Aims. Osteoarthritis (OA) is a prevalent joint disorder with inflammatory response and cartilage deterioration as its main features. Dihydrocaffeic acid (DHCA), a bioactive component extracted from natural plant (gynura bicolor), has demonstrated anti-inflammatory properties in various diseases. We aimed to explore the chondroprotective effect of DHCA on OA and its potential mechanism. Methods. In vitro, interleukin-1 beta (IL-1β) was used to establish the mice OA chondrocytes. Cell counting kit-8 evaluated chondrocyte viability. Western blotting analyzed the expression levels of collagen II, aggrecan, SOX9, inducible nitric oxide synthase (iNOS), IL-6, matrix metalloproteinases (MMPs: MMP1, MMP3, and MMP13), and signalling molecules associated with nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways. Immunofluorescence analysis assessed the expression of aggrecan, collagen II, MMP13, and p-P65. In vivo, a destabilized medial meniscus (DMM) surgery was used to induce mice OA knee joints. After injection of DHCA or a vehicle into the injured joints, histological staining gauged the severity of cartilage damage. Results. DHCA prevented iNOS and IL-6 from being upregulated by IL-1β. Moreover, the IL-1β-induced upregulation of MMPs could be inhibited by DHCA. Additionally, the administration of DHCA counteracted IL-1β-induced downregulation of aggrecan, collagen II, and SOX9. DHCA protected articular cartilage by blocking the NF-κB and MAPK pathways. Furthermore, DHCA mitigated the destruction of articular cartilage in vivo. Conclusion. We present evidence that DHCA alleviates inflammation and cartilage degradation in OA chondrocytes via suppressing the NF-κB and MAPK pathways, indicating that DHCA may be a potential agent for OA treatment. Cite this article: Bone Joint Res 2023;12(4):259–273

Aims. To investigate the extent of bone development around the scaffold of custom triflange acetabular components (CTACs) over time. Methods. We performed a single-centre historical prospective cohort study, including all patients with revision THA using the aMace CTAC between January 2017 and March 2021. A total of 18 patients (18 CTACs) were included. Models of the hemipelvis and the scaffold component of the CTACs were created by segmentation of CT scans. The CT scans were performed immediately postoperatively and at least one year after surgery. The amount of bone in contact with the scaffold was analyzed at both times, and the difference was calculated. Results. The mean time between the implantation and the second CT scan was two years (1 to 5). The mean age of the patients during CTAC implantation was 75 years (60 to 92). The mean scaffold-bone contact area increased from 16% (SD 12.6) to 28% (SD 11.9). The mean scaffold-bone distance decreased from a mean of 6.5 mm (SD 2.0) to 5.5 mm (SD 1.6). None of the CTACs were revised or radiologically loose. Conclusion. There was a statistically significant increase of scaffold-bone contact area over time, but the total contact area of the scaffold in relation to the acetabular bone remained relatively low. As all implants remained well fixed, the question remains to what extend the scaffold contributes to the observed stability, in relation to the screws. A future design implication might be an elimination of the bulky scaffold component. This design modification would reduce production costs and may optimize the primary fit of the implant. Cite this article: Bone Joint J 2024;106-B(4):359–364

Aims. The aim of this study was to perform the first population-based description of the epidemiological and health economic burden of fracture-related infection (FRI). Methods. This is a retrospective cohort study of operatively managed orthopaedic trauma patients from 1 January 2007 to 31 December 2016, performed in Queensland, Australia. Record linkage was used to develop a person-centric, population-based dataset incorporating routinely collected administrative, clinical, and health economic information. The FRI group consisted of patients with International Classification of Disease 10th Revision diagnosis codes for deep infection associated with an implanted device within two years following surgery, while all others were deemed not infected. Demographic and clinical variables, as well as healthcare utilization costs, were compared. Results. There were 111,402 patients operatively managed for orthopaedic trauma, with 2,775 of these (2.5%) complicated by FRI. The development of FRI had a statistically significant association with older age, male sex, residing in rural/remote areas, Aboriginal or Torres Strait Islander background, lower socioeconomic status, road traffic accident, work-related injuries, open fractures, anatomical region (lower limb, spine, pelvis), high injury severity, requiring soft-tissue coverage, and medical comorbidities (univariate analysis). Patients with FRI had an eight-times longer median inpatient length of stay (24 days vs 3 days), and a 2.8-times higher mean estimated inpatient hospitalization cost (AU$56,565 vs AU$19,773) compared with uninfected patients. The total estimated inpatient cost of the FRI cohort to the healthcare system was AU$156.9 million over the ten-year period. Conclusion. The results of this study advocate for improvements in trauma care and infection management, address social determinants of health, and highlight the upside potential to improve prevention and treatment strategies. Cite this article: Bone Joint J 2024;106-B(1):77–85

