We assessed 100 patients with a primary total hip replacement using the Harris hip score and the Nottingham Health Profile at one, three and five years after operation. They were derived from two prospective randomised series of cemented and uncemented replacements.

Both scoring systems correlated highly and were each heavily influenced by the system of functional classification defined by Charnley. After five years both reflected the function of the implant and the general state of the patient. A higher degree of sensitivity is needed to show differences in the performance of an implant in the short and medium term. We do not yet have an ideal system of clinical assessment and the overall function must always be properly assessed.

Subtrochanteric osteotomy has been reported to interrupt the destructive phase of coxa plana and speed up the rate of healing. The aim of this investigation was to test the validity of these statements. The material comprised twenty-five patients treated by osteotomy and thirty-three patients treated by support in a Thomas's splint. For every patient the extent of the radiological changes was estimated and plotted against time as a percentage of the normal epiphysial volume. The graph so obtained represents the rate of destruction and re-ossification, as well as the maximum involvement of the epiphysis. The curves for each group of patients were superimposed in a graph with all the minima coincident in time. The two patterns of curves are closely similar. It was confirmed statistically that the rates of destruction and re-ossification did not differ between the two groups. The results afford no evidence that osteotomy interrupts the disease or speeds up healing.

Aims. Reimers migration percentage (MP) is a key measure to inform decision-making around the management of hip displacement in cerebral palsy (CP). The aim of this study is to assess validity and inter- and intra-rater reliability of a novel method of measuring MP using a smart phone app (HipScreen (HS) app). Methods. A total of 20 pelvis radiographs (40 hips) were used to measure MP by using the HS app. Measurements were performed by five different members of the multidisciplinary team, with varying levels of expertise in MP measurement. The same measurements were repeated two weeks later. A senior orthopaedic surgeon measured the MP on picture archiving and communication system (PACS) as the gold standard and repeated the measurements using HS app. Pearson’s correlation coefficient (r) was used to compare PACS measurements and all HS app measurements and assess validity. Intraclass correlation coefficient (ICC) was used to assess intra- and inter-rater reliability. Results. All HS app measurements (from 5 raters at week 0 and week 2 and PACS rater) showed highly significant correlation with the PACS measurements (p < 0.001). Pearson’s correlation coefficient (r) was constantly over 0.9, suggesting high validity. Correlation of all HS app measures from different raters to each other was significant with r > 0.874 and p < 0.001, which also confirms high validity. Both inter- and intra-rater reliability were excellent with ICC > 0.9. In a 95% confidence interval for repeated measurements, the deviation of each specific measurement was less than 4% MP for single measurer and 5% for different measurers. Conclusion. The HS app provides a valid method to measure hip MP in CP, with excellent inter- and intra-rater reliability across different medical and allied health specialties. This can be used in hip surveillance programmes by interdisciplinary measurers. Cite this article: Bone Jt Open 2023;4(5):363–369

Aims. A core outcome set for adult, open lower limb fracture has been established consisting of ‘Walking, gait and mobility’, ‘Being able to return to life roles’, ‘Pain or discomfort’, and ‘Quality of life’. This study aims to identify which outcome measurement instruments (OMIs) should be recommended to measure each core outcome. Methods. A systematic review and quality assessment were conducted to identify existing instruments with evidence of good measurement properties in the open lower limb fracture population for each core outcome. Additionally, shortlisting criteria were developed to identify suitable instruments not validated in the target population. Candidate instruments were presented, discussed, and voted on at a consensus meeting of key stakeholders. Results. The Wales Lower Limb Trauma Recovery scale was identified, demonstrating validation evidence in the target population. In addition, ten candidate OMIs met the shortlisting criteria. Six patients, eight healthcare professionals, and 11 research methodologists attended the consensus meeting. Consensus was achieved for the EuroQol five-dimension five-level questionnaire (EQ-5D-5L) and the Lower Extremity Functional Scale (LEFS) to measure ‘Quality of life’ and ‘Walking, gait and mobility’ in future research trials, audit, and clinical assessment, respectively. No instrument met consensus criteria to measure ‘Being able to return to life roles’ and ‘Pain or discomfort’. However, the EQ-5D-5L was found to demonstrate good face validity and could also be used pragmatically to measure these two outcomes, accepting limitations in sensitivity. Conclusion. This study recommends the LEFS and EQ-5D-5L to measure the core outcome set for adult open lower limb fracture. Cite this article: Bone Joint Res 2023;12(6):352–361

