Introduction. THR is one of the most frequently performed operations nationally. A large number of prostheses are available, and the procedure is therefore associated with variation in practice and outcomes. NICE guidelines aim to standardise best practice, and are informed by separate, independent bodies, such as the NJR and ODEP, which monitor data about the implants used and their performance. This study aims to determine whether clinical practice and component use has changed since the publication of NJR data. Methods. NJR reports from 2006–2014 were analysed, with record made of the different prostheses used in THR, noting ODEP ratings of components used. Analysis was also performed by component type (i.e. cemented and cementless stems and cups), and combinations of components, according to their frequency of use in a given year. The Kruksal-Wallis test was used for statistical analysis. Results. Analysis revealed that the number of components used with an A ODEP rating has increased from 2006–2014. However, there was no significant change (p=0.37) in the use of these components when expressed as a percentage of total procedures performed. Use of ODEP B, C and unclassified prostheses does not appear to have declined. During the period of study there has been a 9% rise in the number of implant combinations used, and a 37.9% rise in the number of implant combinations used fewer than 10 times annually, though these procedures now account for a lower percentage of the total performed annually. Discussion. Our analysis demonstrates that there has been limited change in practice since the publication of NJR data. A large variety of implants and products persist without evidence of long-term success. Furthermore, many components are used infrequently, raising concerns that surgeons may be less familiar with their nuances. There is a significant risk of higher costs due to increased primary expenditure and complications leading to avoidable, early revision. Conclusion. We conclude that NJR data publication does not directly influence clinical practice

Introduction

Magnetic resonance arthrogram (MRA) is the investigation of choice in young adults with symptoms of femero acetabular impingement. The aim of the study is to assess the accuracy of MRA when correlated with surgical findings on hip arthroscopy.

Aims. The aim of this study was to estimate the clinical and economic burden of dislocation following primary total hip arthroplasty (THA) in England. Methods. This retrospective evaluation used data from the UK Clinical Practice Research Datalink database. Patients were eligible if they underwent a primary THA (index date) and had medical records available 90 days pre-index and 180 days post-index. Bilateral THAs were excluded. Healthcare costs and resource use were evaluated over two years. Changes (pre- vs post-THA) in generic quality of life (QoL) and joint-specific disability were evaluated. Propensity score matching controlled for baseline differences between patients with and without THA dislocation. Results. Among 13,044 patients (mean age 69.2 years (SD 11.4), 60.9% female), 191 (1.5%) had THA dislocation. Two-year median direct medical costs were £15,333 (interquartile range (IQR) 14,437 to 16,156) higher for patients with THA dislocation. Patients underwent revision surgery after a mean of 1.5 dislocations (1 to 5). Two-year costs increased to £54,088 (IQR 34,126 to 59,117) for patients with multiple closed reductions and a revision procedure. On average, patients with dislocation had greater healthcare resource use and less improvement in EuroQol five-dimension index (mean 0.24 (SD 0.35) vs 0.44 (SD 0.35); p < 0.001) and visual analogue scale (0.95 vs 8.85; p = 0.038) scores, and Oxford Hip Scores (12.93 vs 21.19; p < 0.001). Conclusion. The cost, resource use, and QoL burden of THA dislocation in England are substantial. Further research is required to understand optimal timing of revision after dislocation, with regard to cost-effectiveness and impact on QoL. Cite this article: Bone Joint J 2022;104-B(7):811–819

The objective of this study is to evaluate the effectiveness and safety of percutaneous tenotomy of the iliopsoas tendon with the aid of ultrasound in cadavers. An anatomical and descriptive study of the technique of percutaneous tenotomy of the iliopsoas tendon guided by ultrasound and to share our experience in performing it and its reproducibility in clinical practice. Out of 20 tenotomies, 17 were total, performed at the level of the superior border of the acetabulum. Three tenotomies were partial, with more than 75% of the tendon being sectioned in all three. During one of the tenotomies, there was a partial injury to the femoral nerve. Measurements were made of the distance between the site where the blade was inserted and the femoral nerve, a noble structure that would be at greater risk during the procedure, with an average distance of 8.4 millimeters. Ultrasound-guided iliopsoas tendon release procedures have the ability to be performed in a cadaveric model, consistently achieving complete tendon release, except in cases of obesity, with minimal repercussions on adjacent structures, and require approximately 4 minutes to complete