Aims. Musculoskeletal infection is a devastating complication in both trauma and elective orthopaedic surgeries that can result in significant morbidity. Aim of this study was to assess the effectiveness and complications of local antibiotic impregnated dissolvable synthetic calcium sulphate beads (Stimulan Rapid Cure) in the hands of different surgeons from multiple centres in surgically managed bone and joint infections. Methods. Between January 2019 and December 2022, 106 patients with bone and joint infections were treated by five surgeons in five hospitals. Surgical debridement and calcium sulphate bead insertion was performed for local elution of antibiotics in high concentration. In all, 100 patients were available for follow-up at regular intervals. Choice of antibiotic was tailor made for each patient in consultation with microbiologist based on the organism grown on culture and the sensitivity. In majority of our cases, we used a combination of vancomycin and culture sensitive heat stable antibiotic after a thorough debridement of the site. Primary wound closure was achieved in 99 patients and a split skin graft closure was done in one patient. Mean follow-up was 20 months (12 to 30). Results. Overall, six out of 106 patients (5.6%) presented with sepsis and poorly controlled comorbid conditions, and died in the hospital within few days of index surgery. Out of the remaining 100 patients, control of infection was achieved in 95 patients (95%). Persistence of infection was noted in five (5%) patients. Out of these 95 patients that had good control of infection, four patients (4.2%) with gap nonunion needed Masquelet procedure to achieve union. Conclusion. Our multicentre experience confirmed that surgical debridement along with calcium sulphate bead insertion was effective in treating bone and joint infections without any side effects and complications. Cite this article: Bone Jt Open 2023;4(7):516–522

Aims. To identify factors influencing clinicians’ decisions to undertake a nonoperative hip fracture management approach among older people, and to determine whether there is global heterogeneity regarding these factors between clinicians from high-income countries (HIC) and low- and middle-income countries (LMIC). Methods. A SurveyMonkey questionnaire was electronically distributed to clinicians around the world through the Fragility Fracture Network (FFN)’s Perioperative Special Interest Group and clinicians’ personal networks between 24 May and 25 July 2021. Analyses were performed using Excel and STATA v16.0. Between-group differences were determined using independent-samples t-tests and chi-squared tests. Results. A total of 406 respondents from 51 countries answered the questionnaire, of whom 225 came from HIC and 180 from LMIC. Clinicians from HIC reported a greater median and mean estimated proportion of admitted patients with hip fracture undergoing surgery (median 96% (interquartile range (IQR) 95% to 99%); mean 94% (SD 8%)) than those from LMIC (median 85% (IQR 75% to 95%); mean 81% (SD 16%); p < 0.001). Global heterogeneity seems to exist regarding factors such as anticipated life expectancy, insufficient resources, ability to pay, treatment costs, and perception of risk in hip fracture management decision-making. Conclusion. This study represents the first international sampling of clinician perspectives regarding nonoperative hip fracture management. Several factors seemed to influence the clinician decision-making process. Further research is needed to inform the development of best practice guidelines to improve decision-making and the quality of hip fracture care among older people. Cite this article: Bone Jt Open 2023;4(10):766–775

