Aims. The aim of this study was to develop and evaluate machine-learning-based computerized adaptive tests (CATs) for the Oxford Hip Score (OHS), Oxford Knee Score (OKS), Oxford Shoulder Score (OSS), and the Oxford Elbow Score (OES) and its subscales. Methods. We developed CAT algorithms for the OHS, OKS, OSS, overall OES, and each of the OES subscales, using responses to the full-length questionnaires and a machine-learning technique called regression tree learning. The algorithms were evaluated through a series of simulation studies, in which they aimed to predict respondents’ full-length questionnaire scores from only a selection of their item responses. In each case, the total number of items used by the CAT algorithm was recorded and CAT scores were compared to full-length questionnaire scores by mean, SD, score distribution plots, Pearson’s correlation coefficient, intraclass correlation (ICC), and the Bland-Altman method. Differences between CAT scores and full-length questionnaire scores were contextualized through comparison to the instruments’ minimal clinically important difference (MCID). Results. The CAT algorithms accurately estimated 12-item questionnaire scores from between four and nine items. Scores followed a very similar distribution between CAT and full-length assessments, with the mean score difference ranging from 0.03 to 0.26 out of 48 points. Pearson’s correlation coefficient and ICC were 0.98 for each 12-item scale and 0.95 or higher for the OES subscales. In over 95% of cases, a patient’s CAT score was within five points of the full-length questionnaire score for each 12-item questionnaire. Conclusion. Oxford Hip Score, Oxford Knee Score, Oxford Shoulder Score, and Oxford Elbow Score (including separate subscale scores) CATs all markedly reduce the burden of items to be completed without sacrificing score accuracy. Cite this article: Bone Jt Open 2022;3(10):786–794

This study aimed to examine the effect of high tibial osteotomy (HTO) on the ankle and subtalar joints via analysis of static radiographic alignment. We hypothesised that surgical alteration of the alignment of the proximal tibia would result in compensatory distal changes. 35 patients recruited as part of the wider Biomechanics and Bioengineering Centre Versus Arthritis HTO study between 2011 and 2018 had pre- and postoperative full-length weightbearing radiographs taken of their lower limbs. In addition to standard alignment measures of the limb and knee (mechanical tibiofemoral angle, Mikulicz point, medial proximal tibial angle), additional measures were taken of the ankle/subtalar joints (lateral distal tibial angle, ground-talus angle, joint line convergence angle of the ankle) as well as a novel measure of stance width. Results were compared using a paired T-test and Pearson's correlation coefficient. Following HTO, there was a significant (5.4°) change in subtalar alignment. Ground-talus angle appeared related both to the level of malalignment preoperatively and the magnitude of the alignment change caused by the HTO surgery; suggesting subtalar positioning as a key adaptive mechanism. In addition to compensatory changes within the subtalar joints, the patients on average had a 31% wider stance following HTO. These two mechanisms do not appear to be correlated but the morphology of the tibial plafond may influence which compensatory mechanisms are employed by different subgroups of HTO patients. These findings are of vital importance in clinical practice both to anticipate potential changes to the ankle and subtalar joints following HTO but it could also open up wider indications for HTO in the treatment of ankle malalignment and osteoarthritis

Accurate measurement of pelvic tilt (PT) is critical in diagnosing hip and spine pathologies. Yet a sagittal pelvic radiograph with good quality is not always available. Studies explored the correlation between PT and sacro-femoral-pubic (SFP) angle from anteroposterior (AP) radiographs yet demonstrated conflicting conclusions about its feasibilities. This study aims to perform a cohort-controlled meta-analysis to examine the correlation between the SFP angle and PT and proposes an application range of the method. This study searched PubMed, Embase, Cochrane, and Web of Science databases for studies that evaluated the correlation between SFP angle and PT. The Pearson's correlation coefficient r from studies were tabulated and compared. Pooled r for overall and gender/age (teenage or adult) controlled subgroup were reported using Fisher's Z transformation. Heterogeneity and publication bias were evaluated using Egger's regression test for the funnel plot asymmetry. Eleven studies were recruited, with nine reported r (totalling 1,247 patients). The overall pooled r was 0.61 with high inter-study heterogeneity (I2 = 75.95%). Subgroup analysis showed that the adult group had a higher r than the teenage group (0.70 versus 0.56, p < 0.001). Although statistically insignificant (p = 0.062), the female group showed a higher r than the male group (0.72 versus 0.65). The SFP method must be used with caution and should not be used in the male teenage group. The current studies did not demonstrate that the SFP method was superior to other AP landmarks correlating to PT. Identical heterogeneity was observed among studies, indicating that more ethnicity-segregated and gender-specific subgroup studies might be necessary. More data input analysing the errors will be useful

