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

Osteoporosis can determine surgical strategy for total hip arthroplasty (THA), and perioperative fracture risk. The aims of this study were to use hip CT to measure femoral bone mineral density (BMD) using CT X-ray absorptiometry (CTXA), determine if systematic evaluation of preoperative femoral BMD with CTXA would improve identification of osteopenia and osteoporosis compared with available preoperative dual-energy X-ray absorptiometry (DXA) analysis, and determine if improved recognition of low BMD would affect the use of cemented stem fixation.

Aims. The primary objective of this study was to develop a validated classification system for assessing iatrogenic bone trauma and soft-tissue injury during total hip arthroplasty (THA). The secondary objective was to compare macroscopic bone trauma and soft-tissues injury in conventional THA (CO THA) versus robotic arm-assisted THA (RO THA) using this classification system. Methods. This study included 30 CO THAs versus 30 RO THAs performed by a single surgeon. Intraoperative photographs of the osseous acetabulum and periacetabular soft-tissues were obtained prior to implantation of the acetabular component, which were used to develop the proposed classification system. Interobserver and intraobserver variabilities of the proposed classification system were assessed. Results. The BOne trauma and Soft-Tissue Injury classification system in total Hip arthroplasty (BOSTI Hip) grades osseous acetabular trauma and periarticular muscle damage during THA. The classification system has an interclass correlation coefficient of 0.90 (95% CI 0.86 to 0.93) for interobserver agreement and 0.89 (95% CI 0.84 to 0.93) for intraobserver agreement. RO THA was associated with improved BOSTI Hip scores (p = 0.002) and more pristine osseous surfaces in the anterior superior (p = 0.001) and posterior superior (p < 0.001) acetabular quadrants compared with CO THA. There were no differences between the groups in relation to injury to the gluteus medius (p = 0.084), obturator internus (p = 0.241), piriformis (p = 0.081), superior gamellus (p = 0.116), inferior gamellus (p = 0.132), quadratus femoris (p = 0.208), and vastus lateralis (p = 0.135), but overall combined muscle injury was reduced in RO THA compared with CO THA (p = 0.023). Discussion. The proposed BOSTI Hip classification provides a reproducible grading system for stratifying iatrogenic bone trauma and soft-tissue injury during THA. RO THA was associated with improved BOSTI Hip scores, more pristine osseous acetabular surfaces, and reduced combined periarticular muscle injury compared with CO THA. Further research is required to understand if these intraoperative findings translate to differences in clinical outcomes between the treatment groups. Cite this article: Bone Joint J 2024;106-B(9):898–906

Aims. The aim of this study was to determine if the Oxford Knee and Hip Score (OKHS) can accurately predict when a primary knee or hip referral is deemed nonsurgical versus surgical by the surgeon during their first consultation, and to identify nonsurgical OKHS screening thresholds. Patients and Methods. We retrospectively reviewed pre-consultation OKHS for all consecutive primary total knee arthroplasty (TKA) and total hip arthroplasty (THA) consultations of a single surgeon over three years. The 1436 knees (1016 patients) and 478 hips (388 patients) included were categorized based on the surgeon’s decision into those offered surgery during the first consultation versus those not (nonsurgical). Spearman’s rank correlation coefficients and receiver operating characteristic (ROC) curve analysis were performed. Results. Oxford Scores were better for the nonsurgical cohorts (p < 0.001) and correlated with the surgical decision (p < 0.001). ROC area under the curve values for knees (0.83, 95% confidence intervals (CI) 0.81 to 0.85) and hips (0.87, 95% CI 0.84 to 0.91) were excellent. A conservative and effective threshold for knees is Oxford Knee Score (OKS) > 32 points (sensitivity = 0.997, negative predictive value (NPV) = 0.992) and for hips is Oxford Hip Score (OHS) > 34 points (sensitivity = 0.997, NPV = 0.978). Severable potential lower OKHS thresholds were identified. Conclusion. Pre-consultation OKHS demonstrate good ability to predict when a primary TKA or THA referral will be deemed nonsurgical in a single surgeon’s practice. Multiple OKHS thresholds can effectively screen out nonsurgical referrals. Cite this article: Bone Joint J 2019;101-B(6 Supple B):23–30

