Which factors are associated with a successful outcome following total hip arthroplasty in patients with early radiographic osteoarthritis?

BACKGROUND: It is unclear which factors are associated with a successful total hip arthroplasty (THA) in patients with early radiographic osteoarthritis (OA). METHODS: 70 patients with early OA (Kellgren and Lawrence [KL] grades 0-2) who underwent THA were compared with 200 patients with advanced OA (KL grades 3-4). Outcomes were Oxford Hip Scores (OHS), EQ-5D and EQ-VAS scores; compared preoperatively with 1 year postoperatively. We investigated which clinical and radiographic (plain x-ray, CT, MRI) features predicted successful THA (postoperative OHS ⩾42). RESULTS: The early OA group were significantly younger (61 vs. 66 years; [p = 0.0035). There were no significant differences in BMI, ASA grade or gender. After adjusting for confounders, the advanced OA group had a significantly greater percentage of possible change (PoPC) in OHS (75.8% vs. 50.4%; p < 0.0001) and improvement in EQ-5D (0.151 vs. 0.002; p < 0.0001). There were no significant differences in complication, revision or readmission rates. In the early OA group, 16/70 (22.9%) patients had a 'successful' THA. Patients who had a 'successful' THA were significantly more likely to have subchondral cysts on CT/MRI (91.7% vs. 57.7%; p = 0.0362). The presence of cysts on CT/MRI was associated with a significantly greater PoPC in OHS (61.6% vs. 38.2%; p = 0.0353). The combination of cysts and joint space width <1 mm was associated with a PoPC of 68%. CONCLUSIONS: THA in patients with early OA (KL grades 0-2) on plain radiographs should be indicated with caution. We advocate preoperative cross-sectional imaging in these patients. In the absence of cysts on CT/MRI, a THA seems unlikely to provide a satisfactory outcome.

International Delphi Study on Wound Closure and Incision Management in Joint Arthroplasty Part 2: Total Hip Arthroplasty.

BACKGROUND: This modified Delphi study aimed to develop a consensus on optimal wound closure and incision management strategies for total hip arthroplasty (THA). Given the critical nature of wound care and incision management in influencing patient outcomes, this study sought to synthesize evidence-based best practices for wound care in THA procedures. METHODS: An international panel of 20 orthopedic surgeons from Europe, Canada, and the United States evaluated a targeted literature review of 18 statements (14 specific to THA and 4 related to both THA and total knee arthroplasty). There were 3 rounds of anonymous voting per topic using a modified 5-point Likert scale with a predetermined consensus threshold of ≥ 75% agreement necessary for a statement to be accepted. RESULTS: After 3 rounds of voting, consensus was achieved for all 18 statements. Notable recommendations for THA wound management included (1) the use of barbed sutures over non-barbed sutures (shorter closing times and overall cost savings); (2) the use of subcuticular sutures over skin staples (lower risk of superficial infections and higher patient preferences, but longer closing times); (3) the use of mesh-adhesives over silver-impregnated dressings (lower rate of wound complications); (4) for at-risk patients, the use of negative pressure wound therapy over other dressings (lower wound complications and reoperations, as well as fewer dressing changes); and (5) the use of triclosan-coated sutures (lower risk of surgical site infection) over standard sutures. CONCLUSIONS: Through a structured modified Delphi approach, a panel of 20 orthopedic surgeons reached consensus on all 18 statements pertaining to wound closure and incision management in THA. This study provides a foundational framework for establishing evidence-based best practices, aiming to reduce variability in patient outcomes and to enhance the overall quality of care in THA procedures.

International Delphi Study on Wound Closure and Dressing Management in Joint Arthroplasty: Part 1: Total Knee Arthroplasty.

