Intra-articular injections of steroid into the hip are used for a variety of reasons in current orthopaedic practice. Recently their safety prior to ipsilateral total hip replacement has been called into question owing to concerns about deep joint infection. We undertook a retrospective analysis of all patients who had undergone local anaesthetic and steroid injections followed by ipsilateral total hip replacement over a five-year period. Members of the surgical team, using a lateral approach to the hip, performed all the injections in the operating theatre using a strict aseptic technique. The mean time between injection and total hip replacement was 18 months (4 to 50). The mean follow-up after hip replacement was 25.8 months (9 to 78), during which time no case of deep joint sepsis was found. In our series, ipsilateral local anaesthetic and steroid injections have not conferred an increased risk of infection in total hip replacement. We believe that the practice of intra-articular local anaesthetic and steroid injections to the hip followed by total hip replacement is safer than previously reported

Polymethylmethacetate (PMMA) is a bone cement used in over 725,000 primary hip arthroplasties in 2018. Cement integrity is affected by external factors, including temperature, mixing technique and moisture uptake, which can influence cement microstructure. Changes in the cement microstructure may ultimately threaten the survivorship of the implant. The introduction of enhanced recovery and various local anaesthetic infiltration techniques have been adopted in an attempt to facilitate early mobilisation and reduce length of stay. Our study aims to investigate if the mechanical properties of PMMA are altered with exposure to Ropivacaine LA. Cements were cured in three separate states (air, serum and serum with LA) and the mechanical properties tested at 24 hours and 28 days. Using Refobacin bone cement provided by ZimmerBIOMET, cylindrical molds (12×6mm) were constructed with a split-mold. The LA used was 2mg/ml Ropivacaine hydrochloride solution. Using pilot data, this study was powered to 80% and a sample size of 10 per group (n=60) was calculated. Cement samples were subjected to compressive loading using a universal testing apparatus (Zwick/Roell). Yield-strength and modulus values were extracted from the respective stress versus strain curves. Significant differences were determined by one-way anova for each time point, and Bonferroni post-hoc testing to determine significance between actual groups. At 24-hours there were no significant differences in strength or modulus between groups. At 28-day strength and modulus increased in all groups. Compared to the air group, both serum and LA groups show a significant decrease in compressive strength. The modulus for the LA group is significantly less stiff compared to the air group. The results suggest that the initial exposure to LA has a significant impact on the physical properties of the PMMA. We propose increased awareness of the potential effects this may have on the longevity and survivorship of cemented implants

Introduction. Operating theatre airflow can be measured using pulsed lasers (particle image velocimetry) but the process is difficult to do in 3D. Cup, vane or hot wire anemometers provide only 2D information. 3D measurements enable better understanding of airflow. Patients/Materials & Methods. We used a Windmaster ultrasound 3D anemometer (Skyview systems), which uses three ultrasound transmitters to measure velocity in XYZ planes, with a sampling rate of 32 Hz. Post processing was done using MATLAB. An operating theatre with an Howorth Exflow canopy was studied. Equipment, including lights, was moved. A 50 cm grid was marked, and measurements were made at intervals up to the ceiling. Door opening was observed within the clean zone and the peripheral zone, next to the door and on the opposite side of the room. Anaesthetic screens were studied during operating. Airflow was visualised initially using video of smoke puffs and subsequently measured using the aeronometer. Results. In the upper part of the ultraclean canopy air velocity was 0.34 m/s with a standard deviation of 0.02 m/s, indicating an almost constant velocity. In the periphery there was more turbulence and horizontal air movement. Door opening had no effect on air movements in the clean zone. In the periphery there was an increase in horizontal airflow when the doors are closed. There is a pattern of upward airflow against an anaesthetic screen. This is unlikely to be caused by warming blankets. If the partial wall of the enclosure is lowered this results in a fast washout of air towards the anaesthetist. Discussion. Traditional anaesthetic screens may interfere with airflow. Door opening is a lesser effect. Conclusion. The 3D anemometer enables detailed mapping of airflow within an ultra clean air operating theatre. The data obtained will enable the construction of more accurate computational fluid dynamic models of operating theatres

We investigated 42 patients who were being considered for primary total hip arthroplasty (THA), but in whom it was uncertain whether the hip was the source of their pain. They were given an injection of local anaesthetic into the joint space. Of 33 patients who gained pain relief from their injection, 32 subsequently had successful THA. The remaining patient has not had surgery. The intra-articular injection of local anaesthetic is thus at least 96% sensitive. Of the nine patients who had no or only minimal pain relief from injection, one has had an unsuccessful THA, three have been successfully treated for other conditions and five have unresolved pain for which no organic basis has been established. We believe that the injection of local anaesthetic into the hip is a reliable test, with low morbidity. In difficult cases it will aid in the clarification of the cause of pain which possibly arises from the hip

Aims. The coronavirus disease (COVID)-19 pandemic forced an unprecedented period of challenge to the NHS in the UK where hip fractures in the elderly population are a major public health concern. There are approximately 76,000 hip fractures in the UK each year which make up a substantial proportion of the trauma workload of an average orthopaedic unit. This study aims to assess the impact of the COVID-19 pandemic on hip fracture care service and the emerging lessons to withstand any future outbreaks. Methods. Data were collected retrospectively on 157 hip fractures admitted from March to May 2019 and 2020. The 2020 group was further subdivided into COVID-positive and COVID-negative. Data including the four-hour target, timing to imaging, hours to operation, anaesthetic and operative details, intraoperative complications, postoperative reviews, COVID status, Key Performance Indicators (KPIs), length of stay, postoperative complications, and the 30-day mortality were compiled from computer records and our local National Hip Fracture Database (NHFD) export data. Results. Hip fractures and inpatient falls significantly increased by 61.7% and 7.2% respectively in the 2020 group. A significant difference was found among the three groups regarding anaesthetic preparation time, anaesthetic time, and recovery time. The mortality rate in the 2020 COVID-positive group (36.8%) was significantly higher than both the 2020 COVID-negative and 2019 groups (11.5% and 11.7% respectively). The hospital stay was significantly higher in the COVID-positive group (mean of 24.21 days (SD 19.29)). Conclusion. COVID-19 has had notable effects on the hip fracture care service: hip fracture rates increased significantly. There were inefficiencies in theatre processes for which we have recommended the use of alternate theatres. COVID-19 infection increased the 30-day mortality and hospital stay in hip fractures. More research needs to be done to reduce this risk. Cite this article: Bone Joint Open 2020;1-9:530–540