Aim. The analysis of synovial fluid has proved to be of crucial importance in the diagnostic process of prosthetic joint infections (PJI), suggesting the presence of an infection before the microbiological culture results. In this context, several studies illustrated the efficacy of synovial calprotectin in supporting the diagnosis of PJI [1, 2]. However, several testing methods have been explored to detect synovial calprotectin levels, emphasizing the need to use a standardized, rapid and rapid test. In this study, synovial calprotectin was analyzed by means of a commercial stool test [3] to explore whether the detected levels might predict PJIs and, therefore, being a promising tool for the fast and reliable diagnosis of this complication. Method. The synovial fluid of 55 patients underwent to revision of the prosthetic implant were analyzed. The measurement of calprotectin was carried out by of commercial stool test, following the protocol for liquid samples. Calprotectin levels were then compared to other synovial biomarkers of PJI such as leucocyte esterase and count and percentage of polymorphonuclear cells. Data analysis were performed using R software v4.1.1 (R Core Team) and package “pROC” [4]. Receiver operator characteristics curves were designed using culture test as gold standard to evaluate the area under curve (AUC) of each method (with DeLong method for confidence-interval calculation). Thresholds were calculated to maximize Youden's index; sensitivity and specificity were reported. One-to-one Pearson's correlations coefficient were calculated for each pair of methods. P value <0.05 were considered statistically significant. Results. Of the 55 synovial fluids analyzed, 13 patients were diagnosed with PJI and 42 with an aseptic failure of the implant. The specificity, sensitivity, and AUC of calprotectin resulted 0.90, 0.85, and 0.86 (95%CI: 0.72–0.99), respectively with a set threshold of 226.5 µg/g. The values of calprotectin had a moderate and statistically relevant correlation with the synovial leucocyte counts (r. s. = 0.54, p = 0.0003) and the percentage of polymorphonuclear cells (r. s. = 0.68, p = 0.0000). Conclusions. From this analysis, it can be concluded that synovial calprotectin is a valuable biomarker that correlates with other established indicator of local infection, delivering a rapid and reliable results and supporting the diagnostic process of PJI

The Banff Patellofemoral Instability Instrument 2.0 (BPII 2.0) is a patient-reported disease-specific quality of life (QOL) outcome measure used to assess patients with recurrent lateral patellofemoral instability (LPI) both pre- and post-operatively. The purpose of this study was to compare the BPII 2.0 to four other relevant patient reported outcome measures (PROMs): the Tampa Scale-11 for kinesiophobia (TSK-11), the pain catastrophizing scale (PCS), a general QOL (EQ-5D-5L), and a return to sport index (ACL-RSI). This concurrent validation sought to compare and correlate the BPII 2.0 with these other measures of physical, psychological, and emotional health. The psychological and emotional status of patients can impact recovery and rehabilitation, and therefore a disease-specific PROM may be unable to consistently identify patients who would benefit from interventions encompassing a holistic and person-focused approach in addition to disease-specific treatment. One hundred and ten patients with recurrent lateral patellofemoral instability (LPI) were assessed at a tertiary orthopaedic practice between January and October 2021. Patients were consented into the study and asked to complete five questionnaires: the BPII 2.0, TSK-11, PCS, EQ-5D-5L, and the ACL-RSI at their initial orthopaedic consultation. Descriptive demographic statistics were collected for all patients. A Pearson's r correlation coefficient was employed to examine the relationships between the five PROMs. These analyses were computed using SPSS 28.0 © (IBM Corporation, 2021). One hundred and ten patients with a mean age of 25.7 (SD = 9.8) completed the five PROMs. There were 29 males (26.3%) and 81 females (73.6%) involving 50% symptomatic left knees and 50% symptomatic right knees. The mean age of the first dislocation was 15.4 years (SD = 7.3; 1-6) and the mean BMI was 26.5 (SD = 7.3; range = 12.5-52.6) The results of the Pearson's r correlation coefficient demonstrated that the BPII 2.0 was statistically significantly related to all of the assessed PROM's (p. There was significant correlation evident between the BPII 2.0 and the four other PROMs assessed in this study. The BPII 2.0 does not explicitly measure kinesiophobia or pain catastrophizing, however, the significant statistical relationship of the TSK-11 and PCS to the BPII 2.0 suggests that this information is being captured and reflected. The preliminary results of this concurrent validation suggest that the pre-operative data may offer predictive validity. Future research will explore the ability of the BPII 2.0 to predict patient quality of life following surgery

A hip fracture represents the extreme end of osteoporosis, placing a significant burden on secondary care, society, and the individual patient. The National Hip Fracture Database (NHFD) reports each hospital's attainment of the BPT with other measures, along with reporting outcomes. There is clearly wide variability in provision of orthogerriatrician (OG) services across the dataset. Unfortunately, despite overwhelming evidence that provision of an OG service is of benefit, it is presently challenging to recruit to this important specialty within the UK. Publicly available reports from the NHFD were obtained for each of the 177 participating hospitals for 2017. This was matched with information held within the annual NHFD Facilities Audit for the same period, which include hours of OG support for each hospital. This information was combined with a Freedom of Information request made by email to each hospital for further details concerning OG support. The outcome measures used were Length of Stay (LoS), mortality, and return to usual residence. Comparison was made with provision of OG services by use of Pearson's correlation coefficient. In addition, differences in services were compared between the 25% (44) hospitals delivering outcomes at the extremes for each measure. Attainment of BPT correlated fairly with LoS (−0.48) and to less of a degree with mortality (−0.1) and return home (0.05). Perioperative medical assessment contributed very strongly with BPT attainment (0.75). In turn perioperative medical assessment correlated fairly with LoS (−0.40) and mortality (−0.23) but not return home (0.02). Provision of perioperative medical assessment attainment was correlated fairly with total OG minutes available per new patient (0.22), total OG minutes available per patient per day (0.29) and number of days per week of OG cover (0.34); with no link for number of patients per orthogeriatrician (0.01). Mortality for the best units were associated with 30% more consultant OG time available per patient per day, and 51% more OG time available per patient. Units returning the most patients to their usual residence had little association with OG time, although had 59% fewer patients per OG, the best units had a 19% longer LoS. For all three measures results for the best had on average 0.5 days per week better routine OG access. There is no doubt that good quality care gives better results for this challenging group of patients. However, the interaction of BPT, other care metrics, level of OG support and patient factors with outcomes is complex. We have found OG time available per patient per day appears to influence particularly LoS and mortality. Options to increase OG time per patient include reducing patient numbers (ensuring community osteoporosis/falls prevention in place, including reducing in-patient falls); increasing OG time across the week (employing greater numbers/spreading availability over 7 days per week); and reducing LoS. A reduction in LoS has the largest effect of increasing OG time, and although it is dependent on OG support, it is only fairly correlated with this and many other factors play a part, which could be addressed in units under pressure

