Purpose. Great expense is accumulated in investigation and management, often with poor outcome, of a patient with a painful TKR. We aim to produce guidelines for their investigation and careful, successful management. Method. We studied 42 cases of patients with a painful TKR. Costs were calculated of appointments, serological and radiological investigations for these patients and an average cost of investigating a patient was obtained. We also calculated costs of various forms of management, both surgical and non-surgical and correlated these with patient outcomes. Results. 41 patients with an average investigation time of 20 months had on average 4 Orthopaedic appointments for the investigation of a painful TKR. On average, 8 blood tests were performed along with 8 radiographs. The average cost of investigating a patient with a painful TKR was £2337. 22 patients underwent operative intervention compared to 19 having solely pharmaceutical intervention. There was a significant difference between the amounts spent in each group with £5051 spent per patient in the operative group compared to £190 per patient on the non-operative group. There was a higher percentage of patient improvement in the non-operative group. Conclusion: Costs for investigation of a patient with a painful TKR were high because of exceedingly high numbers of repeated investigations. There is no guidance currently on how to manage painful TKR which is becoming an increasing clinical problem because of the increasing number of TKR's being performed per year. A lot of money is wasted on over investigating patients and performing operations that do not improve symptoms or prognosis. Careful thought needs to be given to careful investigation and management of patients in order to achieve optimal patient improvement. We have proposed a protocol for the investigation and management that allows prompt diagnosis and intervention and helps improve symptoms while keeping costs down

Aim. This study reviewed the efficacy of a CT arthrogram in clinical decision making for wrist disorders. Methods. Sixty four consecutive CT arthrograms done in a three year period at Glenfield Hospital were selected. All patients were referred by hand consultants at the Glenfield Hospital and all investigations were performed by a single senior musculoskeletal radiologist. CT arthrograms focussed on the following areas: scapholunate interosseous ligament (SLIL), lunotriquetral interosseous ligament (LTIL), peripheral and central triangular fibrocartilage complex (TFCC) tears, and articular surface disorders. Referral and clinic letters for all patients were obtained. We collected patient demographic detail, prescan diagnosis and clinical plan, CT arthrogram findings, postscan diagnosis and clinical plan and the final outcome. A decision was made whether the scan helped in the clinician's management plan and if so how it helped. Results. There were 35 male and 29 female patients with a mean age of 44.1 years. The right wrist was involved in 42 and the left in 22 patients. Sixty three of the 64 patients had their management based on the CT scan. In 54 of these the CT arthrogram either confirmed and calibrated the diagnosis or identified a new diagnosis. In 10 patients the scan was normal and allowed patient reassurance. Thirty six patients had ulnar sided problems, 20 had radial sided disorders and eight had midcarpal abnormality. The most common abnormality noted was a TFCC tear (24). The next most common was chondral damage/arthritis (14) followed by scapholunate interosseous ligament tear (12). The diagnosis was either confirmed and its extent established (31) or identified in addition to the primary diagnosis (19). Conclusions. The CT arthrogram is a helpful tool in the management of intra-articular wrist pathology. We found it to be useful in both confirming and calibrating the diagnosis and also diagnosing occult patho

Introduction

A search of the literature indicates several constrained total knee arthroplasty (TKA) systems are at risk for articular surface lockdown bolts backing out. The backing out of a lockdown bolt may lead to an unstable and/or painful knee and may necessitate revision. Upon backing out, the bolt may damage implant components and surrounding tissues. To date, studies in the literature have not simulated or replicated loosening of bolts in TKA. Therefore, the objectives of this study were to 1) develop a set of physiological loading parameters that challenge bolted articular surfaces; 2) evaluate whether significant bolt torque is lost during application of this loading to a CCK device with a bolt as a secondary locking mechanism.

Objective

To assess the usefulness of radiographs alone to evaluate acute midfoot/forefoot injuries. We believe that foot injuries are often under-estimated and that CT scans should be routinely obtained to aid in their management and avoid additional morbidity for patients.