Aims. The direct anterior approach (DAA) for total hip arthroplasty (THA) has potential advantages over other approaches and is most commonly performed with the patient in the supine position. We describe a technique for DAA THA with the patient in the lateral decubitus position and report the early clinical and radiological outcomes, the characteristics of the learning curve, and perioperative complications. Methods. All primary DAA THAs performed in the lateral position by a single surgeon over a four-year period from the surgeon’s first case using the technique were identified from a prospectively collected database. Modified Harris Hip Scores (mHHS) were collected to assess clinical outcome, and routine radiological analysis was performed. Retrospective review of the medical records identified perioperative complications, the characteristics of the learning curve, and revisions. Results. A total of 257 patients were included in the study. Their mean age was 60 years (SD 9.0). A total of 164 (64%) were female. The mean mHHS improved significantly from 52.1 (SD 16.2) preoperatively to 94.4 (SD 11) at a follow-up of one year (p < 0.001), with 212 of 225 patients (94%) achieving a minimal clinically important difference (MCID) (> 8 points). Radiological evaluation showed a mean leg length discrepancy of 2.6 mm (SD 5.9) and a mean difference in femoral offset of 0.2 mm (SD 4.9). A total of 234/243 acetabular components (96.3%) were positioned within Lewinnek’s safe zone. Analysis of operating time, blood loss, the position of the components, and complications did not identify a learning curve. A total of 14 patients (5.4%) had a major perioperative complication and three (1.2%) required revision THA. There were no major neurovascular complications and no dislocations. Conclusion. We have described and analyzed a surgical technique for undertaking DAA THA in the familiar lateral decubitus position using a routine operating table, positioning devices, and instrumentation, and shown that it can be performed safely and effectively under these circumstances. Cite this article: Bone Joint J 2021;103-B(7 Supple B):53–58

Aims. Surgical costs are a major component of healthcare expenditures in the USA. Intraoperative communication is a key factor contributing to patient outcomes. However, the effectiveness of communication is only partially determined by the surgeon, and understanding how non-surgeon personnel affect intraoperative communication is critical for the development of safe and cost-effective staffing guidelines. Operative efficiency is also dependent on high-functioning teams and can offer a proxy for effective communication in highly standardized procedures like primary total hip and knee arthroplasty. We aimed to evaluate how the composition and dynamics of surgical teams impact operative efficiency during arthroplasty. Methods. We performed a retrospective review of staff characteristics and operating times for 112 surgeries (70 primary total hip arthroplasties (THAs) and 42 primary total knee arthroplasties (TKAs)) conducted by a single surgeon over a one-year period. Each surgery was evaluated in terms of operative duration, presence of surgeon-preferred staff, and turnover of trainees, nurses, and other non-surgical personnel, controlling cases for body mass index, presence of osteoarthritis, and American Society of Anesthesiologists (ASA) score. Results. Turnover among specific types of operating room staff, including the anaesthesiologist (p = 0.011), circulating nurse (p = 0.027), and scrub nurse (p = 0.006), was significantly associated with increased operative duration. Furthermore, the presence of medical students and nursing students were associated with improved intraoperative efficiency in TKA (p = 0.048) and THA (p = 0.015), respectively. The presence of surgical fellows (p > 0.05), vendor representatives (p > 0.05), and physician assistants (p > 0.05) had no effect on intraoperative efficiency. Finally, the presence of the surgeon’s 'preferred' staff did not significantly shorten operative duration, except in the case of residents (p = 0.043). Conclusion. Our findings suggest that active management of surgical team turnover and composition may provide a means of improving intraoperative efficiency during THA and TKA. Cite this article: Bone Joint J 2021;103-B(2):347–352