Aims. The open Latarjet procedure is a widely used treatment for recurrent anterior instability of the shoulder. Although satisfactory outcomes are reported, factors which influence a patient’s experience are poorly quantified. The aim of this study was to evaluate the effect of a range of demographic factors and measures of the severity of instability on patient-reported outcome measures in patients who underwent an open Latarjet procedure at a minimum follow-up of two years. Methods. A total of 350 patients with anterior instability of the shoulder who underwent an open Latarjet procedure between 2005 and 2018 were reviewed prospectively, with the collection of demographic and psychosocial data, preoperative CT, and complications during follow-up of two years. The primary outcome measure was the Western Ontario Shoulder Instability Index (WOSI), assessed preoperatively, at two years postoperatively, and at mid-term follow-up at a mean of 50.6 months (SD 24.8) postoperatively. The secondary outcome measure was the abbreviated version of the Disabilities of the Arm, Shoulder and Hand (QuickDASH) score. The influence of the demographic details of the patients, measurements of the severity of instability, and the complications of surgery were assessed in a multivariate analysis. Results. The mean age of the patients was 25.5 years (22 to 32) and 27 (7.7%) were female. The median time to surgery after injury was 19 months (interquartile range (IQR) 13 to 39). Seven patients developed clinically significant complications requiring further intervention within two years of surgery. The median percentage WOSI deficiency was 8.0% (IQR 4 to 20) and median QuickDASH was 3.0 (IQR 0 to 9) at mid-term assessment. A minority of patients reported a poorer experience, and 22 (6.3%) had a > 50% deficiency in WOSI score. Multivariate analysis revealed that consumption of ≥ 20 units of alcohol/week, a pre-existing affective disorder or epilepsy, medicolegal litigation, increasing time to surgery, and residing in a more socioeconomically deprived area were independently predictive of a poorer WOSI score. Conclusion. Although most patients treated by an open Latarjet procedure have excellent outcomes at mid-term follow-up, a minority have poorer outcomes, which are mainly predictable from pre-existing demographic factors, rather than measures of the severity of instability. Cite this article: Bone Joint J 2023;105-B(4):389–399

Aims. Open lower limb fracture is a life-changing injury affecting 11.5 per 100,000 adults each year, and causes significant morbidity and resource demand on trauma infrastructures. This study aims to identify what, and how, outcomes have been reported for people following open lower limb fracture over ten years. Methods. Systematic literature searches identified all clinical studies reporting outcomes for adults following open lower limb fracture between January 2009 and July 2019. All outcomes and outcome measurement instruments were extracted verbatim. An iterative process was used to group outcome terms under standardized outcome headings categorized using an outcome taxonomy. Results. A total of 532 eligible studies were identified, reporting 1,803 outcomes with 786 unique outcome terms, which collapsed to 82 standardized outcome headings. Overall 479 individual outcome measurement instruments were identified, including 298 outcome definitions, 27 patient- and 18 clinician-reported outcome measures, and six physical performance measures. The most-reported outcome was ‘bone union/healing’ reported in over 50% of included studies, while health-related quality of life was only measured in 6% of included studies. Conclusion. Outcomes reported for people recovering from open lower limb fracture are heterogeneous, liable to outcome reporting bias, and vary widely in the definitions and the measurement tools used to collect them. Outcomes likely to be important to patients, such as quality of life and measures of physical functioning, have been neglected. This systematic review identifies the need to unify outcome measures reported on patients recovering from open lower limb fracture; this may be addressed by creating a core outcome set. Cite this article: Bone Joint Res 2023;12(2):138–146

