection, irrigation and debridement procedures, revision arthroplasty, length of stay (LOS), and in-hospital costs compared with bilateral THA, bilateral TKA, single THA, and single TKA. Combined TJA performed on separate days of the same admission showed no statistically significant differences when compared with same-day combined TJA, but trended towards decreased total costs and total complications despite increased LOS. Conclusion. Combined TJA is associated with increased in-hospital complications, LOS, and costs. We do not recommend performing combined TJA during the same hospital stay. Cite this article: Bone Joint J 2019;101-B:573–581


The Bone & Joint Journal
Vol. 103-B, Issue 6 Supple A | Pages 108 - 112
1 Jun 2021
Kahlenberg CA Krell EC Sculco TP Katz JN Nguyen JT Figgie MP Sculco PK

Aims. Many patients undergoing total knee arthroplasty (TKA) have severe osteoarthritis (OA) in both knees and may consider either simultaneous or staged bilateral TKA. The implications of simultaneous versus staged bilateral TKA for return to work are not well understood. We hypothesized that employed patients who underwent simultaneous bilateral TKA would have significantly fewer days missed from work compared with the sum of days missed from each operation for patients who underwent staged bilateral TKA. Methods. The prospective arthroplasty registry at the Hospital for Special Surgery was used. Baseline characteristics and patient-reported outcome scores were evaluated. We used a linear regression model, adjusting for potential confounding variables including age, sex, preoperative BMI, and type of work (sedentary, moderate, high activity, or strenuous), to analyze time lost from work after simultaneous compared with staged bilateral TKA. Results. We identified 152 employed patients who had undergone simultaneous bilateral TKA and 61 who had undergone staged bilateral TKA, and had completed the registry’s return to work questionnaire. The simultaneous group missed a mean of 46.2 days (SD 29.1) compared with the staged group who missed a mean total of 68.0 days of work (SD 46.1) when combining both operations. This difference was statistically significant (p < 0.001). In multivariate mixed regression analysis adjusted for age, sex, BMI, American Society of Anesthesiologists status, and type of work, the simultaneous group missed a mean of 16.9 (SD 5.7) fewer days of work compared with the staged group (95% confidence interval 5.8 to 28.1; p = 0.003). Conclusion. Employed patients undergoing simultaneous bilateral TKA missed a mean of 17 fewer days of work as a result of their surgical treatment and rehabilitation compared with those undergoing staged bilateral TKA. This information may be useful to surgeons counselling employed patients with bilateral OA of the knee who are considering surgical treatment. Cite this article: Bone Joint J 2021;103-B(6 Supple A):108–112


The Bone & Joint Journal
Vol. 101-B, Issue 7 | Pages 800 - 807
1 Jul 2019
Hampton SN Nakonezny PA Richard HM Wells JE

Aims. Psychological factors play a critical role in patient presentation, satisfaction, and outcomes. Pain catastrophizing, anxiety, and depression are important to consider, as they are associated with poorer outcomes and are potentially modifiable. The aim of this study was to assess the level of pain catastrophizing, anxiety, and depression in patients with a range of hip pathology and to evaluate their relationship with patient-reported psychosocial and functional outcome measures. Patients and Methods. Patients presenting to a tertiary-centre specialist hip clinic were prospectively evaluated for outcomes of pain catastrophizing, anxiety, and depression. Validated assessments were undertaken such as: the Pain Catastrophizing Scale (PCS), the Hospital Anxiety Depression Scale (HADS), and the 12-Item Short-Form Health Survey (SF-12). Patient characteristics and demographics were also recorded. Multiple linear regression modelling, with adaptive least absolute shrinkage and selection operator (LASSO) variable selection, was used for analysis. Results. A total of 328 patients were identified for inclusion, with diagnoses of hip dysplasia (DDH; n = 50), femoroacetabular impingement (FAI; n = 55), lateral trochanteric pain syndrome (LTP; n = 23), hip osteoarthrosis (OA; n = 184), and avascular necrosis of the hip (AVN; n = 16) with a mean age of 31.0 years (14 to 65), 38.5 years (18 to 64), 63.7 years (20 to 78), 63.5 years (18 to 91), and 39.4 years (18 to 71), respectively. The percentage of patients with abnormal levels of pain catastrophizing, anxiety, or depression was: 22.0%, 16.0%, and 12.0% for DDH, respectively; 9.1%, 10.9%, and 7.3% for FAI, respectively; 13.0%, 4.3%, and 4.3% for LTP, respectively; 21.7%, 11.4%, and 14.1% for OA, respectively; and 25.0%, 43.8%, and 6.3% for AVN, respectively. HADS Anxiety (HADSA) and Hip Disability Osteoarthritis Outcome Score Activities of Daily Living subscale (HOOS ADL) predicted the PCS total (adjusted R. 2. = 0.4599). Age, HADS Depression (HADSD), and PCS total predicted HADSA (adjusted R. 2. = 0.4985). Age, HADSA, patient’s percentage of perceived function, PCS total, and HOOS Quality of Life subscale (HOOS QOL) predicted HADSD (adjusted R. 2. = 0.5802). Conclusion. Patients with hip pathology may exhibit significant pain catastrophizing, anxiety, and depression. Identifying these factors and understanding the impact of psychosocial function could help improve patient treatment outcomes. Perioperative multidisciplinary assessment may be a beneficial part of comprehensive orthopaedic hip care. Cite this article: Bone Joint J 2019;101-B:800–807


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_1 | Pages 76 - 76
1 Feb 2020
Roche C Simovitch R Flurin P Wright T Zuckerman J Routman H
Full Access

Introduction. Machine learning is a relatively novel method to orthopaedics which can be used to evaluate complex associations and patterns in outcomes and healthcare data. The purpose of this study is to utilize 3 different supervised machine learning algorithms to evaluate outcomes from a multi-center international database of a single shoulder prosthesis to evaluate the accuracy of each model to predict post-operative outcomes of both aTSA and rTSA. Methods. Data from a multi-center international database consisting of 6485 patients who received primary total shoulder arthroplasty using a single shoulder prosthesis (Equinoxe, Exactech, Inc) were analyzed from 19,796 patient visits in this study. Specifically, demographic, comorbidity, implant type and implant size, surgical technique, pre-operative PROMs and ROM measures, post-operative PROMs and ROM measures, pre-operative and post-operative radiographic data, and also adverse event and complication data were obtained for 2367 primary aTSA patients from 8042 visits at an average follow-up of 22 months and 4118 primary rTSA from 11,754 visits at an average follow-up of 16 months were analyzed to create a predictive model using 3 different supervised machine learning techniques: 1) linear regression, 2) random forest, and 3) XGBoost. Each of these 3 different machine learning techniques evaluated the pre-operative parameters and created a predictive model which targeted the post-operative composite score, which was a 100 point score consisting of 50% post-operative composite outcome score (calculated from 33.3% ASES + 33.3% UCLA + 33.3% Constant) and 50% post-operative composite ROM score (calculated from S curves weighted by 70% active forward flexion + 15% internal rotation score + 15% active external rotation). 3 additional predictive models were created to control for the time required for patient improvement after surgery, to do this, each primary aTSA and primary rTSA cohort was subdivided to only include patient data follow-up visits >20 months after surgery, this yielded 1317 primary aTSA patients from 2962 visits at an average follow-up of 50 months and 1593 primary rTSA from 3144 visits at an average follow-up of 42 months. Each of these 6 predictive models were trained using a random selection of 80% of each cohort, then each model predicted the outcomes of the remaining 20% of the data based upon the demographic, comorbidity, implant type and implant size, surgical technique, pre-operative PROMs and ROM measures inputs of each 20% cohort. The error of all 6 predictive models was calculated from the root mean square error (RMSE) between the actual and predicted post-op composite score. The accuracy of each model was determined by subtracting the percent difference of each RMSE value from the average composite score associated with each cohort. Results. For all patient visits, the XGBoost decision tree algorithm was the most accurate model for both aTSA & rTSA patients, with an accuracy of ∼89.5% for both aTSA and rTSA. However for patients with 20+ month visits only, the random forest decision tree algorithm was the most accurate model for both aTSA & rTSA patients, with an accuracy of ∼89.5% for both aTSA and rTSA. The linear regression model was the least accurate predictive model for each of the cohorts analyzed. However, it should be noted that all 3 machine learning models provided accuracy of ∼85% or better and a RMSE <12. (Table 1) Figures 1 and 2 depict the typical spread and RMSE of the actual vs. predicted total composite score associated with the 3 models for aTSA (Figure 1) and rTSA (Figure 2). Discussion. The results of this study demonstrate that multiple different machine learning algorithms can be utilized to create models that predict outcomes with higher accuracy for both aTSA and rTSA, for numerous timepoints after surgery. Future research should test this model on different datasets and using different machine learning methods in order to reduce over- and under-fitting model errors. For any figures or tables, please contact the authors directly