BACKGROUND: The purpose of this modified Delphi study was to obtain consensus on wound closure and dressing management in total knee arthroplasty (TKA). METHODS: The Delphi panel included 20 orthopaedic surgeons from Europe and North America. There were 26 statements identified using a targeted literature review. Consensus was developed for the statements with up to three rounds of anonymous voting per topic. Panelists ranked their agreement with each statement on a five-point Likert scale. An a priori threshold of ≥ 75% was required for consensus. RESULTS: All 26 statements achieved consensus after three rounds of anonymous voting. Wound closure-related interventions that were recommended for use in TKA included: 1) closing in semi-flexion versus extension (superior range of motion); 2) using aspirin for venous thromboembolism prophylaxis over other agents (reduces wound complications); 3) barbed sutures over non-barbed sutures (lower wound complications, better cosmetic appearances, shorter closing times, and overall cost savings); 4) mesh-adhesives over other skin closure methods (lower wound complications, higher patient satisfaction scores, lower rates of readmission); 5) silver-impregnated dressings over standard dressings (lower wound complications, decreased infections, fewer dressing changes); 6) in high-risk patients, negative pressure wound therapy over other dressings (lower wound complications, decreased reoperations, fewer dressing changes); and 7) using triclosan-coated over non-antimicrobial-coated sutures (lower risks of surgical site infection). CONCLUSIONS: Using a modified Delphi approach, the panel achieved consensus on 26 statements pertaining to wound closure and dressing management in TKA. This study forms the basis for identifying critical evidence supported by clinical practice for wound management to help reduce variability, advance standardization, and ultimately improve outcomes during TKA. The results presented here can serve as the foundation for knowledge, education, and improved clinical outcomes for surgeons performing TKAs.

Effect of Various Ancillary Operating Room Techniques on Wound Healing Outcomes After Total Knee Arthroplasty.

INTRODUCTION: The successful management of wound healing after total knee arthroplasty (TKA) depends on several aspects of ancillary intraoperative techniques and surgical variables. Many of these have been evaluated in a few recent reports. The prior reviews studied many aspects of wound healing and, for example, found lower risks of wound complications with barbed sutures compared with interrupted closure with non-barbed sutures, no differences in wound complications between adhesives, subcuticular sutures, staples, glue, or mesh adhesives for the closure of the skin layer, and that mesh adhesives may be associated with faster closing times compared to subcuticular sutures or staples in TKA. However, some topics that can be influenced by the surgeon were not covered in these previous reviews. Namely, the use of deep vein thrombosis (DVT) prophylaxis, tourniquet application, management of intraoperative drains, surgical approach selection, and patellar handling techniques can all potentially influence wound healing. Therefore, in this comprehensive systematic review of the literature, we focused on these five factors that may influence wound healing. Specifically, we evaluated: (1) the impact of different DVT prophylaxis methods on wound healing and infection rates; (2) the role of tourniquet application on wound closure and potential infection risks; (3) the effects of intraoperative drain usage on wound healing; (4) the influence of different surgical approaches on wound closure and postoperative infection rates; and (5) the effects of varying patellar handling strategies on wound healing and infection rates. MATERIALS AND METHODS: A systematic search of electronic databases, including PubMed, Cochrane Library, Medline, and Embase, was conducted to identify studies assessing auxiliary surgical techniques and their impact on wound healing in total knee arthroplasty (TKA). Relevant terms like "knee," "arthroplasty," and "wound healing" refined the search, which included English language publications until May 1, 2023. Independent screening by two authors and a third mediator facilitated the selection process, with 24 studies meeting the criteria. Assessment of these studies involved evaluating their evidence level and methodological quality using the Modified Coleman Methodology Score (MCMS). A comparison was made on wound healing outcomes in TKA, which included evaluating methodological quality parameters like sample sizes, follow-up durations, and clinical effect measurements. Data synthesis for the studies provided a comprehensive summary, categorizing them by evidence level. RESULTS: There were seven reports on DVT prophylaxis that showed no statistically significant differences in wound complications among various treatment methods and medications in patients undergoing total knee arthroplasty (TKA), with wound complication rates ranging from 0.25 to 1%, except that aspirin appeared to have lower wound complications rates in three recent studies than other methods. There were five reports on tourniquet application that showed a generally increased rate of wound complications, but no increase in deep infections. The five reports on intraoperative drain use showed that while there is an increase in total blood loss in the group with drains, ranging from 568ml to 1,856ml, compared to 119ml to 535ml in the no-drain group, there are no significant differences in wound complications, infection rates, or other postoperative outcomes such as swelling, deep vein thrombosis, and range of motion between the drain and no-drain groups. There were three studies on surgical approaches revealing no differences in wound complication rates between the mini-subvastus and medial parapatellar incisions. Also, the surgical variables of patella eversion and anterior tibial translation were only studied in one report. CONCLUSION: The current literature highlights the importance of using aspirin when possible for DVT prophylaxis and the possibility that tourniquets may lead to increased superficial wound complications. Drains or surgical approach do not appear to lead to wound problems. Surgical variables, such as patella eversion and anterior tibial translation, need more study.