Aims. Periprosthetic hip-joint infection is a multifaceted and highly detrimental outcome for patients and clinicians. The incidence of prosthetic joint infection reported within two years of primary hip arthroplasty ranges from 0.8% to 2.1%. Costs of treatment are over five-times greater in people with periprosthetic hip joint infection than in those with no infection. Currently, there are no national evidence-based guidelines for treatment and management of this condition to guide clinical practice or to inform clinical study design. The aim of this study is to develop guidelines based on evidence from the six-year INFection and ORthopaedic Management (INFORM) research programme. Methods. We used a consensus process consisting of an evidence review to generate items for the guidelines and online consensus questionnaire and virtual face-to-face consensus meeting to draft the guidelines. Results. The consensus panel comprised 21 clinical experts in orthopaedics, primary care, rehabilitation, and healthcare commissioning. The final output from the consensus process was a 14-item guideline. The guidelines make recommendations regarding increased vigilance and monitoring of those at increased risk of infection; diagnosis including strategies to ensure the early recognition of prosthetic infection and referral to orthopaedic teams; treatment, including early use of DAIR and revision strategies; and postoperative management including appropriate physical and psychological support and antibiotic strategies. Conclusion. We believe the implementation of the INFORM guidelines will inform treatment protocols and clinical pathways to improve the treatment and management of periprosthetic hip infection. Cite this article: Bone Jt Open 2023;4(4):226–233

The painful hip without obvious clinical or radiographic signs of complications is a well-known scenario for surgeons. The clinical tools we have access to currently lack a dynamic test for detecting early signs of motion between implant and bone. A new software, Sectra IMA, has a potential to facilitate diagnosis of early implant loosening by analysis of paired CT exams. In clinical practise the two scans are acquired by endpoint of a possible motion, “a provocation CT”, for example maximal external and internal rotation in a CT hip examination. 20 years of research by Olivecrona and Weidenhielm is the scientific background for the technique. Early results are presented by Sandberg et al 2022. To further validate and create clinical evidence more extensive clinical studies is needed. A proposal for a multicentric, global clinical study will be presented for further discussion. A new technique for diagnosis of acetabular cup loosening using computed tomography: preliminary experience in 10 patients. Henrik Olivecrona, Lotta Olivecrona, Lars Weidenhielm, Marilyn E Noz, Jocelyn Kardos, Gerald Q Maguire Jr, Michael P Zeleznik, Peter Aspelin. Acta Orthop. 2008 Jun;79(3):346-53. doi: 10.1080/17453670710015247. Inducible displacement CT increases the diagnostic accuracy of aseptic loosening in primary total hip arthroplasty. Sandberg O, Carlsson S, Harbom E, Cappelen V, Tholén S, Olivecrona H, Wretenberg P. Acta Orthop. 2022 Oct 31;93:831-836. doi: 10.2340/17453674.2022.5240.PMID: 36314542