Bone turnover and the accumulation of microdamage are impacted by the presence of skeletal metastases which can contribute to increased fracture risk. Treatments for metastatic disease may further impact bone quality. The present study aims to establish a preliminary understanding of microdamage accumulation and load to failure in osteolytic vertebrae following stereotactic body radiotherapy (SBRT), zoledronic acid (ZA), or docetaxel (DTX) treatment. Twenty-two six-week old athymic female rats (Hsd:RH-Foxn1rnu, Envigo, USA) were inoculated with HeLa cervical cancer cells through intracardiac injection (day 0). Institutional approval was obtained for this work and the ARRIVE guidelines were followed. Animals were randomly assigned to four groups: untreated (n=6), spine stereotactic body radiotherapy (SBRT) administered on day 14 (n=6), zoledronic acid (ZA) administered on day 7 (n=5), and docetaxel (DTX) administered on day 14 (n=5). Animals were euthanized on day 21. T13-L3 vertebral segments were collected immediately after sacrifice and stored in −20°C wrapped in saline soaked gauze until testing. µCT scans (µCT100, Scanco, Switzerland) of the T13-L3 segment confirmed tumour burden in all T13 and L2 vertebrae prior to testing. T13 was stained with BaSO. 4. to label microdamage. High resolution µCT scans were obtained (90kVp, 44uA, 4W, 4.9µm voxel size) to visualize stain location and volume. Segmentations of bone and BaSO. 4. were created using intensity thresholding at 3000HU (~736mgHA/cm. 3. ) and 10000HU (~2420mgHA/cm. 3. ), respectively. Non-specific BaSO. 4. was removed from the outer edge of the cortical shell by shrinking the segmentation by 105mm in 3D. Stain volume fraction was calculated as the ratio of BaSO. 4. volume to the sum of BaSO. 4. and bone volume. The L1-L3 motion segments were loaded under axial compression to failure using a µCT compatible loading device (Scanco) and force-displacement data was recorded. µCT scans were acquired unloaded, at 1500µm displacement and post-failure. Stereological analysis was performed on the L2 vertebrae in the unloaded µCT scans. Differences in mean stain volume fraction, mean load to failure, and mean bone volume/total volume (BV/TV) were compared between treatment groups using one-way ANOVAs. Pearson's correlation between stain volume fraction and load to failure by treatment was calculated using an adjusted load to failure divided by BV/TV. Stained damage fraction was significantly different between treatment groups (p=0.0029). Tukey post-hoc analysis showed untreated samples to have higher stain volume fraction (16.25±2.54%) than all treatment groups (p<0.05). The ZA group had the highest mean load to failure (195.60±84.49N), followed by untreated (142.33±53.08N), DTX (126.60±48.75N), and SBRT (95.50±44.96N), but differences did not reach significance (p=0.075). BV/TV was significantly higher in the ZA group (49.28±3.56%) compared to all others. The SBRT group had significantly lower BV/TV than the untreated group (p=0.018). Load divided by BV/TV was not significantly different between groups (p=0.24), but relative load to failure results were consistent (ZA>Untreated>DTX>SBRT). No correlations were found between stain volume fraction and load to failure. Focal and systemic cancer treatments effect microdamage accumulation and load to failure in osteolytic vertebrae. Current testing of healthy controls will help to further separate the effects of the tumour and cancer treatments on bone quality

