Aims. Cementing in arthroplasty for hip fracture is associated with improved postoperative function, but may have an increased risk of early mortality compared to uncemented fixation. Quantifying this mortality risk is important in providing safe patient care. This study investigated the association between cement use in arthroplasty and mortality at 30 days and one year in patients aged 50 years and over with hip fracture. Methods. This retrospective cohort study used linked data from the Australian Hip Fracture Registry and the National Death Index. Descriptive analysis and Kaplan-Meier survival curves tested the unadjusted association of mortality between cemented and uncemented procedures. Multilevel logistic regression, adjusted for covariates, tested the association between cement use and 30-day mortality following arthroplasty. Given the known institutional variation in preference for cemented fixation, an instrumental variable analysis was also performed to minimize the effect of unknown confounders. Adjusted Cox modelling analyzed the association between cement use and mortality at 30 days and one year following surgery. Results. The 30-day mortality was 6.9% for cemented and 4.9% for uncemented groups (p = 0.003). Cement use was significantly associated with 30-day mortality in the Kaplan-Meier survival curve (p = 0.003). After adjusting for covariates, no significant association between cement use and 30-day mortality was shown in the adjusted multilevel logistic regression (odd rati0 (OR) 1.1, 95% confidence interval (CI) 0.9 to 1.5; p = 0.366), or in the instrumental variable analysis (OR 1.0, 95% CI 0.9 to 1.0, p=0.524). There was no significant between-group difference in mortality within 30days (hazard ratio (HR) 0.9, 95% CI 0.7to 1.1; p = 0.355) or one year (HR 0.9 95% CI 0.8 to 1.1; p = 0.328) in the Cox modelling. Conclusion. No statistically significant difference in patient mortality with cement use in arthroplasty was demonstrated in this population, once adjusted for covariates. This study concludes that cementing in arthroplasty for hip fracture is a safe means of surgical fixation. Cite this article: Bone Jt Open 2023;4(3):198–204

Aims. The volume of ambulatory total hip arthroplasty (THA) procedures is increasing due to the emphasis on value-based care. The purpose of the study is to identify the causes for failed same-day discharge (SDD) and perioperative factors leading to failed SDD. Methods. This retrospective cohort study followed pre-selected patients for SDD THA from 1 August 2018 to 31 December 2020. Inclusion criteria were patients undergoing unilateral THA with appropriate social support, age 18 to 75 years, and BMI < 37 kg/m. 2. Patients with opioid dependence, coronary artery disease, and valvular heart disease were excluded. Demographics, comorbidities, and perioperative data were collected from the electronic medical records. Possible risk factors for failed SDD were identified using multivariate logistic regression. Results. In all, 278 patients were identified with a mean age of 57.1 years (SD 8.1) and a mean BMI of 27.3 kg/m. 2. (SD 4.5). A total of 96 patients failed SDD, with the most common reasons being failure to clear physical therapy (26%), dizziness (22%), and postoperative nausea and vomiting (11%). Risk factors associated with failed SDD included smokers (odds ratio (OR) 6.24; p = 0.009), a maximum postoperative pain score > 8 (OR 4.76; p = 0.004), and procedures starting after 11 am (OR 2.28; p = 0.015). A higher postoperative tolerable pain goal (numerical rating scale 4 to 10) was found to be associated with successful SDD (OR 2.7; p = 0.001). Age, BMI, surgical approach, American Society of Anesthesiologists grade, and anaesthesia type were not associated with failed SDD. Conclusion. SDD is a safe and viable option for pre-selected patients interested in rapid recovery THA. The most common causes for failure to launch were failing to clear physical thereapy and patient symptomatology. Risk factors associated with failed SSD highlight the importance of preoperative counselling regarding smoking cessation and postoperative pain to set reasonable expectations. Future interventions should aim to improve patient postoperative mobilization, pain control, and decrease symptomatology. Cite this article: Bone Jt Open 2022;3(9):684–691