Elevated synovial leukocyte count is a minor criterion derived from the musculoskeletal infection society (MSIS) widely used in clinical practice for diagnosis of prosthetic joint infection. There is evidence to suggest analysis within 1 hour, preferentially within 30 minutes, of aspiration reduces the risk of ex vivo cell lysis occurring during prolonged transport. Multiple site working is more common practice and the availability of a lab on site to perform these tests is not always possible. We aimed to assess whether we could safely perform synovial leukocyte counts within our cold site in the diagnosis of prosthetic joint infection. We reviewed all orthopaedic synovial fluid aspirates within the lower limb arthroplasty unit from April 2021 – April 2022 performed at South Tees NHS Foundation Trust. We assessed time from aspirate to the lab using electronic data resources. This information was compared with the labs ability to perform a synovial leukocyte count to determine the impact of delays on testing. 110 patients (34.5% hips and 63.6% knees) were identified between two sites. Time from aspirate to lab ranged from 0 mins to 26 hrs 34 mins. Mean time to processing was 3hrs 10 mins. 50% of all samples had a synovial leukocyte count performed. 67% of patients had a cell differential performed. There was no difference in the ability to perform a synovial leukocyte count between samples process in < 2hours vs > 6 hours. We conclude that it is safe practice to perform joint aspirates for the work up of periprosthetic joint infections in sites where no laboratory is immediately available as the delay to processing synovial fluid does not alter the ability to perform a synovial leukocyte count. This study will provide evidence to enable the work up of periprosthetic joint infections in cold centres and therefore reduce the delay in diagnosis and proceeding management

Given the prolonged waits for hip arthroplasty seen across the U.K. it is important that we optimise priority systems to account for potential disparities in patient circumstances and impact. We set out to achieve this through a two-stage approach. This included a Delphi-study of patient and surgeon preferences to determine what should be considered when determining patient priority, followed by a Discrete Choice Experiment (DCE) to decide relative weighting of included attributes. The study was conducted according to the published protocol ([. https://boneandjoint.org.uk/article/10.1302/2633-1462.310.BJO-2022-0071. ](. https://boneandjoint.org.uk/article/10.1302/2633-1462.310.BJO-2022-0071. )). The Delphi study was performed online over 3 rounds with anonymous ranking and feedback. Included factors were voted as either Consensus in, Consensus out, or No Consensus• following an established scoring criterion. A final consensus meeting determined the prioritisation factors (and their levels) to be included in the DCE. The DCE was then conducted using an online platform, with surgeons performing 18 choice sets regarding which merited greater priority between two hypothetical patients. Results were collated and analysed using multinomial logit regression analysis (MNL). For the Delphi study there were 43 responses in the first round, with a subsequent 91% participation rate. Final consensus inclusion was achieved for Pain; Mobility/Function; Activities of Daily Living; Inability to Work/Care; Length of Time Waited; Radiological Severity and Mental Wellbeing. 70 individuals subsequently contributed to the DCE, with radiological severity being the most significant factor (Coefficient 2.27 \[SD 0.31\], p<0.001), followed by pain (Coefficient 1.08 \[SD 0.13\], p<0.001) and time waited (Coefficient for 1-month additional wait 0.12 \[SD 0.02\], p<0.001). The calculated trade-off in waiting time for a 1-level change in pain (e.g., moderate to severe pain) was 9.14 months. These results present a new method of determining comparative priority for those on primary hip arthroplasty waiting lists. Evaluation of potential implementation in clinical practice is now required

Aims. To establish whether there was a consensus among the members of the Hip Society (HS) on the role of direct anterior approach (DAA) contemporary primary total hip arthroplasty (THA). Methods. An online survey was sent to all 112 active and senior members of the HS, to which 71 members responded. The survey was constructed to determine whether they believed that evidence-based medicine proves, in modern clinical practice, that the DAA has significant benefits compared to risks when contrasted with other approaches. In addition, they were asked if they currently used the DAA. Results. While only 16.9% (12/71) of respondents had been trained in a generic anterior approach during residency, 49.3% (35/71) had used the DAA in their clinical practice in the past or were using it at the present time. Unexpectedly, 42.9% (15/35) of respondents who had used the DAA in the past had abandoned it by the time of this survey. Only 22.5% (16/71) of all respondents believed that evidence-based medicine proves that the DAA has significant benefits compared to risks in contrast to other approaches. Conclusion. A comprehensive literature review found only three prospective randomized clinical trials (RCT) comparing the DAA with another approach with greater than one-year follow-up. Two showed minor benefits within the early postoperative period only, and one of those showed poorer mid-term results. Most of the published comparison studies with short follow-up show longer surgical times and greater blood loss for the DAA, and many three-month comparison studies show higher complication rates for the DAA using a proprietary traction table. The complications included problems with wound healing, lateral femoral cutaneous nerve injury, femoral component loosening, and femoral fractures. Because of the lack of evidence from RCTs showing superiority of the DAA over other approaches and reports of higher complications, the opinion of a large majority (77.5%; 55/71) of HS surgeons was that the DAA lacks sufficient evidence to warrant its use. Cite this article: Bone Joint J 2020;102-B(7 Supple B):57–61