Bone turnover and the accumulation of microdamage are impacted by the presence of skeletal metastases which can contribute to increased fracture risk. Treatments for metastatic disease may further impact bone quality. The present study aims to establish a preliminary understanding of microdamage accumulation and load to failure in osteolytic vertebrae following stereotactic body radiotherapy (SBRT), zoledronic acid (ZA), or docetaxel (DTX) treatment. Twenty-two six-week old athymic female rats (Hsd:RH-Foxn1rnu, Envigo, USA) were inoculated with HeLa cervical cancer cells through intracardiac injection (day 0). Institutional approval was obtained for this work and the ARRIVE guidelines were followed. Animals were randomly assigned to four groups: untreated (n=6), spine stereotactic body radiotherapy (SBRT) administered on day 14 (n=6), zoledronic acid (ZA) administered on day 7 (n=5), and docetaxel (DTX) administered on day 14 (n=5). Animals were euthanized on day 21. T13-L3 vertebral segments were collected immediately after sacrifice and stored in −20°C wrapped in saline soaked gauze until testing. µCT scans (µCT100, Scanco, Switzerland) of the T13-L3 segment confirmed tumour burden in all T13 and L2 vertebrae prior to testing. T13 was stained with BaSO. 4. to label microdamage. High resolution µCT scans were obtained (90kVp, 44uA, 4W, 4.9µm voxel size) to visualize stain location and volume. Segmentations of bone and BaSO. 4. were created using intensity thresholding at 3000HU (~736mgHA/cm. 3. ) and 10000HU (~2420mgHA/cm. 3. ), respectively. Non-specific BaSO. 4. was removed from the outer edge of the cortical shell by shrinking the segmentation by 105mm in 3D. Stain volume fraction was calculated as the ratio of BaSO. 4. volume to the sum of BaSO. 4. and bone volume. The L1-L3 motion segments were loaded under axial compression to failure using a µCT compatible loading device (Scanco) and force-displacement data was recorded. µCT scans were acquired unloaded, at 1500µm displacement and post-failure. Stereological analysis was performed on the L2 vertebrae in the unloaded µCT scans. Differences in mean stain volume fraction, mean load to failure, and mean bone volume/total volume (BV/TV) were compared between treatment groups using one-way ANOVAs. Pearson's correlation between stain volume fraction and load to failure by treatment was calculated using an adjusted load to failure divided by BV/TV. Stained damage fraction was significantly different between treatment groups (p=0.0029). Tukey post-hoc analysis showed untreated samples to have higher stain volume fraction (16.25±2.54%) than all treatment groups (p<0.05). The ZA group had the highest mean load to failure (195.60±84.49N), followed by untreated (142.33±53.08N), DTX (126.60±48.75N), and SBRT (95.50±44.96N), but differences did not reach significance (p=0.075). BV/TV was significantly higher in the ZA group (49.28±3.56%) compared to all others. The SBRT group had significantly lower BV/TV than the untreated group (p=0.018). Load divided by BV/TV was not significantly different between groups (p=0.24), but relative load to failure results were consistent (ZA>Untreated>DTX>SBRT). No correlations were found between stain volume fraction and load to failure. Focal and systemic cancer treatments effect microdamage accumulation and load to failure in osteolytic vertebrae. Current testing of healthy controls will help to further separate the effects of the tumour and cancer treatments on bone quality

Inter- and intra-observer variation has been noted in the analysis of radiographic examinations with regard to experience of surgeons, and the monitors used for conducting the evaluations. The aim of this study is to evaluate inter/intra observer variation in the measurement of mechanical alignment from long-leg radiographs. 40 patients from the elective waiting list for TKA underwent long leg radiographs pre-operatively and 6 months post-operatively (total of 80 radiographs). The x-rays were analysed by 5 observers ranging in experience from medical student to head orthopaedic surgeon. Two observers re-analysed their results 6 months later to determine intraobserver correlation, and one observer re-measured the alignment on a different monitor. These measurements were all conducted blindly and none of the observers had access to the others’ results. 80 radiographs were analysed in total, 40 pre-op and 40 post-op. The mechanical alignment was analysed using Pearson's correlation (r = 0 no agreement, r = 1 perfect agreement) and revealed that experience as an orthopaedic surgeon has little effect on the measurement of mechanical alignment from long leg radiograph. The results for the different monitor analysis were also analysed using Pearson's correlation of long leg alignment. Monitor quality does seem to affect the correlation between alignment measurements when reviewing both intra and inter observer correlation on different computer monitors. Surgical experience has little impact on the measurement of alignment on long leg radiographs. Of greater concern is that monitors of different resolution can affect measurement of mechanical alignment. As there might be a range of monitors in use in different institutions, and also in outpatient clinics to surgical theatres, close attention should be paid to the implications of these results

The primary aim of this study was to identify the rate of osteoarthritis in scaphoid fracture non-union. We also aimed to investigate whether the incidence of osteoarthritis correlates with the duration of non-union(interval), and to identify the variables that influence the outcome. We retrospectively reviewed 273 scaphoid fracture non-union presented between 2007 and 2016. Data included patient demographics, interval, fracture morphology, grade of osteoarthritis (Kellgren-Lawrence) and scaphoid non-union advanced collapse (SNAC), and overall health-related quality of life. Patients were divided into two groups (SNAC and Non-SNAC). Group differences were analysed using Mann-Whitney U test and association with Pearson's correlations. A two-sided p-value of <0.05 was considered significant. The scaphoid fracture non-union were confirmed on CT scans (n=243) and plain radiographs (n=35). The subjects were 32 females and 260 males with the mean age of 33.8 years (SD, 13.2). The average interval was 3.1 years (range, 0–45 years). Osteoarthritis occurred in 58% (n=161) of non-unions, and 42% (n=117) had no osteoarthritis. In overall, 38.5% (n=107) had SNAC-1, 9% (n=25) with SNAC-2, and 10.4% (n=29) presented with SNAC-3. The mean interval in the non-SNAC group was 1.2 years, and in SNAC 1,2, and 3 were 2.6, 6.8, and 11.1 years, respectively. The average summary index in SNAC and non- SNAC groups was 0.803 and 0.819, respectively. Our results also showed a significant correlation between advanced osteoarthritis and proximal fracture non-unions(P<0.05). We concluded that there is no clear correlation between the interval and the progression of osteoarthritis. SNAC was more likely to occur in fractures aged 2 years or older

