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

Aims. Septic arthritis of the hip often leads to irreversible osteoarthritis (OA) and the requirement for total hip arthroplasty (THA). The aim of this study was to report the mid-term risk of any infection, periprosthetic joint infection (PJI), aseptic revision, and reoperation in patients with a past history of septic arthritis who underwent THA, compared with a control group of patients who underwent THA for OA. Methods. We retrospectively identified 256 THAs in 244 patients following septic arthritis of the native hip, which were undertaken between 1969 and 2016 at a single institution. Each case was matched 1:1, based on age, sex, BMI, and year of surgery, to a primary THA performed for OA. The mean age and BMI were 58 years (35 to 84) and 31 kg/m. 2. (18 to 48), respectively, and 100 (39%) were female. The mean follow-up was 11 years (2 to 39). Results. The ten-year survival free of any infection was 91% and 99% in the septic arthritis and OA groups, respectively (hazard ratio (HR) = 13; p < 0.001). The survival free of PJI at ten years was 93% and 99% in the septic arthritis and OA groups, respectively (HR = 10; p = 0.002). There was a significantly higher rate of any infection at ten years when THA was undertaken within five years of the diagnosis of septic arthritis compared with those in whom THA was undertaken > five years after this diagnosis was made (14% vs 5%, respectively; HR = 3.1; p = 0.009), but there was no significant difference in ten-year survival free of aseptic revision (HR = 1.14; p = 0.485). The mean Harris Hip Scores at two and five years postoperatively were significantly lower in the septic arthritis group compared with the OA group (p = 0.001 for both). Conclusion. There was a ten-fold increased risk of PJI in patients with a history of septic arthritis who underwent THA compared with those who underwent THA for OA with a ten-year cumulative incidence of 7%. The risk of any infection had a strong downward trend as the time interval between the diagnosis of septic arthritis and THA increased, highlighted by a 3.1-fold higher risk when THAs were performed within five years of the diagnosis being made. Cite this article: Bone Joint J 2022;104-B(2):227–234

Aims. The Forgotten Joint Score-12 (FJS-12) is a validated patient-reported outcome measure (PROM) tool designed to assess artificial prosthesis awareness during daily activities following total hip arthroplasty (THA). The patient-acceptable symptom state (PASS) is the minimum cut-off value that corresponds to a patient’s satisfactory state-of-health. Despite the validity and reliability of the FJS-12 having been previously demonstrated, the PASS has yet to be clearly defined. This study aims to define the PASS of the FJS-12 following primary THA. Methods. We retrospectively reviewed all patients who underwent primary elective THA from 2019 to 2020, and answered both the FJS-12 and the Hip Disability and Osteoarthritis Outcome Score, Joint Replacement (HOOS, JR) questionnaires one-year postoperatively. HOOS, JR score was used as the anchor to estimate the PASS of FJS-12. Two statistical methods were employed: the receiver operating characteristic (ROC) curve point, which maximized the Youden index; and 75th percentile of the cumulative percentage curve of patients who had the HOOS, JR score difference larger than the cut-off value. Results. This study included 780 patients. The mean one-year FJS-12 score was 65.42 (SD 28.59). The mean one-year HOOS, JR score was 82.70 (SD 16.57). A high positive correlation between FJS-12 and HOOS, JR was found (r = 0.74; p<0.001), making the HOOS, JR a valid external anchor. The threshold score of the FJS-12 that maximized the sensitivity and specificity for detecting a PASS was 66.68 (area under the curve = 0.8). The cut-off score value computed with the 75th percentile approach was 92.20. Conclusion. The PASS threshold for the FJS-12 at one year following primary THA was 66.68 and 92.20 using the ROC curve and 75th percentile approaches, respectively. These values can be used to achieve consensus about meaningful postoperative improvement to maximize the utility of the FJS-12 to evaluate and counsel patients undergoing THA. Cite this article: Bone Jt Open 2022;3(4):307–313