Aims. To determine if primary cemented acetabular component geometry (long posterior wall (LPW), hooded, or offset reorientating) influences the risk of revision total hip arthroplasty (THA) for instability or loosening. Methods. The National Joint Registry (NJR) dataset was analyzed for primary THAs performed between 2003 and 2017. A cohort of 224,874 cemented acetabular components were included. The effect of acetabular component geometry on the risk of revision for instability or for loosening was investigated using log-binomial regression adjusting for age, sex, American Society of Anesthesiologists grade, indication, side, institution type, operating surgeon grade, surgical approach, polyethylene crosslinking, and prosthetic head size. A competing risk survival analysis was performed with the competing risks being revision for other indications or death. Results. The distribution of acetabular component geometries was: LPW 81.2%; hooded 18.7%; and offset reorientating 0.1%. There were 3,313 (1.5%) revision THAs performed, of which 815 (0.4%) were for instability and 838 (0.4%) were for loosening. Compared to the LPW group, the adjusted subhazard ratio of revision for instability in the hooded group was 2.31 (p < 0.001) and 4.12 (p = 0.047) in the offset reorientating group. Likewise, the subhazard ratio of revision for loosening was 2.65 (p < 0.001) in the hooded group and 13.61 (p < 0.001) in the offset reorientating group. A time-varying subhazard ratio of revision for instability (hooded vs LPW) was found, being greatest within the first three months. Conclusion. This registry-based study confirms a significantly higher risk of revision after cemented THA for instability and for loosening when a hooded or offset reorientating acetabular component is used, compared to a LPW component. Further research is required to clarify if certain patients benefit from the use of hooded or offset reorientating components, but we recommend caution when using such components in routine clinical practice. Cite this article: Bone Joint J 2021;103-B(11):1669–1677

To estimate the clinical and economic burden of primary total hip arthroplasty (THA) dislocation in England. Retrospective propensity score-matched evaluation of patients with and without dislocation following primary THA using the UK Clinical Practice Research Datalink linked and Hospital Episode Statistics datasets with a 2-year follow-up. 13,044 patients with total hip replacements met the inclusion criteria (mean age 69.2, 60.9% female) of which 154 (1.18%) suffered at least one postoperative hip dislocation. The mean number of dislocations per patient was 1.44 with a maximum of 4. Approximately one-third of the patients with dislocation (32.5%) had more than one dislocation. Among patients with a hip dislocation 148 patients (96.7%) had at least one closed reduction and 20 patients (13.1%) had revision surgery. Two-year median direct medical costs were £14,748 (95% confidence interval [CI] £12,028 to £20,638) higher with vs. without dislocation (+227%). On average, patients with a dislocation had significantly greater healthcare resource utilization and significantly less improvement in EuroQol-5D (EQ-5D) index (0.24 vs. 0.45; p<0.001) and Visual Analogue Scale (VAS) (1.58 vs. 11.23; p=0.010) scores and Oxford Hip Scores (13.02 vs. 21.98; p<0.001). This is the first study to estimate the economic burden of dislocation in the UK throughout the entire patient pathway. Dislocation following total hip replacement is a costly complication, both in terms of economic costs and to the functional quality of life of the patient. Efforts to reduce the risks of dislocation should remain at the forefront of hip research