Background

Spondylolysis (SL) of the lower lumbar spine is frequently associated with spina bifida occulta (SBO). There has not been any study that has demonstrated biomechanical or genetic predispositions to explain the coexistence of these two pathologies.

Ten to twenty percent of patients are dissatisfied with the clinical result after total knee arthroplasty (TKA). Aim of this study was to investigate the impact of personality traits on patient satisfaction and subjective outcome of TKA. We investigated 80 patients with 86 computer navigated TKAs (Emotion®, B Braun Aesculap) and asked for patient satisfaction. We divided patients into two groups (satisfied or dissatisfied). 12 personality traits were tested by an independent psychologist, using the Freiburg Personality Inventory (FPI-R). Postoperative examination included Knee Society Score (KSS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and the Visual Analogue Scale (VAS). Radiologic investigation was done in all patients. 84% of our patients were satisfied, while 16% were not satisfied with clinical outcome. The FPI-R showed statistically significant influence of four personality traits on patient satisfaction: life satisfaction (ρ = 0.006), performance orientation (ρ =0.015), somatic distress (ρ = 0.001), and emotional stability (ρ = 0.002). All clinical scores (VAS, WOMAC, and KSS) showed significant better results in the satisfied patient group. Radiological examination showed optimal alignment of all TKAs. There were no complications requiring revision surgery in both groups. The results of our study show that personality traits may influence patient satisfaction and clinical outcome after TKA. Thus, patients personality traits may be a useful predictive factor for postoperative satisfaction after TKA

Purpose. Intra-articular corticosteroid injection is widely used for symptomatic relief of knee osteoarthritis. However, if pain is not improved which consequences a total knee arthroplasty (TKA), there is a potential risk of post-operative periprosthetic joint infection (PJI). The aim of this study is to investigate whether the use of preoperative intra-articular corticosteroid injection increases the risk of PJI and to investigate a time frame in which the risk of subsequent infection is significantly increased. Methods. A systematic search was performed in PubMed (Medline), Scopus, and the Cochrane Library. Inclusion criteria were original studies investigating the rate of PJI in patients receiving pre-operative intra-articular corticosteroid injection compared to controls. Results. A total of 380 unique articles were screened. Six studies met the inclusion criteria with 255,627 patients in total. Overall, no statistical significance was observed in the intra-articular infection rate in corticosteroid compared to controls groups. However, intra-articular corticosteroid injections within 3 months prior to TKA were associated with a significantly increased risk of infection (OR: 1.52, 95% CI 1.37–1.67, p < 0.01); this was not observed in the 6-month period (OR: 1.05, 95% CI 0.80–1.39, p = 0.72). Conclusions. Performing an intra-articular corticosteroid injection within 3 months prior to TKA is associated with a significantly increased risk of PJI. The current evidence supports the safe use of intra-articular corticosteroid injection more than 6 months before TKA. However, additional studies are needed to clarify the risk of PJI after TKA implantation between 3 and 6 months after the last corticoid injection

Lumbar fusion surgery is an established procedure for the treatment of several spinal pathologies. Despite numerous techniques and existing devices, common surgical trends in lumbar fusion surgery are scarcely investigated. The purpose of this Canada-based study was to provide a descriptive portrait of current surgeons’ practice and implant preferences in lumbar fusion surgery while comparing findings to similar investigations performed in the United Kingdom. Canadian Spine Society (CSS) members were sampled using an online questionnaire which was based on previous investigations performed in the United Kingdom. Fifteen questions addressed the various aspects of surgeons’ practice: fusion techniques, implant preferences, and bone grafting procedures. Responses were analyzed by means of descriptive statistics. Of 139 eligible CSS members, 41 spinal surgeons completed the survey (29.5%). The most common fusion approach was via transforaminal lumber interbody fusion (TLIF) with 87.8% performing at least one procedure in the previous year. In keeping with this, 24 surgeons (58.5%) had performed 11 to 50 cases in that time frame. Eighty-six percent had performed no lumbar artificial disc replacements over their last year of practice. There was clear consistency on the relevance of a patient specific management (73.2%) on the preferred fusion approach. The most preferred method was pedicle screw fixation (78%). The use of stand-alone cages was not supported by any respondents. With regards to the cage material, titanium cages were the most used (41.5%). Published clinical outcome data was the most important variable in dictating implant choice (87.8%). Cage thickness was considered the most important aspect of cage geometry and hyperlordotic cages were preferred at the lower lumbar levels. Autograft bone graft was most commonly preferred (61.0%). Amongst the synthetic options, DBX/DBM graft (64.1%) in injectable paste form (47.5%) was preferred. In conclusion, findings from this study are in partial agreement with previous work from the United Kingdom, but highlight the variance of practice within Canada and the need for large-scale clinical studies aimed to set specific guidelines for certain pathologies or patient categories