We report the impact of implementing a new short-stay hip and knee arthroplasty pathway in a National Health Service (NHS) hospital. This was enacted due to existing concerns with a long length of stay (LOS) and reduced elective operating capacity each winter due to emergency bed pressures. The overnight introduction of this pathway was aimed to reduce LOS, alleviate bed pressures, minimise readmission rates and generate financial savings, all combining to facilitate full elective activity during the winter. We conducted a prospective study at a regional tertiary arthroplasty centre. The new pathway was introduced across the service overnight. It includes rigorous preoperative optimisation, specific anaesthetic protocols and uniform changes in surgical practice to allow a focus on early mobilization and discharge on the day of surgery where possible. Data collection spanned 17 months, including the initial six months post implementation of the short-stay pathway. LOS data was collected for the full period and data was compared pre- and post-implementation of the new pathway. Patient satisfaction and 30-day readmission data were also collected. There was an immediate and significant decrease in median LOS from 4 days pre-implementation to 1 day post-implementation. Patient satisfaction was high, and the 30-day readmission rate was unchanged (5.95%), with no readmissions directly related to decreased inpatient stay. Financial analyses revealed substantial cost savings due to reduced LOS and the elimination of routine post-operative blood tests, estimated at over £1.6m per year. Elective activity over winter was significantly higher (79%) than in the same time period in the previous year. An acute introduction of a carefully planned and coordinated short-stay hip and knee pathway is safe, cost-effective and popular with patients, but also contributes to increased efficiency in the delivery of elective healthcare in the context of increasing demand and financial constraints in the NHS

Electronic Health Records (EHRs) have benefits for hospitals and uptake in the UK is increasing. The National Joint Registry (NJR) monitors implant and surgeon performance and relies on accuracy of data. NJR data are used for identification of potential outliers for both mortality and revision; analyses are adjusted for age, sex, and American Society of Anaesthesiologists score (ASA) and cases with some indications are excluded from analyses. In October 2020, the Royal Devon University Hospitals NHS Foundation Trust “went live” on an EHR, almost eradicating paper from the Trust. This included stopping use of paper NJR forms by creating a bespoke electronic template. We sought to identify discrepancies between operation notes and data input to the NJR in variables that may influence potential outlier analyses. Data input to the NJR from 15/10/2020 to 18/10/2022 for hip procedures were provided by NEC Software Solutions. NJR data were compared to those recorded on operation notes. There were 1067 hip procedures recorded in the NJR (946 primary THRs). Of the primary THRs, discrepancies in indication between NJR and operation note were identified in 139 (15%) cases. Common discrepancies included cases being recorded as osteoarthritis where the true indication was acute trauma (n=63), avascular necrosis (n=14), metastatic cancer/malignancy (n=6) and 21 cases with no recorded indication. We identified 88 cases where the ASA recorded in the NJR differed from the anaesthetic chart. Other inaccuracies were identified including 23 cases missing type of procedure (e.g., primary or revision) and one where revision surgery had been recorded as primary. We identified at least 83 cases that should have been excluded from NJR mortality analyses but were not. Given the low incidence of mortality following primary THR, these cases (with increased risk of death) have the potential to incorrectly identify the hospital as a potential outlier. Discrepancies in ASA may also impact on both revision and mortality outlier calculations. We urge caution to hospitals in the implementation of EHRs and advise regular audit of data sent to the NJR

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. This paper aims to review the evidence for patient-related factors associated with less favourable outcomes following hip arthroscopy. Methods. Literature reporting on preoperative patient-related risk factors and outcomes following hip arthroscopy were systematically identified from a computer-assisted literature search of Pubmed (Medline), Embase, and Cochrane Library using Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and a scoping review. Results. Assessment of these texts yielded 101 final articles involving 90,315 hips for qualitative analysis. The most frequently reported risk factor related to a less favourable outcome after hip arthroscopy was older age and preoperative osteoarthritis of the hip. This was followed by female sex and patients who have low preoperative clinical scores, severe hip dysplasia, altered hip morphology (excess acetabular retroversion or excess femoral anteversion or retroversion), or a large cam deformity. Patients receiving workers’ compensation or with rheumatoid arthritis were also more likely to have a less favourable outcome after hip arthroscopy. There is evidence that obesity, smoking, drinking alcohol, and a history of mental illness may be associated with marginally less favourable outcomes after hip arthroscopy. Athletes (except for ice hockey players) enjoy a more rapid recovery after hip arthroscopy than non-athletes. Finally, patients who have a favourable response to local anaesthetic are more likely to have a favourable outcome after hip arthroscopy. Conclusion. Certain patient-related risk factors are associated with less favourable outcomes following hip arthroscopy. Understanding these risk factors will allow the appropriate surgical indications for hip arthroscopy to be further refined and help patients to comprehend their individual risk profile. Cite this article: Bone Joint J 2020;102-B(7):822–831