Aims. Delirium is associated with adverse outcomes following hip fracture, but the prevalence and significance of delirium for the prognosis and ongoing rehabilitation needs of patients admitted from home is less well studied. Here, we analyzed relationships between delirium in patients admitted from home with 1) mortality; 2) total length of hospital stay; 3) need for post-acute inpatient rehabilitation; and 4) hospital readmission within 180 days. Methods. This observational study used routine clinical data in a consecutive sample of hip fracture patients aged ≥ 50 years admitted to a single large trauma centre during the COVID-19 pandemic between 1 March 2020 and 30 November 2021. Delirium was prospectively assessed as part of routine care by the 4 A’s Test (4AT), with most assessments performed in the emergency department. Associations were determined using logistic regression adjusted for age, sex, Scottish Index of Multiple Deprivation quintile, COVID-19 infection within 30 days, and American Society of Anesthesiologists grade. Results. A total of 1,821 patients were admitted, with 1,383 (mean age 79.5 years; 72.1% female) directly from home. Overall, 87 patients (4.8%) were excluded due to missing 4AT scores. Delirium prevalence in the whole cohort was 26.5% (460/1,734): 14.1% (189/1,340) in the subgroup of patients admitted from home, and 68.8% (271/394) in the remaining patients (comprising care home residents and inpatients when fracture occurred). In patients admitted from home, delirium was associated with a 20-day longer total length of stay (p < 0.001). In multivariable analyses, delirium was associated with higher mortality at 180 days (odds ratio (OR) 1.69 (95% confidence interval (CI) 1.13 to 2.54); p = 0.013), requirement for post-acute inpatient rehabilitation (OR 2.80 (95% CI 1.97 to 3.96); p < 0.001), and readmission to hospital within 180 days (OR 1.79 (95% CI 1.02 to 3.15); p = 0.041). Conclusion. Delirium affects one in seven patients with a hip fracture admitted directly from home, and is associated with adverse outcomes in these patients. Delirium assessment and effective management should be a mandatory part of standard hip fracture care. Cite this article: Bone Jt Open 2023;4(6):447–456

Aims. Iliopsoas impingement occurs in 4% to 30% of patients after undergoing total hip arthroplasty (THA). Despite a relatively high incidence, there are few attempts at modelling impingement between the iliopsoas and acetabular component, and no attempts at modelling this in a representative cohort of subjects. The purpose of this study was to develop a novel computational model for quantifying the impingement between the iliopsoas and acetabular component and validate its utility in a case-controlled investigation. Methods. This was a retrospective cohort study of patients who underwent THA surgery that included 23 symptomatic patients diagnosed with iliopsoas tendonitis, and 23 patients not diagnosed with iliopsoas tendonitis. All patients received postoperative CT imaging, postoperative standing radiography, and had minimum six months’ follow-up. 3D models of each patient’s prosthetic and bony anatomy were generated, landmarked, and simulated in a novel iliopsoas impingement detection model in supine and standing pelvic positions. Logistic regression models were implemented to determine if the probability of pain could be significantly predicted. Receiver operating characteristic curves were generated to determine the model’s sensitivity, specificity, and area under the curve (AUC). Results. Highly significant differences between the symptomatic and asymptomatic cohorts were observed for iliopsoas impingement. Logistic regression models determined that the impingement values significantly predicted the probability of groin pain. The simulation had a sensitivity of 74%, specificity of 100%, and an AUC of 0.86. Conclusion. We developed a computational model that can quantify iliopsoas impingement and verified its accuracy in a case-controlled investigation. This tool has the potential to be used preoperatively, to guide decisions about optimal cup placement, and postoperatively, to assist in the diagnosis of iliopsoas tendonitis. Cite this article: Bone Jt Open 2023;4(1):3–12

Aims. This study aims to assess the relationship between history of pseudotumour formation secondary to metal-on-metal (MoM) implants and periprosthetic joint infection (PJI) rate, as well as establish ESR and CRP thresholds that are suggestive of infection in these patients. We hypothesized that patients with a pseudotumour were at increased risk of infection. Methods. A total of 1,171 total hip arthroplasty (THA) patients with MoM articulations from August 2000 to March 2014 were retrospectively identified. Of those, 328 patients underwent metal artefact reduction sequence MRI and had minimum two years’ clinical follow-up, and met our inclusion criteria. Data collected included demographic details, surgical indication, laterality, implants used, history of pseudotumour, and their corresponding preoperative ESR (mm/hr) and CRP (mg/dl) levels. Multivariate logistic regression modelling was used to evaluate PJI and history of pseudotumour, and receiver operating characteristic curves were created to assess the diagnostic capabilities of ESR and CRP to determine the presence of infection in patients undergoing revision surgery. Results. The rate of PJI for all identified MoM THAs was 3.5% (41/1,171), with a mean follow-up of 10.9 years (2.0 to 20.4). Of the patients included in the final cohort, 8.2% (27/328) had PJI, with a mean follow-up of 12.2 years (2.3 to 20.4). Among this cohort, 31.1% (102/328) had a history of pseudotumour. The rate of PJI in these patients was 14.7% (15/102), which was greater than those without pseudotumour, 5.3% (12/226) (p = 0.008). Additionally, logistic regression analysis showed an association between history of pseudotumour and PJI (odds ratio 4.36 (95% confidence interval 1.77 to 11.3); p = 0.002). Optimal diagnostic cutoffs for PJI in patients with history of pseudotumour versus those without were 33.1 mm/hr and 24.5 mm/hr for ESR and 7.37 mg/dl and 1.88 mg/dl for CRP, respectively. Conclusion. Patients with history of pseudotumour secondary to MoM THA had a higher likelihood of infection than those without. While suspicion of infection should be high for these patients, ESR and CRP cutoffs published by the European Bone and Joint Infection Society may not be appropriate for patients with a history of pseudotumour, as ESR and CRP levels suggestive of PJI are likely to be higher than for those without a pseudotumour. Additional investigation, such as aspiration, is highly recommended for these patients unless clinical suspicion and laboratory markers are low. Cite this article: Bone Joint J 2024;106-B(6):555–564