Consultant revision hip arthroplasty volumes and new consultant volume trajectories in England, Wales, Northern Ireland, and the Isle of Man.

Aims: This study describes the variation in the annual volumes of revision hip arthroplasty (RHA) undertaken by consultant surgeons nationally, and the rate of accrual of RHA and corresponding primary hip arthroplasty (PHA) volume for new consultants entering practice. Methods: National Joint Registry (NJR) data for England, Wales, Northern Ireland, and the Isle of Man were received for 84,816 RHAs and 818,979 PHAs recorded between April 2011 and December 2019. RHA data comprised all revision procedures, including first-time revisions of PHA and any subsequent re-revisions recorded in public and private healthcare organizations. Annual procedure volumes undertaken by the responsible consultant surgeon in the 12 months prior to every index procedure were determined. We identified a cohort of 'new' HA consultants who commenced practice from 2012 and describe their rate of accrual of PHA and RHA experience. Results: The median annual consultant RHA volume, averaged across all cases, was 21 (interquartile range (IQR) 11 to 34; range 0 to 181). Of 1,695 consultants submitting RHA cases within the study period, the top 20% of surgeons by annual volume performed 74.2% of total RHA case volume. More than half of all consultants who had ever undertaken a RHA maintained an annual volume of just one or fewer RHA, however, collectively contributed less than 3% of the total RHA case volume. Consultant PHA and RHA volumes were positively correlated. Lower-volume surgeons were more likely to undertake RHA for urgent indications (such as infection) as a proportion of their practice, and to do so on weekends and public holidays. Conclusion: The majority of RHAs were undertaken by higher-volume surgeons. There was considerable variation in RHA volumes by indication, day of the week, and between consultants nationally. The rate of accrual of RHA experience by new consultants is low, and has important implications for establishing an experienced RHA consultant workforce.

Is It Safe to Perform Revision Hip Arthroplasty Without Suction Drains?

Background There is a number of studies showing no significant benefit of using drains after primary hip arthroplasty. However, there is no consensus in the literature about the usage of drains in revision hip replacement. This study aims to assess the effect of drains in revision hip arthroplasty. Methods A retrospective analysis was performed of all consecutive revision hip replacement surgeries performed at our unit over a five-month period (November 2018 to March 2019). Case notes, laboratory investigations, and operative records were reviewed. The effects of drains on postoperative hemoglobin (Hb), transfusion rate, and complications were analyzed. Results Overall, 92 patients were analyzed who underwent revision hip replacement during the study period. There were 46 male and 46 female patients with a mean age of 72 years. Aseptic loosening was the most common indication for the revision (41 patients) followed by instability (21 patients), infection (11 patients), and periprosthetic fractures (eight patients). Seventy-two patients had no drains while suction drains were used in 20 patients. Both groups were similar regarding age, sex, and indications for revision surgery. There was a significantly higher drop in postoperative Hb in patients with drains than those without drains (33 g/L: 27 g/L, p=0.03). There were significantly more blood transfusions in patients with drains as compared to those without drains (15%: 8%, relative risk 1.8, and odds ratio 1.94). There was no difference in both groups with regard to returning to the theater. Discussion Use of suctions drains in revision hip surgery was associated with increased postoperative blood loss and increased requirement for postoperative blood transfusion. Revision hip surgery without routine usage of suction drains did not increase wound complications. Conclusion Revision surgery without routine usage of drains is safe and may decrease postoperative blood loss and the rate of transfusion.

A geometric assessment method for estimating dimensional change of retrieved dual mobility liners for total hip arthroplasty.