Aims. This study aims to answer the following questions in patients with hip osteoarthritis (OA) who underwent total hip arthroplasty (THA): are patient-reported outcome measures (PROMs) affected by the location of the maximum severity of pain?; are PROMs affected by the presence of non-groin pain?; are PROMs affected by the severity of pain?; and are PROMs affected by the number of pain locations?. Methods. We reviewed 336 hips (305 patients) treated with THA for hip OA from December 2016 to November 2019 using pain location/severity questionnaires, modified Harris Hip Score (mHHS), Hip Outcome Score (HOS), international Hip Outcome Tool (iHOT-12) score, and radiological analysis. Descriptive statistics, analysis of covariance (ANCOVA), and Spearman partial correlation coefficients were used. Results. There was a significant difference in iHOT-12 scores between groups experiencing the most severe pain in the groin and the trochanter (p = 0.039). Additionally, more favourable mHHS scores were related to the presence of preoperative pain in trochanter (p = 0.049), lower back (p = 0.056), lateral thigh (p = 0.034), and posterior thigh (p = 0.005). Finally, the maximum severity of preoperative pain and number of pain locations had no significant relationship with PROMs (maximum severity: HHS: p = 0.928, HOS: p = 0.163, iHOT-12 p = 0.233; number of pain locations: HHS: p = 0.211; HOS: p = 0.801; iHOT-12: p = 0.112). Conclusion. Although there was a significant difference in iHOT-12 scores between patients with the most severe pain in the groin or trochanter, and the presence of pain in the trochanter, lower back, lateral thigh, or posterior thigh was related to higher mHHS scores, the majority of preoperative pain characteristics did not have a significant impact on outcomes. Therefore, a broad array of patients with hip OA might expect similar, favourable outcomes from THA notwithstanding preoperative pain characteristics. Cite this article: Bone Jt Open 2022;3(4):332–339

Aims. Total hip arthroplasty (THA) is a very successful and cost-effective operation, yet debate continues about the optimum fixation philosophy in different age groups. The concept of the 'cementless paradox' and the UK 'Getting it Right First Time' initiative encourage increased use of cemented fixation due to purported lower revision rates, especially in elderly patients, and decreased cost. Methods. In a high-volume, tertiary referral centre, we identified 10,112 THAs from a prospectively collected database, including 1,699 cemented THAs, 5,782 hybrid THAs, and 2,631 cementless THAs. The endpoint was revision for any reason. Secondary analysis included examination of implant survivorship in patients aged over 70 years, over 75 years, and over 80 years at primary THA. Results. Cemented fixation had the lowest implant survival in all age groups, with a total ten-year survivorship of 97.0% (95% confidence interval (CI) 95.8 to 97.8) in the cemented group, 97.6% (95% CI 96.9 to 98.1) in the hybrid group, and 97.9% (95% CI 96.9 to 98.6) in the cementless group. This was not statistically significant (p = 0.092). There was no age group where cemented fixation outperformed hybrid or cementless fixation. Conclusion. While all fixation techniques performed well at long-term follow-up, cemented fixation was associated with the lowest implant survival in all age groups, including in more elderly patients. We recommend that surgeons should carefully monitor their own outcomes and use fixation techniques that they are familiar with, and deliver the best outcomes in their own hands. Cite this article: Bone Joint J 2022;104-B(2):206–211

Aims. The aim of this study was to evaluate the healthcare costs and benefits of enoxaparin compared to aspirin in the prevention of symptomatic venous thromboembolism (VTE) after total hip arthroplasty (THA) or total knee arthroplasty (TKA) using data from the CRISTAL trial. Methods. This trial-based economic analysis reports value for money as incremental cost per quality-adjusted life-year (QALY) gained in 2022 Australian dollars, compared to a single threshold value of AUD$70,000 per QALY. Event costs were estimated based on occurrence of VTEs and bleeds, and on published guidelines for treatment. Unit costs were taken from Australian sources. QALYs were estimated using CRISTAL six-month follow-up data. Sensitivity analyses are presented that vary the cost of VTE treatment, and extend the analyses to two years. Results. The CRISTAL trial found that enoxaparin was more effective than aspirin in preventing symptomatic VTE within 90 days of THA or TKA (risk difference 1.97% (95% confidence interval (CI) 0.54% to 3.41%; p = 0.007)). The additional cost after a THA or TKA was AUD$83 (95% CI 68 to 97) for enoxaparin, and enoxaparin resulted in an additional 0.002 QALYs (95% CI -0.002 to 0.005). Incremental cost per QALY gained was AUD$50,567 (95% CI 15,513, dominated) for enoxaparin. We can be 60% confident that the incremental cost per QALY does not exceed the willingness-to-pay threshold of AUD$70,000. Increasing the cost of VTE treatment and extension of costs and consequences to two years suggested greater confidence that enoxaparin is good value for money (70% and 63% confidence, respectively). Conclusion. This analysis provides strong evidence that enoxaparin thromboprophylaxis following THA or TKA reduced VTEs, but weak evidence of net economic benefits over aspirin. If the value of avoiding VTEs is high, and there is a strong likelihood of VTE-related health impairments, we can be more confident that enoxaparin is cost-effective compared to aspirin. Cite this article: Bone Joint J 2024;106-B(6):589–595