Aims. Navigation devices are designed to improve a surgeon’s accuracy in positioning the acetabular and femoral components in total hip arthroplasty (THA). The purpose of this study was to both evaluate the accuracy of an optical computer-assisted surgery (CAS) navigation system and determine whether preoperative spinopelvic mobility (categorized as hypermobile, normal, or stiff) increased the risk of acetabular component placement error. Methods. A total of 356 patients undergoing primary THA were prospectively enrolled from November 2016 to March 2018. Clinically relevant error using the CAS system was defined as a difference of > 5° between CAS and 3D radiological reconstruction measurements for acetabular component inclination and anteversion. Univariate and multiple logistic regression analyses were conducted to determine whether hypermobile (. Δ. sacral slope(SS). stand-sit. > 30°), or stiff (. ∆. SS. stand-sit. < 10°) spinopelvic mobility contributed to increased error rates. Results. The paired absolute difference between CAS and postoperative imaging measurements was 2.3° (standard deviation (SD) 2.6°) for inclination and 3.1° (SD 4.2°) for anteversion. Using a target zone of 40° (± 10°) (inclination) and 20° (± 10°) (anteversion), postoperative standing radiographs measured 96% of acetabular components within the target zone for both inclination and anteversion. Multiple logistic regression analysis controlling for BMI and sex revealed that hypermobile spinopelvic mobility significantly increased error rates for anteversion (odds ratio (OR) 2.48, p = 0.009) and inclination (OR 2.44, p = 0.016), whereas stiff spinopelvic mobility increased error rates for anteversion (OR 1.97, p = 0.028). There were no dislocations at a minimum three-year follow-up. Conclusion. Despite high reliability in acetabular positioning for inclination in a large patient cohort using an optical CAS system, hypermobile and stiff spinopelvic mobility significantly increased the risk of clinically relevant errors. In patients with abnormal spinopelvic mobility, CAS systems should be adjusted for use to avoid acetabular component misalignment and subsequent risk for long-term dislocation. Cite this article: Bone Jt Open 2022;3(6):475–484

Aims. The main aims were to identify risk factors predictive of a radiolucent line (RLL) around the acetabular component with an interface bioactive bone cement (IBBC) technique in the first year after THA, and evaluate whether these risk factors influence the development of RLLs at five and ten years after THA. Methods. A retrospective review was undertaken of 980 primary cemented THAs in 876 patients using cemented acetabular components with the IBBC technique. The outcome variable was any RLLs that could be observed around the acetabular component at the first year after THA. Univariate analyses with univariate logistic regression and multivariate analyses with exact logistic regression were performed to identify risk factors for any RLLs based on radiological classification of hip osteoarthritis. Results. RLLs were detected in 27.2% of patients one year postoperatively. In multivariate regression analysis controlling for confounders, atrophic osteoarthritis (odds ratio (OR) 2.17 (95% confidence interval (CI), 1.04 to 4.49); p = 0.038) and 26 mm (OR 3.23 (95% CI 1.85 to 5.66); p < 0.001) or 28 mm head diameter (OR 3.64 (95% CI 2.07 to 6.41); p < 0.001) had a significantly greater risk for any RLLs one year after surgery. Structural bone graft (OR 0.19 (95% CI 0.13 to 0.29) p < 0.001) and location of the hip centre within the true acetabular region (OR 0.15 (95% CI 0.09 to 0.24); p < 0.001) were significantly less prognostic. Improvement of the cement-bone interface including complete disappearance and poorly defined RLLs was identified in 15.1% of patients. Kaplan-Meier survival analysis for the acetabular component at ten years with revision of the acetabular component for aseptic loosening as the end point was 100.0% with a RLL and 99.1% without a RLL (95% CI 97.9 to 100). With revision of the acetabular component for any reason as the end point, the survival rate was 99.2% with a RLL (95% CI 97.6 to 100) and 96.5% without a RLL (95% CI 93.4 to 99.7). Conclusion. This study demonstrates that acetabular bone quality, head diameter, structural bone graft, and hip centre position may influence the presence of the any RLL. Cite this article: Bone Joint Open 2021;2(5):278–292