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_1 | Pages 8 - 8
1 Feb 2021
Pour AE Patel K Anjaria M Schwarzkopf R Dorr L Lazennec J
Full Access

Introduction. Sagittal pelvic tilt (SPT) can change with spinal pathologies and fusion. Change in the SPT can result in impingement and hip instability. Our aim was to determine the magnitude of the SPT change for hip instability to test the hypothesis that the magnitude of SPT change for hip instability is less than 10° and it is not similar for different hip motions. Methods. Hip implant motions were simulated in standing, sitting, sit-to-stand, bending forward, squatting and pivoting in Matlab software. When prosthetic head and liner are parallel, femoral head dome (FHD) faces the center of the liner. FHD moves toward the edge of the liner with hip motions. The maximum distance between the FHD and the center in each motion was calculated and analyzed. To make the results more reliable and to consider the possibility of bony impingement, when the FHD approached 90% of the distance between the liner-center and liner-edge, we considered the hip “in danger for dislocation”. The implant orientations and SPT were modified by 1-degree increments and we used linear regression with receiver operating characteristic (ROC) curve and area under the curve (AUC) to determine the magnitude of SPT change that could cause instability. Results. SPT modification as low as 7° could result in dislocation during pivoting (AUC: 87.5; sensitivity: 87.9; specificity 79.8; p=0.0001). This was as low as 10° for squatting (AUC: 91.5; sensitivity: 100; specificity 75.9; p=0.0001) and as low as 13° for sit-to-stand (AUC: 94.6; sensitivity: 98; specificity 83; p=0.0001). SPT modification affects hip stability more in pivoting than sit-to-stand and squatting. Discussion. Our results show the importance of close collaboration between the hip and spine surgeons in treating patients who undergo THA and spinal fusion. The postoperative SPT modification should be considered for preoperative computer simulation for determining the implant safe zone


The Bone & Joint Journal
Vol. 101-B, Issue 8 | Pages 995 - 1001
1 Aug 2019
Nicholson JA Clement N Goudie E Robinson CM

Aims. The primary aim of this study was to establish the cost-effectiveness of the early fixation of displaced midshaft clavicle fractures. Patients and Methods. A cost analysis was conducted within a randomized controlled trial comparing conservative management (n = 92) versus early plate fixation (n = 86) of displaced midshaft clavicular fractures. The incremental cost-effectiveness ratio (ICER) was used to express the cost per quality-adjusted life-year (QALY). The Six-Dimension Short-Form Health Survey (SF-6D) score was used as the preference-based health index to calculate the cost per QALY at 12 months after the injury. Results. The mean 12-month SF-6D was 0.9522 (95% confidence interval (CI) 0.9355 to 0.9689) following conservative management and 0.9607 (95% CI 0.9447 to 0.9767) following fixation, giving an advantage for fixation of 0.0085, which was not statistically significant (p = 0.46). The mean cost per patient was £1322.69 for conservative management and £5405.32 for early fixation. This gave an ICER of £480 309.41 per QALY. For a threshold of £20 000 per QALY, the benefit of fixation would need to be present for 24 years to be cost-effective compared with conservative treatment. Linear regression analysis identified nonunion as the only factor to adversely influence the SF-6D at 12 months (p < 0.001). Conclusion. Routine plate fixation of displaced midshaft clavicular fractures is not cost-effective. Nonunion following conservative management has an increased morbidity with comparable expense to early fixation. This may suggest that a targeted approach of fixation in patients who are at higher risk of nonunion would be more cost-effective than the routine fixation of all displaced fractures. Cite this article: Bone Joint J 2019;101-B:995–1001


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_2 | Pages 36 - 36
1 Mar 2021
Langley B Whelton C Page R Chalmers O Cramp M Morrison S Dey P Board T
Full Access

Abstract. Objectives. The objective of this study was to determine the kinematic factor(s) underlying the reduction in walking velocity displayed by total hip arthroplasty (THA) patients in comparison to healthy controls during walking gait. Methods. Eleven patients with well-functioning THA (71 ± 8 years, Oxford Hip Score = 46 ± 3) and ten healthy controls (61 ± 5 years) participated within this study. Sagittal plane lower limb kinematics were captured using a 10 camera Qualisys motion capture system, sampling at 200Hz, as participants walked overground at a self-selected pace. Bivariate linear regression was used to explore the relationship between walking velocity and a number of kinematic variables in a deterministic manner. Kinematic variables significantly associated with walking velocity were compared between THA and healthy groups utilising independent samples t-tests. Results. Peak hip extension was a significant (r2 = .36; p =.004) predictor of hip range of motion. Hip range of motion significantly (r. 2. = .61 p <.001) predicted stride length. Stride length was a significant (r2 = .75; p <.001) predictor of walking velocity. Peak hip extension and range of motion, and stride length were significantly (p ≤ .033) smaller for the THA group compared to the healthy control group. Conclusions. The deterministic model developed within this study links slower walking velocities to smaller peak hip extension, via reductions in hip range of motion and stride length. Stride length, hip range of motion and peak hip extension were all significantly lower for the THA group compared to the healthy group, despite patients reporting the implants to be well-functioning. Elucidating the mechanism(s) which restrict peak hip extension within THA populations is essential for maximising functional recovery and walking velocity post-operatively. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_2 | Pages 79 - 79
1 Mar 2021
Alves J Owen M Mason D
Full Access

Abstract. Cranial cruciate ligament (CrCL) disease in dogs causes pain and osteoarthritis (OA) and surgical treatment does not prevent OA progression. Glutamate receptor (GluR) antagonists alleviate pain and degeneration in rodent models of OA, but it is unknown whether they are a suitable treatment for dogs. Understanding GluR signalling in CrCL disease may lead to novel therapeutics in both veterinary and human medicine. Objectives. To determine whether age, breed, sex, weight, and therapeutic(s) influence lameness and pre-operative radiographic OA scoring in dogs with CrCL disease and whether GluRs are expressed, in this disease. Methods. Surgical waste (CrCL and medial meniscus), clinical data, stifle radiographs, lameness scores (1–4, mild-unloading limb) were obtained with full informed consent (RCVS ethics approval, ref: 2017/14/Alves). OA scoring was performed on radiographs [VCOT, 2017, 30(6):377–384, 15–60, normal-severe OA], and α-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA)-2 and kainate (KA)-1 GluR expression compared in diseased versus control tissues by immunohistochemistry (IHC). Results. We studied 25 dogs (various breeds, 4.88±3.02 years; 44% male; 56% female; 27.13±9.12kg). At the time of surgery, 44% dogs were on meloxicam alone, 40% on other therapeutic(s) and 16% on no therapeutics. Linear regression showed that OA score (mean 21.72±3.47) did not correlate with lameness score (mean 1.98±1.08), age or weight (p values of 0.7483, 0.4597, 0.1463; R. 2. values of 0.004563, 0.02400, 0.08951, respectively). Radiographic OA scores and lameness scores did not differ between therapeutic groups (one-way ANOVA, p=0.9229 and p=0.5541, respectively). GluRs (AMPA-2/KA-1) were expressed in CrCL and medial meniscus, with increased labelling in the CrCL epiligamentous region in diseased tissues, where microanatomy was disrupted. Conclusions. In this population, OA scores do not correlate with lameness scores, age, weight, and therapeutics at the time of surgery. Variable GluR expression in diseased tissues implicates glutamate signalling in this pathology. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_1 | Pages 52 - 52
1 Feb 2021
De Grave PW Luyckx T Claeys K Gunst P
Full Access