Aims. This study reports the ten-year wear rates, incidence of osteolysis, clinical outcomes, and complications of a multicentre randomized controlled trial comparing oxidized zirconium (OxZr) versus cobalt-chrome (CoCr) femoral heads with ultra-high molecular weight polyethylene (UHMWPE) and highly cross-linked polyethylene (XLPE) liners in total hip arthroplasty (THA). Methods. Patients undergoing primary THA were recruited from four institutions and prospectively allocated to the following treatment groups: Group A, CoCr femoral head with XLPE liner; Group B, OxZr femoral head with XLPE liner; and Group C, OxZr femoral head with UHMWPE liner. All study patients and assessors recording outcomes were blinded to the treatment groups. The outcomes of 262 study patients were analyzed at ten years’ follow-up. Results. Patients in Group C were associated with increased mean liner wear rates compared to patients in Group A (0.133 mm/yr (SD 0.21) vs 0.031 mm/yr (SD 0.07), respectively; p < 0.001) and Group B (0.133 mm/yr (SD 0.21) vs 0.022 mm/yr (SD 0.05), respectively; p < 0.001) at ten years’ follow-up. Patients in Group C were also associated with increased risk of osteolysis and aseptic loosening requiring revision surgery, compared with patients in Group A (7/133 vs 0/133, respectively; p = 0.007) and Group B (7/133 vs 0/135, respectively; p = 0.007). There was a non-statistically significant trend towards increased mean liner wear rates in Group A compared with Group B (0.031 mm/yr (SD 0.07) vs 0.022 mm/yr (SD 0.05), respectively; p = 0.128). All three groups were statistically comparable preoperatively and at ten years’ follow-up when measuring normalized Western Ontario and McMaster Universities Osteoarthritis Index (p = 0.410), 36-Item Short Form Health Survey (p = 0.465 mental, p = 0.713 physical), and pain scale scores (p = 0.451). Conclusion. The use of UHMWPE was associated with progressively increased annual liner wear rates after THA compared to XLPE. At ten years’ follow-up, the group receiving UHMWPE demonstrated an increased incidence of osteolysis and aseptic loosening requiring revision surgery compared to XLPE. Femoral heads composed of OxZr were associated with trend towards reduced wear rates compared to CoCr, but this did not reach statistical significance and did not translate to any differences in osteolysis, functional outcomes, or revision surgery between the two femoral head components. Cite this article: Bone Joint J 2022;104-B(7):833–843

Aims. Total hip arthroplasty (THA) in patients with post-polio residual paralysis (PPRP) is challenging. Despite relief in pain after THA, pre-existing muscle imbalance and altered gait may cause persistence of difficulty in walking. The associated soft tissue contractures not only imbalances the pelvis, but also poses the risk of dislocation, accelerated polyethylene liner wear, and early loosening. Methods. In all, ten hips in ten patients with PPRP with fixed pelvic obliquity who underwent THA as per an algorithmic approach in two centres from January 2014 to March 2018 were followed-up for a minimum of two years (2 to 6). All patients required one or more additional soft tissue procedures in a pre-determined sequence to correct the pelvic obliquity. All were invited for the latest clinical and radiological assessment. Results. The mean Harris Hip Score at the latest follow-up was 79.2 (68 to 90). There was significant improvement in the coronal pelvic obliquity from 16.6. o. (SD 7.9. o. ) to 1.8. o. (SD 2.4. o. ; p < 0.001). Radiographs of all ten hips showed stable prostheses with no signs of loosening or migration, regardless of whether paralytic or non-paralytic hip was replaced. No complications, including dislocation or infection related to the surgery, were observed in any patient. The subtrochanteric shortening osteotomy done in two patients had united by nine months. Conclusion. Simultaneous correction of soft tissue contractures is necessary for obtaining a stable hip with balanced pelvis while treating hip arthritis by THA in patients with PPRP and fixed pelvic obliquity. Cite this article: Bone Jt Open 2021;2(9):696–704