Aims. Within healthcare, several measures are used to quantify and compare the severity of health conditions. Two common measures are disability weight (DW), a context-independent value representing severity of a health state, and utility weight (UW), a context-dependent measure of health-related quality of life. Neither of these measures have previously been determined for developmental dysplasia of the hip (DDH). The aim of this study is to determine the DW and country-specific UWs for DDH. Methods. A survey was created using three different methods to estimate the DW: a preference ranking exercise, time trade-off exercise, and visual analogue scale (VAS). Participants were fully licensed orthopaedic surgeons who were contacted through national and international orthopaedic organizations. A global DW was calculated using a random effects model through an inverse-variance approach. A UW was calculated for each country as one minus the country-specific DW composed of the time trade-off exercise and VAS. Results. Over a four-month period, 181 surgeons participated in the survey, with 116 surgeons included in the final analysis. The global DW calculated to be 0.18 (0.11 to 0.24), and the country-specific UWs ranged from 0.26 to 0.89. Conclusion. This is the first time that a global disability weight and country-specific utility weights have been estimated for DDH, which should assist in economic evaluations and the development of health policy. The methodology may be applied to other orthopaedic conditions. Cite this article: Bone Jt Open 2023;4(3):120–128

Aims. The primary aim of this study was to assess the feasibility of recruiting and retaining patients to a patient-blinded randomized controlled trial comparing corticosteroid injection (CSI) to autologous protein solution (APS) injection for the treatment of subacromial shoulder pain in a community care setting. The study focused on recruitment rates and retention of participants throughout, and collected data on the interventions’ safety and efficacy. Methods. Participants were recruited from two community musculoskeletal treatment centres in the UK. Patients were eligible if aged 18 years or older, and had a clinical diagnosis of subacromial impingement syndrome which the treating clinician thought was suitable for treatment with a subacromial injection. Consenting patients were randomly allocated 1:1 to a patient-blinded subacromial injection of CSI (standard care) or APS. The primary outcome measures of this study relate to rates of recruitment, retention, and compliance with intervention and follow-up to determine feasibility. Secondary outcome measures relate to the safety and efficacy of the interventions. Results. A total of 53 patients were deemed eligible, and 50 patients (94%) recruited between April 2022 and October 2022. Overall, 49 patients (98%) complied with treatment. Outcome data were collected in 100% of participants at three months and 94% at six months. There were no significant adverse events. Both groups demonstrated improvement in patient-reported outcome measures over the six-month period. Conclusion. Our study shows that it is feasible to recruit to a patient-blinded randomized controlled trial comparing APS and CSI for subacromial pain in terms of clinical outcomes and health-resource use in the UK. Safety and efficacy data are presented. Cite this article: Bone Jt Open 2024;5(7):534–542

Aims. The aim of this study was to develop a core outcome set of what to measure in all future clinical research on hand fractures and joint injuries in adults. Methods. Phase 1 consisted of steps to identify potential outcome domains through systematic review of published studies, and exploration of the patient perspective through qualitative research, consisting of 25 semi-structured interviews and five focus groups. Phase 2 involved key stakeholder groups (patients, hand surgeons, and hand therapists) prioritizing the outcome domains via a three-round international Delphi survey, with a final consensus meeting to agree the final core outcome set. Results. The systematic review of 160 studies identified 74 outcome domains based on the World Health Organization International Classification of Functioning, Disability, and Health. Overall, 35 domains were generated through thematic analysis of the patient interviews and focus groups. The domains from these elements were synthesised to develop 37 outcome domains as the basis of the Delphi survey, with a further four generated from participant suggestions in Round 1. The Delphi survey identified 20 outcome domains as ‘very important’ for the core outcome set. At the consensus meeting, 27 participants from key stakeholder groups selected seven outcomes for the core outcome set: pain/discomfort with activity, pain/discomfort with rest, fine hand use/dexterity, self-hygiene/personal care, return to usual work/job, range of motion, and patient satisfaction with outcome/result. Conclusion. This set of core outcome domains is recommended as a minimum to be reported in all clinical research on hand fractures and joint injuries in adults. While this establishes what to measure, future work will focus on determining how best to measure these outcomes. By adopting this patient-centred core outcome set, consistency and comparability of studies will be improved, aiding meta-analysis and strengthening the evidence base for management of these common and impactful injuries. Cite this article: Bone Jt Open 2023;4(2):87–95