Purpose. Various alignment philosophies for total knee arthroplasty (TKA) have been described, all striving to achieve excellent long-term implant survival and good functional outcomes. In recent years, in search of higher functionality and patient satisfaction, a shift towards more patient-specific alignment is seen. Robotics is the perfect technology to tailor alignment. The purpose of this study was to describe ‘inverse kinematic alignment’ (iKA) technique, and to compare clinical outcomes of patients that underwent robotic-assisted TKA performed by iKA versus adjusted mechanical alignment (aMA). Methods. The authors analysed the records of a consecutive series of patients that received robotic assisted TKA with iKA (n=40) and with aMA (n=40). Oxford Knee Score (OKS) and satisfaction on a visual analogue scale (VAS) were collected at a follow-up of 12 months. Clinical outcomes were assessed according to patient acceptable symptom state (PASS) thresholds, and uni- and multivariable linear regression analyses were performed to determine associations of OKS and satisfaction with 6 variables (age, sex, body mass index (BMI), preoperative hip knee ankle (HKA) angle, preoperative OKS, alignment technique). Results. The iKA and aMA techniques yielded comparable outcome scores (p=0.069), with OKS respectively 44.6±3.5 and 42.2±6.3. VAS Satisfaction was better (p=0.012) with iKA (9.2±0.8) compared to aMA (8.5±1.3). The number of patients that achieved OKS and satisfaction PASS thresholds was significantly higher (p=0.049 and p=0.003, respectively) using iKA (98% and 80%) compared to aMA (85% and 48%). Knees with preoperative varus deformity, achieved significantly (p=0.025) better OKS using iKA (45.4±2.0) compared to aMA (41.4±6.8). Multivariable analyses confirmed better OKS (β=3.1; p=0.007) and satisfaction (β=0.73; p=0.005) with iKA. Conclusions. The results of this study suggest that iKA and aMA grant comparable clinical outcomes at 12-months follow-up, though a greater proportion of knees operated by iKA achieved the PASS thresholds for OKS and satisfaction. Notably. in knees with preoperative varus deformity, iKA yielded significantly better OKS and satisfaction than aMA


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_2 | Pages 18 - 18
1 Mar 2021
Ng G Bankes M Grammatopoulos G Jeffers J Cobb J
Full Access

Abstract. OBJECTIVES. Cam femoroacetabular impingement (FAI – femoral head-neck deformity) and developmental dysplasia of the hip (DDH – insufficient acetabular coverage) constitute a large portion of adverse hip loading and early degeneration. Spinopelvic anatomy may play a role in hip stability thus we examined which anatomical relationships can best predict range of motion (ROM). METHODS. Twenty-four cadaveric hips with cam FAI or DDH (12:12) were CT imaged and measured for multiple femoral (alpha angles, head-neck offset, neck angles, version), acetabular (centre-edge angle, inclination, version), and spinopelvic features (pelvic incidence). The hips were denuded to the capsule and mounted onto a robotic tester. The robot positioned each hip in multiple flexion angles (Extension, Neutral 0°, Flexion 30°, Flexion 60°, Flexion 90°); and performed internal-external rotations to 5 Nm in each position. Independent t-tests compared the anatomical parameters and ROM between FAI and DDH (CI = 95%). Multiple linear regressions determined which anatomical parameters could predict ROM. RESULTS. The FAI group demonstrated restricted ROM in deep hip flexion, with DDH showing higher ROM in Flexion 30° (+20%, p = 0.03), 60° (+31%, p = 0.001), and 90° (+36%, p = 0.001). In Neutral 0° and Flexion 30°, femoral neck and version angles together predicted ROM (R. 2. = 60%, 58% respectively); whereas in Flexion 60°, pelvic incidence and femoral neck angle predicted ROM (R. 2. = 77%). In Flexion 90°, pelvic incidence and radial alpha angle together predicted ROM (R. 2. = 81%), where pelvic incidence alone accounted for 63% of this variance. CONCLUSIONS. Pelvic incidence is essential to predict hip ROM. Although a cam deformity or acetabular undercoverage can elevate risks of labral tears and progressive joint degeneration, they may not be primary indicators of restrictive hip impingement or dysplastic instability. Better delineating additional spinopelvic characteristics can formulate early diagnostic tools and improve opportunities for nonsurgical management. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project


The Bone & Joint Journal
Vol. 102-B, Issue 1 | Pages 26 - 32
1 Jan 2020
Parikh S Singh H Devendra A Dheenadhayalan J Sethuraman AS Sabapathy R Rajasekaran S

Aims. Open fractures of the tibia are a heterogeneous group of injuries that can present a number of challenges to the treating surgeon. Consequently, few surgeons can reliably advise patients and relatives about the expected outcomes. The aim of this study was to determine whether these outcomes are predictable by using the Ganga Hospital Score (GHS). This has been shown to be a useful method of scoring open injuries to inform wound management and decide between limb salvage and amputation. Methods. We collected data on 182 consecutive patients with a type II, IIIA, or IIIB open fracture of the tibia who presented to our hospital between July and December 2016. For the purposes of the study, the patients were jointly treated by experienced consultant orthopaedic and plastic surgeons who determined the type of treatment. Separately, the study team (SP, HS, AD, JD) independently calculated the GHS and prospectively collected data on six outcomes for each patient. These included time to bony union, number of admissions, length of hospital stay, total length of treatment, final functional score, and number of operations. Spearman’s correlation was used to compare GHS with each outcome. Forward stepwise linear regression was used to generate predictive models based on components of the GHS. Five-fold cross-validation was used to prevent models from over-fitting. Results. The mean follow-up was 11.4 months (3 to 31). The mean time to union was 9.7 months (3 to 21), the mean number of operations was 2.8 (1 to 11), the mean time in hospital was 17.7 days (5 to 84), the mean length of treatment was 92.7 days (5 to 730), the mean number of admissions was 1.7 (1 to 6), and the mean functional score (Lower Extremity Functional Score (LEFS)) was 60.13 (33 to 80). There was a significant correlation between the GHS and each of the outcome measures. A predictive model was generated from which the GHS could be used to predict the various outcome measures. Conclusion. The GHS can be used to predict the outcome of patients who present with an open fracture of the tibia. Our model generates a numerical value for each outcome measure that can be used in clinical practice to inform the treating team and to advise patients. Cite this article: Bone Joint J 2020;102-B(1):26–32


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_1 | Pages 29 - 29
1 Feb 2021
Kolessar D Harding J Rudraraju R Hayes D Graham J
Full Access

Introduction. Robotic-arm assisted knee arthroplasty (rKA) has been associated with improved clinical, radiographic, and patient-reported outcomes. There is a paucity of literature, however, addressing its cost effectiveness. In the context of an integrated health system with an insurance plan and single source comprehensive data warehouse for electronic health records and claims data, we present an evaluation of healthcare costs and utilization associated with manual knee arthroplasty (mKA) versus rKA. We also examine the influence of rKA technology on surgeons’ practice patterns. Methods. Practice patterns of KA were assessed 18 months before and after introduction of robotic technology in April 2018. For patients also insured through the system's health plan, inpatient costs (actual costs recorded by health system), 90-day postoperative costs (allowed amounts paid by insurance plan), and 90-day postoperative utilization (length of stay, home health care visits, rehabilitation visits) were compared between mKA and rKA patients, stratified by total (TKA) or unicompartmental (UKA) surgery. Linear regression modeling was used to compare outcomes between the two pairs of groups (mKA vs. rKA, for both UKA and TKA). Log-link function and gamma error distribution was used for costs. All analyses were done using SAS statistical software, with p<0.05 considered statistically significant. Results. Overall KA volume increased 21%, from 532 cases in the pre-rKA period to 644 post-rKA introduction, with UKA surgeries increasing from 38 to 97 (155%). Of these KAs, 218 patients were insured through our system's health plan (38 rUKAs, 9 mUKAs, 91 rTKAs, and 80 mTKAs), allowing precise insurance claims analysis for postoperative utilization and cost. Patients with rKA had significantly lower mean home health costs (-90% difference for UKA, −79% difference for TKA, p<0.02) and home rehab costs (-64% difference for UKA, −73% difference for TKA, p≤0.007) than mKA patients. No significant differences were observed in outpatient rehab (visits or costs), total rehab costs, or length of stay. Mean total postoperative costs were significantly lower for rUKA than mUKA (-47% difference, p=0.02) but similar for TKA (p>0.05). There were no significant differences in total inpatient costs between MAKO and non-MAKO patients. Conclusion. Robotic-arm assisted KA can allow for increased UKA volume and potential for substantial cost savings over the total episode of care by reducing postoperative utilization and costs