Aims. Early large treatment effects can arise in small studies, which lessen as more data accumulate. This study aimed to retrospectively examine whether early treatment effects occurred for two multicentre orthopaedic randomized controlled trials (RCTs) and explore biases related to this. Methods. Included RCTs were ProFHER (PROximal Fracture of the Humerus: Evaluation by Randomisation), a two-arm study of surgery versus non-surgical treatment for proximal humerus fractures, and UK FROST (United Kingdom Frozen Shoulder Trial), a three-arm study of two surgical and one non-surgical treatment for frozen shoulder. To determine whether early treatment effects were present, the primary outcome of Oxford Shoulder Score (OSS) was compared on forest plots for: the chief investigator’s (CI) site to the remaining sites, the first five sites opened to the other sites, and patients grouped in quintiles by randomization date. Potential for bias was assessed by comparing mean age and proportion of patients with indicators of poor outcome between included and excluded/non-consenting participants. Results. No bias in treatment effect was observed overall for the CI site, or the first five sites, compared with the remaining sites in either trial. An early treatment effect on the OSS was observed for the first quintile of participants recruited to ProFHER only (clinically relevant difference of seven points). Selection bias for age was observed in the ProFHER trial only, with slightly younger patients being recruited into the study. Both trials showed some selection bias for markers of poor prognosis, although these did not appear to change over time. Conclusion. No bias in treatment effects overall were found at the CI or early sites set-up. An early treatment effect was found in one of the two trials, which was likely a chance effect as this did not continue during the study. Selection bias was observed in both RCTs, however this was minimal and did not impact on outcome. Cite this article: Bone Jt Open 2023;4(2):96–103

Aims. The Bankart and Latarjet procedures are two of the most common surgical techniques to treat anterior shoulder instability with satisfactory clinical and functional outcomes. However, the outcomes in the adolescent population remain unclear, and there is no information regarding the arthroscopic Latarjet in this population. The purpose of this study was to evaluate the outcomes of the arthroscopic Bankart and arthroscopic Latarjet procedures in the management of anterior shoulder instability in adolescents. Methods. We present a retrospective, matched-pair study of teenagers with anterior glenohumeral instability treated with an arthroscopic Bankart repair (ABR) or an arthroscopic Latarjet (AL) procedure with a minimum two-year follow-up. Preoperative demographic and clinical features, factors associated with dislocation, and complications were collected. Recurrence, defined as dislocation or subluxation, was established as the primary outcome. Clinical and functional outcomes were analyzed using objective (Rowe), and subjective (Western Ontario Shoulder Instability Index (WOSI) and Single Assessment Numeric Evaluation (SANE)) scores. Additionally, the rate of return to sport was assessed. Results. A total of 51 adolescents were included, of whom 46 (92%) were male, with 17 (33%) in the Latarjet group and 34 (66%) in the Bankart group. The mean age at time of surgery was 18 years (15 to 19). There were no intraoperative complications. At a median follow-up of nine years (IQR 2 to 18), recurrence was observed in 12 patients in the Bankart group (35.3%) and one patient in the Latarjet group (5.9%) (p = 0.023). Satisfactory postoperative outcomes were obtained, with mean Rowe, WOSI, and SANE scores noted at 95 (10 to 100), 325 (25 to 1,975), and 87.5 (10 to 100), respectively. Most patients (29 in the Bankart group (85.3%) and 16 in the Latarjet group (94.1%)) were able to return to sport (p = 0.452). Conclusion. The ABR and AL procedures both obtain satisfactory clinical and functional outcomes in the treatment of anterior glenohumeral instability in adolescents with a low complication rate. However, the ABR is associated with a significantly higher recurrence rate. Cite this article: Bone Jt Open 2024;5(11):1041–1048

Aims. This study aimed to develop and validate a fully automated system that quantifies proximal femoral bone mineral density (BMD) from CT images. Methods. The study analyzed 978 pairs of hip CT and dual-energy X-ray absorptiometry (DXA) measurements of the proximal femur (DXA-BMD) collected from three institutions. From the CT images, the femur and a calibration phantom were automatically segmented using previously trained deep-learning models. The Hounsfield units of each voxel were converted into density (mg/cm. 3. ). Then, a deep-learning model trained by manual landmark selection of 315 cases was developed to select the landmarks at the proximal femur to rotate the CT volume to the neutral position. Finally, the CT volume of the femur was projected onto the coronal plane, and the areal BMD of the proximal femur (CT-aBMD) was quantified. CT-aBMD correlated to DXA-BMD, and a receiver operating characteristic (ROC) analysis quantified the accuracy in diagnosing osteoporosis. Results. CT-aBMD was successfully measured in 976/978 hips (99.8%). A significant correlation was found between CT-aBMD and DXA-BMD (r = 0.941; p < 0.001). In the ROC analysis, the area under the curve to diagnose osteoporosis was 0.976. The diagnostic sensitivity and specificity were 88.9% and 96%, respectively, with the cutoff set at 0.625 g/cm. 2. . Conclusion. Accurate DXA-BMD measurements and diagnosis of osteoporosis were performed from CT images using the system developed herein. As the models are open-source, clinicians can use the proposed system to screen osteoporosis and determine the surgical strategy for hip surgery. Cite this article: Bone Joint Res 2023;12(9):590–597