Background. Achieving good ligament balance in total knee arthroplasty (TKA) is essential to prevent early failure and revision surgery. Poor balance and instability are well-defined, however, an ideal ligament balance target across all patients is not well-understood. In this study we investigate the achieved ligament balance using an imageless, intra-operative dynamic balancing tool and its relation to patient reported outcomes. Methods. A prospective, multi-surgeon, multi-center study investigated the use of a dynamic ligament-balancing tool in combination with a robotic-assisted navigation platform using the APEX knee (OMNI-Corin, Raynham MA). After all resections, the femoral trial and a computer-controlled tensioning device in place of the tibial tray was inserted into the knee joint. The difference in medial and lateral (ML) gaps when balancing the knee under constant load at extension (10°), mid-flexion (30°) and flexion (90°) was captured. Patients completed the KOOS questionnaire at 3 months ± 2 weeks post-surgery and considered the past 7 days as a timeframe for responses. Pearson's correlation was used to determine linear correlations between factors and ANOVA tests were used to determine differences in categorical data. Results. Thirty patients have currently completed 3 months KOOS questionnaires for analysis (age: 68±9.3yrs, Male: 43%). Strong correlations were found between the difference in ML gap for KOOS symptoms and pain in extension (r=−0.54, p=0.002, r=−0.50, p=0.005, respectively) and mid flexion (r=−0.52, p=0.003, r=−0.48, p=0.007, respectively), but not in full flexion (r=−0.13, p=0.5, r=−0.23, p=0.22, respectively). A threshold of 1.5 mm difference in joint gap under constant load was used to distinguish between balanced and more lax knees medially or laterally. Worse KOOS symptoms were found in patients with tighter lateral laxity in extension and mid flexion (△=15 points, p=0.03, △=21 points, p=0.0002, respectively) compared to the rest of the cohort, see Figure 1. Similarly, worse KOOS pain was found for tight lateral laxity in mid-flexion (△=14 points, p=0.02). No significant differences were found in full flexion or for patients with a tight medial side at any flexion angle. Stronger differences in extension and mid flexion may reflect the type of activities and range of motion most commonly encountered as a TKA patient. A younger population engaging higher demand activities may be more sensitive to coronal soft tissue balance in full flexion. Conclusion. Improved patient outcomes were found to correlate with a neutrally-balanced or tighter medial soft tissue profile compared to tighter lateral structures. These results reflect the behaviour of the native knee. The cohort investigated here is small and data collection is ongoing. Further data will be needed to determine if these results can be generalized and to investigate the potential of patient specificity in ideal ligament balancing. For any figures or tables, please contact authors directly

Introduction. Robotic TKA allows for quantifiable precision performing bone resections for implant realignment within acceptable final component and limb alignments. One of the early steps in this robotic technique is after initial exposure and removal of medial and lateral osteophytes, a “pose-capture” is performed with varus and valgus stress applied to the knee in near full extension and 90° of flexion to assess gaps. Component alignment adjustments can be made on the preoperative plan to balance the gaps. At this point in the procedure any posterior osteophytes will still be present, which could after removal change the flexion and extension gaps by 1–3mm. This must be taken into consideration, or changes in component alignment could result in over-correction of gaps can occur. Objective. The purpose of this study was to identify what effect the posterior osteophyte's size and location and their removal had on gap measurements between pose-capture and after bone cuts are made and gaps assessed during implant trialing. Methods. This was a retrospective, single center cohort study comparing 100 robotic-assisted TKAs. Preoperative computer tomography was assessed for the presence, size and location of posterior osteophytes. Robotic-assessed gaps at pose capture and trialing were collected. Paired t-tests, independent t-tests and Pearson's correlation were used to examine this relationship. Results. Posterior osteophytes were present in 87% of cases with 59.3% isolated to the posterior medial femoral condyle. In the sagittal plane, posterior medial femoral condyle (pMFC), posterior lateral femoral condyle (pLFC) and posterior tibial (pT) osteophytes measured 6.75 ± 2.7mm, 5.77 ± 2.8mm, and 6.52 ± 3.14mm respectively. There was a significant increase in medial (17.4 ± 2.7mm vs 19.7 ± 2.2mm, p<0.01) and lateral (19.2 ± 2.2mm vs 20.5 ± 1.9mm, p<0.01) extension gaps from pose-capture to trialing. There was no difference in the delta of medial extension gaps from pose-change to trialing for knees with pMFC osteophytes > or < 5mm (2.1 ± 2.3 mm vs 2.4 ± 2.1mm, p=0.56). Similarly, there was no difference in the change in lateral extension gaps from pose-capture to trialing for knees with lateral posterior osteophytes > or < 5mm (1.2 ± 2.0mm vs 1.73 ± 1.53mm, p = 0.37). There was no statistically significant correlation between medial or lateral osteophyte size and change in medial (r=0.12, p=0.27) or lateral (r=0.11, p=0.36) extension gaps respectively. Conclusion. While there is a significant change in robotically assessed gaps at pose-capture and trialing, this change is small, our study findings are not able to substantiate that it is solely due to the presence, size or location of posterior osteophytes. A post-hoc power analysis indicates that, in order to detect a difference in gap between pose-capture and trialing of 1mm, over 75 knees with and without posterior osteophytes would be needed