Restoration a joint's articular surface following degenerative or traumatic pathology to the osteochondral unit pose a significant challenge. Recent advances have shown the utility of collagen-based scaffolds in the regeneration of osteochondral tissue. To provide these collagen scaffolds with the appropriate superstructure novel techniques in 3D printing have been investigated. This study investigates the use of polyɛ-caprolactone (PCL) collagen scaffolds in a porcine cadaveric model to establish the stability of the biomaterial once implanted. This study was performed in a porcine cadaveric knee model. 8mm defects were created in the medial femoral trochlea and repaired with a PCL collagen scaffold. Scaffolds were secured by one of three designs; Press Fit (PF), Press Fit with Rings (PFR), Press Fit with Fibrin Glue (PFFG). Mobilisation was simulated by mounting the pig legs on a continuous passive motion (CPM) machine for either 50 or 500 cycles. Biomechanical tensile testing was performed to examine the force required to displace the scaffold. 18 legs were used (6 PF, 6 PFR, 6 PFFG). Fixation remained intact in 17 of the cohort (94%). None of the PF or PFFG scaffolds displaced after CPM cycling. Mean peak forces required to displace the scaffold were highest in the PFFG group (3.173 Newtons, Standard deviation = 1.392N). The lowest peak forces were observed in the PFR group (0.871N, SD = 0.412N), while mean peak force observed in the PF group was 2.436N (SD = 0.768). There was a significant difference between PFFG and PFR (p = 0.005). There was no statistical significance in the relationship between the other groups. PCL reinforcement of collagen scaffolds provide an innovative solution for improving stiffness of the construct, allowing easier handling for the surgeon. Increasing the stiffness of the scaffold also allows press fit solutions for reliable fixation. Press fit PCL collagen scaffolds with and without fibrin glue provide dependable stability. Tensile testing provides an objective analysis of scaffold fixation. Further investigation of PCL collagen scaffolds in a live animal model to establish quality of osteochondral tissue regeneration are required

Aims. In the UK, the NHS generates an estimated 25 megatonnes of carbon dioxide equivalents (4% to 5% of the nation’s total carbon emissions) and produces over 500,000 tonnes of waste annually. There is limited evidence demonstrating the principles of sustainability and its benefits within orthopaedic surgery. The primary aim of this study was to analyze the environmental impact of orthopaedic surgery and the environmentally sustainable initiatives undertaken to address this. The secondary aim of this study was to describe the barriers to making sustainable changes within orthopaedic surgery. Methods. A literature search was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines through EMBASE, Medline, and PubMed libraries using two domains of terms: “orthopaedic surgery” and “environmental sustainability”. Results. A total of 13 studies were included in the final analysis. All papers studied the environmental impact of orthopaedic surgery in one of three areas: waste management, resource consumption, and carbon emissions. Waste segregation was a prevalent issue and described by nine studies, with up to 74.4% of hazardous waste being generated. Of this, six studies reported recycling waste and up to 43.9% of waste per procedure was recyclable. Large joint arthroplasties generated the highest amount of recyclable waste per procedure. Three studies investigated carbon emissions from intraoperative consumables, sterilization methods, and through the use of telemedicine. One study investigated water wastage and demonstrated that simple changes to practice can reduce water consumption by up to 63%. The two most common barriers to implementing environmentally sustainable changes identified across the studies was a lack of appropriate infrastructure and lack of education and training. Conclusion. Environmental sustainability in orthopaedic surgery is a growing area with a wide potential for meaningful change. Further research to cumulatively study the carbon footprint of orthopaedic surgery and the wider impact of environmentally sustainable changes is necessary. Cite this article: Bone Jt Open 2022;3(8):628–640