Only limited data are available regarding the infiltration of local anaesthetic for total hip arthroplasty (THA), and no studies were performed for THA using the anterior approach. . In this prospective, randomised placebo-controlled study we investigated the effect of both standard and reverse infiltration of local anaesthetic in combination with the anterior approach for THA. The primary endpoint was the mean numeric rating score for pain four hours post-operatively. In addition, we recorded the length of hospital stay, the operating time, the destination of the patient at discharge, the use of pain medication, the occurrence of side effects and pain scores at various times post-operatively. Between November 2012 and January 2014, 75 patients were included in the study. They were randomised into three groups: standard infiltration of local anaesthetic, reversed infiltration of local anaesthetic, and placebo. There was no difference in mean numeric rating score for pain four hours post-operatively (p = 0.87). There were significantly more side effects at one and eight hours post-operatively in the placebo group (p = 0.02; p = 0.03), but this did not influence the mobilisation of the patients. There were no differences in all other outcomes between the groups. We found no clinically relevant effect when the infiltration of local anaesthetic with ropivacaine and epinephrine was used in a multimodal pain protocol for THA using the anterior approach. Cite this article: Bone Joint J 2015; 97-B:734–40

Introduction. Early ambulation after total hip arthroplasty (THA) predicts early discharge. Spinal anesthesia is preferred but can delay ambulation, especially with bupivacaine. Mepivacaine, an intermediate-acting local anesthetic, could enable earlier ambulation than bupivacaine. We hypothesized that patients who received mepivacaine would ambulate earlier than those who received hyperbaric bupivacaine or isobaric bupivacaine for primary THA. Methods. This was a randomized, double-blind controlled trial of patients undergoing primary THA. Patients were randomized 1:1:1 to mepivacaine 52.5 mg, hyperbaric bupivacaine 11.25 mg, or isobaric bupivacaine 12.5 mg for spinal anesthesia. The primary outcome measure was ambulation between 3–3.5 hours. Secondary outcomes included return of motor and sensory function, postoperative pain, opioid consumption, urinary retention, transient neurological symptoms, intraoperative muscle tension, length of stay and 30-day readmissions. A priori power analysis required 44 patients per group. After testing for normality (Shapiro-Wilk test), continuous data were analyzed using analysis of variance (ANOVA) or Kruskal-Wallis, as appropriate, and categorical data were analyzed with chi square. Results. Of 154 patients, 50 received mepivacaine, 53 received hyperbaric bupivacaine, and 51 received isobaric bupivacaine. Patient characteristics were similar among groups. For ambulation at 3–3.5 hours, 35/50 (70.0%) of patients met this endpoint in the mepivacaine group, followed by 20/53 (37.7%) of hyperbaric bupivacaine, and then 9/51 (17.6%) of isobaric bupivacaine (p<0.001). Return of motor function occurred earlier with mepivacaine. Pain and opioid consumption were higher for mepivacaine patients in the early postoperative period only. 23/50 (46.0%) of mepivacaine, 13/53 (24.5%) of hyperbaric bupivacaine, and 11/51 (21.5%) of isobaric bupivacaine patients achieved same-day discharge (p=0.014). Length of stay was shortest in mepivacaine patients. There were no differences in complications. Discussion. Mepivacaine patients ambulated earlier and were more likely to be discharged the same day than both hyperbaric bupivacaine and isobaric bupivacaine patients. Mepivacaine could be beneficial for outpatient THA

Background. Total hip replacement (THR) is clinically and cost-effective. The surgical approach influences outcomes, however there is little generalisable and robust evidence to guide practice. We assessed the effect of surgical approach on THR outcomes. Methods. 723,904 primary THRs captured in the National Joint Registry, linked to hospital inpatient, mortality and patient reported outcome measures (PROMs) data with up to 13.75 years follow-up were analysed. There were seven surgical approach groups: conventional posterior, lateral, anterior and trans-trochanteric groups and minimally invasive posterior, lateral and anterior. Survival methods were used to compare revision rates and 90-day mortality. Groups were compared using Cox proportional hazards and Flexible Parametric Survival Modelling (FPM). Confounders included age at surgery, sex, risk group (indications additional to osteoarthritis), ASA grade, THR fixation, thromboprophylaxis, anaesthetic, body mass index (BMI), and deprivation. PROMs were analysed with regression modelling or non-parametric methods. Results. Unadjusted analysis showed a higher revision risk than the referent conventional posterior for the conventional lateral, minimally invasive lateral, minimally invasive anterior and trans-trochanteric groups. This persisted with all adjusted FPM and adjusted Cox models, except in the Cox model including BMI where the higher revision rate persisted for the conventional lateral approach (hazard ratio (HR)=1.12 [95% CI=1.06,1.17] P<0.001). PROMs demonstrated statistically, but not clinically, significant differences. Self-reported complications were more frequent with the conventional lateral approach and the risk of 90-day mortality was higher (HR=1.15 [CI=1.01–1.30] P=0.029). Conclusions. Lateral approaches for THR are associated with worse outcomes, including more deaths and revisions, than the posterior approach