Hip fractures are associated with poor outcomes and high mortality rates of 30%. The current gold standard to measure bone fragility is a Dual-Energy X-ray Absorptiometry (DEXA) scan measuring bone mineral density. Yet DEXA under-diagnoses bone fragility by 50% (1). To combat the burden of bone fragility, this experimental study combined ultrasound (US) with a sophisticated computational algorithm, namely full wave inversion (FWI), to evaluate femoral bone structure. The aims were to assess the association of bone structure between the proximal femoral diaphysis and femoral neck; secondly to evaluate whether transverse ultrasound could assess bone structure of the proximal femoral diaphysis. Bone structure of 19 ex vivo human femora was assessed by micro-CT analysis (mean age 88.11 years, male:female 13:6)(Nikon HMXST 225). Using ImageJ/BoneJ, three 10.2mm subsections of proximal diaphysis and femoral neck underwent analysis: the total bone volume fraction, cortical parameters (bone volume fraction, porosity, thickness) and trabecular parameters (porosity, thickness, spacing and connectivity). A unique US prototype was developed to analyse fifteen femoral diaphyseal subsections using two P4-1 transducers with a novel tomography sequence (Verasonics, Matlab ver R2019a, FWI TRUST protocol). Comparative quantitative analysis of US and Micro-CT measurements was assessed (Graphpad Prism 8.3.1). Micro-CT analysis of the proximal femoral diaphysis demonstrated low correlation to the femoral neck (Pearson r −0.54 to 0.55). US was able to capture cortical structure, though a wide limit of agreement seen when compared to micro-CT analysis (Bland-Altman range 36–59% difference). This novel US technique was able to capture cortical bone structure. Improvements in methodology and technology are required to improve the analysis of trabecular bone and overall accuracy. Further evaluation of US and FWI is required to develop the technique and determine its role in clinical practice

Cemented acetabular components commonly have a long posterior wall (LPW). Alternative components have a hooded or offset reorientating geometry, theoretically to reduce the risk of THR instability. We aimed to determine if cemented acetabular component geometry influences the risk of revision surgery for instability or loosening. The National Joint Registry for England, Wales and Northern Ireland (NJR) dataset was analysed for primary THAs performed between 2003 – 2017. A cohort of 224,874 cemented acetabular components were identified. The effect of acetabular component geometry on the risk of revision for instability or for loosening was investigated using binomial regression adjusting for age, gender, ASA grade, diagnosis, side, institution type, operating surgeon grade, surgical approach, polyethylene crosslinking and head size. A competing risk survival analysis was performed with the competing risks being revision for other indications or death. Among the cohort of subjects included, the distribution of acetabular component geometries was: LPW – 81.2%, hooded – 18.7% and offset reorientating – 0.1%. There were 3,313 (1.47%) revision THAs performed, of which 815 (0.36%) were for instability and 838 (0.37%) were for loosening. Compared to the LPW group, the adjusted subhazard ratio of revision for instability in the hooded group was 2.29 (p<0.001) and 4.12 (p=0.047) in the offset reorientating group. Likewise, the subhazard ratio of revision for loosening was 2.43 (p<0.001) in the hooded group and 11.47 (p<0.001) in the offset reorientating group. A time-varying subhazard ratio of revision for instability (hooded vs LPW) was found, being greatest within the first 6 months. This Registry based study confirms a significantly higher risk of revision THA for instability and for loosening when a cemented hooded or offset reorientating acetabular component is used, compared to an LPW component. Further research is required to clarify if certain patients benefit from the use of hooded or offset reorientating components, but we recommend caution when using such components in routine clinical practice