Aims. We evaluated a large database with mechanical failure of a single uncemented modular femoral component, used in revision hip arthroplasty, as the end point and compared them to a control group treated with the same implant. Patient- and implant-specific risk factors for implant failure were analyzed. . Methods. All cases of a fractured uncemented modular revision femoral component from one manufacturer until April 2017 were identified and the total number of implants sold until April 2017 was used to calculate the fracture rate. The manufacturer provided data on patient demographics, time to failure, and implant details for all notified fractured devices. Patient- and implant-specific risk factors were evaluated using a logistic regression model with multiple imputations and compared to data from a previously published reference group, where no fractures had been observed. The results of a retrieval analysis of the fractured implants, performed by the manufacturer, were available for evaluation. Results. There were 113 recorded cases with fracture at the modular junction, resulting in a calculated fracture rate of 0.30% (113/37,600). The fracture rate of the implant without signs of improper use was 0.11% (41/37,600). In 79% (89/113) of cases with a failed implant, either a lateralized (high offset) neck segment, an extralong head, or the combination of both were used. Logistic regression analysis revealed male sex, high body mass index (BMI), straight component design, and small neck segments were significant risk factors for failure. Investigation of the implants (76/113) showed at least one sign of improper use in 72 cases. Conclusion. Implant failure at the modular junction is associated with patient- and implant-specific risk factors as well as technical errors during implantation. Whenever possible, the use of short and lateralized neck segments should be avoided with this revision system. Implantation instructions and contraindications need to be adhered to and respected. Cite this article: Bone Joint J 2020;102-B(5):573–579

Aims. Transfusion after primary total hip arthroplasty (THA) has become rare, and identification of causative factors allows preventive measures. The aim of this study was to determine patient-specific factors that increase the risk of needing a blood transfusion. Methods. All patients who underwent elective THA were analyzed retrospectively in this single-centre study from 2020 to 2021. A total of 2,892 patients were included. Transfusion-related parameters were evaluated. A multiple logistic regression was performed to determine whether age, BMI, American Society of Anesthesiologists (ASA) grade, sex, or preoperative haemoglobin (Hb) could predict the need for transfusion within the examined patient population. Results. The overall transfusion rate was 1.2%. Compared to the group of patients without blood transfusion, the transfused group was on average older (aged 73.8 years (SD 9.7) vs 68.6 years (SD 10.1); p = 0.020) and was mostly female (p = 0.003), but showed no significant differences in terms of BMI (28.3 kg/m. 2. (SD 5.9) vs 28.7 kg/m. 2. (SD 5.2); p = 0.720) or ASA grade (2.2 (SD 0.5) vs 2.1 (SD 0.4); p = 0.378). The regression model identified a cutoff Hb level of < 7.6 mmol/l (< 12.2 g/dl), aged > 73 years, and a BMI of 35.4 kg/m² or higher as the three most reliable predictors associated with postoperative transfusion in THA. Conclusion. The possibility of transfusion is predictable based on preoperatively available parameters. The proposed thresholds for preoperative Hb level, age, and BMI can help identify patients and take preventive measures if necessary. Cite this article: Bone Jt Open 2024;5(7):560–564

The ‘Best Practice Tariff‘ (BPT) was developed to improve hip fracture care by incentivising hospitals to provide timely multidisciplinary care to patients sustaining these injuries. The current literature examining the association between BPT and patient outcomes is conflicting and underpowered. We aimed to determine if achieving BPT has an impact on 30-day mortality and postoperative length of stay. A retrospective analysis for patients admitted to a major trauma centre (MTC) was performed between 01/01/2013 to 31/12/2020. Data were extracted from the National Hip Fracture Database. The study population was divided into two groups: those who achieved all BPT criteria (BPT-passed) and those who did not (BPT-failed). The primary outcomes of interest included the 30-day mortality rate and postoperative length of stay (LOS). As a secondary objective, we aimed to assess factors that predict perioperative mortality by utilising a logistic regression model. 4397 cases were included for analysis. 3422 (78%) met the BPT criteria, whereas 973 (22%) did not. The mean LOS in the BPT-achieving group was 17.2 days compared with 18.6 in the BPT-failed group, p<0.001. 30-day mortality was significantly lower in the BPT-achieving group i.e., 4.3% in BPT-achieved vs. 12.1% in BPT-failed, p<0.001. Logistic regression modelling demonstrated that attainment of BPT was associated with significantly lower 30-day mortality (OR: 0.32; 95% CI:0.24–0.41; p<0.001). To our knowledge, this is the largest study to investigate the association between BPT attainment and 30-day mortality as well as the length of stay. The present study demonstrates that achieving BPT in hip fracture patients is associated with a significant reduction in the average length of stay and 30-day mortality rates. Our crude calculations revealed that achieving BPT for 3422 patients earned our hospital trust >£4 million over 8 years. Findings from this study suggest that achieving BPT not only improves 30-day survival in patients with hip fractures but also aids cost-effectiveness by reducing LOS and helps generate NHS Trusts a significant amount of financial reward