Introduction. Previous studies have indicated that prolonged surgical time may lead to higher rates of infection following total hip arthroplasty (THA). The purpose of this study was to evaluate the influence of surgical time on 30-day complications following THA and to determine if there was a time interval associated with worse outcomes. Methods. Patients ≥18 years who underwent THA between 2005 and 2016 were identified from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database using procedural codes. Patients with surgical durations >240 minutes were excluded. Patient demographics, operation length, and 30-day major and minor complications were ascertained. Multivariable regression was used to determine if the rate of complications differed depending on length of operation, while adjusting for relevant covariables, and to identify independent predictors of operation length. Covariables of interest included age, sex, American Society of Anaesthesiologists (ASA) class, smoking status, functional status, comorbidities, anesthesia type, and Body Mass Index (BMI). Results. A total of 132,043 THA patients (average age 65 ±12 years) were identified from the database. Of these, 2,177 (1.64%) experienced a major complication, and 3,504 (2.64%) experienced a minor complication within 30-days of the initial procedure. Average operation length was 92.0 minutes (range 20 – 240 minutes). Independent predictors of prolonged operation length included overweight/obese BMI, male sex, cancer, dependent functional status, epidural anaesthetic, and ASA class II, III or IV vs. I Alternatively, older age, current smoking, and spinal anaesthetic were associated with shorter surgical durations. Unadjusted rates of both major and minor complications were significantly higher for patients whose operation lengths were ≥ 120 minutes (P>0.001). Specifically, patients whose operations lasted ≥ 120 minutes had higher rates of septic shock, sepsis, pulmonary embolism (PE), deep vein thrombosis (DVT), urinary tract infection (UTI), renal insufficiency, surgical site infection(SSI) and wound disruption. After covariable adjustment, surgical durations of 90–119 minutes increased the risk of minor complications by 1.2 (95%Confidence interval [95%CI] 1.1–1.3), while surgical durations of 120–180 minutes increased the risk of major complications by 1.4 (95%CI 1.3 – 1.6), and minor complications by 1.4 (95%CI 1.2 – 1.5), and surgical durations ≥180 minutes increased the risk of major complications by 2.1 (95%CI 1.8 – 2.6), and minor complications by 1.9 (95%CI 1.6 – 2.3). There was no difference in the overall risk of complications for operation times lasting 20 – 39, 40 – 59, or 60 – 89 minutes (P>0.05). In terms of specific complications, operation length ≥90 minutes was determined to be an independent risk factor for deep and superficial incisional SSI, as well as wound disruption, while operation length ≥ 120 minutes was an independent risk factor for sepsis, UTI, and deep, non-incisional SSI and operation length ≥ 180 minutes was an independent risk factor for PE, DVT, and cardiac arrest (p<0.05). Conclusion. These data indicate that prolonged surgical durations may be an independent predictor of major and minor complications following THA. This suggests that quality improvements could be made to improve operating room efficiency and surgical times and therefore postoperative outcomes

Introduction. The periacetabular osteotomy (PAO) improves hip joint mechanics in patients with symptomatic dysplasia. As a consequence of the multi-planar acetabular re-orientation, the course of the iliopsoas tendon over the hip may be affected, potentially resulting in iliopsoas tendon-related pain. At present, little information regarding the incidence of iliopsoas-related pathology following PAO exists. We aimed to identify the incidence of iliopsoas-related pain following PAO. Secondarily, we aimed to identify any risk factors associated with this pathology. Methods. We retrospectively reviewed the PAO's performed from 2014–2017, for symptomatic dysplasia in our unit (single-surgeon, minimum 1-year follow-up). All patients with adequate pelvic radiographs were included. Radiographic parameters of dysplasia were measured from pre- and post-operative AP pelvic radiographs using a validated software (SHIPS). 1. The degree of pubis displacement was classified according to our novel system. Cases were defined as those with evidence of iliopsoas-related pain post PAO (positive response to iliopsoas tendon-sheath steroid/local anaesthetic injection). Results. A total of 241 patients were included (mean age 28 years). We identified 23 cases (10.6%) with iliopsoas tendon-related pain post-PAO. Three of these cases required an open iliopsoas tendon release and 1 required a revision of their PAO. This was successful in treating symptoms in all. The remainder required either 1–2 iliopsoas tendon-sheath steroid injections to successfully treat their symptoms. We found no significantly associated risk factors with regard to demographics, severity or type of dysplasia, and degree of pubis displacement. Conclusion. The minimally-invasive PAO remains a successful technique for treating symptomatic dysplasia. Despite this, we report a 10.6% incidence of iliopsoas tendon-related pain following surgery. In the vast majority this is successfully treated with an iliopsoas tendon-sheath steroid injection. The ability to identify and treat patients with this pathology early during their post-operative PAO recovery will enable patients to maximise their rehabilitation outcomes