Introduction. Acetabular dysplasia cause hip joint osteoarthritis(OA) by change hip mechanism. However, to our best knowledge, no studies have been published using prospectively collected data from asymptomatic young age volunteers, precise radiographic method. The purpose of this study is to evaluate the prevalence of hip dysplasia in asymptomatic Korean population as one of the most important risk factor of hip OA. Materials & Methods. From December 2014 to March 2015, we investigated prospectively collected retrospectively reviewed data of 200 asymptomatic volunteers 400 hips in age between 18 and 50 years recruited from our institution. Pelvic radiographs were taken and all radiographs were reviewed by 2 experienced orthopedic surgeons. Lateral center-edge angle(LCEA), Sharp angle, Tonnis angle and acetabular width-depth ratio were measured. We analyzed the statistical differences of these values between sex by Mann-Whitney U test and independent t-test. Pearson's correlation coefficient was used to measure the relationship between dysplasia parameters. Results. On the Pelvic AP view, 60 of the 400 hips (15%) were dysplastic hip as LCEA <20°. In 146 male hips, 17 hips (11.6%) were LCEA <20°. In 254 female hips, 43 hips(16.9%) were LCEA <20°. There was no strong correlation of LCEA with other measurements. Conclusion. There are large number of asymptomatic dysplastic hips in Asian population compared previously investigated

One in five patients remain unsatisfied due to ongoing pain and impaired mobility following total knee arthroplasty (TKA). It is important if surgeons can pre-operatively identify which patients may be at risk for poor outcomes after TKA. The purpose of this study was to determine if there is an association between pre-operative measures and post-operative outcomes in patients who underwent TKA. This study included 28 patients (female = 12 / male = 16, age = 63.6 ± 6.9, BMI = 29.9 ± 7.4 kg/m2) with knee osteoarthritis who were scheduled to undergo TKA. All surgeries were performed by the same surgeon (GD), and a subvastus approach was performed for all patients. Patients visited the gait lab within one-month of surgery and 12 months following surgery. At the gait lab, patients completed the knee injury and osteoarthritis outcome score (KOOS), a timed up and go (TUG), and walking task. Variables of interest included the five KOOS sub-scores (symptoms, pain, activities of daily living, sport & recreation, and quality of life), completion time for the TUG, walking speed, and peak knee biomechanics variables (flexion angle, abduction moment, power absorption). A Pearson's product-moment correlation was run to assess the relationship between pre-operative measures and post-operative outcomes in the TKA patients. Preliminary analyses showed the relationship to be linear with all variables normally distributed, as assessed by Shapiro-Wilk's test (p > .05), and there were no outliers. There were no statistically significant correlations between any of the pre-operative KOOS sub-scores and any of the post-operative biomechanical outcomes. Pre-operative TUG time had a statistically significant, moderate positive correlation with post-operative peak knee abduction moments [r(14) = .597, p < .001] and peak knee power absorption [r(14) = .498, p = .007], with pre-operative TUG time explaining 36% of the variability in peak knee abduction moment and 25% of the variability in peak knee power absorption. Pre-operative walking speed had a statistically significant, moderate negative correlation with post-operative peak knee abduction moments [r(14) = -.558, p = .002] and peak knee power absorption [r(14) = -.548, p = .003], with pre-operative walking speed explaining 31% of the variability in peak knee abduction moment and 30% of the variability in peak knee power absorption. Patient reported outcome measures (PROMs), such as the KOOS, do indicate the TKA is generally successful at relieving pain and show an overall improvement. However, their pre-operative values do not correlate with any biomechanical indicators of post-operative success, such as peak knee abduction moment and knee power. Shorter pre-operative TUG times and faster pre-operative walking speeds were correlated with improved post-operative biomechanical outcomes. These are simple tasks surgeons can implement into their clinics to evaluate their patients. Future research should expand these findings to a larger sample size and to determine if other factors, such as surgical approach or implant design, improves patient outcomes

Outsourcing elective surgery has become increasingly commonplace to meet increasing demand from a growing & aging population. There is concern that outsourcing was influencing the nature of residual workload that was unsuitable for treatment elsewhere. This led to the impression that our unit is operating on more complex patients orthopaedic problems, ASA and Body Mass Index (BMI). By losing a disproportionate number of straightforward patients our department's outcomes, productivity and training opportunities could be adversely affected. Retrospective analysis of prospectively collected data of primary hip / knee arthroplasties between July & December for 2014(pre-outsourcing), 2015 and 2016(post-outsourcing). ANOVA, Tukey Honest Significant Difference(HSD) and Pearson's correlation used. Total of 726 primary arthroplasties were performed with an almost 50 % reduction post outsourcing. Post-outsourcing, BMI and ASA were significantly worse with a ANOVA of p=0.001 and HSD p=0.003. Length of stay increased from 5.4 days in 2014 to 6.2 days in 2015 ANOVA p< 0.001 but decreased in 2016. BMI significantly affected operating time (Pearson's r =0.12, p< 0.05) and anaesthetic time (Pearson's r =0.19, p< 0.05). ASA significantly affected length of hospital stay, p< 0.01 and operation time, p=0.007 but no effect on anaesthetic time. In conclusion, we are operating on more complex patients due to current outsourcing setup. Implications for short-term were on anaesthetic and operation time, inpatient stay and training opportunity were affected, with possible long-term implications on individual surgeon and unit outcomes (complications, patient satisfaction)