Rapid discharge pathways (RDP) have been implemented throughout most areas of orthopaedics. The primary goal of these pathways is to standardize the post-surgical hospital course for patients in order to decrease hospital length-of-stay (LOS). Surgical treatment of adolescent idiopathic scoliosis (AIS) remains one of the most invasive pediatric orthopaedic procedure and is routinely associated with a prolonged hospital stay. The implementation of RDPs following surgery for AIS has shown to be successful; however, all of these studies have been conducted within the United States and it has been shown previously that there exists major differences in hospital LOS and in post-operative complications between Canada and the United States. Therefore, the objective of this study was to determine if the implementation of a RDP at a single children's tertiary-referral centre in Canada could decrease hospital LOS without increasing post-operative complications. A retrospective chart review was completed for all patients who underwent posterior spinal instrumentation and fusion (PSIF) between March 1st, 2010 and February 28th, 2019, with date of implementation being March 1st, 2015. Patient pre-operative, operative, and post-operative information was collected from the charts along with the primary outcome variables: LOS, wound complication, 30-day return to the OR, 30-day emergency department admission, and 30-day hospital readmission. An interrupted time series analysis with a robust linear regression model was utilized to assess for any differences in outcomes following implementation of the RDP. Ninety days before and after the implementation of the RDP was not included in this analysis due to variances in practice that were occurring at this time. A total of 244 participants were identified, with 113 patients in the conventional pathway and 131 patients in the RDP cohort. No significant differences in pre-operative or operative characteristics existed between the groups, except for the RDP group having approximately a 50 larger pre-operative curve and the conventional pathway having on average 200mL greater intra-operative blood loss (p<0.05). Hospital LOS was found to be significantly shorter in the RDP group, with the median LOS being 5.2 [95% IQR 4.3–6.1] days in the conventional group and 3.4 [95% IQR 3.3–3.5] days in the RDP group (p<0.05). Patients in the RDP group were also found to stand 0.9 days earlier, walk 1.1 days earlier, their Foley catheter was discontinued 0.5 days earlier and their personal controlled analgesia was discontinued 12 hours sooner (p<0.05). There were no differences in post-operative complications between the two groups (p>0.05). This study demonstrates that implementing a RDP following PSIF for AIS can successfully decrease hospital LOS without increasing post-operative complications in a single payer universal healthcare system. The associated decrease in LOS could correlate with decreasing costs for both the healthcare system and for the patient's family


The Bone & Joint Journal
Vol. 101-B, Issue 7 | Pages 860 - 866
1 Jul 2019
Nicholson JA Searle HKC MacDonald D McBirnie J

Aims. The aim of this study was to investigate the influence of age on the cost-effectiveness of arthroscopic rotator cuff repair. Patients and Methods. A total of 112 patients were prospectively monitored for two years after arthroscopic rotator cuff repair using the Disabilities of the Arm, Shoulder and Hand questionnaire (DASH), the Oxford Shoulder Score (OSS), and the EuroQol five-dimension questionnaire (EQ-5D). Complications and use of healthcare resources were recorded. The incremental cost-effectiveness ratio (ICER) was used to express the cost per quality-adjusted life-year (QALY). Propensity score-matching was used to compare those aged below and above 65 years of age. Satisfaction was determined using the Net Promoter Score (NPS). Linear regression was used to identify variables that influenced the outcome at two years postoperatively. Results. A total of 92 patients (82.1%) completed the follow-up. Their mean age was 59.5 years (. sd. 9.7, 41 to 78). There were significant improvements in the mean DASH (preoperative 47.6 vs one-year 15.3; p < 0.001) and OSS scores (26.5 vs 40.5; p < 0.001). Functional improvements were maintained with no significant change between one and two years postoperatively. The mean preoperative EQ-5D was 0.54 increasing to 0.81 at one year (p < 0.001) and maintained at 0.86, two years postoperatively. There was no significant difference between those aged below or above 65 years of age with regards to postoperative shoulder function or EQ-5D gains. Smoking was the only characteristic that significantly adversely influenced the EQ-5D at two years postoperatively (p = 0.005). A total of 87 were promoters and five were passive, giving a mean NPS of 95 (87/92). The total mean cost per patient was £3646.94 and the mean EQ-5D difference at one year was 0.2691, giving a mean ICER of £13 552.36/QALY. At two years, this decreased further to £5694.78/QALY. This was comparable for those aged below or above 65 years of age (£5209.91 vs £5525.67). Smokers had an ICER that was four times more expensive. Conclusion. Arthroscopic rotator cuff repair results in excellent patient satisfaction and cost-effectiveness, regardless of age. Cite this article: Bone Joint J 2019;101-B:860–866


The Bone & Joint Journal
Vol. 101-B, Issue 2 | Pages 213 - 220
1 Feb 2019
Xu S Lim WJ Chen JY Lo NN Chia S Tay DKJ Hao Y Yeo SJ

Aims. The aim of this study was to assess the influence of obesity on the clinical outcomes and survivorship ten years postoperatively in patients who underwent a fixed-bearing unicompartmental knee arthroplasty (UKA). Patients and Methods. We prospectively followed 184 patients who underwent UKA between 2003 and 2007 for a minimum of ten years. A total of 142 patients with preoperative body mass index (BMI) of < 30 kg/m. 2. were in the control group (32 male, 110 female) and 42 patients with BMI of ≥ 30 kg/m. 2. were in the obese group (five male, 37 female). Pre- and postoperative range of movement (ROM), Knee Society Score (KSS), Oxford Knee Score (OKS), 36-Item Short-Form Health Survey (SF-36), and survivorship were analyzed. Results. Patients in the obese group underwent UKA at a significantly younger mean age (56.5 years (. sd. 6.4)) than those in the control group (62.4 years (. sd. 7.8); p < 0.001). There was no significant difference in preoperative functional scores. However, those in the obese group had a significantly lower ROM (116° (. sd. 15°) vs 123° (. sd. 17°); p = 0.003). Both groups achieved significant improvement in outcome scores regardless of BMI, ten years postoperatively. All patients achieved the minimal clinically important difference (MCID) for OKS and KSS. Both groups also had high rates of satisfaction (96.3% in the control group and 97.5% in the obese group) and the fulfilment of expectations (94.9% in the control group and 95.0% in the obese group). Multiple linear regression showed a clear association between obesity and a lower OKS two years postoperatively and Knee Society Function Score (KSFS) ten years postoperatively. After applying propensity matching, obese patients had a significantly lower KSFS, OKS, and physical component score (PCS) ten years postoperatively. Seven patients underwent revision to total knee arthroplasty (TKA), two in the control group and five in the obese group, resulting in a mean rate of survival at ten years of 98.6% and 88.1%, respectively (p = 0.012). Conclusion. Both groups had significant improvements in functional and quality-of-life scores postoperatively. However, obesity was a significant predictor of poorer improvement in clinical outcome and an increased rate of revision ten years postoperatively


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_3 | Pages 34 - 34
1 Mar 2021
MacDonald P Woodmass J McRae S Verhulst F Lapner P
Full Access