Aims. The Birmingham Hip Resurfacing (BHR) was introduced in 1997 to address the needs of young active patients using a historically proven large-diameter metal-on-metal (MoM) bearing. A single designer surgeon’s consecutive series of 130 patients (144 hips) was previously reported at five and ten years, reporting three and ten failures, respectively. The aim of this study was to extend the follow-up of this original cohort at 25 years. Methods. The study extends the reporting on the first consecutive 144 resurfacing procedures in 130 patients for all indications. All operations were undertaken between August 1997 and May 1998. The mean age at operation was 52.1 years (SD 9.93; 17 to 76), and included 37 female patients (28.5%). Failure was defined as revision of either component for any reason. Kaplan-Meier survival analysis was performed. Routine follow-up with serum metal ion levels, radiographs, and Oxford Hip Scores (OHSs) was undertaken. Results. Overall implant survival was 83.50% (95% confidence interval (CI) 0.79 to 0.90) at 25 years, and the number at risk was 79. Survival in male patients at 25 years was 89.5% (95% CI 0.83 to 0.96) compared to 66.9% for female patients (95% CI 0.51 to 0.83). Ten additional failures occurred in the period of ten to 25 years. These involved an adverse reaction to metal debris in four patients, a periprosthetic femoral neck fracture affecting five patients, and aseptic loosening in one patient. The median chromium levels were 49.50 nmol/l (interquartile range (IQR) 34 to 70), and the median cobalt serum levels were 42 nmol/l (IQR 24.50 to 71.25). The median OHS at last follow-up was 35 (IQR 10 to 48). During the 25-year study period, 29 patients died. Patient survival at 25 years was 75.10% (95% CI 0.67 to 0.83). Conclusion. This study demonstrates that MoM hip resurfacing using the BHR provides a durable alternative to total hip arthroplasty (THA), particularly in younger male patients with osteoarthritis wishing to maintain a high level of function. These results compare favourably to the best results for THAs. Cite this article: Bone Joint J 2024;106-B(6):540–547

Aims. The purpose of this study was to compare the clinical, radiological, and patient-reported outcome measures (PROMs) in the first 100 consecutive patients undergoing total hip arthroplasty (THA) via a direct superior approach (DSA) with a matched group of patients undergoing THA by the same surgeon, using a posterolateral approach (PLA). Methods. This was a retrospective single surgeon study comparing the first 100 consecutive DSA THA patients with a matched group of patients using a standard PLA. Case notes were examined for patient demographics, length of hospital stay, operating time, intra- and postoperative complications, pain score, satisfaction score, and Oxford Hip Score (OHS). Leg length discrepancy and component positioning were measured from postoperative plain radiographs. Results. The DSA patients had a shorter length of hospital stay (mean 2.09 days (SD 1.20) DSA vs 2.74 days (SD 1.17) PLA; p < 0.001) and shorter time to discharge from the inpatient physiotherapy teams (mean 1.44 days (SD 1.17) DSA vs 1.93 days (SD 0.96) PLA; p < 0.001). There were no differences in operating time (p = 0.505), pain levels up to postoperative day 1 (p = 0.106 to p =0.242), OHS (p = 0.594 to p = 0.815), satisfaction levels (p = 0.066 to p = 0.299), stem alignment (p = 0.240), acetabular component inclination (p < 0.001) and anteversion (p < 0.001), or leg length discrepancy (p = 0.134). Conclusion. While the DSA appears safe and was not associated with a significant difference in PROMs, radiological findings, or intraoperative or postoperative complications, a randomized controlled trial with functional outcomes in the postoperative phase is needed to evaluate this surgical approach formally. Cite this article: Bone Joint J 2021;103-B(3):500–506