Aims. Rotator cuff muscle atrophy and fatty infiltration affect the clinical outcomes of rotator cuff tear patients. However, there is no effective treatment for fatty infiltration at this time. High-intensity interval training (HIIT) helps to activate beige adipose tissue. The goal of this study was to test the role of HIIT in improving muscle quality in a rotator cuff tear model via the β3 adrenergic receptor (β3AR). Methods. Three-month-old C57BL/6 J mice underwent a unilateral rotator cuff injury procedure. Mice were forced to run on a treadmill with the HIIT programme during the first to sixth weeks or seventh to 12th weeks after tendon tear surgery. To study the role of β3AR, SR59230A, a selective β3AR antagonist, was administered to mice ten minutes before each exercise through intraperitoneal injection. Supraspinatus muscle, interscapular brown fat, and inguinal subcutaneous white fat were harvested at the end of the 12th week after tendon tear and analyzed biomechanically, histologically, and biochemically. Results. Histological analysis of supraspinatus muscle showed that HIIT improved muscle atrophy, fatty infiltration, and contractile force compared to the no exercise group. In the HIIT groups, supraspinatus muscle, interscapular brown fat, and inguinal subcutaneous white fat showed increased expression of tyrosine hydroxylase and uncoupling protein 1, and upregulated the β3AR thermogenesis pathway. However, the effect of HIIT was not present in mice injected with SR59230A, suggesting that HIIT affected muscles via β3AR. Conclusion. HIIT improved supraspinatus muscle quality and function after rotator cuff tears by activating systemic sympathetic nerve fibre near adipocytes and β3AR. Cite this article: Bone Joint Res 2023;12(8):455–466

Aims. To perform an incremental cost-utility analysis and assess the impact of differential costs and case volume on the cost-effectiveness of robotic arm-assisted unicompartmental knee arthroplasty (rUKA) compared to manual (mUKA). Methods. This was a five-year follow-up study of patients who were randomized to rUKA (n = 64) or mUKA (n = 65). Patients completed the EuroQol five-dimension questionnaire (EQ-5D) preoperatively, and at three months and one, two, and five years postoperatively, which was used to calculate quality-adjusted life years (QALYs) gained. Costs for the primary and additional surgery and healthcare costs were calculated. Results. rUKA was associated with a relative 0.012 QALY gain at five years, which was associated with an incremental cost per QALY of £13,078 for a unit undertaking 400 cases per year. A cost per QALY of less than £20,000 was achieved when ≥ 300 cases were performed per year. However, on removal of the cost for a revision for presumed infection (mUKA group, n = 1) the cost per QALY was greater than £38,000, which was in part due to the increased intraoperative consumable costs associated with rUKA (£626 per patient). When the absolute cost difference (operative and revision costs) was less than £240, a cost per QALY of less than £20,000 was achieved. On removing the cost of the revision for infection, rUKA was cost-neutral when more than 900 cases per year were undertaken and when the consumable costs were zero. Conclusion. rUKA was a cost-effective intervention with an incremental cost per QALY of £13,078 at five years, however when removing the revision for presumed infection, which was arguably a random event, this was no longer the case. The absolute cost difference had to be less than £240 to be cost-effective, which could be achieved by reducing the perioperative costs of rUKA or if there were increased revision costs associated with mUKA with longer follow-up. Cite this article: Bone Jt Open 2023;4(11):889–898