The unparalleled events of the year 2020 continue to evolve and challenge the worldwide community on a daily basis. The COVID-19 pandemic has had a major impact on all aspects of our lives, and has caused major morbidity and mortality around the globe. The impact of COVID-19 on the practice of orthopedic surgery has been substantial with practice shutdowns, elective surgery restrictions, heightened utilization of telemedicine platforms and implementation of precautionary measures for in-person clinic visits. During this transition period the scholarly and educational pursuits of academic surgeons have been de-emphasized as the more immediate demands of clinical practice survivorship have been the priority. This unavoidable focus on clinical practice has heightened the importance of orthopedic subspecialty societies in maintaining an appropriate level of attention on research and educational activities. Under the outstanding presidential leadership of Robert Barrack, MD, The Hip Society adapted to the profound challenges of 2020, and maintained strong leadership in the realms of education and research. The recent 2020 summer meeting of the Hip Society was a testimonial to the resilience and dedication of the Society members to ongoing innovation in research and education. Due to travel and social distancing restrictions the 2020 summer meeting was transitioned from an in-person to a virtual meeting format. Dr Barrack and Program Chair Dr John Clohisy assisted with oversight of the meeting, while Olga Foley and Cynthia Garcia ensured the success of the meeting with remarkable planning and organization. These collaborative efforts resulted in an organized, well-attended, high level scientific meeting with engaging discussion and a remarkable virtual conference environment. The Bone & Joint Journal is very pleased to partner with The Hip Society to publish the proceedings of this very unique virtual meeting. The Hip Society is based in the United States and membership is granted to select individuals for leadership accomplishments in education and research related to hip disease. The Society is focused on the mission of advancing the knowledge and treatment of hip disorders to improve the lives of patients. The vision of the Hip Society is to lead in the discovery and dissemination of knowledge related to disorders of the hip. The annual closed meeting is one of the most important events of the society as this gathering highlights timely, controversial and novel research contributions from the membership. The top research papers from The Hip Society meeting will be published and made available to the wider orthopedic community in The Bone & Joint Journal. This partnership with The Bone & Joint Journal enhances the mission and vision of The Hip Society by international dissemination of the meeting proceedings. Given the far-reaching circulation of The Bone & Joint Journal the highest quality work is available to an expanding body of surgeons, associated healthcare providers and patients. Ultimately, this facilitates the overarching Hip Society goal of improving the lives of our patients. The 2020 virtual Hip Society meeting was characterized by outstanding member attendance, high quality paper presentations and robust discussion sessions. The meeting was held over two days and encompassed 58 open paper presentations divided into ten sessions with moderated discussions after each session. All papers will be presented in this issue in abstract form, while selected full papers passing our rigorous peer review process will be available online and in The Bone & Joint Journal in a dedicated supplement in 2021. The first session of the meeting focused on issues related to complex primary THA and osteonecrosis of the femoral head. Dr Gross presented on the conversion of hip fusion to THA in 28 patents at a mean 7 years. He reported a high clinical success rate, yet complications of heterotopic ossification and neurologic injury were relatively common. Consideration of heterotopic ossification prophylaxis and the selective use of a constrained liner were recommended. Dr Pagnano summarized the use of various contemporary porous acetabular components in 38 hips in the setting of prior pelvic radiation. The mean follow-up was 5 years and 10 year survivorship was 100% with all implants radiographically fixed. Dr Bolognesi's study demonstrated that THA in solid organ transplant patients is associated with higher risk for facility placement, transfusions and readmissions. This patient population also has increased mortality risk (4.3% risk at 1 year) especially lung transplant patients. The second group of papers focused on femoral head osteonecrosis. Dr Iorio presented single center data demonstrating that CT scan was a useful adjunct for diagnosis in the staging work-up for cancer, yet was not useful for ARCO staging and treatment decision-making. On the basic science side, Dr Goodman utilized a rabbit model of steroid-induced femoral head osteonecrosis to determine that immunomodulation with IL-4 has the potential to improve bone healing after core decompression. The session was concluded by Dr Nelson's study of ceramic-on-ceramic THA in 108 osteonecrosis patients. The median 12 year results were outstanding with marked increases in PROs, maintenance of high activity levels, and a 3.7% revision rate. In the second session attention was directed to THA instability and spinopelvic mobility. Dr Sierra presented a machine learning algorithm for THA dislocation risk. Two modifiable variables (anterior/lateral approach, elevated liner) were most influential in minimizing dislocation risk. Dr Taunton's study demonstrated a deep learning artificial intelligence model derived from postoperative radiographs to predict THA dislocation risk. High sensitivity and negative predictive value suggest that this model may be helpful in assessing postoperative dislocation risk. In reviewing a large single-center, multiple surgeon cohort of 2,831 DAA procedures, Dr Moskal noted a very low dislocation rate (0.45%) at minimum 2 years. Importantly, spinopelvic pathology or prior spinal instrumentation was not associated with an increased dislocation risk (0.30%). Dr Huo and colleagues analyzed pelvic tilt during functional gait in patients with acetabular dysplasia. They detected variable pelvic tilt on different surfaces with the data suggesting that patients with more anterior pelvic tilt while standing tend to have greater compensatory posterior pelvic tilt during gait. Dr Lamontagne reported on the sagittal and axial spinomobility in patients with hip OA, and highlighted reductions in pelvic tilt, pelvic-femoral-angle, lumbar lordosis and seated maximal trunk rotation when compared to controls. Dr Dennis showed that differences in spinopelvic mobility may explain the variable accuracy of acetabular version measurements on the cross-table lateral radiographs. Dr Gwo-Chin presented on a comprehensive functional analysis of 1,592 patients undergoing THA and observed that spinopelvic abnormalities are not infrequent (14%) in THA patients. Consistent with these findings Dr Murphy and collaborators identified a low prevalence of previous spinal instrumentation (1.5%), yet a high prevalence of spine stiffness (27.6%) in 149 patients undergoing THA. Session three highlighted various aspects of treating hip disease in young patients. Dr Peters investigated the need for subsequent hip arthroscopy in 272 patients treated with an isolated PAO. Only 4.8% of these patients required subsequent arthroscopy calling into question the routine use of combined arthroscopy and PAO. Three papers addressed questions related to THA in young patients. Dr Berend's study of 2532 hips demonstrated that high activity level was not associated with an increased risk of midterm aseptic or all cause failure. Dr Nunley presented on 43 young patients with an average age of 52 years treated with a cementless stem and modular dual mobility articulation. Stress shielding was minimal and no concerning metal ion release detected. Dr Garvin summarized minimum 15 year data of THA with highly cross-linked polyethylene in patient less than 50 years. These hips performed exceptionally well with no mechanical loosening or radiographic osteolysis. Dr Engh examined 10 year results of the Birmingham Hip Resurfacing implant and reported a 92.9 % overall survivorship, with males less than 55 years achieving a 98.3% survivorship. The session was concluded by long-term data on the Conserve Plus hip resurfacing arthroplasty. Dr Amstutz presented an impressive dataset depicting an 83.1% 20 year survivorship for this early resurfacing cohort. Direct anterior approach total hip arthroplasty was the focus of session four. Dr Meneghini reported on the anesthesia and surgical times of direct anterior and posterior approaches from a large healthcare system database. These data suggested longer OR and surgical times for the DAA both in the inpatient and ASC environments. Dr Clohisy introduced the technique and early outcomes of lateral decubitus position DAA. In a learning curve experience of 257 hips. 96% of acetabular components were in the Lewinneck safe zone, the aseptic revision rate was 0.9% and there were no dislocations. Dr Beaule analyzed femoral stem cement mantle with the DAA and posterior approaches by comparing two matched cohorts. Stem alignment and cement mantle quality were equivalent with both approaches. Similarly, Dr Emerson demonstrated technical feasibility and fewer cemented femoral stem failures when compared to cementless stems in a series of 360 DAAs THAs. The final paper of the session presented by Dr Hamilton examined the impact of surgical approach on dislocation after isolated head and liner exchange. Neither the posterior nor the anterior approach was superior in reducing the dislocation rate for these high dislocation risk procedures. The fifth session explored contemporary topics related to anesthesia and pain management. Dr Byrd opened the session with a comparative study evaluating general versus spinal anesthesia for hip arthroscopy. This preliminary study was provoked by the desire to minimize aerosolized exposure early in the COVID-19 pandemic by transitioning to spinal anesthesia. Both anesthetic methods were effective. Dr Austin presented a randomized, double-blind controlled trial comparing spinal anesthetic with mepivacaine, hyperbaric bupivacaine and isobaric bupivacaine. Mepivacaine patients ambulated earlier and were more likely to be discharged the same day. Dr Mont provided a very timely study on the effects of “cannabis use disorder” and THA outcomes. This administrative database study of 44,154 patients revealed this disorder to be associated with longer hospital stays, increased complications rates and higher costs. Dr Bedair investigated whether a highly porous acetabular component submerged in an analgesic solution could enhance perioperative pain management. Interestingly, this novel strategy was associated with a reduction of postoperative pain scores and opioid consumption in 100 experimental patients compared to 100 controls. The concluding paper of the session by Dr Della Valle examined whether decreased discharge opioids led to increased postoperative opioid refills. A large single-center study of 19,428 patients detected a slight increase (5%) in opioid refills but a reduction in total refill morphine milligram equivalents. The final, sixth session of day one considered various challenging aspects of revision hip arthroplasty. Dr Nam started the session with review of preliminary results from a randomized control trial comparing closed incision negative-pressure therapy with a silver-impregnated dressing for wound management in 113 hips undergoing revision arthroplasty. Unlike previous reports, the negative pressure therapy was associated with a higher reoperation rate for wound-related complications. Dr Bostrom highlighted the potential clinical impact of basic biological interventions by establishing the presence of Neutrophil Extracellular Traps (NETS) in fibrotic tissue from human aseptic loosening specimens and in a murine model of unstable tibial implantation. NET inhibition in the murine model prevented the expected tibial implant osseointegration failure. Dr Lombardi presented early 3.3 year clinical results of a highly porous Ti6al4v acetabular component in complex primary and revision arthroplasty. Survivorship for aseptic loosening was 96.6 % and 95.3% for the primary and revision cases, respectively. Dr Schwarzkopf and colleagues explored the impact of time to revision arthroplasty on clinical outcomes. Analysis of 188 revision cases revealed early revisions (less than 2 years from primary) were associated with worse outcomes, longer hospitalizations and higher reoperation rates. Mid-term results for modular dual mobility implants in revision arthroplasty were reviewed by Dr Lachiewicz who reported on 126 hips at a mean 5.5 years. 11% of hips dislocated and the 6 year survival was 91%. An outer head diameter of 48mm or greater was associated with a lower risk of dislocation. Dr Berry concluded the session by discussing the outcomes of treating the challenging problem of interprosthetic femur fractures. A single-center study of 77 cases treated over 32 years demonstrated a 79% success rate free of reoperation at 2 years with 95% of patients being ambulatory. The second day commenced with the seventh session evaluating recent strategies to improve short-term THA outcomes. Dr Bozic and colleagues investigated the association of quality measure public reporting with hip/knee replacement outcomes. Annual trend data from 2010–2011 and 2016–2017 indicate that hospital-level complication and readmission rates decease after the start of public reporting, yet it is difficult to prove a direct effect. Dr Slover reviewed his institutions experience with the Comprehensive Care for Joint Replacement (CJR) model and emphasized that lower CJR target prices make it increasingly difficult for programs to meet target price thresholds. Cost saving strategies including same day discharge and reduction of home health services may result in smaller losses of positive margins. Dr Barsoum reported on the influence of patient and procedure-related risk factors of length of stay after THA. Patient-related risk factors provided substantial predictive value yet procedure-related risk factors (hospital site and surgical approach) remain the main drivers of predicting length of stay. Dr Hozack reviewed an impressive, single surgeon cohort of 3,977 DAA THAs and analyzed adverse events and 90 day perioperative outcomes. Simultaneous bilateral DAA THA was comparable with unilateral or staged bilateral procedures in regards to complications, readmission rate and home discharge rate but with an increased risk of transfusion. To examine the risk of complications with outpatient joint arthroplasty, Dr Della Valle performed a single-surgeon matched cohort analysis comparing outpatient and inpatient hip and knee arthroplasties. Outpatient procedures were not associated with an increased risk of any postoperative complications and actually experienced fewer emergency department visits. The eighth session covered various contemporary challenges in hip arthroplasty care. Dr Griffin began the session with an analysis of the timing of complications associated with two-stage exchange procedures for periprosthetic joint infection (PJI). Of the 189 hips included, 41.6% had a complication and the mortality was 14.1% at 2.5 years, highlighting the morbidity of this treatment method. Dr Fehring provided data assessing the fate of two-stage reimplantation after failed debridement, antibiotics and implant retention (DAIR) for a prosthetic hip infection. This analysis of 114 hips yielded concerning results demonstrating a 42.9% treatment failure of patients treated with a previous DAIR compared to a 12.3% failure rate in patients treated with an initial 2-stage procedure. Dr Jacobs reviewed the analysis of 106 femoral heads with severe corrosion and identified a chemically dominated etching process termed “column damage” to be a detrimental damage mode within CoCr femoral heads that is directly linked to banding within its microstructure. These data indicate that implant alloy microstructure must be optimized to minimize the release of fretting-corrosion products. Simon Mears presented retrospective data from 184 THAs with a dual modular femoral stem. A subgroup of hips with a modular, cobalt chromium femoral neck had a pseudotumor visualized in 15% with only 55% of these having elevated CoCr levels. These findings may support the use of routine follow-up MARS MRI for modular CoCr femoral neck prostheses. The final two studies explored timely issues related to viral illness and hip surgery. Dr Browne analyzed three large administrative databases to elucidate whether patients are at increased risk for viral illnesses following total joint replacement. The incidence of postoperative influenza after total joint replacement was not increased compared to patients not undergoing total joint replacement surgery suggesting that arthroplasty procedures may not heighten the risk of viral illness. In the final paper of the session Dr Haddad presented important data regarding perioperative complications in coronavirus positive patients undergoing surgical treatment of femoral neck fractures. In this multicenter cohort study from the United Kingdom 82 coronavirus positive patients were shown to have longer hospital stays, more critical care unit admissions, higher risk of perioperative complications and an increased mortality compared to 340 coronavirus negative patients. The eighth session had two papers on alternative femoral stem designs and three presentations more focused on femoral fracture treatments. Dr Mihalko focused on the European and US experiences with the Metha femoral neck retaining stem. The US experience mirrored the encouraging results from Europe with a 94% all cause femoral survivorship and a 99.1% femoral aseptic loosening survivorship at 5 years. Dr Kraay summarized dual energy x-ray absorptiometry (DEXA) evaluation of 16 low modulus composite femoral components at long-term follow-up of a mean 22 years. The bone mineral density associated with the implant increased in Gruen zones 2–6 and showed limited decreases in zones 1 and 7. These data support the concept that a low modulus femoral stem may more effectively load the proximal femur. Dr Springer provided data from the American Joint Replacement Registry (AJRR) and by evaluating outcomes of exact matched cohorts of 17,138 patients treated with cementless or cemented femoral implants for femoral neck fractures. Cemented implants were associated with marked reduction in early revision and periprosthetic fractures. However, cemented fixation was associated with an increased mortality at 90 days and 1 year. Additional data from the AJRR was presented by Dr Huddleston who investigated the risk factors for revision surgery after arthroplasty in a cohort of 75,333 femoral neck fractures. THA when compared to hemiarthroplasty was associated with higher early and overall revision rates. Cementless femoral fixation and increased age were also associated with higher rates of any revision. Both of these studies from the AJRR suggest that further consideration should be given to femoral fixation preferences in the femoral neck fracture population. Dr Vail summarized his institution's experience with an interdisciplinary hip fracture protocol for patients undergoing arthroplasty for acute femoral neck fractures. His study compared 157 cases prior to protocol implementation with 114 patients treated after the protocol was established. The impact of the interdisciplinary protocol was impressive as evidenced by a reduced time to operative treatment, length of stay, complication rate and one-year mortality. All being achieved without an increase in readmissions or facility discharges. The final session of the meeting addressed innovations in perioperative care of THA patients. Dr Barrack started the session with an interesting study examining the feasibility and patient preferences regarding telemedicine. A cross-sectional telephone survey of 163 arthroplasty patients indicated that 88% of patients use the internet and 94% own a device capable of videoconferencing. Nevertheless, only 18% of patients preferred a video visit over an in-person clinic visit due to concerns of inferior care. Dr Barnes quantified preoperative optimization work in 100 arthroplasty patients by using EMR activity logs and determined the surgical team spends an average 75 minutes per case on preoperative work activities. Dr Duwelius reported the early outcomes of primary THA with a smartphone-based exercise and educational platform compared to standard of care controls. A randomized control trial design with 365 patients demonstrated similar outcomes and non-inferiority of the smartphone platform relative to complications, readmissions, emergency room/urgent care visits. The association of controlled substance use with THA outcomes was assessed by Dr Higuera Rueda. A quantitative assessment using the NarxCare score identified 300 and above as a score associated with adverse outcomes after THA. Dr Macaulay reviewed data from a large retrospective study of 1,825 THAs indicating that discontinuation of intermittent pneumatic compression devices does not increase the risk of venous thromboembolism in standard risk patients being treated with 81mg ASA BID as prophylaxis. Dr Antoniou presented the final paper of the meeting investigating potential changes in patient health status as an indication for surgery over time. Data from this large systematic review of the literature found patients undergoing THA at similar health status to the past with no influence form patient age, gender, year of enrollment or geographic region. As summarized above, the 2020 virtual Hip Society Summer Meeting was rich in scientific content, productive discussion and a collaborative spirit. This collective body of work will result in impactful scientific contributions and will serve as a foundation for future innovation and advancements in the treatment of hip disease