Aims. The Oxford Shoulder Score (OSS) is a 12-item measure commonly used for the assessment of shoulder surgeries. This study explores whether computerized adaptive testing (CAT) provides a shortened, individually tailored questionnaire while maintaining test accuracy. Methods. A total of 16,238 preoperative OSS were available in the National Joint Registry (NJR) for England, Wales, Northern Ireland, the Isle of Man, and the States of Guernsey dataset (April 2012 to April 2022). Prior to CAT, the foundational item response theory (IRT) assumptions of unidimensionality, monotonicity, and local independence were established. CAT compared sequential item selection with stopping criteria set at standard error (SE) < 0.32 and SE < 0.45 (equivalent to reliability coefficients of 0.90 and 0.80) to full-length patient-reported outcome measure (PROM) precision. Results. Confirmatory factor analysis (CFA) for unidimensionality exhibited satisfactory fit with root mean square standardized residual (RSMSR) of 0.06 (cut-off ≤ 0.08) but not with comparative fit index (CFI) of 0.85 or Tucker-Lewis index (TLI) of 0.82 (cut-off > 0.90). Monotonicity, measured by H value, yielded 0.482, signifying good monotonic trends. Local independence was generally met, with Yen’s Q3 statistic > 0.2 for most items. The median item count for completing the CAT simulation with a SE of 0.32 was 3 (IQR 3 to 12), while for a SE of 0.45 it was 2 (IQR 2 to 6). This constituted only 25% and 16%, respectively, when compared to the 12-item full-length questionnaire. Conclusion. Calibrating IRT for the OSS has resulted in the development of an efficient and shortened CAT while maintaining accuracy and reliability. Through the reduction of redundant items and implementation of a standardized measurement scale, our study highlights a promising approach to alleviate time burden and potentially enhance compliance with these widely used outcome measures. Cite this article: Bone Joint Res 2024;13(8):392–400

Aims. It is not clear which type of casting provides the best initial treatment in adults with a distal radial fracture. Given that between 32% and 64% of adequately reduced fractures redisplace during immobilization in a cast, preventing redisplacement and a disabling malunion or secondary surgery is an aim of treatment. In this study, we investigated whether circumferential casting leads to fewer fracture redisplacements and better one-year outcomes compared to plaster splinting. Methods. In a pragmatic, open-label, multicentre, two-period cluster-randomized superiority trial, we compared these two types of casting. Recruitment took place in ten hospitals. Eligible patients aged ≥ 18 years with a displaced distal radial fracture, which was acceptably aligned after closed reduction, were included. The primary outcome measure was the rate of redisplacement within five weeks of immobilization. Secondary outcomes were the rate of complaints relating to the cast, clinical outcomes at three months, patient-reported outcome measures (PROMs) (using the numerical rating scale (NRS), the abbreviated version of the Disabilities of the Arm, Shoulder and Hand (QuickDASH), and Patient-Rated Wrist/Hand Evaluation (PRWHE) scores), and adverse events such as the development of compartment syndrome during one year of follow-up. We used multivariable mixed-effects logistic regression for the analysis of the primary outcome measure. Results. The study included 420 patients. There was no significant difference between the rate of redisplacement of the fracture between the groups: 47% (n = 88) for those treated with a plaster splint and 49% (n = 90) for those treated with a circumferential cast (odds ratio 1.05 (95% confidence interval (CI) 0.65 to 1.70); p = 0.854). Patients treated in a plaster splint reported significantly more pain than those treated with a circumferential cast, during the first week of treatment (estimated mean NRS 4.7 (95% CI 4.3 to 5.1) vs 4.1 (95% CI 3.7 to 4.4); p = 0.014). The rate of complaints relating to the cast, clinical outcomes and PROMs did not differ significantly between the groups (p > 0.05). Compartment syndrome did not occur. Conclusion. Circumferential casting did not result in a significantly different rate of redisplacement of the fracture compared with the use of a plaster splint. There were comparable outcomes in both groups. Cite this article: Bone Joint J 2024;106-B(7):696–704