Aims. A review of the literature on elbow replacement found no consistency in the clinical outcome measures which are used to assess the effectiveness of interventions. The aim of this study was to define core outcome domains for elbow replacement. Methods. A real-time Delphi survey was conducted over four weeks using outcomes from a scoping review of 362 studies on elbow replacement published between January 1990 and February 2021. A total of 583 outcome descriptors were rationalized to 139 unique outcomes. The survey consisted of 139 outcomes divided into 18 domains. The readability and clarity of the survey was determined by an advisory group including a patient representative. Participants were able to view aggregated responses from other participants in real time and to revisit their responses as many times as they wished during the study period. Participants were able to propose additional items for inclusion. A Patient and Public Inclusion and Engagement (PPIE) panel considered the consensus findings. Results. A total of 45 respondents completed the survey. Nine core mandatory domains were identified: ‘return to work or normal daily role’; delivery of care was measured in the domains ‘patient satisfaction with the outcome of surgery’ and ‘would the patient have the same operation again’; ‘pain’; ‘revision’; ‘elbow function’; ‘independence in activities of daily living’; ‘health-related quality of life’; and ‘adverse events’. ‘Elbow range of motion’ was identified as important by consensus but was felt to be less relevant by the PPIE panel. The PPIE panel unanimously stated that pain should be used as the primary outcome domain. Conclusion. This study defined core domains for the clinical outcomes of elbow replacement obtained by consensus from patients, carers, and healthcare professionals. Pain may be used as the primary outcome in future studies, where appropriate. Further work is required to define the instruments that should be used. Cite this article: Bone Joint J 2024;106-B(11):xxx–xxx

Aims. Hyaline cartilage has a low capacity for regeneration. Untreated osteochondral lesions of the femoral head can lead to progressive and symptomatic osteoarthritis of the hip. The purpose of this study is to analyze the clinical and radiological long-term outcome of patients treated with osteochondral autograft transfer. To our knowledge, this study represents a series of osteochondral autograft transfer of the hip with the longest follow-up. Methods. We retrospectively evaluated 11 hips in 11 patients who underwent osteochondral autograft transfer in our institution between 1996 and 2012. The mean age at the time of surgery was 28.6 years (8 to 45). Outcome measurement included standardized scores and conventional radiographs. Kaplan-Meier survival curve was used to determine the failure of the procedures, with conversion to total hip arthroplasty (THA) defined as the endpoint. Results. The mean follow-up of patients treated with osteochondral autograft transfer was 18.5 years (9.3 to 24.7). Six patients developed osteoarthritis and had a THA at a mean of 10.3 years (1.1 to 17.3). The cumulative survivorship of the native hips was 91% (95% confidence interval (CI) 74 to 100) at five years, 62% (95% CI 33 to 92) at ten years, and 37% (95% CI 6 to 70) at 20 years. Conclusion. This is the first study analyzing the long-term results of osteochondral autograft transfer of the femoral head. Although most patients underwent conversion to THA in the long term, over half of them survived more than ten years. Osteochondral autograft transfer could be a time-saving procedure for young patients with devastating hip conditions who have virtually no other surgical options. A larger series or a similar matched cohort would be necessary to confirm these results which, in view of the heterogeneity of our series, seems difficult to achieve. Cite this article: Bone Jt Open 2023;4(7):523–531

Aims. We aimed to assess the cumulative risk of total hip arthroplasty (THA) from in situ fixation for slipped capital femoral epiphysis (SCFE) after a follow-up of almost 50 years. Methods. In this study, 138 patients with 172 affected hips treated with in situ fixation were evaluated retrospectively. A total of 97 patients (70%) were male and the mean age was 13.6 years (SD 2.1); 35 patients (25%) had a bilateral disease. The median follow-up time was 49 years (interquartile range 43 to 55). Basic demographic, stability, and surgical details were obtained from patient records. Preoperative radiographs (slip angle; SA) were measured, and data on THA was gathered from the Finnish National Arthroplasty Register. Results. The preoperative SA was a mean of 39° (SD 19°). At follow-up, 56 of the patients had undergone THA for a hip previously fixed in situ for SCFE (41%) and 64 of all affected hips had been replaced (37%). Kaplan-Meier analysis gave a median prosthesis-free postoperative survival of 55 years (95% confidence interval (CI) 45 to 64) for the affected hips. In a multivariate analysis, female patients had a two-fold risk for THA (hazard ratio (HR) 2.42 (95% CI 1.16 to 5.07)) and a greater preoperative SA increased the risk of THA (HR 1.03 for every increment of 1° (95% CI 1.01 to 1.05)), while patient age at surgery, slip laterality, stability of slip, or diagnostic delay did not have a statistically significant effect on the risk of THA. Conclusion. SCFE treated primarily with in situ fixation may lead to THA in more than 40% of affected hips at a near 50-year follow-up. This risk is approximately 15-times the reported lifetime risk in the Finnish general population. Female sex and increasing preoperative SA significantly predicted higher risk of THA. Cite this article: Bone Joint J 2023;105-B(12):1321–1326