Aims. Total hip arthroplasty (THA) is a common procedure to address pain and enhance function in hip disorders such as osteoarthritis. Despite its success, postoperative patient recovery exhibits considerable heterogeneity. This study aimed to investigate whether patients follow distinct pain trajectories following THA and identify the patient characteristics linked to suboptimal trajectories. Methods. This retrospective cohort study analyzed THA patients at a large academic centre (NYU Langone Orthopedic Hospital, New York, USA) from January 2018 to January 2023, who completed the Patient-Reported Outcomes Measurement Information System (PROMIS) pain intensity questionnaires, collected preoperatively at one-, three-, six-, 12-, and 24-month follow-up times. Growth mixture modelling (GMM) was used to model the trajectories. Optimal model fit was determined by Bayesian information criterion (BIC), Vuong-Lo-Mendell-Rubin likelihood ratio test (VLMR-LRT), posterior probabilities, and entropy values. Association between trajectory groups and patient characteristics were measured by multinomial logistic regression using the three-step approach. Results. Among the 1,249 patients, a piecewise GMM model revealed three distinct pain trajectory groups: 56 patients (4.5%) in group 1; 1,144 patients (91.6%) in group 2; and 49 patients (3.9%) in group 3. Patients in group 2 experienced swift recovery post-THA and minimal preoperative pain. In contrast, groups 1 and 3 initiated with pronounced preoperative pain; however, only group 3 exhibited persistent long-term pain. Multinomial regression indicated African Americans were exceedingly likely to follow trajectory groups 1 (odds ratio (OR) 2.73) and 3 (OR 3.18). Additionally, odds of membership to group 3 increased by 12% for each BMI unit rise, by 19% for each added postoperative day, and by over four if discharged to rehabilitation services (OR 4.07). Conclusion. This study identified three distinct pain trajectories following THA, highlighting the role of individual patient factors in postoperative recovery. This emphasizes the importance of preoperatively addressing modifiable risk factors associated with suboptimal pain trajectories, particularly in at-risk patients. Cite this article: Bone Jt Open 2024;5(3):174–183

Aims. Custom flange acetabular components (CFACs) are a patient-specific option for addressing large acetabular defects at revision total hip arthroplasty (THA), but patient and implant characteristics that affect survivorship remain unknown. This study aimed to identify patient and design factors related to survivorship. Patients and Methods. A retrospective review of 91 patients who underwent revision THA using 96 CFACs was undertaken, comparing features between radiologically failed and successful cases. Patient characteristics (demographic, clinical, and radiological) and implant features (design characteristics and intraoperative features) were collected. There were 74 women and 22 men; their mean age was 62 years (31 to 85). The mean follow-up was 24.9 months (. sd. 27.6; 0 to 116). Two sets of statistical analyses were performed: 1) univariate analyses (Pearson’s chi-squared and independent-samples Student’s t-tests) for each feature; and 2) bivariable logistic regressions using features identified from a random forest analysis. Results. Radiological failure and revision rates were 23% and 12.5%, respectively. Revisions were undertaken at a mean of 25.1 months (. sd. 26.4) postoperatively. Patients with radiological failure were younger at the time of the initial procedure, were less likely to have a diagnosis of primary osteoarthritis (OA), were more likely to have had ischial screws in previous surgery, had fewer ischial screw holes in their CFAC design, and had more proximal ischial fixation. Random forest analysis identified the age of the patient and the number of locking and non-locking screws used for inclusion in subsequent bivariable logistic regression, but only age (odds ratio 0.93 per year) was found to be significant. Conclusion. We identified both patient and design features predictive of CFAC survivorship. We found a higher rate of failure in younger patients, those whose primary diagnosis was not OA, and those with more proximal ischial fixation or fewer ischial fixation options. Cite this article: Bone Joint J 2019;101-B(6 Supple B):68–76