Aims. To map the Oxford Knee Score (OKS) and High Activity Arthroplasty Score (HAAS) items to a common scale, and to investigate the psychometric properties of this new scale for the measurement of knee health. Methods. Patient-reported outcome measure (PROM) data measuring knee health were obtained from the NHS PROMs dataset and Total or Partial Knee Arthroplasty Trial (TOPKAT). Assumptions for common scale modelling were tested. A graded response model (fitted to OKS item responses in the NHS PROMs dataset) was used as an anchor to calibrate paired HAAS items from the TOPKAT dataset. Information curves for the combined OKS-HAAS model were plotted. Bland-Altman analysis was used to compare common scale scores derived from OKS and HAAS items. A conversion table was developed to map between HAAS, OKS, and the common scale. Results. We included 3,329 response sets from 528 patients undergoing knee arthroplasty. These generally met the assumptions of unidimensionality, monotonicity, local independence, and measurement invariance. The HAAS items provided more information than OKS items at high levels of knee health. Combining both instruments resulted in higher test-level information than either instrument alone. The mean error between common scale scores derived from the OKS and HAAS was 0.29 logits. Conclusion. The common scale allowed more precise measurement of knee health than use of either the OKS or HAAS individually. These techniques for mapping PROM instruments may be useful for the standardization of outcome reporting, and pooling results across studies that use either PROM in individual-patient meta-analysis. Cite this article: Bone Joint Res 2023;12(10):624–635

Aims. The aim of this study was to compare the functional and radiological outcomes and the complication rate after nail and plate fixation of unstable fractures of the ankle in elderly patients. Methods. In this multicentre study, 120 patients aged ≥ 60 years with an acute unstable AO/OTA type 44-B fracture of the ankle were randomized to fixation with either a nail or a plate and followed for 24 months after surgery. The primary outcome measure was the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot score. Secondary outcome measures were the Manchester-Oxford Foot Questionnaire, the Olerud and Molander Ankle score, the EuroQol five-dimension questionnaire, a visual analogue score for pain, complications, the quality of reduction of the fracture, nonunion, and the development of osteoarthritis. Results. At 24 months, the median AOFAS score was equivalent in the two groups (nail 90 (interquartile range (IQR) 82 to 100), plate 95 (IQR 87 to 100), p = 0.478). There were statistically more complications and secondary operations after nail than plate fixation (p = 0.024 and p = 0.028, respectively). There were no other significant differences in the outcomes between the two groups. Conclusion. The functional outcome after nail and plate fixation was equivalent; however, the complication rate and number of secondary operations was significantly higher after nail fixation. These results suggest that plate fixation should usually be the treatment of choice for unstable ankle fractures in the elderly. Cite this article: Bone Joint J 2023;105-B(1):72–81

Aims. Leg length discrepancy (LLD) is a common pre- and postoperative issue in total hip arthroplasty (THA) patients. The conventional technique for measuring LLD has historically been on a non-weightbearing anteroposterior pelvic radiograph; however, this does not capture many potential sources of LLD. The aim of this study was to determine if long-limb EOS radiology can provide a more reproducible and holistic measurement of LLD. Methods. In all, 93 patients who underwent a THA received a standardized preoperative EOS scan, anteroposterior (AP) radiograph, and clinical LLD assessment. Overall, 13 measurements were taken along both anatomical and functional axes and measured twice by an orthopaedic fellow and surgical planning engineer to calculate intraoperator reproducibility and correlations between measurements. Results. Strong correlations were observed for all EOS measurements (r. s. > 0.9). The strongest correlation with AP radiograph (inter-teardrop line) was observed for functional-ASIS-to-floor (functional) (r. s. = 0.57), much weaker than the correlations between EOS measurements. ASIS-to-ankle measurements exhibited a high correlation to other linear measurements and the highest ICC (r. s. = 0.97). Using anterior superior iliac spine (ASIS)-to-ankle, 33% of patients had an absolute LLD of greater than 10 mm, which was statistically different from the inter-teardrop LLD measurement (p < 0.005). Discussion. We found that the conventional measurement of LLD on AP pelvic radiograph does not correlate well with long leg measurements and may not provide a true appreciation of LLD. ASIS-to-ankle demonstrated improved detection of potential LLD than other EOS and radiograph measurements. Full length, functional imaging methods may become the new gold standard to measure LLD. Cite this article: Bone Jt Open 2022;3(12):960–968