Purpose. the purpose of this study was to compare the rollback ratio in the bi-cruciate substituting BCS-TKA and the Oxford UKA. Methods. 20 subjects (28 knees) who were performed the BCS-TKA (Journey II: Smith and Nephew) and 24 subjects (29 knees) who were performed the Oxford UKA, were included in this study. Approximately 6 months after surgery, and when the subjects recovered their range of knee motion, following the Laidlow's method (The knee 2010), lateral radiographic imaging of the knee was performed with active full knee flexion. The most posterior tibiofemoral contact point was measured for evaluation of femoral rollback (Rollback ratio). Flexion angle was also measured using the same radiograph and the correlation of rollback and flexion angle was analyzed. As a control, radiographs of the contralateral knees of who were performed Oxford UKA were evaluated (29 knees). Results. The rollback ratios of the BCS-TKA, Oxford UKA, and the control knees were 37.9±4.9%, 35.7±4.2%, and 35.3±4.8% respectively from the posterior edge of the tibia. No significant difference in rollback ratio was observed. The flexion angles of the BCS-TKA, Oxford UKA, and the control knees were 121.8±8.4°, 125.4±7.5°, and 127±10.3°, respectively. No significant difference in knee flexion angle was observed. Significant correlation between rollback ratio and knee flexion angle was observed (p=0.002: Pearson's correlation coefficient =−0.384). Conclusion. In conclusion, BCS-TKA showed no significant difference of rollback ratio when compared with the control knees and the Oxford UKA knees. There is the possibility that the design of BCS-TKA could reproduce the native ACL and PCL function

Traditional medial soft tissue release for balancing of the varus knee in total knee arthroplasty can lead to an inconsistent reduction in medial tension. The purpose of this study is to establish whether sequential needle puncturing of the medial collateral ligament (MCL) can be a safe and predictable method for medial release. Total knee prostheses were implanted in 14 cadaveric specimens by a single surgeon. Medial tension was measured in flexion and extension by a pressure sensor with implants in place, and calipers after removal of implants and gap distraction under constant tension. Measurements were performed after each of 5 sets of 5 punctures of the MCL with an 18-gauge needle and following 5 transverse perforations with an 11-blade. A consistent valgus force was applied after each set of MCL punctures with a pneumatic cylinder. Pearson's correlation was used to compare pressure sensor measurement with gap distance measurement under tension. The pressure as detected by the sensor after each set of 5 punctures was analyzed by a repeated measures two-way ANOVA and a Tukey multiple comparisons test to determine a significant decreases between puncture sets. The pressure sensor device correlated more closely with systematic tissue release (r=0.59 for % change from baseline) than did measurements of gap increase under tension (r= −0.22). All knees had ≤5mm of medial opening with up to 25 needle punctures. Two knees had <5mm of medial opening in flexion after blade perforation. The mean pressure decreases in 90 degrees flexion, mid-flexion and extension were 11.2, 9.4 and 9.9 lbs respectively after 5 needle punctures and 8.1, 11.5 and 9.6 lbs between 5 and 15. Significant pressure decreases were seen after 5 and 10 needle punctures and again after blade perforation (p<0.05). Needle puncture of the deep and superficial MCL leads to a significant and reliable decrease in medial tension over the first 15, with diminishing effect up to 25 punctures. This method may be employed when up to 20 lbs reduction in medial pressure is desired. Blade perforation after needle puncture should be approached with caution

Introduction. Gelsolin (GSN) is a protein whose function in the cytoplasm is to regulate intracellular actin assembly, while circulating plasma GSN has been implicated in the clearance of cellular byproducts via the body's scavenger system. In knee synovial fluid, GSN appears to be protective of inflammation as lower levels have been found in patients with rheumatoid arthritis while higher levels have been demonstrated in hypersensitivity reactions to metallic implants. The purpose of this study is to define the role of GSN in painful total knee arthroplasty (TKA) patients as a biomarker to distinguish septic from aseptic diagnoses. Methods. After Institutional Review Board (IRB) approval, 50 patients were enrolled in the study into two cohorts. 25 patients presented with a painful TKA and 25 patients had a painful native knee with primary osteoarthritis (OA). Synovial fluid was obtained from each patient's affected knee. Appropriate lab and culture data was also obtained from the painful TKA group. An ELISA was used to determine GSN levels and the groups were compared. Two tailed Student's t tests were used to compare means while Pearson's Correlation Coefficient and linear regression analyses were used to determine association between laboratory findings and GSN levels. Results. 11 of 25 knees in the TKA group had culture positive aspirations while the remaining 14 were sterile and determined to have aseptic component loosening. There was a significant difference in the GSN levels of the entire TKA cohort when compared to the OA group (TKA = 41,218 ng/mL; OA = 84,188 ng/mL; p = 0.002), with no difference noted between the infected and sterile TKA patients (infected = 43,210 ng/mL; sterile = 39,654 ng/mL; p = 0.63). There was a high correlation of ESR and CRP to GSN in the infected TKA group (r = 0.66 and 0.93 respectively; [Fig. 1 and 2]). Discussion. GSN levels correlate highly to other commonly used markers of periprosthetic joint infection (PJI), with overall lower levels seen in PJI when compared to patients with OA. However, GSN levels may be indicative of a painful total knee arthroplasty for multiple reasons, and further study is needed to delineate its role as a biomarker of PJI as well as specific aseptic TKA diagnoses