Aims. The aim of this study was to report the implant survival and patient-reported outcome measures (PROMs) in a consecutive series of patients aged less than 50 years at the time of arthroplasty using the Birmingham Hip Resurfacing system (BHR), with a minimum follow-up of ten years. Patients and Methods. A total of 226 patients with osteoarthritis of the hip, who underwent BHR and presented to a single surgeon, were included in the study. Survival of the implant was confirmed by cross-checking with the Australian Orthopaedic Association National Joint Replacement Registry. Kaplan–Meier survival curves with 95% confidence intervals (CIs) were constructed. Pre- and postoperative PROMs were compared with t-tests, and postoperative scores were compared using anchor analysis with age and gender matched normative data. Results. At median follow-up of 12 years (interquartile range (IQR) 10 to 13), six BHRs were revised, with a cumulative rate of survival of 96.8% (95% confidence interval (CI) 94.2 to 99.4) at 15 years, and with a significantly lower (p = 0.019) cumulative rate of revision than the national average for the same device at ten years. Most revisions (n = 4) were undertaken early, less than three years postoperatively, and occurred in women. Patient-reported general health (Veteran’s Rand-36), disease state (Western Ontario and McMaster Universities Osteoarthritis Index), function (modified Harris Hip Score) and level of activity (Tegner activity score) maintained significant (p < 0.01 for each) improvements beyond ten years postoperatively and were equal to, or exceeded, age- and gender-matched normative data in more than 80% of the patients. Conclusion. Longer term PROMs after BHR, from a single surgeon, for patients aged less than 50 years remain under-reported. We found that the outcome after a BHR, at a minimum of ten years postoperatively, remained satisfactory, particularly for self-reported hip function

Aims. Spinal deformity surgery carries the risk of neurological injury. Neurophysiological monitoring allows early identification of intraoperative cord injury which enables early intervention resulting in a better prognosis. Although multimodal monitoring is the ideal, resource constraints make surgeon-directed intraoperative transcranial motor evoked potential (TcMEP) monitoring a useful compromise. Our experience using surgeon-directed TcMEP is presented in terms of viability, safety, and efficacy. Methods. We carried out a retrospective review of a single surgeon’s prospectively maintained database of cases in which TcMEP monitoring had been used between 2010 and 2017. The upper limbs were used as the control. A true alert was recorded when there was a 50% or more loss of amplitude from the lower limbs with maintained upper limb signals. Patients with true alerts were identified and their case history analyzed. Results. Of the 299 cases reviewed, 279 (93.3%) had acceptable traces throughout and awoke with normal clinical neurological function. No patient with normal traces had a postoperative clinical neurological deficit. True alerts occurred in 20 cases (6.7%). The diagnoses of the alert group included nine cases of adolescent idiopathic scoliosis (AIS) (45%) and six of congenital scoliosis (30%). The incidence of deterioration based on diagnosis was 9/153 (6%) for AIS, 6/30 (20%) for congenital scoliosis, and 2/16 (12.5%) for spinal tuberculosis. Deterioration was much more common in congenital scoliosis than in AIS (p = 0.020). Overall, 65% of alerts occurred during rod instrumentation: 15% occurred during decompression of the internal apex in vertebral column resection surgery. Four alert cases (20%) awoke with clinically detectable neurological compromise. Conclusion. Surgeon-directed TcMEP monitoring has a 100% negative predictive value and allows early identification of physiological cord distress, thereby enabling immediate intervention. In resource constrained environments, surgeon-directed TcMEP is a viable and effective method of intraoperative spinal cord monitoring. Level of evidence: III. Cite this article: Bone Joint J 2021;103-B(3):547–552

Aims. The aim of this study was to investigate the efficacy of coccygectomy in patients with persistent coccydynia and coccygeal instability. Methods. The Danish National Spine Registry, DaneSpine, was used to identify 134 consecutive patients who underwent surgery, performed by a single surgeon between 2011 and 2019. Routine demographic data, surgical variables, and patient-reported outcomes, including a visual analogue scale (VAS) (0 to 100) for pain, Oswestry Disability Index (ODI), EuroQol five-dimension questionnaire (EQ-5D), and the Physical Component Score (PCS) and Mental Component Score (MCS) of the 36-Item Short-Form Health Survey questionnaire (SF-36) were collected at baseline and one-year postoperatively. Results. A total of 112 (84%) patients with a minimum follow-up of one year had data available for analysis. Their mean age was 41.9 years, and 15 (13%) were males. At 12 months postoperatively, there were statistically significant improvements (p < 0.001) from baseline for the mean VAS for pain (70.99 to 35.34), EQ-5D (0.52 to 0.75), ODI (31.84 to 18.00), and SF-36 PCS (38.17 to 44.74). A total of 78 patients (70%) were satisfied with the outcome of treatment. Conclusion. Patients with persistent coccydynia and coccygeal instability resistant to nonoperative treatment may benefit from coccygectomy. Cite this article: Bone Joint J 2021;103-B(3):542–546