Aims. Pelvic incidence (PI) is a position-independent spinopelvic parameter traditionally used by spinal surgeons to determine spinal alignment. Its relevance to the arthroplasty surgeon in assessing patient risk for total hip arthroplasty (THA) instability preoperatively is unclear. This study was undertaken to investigate the significance of PI relative to other spinopelvic parameter risk factors for instability to help guide its clinical application. Methods. Retrospective analysis was performed of a multicentre THA database of 9,414 patients with preoperative imaging (dynamic spinopelvic radiographs and pelvic CT scans). Several spinopelvic parameter measurements were made by engineers using advanced software including sacral slope (SS), standing anterior pelvic plane tilt (APPT), spinopelvic tilt (SPT), lumbar lordosis (LL), and PI. Lumbar flexion (LF) was determined by change in LL between standing and flexed-seated lateral radiographs. Abnormal pelvic mobility was defined as ∆SPT ≥ 20° between standing and flexed-forward positions. Sagittal spinal deformity (SSD) was defined as PI-LL mismatch > 10°. Results. PI showed a positive correlation with parameters of SS, SPT, and LL (r-value range 0.468 to 0.661). Patients with a higher PI value showed higher degrees of standing LL, likely as a compensatory measure to maintain sagittal spine balance. There was a positive correlation between LL and LF such that patients with less standing LL had decreased LF (r = 0.49). Similarly, there was a positive correlation between increased SSD and decreased LF (r = 0.54). PI in isolation did not show any significant correlation with lumbar (r = 0.04) or pelvic mobility (r = 0.02). The majority of patients (range 89.4% to 94.2%) had normal lumbar and pelvic mobility regardless of the PI value. Conclusion. The PI value alone is not indicative of either spinal or pelvic mobility, and thus in isolation may not be a risk factor for THA instability. Patients with SSD had higher rates of spinopelvic stiffness, which may be the mechanism by which PI relates to THA instability risk, but further clinical studies are required. Cite this article: Bone Joint J 2022;104-B(3):352–358

Aims. In computer simulations, the shape of the range of motion (ROM) of a stem with a cylindrical neck design will be a perfect cone. However, many modern stems have rectangular/oval-shaped necks. We hypothesized that the rectangular/oval stem neck will affect the shape of the ROM and the prosthetic impingement. Methods. Total hip arthroplasty (THA) motion while standing and sitting was simulated using a MATLAB model (one stem with a cylindrical neck and one stem with a rectangular neck). The primary predictor was the geometry of the neck (cylindrical vs rectangular) and the main outcome was the shape of ROM based on the prosthetic impingement between the neck and the liner. The secondary outcome was the difference in the ROM provided by each neck geometry and the effect of the pelvic tilt on this ROM. Multiple regression was used to analyze the data. Results. The stem with a rectangular neck has increased internal and external rotation with a quatrefoil cross-section compared to a cone in a cylindrical neck. Modification of the cup orientation and pelvic tilt affected the direction of projection of the cone or quatrefoil shape. The mean increase in internal rotation with a rectangular neck was 3.4° (0° to 7.9°; p < 0.001); for external rotation, it was 2.8° (0.5° to 7.8°; p < 0.001). Conclusion. Our study shows the importance of attention to femoral implant design for the assessment of prosthetic impingement. Any universal mathematical model or computer simulation that ignores each stem’s unique neck geometry will provide inaccurate predictions of prosthetic impingement. Cite this article: Bone Joint Res 2021;10(12):780–789