INTRODUCTION. There are many factors which contribute to function after TKA. In this study we focus on the effect of varus-valgus (VV) balancing measured externally. A loose knee can show instability (Sharkey 2014) while too tight, flexion can be limited. Equal lateral-medial balancing at surgery leads to a better result (Unitt 2008; Gustke 2014), which is generally the surgical goal. Indeed similar varus and valgus laxity angles have been found in most studies in vitro (Markolf 2015; Boguszewski 2015) and in vivo (Schultz 2007; Clarke 2016; Heesterbeek 2008). The angular ranges have been 3–5 degrees at 10–15 Nm of knee moment, females having the higher angles. The goal of this study was to measure the varus and valgus laxity, as well as the functional outcome scores, of two cohorts; well-functioning total knees after at least one year follow-up, and subjects with healthy knees in a similar age group to the TKR's. Our hypothesis was that the results will be equal in the two groups. METHODS & MATERIALS. 50 normal subjects average age 66 (27 male, 23 female) and 50 TKA at 1 year follow-up minimum average age 68 years (16 male, 34 female) were recruited in this IRB study. The TKA's were performed by one surgeon (PAM) of one TKA design, balancing by gap equalization. Subjects completed a KSS evaluation form to determine functional, objective, and satisfaction scores. Varus and valgus measurements were made using the Smart Knee Fixture (Figure 1)(Borukhov 2016) at 20 deg flexion with a moment of 10 Nm. RESULTS. The statistical results are summarized in table 1. There was no significant difference in either varus or valgus laxity between the two groups (p= 0.9, 0.3 respectively). Pearson's correlation coefficient between varus and valgus laxity of the healthy group was 0.42, while for the TKA group was 0.55. In both cohorts varus laxity was significant higher than valgus laxity (p= 0.001 for healthy subjects and p=0.0001 for TKA). The healthy group had higher functional and objective KSS scores (p= 0.005, and p=0.004 respectively), but the same satisfaction scores as the TKA (p=0.3) (Table 2). No correlation was found between the total laxity of the TKA group and the KSS scores (functional, objective and satisfaction). Total laxity in females was significantly higher than in males in the healthy group, but no differences was found in the TKA group. DISCUSSION. The hypothesis of equal varus and valgus angles in the 2 groups was supported. The larger varus angle implied a less stiff lateral collateral compared with the medial collateral. If the TKA's were balanced equally at surgery, it is possible there was ligament remodeling over time. However the functional scores were inferior for the TKA compared with normal. This finding has not been highlighted in the literature so far. The causes could include weak musculature (Yoshida 2013), non-physiologic kinematics due to the TKA design, or the use of rigid materials in the TKA. The result presents a challenge to improve outcomes after TKA. For figures/tables, please contact authors directly.

Patients often comment on swelling after foot and ankle surgery. However the relationship between swelling and outcome (pain and function) has not previously been outlined. A recent study by Pinsker and Daniels demonstrated that while swelling was rated as important by patients it was rarely included in outcome scores. The purpose of this paper was to determine the relationship between swelling and outcome after ankle fusion or replacement. A secondary purpose was to determine how this relationship changed in time, how swelling score changed before and after surgery, and determine differences in swelling score between total ankle replacement (TAR), open ankle arthrodesis (OAA) and arthroscopic ankle arthrodesis (AAA). The COFAS prospective ankle arthritis database enrolls patients in 4 centers undergoing surgery by one of 6 surgeons since 2002. The MODEMS outcomes package from AAOS was used, with the validated ankle osteoarthritis score (AOS) score being used to assess outcomes in the pain and disability domains. The swelling score was indexed from 1 to 5, 1 being no swelling and 5 being severe swelling. Outcomes were recorded preoperatively and annually up to 2010. Statistical analysis was performed using 95% confidence intervals and correlations being determined using Pearson's correlation and r2 values. The swelling score was correlated with AOS score with an r2 of 0.13 for postoperative patients. With the swelling score analysed categorically the difference of outcome was significant with a mean AOS score of 15.1 (CI 13.3 to 16.9) for a swelling score of 1, 23 (CI 21.7 to 24.9) for a swelling score of 2, 31 (CI 29.6 to 33.1) for 33.6 (CI 34.9 to 38.8) for 4, and 39 (CI 35.3 to 43.0) for 5. Swelling scores fell outside the 95% confidence intervals for all groups indicating that the AOS outcome of swelling score 5 patients was worse than the 4 group, 4 worse than 3, 3 worse than 2, and 2 worse than 1. Patients with swelling scores of 1 scored 24 points better than those with a swelling score of 5. Swelling scores were the same preoperatively for total ankle arthroplasty, Arthroscopic and open fusions. However swelling scores were lower for arthroscopic fusions after surgery for all time periods at an average of 2.1 (CI 1.9 to 2.2), compared to total ankle arthroplasty (2.5, CI 2.4 to 2.6) and open ankle fusion (2.5, CI 2.4 to 2.6). Swelling has a major relationship with outcome. Swelling may be the cause of poorer outcomes for open ankle fusion compared to arthroscopic. Swelling is an independent factor as swelling scores for TAA were higher compared to AAA despite similar outcomes. Arthroscopic surgery reduces the postoperative swelling. Methods to reduce swelling such as compression stockings, elevation, controlling bleeding may result in better outcomes. Minimising the invasiveness of surgery achieves this goal. Patient education about swelling, elevation and compression stockings would assist in these goals