Aims. The aims of this study were to determine the incidence and factors for developing periprosthetic joint infection (PJI) following hemiarthroplasty (HA) for hip fracture, and to evaluate treatment outcome and identify factors associated with treatment outcome. Methods. A retrospective review was performed of consecutive patients treated for HA PJI at a tertiary referral centre with a mean 4.5 years’ follow-up (1.6 weeks to 12.9 years). Surgeries performed included debridement, antibiotics, and implant retention (DAIR) and single-stage revision. The effect of different factors on developing infection and treatment outcome was determined. Results. A total of 1,984 HAs were performed during the study period, and 44 sustained a PJI (2.2%). Multiple logistic regression analysis revealed that a higher CCI score (odds ratio (OR) 1.56 (95% confidence interval (CI) 1.117 to 2.187); p = 0.003), peripheral vascular disease (OR 11.34 (95% CI 1.897 to 67.810); p = 0.008), cerebrovascular disease (OR 65.32 (95% CI 22.783 to 187.278); p < 0.001), diabetes (OR 4.82 (95% CI 1.903 to 12.218); p < 0.001), moderate-to-severe renal disease (OR 5.84 (95% CI 1.116 to 30.589); p = 0.037), cancer without metastasis (OR 6.42 (95% CI 1.643 to 25.006); p = 0.007), and metastatic solid tumour (OR 15.64 (95% CI 1.499 to 163.087); p = 0.022) were associated with increasing PJI risk. Upon final follow-up, 17 patients (38.6%) failed initial treatment and required further surgery for HA PJI. One-year mortality was 22.7%. Factors associated with treatment outcome included lower preoperative Hgb level (97.9 g/l (SD 11.4) vs 107.0 g/l (SD 16.1); p = 0.009), elevated CRP level (99.1 mg/l (SD 63.4) vs 56.6 mg/l (SD 47.1); p = 0.030), and type of surgery. There was lower chance of success with DAIR (42.3%) compared to revision HA (66.7%) or revision with conversion to total hip arthroplasty (100%). Early-onset PJI (≤ six weeks) was associated with a higher likelihood of treatment failure (OR 3.5 (95% CI 1.2 to 10.6); p = 0.007) along with patients treated by a non-arthroplasty surgeon (OR 2.5 (95% CI 1.2 to 5.3); p = 0.014). Conclusion. HA PJI initially treated with DAIR is associated with poor chances of success and its value is limited. We strongly recommend consideration of a single-stage revision arthroplasty with cemented components. Cite this article: Bone Jt Open 2022;3(12):924–932

Introduction. Trunnion wear has been reported as a cause for failure of modern total hip replacement implants. While there are several reports on the prevalence of trunnion corrosion with specific stem designs, little is known about the prevalence of this problem across other femoral stem designs. The purpose of this study is to review three commonly used uncemented femoral stems and to correlate any established risk factors with rates of revision. Methods. We reviewed all patients followed prospectively over a 15-year period (March 2000 to September 2015) who underwent total hip arthroplasty with one of three modern uncemented femoral stem designs. All of the stems were made of titanium (Ti. 6. Al. 4. V alloy) with a 12/14 taper design. We included only metal (cobalt chromium) on highly cross-linked polyethylene articulations. We evaluated age, gender, body mass index (BMI), femoral head size, head length, neck angle and offset as potential risk factors for all cause revision and revision excluding infection by univariate analysis. We performed a logistic regression analysis with odds ratios (OR) for each parameter for both all cause revision as well as with infection excluded. We used a p value of <0.05 as a level of significance. Results. A total of 2095 patients were included during the study period and had a minimum three-year follow-up. There were no differences in age, gender, or BMI across the three femoral component groups. There were no cases of trunnion wear or corrosion (with or without an associated adverse local tissue reaction) requiring revision identified across all three stem groups. Univariate logistic regression analysis demonstrated that head size was associated with increased risk of both all cause revision and revision excluding infection. Age, BMI, gender, offset and neck angle did not have significant association to all cause revision or to revisions excluding infection (p>0.05). Multivariate logistic regression controlling for age and BMI demonstrated that a femoral head size less than 32mm was associated with increased likelihood of all cause revision rates (OR 4.60 (95%CI 1.8, 11.8)) and revision excluding infection (OR 4.94 (95%CI 1.7, 14.41). Conclusions. None of the patients who received one of the three modern uncemented femoral stem designs in this cohort demonstrated trunnion wear or corrosion requiring revision for adverse local soft tissue reactions. We recognize that low-levels of corrosion might exist in this cohort and therefore continued follow-up of these patients is required. For any tables or figures, please contact the authors directly