Despite their emerging use, the current understanding of the in-vivo functional mechanisms of Dual Mobility (DM) Total Hip Replacements (THRs) is poor, and current characterisation methodologies are not suitable for the unique function and design of these types of devices. Therefore, the aim of this study was to develop a geometric characterisation methodology to estimate dimensional change across the articulating surfaces of retrieved DM polyethylene liners so that their invivo function may be better understood. The method involves the acquisition of three-dimensional coordinate data from the internal and external surfaces of DM liners. The data is processed using a bespoke MATLAB script which approximates the unworn reference geometry of each surface, calculates geometric variance at each point and produces surface deviation heatmaps so that areas of wear and/or deformation may be visualised across the implant. One as-manufactured and five retrieved DM liners were assessed, which demonstrated the efficacy, repeatability and sensitivity of the developed method. This study describes an automated and non-destructive approach for assessing retrieved DM liners of any size and from any manufacturer, which may be used in future research to improve our understanding of their in-vivo function and failure mechanisms.

Exploring pelvis and thigh movement and coordination patterns during walking in patients after total hip arthroplasty.

BACKGROUND: Patients after total hip arthroplasty (THA) have altered hip kinematics compared to healthy controls, specifically hip extension and range of motion are lower. Exploring pelvis-thigh coordination patterns and coordination variability may help to elucidate why differences in hip kinematics are evident in patients following THA. RESEARCH QUESTION: Do sagittal plane hip, pelvis and thigh kinematics, and pelvis-thigh movement coordination and coordination variability differ between patients following THA and healthy controls during walking? METHODS: Sagittal plane hip, pelvis and thigh kinematics were collected using a three-dimensional motion capture system while 10 patients who had undergone THA and 10 controls walked at a self-selected pace. A modified vector coding technique was used to quantify pelvis-thigh coordination and coordination variability patterns. Peak hip, pelvis and thigh kinematics and ranges of motion, and movement coordination and coordination variability patterns were quantified and compared between groups. RESULTS: Patients after THA have significantly (p ≤ .036; g ≥ 0.995) smaller peak hip extension and range of motion, and peak thigh anterior tilt and range of motion compared to controls. Additionally, patients following THA have significantly (p ≤ .037; g ≥ 0.646) more in-phase distally and less anti-phase distally dominated pelvis-thigh movement coordination patterns compared to controls. SIGNIFICANCE: The smaller peak hip extension and range of motion displayed by patients following THA is due to smaller peak anterior tilt of the thigh, which in turn limits thigh range of motion. The lower sagittal plane thigh, and in turn hip, motion used by patients after THA may be due to increases in the in-phase coordination of pelvis-thigh motion patterns, which cause the pelvis and thigh to work as a singular functional unit.

Inertial Tracking System for Monitoring Dual Mobility Hip Implants In Vitro.

Dual mobility (DM) implants are being increasingly used for total hip arthroplasties due to the additional range of motion and joint stability they afford over more traditional implant types. Currently, there are no reported methods for monitoring their motions under realistic operating conditions while in vitro and, therefore, it is challenging to predict how they will function under clinically relevant conditions and what failure modes may exist. This study reports the development, calibration, and validation of a novel inertial tracking system that directly mounts to the mobile liner of DM implants. The tracker was custom built and based on a miniaturized, off-the-shelf inertial measurement unit (IMU) and employed a gradient-decent sensor fusion algorithm for amalgamating nine degree-of-freedom IMU readings into three-axis orientation estimates. Additionally, a novel approach to magnetic interference mitigation using a fixed solenoid and magnetic field simulation was evaluated. The system produced orientation measurements to within 1.0° of the true value under ideal conditions and 3.9° with a negligible drift while in vitro, submerged in lubricant, and without a line of sight.

Revision of double-tapered, titanium, fully hydroxyapatite-coated femoral stems: ease of extraction and subsequent reconstruction.