Introduction. The vast majority of orthopaedic surgeons use C-arm fluoroscopy in the operating theatre when building a circular external fixator. In the absence of previous research in this area, we hypothesised that the surgeon who builds a circular external fixator is exposed to a greater amount of radiation purely as a result of the presence of the metallic fixator in the x-ray beam. The aim of our study therefore was to investigate how the presence of a circular external fixator affects the radiation dose to the surgeon and the surgical assistant. Materials & Methods. A simulated environment was created using a radiolucent operating table, an acrylic lower limb phantom (below knee segment), various configurations of metalic circular external fixation, and a standard size C-arm image intensifier. The variables investigated were 1. the amount of metal in the beam 2. the orientation of the beam (PA vertical vs lateral) 3. the horizonal distance of the person from the beam (surgeon vs assistant) and 4. the vertical distance of the various body parts from the beam (e.g. thyroid, groin). In terms of radiation dose, we recorded two things : 1. the dose produced by the image intensifier 2. the dose rate at standardised positions in the operating theatre. The latter was done using a solid-state survey sensor. These positions represented both where the surgeon and surgical assistant typically stand plus the heights of their various body regions relative to the operating table. Results. The effect of the presence of the circular external fixator : all frame constructs tested resulted in a statistically significant greater radiation dose both produced by the image intensifier and received by the surgical team. The effect of the beam orientation : the PA (vertical) orientation resulted in a statistically significant greater radiation dose for the surgeon than did the lateral orientation, but made no difference for the assistant. The effect of horizontal distance from the beam : unsurprisingly, the surgeon (who was closer to the beam) received a statistically significant greater radiation dose than the assistant. The effect of vertical distance from the beam : for the surgeon, the dose received was highest at the level of the phantom leg / frame, whilst for the assistant there was no statistically significant difference for any level. Conclusions. To our knowledge, this is the first study investigating the radiation dose rate to the orthopaedic surgeon when building a circular external fixator. We found that the surgeon does indeed receive a ‘double whammy’ because the image intensifier puts out a greater amount of radiation plus the metalic frame scatters more of the x-ray beam. Whilst the amounts are relatively small, we think that it's important to quantify doses that orthopaedic surgeons receive to ensure optimal radiation practices

The purpose of this study was to investigate the effectiveness of casting in achieving acceptable radiological parameters for unstable ankle injuries. This retrospective observational cohort study was conducted involving the retrieval of X-rays of all ankles taken over a 2 year period in an urban setting to investigate the radiological outcomes of cast management for unstable ankle fractures using four acceptable parameters measured on a single X- ray at union. The Picture Archiving and Communication System (PACS) was used, the X-rays were measured by a single observer. From the 1st of January 2020 to the 31st of December 2021, a total of 1043 ankle fractures were treated at the three hospitals with a male to female ratio of 1:1.7. Of the 628 unstable ankle injuries, 19% of patients were lost to follow up. 190 were managed conservatively with casts, requiring an average of 4 manipulations, with a malunion rate of 23.2%. Unstable ankle injuries that were treated surgically from the outset and those who failed conservative management and subsequently converted to surgery had a malunion rate of 8.1% and 11.0% respectively. Unstable ankle fractures pose a challenge with a high rate of radiological malunion, regardless of the treatment Casting surgery from the outset or converted to surgery, with rates of 23% and 8% and 11% respectively. In this multivariate analysis we found that conservative management was the only factor influencing the incidence of malunion, age, sex and type of fracture did not have a scientific significant influence