Aims. Radiostereometric analysis (RSA) is the most accurate radiological method to measure in vivo wear of highly cross-linked polyethylene (XLPE) acetabular components. We have previously reported very low wear rates for a sequentially irradiated and annealed X3 XLPE liner (Stryker Orthopaedics, USA) when used in conjunction with a 32 mm femoral heads at ten-year follow-up. Only two studies have reported the long-term wear rate of X3 liners used in conjunction with larger heads using plain radiographs which have poor sensitivity. The aim of this study was to measure the ten-year wear of thin X3 XLPE liners against larger 36 or 40 mm articulations with RSA. Methods. We prospectively reviewed 19 patients who underwent primary cementless THA with the XLPE acetabular liner (X3) and a 36 or 40 mm femoral head with a resultant liner thickness of at least 5.8 mm. RSA radiographs at one week, six months, and one, two, five, and ten years postoperatively and femoral head penetration within the acetabular component were measured with UmRSA software. Of the initial 19 patients, 12 were available at the ten-year time point. Results. The median proximal, 2D, and 3D wear rates calculated between one and ten years were all less than 0.005 mm/year, with no patient recording a proximal wear rate of more than 0.021 mm/year. Importantly, there was no increase in the wear rate between five and ten years. Conclusion. The very low wear rate of X3 XLPE liners with larger articulations remains encouraging for the future clinical performance of this material. Cite this article: Bone Jt Open 2023;4(11):839–845

Aims. Chronic osteomyelitis (COM) of the lower limb in adults can be surgically managed by either limb reconstruction or amputation. This scoping review aims to map the outcomes used in studies surgically managing COM in order to aid future development of a core outcome set. Methods. A total of 11 databases were searched. A subset of studies published between 1 October 2020 and 1 January 2011 from a larger review mapping research on limb reconstruction and limb amputation for the management of lower limb COM were eligible. All outcomes were extracted and recorded verbatim. Outcomes were grouped and categorized as per the revised Williamson and Clarke taxonomy. Results. A total of 3,303 records were screened, of which 99 studies were included. Most studies were case series (77/99; 78%) and assessed one method of reconstruction (68/99; 69%). A total of 511 outcomes were reported, which were grouped into 58 distinct outcomes. Overall, 143/511 of all outcomes (28%) were provided with a clear, in-text definition, and 231 outcomes (45%) had details reported of how and when they were measured. The most commonly reported outcome was ‘recurrence of osteomyelitis’ (62; 12%). The single-most patient-reported outcome measure was ‘pain’. Conclusion. This study has highlighted significant inconsistencies in the defining, reporting, and measuring of outcomes across studies investigating surgical management for chronic osteomyelitis of the lower limb in adults. Future studies should clearly report complete details of how outcomes are defined and measured, including timing. The development of a standardized core outcome set would be of significant benefit in order to allow evidence synthesis and comparison across studies. Cite this article: Bone Jt Open 2023;4(3):146–157

Aims. Refobacin Bone Cement R and Palacos R + G bone cement were introduced to replace the original cement Refobacin Palacos R in 2005. Both cements were assumed to behave in a biomechanically similar fashion to the original cement. The primary aim of this study was to compare the migration of a polished triple-tapered femoral stem fixed with either Refobacin Bone Cement R or Palacos R + G bone cement. Repeated radiostereometric analysis was used to measure migration of the femoral head centre. The secondary aims were evaluation of cement mantle, stem positioning, and patient-reported outcome measures. Methods. Overall, 75 patients were included in the study and 71 were available at two years postoperatively. Prior to surgery, they were randomized to one of the three combinations studied: Palacos cement with use of the Optivac mixing system, Refobacin with use of the Optivac system, and Refobacin with use of the Optipac system. Cemented MS30 stems and cemented Exceed acetabular components were used in all hips. Postoperative radiographs were used to assess the quality of the cement mantle according to Barrack et al, and the position and migration of the femoral stem. Harris Hip Score, Oxford Hip Score, Forgotten Joint Score, and University of California, Los Angeles Activity Scale were collected. Results. Median distal migration (y-axis) at two years for the Refobacin-Optivac system was -0.79 mm (-2.01 to -0.09), for the Refobacin-Optipac system was -0.75 mm (-2.16 to 0.20), and for the Palacos-Optivac system was -1.01 mm (-4.31 to -0.29). No statistically significant differences were found between the groups. Secondary outcomes did not differ statistically between the groups at the two-year follow-up. Conclusion. At two years, we found no significant differences in distal migration or clinical outcomes between the three groups. Our data indicate that Refobacin Bone Cement R and Palacos R + G are comparable in terms of stable fixation and early clinical outcomes. Cite this article: Bone Joint J 2024;106-B(5):435–441