Aims. Improvements in functional results and long-term survival are variable following conversion of hip fusion to total hip arthroplasty (THA) and complications are high. The aim of the study was to analyze the clinical and functional results in patients who underwent conversion of hip fusion to THA using a consistent technique and uncemented implants. Methods. A total of 39 hip fusion conversions to THA were undertaken in 38 patients by a single surgeon employing a consistent surgical technique and uncemented implants. Parameters assessed included Harris Hip Score (HHS) for function, range of motion (ROM), leg length discrepancy (LLD), satisfaction, and use of walking aid. Radiographs were reviewed for loosening, subsidence, and heterotopic ossification (HO). Postoperative complications and implant survival were assessed. Results. At mean 12.2 years (2 to 24) follow-up, HHS improved from mean 34.2 (20.8 to 60.5) to 75 (53.6 to 94.0; p < 0.001). Mean postoperative ROM was flexion 77° (50° to 95°), abduction 30° (10° to 40°), adduction 20° (5° to 25°), internal rotation 18° (2° to 30°), and external rotation 17° (5° to 30°). LLD improved from mean -3.36 cm (0 to 8) to postoperative mean -1.14 cm (0 to 4; p < 0.001). Postoperatively, 26 patients (68.4%) required the use of a walking aid. Complications included one (2.5%) dislocation, two (5.1%) partial sciatic nerve injuries, one (2.5%) deep periprosthetic joint infection, two instances of (5.1%) acetabular component aseptic loosening, two (5.1%) periprosthetic fractures, and ten instances of HO (40%), of which three (7.7%) were functionally limiting and required excision. Kaplan-Meier Survival was 97.1% (95% confidence interval (CI) 91.4% to 100%) at ten years and 88.2% (95% CI 70.96 to 100) at 15 years with implant revision for aseptic loosening as endpoint and 81.7% (95% CI 70.9% to 98.0%) at ten years and 74.2% (95% CI 55.6 to 92.8) at 15 years follow-up with implant revision for all cause failure as endpoint. Conclusion. The use of an optimal and consistent surgical technique and cementless implants can result in significant functional improvement, low complication rates, long-term implant survival, and high patient satisfaction following conversion of hip fusion to THA. The possibility of requiring a walking aid should be discussed with the patient before surgery. Cite this article: Bone Joint J 2021;103-B(7 Supple B):129–134

Aims. Despite advances in the treatment of paediatric hip disease, adolescent and young adult patients can develop early onset end-stage osteoarthritis. The aims of this study were to address the indications and medium-term outcomes for total hip arthroplasty (THA) with ceramic bearings for teenage patients. Methods. Surgery was performed by a single surgeon working in the paediatric orthopaedic unit of a tertiary referral hospital. Databases were interrogated from 2003 to 2017 for all teenage patients undergoing THA with a minimum 2.3 year follow-up. Data capture included patient demographics, the underlying hip pathology, number of previous surgeries, and THA prostheses used. Institutional ethical approval was granted to contact patients for prospective clinical outcomes and obtain up-to-date radiographs. In total, 60 primary hips were implanted in 51 patients (35 female, 16 male) with nine bilateral cases. The mean age was 16.7 years (12 to 19) and mean follow-up was 9.3 years (2.3 to 16.8). Results. The most common indication for teenage hip arthroplasty was avascular necrosis secondary to slipped upper femoral epiphysis (31%; n = 16). Overall, 64% of patients (n = 33) had undergone multiple previous operations. The survival at follow-up was 97%; two patients required revision for aseptic loosening (one femoral stem, one acetabular component). Both patients had fused hips noted at the time of arthroplasty. A further two patients had radiolucent lines but were asymptomatic. At latest follow-up the mean Oxford Hip Score was 44 (31 to 48) and a Visual Analogue Scale measurement of 1.5, indicating satisfactory function. Conclusion. Operating on this cohort can be complicated by multiple previous surgeries and distorted anatomy, which in some cases require custom-made prostheses. We have demonstrated a good outcome with low revision rate in this complex group of patients. Cite this article: Bone Joint J 2020;102-B(11):1491–1496