Aims. This study aimed to use intraoperative free electromyography to examine how the placement of a retractor at different positions along the anterior acetabular wall may affect the femoral nerve during total hip arthroplasty (THA) when undertaken using the direct anterior approach (THA-DAA). Methods. Intraoperative free electromyography was performed during primary THA-DAA in 82 patients (94 hips). The highest position of the anterior acetabular wall was defined as the “12 o’clock” position (middle position) when the patient was in supine position. After exposure of the acetabulum, a retractor was sequentially placed at the ten, 11, 12, one, and two o’clock positions (right hip; from superior to inferior positions). Action potentials in the femoral nerve were monitored with each placement, and the incidence of positive reactions (defined as explosive, frequent, or continuous action potentials, indicating that the nerve was being compressed) were recorded as the primary outcome. Secondary outcomes included the incidence of positive reactions caused by removing the femoral head, and by placing a retractor during femoral exposure; and the incidence of femoral nerve palsy, as detected using manual testing of the strength of the quadriceps muscle. Results. Positive reactions were significantly less frequent when the retractor was placed at the ten (15/94; 16.0%), 11 (12/94; 12.8%), or 12 o’clock positions (19/94; 20.2%), than at the one (37/94; 39.4%) or two o’clock positions (39/94; 41.5%) (p < 0.050). Positive reactions also occurred when the femoral head was removed (28/94; 29.8%), and when a retractor was placed around the proximal femur (34/94; 36.2%) or medial femur (27/94; 28.7%) during femoral exposure. After surgery, no patient had reduced strength in the quadriceps muscle. Conclusion. Placing the anterior acetabular retractor at the one or two o’clock positions (right hip; inferior positions) during THA-DAA can increase the rate of electromyographic signal changes in the femoral nerve. Thus, placing a retractor in these positions may increased the risk of the development of a femoral nerve palsy. Cite this article: Bone Joint J 2022;104-B(2):193–199

Aims. Total hip arthroplasty (THA) patients undergoing or having a prior lumbar spine fusion (LSF) have an increased risk of mechanical complications. The aim of this registry-based, retrospective comparative cohort study is to assess the longer term survival of THA in patients who have undergone a LSF during a 17-year period (2000 to 2017). Methods. A registry-based population study was conducted on 679 patients who underwent both THA and LSF surgeries. Patients were identified from the regional arthroplasty data base and cross linked to patients with LSF from the regional hospital discharge database between 2000 and 2017. Demographic data, diagnosis leading to primary THA, primary implant survival, perioperative complications, number and causes of failure, and patients requiring revision arthroplasty were collated and compared. For comparison, data from 67,919 primary THAs performed during the same time time period were also retrieved and analyzed. Results. Patients undergoing THA and LSF showed homogeneous demographic data compared to those undergoing THA alone, but a significantly lower eight-year THA implant survival (96.7 vs 96.0, p = 0.024) was observed. Moreover, THA plus LSF patients showed increased incidence of mechanical complications in the first two years after THA surgery compared to THA alone patients. Conclusion. This registry-based population study shows that approximately 679 (1%) THA patients were subjected to LSF. Patients undergoing THA and LSF have an increased risk of mechanical complications with their THA and a slightly increased risk of revision arthroplasty. Cite this article: Bone Joint J 2021;103-B(3):486–491

Aims. Use of the direct anterior approach (DAA) for total hip arthroplasty (THA) has increased in recent years due to proposed benefits, including a lower risk of dislocation and improved early functional recovery. This study investigates the dislocation rate in a non-selective, consecutive cohort undergoing THA via the DAA without any exclusion or bias in patient selection based on habitus, deformity, age, sex, or fixation method. Methods. We retrospectively reviewed all patients undergoing THA via the DAA between 2011 and 2017 at our institution. Primary outcome was dislocation at minimum two-year follow-up. Patients were stratified by demographic details and risk factors for dislocation, and an in-depth analysis of dislocations was performed. Results. A total of 2,831 hips in 2,205 patients were included. Mean age was 64.9 years (24 to 96), mean BMI was 29.2 kg/m. 2. (15.1 to 53.8), and 1,595 patients (56.3%) were female. There were 11 dislocations within one year (0.38%) and 13 total dislocations at terminal follow-up (0.46%). Five dislocations required revision. The dislocation rate for surgeons who had completed their learning curve was 0.15% compared to 1.14% in those who had not. The cumulative periprosthetic infection and fracture rates were 0.53% and 0.67%, respectively. Conclusion. In a non-selective, consecutive cohort of patients undergoing THA via the DAA, the risk of dislocation is low, even among patients with risk factors for instability. Our data further suggest that the DAA can be safely used in all hip arthroplasty patients without an increased risk of wound complications, fracture, infection, or revision. The inclusion of seven surgeons increases the generalizability of these results. Cite this article: Bone Joint J 2021;103-B(7 Supple B):38–45