Background. This clinical study aims to establish the rate of operative inadvertent hypothermia (IH) in elderly hip fracture patients (>65 years old). We postulate that differences exist in risk factors and hypothesised poorer outcomes in patients with IH. Methods. A single centre, retrospective study of 929 hip fracture patients managed operatively between June 2015 and July 2017 was conducted. Patients’ demographic, anaesthetic and surgical variables were analysed together with outcomes for length of stay (LOS), 30-day re-admissions, and 30-day mortality. Results. Overall rates of IH in elderly hip fracture patients undergoing surgery were 10%, with increasing age as a risk factor (p = 0.005). There was trend towards IH in patients receiving sliding hip screw (SHS) (p = 0.079). No difference in LOS was observed between IH and normothermic patients (8.9 ± 7.1 versus 8.6 ± 4.9, p= 0.51). 30-day re-admissions were 18.5% for IH patients versus 7.8% in normothermic patients (p<0.001). There was a trend towards a higher 30-day mortality (p = 0.089), and a significantly higher mortality in IH patients undergoing SHS (p = 0.014). Conclusion. Rates of IH are high in operatively managed hip fracture patients. IH is significantly associated with a higher 30-day readmission rate with a trend towards higher 30-day mortality. This study mandates an examination of strategies for maintaining normothermia in operatively managed elderly hip fracture patients