Aims. Robotic-assisted total knee arthroplasty (RA-TKA) is theoretically more accurate for component positioning than TKA performed with mechanical instruments (M-TKA). Furthermore, the ability to incorporate soft-tissue laxity data into the plan prior to bone resection should reduce variability between the planned polyethylene thickness and the final implanted polyethylene. The purpose of this study was to compare accuracy to plan for component positioning and precision, as demonstrated by deviation from plan for polyethylene insert thickness in measured-resection RA-TKA versus M-TKA. Methods. A total of 220 consecutive primary TKAs between May 2016 and November 2018, performed by a single surgeon, were reviewed. Planned coronal plane component alignment and overall limb alignment were all 0° to the mechanical axis; tibial posterior slope was 2°; and polyethylene thickness was 9 mm. For RA-TKA, individual component position was adjusted to assist gap-balancing but planned coronal plane alignment for the femoral and tibial components and overall limb alignment remained 0 ± 3°; planned tibial posterior slope was 1.5°. Mean deviations from plan for each parameter were compared between groups for positioning and size and outliers were assessed. Results. In all, 103 M-TKAs and 96 RA-TKAs were included. In RA-TKA versus M-TKA, respectively: mean femoral positioning (0.9° (SD 1.2°) vs 1.7° (SD 1.1°)), mean tibial positioning (0.3° (SD 0.9°) vs 1.3° (SD 1.0°)), mean posterior tibial slope (-0.3° (SD 1.3°) vs 1.7° (SD 1.1°)), and mean mechanical axis limb alignment (1.0° (SD 1.7°) vs 2.7° (SD 1.9°)) all deviated significantly less from the plan (all p < 0.001); significantly fewer knees required a distal femoral recut (10 (10%) vs 22 (22%), p = 0.033); and deviation from planned polyethylene thickness was significantly less (1.4 mm (SD 1.6) vs 2.7 mm (SD 2.2), p < 0.001). Conclusion. RA-TKA is significantly more accurate and precise in planning both component positioning and final polyethylene insert thickness. Future studies should investigate whether this increased accuracy and precision has an impact on clinical outcomes. The greater accuracy and reproducibility of RA-TKA may be important as precise new goals for component positioning are developed and can be further individualized to the patient. Cite this article: Bone Joint J 2021;103-B(6 Supple A):74–80

Aims. Tranexamic acid (TXA) has been shown to reduce blood loss and transfusion requirements in patients undergoing orthopaedic surgery. There remains a lack of prospective evidence for the use of TXA in patients undergoing periacetabular osteotomy (PAO). The purpose of this study was to determine if intravenous (IV) TXA is effective in reducing calculated blood loss and transfusions after PAO. Methods. This was a single-centre prospective double-blind placebo-controlled randomized trial of 81 patients aged 12 to 45 years undergoing elective PAO by a single surgeon. The intervention group (n = 40) received two doses of IV TXA of a maximum 1 g in each dose; the control group (n = 41) received two doses of 50 ml 0.9% saline IV. The primary outcome was perioperative calculated blood loss. Secondary outcomes included allogenic transfusions and six-week postoperative complications. Results. There were no differences in demographics or intraoperative variables between study groups. The TXA group demonstrated lower mean calculated blood loss (1,265 ml, (SD 321) vs 1,515 ml, (SD 394); p = 0.002) and lower frequency of allogenic transfusion (10%/n = 4 vs 37%/n = 15; p = 0.008). Regression analyses associated TXA use with significant reductions in calculated blood loss (p < 0.001) and transfusion (p = 0.007) after adjusting for age, sex, body mass index, preoperative haemoglobin, cell-saver volume, intraoperative mean arterial blood pressure, and operating time. No patients suffered venous thromboembolic complications. Conclusion. In this trial, IV TXA decreased postoperative calculated blood loss by 293 ml and reduced the frequency of allogenic transfusions by 73% (37% vs 10%) following PAO. TXA may be safe and effective for reducing blood loss in patients undergoing PAO. Cite this article: Bone Joint J 2020;102-B(9):1151–1157