Aims. Prophylactic antibiotic regimens for elective primary total hip and knee arthroplasty vary widely across hospitals and trusts in the UK. This study aimed to identify antibiotic prophylaxis regimens currently in use for elective primary arthroplasty across the UK, establish variations in antibiotic prophylaxis regimens and their impact on the risk of periprosthetic joint infection (PJI) in the first-year post-index procedure, and evaluate adherence to current international consensus guidance. Methods. The guidelines for the primary and alternative recommended prophylactic antibiotic regimens in clean orthopaedic surgery (primary arthroplasty) for 109 hospitals and trusts across the UK were sought by searching each trust and hospital’s website (intranet webpages), and by using the MicroGuide app. The mean cost of each antibiotic regimen was calculated using price data from the British National Formulary (BNF). Regimens were then compared to the 2018 Philadelphia Consensus Guidance, to evaluate adherence to international guidance. Results. The primary choice and dosing of the prophylactic antimicrobial regimens varied widely. The two most used regimens were combined teicoplanin and gentamicin, and cefuroxime followed by two or three doses of cefuroxime eight-hourly, recommended by 24 centres (22.02%) each. The alternative choice and dosing of the prophylactic antimicrobial regimen also varied widely across the 83 centres with data available. Prophylaxis regimens across some centres fail to cover the likeliest causes of surgical site infection (SSI). Five centres (4.59%) recommend co-amoxiclav, which confers no Staphylococcus coverage, while 33 centres (30.28%) recommend cefuroxime, which confers no Enterococcus coverage. Limited adherence to 2018 Philadelphia Consensus Guidance was observed, with 67 centres (61.50%) not including a cephalosporin in their guidance. Conclusion. This analysis of guidance on antimicrobial prophylaxis in primary arthroplasty across 109 hospitals and trusts in the UK has identified widespread variation in primary and alternative antimicrobial regimens currently recommended. Cite this article: Bone Jt Open 2023;4(10):742–749

Aims. This study aimed to compare the outcomes of two different postoperative management approaches following surgical fixation of ankle fractures: traditional cast immobilization versus the Early Motion and Directed Exercise (EMADE) programme. Methods. A total of 157 patients aged 18 years or older who underwent successful open reduction and internal fixation (ORIF) of Weber B (AO44B) ankle fractures were recruited to this randomized controlled trial. At two weeks post-surgical fixation, participants were randomized to either light-weight cast-immobilization or the EMADE programme, consisting of progressive home exercises and weekly advice and education. Both groups were restricted to non-weightbearing until six weeks post-surgery. The primary outcome was assessed using the Olerud-Molander Ankle Score (OMAS) questionnaire at 12 weeks post-surgery, with secondary measures at two, six, 24, and 52 weeks. Exploratory cost-effectiveness analyses were also performed. Results. Overall, 130 participants returned their 12-week OMAS questionnaires. The mean OMAS was significantly higher in the EMADE group compared with the immobilized group (62.0 (SD 20.9) vs 48.8 (SD 22.5)), with a clinically meaningful mean difference of 13.2 (95% CI 5.66 to 20.73; p < 0.001). These differences were maintained at week 24, with convergence by week 52. No intervention-related adverse events, including instability, were reported. Conclusion. The EMADE programme demonstrated an accelerated recovery compared to traditional six-week cast immobilization for those who have undergone ORIF surgery to stabilize Weber B (AO44B) ankle fractures. The study found the EMADE intervention to be safe. Cite this article: Bone Joint J 2024;106-B(9):949–956