BACKGROUND: Fully hydroxyapatite coated, double-tapered, titanium stems are the most commonly used uncemented implants in the UK with survivorship reported at 96.3% at 23 years however there is no literature on the consequences of revision. We aimed to explore the reasons for failure, ease of stem extraction, extent of bone loss and complexity of the subsequent reconstruction. METHODS: Between December 2012 and March 2019, 104 cases requiring removal of the Corail® stem (DePuy Synthes, Warsaw, IN, USA) were identified from the National Joint Registry (NJR) and our local revision database. Indication for revision, surgical/reconstruction technique, complications and follow-up data were reviewed. RESULTS: The common reasons for revision were aseptic loosening 45.2%, infection 23.5%, instability 4.8% and peri-prosthetic fracture 12.5%. Removal of the implant without extended trochanteric osteotomy (ETO) was achieved in 94.2% of cases. Of those revised for aseptic loosening 23% were proximal, 38% were proximal/mid stem and 38% all zones. Significant bone loss is not a common feature of the failure of this stem with 95% graded as a Paprosky grade 2 or less. In terms of reconstruction, 69.2% were revised to a primary cemented stem. CONCLUSIONS: In the majority of cases revision can be achieved without an ETO and reconstruction possible using a primary stem as significant bone loss is not a common feature of failure of this stem design. We conclude that this stem is safe to use in younger patients who may outlast any type of primary implant and would inevitably face revision in their lifetime.

Do patients with well-functioning total hip arthroplasty achieve typical sagittal plane hip kinematics? A proof of concept study.

BACKGROUND: Total hip arthroplasty (THA) patients have been shown to not achieve normal sagittal plane hip kinematics. However, previous studies have only conducted group level analysis and as such lack the sensitivity to highlight whether individual patients do achieve normal hip kinematics. As such this study looked to determine whether some patients with well-functioning THA achieve typical sagittal plane hip kinematics. METHODS: Sagittal plane hip kinematics were collected on 11 well-functioning THA patients (Oxford Hip Score = 46 ± 3) and 10 asymptomatic controls using a 3-dimensional motion analysis system during self-paced walking. High-functioning THA patients were identified as those who displayed sagittal plane hip kinematics that were within the variance of the control group on average, and low-functioning patients as those who did not. RESULTS: 5 THA patients were identified as high-functioning, displaying hip kinematics within the variance of the control group. High-functioning THA patients displayed peak hip flexion and extension values more closely aligned to asymptomatic control group than low-functioning patients. However, hip range of motion was comparable between high- and low-functioning total hip arthroplasty patients and reduced compared to controls. CONCLUSION: The presence of high-functioning THA patients who display comparable sagittal plane hip kinematics to controls suggests these patients do achieve normative function and challenges the conclusions of previous group level analysis. Understanding why some patients achieve better function post-operatively will aid pre- and post-operative practices to maximise functional recovery.

A comparison of mortality rates following revision hip arthroplasty for periprosthetic fracture, infection or aseptic loosening.

BACKGROUND: Mortality following revision hip surgery for periprosthetic fracture (PPF) is comparable to neck of femur fractures. Our institution provides a regional "PPF Service". The aim of this study was to determine the time to surgery and mortality rate for PPF, compared to revision for infection or aseptic loosening. METHODS: Revision arthroplasty procedures performed for PPF, infection or aseptic loosening between January 2014 and December 2015 were identified. Comparisons were made between the 3 groups for baseline demographics, admission to higher-level care, length of stay, complications and mortality. RESULTS: There were 37 PPF, 71 infected and 221 aseptic revisions. PPF had a higher proportion of females (65% vs. 39% in infection and 53% in aseptic; p = 0.031) and grade 3 and 4 ASA patients (p = 0.006). Median time to surgery for PPF was 8 days (95% CI, 6-16). Single-stage procedures were performed in 84% of PPF, 42% of infections and 99% of aseptic revisions (p < 0.001). 19% of PPF revisions required HDU admission, 1% in the aseptic group and none in the infection group. Median length of stay was significantly different (PPF 10; infection 14; aseptic 8 days (p < 0.001). The 1-year mortality rate for PPF was 0%, 2.8% for infection and 0.9% in the aseptic group (p = 0.342). CONCLUSIONS: Despite the PPF group having higher ASA grades and more HDU admissions, our 1-year mortality rate was 0% and not significantly different to infection or aseptic loosening. Our low complication and 1-year mortality rate is encouraging and supports the safety of a regional "Periprosthetic Fracture Service".

Hip offset and leg-length restoration in revision hip arthroplasty with a monoblock, hydroxyapatite-coated stem.