Aims. Responsiveness and ceiling effects are key properties of an outcome score. No such data have been reported for the original English version of the International Hip Outcome Tool 12 (iHOT-12) at a follow-up of more than four months. The aim of this study was to identify the responsiveness and ceiling effects of the English version iHOT-12 in a series of patients undergoing hip arthroscopy for intra-articular hip pathology at a minimum of one year postoperatively. Methods. A total of 171 consecutive patients undergoing hip arthroscopy with a diagnosis of femoroacetabular impingement (FAI) under the care of a single surgeon between January 2013 and March 2017 were included. iHOT-12 and EuroQol 5D-5L (EQ-5D-5L) scores were available pre- and postoperatively. Effect size and ceiling effects for the iHOT-12 were calculated with subgroup analysis. Results. A total of 122 patients (71.3%) completed postoperative PROMs scores with median follow-up of 24.3 months (interquartile range (IQR) 17.2 to 33.5). The median total cohort iHOT-12 score improved significantly from 31.0 (IQR 20 to 58) preoperatively to 72.5 (IQR 47 to 90) postoperatively (p < 0.001). The effect size (Cohen’s d) was 1.59. In all, 33 patients (27%) scored within ten points (10%) of the maximum score and 38 patients (31.1%) scored within the previously reported minimal clinically important difference (MCID) of the maximum score. Furthermore, nine (47%) male patients aged < 30 years scored within 10% of the maximum score and ten (53%) scored within the previously reported MCID of the maximum score. Conclusion. There is a previously unreported ceiling effect of the iHOT-12 at a minimum one-year follow-up which is particularly marked in young, male patients following hip arthroscopy for FAI. This tool may not have the maximum measurement required to capture the true outcome following this procedure. Cite this article: Bone Joint J 2020;102-B(8):1010–1015

Aims. The aim of this study was to analyze the true costs associated with preoperative CT scans performed for robotic-assisted total knee arthroplasty (RATKA) planning and to determine the value of a formal radiologist’s report of these studies. Methods. We reviewed 194 CT reports of 176 sequential patients who underwent primary RATKA by a single surgeon at a suburban teaching hospital. CT radiology reports were reviewed for the presence of incidental findings that might change the management of the patient. Payments for the scans, including the technical and professional components, for 330 patients at two hospitals were also recorded and compared. Results. There were 82 incidental findings in 61 CT studies, one of which led to a recommendation for additional testing. Across both institutions, the mean total payment for a preoperative scan was $446 ($8 to $3,870). The mean patient payment was $71 ($0 to $2,690). There was wide variation in payments between the institutions. In Institution A, the mean total payment was $258 ($168 to $264), with a mean patient payment of $57 ($0 to $100). The mean technical payment in this institution was $211 ($8 to $856), while the mean professional payment was $48 ($0 to $66). In Institution B, the mean total payment was $636 ($37 to $3,870), with a mean patient payment of $85 ($0 to $2,690). Conclusion. The total cost of a CT scan is low and a minimal part of the overall cost of the RATKA. No incidental findings identified on imaging led to a change in management, suggesting that the professional component could be eliminated to reduce costs. Further studies need to take into account the patient perspective and the wide variation in total costs and patient payments across institutions and insurances. Cite this article: Bone Joint J 2020;102-B(6 Supple A):79–84