Aims. Body exhaust suits or surgical helmet systems (colloquially, ‘space suits’) are frequently used in many forms of arthroplasty, with the aim of providing personal protection to surgeons and, perhaps, reducing periprosthetic joint infections, although this has not consistently been borne out in systematic reviews and registry studies. To date, no large-scale study has investigated whether this is applicable to shoulder arthroplasty. We used the New Zealand Joint Registry to assess whether the use of surgical helmet systems was associated with lower all-cause revision or revision for deep infection in primary shoulder arthroplasties. Methods. We analyzed 16,000 shoulder arthroplasties (hemiarthroplasties, anatomical, and reverse geometry prostheses) recorded on the New Zealand Joint Registry from its inception in 2000 to the present day. We assessed patient factors including age, BMI, sex, and American Society of Anesthesiologists (ASA) grade, as well as whether or not the operation took place in a laminar flow operating theatre. Results. A total of 2,728 operations (17%) took place using surgical helmet systems. Patient cohorts were broadly similar in terms of indication for surgery (osteoarthritis, rheumatoid arthritis, fractures) and medical comorbidities (age and sex). There were 842 revisions (5% of cases) with just 98 for deep infection (0.6% of all cases or 11.6% of the revisions). There were no differences in all-cause revisions or revision for deep infection between the surgical helmet systems and conventional gowns (p = 0.893 and p = 0.911, respectively). Conclusion. We found no evidence that wearing a surgical helmet system reduces the incidence of periprosthetic joint infection in any kind of primary shoulder arthroplasty. We acknowledge the limitations of this registry study and accept that there may be other benefits in terms of personal protection, comfort, or visibility. However, given their financial and ecological footprint, they should be used judiciously in shoulder surgery. Cite this article: Bone Jt Open 2024;5(10):894–897

Aims. Osteoarthritis (OA) is the most common chronic pathema of human joints. The pathogenesis is complex, involving physiological and mechanical factors. In previous studies, we found that ferroptosis is intimately related to OA, while the role of Sat1 in chondrocyte ferroptosis and OA, as well as the underlying mechanism, remains unclear. Methods. In this study, interleukin-1β (IL-1β) was used to simulate inflammation and Erastin was used to simulate ferroptosis in vitro. We used small interfering RNA (siRNA) to knock down the spermidine/spermine N1-acetyltransferase 1 (Sat1) and arachidonate 15-lipoxygenase (Alox15), and examined damage-associated events including inflammation, ferroptosis, and oxidative stress of chondrocytes. In addition, a destabilization of the medial meniscus (DMM) mouse model of OA induced by surgery was established to investigate the role of Sat1 inhibition in OA progression. Results. The results showed that inhibition of Sat1 expression can reduce inflammation, ferroptosis changes, reactive oxygen species (ROS) level, and lipid-ROS accumulation induced by IL-1β and Erastin. Knockdown of Sat1 promotes nuclear factor-E2-related factor 2 (Nrf2) signalling. Additionally, knockdown Alox15 can alleviate the inflammation-related protein expression induced by IL-1β and ferroptosis-related protein expression induced by Erastin. Furthermore, knockdown Nrf2 can reverse these protein expression alterations. Finally, intra-articular injection of diminazene aceturate (DA), an inhibitor of Sat1, enhanced type II collagen (collagen II) and increased Sat1 and Alox15 expression. Conclusion. Our results demonstrate that inhibition of Sat1 could alleviate chondrocyte ferroptosis and inflammation by downregulating Alox15 activating the Nrf2 system, and delaying the progression of OA. These findings suggest that Sat1 provides a new approach for studying and treating OA. Cite this article: Bone Joint Res 2024;13(3):110–123

Aims. We sought to compare functional outcomes and survival between non-smokers, former smokers, and current smokers who underwent anatomical total shoulder arthroplasty (aTSA) in a large cohort of patients. Methods. A retrospective review of a prospectively collected shoulder arthroplasty database was performed between August 1991 and September 2020 to identify patients who underwent primary aTSA. Patients were excluded for preoperative diagnoses of fracture, infection, or oncological disease. Three cohorts were created based on smoking status: non-smokers, former smokers, and current smokers. Outcome scores (American Shoulder and Elbow Surgeons (ASES), Constant-Murley score, Shoulder Pain and Disability Index (SPADI), Simple Shoulder Test (SST), University of California, Los Angeles activity scale (UCLA)), range of motion (external rotation (ER), forward elevation (FE), internal rotation, abduction), and shoulder strength (ER, FE) evaluated at two- to four-year follow-up were compared between cohorts. Evaluation of revision-free survival was performed using the Kaplan-Meier method to final follow-up. Results. We included 428 primary aTSAs with a mean follow-up of 2.4 years (SD 0.6). Our cohort consisted of 251 non-smokers, 138 former smokers who quit a mean 21 years (SD 14) prior to surgery (25 pack-years (SD 22)), and 39 current smokers (23 pack-years (SD 20)). At two- to four-year follow-up, former smokers had less favourable SPADI, SST, and FE strength compared to non-smokers, and current smokers had less favourable SPADI, SST, ASES score, UCLA score, Constant-Murley score, FE, abduction, and ER strength compared to non-smokers. Non-smokers exhibited higher revision-free survival rates at two, five, eight, and ten years postoperatively compared to former smokers and current smokers, who had similar rates. Conclusion. Our study suggests that smoking has a negative effect on aTSA functional outcomes that may persist even after quitting. Cite this article: Bone Joint J 2024;106-B(11):1263–1272