AIMS: Restoration of normal hip biomechanics in arthroplasty surgery is important in order to achieve good muscle function and joint stability. METHODS: In this retrospective cohort study, we examined the postoperative radiographs of 131 femoral revision arthroplasty procedures using a monoblock, fully hydroxyapatite (HA)-coated titanium stem. Femoral offset, modified-global offset and leg length were measured of the operated and contralateral hips. RESULTS: Femoral offset was restored to ±10 mm in 108 cases (82%), modified-global offset was restored ±10 mm in 93 cases (71%) and leg length was restored to ±10 mm in 102 cases (81%). There were 4 dislocations with a mean follow-up period of 38 months. CONCLUSIONS: Restoration of hip biomechanics is achievable with a monoblock stem and thus is a viable option in revision hip arthroplasty.

Effect of Various Ancillary Operating Room Techniques on Wound Healing Outcomes After Total Hip Arthroplasty.

INTRODUCTION: The successful management of wound healing following total hip arthroplasty (THA) is multifaceted, relying on various intraoperative techniques and surgical variables. Recent reviews have evaluated many of these factors, including the comparison between mesh-adhesive dressings and other skin closure methods, the closing time of different suture techniques, and the four aspects of closure for THA (deep fascial layer; subdermal layer; intradermal layer). However, previous articles did not cover certain topics that can be directly influenced by the surgeon. Specifically, these include the use of deep vein thrombosis (DVT) prophylaxis, the management of intraoperative drains, and the selection of surgical approaches. Therefore, in this comprehensive systematic review of the literature, we have focused on three factors that may influence wound healing. We evaluated the following: (1) the impact of different DVT prophylaxis methods on wound healing and infection rates; (2) the effects of intraoperative drain use on wound healing; (3) the influence of various surgical approaches on wound closure, and postoperative infection rates. By concentrating on these areas, this review aims to provide a more complete understanding of the factors that contribute to successful wound management after THA. MATERIALS AND METHODS: A systematic search of electronic databases, including PubMed, Cochrane Library, Medline, and Embase, was conducted to identify studies assessing surgical variables and techniques, specifically focusing on DVT prophylaxis, intraoperative drain use, and surgical approaches and their impact on wound healing in THA. Relevant terms like "hip," "arthroplasty," "wound healing," "DVT prophylaxis," and "surgical approaches" refined the search, which included English language publications until May 1, 2023. Independent screening by two authors and a third mediator facilitated the selection process, with 13 studies meeting the criteria. Assessment of these studies involved evaluating their evidence level and methodological quality using the Modified Coleman Methodology Score (MCMS). A comparison was made on wound healing outcomes in THA, specifically focusing on the three factors outlined in the introduction: (1) the impact of different DVT prophylaxis methods on wound healing and infection rates; (2) the effects of intraoperative drain use on wound healing; and (3) the influence of various surgical approaches on wound closure and postoperative infection rates. Data synthesis for the studies provided a comprehensive summary, categorizing them by evidence level, and aimed to contribute to a more complete understanding of the factors that influence successful wound management after THA. RESULTS: In studies examining DVT prophylaxis for total knee arthroplasties (TKA), three reports found that both rivaroxaban and enoxaparin had similar wound infection rates at 0.36%. However, one study segment suggested a slightly higher infection rate for rivaroxaban at 0.71% compared to enoxaparin's 0.49%. Despite this difference, it was not statistically significant (odds ratio [OR] 1.34, 95% confidence interval [CI] 0.46 to 3.86). In recent research, a low dose of aspirin has been observed to yield fewer wound complications when contrasted with other techniques. Five studies on intraoperative drain use revealed mixed outcomes. A total of five studies were identified that evaluated wound complications with drains following THA, comprising two randomized controlled trials (RCTs) and three observational cohort studies, with a combined sample size of 765. Among these, four studies specifically compared the use of closed suction drains to no drains. Half of these studies (two out of four) reported no significant differences in wound complications between the two groups, while the other half presented mixed findings. In surgical approach comparisons by Jin et al., meta-analysis between the direct anterior approach (DAA) and posterolateral approach (PLA) showed no significant difference in complications (OR 0.57, p=0.952). Two studies analyzed bikini incision DAA versus PLA or conventional DAA, indicating comparable outcomes with no significant differences in wound complications between the approaches and no major variations in healing, acute PJI, or dysesthesia when comparing bikini incision DAA to conventional DAA. CONCLUSION: Wound healing post THA is a complex process, influenced by various surgical techniques and intraoperative decisions. This systematic review meticulously examined three critical factors: the role of DVT prophylaxis, the implications of intraoperative drain usage, and the impact of different surgical approaches. Our analysis revealed that rivaroxaban and enoxaparin exhibit similar wound infection rates in THA. The decision to use intraoperative drains in the current literature indicates no definite advantage or disadvantage regarding wound problems with the use of closed-suction drainage in THA. In exploring surgical methodologies, the DAA and the PLA showed comparable complication rates. Yet, specific techniques within the DAA category demonstrated variations in delayed wound healing, particularly among obese patients. These findings emphasize the nuanced role of surgical choices in determining wound healing outcomes. As the field of THA continues to evolve, it becomes important for surgeons to be well-informed, ensuring optimal patient outcomes.