Aims. Rotational acetabular osteotomy (RAO) has been reported to be effective in improving symptoms and preventing osteoarthritis (OA) progression in patients with mild to severe develomental dysplasia of the hip (DDH). However, some patients develop secondary OA even when the preoperative joint space is normal; determining who will progress to OA is difficult. We evaluated whether the preoperative cartilage condition may predict OA progression following surgery using T2 mapping MRI. Methods. We reviewed 61 hips with early-stage OA in 61 patients who underwent RAO for DDH. They underwent preoperative and five-year postoperative radiological analysis of the hip. Those with a joint space narrowing of more than 1 mm were considered to have 'OA progression'. Preoperative assessment of articular cartilage was also performed using 3T MRI with the T2 mapping technique. The region of interest was defined as the weightbearing portion of the acetabulum and femoral head. Results. There were 16 patients with postoperative OA progression. The T2 values of the centre to the anterolateral region of the acetabulum and femoral head in the OA progression cases were significantly higher than those in patients without OA progression. The preoperative T2 values in those regions were positively correlated with the narrowed joint space width. The receiver operating characteristic analysis revealed that the T2 value of the central portion in the acetabulum provided excellent discrimination, with OA progression patients having an area under the curve of 0.858. Furthermore, logistic regression analysis showed T2 values of the centre to the acetabulum’s anterolateral portion as independent predictors of subsequent OA progression (p < 0.001). Conclusion. This was the first study to evaluate the relationship between intra-articular degeneration using T2 mapping MRI and postoperative OA progression. Our findings suggest that preoperative T2 values of the hip can be better prognostic factors for OA progression than radiological measures following RAO. Cite this article: Bone Joint J 2021;103-B(9):1472–1478

Aims. Although there is increasing legalization of the use of cannabis in the USA, few well-powered studies have evaluated the association between cannabis use disorder and outcomes following primary total hip arthroplasty (THA). Thus, the aim of this study was to determine whether patients who use cannabis and undergo primary THA have higher rates of in-hospital length of stay (LOS), medical complications, implant-related complications, and costs. Methods. Using an administrative database, patients with cannabis use disorder undergoing primary THA were matched to a control group in a 1:5 ratio by age, sex, and various medical comorbidities. This yielded 23,030 patients (3,842 in the study group matched with 19,188 in the control group). The variables which were studied included LOS, 90-day medical complications, two-year implant-related complications, and 90-day costs of care. Mann-Whitney U tests were used to compare LOS and costs. Multivariate logistic regression analyses were used to calculate the odds ratios (ORs) of developing complications. Results. We found that patients in the study group had a significantly longer mean LOS compared with the controls (four days vs three days; p < 0.0001).The study group also had a significantly higher incidence and odds of developing medical (23.0 vs 9.8%, OR 1.6; p < 0.0001) and implant-related complications (16 vs 7.4%, OR 1.6; p < 0.0001) and incurred significantly higher mean 90-day costs ($16,938.00 vs $16,023.00; p < 0.0001). Conclusion. With the increasing rates of cannabis use, these findings allow orthopaedic surgeons and other healthcare professionals to counsel patients with cannabis use disorder about the possible outcomes following their THA, with increased hospital stays, complications, and costs. Cite this article: Bone Joint J 2021;103-B(7 Supple B):111–115

Aims. Postoperative delirium (POD) and postoperative cognitive decline (POCD) are common surgical complications. In the UK, the Best Practice Tariff incentivizes the screening of delirium in patients with hip fracture. Further, a National Hip Fracture Database (NHFD) performance indicator is the reduction in the incidence of POD. To aid in its recognition, we sought to determine factors associated with POD and POCD in patients with hip fractures. Methods. We interrogated the NHFD data on patients presenting with hip fractures to our institution from 2016 to 2018. POD was determined using the 4AT score, as recommended by the NHFD and UK Department of Health. POCD was defined as a decline in Abbreviated Mental Test Score (AMTS) of two or greater. Using logistic regression, we adjusted for covariates to identify factors associated with POD and POCD. Results. Of the 1,224 patients presenting in the study period, 1,023 had complete datasets for final analysis. POD was observed in 242 patients (25%). On multivariate analysis only preoperative AMTS and American Society of Anesthesiologists grade (ASA) were independent predictors of POD. Every point increase in AMTS was associated with a fall in the odds of POD by a factor of 0.60 (95% confidence interval (CI) 0.56 to 0.63, p < 0.001). Every grade increase in ASA led to a 1.7-fold increase in the odds of POD (95% CI 1.13 to 2.50, p = 0.009). A preoperative AMTS of less than 8 was strongly predictive of POD with area under the receiver operating characteristic of 0.86 (95% CI 0.84 to 0.89). Only ASA was predictive of POCD—every grade increase in ASA led to a 2.6-fold increase in the odds of POCD (95% CI 1.7 to 4.0, p < 0.001). Conclusion. POD and POCD are common in the hip fracture patients. Preoperative AMTS and ASA are strong predictors of POD, and ASA predictive of POCD. This may aid in the earlier identification of those most at risk and suited for the patient consent and decision-making process. Cite this article: Bone Joint J 2020;102-B(12):1675–1681