Aims. This multicentre retrospective observational study’s aims were to investigate whether there are differences in the occurrence of radiolucent lines (RLLs) following total knee arthroplasty (TKA) between the conventional Attune baseplate and its successor, the novel Attune S+, independent from other potentially influencing factors; and whether tibial baseplate design and presence of RLLs are associated with differing risk of revision. Methods. A total of 780 patients (39% male; median age 70.7 years (IQR 62.0 to 77.2)) underwent cemented TKA using the Attune Knee System) at five centres, and with the latest radiograph available for the evaluation of RLL at between six and 36 months from surgery. Univariate and multivariate logistic regression models were performed to assess associations between patient and implant-associated factors on the presence of tibial and femoral RLLs. Differences in revision risk depending on RLLs and tibial baseplate design were investigated with the log-rank test. Results. The conventional and novel Attune baseplates were used in 349 (45%) and 431 (55%) patients, respectively. At a median follow-up of 14 months (IQR 11 to 25), RLLs were present in 29% (n = 228/777) and 15% (n = 116/776) of the tibial and femoral components, respectively, and were more common in the conventional compared to the novel baseplate. The novel baseplate was independently associated with a lower incidence of tibial and femoral RLLs (both regardless of age, sex, BMI, and time to radiograph). One- and three-year revision risk was 1% (95% CI 0.4% to 1.9%)and 6% (95% CI 2.6% to 13.2%), respectively. There was no difference between baseplate design and the presence of RLLs on the the risk of revision at short-term follow-up. Conclusion. The overall incidence of RLLs, as well as the incidence of tibial and femoral RLLs, was lower with the novel compared to the conventional tibial Attune baseplate design, but higher than in the predecessor design and other commonly used TKA systems. Cite this article: Bone Joint J 2024;106-B(11):1240–1248

Aims. Tenosynovial giant cell tumour (TGCT) is a rare benign tumour of the musculoskeletal system. Surgical management is fraught with challenges due to high recurrence rates. The aim of this study was to describe surgical treatment and evaluate surgical outcomes of TGCT at an Australian tertiary referral centre for musculoskeletal tumours and to identify factors affecting recurrence rates. Methods. A prospective database of all patients with TGCT surgically managed by two orthopaedic oncology surgeons was reviewed. All cases irrespective of previous treatment were included and patients without follow-up were excluded. Pertinent tumour characteristics and surgical outcomes were collected for analysis. Results. There were 111 total cases included in the study; 71 (64%) were female, the mean age was 36 years (SD 13.6), and the knee (n = 64; 57.7%) was the most commonly affected joint. In all, 60 patients (54.1%) had diffuse-type (D-TGCT) disease, and 94 patients (84.7%) presented therapy-naïve as "primary cases" (PC). The overall recurrence rate was 46.8% for TGCT. There was a statistically significant difference in recurrence rates between D-TGCT and localized disease (75.0% vs 13.7%, relative risk (RR) 3.40, 95% confidence interval (CI) 2.17 to 5.34; p < 0.001), and for those who were referred in the ”revision cases” (RC) group compared to the PC group (82.4% vs 48.9%, RR 1.68, 95% CI 1.24 to 2.28; p = 0.011). Age, sex, tumour volume, and mean duration of symptoms were not associated with recurrence (p > 0.05). Conclusion. Recurrence rates remain high even at a tertiary referral hospital. Highest rates are seen in D-TGCT and “revision cases”. Due to the risks of recurrence, the complexity of surgery, and the need for adjuvant therapy, this paper further supports the management of TGCT in a tertiary referral multi-disciplinary orthopaedic oncology service. Cite this article: Bone Jt Open 2023;4(11):846–852