Assessing a 12-month course of oral alendronate for adults with avascular necrosis of the hip: MANTIS RCT with internal pilot.

BACKGROUND: People with avascular necrosis of the hip have very limited treatment options currently available to stop the progression of this disease; this often results in the need for a hip replacement. There is some weak evidence that a class of drugs called bisphosphonates may delay the course of the disease, and this trial was commissioned and set up to provide robust evidence regarding the use of bisphosphonates in adults aged ≥ 18 years with this condition. OBJECTIVES: The aim of the Managing Avascular Necrosis Treatments: an Interventional Study ( MANTIS ) trial was to evaluate the clinical effectiveness and cost-effectiveness of a 12-month course of alendronate in the treatment of avascular necrosis. DESIGN: This was a 66-month, definitive, multisite, two-arm, parallel-group, placebo-controlled, double-blind, randomised controlled trial, with an internal pilot phase. SETTING: Eight secondary care NHS hospitals across the UK. PARTICIPANTS: Planned trial size - 280 adult patients with avascular necrosis. INTERVENTION: Participants in the intervention group received 70 mg of alendronate (an oral bisphosphonate) weekly for 12 months. MAIN OUTCOMES: The main outcomes were Oxford Hip Score at 12 months (short-term outcome) and the time to decision that a hip replacement is required at 36 months (long-term outcome). RESULTS: Twenty-one patients were recruited and randomised to receive either the intervention drug, alendronate, or a placebo-matched tablet. LIMITATIONS: This trial was principally limited by low disease prevalence. Other limitations included the late disease stage at which participants were identified and the rapid progression of the disease. FUTURE WORK: This trial was limited by a low recruitment rate. Avascular necrosis of the hip should be treated as a rare disease. Future trials would need to recruit many more sites and recruit over a longer time period, and, for this reason, a registry may provide a more effective means of collecting data pertaining to this disease. CONCLUSIONS: The MANTIS trial was terminated at the end of the pilot phase, because it did not meet its go/no-go criteria. The main issue was a poor recruitment rate, owing to a lower than expected disease prevalence and difficulties in identifying the condition at a sufficiently early stage. Those patients who were identified and screened either were too advanced in their disease progression or were already taking medication. We would not recommend that a short-term interventional study is conducted on this condition until its prevalence, geographic foci and natural history and better understood. The difficulty of acquiring this understanding is likely to be a barrier in most health-care markets. One means of developing this understanding would be the introduction of a database/registry for patients suffering from avascular necrosis of the hip. TRIAL REGISTRATION: The trial is registered as ISRCTN14015902. FUNDING: This project was funded by the National Institute for Health and Care Research ( NIHR ) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 43. See the NIHR Journals Library website for further project information.