Due to limitations of existing pharmacological therapies for the management of chronic pain in osteoarthritis (OA), surgical interventions remain a major component of current standard of care, with total joint replacements (TJRs) considered for people who have not responded adequately to conservative treatment. This study aimed to quantify the economic burden of moderate-to-severe chronic pain in patients with OA in England prior to TJR. A retrospective, longitudinal cohort design was employed using Clinical Practice Research Datalink GOLD primary care data linked to Hospital Episode Statistics secondary care data in England. Patients (age ≥18 years) with an existing OA diagnosis of any anatomical site (Read/ICD-10) were indexed (Dec-2009 to Nov-2017) on a moderate-to-severe pain event (which included TJR) occurring within an episode of chronic pain. 5-year TJR rates from indexing were assessed via Kaplan-Meier estimates. All-cause healthcare resource utilisation and direct medical costs were evaluated in the 1–12 and 13–24 months prior to the first TJR experienced after index. Statistical significance was assessed via paired t-tests. The study cohort comprised 5,931 eligible patients (57.9% aged ≥65 years, 59.2% female). 2,176 (36.7%) underwent TJR (knee: 54.4%; hip: 42.8%; other: 2.8%). The 5-year TJR rate was 45.4% (knee: 24.3%; hip: 17.5%; other: 6.8%). Patients experienced more general practitioner consultations in 1–12 months pre-TJR compared with 13–24 months pre-TJR (means: 12.13 vs. 9.61; p<0.0001), more outpatient visits (6.68 vs. 3.77; p<0.0001), more hospitalisations (0.74 vs. 0.62; p=0.0032), and more emergency department visits (0.29 vs. 0.25, p=0.0190). Total time (days) spent as an inpatient was higher in 1–12 months pre-TJR (1.86 vs. 1.07; p<0.0001). Mean total per-patient cost pre-TJR increased from £1,771 (13–24 months) to £2,621 (1–12 months) (p<0.0001). Resource-use and costs incurred were substantially greater in the 12 months immediately prior to TJR, compared with 13–24 months prior. Reasons for increased healthcare and economic burden in the pre-TJR period deserve further exploration as potential targets for efforts to improve patient experience and efficiency of care

Aims. The aim of this study was to investigate the differences in 30-day outcomes between patients undergoing revision for an infected total hip arthroplasty (THA) compared with an aseptic revision THA. Patients and Methods. This was a retrospective review of prospectively collected data from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database, between 2012 and 2017, using Current Procedural Terminology (CPT) codes for patients undergoing a revision THA (27134, 27137, 27138). International Classification of Diseases Ninth Revision/Tenth Revision (ICD-9-CM, ICD-10-CM) diagnosis codes for infection of an implant or device were used to identify patients undergoing an infected revision THA. CPT-27132 coupled with ICD-9-CM/ICD-10-CM codes for infection were used to identify patients undergoing a two-stage revision. A total of 13 556 patients were included; 1606 (11.8%) underwent a revision THA due to infection and there were 11 951 (88.2%) aseptic revisions. Results. Patients undergoing an infected revision had a significantly greater length of stay of more than three days (p < 0.001), higher odds of any 30-day complication (p < 0.001), readmission within 30 days (p < 0.001), 30-day reoperations (p < 0.001), and discharge to a destination other than the patient’s home (p < 0.001). Conclusion. The findings suggest the need for enhanced risk adjustment based on the indication of revision THA prior to setting prices in bundled payment models of total joint arthroplasty. This risk adjustment should be used to reduce the chance of financial disincentives in clinical practice. Cite this article: Bone Joint J 2019;101-B:547–551