Management of the pathologic long-head biceps tendon remains controversial. Biceps tenotomy is a simple intervention but may result in visible deformity and subjective cramping. Comparatively, biceps tenodesis is technically challenging, and has increased operative times, and a more prolonged recovery. The purpose of this study was to determine the incidence of popeye deformity following biceps tenotomy versus tenodesis, identify predictors for developing a deformity, and compare subjective and objective outcomes between those that have one and those that do not. Data for this study were collected as part of a randomized clinical trial comparing tenodesis versus tenotomy in the treatment of lesions of the long head of biceps tendon. Patients 18 years of age or older with an arthroscopy confirmed biceps lesion were randomized to one of these two techniques. The primary outcome measure for this sub-study was the rate of a popeye deformity at 24-months post-operative as determined by an evaluator blinded to group allocation. Secondary outcomes were patient reported presence/absence of a popeye deformity, satisfaction with the appearance of their arm, as well as pain and cramping on a VAS. Isometric elbow flexion and supination strength were also measured. Interrater reliability (Cohen's kappa) was calculated between patient and evaluator on the presence of a deformity, and logistic regression was used to identify predictors of its occurrence. Linear regression was performed to identify if age, gender, or BMI were predictive of satisfaction in appearance if a deformity was present. Fifty-six participants were randomly assigned to each group of which 42 in the tenodesis group and 45 in the tenotomy group completed a 24-month follow-up. The incidence of popeye deformity was 9.5% (4/42) in the tenodesis group and 33% (15/45) in the tenotomy group (18 male, 1 female) with a relative risk of 3.5 (p=0.016). There was strong interrater agreement between evaluator and patient perceived deformity (kappa=0.636; p<0.001). Gender tended towards being a significant predictor of having a popeye with males having 6.6 greater odds (p=0.090). BMI also tended towards significance with lower BMI predictive of popeye deformity (OR 1.21; p=0.051). Age was not predictive (p=0.191). Mean (SD) satisfaction score regarding the appearance of their popeye deformity was 7.3 (2.6). Age was a significant predictor, with lower age associated with decreased satisfaction (F=14.951, adjusted r2=0.582, p=0.004), but there was no association with gender (p=0.083) or BMI (p=0.949). There were no differences in pain, cramping, or strength between those who had a popeye deformity and those who did not. The risk of developing a popeye deformity was 3.5 times higher after tenotomy compared to tenodesis. Male gender and lower BMI tended towards being predictive of having a deformity; however, those with a high BMI may have had popeye deformities that were not as visually apparent to an examiner as those with a lower BMI. Younger patients were significantly less satisfied with a deformity despite no difference in functional outcomes at 24 months. Thus, biceps tenodesis may be favored in younger patients with low BMI to mitigate the risk of an unsatisfactory popeye deformity


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_9 | Pages 76 - 76
1 Oct 2020
Kahlenberg CA Krell E Sculco TP Figgie MP Sculco PK
Full Access

Introduction. A large proportion of patients undergoing total knee arthroplasty (TKA) have severe osteoarthritis in both knees and may consider either simultaneous or staged bilateral TKA. The implications of staged versus simultaneously bilateral TKA for return to work are not well understood. We hypothesized that employed patients who underwent simultaneous bilateral TKA would have significantly fewer days missed from work compared to the sum of days missed from each surgery for patients who underwent staged bilateral TKA. Methods. The prospective arthroplasty registry at Hospital for Special Surgery was utilized. We identified 61 employed patients who had undergone staged bilateral TKA and 152 employed patients who had undergone simultaneous bilateral TKA and had completed the registry's return to work questionnaire. Baseline characteristics and patient reported outcome scores were evaluated. We used a linear regression model, adjusting for potential confounders including age, sex, pre-op BMI, and work type (sedentary, moderate, high activity, or strenuous), to analyze workdays lost after staged versus simultaneous bilateral TKA. Results. Staged patients missed a mean total of 67.9±46.1 days of work across both TKA surgeries, compared to 46.5±29.0 days missed in the simultaneous group (p<0.001). In multivariate mixed regression analysis, adjusted for age, sex, BMI, ASA status, and work type, the staged group missed 16.9±5.7 more days of work compared to the simultaneous group (95%CI 5.8 to 28.1, p=0.003). Compared to sedentary work type, patients with high or strenuous work activity missed 19.4±9.4 (p=0.040) more total work days. Conclusions. Employed patients undergoing simultaneous bilateral TKA missed 17 fewer days of work over the course of their surgical treatment and rehabilitation compared to those undergoing staged bilateral TKA. This information may be useful to surgeons counseling patients with bilateral knee osteoarthritis about staged versus simultaneous bilateral surgery


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_11 | Pages 105 - 105
1 Dec 2020
Marchiori G Berni M Veronesi F Cassiolas G Muttini A Barboni B Martini L Fini M Lopomo NF Marcacci M Kon E
Full Access

No therapeutic strategy, administered in the early stage of osteoarthritis (OA), is fully able to block the degenerative and inflammatory progress of the pathology, whose only solution remains surgery. Aiming to identify minimally invasive therapies able to act on both degenerative and inflammatory processes, infiltrative treatments based on mesenchymal stem cells represent a promising solution due to their proliferative, immunomodulatory, anti-inflammatory, and paracrine ability. Accordingly, the aim of the present study was to investigate the performance of different cell therapies (stem cells from adipose tissue, ADSCs, stromal vascular fraction, SVF, and culture expanded, AECs vs negative control NaCl) in the treatment of OA. An in vivo model of early OA was developed in sheep knee (research protocol N.62/2018-PR date 29/01/2018 approved by the local Ethical Committee). Three and six months after the treatments injections, gross evaluation of articular surfaces (damage score, DS), histological (cartilage thickness, Th; fibrillation index, FI; collagen II content, C2) and mechanical assessment (elastic modulus, E; stress-relaxation time, τ) of cartilage were carried out. Due to the importance of the relationship between structure/composition (histology) and function (mechanics), this study investigated which of the revealed parameters were involved in such relation and how they were influenced by the level of degeneration and by the specific cell treatment, thus to better understand cell-tissue interaction. A statistically significant multi-variable linear regression model was found between τ and Th, FI, C2 (R2 0.7, p-value 8.39E-5). The relation was particularly strong between τ and C2 (p-value 7E-4), with a positive coefficient of 0.92. This is in agreement with literature, where a higher cartilage viscosity was related to a major content of collagen. By dividing the samples in two groups depending on cartilage damage, the more degenerated group (DS > 5) showed statistically significant lower C2 (p-value 0.0124) and τ (p-value 0.05), confirming that collagen content and viscosity decrease with OA grade increasing. Averaging the entire group of samples, the OA degeneration progressed between 3 and 6 months after, and despite, the treatment. But focusing on specific treatments, SVF and AECs differed from the general trend, inducing a higher amount of collagen at 6 months respect to 3 months. Moreover, articular cartilage treated by AECs and, overall, SVF showed a higher content of collagen and a major viscosity respect to the other treatments. We conclude that an injection of mesenchymal stem cells from stromal vascular fraction in early OA articulations could hinder the degenerative process, preserving or even restoring collagen content and viscosity of the articular cartilage


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_9 | Pages 35 - 35
1 Oct 2020
Mahoney OM
Full Access