WHAT WAS THE QUESTION?: The Managing Avascular Necrosis Treatments: an Interventional Study ( MANTIS ) trial was designed to compare ways of treating patients with avascular necrosis who are seeking to slow down the deterioration of their condition. Alendronate is a drug routinely available across the NHS in both tablet and injection form, and doctors and scientists believe that it might prevent ongoing hip deterioration and result in fewer patients requiring a total hip replacement. WHAT DID WE DO?: This trial attempted to compare alendronate taken as a tablet with an identical-looking tablet that did not contain any of the drug (a placebo) to find out if alendronate reduced the number of patients requiring a hip replacement and having pain (compared with patients who did not get alendronate). WHAT DID WE FIND?: Patients were willing to participate in the trial but we were able to recruit only a small number to the study. The main reason for this was difficulty in identifying potentially suitable patients and approaching them at the right point in their medical care. This was more challenging than anticipated, particularly because the NHS sites and professionals that patients with this condition seek out are extremely variable in the UK. It was also difficult to locate and identify patients with the condition at an early enough stage, and before they had already started taking the drug. WHAT DOES THIS MEAN?: More information on patients with this rare condition, such as NHS referral pathways, and an understanding of how the condition progresses may help to improve our understanding of this patient group. This information could also help us determine whether or not there is scope to carry out the study in a different way that might enable these patients to be more easily identified.

An in vitro methodology for experimental simulation on the natural hip joint.

Different hip pathologies can cause geometric variation of the acetabulum and femoral head. These variations have been considered as an underlying mechanism that affects the tribology of the natural hip joint and changes the stress distribution on the articular surface, potentially leading to joint degradation. To improve understanding of the damage mechanisms and abnormal mechanics of the hip joint, a reliable in-vitro methodology that represents the in vivo mechanical environment is needed where the position of the joint, the congruency of the bones and the loading and motion conditions are clinically relevant and can be modified in a controlled environment. An in vitro simulation methodology was developed and used to assess the effect of loading on a natural hip joint. Porcine hips were dissected and mounted in a single station hip simulator and tested under different loading scenarios. The loading and motion cycle consisted of a simplified gait cycle and three peak axial loading conditions were assessed (Normal, Overload and Overload Plus). Joints were lubricated with Ringer's solution and tests were conducted for 4 hours. Photographs were taken and compared to characterise cartilage surface and labral tissue pre, during and post simulation. The results showed no evidence of damage to samples tested under normal loading conditions, whereas the samples tested under overload and overload plus conditions exhibited different severities of tears and detachment of the labrum at the antero-superior region. The location and severity of damage was consistent for samples tested under the same conditions; supporting the use of this methodology to investigate further effects of altered loading and motion on natural tissue.

Treatment patterns and clinical and economic burden of hip dislocation following primary total hip arthroplasty in England.

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

Development of the Revision Hip Complexity Classification using a modified Delphi technique.

AIMS: The aim of this modified Delphi process was to create a structured Revision Hip Complexity Classification (RHCC) which can be used as a tool to help direct multidisciplinary team (MDT) discussions of complex cases in local or regional revision networks. METHODS: The RHCC was developed with the help of a steering group and an invitation through the British Hip Society (BHS) to members to apply, forming an expert panel of 35. We ran a mixed-method modified Delphi process (three rounds of questionnaires and one virtual meeting). Round 1 consisted of identifying the factors that govern the decision-making and complexities, with weighting given to factors considered most important by experts. Participants were asked to identify classification systems where relevant. Rounds 2 and 3 focused on grouping each factor into H1, H2, or H3, creating a hierarchy of complexity. This was followed by a virtual meeting in an attempt to achieve consensus on the factors which had not achieved consensus in preceding rounds. RESULTS: The expert group achieved strong consensus in 32 out of 36 factors following the Delphi process. The RHCC used the existing Paprosky (acetabulum and femur), Unified Classification System, and American Society of Anesthesiologists (ASA) classification systems. Patients with ASA grade III/IV are recognized with a qualifier of an asterisk added to the final classification. The classification has good intraobserver and interobserver reliability with Kappa values of 0.88 to 0.92 and 0.77 to 0.85, respectively. CONCLUSION: The RHCC has been developed through a modified Delphi technique. RHCC will provide a framework to allow discussion of complex cases as part of a local or regional hip revision MDT. We believe that adoption of the RHCC will provide a comprehensive and reproducible method to describe each patient's case with regard to surgical complexity, in addition to medical comorbidities that may influence their management. Cite this article: Bone Jt Open 2022;3(5):423-431.