Aims. A number of methods have been described to remove a well-fixed humeral implant as part of revision shoulder arthroplasty. These include the use of cortical windows and humeral osteotomies. The router bit extraction technique uses a high-speed router bit to disrupt the bone-implant interface. The implant is then struck in a retrograde fashion with a square-tip impactor and mallet. The purpose of this study was to determine the characteristics and frequency of the different techniques needed for the removal of a well-fixed humeral stem in revision shoulder arthroplasty. Patients and Methods. Between 2010 and 2018, 288 revision shoulder arthroplasty procedures requiring removal of a well-fixed humeral component were carried out at a tertiary referral centre by a single surgeon. The patient demographics, indications for surgery, and method of extraction were collected. Results. Of the 288 revisions, 284 humeral stems (98.6%) were removed using the router bit extraction technique alone. Four humeral stems (1.39%) required an additional cortical window. Humeral osteotomy was not necessary in any procedure. Most of the humeral stems removed (78.8%) were cementless. Of the four humeral stems that required a cortical window, three involved removal of a hemiarthroplasty. Two were cemented and two were cementless. Conclusion. The router bit extraction technique removed a well-fixed humeral component in a very high proportion of patients (98.6%). This method allows surgeons to avoid more invasive approaches involving a cortical window or humeral osteotomy, and their associated complications. Cite this article: Bone Joint J 2019;101-B:1280–1284

Aims. A significant percentage of patients remain dissatisfied after total knee arthroplasty (TKA). The aim of this study was to determine whether the sequential addition of accelerometer-based navigation for femoral component preparation and sensor-guided ligament balancing improved complication rates, radiological alignment, or patient-reported outcomes (PROMs) compared with a historical control group using conventional instrumentation. Methods. This retrospective cohort study included 371 TKAs performed by a single surgeon sequentially. A historical control group, with the use of intramedullary guides for distal femoral resection and surgeon-guided ligament balancing, was compared with a group using accelerometer-based navigation for distal femoral resection and surgeon-guided balancing (group 1), and one using navigated femoral resection and sensor-guided balancing (group 2). Primary outcome measures were Patient-Reported Outcomes Measurement Information System (PROMIS) and Knee injury and Osteoarthritis Outcome (KOOS) scores measured preoperatively and at six weeks and 12 months postoperatively. The position of the components and the mechanical axis of the limb were measured postoperatively. The postoperative range of motion (ROM), haematocrit change, and complications were also recorded. Results. There were 194 patients in the control group, 103 in group 1, and 74 in group 2. There were no significant differences in baseline demographics between the groups. Patients in group 2 had significantly higher baseline mental health subscores than control and group 1 patients (53.2 vs 50.2 vs 50.2, p = 0.041). There were no significant differences in any PROMs at six weeks or 12 months postoperatively (p > 0.05). There was no difference in the rate of manipulation under anaesthesia (MUA), complication rates, postoperative ROM, or blood loss. There were fewer mechanical axis outliers in groups 1 and 2 (25.2%, 14.9% respectively) versus control (28.4%), but this was not statistically significant (p = 0.10). Conclusion. The sequential addition of navigation of the distal femoral cut and sensor-guided ligament balancing did not improve short-term PROMs, radiological outcomes, or complication rates compared with conventional techniques. The costs of these added technologies may not be justified. Cite this article: Bone Joint J 2020;102-B(6 Supple A):24–30

Aims. The purpose of this study was to determine the functional outcome and implant survivorship of mobile-bearing total ankle arthroplasty (TAA) performed by a single surgeon. Patients and Methods. We reviewed 205 consecutive patients (210 ankles) who had undergone mobile-bearing TAA (205 patients) for osteoarthritis of the ankle between January 2005 and December 2015. Their mean follow-up was 6.4 years (2.0 to 13.4). Functional outcome was assessed using the Ankle Osteoarthritis Scale, American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, 36-Item Short-Form Health Survey (SF-36) score, visual analogue scale, and range of movement. Implant survivorship and complications were also evaluated. Results. There were significant improvements in all functional outcome categories between the preoperative and final follow-up assessments (p < 0.001). Patients showed marked improvement in clinical outcomes in terms of pain, function, and quality of life. The overall implant survivorship was 91.7% at a mean follow-up of 6.4 years. In all, 33 major complications were identified with a 15.7% rate, resulting in 12 prosthesis failures (5.7%). Periprosthetic osteolysis (19 cases; 9.0%) was the most frequent complication. Conclusion. Mobile-bearing TAA resulted in improved functional outcomes, a low major complication rate, and excellent implant survivorship at a mean follow-up of 6.4 years. Cite this article: Bone Joint J 2019;101-B:695–701