Introduction. The role of the (PCL) in modulating knee kinematics has been well documented. We asked whether function of the (PCL) would be better preserved by incorporating a three-dimensional model for planning and placement. Methods. We evaluated patients (n=59) enrolled into a, prospective, study of conventional instrumentation (25) vs. 3D modeling (34) for (CR) TKA from July 2016 to Feb 2018. Follow-up included clinical exams, PROMs, and serial radiographs up to 24 months after surgery. We measured kinematic patterns radiographically at two years postoperatively. Variables were compared using simple linear regression, one-way ANOVA, and Fisher's exact test. We hypothesized that: 1. well-preserved PCL would demonstrate a more normal kinematic pattern of increasing rollback with increasing knee flexion without paradoxical movement, and 2. this pattern would be associated with improved intra- and post-operative motion and function. Results. The 3D group exhibited a monotonic pattern of increasing rollback in more than twice the proportion of patients as the conventional group (18/34 (53%) vs. 6/25(24%), p=0.034). Two yrs post-operatively, the maximum active flexion was 5 deg greater on average for the 3D group (mean(SD) 111.8(6.6) vs. 106.8 (8.8), p=0.015), and we saw positive linear correlation of femoral rollback with maximum active (r=.39, p=0.002) and passive (r=.45, p<0.001) flexion. Increased rollback was correlated with better Knee Society symptom scores during the early post-operative period (r=.37, p=0.003 and r=.39, p=0.002, respectively). Discussion. This study demonstrates the value of 3D reconstructions to improve kinematics in TKA. In fact, PCL retaining TKA has been consistently linked to paradoxical rollback, predisposing the extensor mechanism to increased stress and reduced femoral clearance, limiting flexion. Paradoxical movement was more prevalent in conventionally instrumented knees. There were notable differences in PROMS even at six weeks post TKR. More normal kinematics were associated with increased motion and improved patient reported outcomes. For any figures or tables, please contact the authors directly


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_IV | Pages 556 - 556
1 Nov 2011
Miniaci A Fening SD
Full Access

Purpose: Osteochondral allograft transplantation for the treatment of osseous defects to the humeral head has recently grown in popularity. Because only a portion of the articulating surface of the humeral head is replaced, conformity of the allograft to the native surface is imperative to restore the natural geometry of the joint. To achieve proper conformity, it is essential that the curvature of the humeral head of the allograft tissue match that of the native tissue. Curvature determination is also important for shoulder replacement procedures. Curvature of the humeral head is difficult to directly measure in allograft specimens. As a result, predictive measurements, such as the maximum length of the humerus are used to predict this curvature. The purpose of this study was to investigate the value of various anthropometric measurements for predicting humeral head curvature. We hypothesized that the maximum length of the humerus would be the most predictive of humeral curvature. Method: 60 (28 female, 32 male) cadaveric humeri were obtained from the Hamann-Todd Human Osteological Collection. Specimens ranged from 20 to 35 years of age at the time of death (27.9 ± 4.5, mean ± SD). Specimens from this collection include height and weight as collected at the time of death. All specimens were scanned with a 3-dimensional laser scanner (NextEngine, Santa Monica, California, USA). This scanner has been shown to be accurate to within 0.005 inches. Linear measurements (maximum humeral length, epicondylar breadth) were made according to the recording standards for skeletal remains. Both measurements were made by choosing points on the 3-dimensional scan, rather than the traditional osteometric board. Humeral head curvature was determined by a custom computational code to fit a sphere to the articulating surface of the humerus. Data analysis was performed in Minitab (version 13, State College, PA, USA). A linear regression was performed for each predictive measurement. A stepwise linear regression with forward and backward substitution was performed for the most predictive variables from the initial linear regression. Results: The most predictive factors (R^2 > 0.5) were epicondylar breadth, height, maximum humeral length, and gender. Based on the linear regression coefficients, these four factors (all normalized) were included in a forward and backward stepwise regression (alpha to enter and remove = 0.15). The resulting equation (shown below) had an R^2 values of 0.807. Humeral Diameter = 0.894 + 0.048*(epicondylar breadth) + 0.043*height – 0.020*gender. Conclusion: Of the predicted measurements evaluated, patient height, epicondylar breadth, and gender were most correlated with humeral head curvature. Including these three factors in a linear regression model increased the R2 value to 0.807. If only a single measurement can be used to size the humeral curvature, patient height will give approximately the same accuracy as epicondylar breadth, and can more easily be obtained


The Bone & Joint Journal
Vol. 100-B, Issue 4 | Pages 480 - 484
1 Apr 2018
Kadum B Inngul C Ihrman R Sjödén GO Sayed-Noor AS

Aims. The aims of this study were to investigate any possible relationship between a preoperative sensitivity to pain and the degree of pain at rest and on exertion with postoperative function in patients who underwent stemless total shoulder arthroplasty (TSA). Patients and Methods. In this prospective study, we included 63 patients who underwent stemless TSA and were available for evaluation one year postoperatively. There were 31 women and 32 men; their mean age was 71 years (53 to 89). The pain threshold, which was measured using a Pain Matcher (PM) unit, the degree of pain (visual analogue scale at rest and on exertion, and function using the short version of the Disabilities of the Arm, Shoulder and Hand questionnaire (QuickDASH), were recorded preoperatively, as well as three and 12 months postoperatively. Results. We found an inverse relationship between both the preoperative PM threshold and pain (VAS) at rest and the 12-month postoperative QuickDASH score (Pearson correlation coefficient (r) ≥ 0.4, p < 0.05). A linear regression analysis showed that the preoperative PM threshold on the affected side and preoperative pain (VAS) at rest were the only factors associated with the QuickDASH score at 12 months. Conclusion. These findings indicate the importance of central sensitization in the restoration of function after TSA. Further studies are required to investigate whether extra analgesia and rehabilitation could influence the outcome in at risk patients. Cite this article: Bone Joint J 2018;100-B:480–4


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_3 | Pages 47 - 47
1 Apr 2018
Wylde V Trela-Larsen L Whitehouse M Blom A
Full Access

Background. Total knee replacement (TKR) is an effective operation for many patients, however approximately 20% of patients experience chronic pain and functional limitations in the months and years following their TKR. If modifiable pre-operative risk factors could be identified, this would allow patients to be targeted with individualised care to optimise these factors prior to surgery and potentially improve outcomes. Psychosocial factors have also been found to be important in predicting outcomes in the first 12 months after TKR, however their impact on long-term outcomes is unknown. This study aimed to identify pre-operative psychosocial predictors of patient-reported and clinician-assessed outcomes at one year and five years after primary TKR. Patients and methods. 266 patients listed for a Triathlon TKR because of osteoarthritis were recruited from pre-operative assessment clinics at one orthopaedic centre. Knee pain and function were assessed pre-operatively and at one and five years post-operative using the WOMAC Pain score, WOMAC Function score and American Knee Society Score (AKSS) Knee score. Pre-operative depression, anxiety, catastrophizing, pain self-efficacy and social support were assessed using patient-reported outcome measures. Statistical analyses were conducted using multiple linear regression and mixed effect linear regression, and adjusted for confounding variables. Results. Higher anxiety was a predictor of worse self-reported pain at one year post-operative. Higher anxiety and catastrophizing were predictive of worse self-reported function at one year post-operative. No psychosocial factors were associated with any outcome measures at five years post-operative. Analysis of change over time found that patients with higher pain self-efficacy had lower pre-operative pain and experienced less improvement in pain up to one year. Higher pain self-efficacy was associated with less improvement in the AKSS up to one year post-operative but more improvement between one and five years post-operative. Conclusion. This study found that pre-operative anxiety and catastrophizing influence outcomes at one year after TKR, highlighting that some patients may benefit from targeted psychological interventions to reduce these risk factors and improve outcomes. However, none of the psychosocial variables assessed were predictors of outcomes at five years post-operative, suggesting that the negative effects of anxiety and catastrophizing on outcome do not persist in the longer term


The Bone & Joint Journal
Vol. 99-B, Issue 9 | Pages 1147 - 1152
1 Sep 2017
Lainiala O Reito A Jämsä P Eskelinen A

Aims. To determine whether there is any association between glomerular filtration rate (GFR) and blood cobalt (Co) and chromium (Cr) levels in patients with metal-on-metal (MoM) hip arthroplasty. Patients and Methods. We identified 179 patients with a unilateral 36 mm diameter head as part of a stemmed Summit-Pinnacle MoM hip arthroplasty. GFR was calculated using the Modification of Diet in Renal Disease formula. Results. Normal renal function (GFR ≥ 90 ml/min/1.73 m. 2. ) was seen in 74 patients. Mild renal insufficiency (GFR 60 to 89 ml/min/1.73 m. 2. ) was seen in 90 patients and moderate renal insufficiency (GFR 30 to 59 ml/min/1.73 m. 2. ) in 15. There was no statistical difference in Co and Cr levels between patients with normal renal function and those with mild or moderate renal insufficiency. No correlation was seen between creatinine and blood metal ion levels or between GFR and blood metal ion levels. Linear regression analysis did not show any association between Co and Cr levels and GFR. Conclusion. We did not find any association between GFR and blood metal ion levels. Consequently, the accumulation of Co and Cr in blood due to renal insufficiency does not seem to be a major risk in patients with mild or moderate renal insufficiency. Cite this article Bone Joint J 2017;99-B:1147–52