Osteoarthritis (OA) is a disease of the synovial joint with synovial inflammation, capsular contracture, articular cartilage degradation, subchondral sclerosis and osteophyte formation contributing to pain and disability. Transcriptomic datasets have identified genetic loci in hip and knee OA demonstrating joint specificity. A limited number of studies have directly investigated transcriptional changes in shoulder OA. Further, gene expression patterns of periarticular tissues in OA have not been thoroughly investigated. This prospective case control series details transcriptomic expression of shoulder OA by analysing periarticular tissues in patients undergoing shoulder replacement for OA as correlated with a validated patient reported outcome measure of shoulder function, an increasing (clinically worsening) QuickDASH score. We then compared transcriptomic expression profiles in capsular tissue biopsies from the OA group (N=6) as compared to patients undergoing shoulder stabilisation for recurrent instability (the control group, N=26). Results indicated that top ranked genes associated with increasing QuickDASH score across all tissues involved inflammation and response to stress, namely interleukins, chemokines, complement components, nuclear response factors and immediate early response genes. Some of these genes were upregulated, and some downregulated, suggestive of a state of flux between inflammatory and anti-inflammatory signalling pathways. We have also described gene expression pathways in shoulder OA not previously identified in hip and knee OA, as well as novel genes involved in shoulder OA

The aim of this study was to investigate surgeons’ reported change of treatment preference in response to the results and conclusion from a randomized controlled trial (RCT) and to study patterns of change between subspecialties and nationalities. Two questionnaires were developed through the Delphi process for this cross-sectional survey of surgical preference. The first questionnaire was sent out before the publication of a RCT and the second questionnaire was sent out after publication. The RCT investigated repair or non-repair of the pronator quadratus (PQ) muscle during volar locked plating of distal radial fractures (DRFs). Overall, 380 orthopaedic surgeons were invited to participate in the first questionnaire, of whom 115 replied. One hundred surgeons were invited to participate in the second questionnaire. The primary outcome was the proportion of surgeons for whom a treatment change was warranted, who then reported a change of treatment preference following the RCT. Secondary outcomes included the reasons for repair or non-repair, reasons for and against following the RCT results, and difference of preferred treatment of the PQ muscle between surgeons of different nationalities, qualifications, years of training, and number of procedures performed per year. Of the 100 surgeons invited for the second questionnaire, 74 replied. For the primary outcome, 6 of 32 surgeons (19%), who usually repaired the PQ muscle and therefore a change of treatment preference was warranted, reported a change of treatment preference based on the RCT publication. Of the secondary outcomes, restoring anatomy was the most common response for repairing the PQ muscle. The majority of the orthopaedic surgeons, where a change of treatment preference was warranted based on the results and conclusion of a RCT, did not report willingness to change their treatment preference

Introduction. Intra articular distal tibia fractures can lead to post-traumatic osteoarthritis. Joint distraction has shown promise in elective cases. However, its application in acute fractures remains unexplored. This pilot study aims to fill this knowledge gap by investigating the benefits of joint distraction in acute fractures. Materials & Methods. We undertook a restrospective cohort study comprising patients with intra-articular distal tibia and pilon fractures treated with a circular ring fixator (CRF) at a single center. Prospective data collection included radiological assessments, Patient-Reported Outcome Measures (PROM), necessity for additional procedures, and Kellgren and Lawrence grade (KL) for osteoarthritis (OA). 137 patients were included in the study, 30 in the distraction group and 107 in the non-distraction group. There was no significant difference between the groups. Results. Mean follow-up was 3.73 years. There was no significant difference between the groups in overall complications or need for further procedures. There was no significant difference in progression of KL between the groups (1.81 vs 2.0, p=0.38) mean follow up 1.90 years. PROM data was available for 44 patients (6 distraction, 38 non-distraction) with a mean follow-up of 1.71 years. There was no significant difference in EQ5D (p=0.32) and C Olerud-H Molander scores (p=0.17). Conclusions. This pilot study suggests that joint distraction is safe in the acute setting. However, the study's impact is constrained by a relatively small patient cohort and a short-term follow-up period. Future investigations should prioritise longer-term follow-ups and involve a larger patient population to more comprehensively evaluate the potential benefits of joint distraction in acute fractures