Objectives. The determination of the volumetric polyethylene wear on explanted material requires complicated equipment, which is not available in many research institutions. Our aim in this study was to present and validate a method that only requires a set of polyetheretherketone balls and a laboratory balance to determine wear. Methods. The insert to be measured was placed on a balance, and a ball of the appropriate diameter was inserted. The cavity remaining between the ball and insert caused by wear was filled with contrast medium and the weight of the contrast medium was recorded. The volume was calculated from the known density of the liquid. The precision, inter- and intraobserver reliability, were determined by four investigators on four days using nine inserts with specified wear (0.094 ml to 1.626 ml), and the intra-class correlation coefficient was calculated. The feasibility of using this method in routine clinical practice and the time required for measurement were tested on 84 explanted inserts by one investigator. Results. In order to get the mean for all investigators and determinations, the deviation between the measured and specified wear was -0.08 ml . (sd. 0.12; -0.21 to 0.11). The interobserver reliability was 0.989 ml (95% confidence interval (CI) 0.964 to 0.997) and the intraobserver reliability was 0.941 for observer 1 (95% CI 0.846 to 0.985), 0.983 for observer 2 (95% CI 0.956 to 0.995), 0.939 for observer 3 (95% CI 0.855 to 0.984), and 0.934 for observer 4 (95% CI 0.790 to 0.984). The mean time required to examine the samples was two minutes . (sd. 2; 1 to 5). Conclusion. The method presented here was shown to be sufficiently precise for many settings and is a cost-effective and quick method of determining the volumetric wear of explanted acetabular components. However, the measurement of wear for scientific purposes will probably continue to involve more accurate and dedicated laboratory equipment. Cite this article: Bone Joint Res 2017;6:530–534

Objectives. The annual incidence of hip fracture is 620 000 in the European Union. The cost of this clinical problem has been estimated at 1.75 million disability-adjusted life years lost, equating to 1.4% of the total healthcare burden in established market economies. Recent guidance from The National Institute for Health and Clinical Excellence (NICE) states that research into the clinical and cost effectiveness of total hip arthroplasty (THA) as a treatment for hip fracture is a priority. We asked the question: can a trial investigating THA for hip fracture currently be delivered in the NHS?. Methods. We performed a contemporaneous process evaluation that provides a context for the interpretation of the findings of WHiTE Two – a randomised study of THA for hip fracture. We developed a mixed methods approach to situate the trial centre within the context of wider United Kingdom clinical practice. We focused on fidelity, implementation, acceptability and feasibility of both the trial processes and interventions to stakeholder groups, such as healthcare providers and patients. Results. We have shown that patients are willing to participate in this type of research and that surgeons value being part of a team that has a strong research ethos. However, surgical practice does not currently reflect NICE guidance. Current models of service delivery for hip fractures are unlikely to be able to provide timely total hip arthroplasty for suitable patients. Conclusions. Further observational research should be conducted to define the population of interest before future interventional studies are performed. Cite this article: C. Huxley, J. Achten, M. L. Costa, F. Griffiths, X. L. Griffin. A process evaluation of the WHiTE Two trial comparing total hip arthroplasty with and without dual mobility component in the treatment of displaced intracapsular fractures of the proximal femur: Can a trial investigating total hip arthroplasty for hip fracture be delivered in the NHS? Bone Joint Res 2016;5:444–452. DOI: 10.1302/2046-3758.510.BJR-2015-0008.R1

The principle function of the “short external rotator” muscle group is primarily as an abductor and extensor of the flexed hip and is better referred to as the “Quadriceps Coxa” (QC). The QC has a profound influenced on weight bearing rising and propulsive motions. The SPAIRE technique preserves Obturator Internus (OI) and Piriformis (P) resulting in improved stability of the hip and potentially improved recovery and function in patients undergoing hip arthroplasty. Short term outcomes of the first 42 consecutive SPAIRE cases are compared with 86 consecutive cases using the traditional posterior approach that immediately preceded introduction of the technique. The purpose was to document the learning curve and confirm the safety of introducing SPAIRE into routine clinical practice. The two groups were comparable and there was no statistically significant difference in length of stay, blood loss, intra-or post-operative complications nor radiological measurements relating to the femoral or acetabular components. Statistically significant differences were found for component usage (more uncemented acetabula for SPAIRE), length of operation (8 mins longer with SPAIRE); patient satisfaction was higher at 6 weeks and measured leg length discrepancy less in the SPAIRE group. SPAIRE has been used routinely for all routine arthroplasties for over two years. RCTs are ongoing to document the effect of SPAIRE on recovery, long term function and activity level. If the potential benefits are confirmed SPAIRE may become the default technique for hip arthroplasty operations through a posterior approach for elective and hip fracture cases