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_4 | Pages 59 - 59
1 Apr 2018
Kastoft R Penny J Bencke J Speedtsberg M Barfod K
Full Access

Achilles tendon (AT) rupture may lead to complaints of heel pain. In forefoot ulcer patients AT lengthening is used to transfer pressure from forefoot to the heel. The primary aim was to investigate if AT was longer or associated with changes in pedobaric measurements, in particular heel pressure, on the injured leg 4–5 years after the injury. Methods. We invited all participants from an RCT (n=56) of conservatively treated AT Rupture (ATR) with or without early weight-bearing (early-WB, non-WB). 37 patients participated, 19 from early-WB (1 re-rupture (RR)), and 18 from non-WB (2 RR). Time from injury to follow up was 4,5 years (4,1 to 5,1). AT length was measured using ultrasound with a validated protocol. Foot pressure mapping (FPM) was measured barefoot, using an EMED platform (novel, Germany), with 5 trials for each foot. Statistics. T-test for limb to limb comparisons and linear regression for correlations was applied. Results. We found no differences in any of the variables between the early-WB and non-WB groups. Compared to the uninjured limb, the Achilles tendon was an average of 1.8 (1.2–2.3) cm longer on the injured limb (p<0.001). When comparing the ratio of the medial (1–2 ray) to lateral (3–5 ray) forefoot mean peak pressure, we found no difference between the injured and healthy limb (p=0.26). Mean heel peak pressure was not different from the injured to the healthy leg (difference was 3,9 (−1,7 – 9,45) p=0,17). Heel lift-off was delayed in the injured limb by 2% (0.4%–4.4%) of the total roll over process (ROP) (p= 0.02). Achilles tendon length could not be linked to either heels lift-off or mean peak pressure of the heel using linear regression (p 0.27 to 0.78). Conclusion. Conservatively treated Achilles tendon ruptures were approximately 1.8 cm longer. A subtle change in the time of heel rise could be detected on the injured limb, but contrary to our expectations AT length did not correlate to time of heel lift or mean heel peak pressure. This is in contrast to the common practice in diabetics, where the Achilles tendon is elongated to relieve pressure from the forefoot – a mechanism we cannot observe from elongation of the tendon after acute rupture, treated conservatively - though this study is underpowered


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_11 | Pages 102 - 102
1 Dec 2020
Chen J Ahmed A Ackermann P
Full Access

Growth factors are reported to play an important role in healing after acute Achilles tendon rupture (ATR). However, the association between growth factors and patient outcome has not been investigated previously. The aim of this retrospective study is to identify growth factors and related proteins which can be used as predictors of healing after ATR, ethical approval was obtained from the Regional Ethical Review Committees in Sweden and followed the guidelines of the Declaration of Helsinki. The study included 28 surgically treated patients (mean age 39.11 ± 8.38 yrs) with acute ATR. Healing was assessed by microdialysate two weeks after the surgery and performed on both injured and contralateral un-injured leg. The microdialysates were analyzed by proteomics based on mass spectrometry (MS) to detect growth factor expressions in ATR patients. One year after the surgery, healing outcomes were evaluated by patient-reported Achilles tendon Total Rupture Score (ATRS), Foot and Ankle Outcome Score (FAOS), and functional outcomes by heel-rise test. A total of 1549 proteins were detected in the microdialysates of which 20 growth factor/ related proteins were identified. 7 of these were significantly up-regulated (IGFBP2, Fold change (FC) = 4.07, P = 0.0036; IGFBP4, FC = 3.06, P = 0.009; CTGF, FC = 15.83, P = 0.003; HDGF, FC = 4.58, P = 0.003; GRB2, FC = 14.8, P = 0.0004; LTBP1, FC = 12.08, P = 0.0008; TGFBI, FC = 5.54, P = 0.001) and 1 down-regulated (IGFBP6) in the injured compared to the contralateral healthy side. Linear regression analysis revealed that TGFB1 was positively associated with improved ATRS (r = 0.585, P = 0.04) as well to ATRS subscales: less limitation in running (r = 0.72, P = 0.004), less jumping limitation (r = 0.764, P = 0.001) and less limitation caused by decreased tendon strength (r = 0.665, P = 0.012). Interestingly, all 7 up-regulated proteins were positively associated with less jumping limitations (IGFBP2, r = 0.667, P = 0.015; IGFBP4, r = 0.675, P = 0.013; CTGF, r = 0.668, P = 0.015; HDGF, r = 0.672, P = 0.014; GRB2, r = 0.665, P = 0.016; LTBP1, r = 0.663, P = 0,016). No associations were observed among any of the growth factor and FAOS or patient's functional outcomes. We conclude that growth factors and related proteins play a crucial role in ATR healing. More specifically, TGFB1 may be used as prognostic biomarker of the patient-reported outcome 1-year post-surgery. These results may be used to develop more specific treatments to improve ATR healing


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_8 | Pages 111 - 111
1 May 2016
Knowlton C Bhutani P Wimmer M
Full Access

Introduction. Wear of the ultra-high molecular weight polyethylene (UHWMPE) component and the subsequent aseptic loosening remains a primary reason for late revision of total knee replacements (TKRs).[1] While improved measurement techniques have provided more quantitative information on the wear of surgically retrieved inserts, it is not well understood how observed damage patterns translate to volume loss of polyethylene in vivo. The overall purpose of this study is to investigate the relationship of damage patterns and volume loss at the articular surface of total knee replacements. We hypothesize that damage patterns are reliable predictors of volume loss. Methods. Two different investigators independently analyzed damage patterns and volume loss on 43 revision- and 21 postmortem-retrieved MG II (Zimmer Inc.) tibial UHMWPE components. Areas of damage patterns on the articular surfaces were outlined with a video microscope (SmartScope, OGP) and were separated into four spatially exclusive categories (Fig. 1): delamination, pitting, striations and polishing. Articular surfaces were digitized with a low-incidence laser coordinate measuring machine (SmartScope, OGP). Autonomous reconstruction, a previously described and validated method,[2] calculated volume loss on the medial and lateral sides of each component. To investigate the predictability of volume loss using observed patterns, stepwise linear regression models were rendered in PASW Statistics 18 (SPSS Inc). Results. Components with total volume loss higher than 300 mm3 exhibited the jagged and flaky surface topography characteristic of severe delamination. Excluding delaminated components, the population's total wear rate (±95% CI) was 12.9 ± 5.97 mm3/year (Pearson's r = 0.527, p < 0.001), which accounted for volume loss due to creep (Figure 2). The wear rates on the medial side (6.56 ± 3.91 mm3/year, Pearson's r = 0.434, p = 0.002) and on the lateral side (6.32 ± 3.44 mm3/year, Pearson'sr = 0.467, p < 0.001) were not significantly different (p = 0.926). Linear regression models that included delaminated components revealed that delaminated and striated areas were significant predictors of volume (Figure 3 - Table 1). Pitted area was also a significant factor on the total part, but fell out of the medial and lateral models. When delaminated components were excluded, volume loss was similarly explained by striated and pitted areas on the medial side and total part. However, the adjusted R2 of these models was low − 0.177 and 0.166, respectively. Discussion. We found that damage patterns were not reliable surrogates for material volume loss. Other than delamination, area of striated patterns best predicted volume loss. However, the large reduction in adjusted R2 of the linear regression model indicates that delaminated areas were essential to explaining variations in the volume loss. While other groups have reported striations on retrievals [3], this damage pattern remains widely unrecognized in retrieval and knee simulator studies, with the mechanism poorly understood. To view tables/figures, please contact authors directly


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_11 | Pages 44 - 44
1 Dec 2020
Torgutalp ŞŞ Korkusuz F
Full Access