Introduction. Traditionally, radiological union of fractures treated with an Ilizarov frame is confirmed by a period of dynamization - destabilisation of the frame for a period prior to removal. Reduced clinic availability during the COVID-19 pandemic caused a shift to selective dynamisation in our department, whereby lower risk patients had their frames removed on the same day as destabilisation. This study investigates the effects of this change in practice on outcomes and complication rates. Materials & Methods. Adult patients treated with circular frames between April 2020 and February 2022 were identified from our Ilizarov database. Patients were divided into 2 groups: - “dynamised” if their frame was destabilised for a period to confirm union prior to removal; or “not dynamised” if the decision was taken to remove the frame without a period of dynamisation, other than a short period in the clinic. A retrospective review of clinical notes was conducted to determine outcome. Results. 175 patients were included in the final analysis, 70 in the dynamised and 103 in the not dynamised groups, median follow-up was 33 months. 3 patients in the dynamised group failed dynamisation and had their period of fixation extended, subsequently having their frames removed without complication. Two patients suffered a refracture or non-union after frame removal in the dynamised group and none in the not dynamised group, this difference was not statistically significant. Conclusions. In our practice, selective frame removal without a period of dynamisation appears safe. This has the potential to shorten frame time and reduce the number of clinic appointments and radiographic investigations for these patients. Some patients find the period of dynamisation uncomfortable and associated with pin site infection, which can be avoided. We plan to continue this practice and collect further data to confirm these findings in a larger dataset

This study investigated concurrent talar dome injuries associated with tibial pilon fractures, mapping their distribution across the proximal talar dome articular surface. It compared the two main mechanisms of injury (MOI), falling from a height and motor vehicle accident (MVA), and whether the fractures were open or closed. From a previously compiled database of acute distal tibial pilon fractures (AO/OTA 43B/C) in adults of 105 cases, 53 cases were identified with a concurrent injury to the talar dome with a known mechanism of injury and in 44 it was known if the fracture was open or closed. Case specific 2D injury maps were created using a 1x1mm grid, which were overlayed in an Excel document to allow for comparative analyses. A two-way ANOVA was conducted that examined the effect of both MOI and if the fracture was open or closed on what percentage of the talar dome surface was injured. There was a statistically-significant difference between the average percentage of injured squares on the talar dome by both whether the fracture was open or closed (f(1)=5.27, p= .027) and the mechanism of injury (f(1)=8.08, p= .007), though the interaction between these was not significant (p= .156). Open injuries and injuries that occurred during an MVA were more likely to increase the surface area of the talar dome injuries. We have identified both MOI and if the fracture was either open or closed impacts the size of the injury present on the talar dome. Future research will investigate the aetiology of the differences noted, highlighting the clinical implications. Surgeons treating tibial pilon fractures caused by either a MVA or an open fracture, should be aware of an increased risk of large injuries to the surface of the talar dome

Introduction. Knee arthrodesis is a useful limb salvage technique to maintain function in patients with complex and infected total knee arthroplasties (TKA). There are a number of commonly used external fixators, but no consensus on which of these are optimal. The aim of this study was to synthesise the current literature to guide clinical decision making and improve patient outcomes. We systematically review the literature to compare outcomes of external fixators in arthrodesis following infected TKA. Materials & Methods. A systematic review of the literature of primary research articles investigating the use of external fixators for knee arthrodesis after an infected TKA was conducted. Relevant articles were identified with a search strategy on online databases (EMBASE and Medline) and reviewed by two independent reviewers. Clinical outcome measures were independently extracted by two reviewers which included union rate, infection eradication rate, complication rate, time to fusion, and time in frame. Results. Circular frames were more likely to result in union compared to biplanar (OR 1.40 p=0.456) and monoplanar frames (OR 2.28 p=0.018). Infection recurrence was least likely in those treated by circular frames when compared to monoplanar (OR 0.12 p=0.005) and biplanar external fixators (0.41 P=0.331). Complication rates were highest in the circular fixator group, followed by the monoplanar fixator group and biplanar fixator group at 34%, 31% and 11% respectively. Conclusions. Analysis of the available literature suggests higher union and infection eradication rates with circular frames over the other two fixation methods despite a higher complication rate. There is a paucity in the literature and therefore, no firm conclusions can be drawn. Further research investigating the variations and biomechanical properties between different external fixation methods for knee arthrodesis is necessary. Further clarity in reporting and pooled data would be useful for future analysis