Aims. The value of core decompression (CD) in the treatment of osteonecrosis of the femoral head (ONFH) remains controversial. We conducted a systematic review and meta-analysis to evaluate whether CD combined with other treatments could improve the clinical and radiological outcomes of ONFH patients compared with CD alone. Methods. We searched the PubMed, Embase, Web of Science, and Cochrane Library databases until June 2020. All randomized controlled trials (RCTs) and clinical controlled trials (CCTs) comparing CD alone and CD combined with other measures (CD + cell therapy, CD + bone grafting, CD + porous tantalum rod, etc.) for the treatment of ONFH were considered eligible for inclusion. The primary outcomes of interest were Harris Hip Score (HHS), ONFH stage progression, structural failure (collapse) of the femoral head, and conversion to total hip arthroplasty (THA). The pooled data were analyzed using Review Manager 5.3 software. Results. A total of 20 studies with 2,123 hips were included (CD alone = 768, CD combined with other treatments = 1,355). The combination of CD with other therapeutic interventions resulted in a higher HHS (mean difference (MD) = 6.46, 95% confidence interval (CI) = 2.10 to 10.83, p = 0.004) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score (MD = −10.92, 95% CI = -21.41 to -4.03, p = 0.040) and a lower visual analogue scale (VAS) score (MD = −0.99, 95% CI = -1.56 to -0.42, p < 0.001) than CD alone. For the rates of disease stage progression, 91 (20%) progressed in the intervention group compared to 146 (36%) in the control group (odds ratio (OR) = 0.32, 95% CI = 0.16 to 0.64, p = 0.001). In addition, the intervention group had a more significant advantage in delaying femoral head progression to the collapsed stage (OR = 0.32, 95% CI = 0.17 to 0.61, p < 0.001) and reducing the odds of conversion to THA (OR = 0.35, 95% CI = 0.23 to 0.55, p < 0.001) compared to the control group. There were no serious adverse events in either group. Subgroup analysis showed that the addition of cell therapy significantly improved clinical and radiological outcomes compared to CD alone, and this approach appeared to be more effective than other therapies, particularly in precollapse (stage I to II) ONFH patients. Conclusion. There was marked heterogeneity in the studies. There is a trend towards improved clinical outcomes with the addition of stem cell therapy to CD. Cite this article: Bone Joint Res 2021;10(7):445–458

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

Aims. Total hip arthroplasty (THA) using the direct anterior approach (DAA) is undertaken with the patient in the supine position, creating an opportunity to replace both hips under one anaesthetic. Few studies have reported simultaneous bilateral DAA-THA. The aim of this study was to characterize a cohort of patients selected for this technique by a single, high-volume arthroplasty surgeon and to investigate their early postoperative clinical outcomes. Methods. Using an institutional database, we reviewed 643 patients who underwent bilateral DAA-THA by a single surgeon between 1 January 2010 and 31 December 2018. The demographic characteristics of the 256 patients (39.8%) who underwent simultaneous bilateral DAA-THA were compared with the 387 patients (60.2%) who underwent staged THA during the same period of time. We then reviewed the length of stay, rate of discharge home, 90-day complications, and readmissions for the simultaneous bilateral group. Results. Patients undergoing simultaneous bilateral DAA-THA had a 3.5% transfusion rate, a 1.8 day mean length of stay, a 98.1% rate of discharge home, and low rates of 90-day infection (0.39%), dislocation (0.39%), periprosthetic fracture (0.77%), venous thromboembolism (0%), haematoma (0.39%), further surgery (0.77%), and readmission (0.77%). These patients were significantly younger (mean 58.2 years vs 62.5 years; p < 0.001), more likely to be male (60.3% vs 46.5%; p < 0.001), and with a trend towards having a lower mean BMI (27.8 kg/m. 2. vs 28.4 kg/m. 2. ; p = 0.071) than patients who underwent staged bilateral DAA-THA. Conclusion. Patients selected for simultaneous bilateral DAA-THA in a single surgeon’s practice had a 3% rate of postoperative transfusion and a low rate of complications, readmissions, and discharge to a rehabilitation facility. Simultaneous bilateral DAA-THA appears to be a reasonable and safe form of treatment for patients with bilateral symptomatic osteoarthritis of the hip when undertaken by an experienced arthroplasty surgeon with appropriate selection criteria. Cite this article: Bone Joint J 2021;103-B(7 Supple B):116–121