Background. Although there are predictive equations that estimate the total fat mass obtained from multiple-site ultrasound (US) measurements, the predictive equation of total fat mass has not been investigated solely from abdominal subcutaneous fat thickness. Therefore, the aims of this study were; (1) to develop regression-based prediction equations based on abdominal subcutaneous fat thickness for predicting fat mass in young- and middle-aged adults, and (2) to investigate the validity of these equations to be developed. Methods. The study was approved by the Local Research Ethics Committee (Decision number: GO 19/788). Twenty-seven males (30.3 ± 8.7 years) and eighteen females (32.4 ± 9.5 years) were randomly divided into two groups as the model prediction group (19 males and 12 females) and the validation group (8 males and 6 females). Total body fat mass was determined by dual-energy X-ray absorptiometry (DXA). Abdominal subcutaneous fat thickness was measured by US. The predictive equations for total fat mass from US were determined as fat thickness (in mm) × standing height (in m). Statistical analyses were performed using R version 4.0.0. The association between the total fat mass and the abdominal subcutaneous fat thickness was interpreted using the Pearson test. The linear regression analysis was used to predict equations for total body fat mass from the abdominal subcutaneous fat thickness acquired by US. Then these predictive equations were applied to the validation group. The paired t-test was used to examine the difference between the measured and the predicted fat masses, and Lin's concordance correlation coefficient (CCC) was used as a further measure of agreement. Results. There was a significant positive moderate correlation between the total fat mass and the abdominal subcutaneous fat thickness × height in the model prediction group of males (r = 0.588, p = 0.008), whereas significant positive very strong correlation was observed in the model prediction group of females (r = 0.896, p < 0.001). Predictive equations for DXA-measured total body fat mass from abdominal subcutaneous fat thickness using US were as follows: for males “Fat mass-DXA = 0.276 × (Fat thickness-US × Height) + 17.221” (R. 2. = 0.35, SEE = 3.6, p = 0.008); for females “Fat mass-DXA = 0.694 x (Fat thickness-US × Height) + 7.085” (R. 2. = 0.80, SEE = 2.8, p < 0.001). When fat mass prediction equations were applied to the validation groups, measured- and estimated-total fat masses in males and females were found similar (p = 0.9, p = 0.5, respectively). A good level of agreement between measurements in males and females was attained (CCC = 0.84, CCC = 0.76, respectively). Conclusion. We developed and validated prediction equations that are convenient for determining total fat masses in young- and middle-aged adults using abdominal subcutaneous fat thickness obtained from the US. The abdominal subcutaneous fat thickness obtained from a single region by US might provide a noninvasive quick and easy evaluation not only in clinical settings but also on the field


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_11 | Pages 9 - 9
1 Dec 2020
Meermans G Kats J Doorn JV Innman M Grammatopoulos G
Full Access

Introduction. In total hip arthroplasty, a high radiographic inclination angle (RI) of the acetabular component has been linked to short- and long-term complications. There are several factors that lead to RI outliers including cup version, pelvic orientation and angle of the cup introducer relative to the floor. The primary aim of this study was to analyse what increases the risk of having a cup with an RI outside the target zone when controlling cup orientation with a digital inclinometer. Methods. In this prospective study, we included 200 consecutive patients undergoing uncemented primary THA in the lateral decubitus position using a posterior approach. Preoperatively, the surgeon determined the target intraoperative inclination (IOI. target. ). The intra-operative inclination of the cup (IOI. cup. ) was measured with the aid of a digital inclinometer after seating of the acetabular component. Anteroposterior pelvic radiographs were made to measure the RI of the acetabular component. The target zones were defined as 30°-45° and 35°-45° of RI. The operative inclination relative to the sagittal plane of the pelvis (OI. math. ) was calculated based on the radiographic inclination and anteversion angle. The difference between two outcome measures was expressed as Δ. Results. The mean RI was 37.9° SD 4.7, there were 12 cases with RI outside the 30°– 45° zone (6%) and 53 outliers (26.5%) with RI outside the 35°-45° zone. The mean absolute ΔIOI. cup. -IOI. target. was 1.2° SD 1.0. The absolute ΔIOI. cup. -IOI. target. was less than 1° in 108 patients (54%), less than 2° in 160 patients (80%), less than 3° in 186 patients (93%), and in 14 patients (7%) the difference was 3°-5°. The mean pelvic motion (ΔOI. math. -IOI. cup. ) was 8.8° SD 3.9 (95% CI 8.2° to 9.3°). The absolute deviation from the mean ΔOI. math. -IOI. cup. , which corresponds with the amount of pelvic motion, was significantly higher in RI outliers compared with non-outliers for both the 30°-45° and 35°-45° inclination zone (7.4° SD 3.3 vs 2.8° SD 2.1 and 4.7° SD 2.8 vs 2.5° SD 2.0 respectively) (p<0.0001). A linear regression analysis demonstrated a strong correlation between ΔOI. math. -IOI. cup. and the RI of the cup (r. 2. =0.70; P<0.0001). A multiple regression was run to predict ΔOI. math. -IOI. cup. from gender, BMI, side and hip circumference. These variables statistically significantly predicted ΔOI. math. -OIa. cup. , F(4, 195) = 19,435, p<0.0001, R2 = 0.285, but only side (p=0.04) and hip circumference (p<0.0001) added statistically significantly to the prediction. Discussion and Conclusion. When using a digital inclinometer 94% of cups had a RI within a 30°-45° zone and 73.5% of cups within a 35°-45° zone using a predefined IOI. target. based on the patient's hip circumference. The difference between the IOI. target. and the IOI. cup. of the acetabular component was less than 3° in 93% and less than 5° in all patients signifying that the surgeons were able to implant the cup close to their chosen intra-operative orientation. Deviation from the mean ΔOI. math. -IOI. cup. was significantly bigger in the RI outliers indicating that RI outliers were caused by more or less than deviation of the sagittal plane of the pelvis at time of cup impaction


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_7 | Pages 60 - 60
1 Jul 2020
Symes M Gagne O Penner M Veljkovic A Younger ASE Wing K
Full Access

Numerous studies have demonstrated that concomitant lower back pain (LBP) results in worse functional outcomes in patients undergoing surgical treatment for the management of end stage hip and knee arthritis. However, no equivalent studies have analysed the impact of back pain on the outcomes of patients with end stage ankle arthritis. Furthermore, given that two widely accepted surgical options exist in the treatment of ankle arthritis, namely total ankle arthroplasty (TAA) and ankle arthrodesis (AA), it is possible that one surgical technique may be superior in patients with LBP. The aim of this study was to determine the incidence of LBP in people with ankle arthritis, analyse its effect on functional outcomes, and explore whether there was a treatment advantage from either TAA or AA. Prospectively collected data from the Canadian Orthopaedic Foot and Ankle Society (COFAS) database of ankle arthritis was analysed in this study. All patients with ankle arthritis who underwent surgery performed by three fellowship-trained foot and ankle surgeons at a single institution between January 2003 and July 2012 were studied. Patient demographics were collected pre-operatively, including the absence or presence of back pain, and post-operative follow up was performed at 2 and 5 years, evaluating patient-reported functional outcome measures including the Ankle Arthritis Score (AAS) and the 36-item short form survey (SF-36). Using a linear regression model, a multivariate analysis was performed to examine the relationship between back pain, TAAs and AAs. In total, 451 patients were studied. 164 patients (36.4%) presented with concomitant LBP. At presentation, the LBP group had worse AAS scores (54.8 vs 57.8 p. At 2 years postoperatively, the AAS score was the same in both groups (28.9 vs 26.8 p = 0.3), but patients with LBP had worse SF-36 PCS (42.1 vs 36.6 p 0.05) in any of the functional outcome scores at 2 or 5 years post-operatively. The results of this study suggest there is no advantage of TAA over AA in the treatment of ankle arthritis in patients with concomitant lower back pain. Although pre-operative back pain resulted in worse SF-36 outcomes at 2 and 5 years post- operatively, this was not the case for AAS scores