Iliopsoas tendonitis occurs in up to 30% of patients after hip resurfacing arthroplasty (HRA) and is a common reason for revision. The primary purpose of this study was to validate our novel computational model for quantifying iliopsoas impingement in HRA patients using a case-controlled investigation. Secondary purpose was to compare these results with previously measured THA patients. We conducted a retrospective search in an experienced surgeon's database for HRA patients with iliopsoas tendonitis, confirmed via the active hip flexion test in supine, and control patients without iliopsoas tendonitis, resulting in two cohorts of 12 patients. The CT scans were segmented, landmarked, and used to simulate the iliopsoas impingement in supine and standing pelvic positions. Three discrete impingement values were output for each pelvic position, and the mean and maximum of these values were reported. Cup prominence was measured using a novel, nearest-neighbour algorithm. The mean cup prominence for the symptomatic cohort was 10.7mm and 5.1mm for the asymptomatic cohort (p << 0.01). The average standing mean impingement for the symptomatic cohort was 0.1mm and 0.0mm for the asymptomatic cohort (p << 0.01). The average standing maximum impingement for the symptomatic cohort was 0.2mm and 0.0mm for the asymptomatic cohort (p << 0.01). Impingement significantly predicted the probability of pain in logistic regression models and the simulation had a sensitivity of 92%, specificity of 91%, and an AUC ROC curve of 0.95. Using a case-controlled investigation, we demonstrated that our novel simulation could detect iliopsoas impingement and differentiate between the symptomatic and asymptomatic cohorts. Interestingly, the HRA patients demonstrated less impingement than the THA patients, despite greater cup prominence. In conclusion, this tool has the potential to be used preoperatively, to guide decisions about optimal cup placement, and postoperatively, to assist in the diagnosis of iliopsoas tendonitis

Multiple studies have established an inverse relationship between ambient theatre temperatures and polymethyl methacrylate (PMMA) cement setting times. It is also known that allowing cement to equilibrate to ambient theatre temperatures restores expected setting characteristics. One overlooked entity is the transport and storage conditions of cement. This is important in tropical regions, where extreme temperature and humidity may cause rapid cement setting times, resulting in potentially significant intra-operative complications. This study investigated the relationship between extreme transport and storage conditions of Antibiotic Simplex cement (Stryker), and the effect on setting times at Cairns Hospital, Far North Queensland, Australia. Fifty units of cement were divided evenly into a control arm and four experimental arms. The experimental arms were designed to mimic potential transport and storage conditions. They included seven days of storage in a medication fridge, on the hospital loading dock, in a cane shed, and in a Toyota Landcruiser parked outdoors during January 2022. Humidity and temperature readings were recorded. The samples in each group were evenly distributed to equilibrate to theatre conditions for 1 hour and 24 hours. Setting time was recorded when a no. 15 scalpel blade was unable to mark the surface. All three ‘hot’ exposures setting times were significantly faster for both 1 hour (ρ=0.001) and 24 hours (ρ=0.024) equilibration times. The difference in setting times for the ‘cold’ exposure was not significant for either equilibration times (ρ=1). To our knowledge, this is the first study investigating cement setting times in tropical climates. Further studies are required to address the effect of these conditions on biomechanical strength of PMMA cement. We conclude that extreme heat and humidity during transport and storage have a statistically significant effect on cement setting times