With the increasing demand for hip and knee replacement and move towards seven-day services, we examined whether this planned, elective surgery performed at the weekend is associated with a different 30-day mortality versus that performed between Monday and Friday. The study dataset comprised 118,096 joint replacement episodes performed at the weekend and 1,233,882 episodes done on a weekday. We used a Kaplan-Meier framework to examine the 30-day cumulative mortality rate for all elective hip and knee replacements performed in England and Wales and recorded in the NJR between 1st April 2003 and 31st December 2014, with Cox proportional-hazards regression models to assess for time-dependent variation and adjust for identified risk factors for mortality. For hip replacement the cumulative 30-day mortality was 0.15% (95%CI: 0.12–0.19) for patients operated on at the weekend versus 0.20% (0.19–0.21) for patients undergoing surgery during the normal working week. For knee replacement the cumulative 30-day mortality was 0.14% (0.11–0.17) for patients operated on at the weekend versus 0.18% (0.17–0.19) for patients undergoing surgery during the normal working week. The lower mortality associated with weekend operating was most apparent in the later years of the audit (2009 to 2014) and remained after adjustment for any differences in patient age, gender, American Society of Anaesthesiologist grade, surgeon seniority, surgical and anaesthetic practices, and thrombo-prophylaxis choice in weekend versus weekday operated patients. Routine hip and knee replacements performed at the weekend in England and Wales and are not associated with an increased risk of post-operative mortality