Aims. The Cartiva synthetic cartilage implant (SCI) entered mainstream use in the management of first metatarsophalangeal joint (MTPJ) arthritis following the positive results of large trials in 2016. Limited information is available on the longer-term outcomes of this implant within the literature, particularly when independent from the originator. This single-centre cohort study investigates the efficacy of the Cartiva SCI at up to five years. Methods. First MTPJ arthritis was radiologically graded according to the Hattrup and Johnson (HJ) classification. Preoperative and sequential postoperative patient-reported outcome measures (PROMs) were evaluated using the Manchester-Oxford Foot Questionnaire (MOXFQ), and the activities of daily living (ADL) sub-section of the Foot and Ankle Ability Measure (FAAM). Results. Patients were followed up for a mean of 66 months (SD 7.1). Of an initial 66 cases, 16 did not return PROM questionnaires. A total of six failures were noted, with survival of 82%. Overall, significant improvement in both objective scores (MOXFQ and FAAM ADL) was maintained versus preoperatively: 18.2 versus 58.0 (p > 0.001) and 86.2 versus 41.1 (p > 0.001), respectively. The improvement was noted to be less pronounced in males. Subjective scores had deteriorated since early follow-up, with an interval decrease in patient satisfaction from 89% to 68%. Furthermore, a subset of cases demonstrated clinically important interval deterioration in objective scores. However, no specific patient factors were found to be associated with outcomes following analysis. Conclusion. This study represents the longest-term independent follow-up in the literature. It shows reassuring mid-term efficacy of the Cartiva SCI with better-than-expected survival. However, deterioration in scores for a subset of patients and lower satisfaction may predict ongoing failure in this group of patients. Additionally, males were noted to have a lower degree of improvement in scores than females. As such, ongoing observation of the SCI to assess durability and survivability, and identify predictive factors, is key to improving patient selection. Cite this article: Bone Jt Open 2024;5(9):799–805

Aims. The Manchester-Oxford Foot Questionnaire (MOxFQ) is an anatomically specific patient-reported outcome measure (PROM) currently used to assess a wide variety of foot and ankle pathology. It consists of 16 items across three subscales measuring distinct but related traits: walking/standing ability, pain, and social interaction. It is the most used foot and ankle PROM in the UK. Initial MOxFQ validation involved analysis of 100 individuals undergoing hallux valgus surgery. This project aimed to establish whether an individual’s response to the MOxFQ varies with anatomical region of disease (measurement invariance), and to explore structural validity of the factor structure (subscale items) of the MOxFQ. Methods. This was a single-centre, prospective cohort study involving 6,637 patients (mean age 52 years (SD 17.79)) presenting with a wide range of foot and ankle pathologies between January 2013 and December 2021. To assess whether the MOxFQ responses vary by anatomical region of foot and ankle disease, we performed multigroup confirmatory factor analysis. To assess the structural validity of the subscale items, exploratory and confirmatory factor analyses were performed. Results. Measurement invariance by pathology was confirmed, suggesting the same model can be used across all foot and ankle anatomical regions. Exploratory factor analysis demonstrated a two- to three-factor model, and suggested that item 13 (inability to carry out work/everyday activities) and item 14 (inability to undertake social/recreational activities) loaded more positively onto the “walking/standing” subscale than their original “social interaction” subscale. Conclusion. This large cohort study supports the current widespread use of the MOxFQ across a broad range of foot and ankle pathologies. Our analyses found indications that could support alterations to the original factor structure (items 13 and 14 might be moved from the “social interaction” to the “walking/standing” subscale). However, this requires further work to confirm. Cite this article: Bone Joint J 2024;106-B(3):256–261