Aims. Monocyte-lymphocyte ratio (MLR) or neutrophil-lymphocyte ratio (NLR) are useful for diagnosing periprosthetic joint infection (PJI), but their diagnostic values are unclear for screening fixation-related infection (FRI) in patients for whom conversion total hip arthroplasty (THA) is planned after failed internal fixation for femoral neck fracture. Methods. We retrospectively included 340 patients who underwent conversion THA after internal fixation for femoral neck fracture from January 2008 to September 2020. Those patients constituted two groups: noninfected patients and patients diagnosed with FRI according to the 2013 International Consensus Meeting Criteria. Receiver operating characteristic (ROC) curves were used to determine maximum sensitivity and specificity of these two preoperative ratios. The diagnostic performance of the two ratios combined with preoperative CRP or ESR was also evaluated. Results. The numbers of patients with and without FRI were 19 (5.6%) and 321 (94.4%), respectively. Areas under the ROC curve for diagnosing FRI were 0.763 for MLR, 0.686 for NLR, 0.905 for CRP, and 0.769 for ESR. Based on the Youden index, the optimal predictive cutoffs were 0.25 for MLR and 2.38 for NLR. Sensitivity and specificity were 78.9% and 71.0% for MLR, and 78.9% and 56.4% for NLR, respectively. The combination of CRP with MLR showed a sensitivity of 84.2% and specificity of 94.6%, while the corresponding values for the combination of CRP with NLR were 89.5% and 91.5%, respectively. Conclusion. The presence of preoperative FRI among patients undergoing conversion THA after internal fixation for femoral neck fracture should be determined. The combination of preoperative CRP with NLR is sensitive tool for screening FRI in those patients. Cite this article: Bone Joint J 2021;103-B(9):1534–1540

Aims. A typical pattern of blood loss associated with total hip arthroplasty (THA) is 200 ml intraoperatively and 1.3 l in the first 48 postoperative hours. Tranexamic acid (TXA) is most commonly given as a single preoperative dose only and is often withheld from patients with a history of thromboembolic disease as they are perceived to be “high-risk” with respect to postoperative venous thromboembolism (VTE). The TRanexamic ACid for 24 hours trial (TRAC-24) aimed to identify if an additional 24-hour postoperative TXA regime could further reduce blood loss beyond a once-only dose at the time of surgery, without excluding these high-risk patients. Methods. TRAC-24 was a prospective, phase IV, single centre, open label, parallel group, randomized controlled trial (RCT) involving patients undergoing primary unilateral elective THA. The primary outcome measure was the indirect calculated blood loss (IBL) at 48 hours. The patients were randomized into three groups. Group 1 received 1 g intravenous (IV) TXA at the time of surgery and an additional oral regime for 24 hours postoperatively, group 2 only received the intraoperative dose, and group 3 did not receive any TXA. Results. A total of 534 patients were randomized, with 233 in group 1, 235 in group 2, and 66 in group 3; 92 patients (17.2%) were considered high-risk. The mean IBL did not differ significantly between the two intervention groups (848.4 ml (SD 463.8) for group 1, and 843.7 ml (SD 478.7) for group 2; mean difference -4.7 ml (95% confidence interval -82.9 to 92.3); p = 0.916). No differences in mortality or incidence of VTE were observed between any group. Conclusion. The addition of oral TXA for 24 hours postoperatively does not reduce blood loss beyond that achieved with a single 1 g IV perioperative dose alone. There may be a clinically relevant difference in patients with a normal BMI, which warrants further investigation. Critically, there were no safety issues in patients with a history of thromboembolic, cardiovascular, or cerebrovascular disease. Cite this article: Bone Joint J 2021;103-B(7):1197–1205

Aims. We present the development of a day-case total hip arthroplasty (THA) pathway in a UK National Health Service institution in conjunction with an extensive evidence-based summary of the interventions used to achieve successful day-case THA to which the protocol is founded upon. Methods. We performed a prospective audit of day-case THA in our institution as we reinitiate our full capacity elective services. In parallel, we performed a review of the literature reporting complication or readmission rates at ≥ 30-day postoperative following day-case THA. Electronic searches were performed using four databases from the date of inception to November 2020. Relevant studies were identified, data extracted, and qualitative synthesis performed. Results. Our evaluation and critique of the evidence-based literature identifies day-case THA to be safe, effective, and economical, benefiting both patients and healthcare systems alike. We further validate this with our institutional elective day surgery arthroplasty pathway (EDSAP) and report a small cohort of successful day-case THA cases as an example in the early stages of this practice in our unit. Conclusion. Careful patient selection and education, adequate perioperative considerations, including multimodal analgesia, surgical technique and blood loss management protocols and appropriate postoperative pathways comprising reliable discharge criteria are essential for successful day-case THA. Cite this article: Bone Jt Open 2021;2(2):93–102

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