Introduction. Heterotopic Ossification(HO) is a recognized complication following Total Hip Arthroplasty(THA) that can compromise patient outcomes. Our objectives were to report its incidence and risk factors in a modern arthroplasty unit(MAU). Methods. 2305 consecutive primary THAs in 2150 patients(887♂;1263♀) undertaken at a single centre and followed-up for at least one year constituted the study cohort. A retrospective review of patient demographics (age, side, body mass index[BMI], type of anaesthesia, surgical approach, method of fixation, estimated blood loss[EBL] and operative time), serial radiographs and outcome measure (The Oxford hip score[OHS]) were undertaken. All HO were further followed for additional four years to determine the incidence of Revision THA at five years. Descriptive statistics and logistic regression was undertaken to identify the risk factors for HO using Statistical Package(SPSS) version16. Results. The mean age and BMI were 67.9±SD9.9years and 29.7±SD5.5 respectively. The mean operative time and blood loss was 72±SD18minutes. 148 hips in 146 patients(83♂;63♀) had established HO in 6.79% patients(146/2150). The first year incidence of HO was 6.42%(148/2305) and the incidence of severe HO (Brooker's Grade III+IV) was 1.47%(34/2305). We did not find any difference in the incidence of HO for choice of fixation (Cemented[6.9%]; Uncemented[6.7%]; Hybrid[5.6%]). The mean OHS was 42±SD7 and overall satisfaction at one year was 97.5%. There was no difference in OHS between the two groups(p=0.39). Statistically significant risk factors (p=0.0001) on logistical regression were male gender (Odds Ratio[OR]=1.97;95%CI:1.40–2.76) and anterolateral (OR=2.05;95%CI:1.42–2.95) approach. Excision of HO mass and Revision THA was undertaken in two instances by five years. Discussion. Incidence of HO in MAU is lower than previous published literature (10–47%). Uncemented THA. EBL and epidural anaesthetic were not found to be associated with higher incidence of HO as previously reported in the literature. The incidence of Revision THA in HO patients was 1.35% at 5 years

The purpose of this study was to determine the complications after Bernese periacetabular osteomy (PAO) performed by one experienced surgeon using a minimally invasive modified Smith-Petersen approach. Between May 2012 and December 2015, 224 periacetabular osteotomies (PAO) in 201 patients were performed. The perioperative complications were retrospectively reviewed after reviewing clinical notes and radiographs. The mean age was 28.8 years with 179 females and 22 males. The most common diagnosis was acetabular dysplasia with some cases of retroversion. The average lateral centre edge (LCE) angle was 16.5°(−18–45) and mean acetabular index (AI) 16.79° (−3–50). Postoperatively the mean LCE angle was 33.1°(20–51.3) and mean AI 3.0°. (−13.5–16.6). There were no deep infections, no major nerve or vascular injuries and only one allogenic blood transfusion. Nine superficial wound infections required oral antibiotics and two wounds needed a surgical debridement. There was one pulmonary embolus and one deep vein thrombosis. Nine (4%) cases underwent a subsequent hip arthroscopy and three (1.3%) PAO's were converted to a total hip arthroplasty after a mean follow-up of 22 months (3–50). Lateral femoral cutaneous nerve dysaesthesia was noted in 64 (28.6%) PAO's. In 55 (24.5%) an iliopsoas injection of local anaesthetic and steroid for persistent iliopsoas irritation during the recovery phase was given. The minimally invasive modified Smith-Petersen approach is suitable to perform a Bernese periacetabular osteotomy with a low perioperative complication rate. Persistent pain related to iliopsoas is a not uncommon finding and perhaps under-reported in the literature

Tissue sparing hip replacements have recently gained popularity, in an attempt to provide shorter hospital stay, faster recovery time and potentially to reduce morbidity and complications. Direct anterior approaches (DAA) have been shown to allow faster recovery, but also appear to be associated with a higher incidence of complications, especially during the learning curve. Mini-posterior approaches have the advantage of increased familiarity, however may not be maximally muscle sparing. Prospective and retrospective data was collected following a published protocol. This included patient demographic data, theatre time, units of blood transfused, length of stay, functional scores and radiological parameters. Rates of conversion to posterior approach and complications were also documented. The results of our first 100 cases completed are presented: Within this initial cohort, three patients suffered major complications: These included an anterior dislocation, which was successfully reduced with closed reduction under general anaesthetic, an early (day 6) periprosthetic fracture, which was successfully revised to a cemented prosthesis, and a case of stem subsidence. Our results also suggest a learning curve effect, limited to theatre time and blood loss. Complications were evenly distributed throughout the period of study and are of similar frequency to standard approaches. As the first European centre to adopt the SuperPATH approach, we have shown that the published results from America can be reproduced. In contrast to DAA, the learning curve is not associated with higher rates of femoral fracture and other complications. The fact that the approach is extensile, being the superior part of the posterior approach, allows for all of the advantages of muscle preservation with the safety of potential extension when necessary