In-hospital length of stay (LOS) and discharge disposition following arthroplasty could act as surrogate measures for improvement in patient pathways, and have major cost saving implications for healthcare providers. With the ever-growing adoption of robotic technology in arthroplasty, we wished to evaluate its impact on LOS. The objectives of this study were to compare LOS and discharge disposition following robotic-arm assisted (RO THA) versus conventional technique Total Hip Arthroplasty (CO THA). This large-scale, single institution study included patients of any age undergoing primary THA (N = 1,732) for any cause between May 2019 and January 2023. Data extracted included patient demographics, LOS, need for Post Anaesthesia Care Unit (PACU) admission, anaesthesia type, readmission within 30 days and discharge dispositions. Univariate and multivariate logistic regression models were also employed to identify factors and patient characteristics related to delayed discharge. The median LOS in the RO THA group was 54 hours (34, 78) versus 60 (51, 100) in the CO THA group, p<0.001. Discharge disposition was comparable between the two groups. In the multivariate model, age, need for PACU admission, ASA score > 2, female gender, general anaesthesia and utilisation of the conventional technique were significantly associated with LOS > 2 days. Our study showed that robotic-arm assistance was associated with a shorter LOS in patients undergoing primary THA and no difference in discharge destination. Our results suggest that robotic-arm assistance could be advantageous in partly addressing the upsurge of hip arthroplasty procedures and the concomitant health care burden; however, this needs to be corroborated by long-term cost effectiveness analyses and data from randomised controlled studies

The stem design in total hip arthroplasty (THA) is constantly evolving. The impact of the collar on the risk of periprosthetic fracture remains controversial. This study aimed to determine whether adding a collar to the femoral stem impacts the early periprosthetic fracture risk within 90 days of surgery. This retrospective study included 1,623 patients who underwent primary total hip arthroplasty in a single orthopedic department between January 2010 and December 2020. The inclusion criteria were uncemented stem with or without a collar, in a primary intention, without previous hip surgery with a similar “corail like” design. The assessed data were demographic characteristics (age, gender, number of obese (BMI > 30)), single or dual mobility, the surgical approach, the early complication, particularly the periprosthetic femoral fractures. Of the 1,623 patients, 1,380 received a collared stem (85%), and 243 received a collarless stem (15%). A multivariate analysis was performed to determine the collar's effect on the risk of early periprosthetic fracture (<90 days). Nine (0.55%) early periprosthetic fractures were identified in the whole cohort. There were four fractures (1.65%) in the collarless stem group and five fractures (0.36%) in the collared stem group (p=0,005). One patient required revision surgery in the collared stem group, while two patients required revision surgery in the collarless stem group. The multinomial logistic regression model indicated a statistically significant lower (p<0.05) risk of early periprosthetic fracture within 90 days of surgery in the collared stems group. No other risk factor for early periprosthetic fractures has been identified. Using collared stems in cementless THA protects early periprosthetic femoral fractures within 90 days of surgery

There is still no clear consensus regarding which cup position might provide better functional performance for developmental dysplasia of the hip (DDH). This study aimed to evaluated the feasibility and efficacy of acetabular mirroring reconstruction for DDH in total hip arthroplasty (THA). The study reviewed 96 patients (96 hips) with unilateral Crowe type-II/III DDH undergoing either visualized navigation-assisted mirroring reconstruction with augment according to the rotation center and biomechanical structure of the contralateral normal hips (Mirroring group, 51 hips) or high hip center reconstruction (HHC group, 45 hips) in THA from 2020 to 2023. The functional and radiographic results were analyzed between the groups during a mean follow-up period of 27.5 and 28.9 months (a minimum follow-up of 12 months). The Harris hip score at the last follow-up significantly improved in both groups, while it was significantly higher in the mirroring group (P<0.001). In the HHC group, the rotation center height and greater trochanter height were significantly increased in the affected hip (P<0.001; P<0.001) and the abductor lever arm was significantly decreased in the affected hip compared to that in the contralateral normal hip (P<0.001), whereas in the mirroring group no significant statistical differences were observed between two sides. The limping occurred in 7 patients (13.7%) in the mirroring group and 14 patients (31.1%) in the HHC group (P=0.040). A multiple logistic regression demonstrated mirroring reconstruction could reduce the incidence of postoperative limping (P=0.020). Both mirroring and HHC reconstruction could improve the functional performance of THA, whereas mirroring reconstruction could offer superior biomechanical results and gait improvement as compared with HHC reconstruction, meeting the higher requirements of functional recovery