Introduction. Smoking, a modifiable factor, may adversely affect post-operative outcomes. Healthcare providers are increasingly denying smokers access to total hip arthroplasty (THA) until they stop smoking. Evidence supporting this is unclear. We assessed the effect of smoking on outcomes following THA. Patients and Methods. We performed a retrospective observational study involving 60,812 THAs (12.4%=smokers, 31.2%=ex-smokers, 56.4%=non-smokers) from the Clinical Practice Research Datalink. Data were linked with Hospital Episode Statistics and the Office for National Statistics to identify outcomes. The effect of smoking on post-operative outcomes (complications, medications, revision, mortality, PROMs) was assessed using adjusted regression. Results. Following THA, smokers had a significantly increased risk of lower respiratory tract infection (odds ratio (OR)=0.53; 95% CI=0.43–0.64), myocardial infarction (OR=0.41; CI=0.24–0.71), cerebrovascular disease (OR=0.54; CI=0.32–0.93), and ischaemic heart disease (OR=0.62; CI=0.43–0.91) compared with non-smokers. The risk of these complications in smokers was also significantly higher compared with ex-smokers. The risk of other complications, including DVT and wound infection, was similar between smoking groups. Compared with non-smokers (OR=0.55; CI=0.51–0.60) and ex-smokers (OR=0.85; CI=0.78–0.92), smokers had increased opioid usage at one-year post-surgery. Similar patterns were observed for weak opioids and paracetamol. One-year mortality rates were higher in smokers compared with non-smokers (hazard ratio (HR)=0.39, CI=0.30–0.50) and ex-smokers (HR=0.50, CI=0.39–0.65). Long-term revision rates were not increased in smokers. Smokers had significant improvement in PROMs compared with pre-operatively, with no clinically important difference in postoperative PROMs between smokers, non-smokers and ex-smokers. Discussion. Smoking was associated with more medical complications (namely vascular), higher analgesia usage, and increased mortality following THA. Most adverse outcomes were reduced in ex-smokers, therefore smoking cessation should be encouraged before arthroplasty. However, THA is clinically effective in smokers, who gain meaningful PROM improvement with no increased revision risk. Conclusion. Smokers should not be universally denied access to primary THA

Leukocyte esterase (LE) has shown to be an accurate marker of prosthetic joint infections and has been proposed as an alternative to frozen section (FS) for intra-operative diagnosis. In this study, intra-operative determination of LE was compared with FS for the diagnosis of periprosthetic hip infections. One hundred and nineteen patients undergoing hip revision surgery due to prosthetic joint failure from June 2015 to December 2017 were considered. Joint fluids were collected before the arthrotomy for determination of LE which was performed by using enzymatic colorimetric strips. Four to six samples were stained with hematoxylin eosin for FS and considered suggestive for infection when at least 5 polymorphonuclear leukocytes in 5 fields at high power fields were found. Sensitivity and specificity of LE were 100% and 93.8 %, respectively. The positive predictive value was 79.3 %, while the negative predictive value was 100%. Time from collection to response was 20.1 ± 4.4 minutes. Sensitivity and specificity of FS were 83.3 % and 92.1 %, respectively. The positive and negative predictive values were 84.6 % and 97.1%. Time from sample collection response was 27.2 ± 6.9 minutes. LE showed a higher sensitivity and a slightly lower specificity and the same diagnostic accuracy of intraoperative FS. The faster turnaround time (about 20 minutes from receiving of sample by the laboratory), its ease of use and the low costs make this test a valuable alternative to frozen sections and is going to replace FS in our clinical practice