Ankle fusion (AF), a durable intervention for ankle arthritis, has been the management of choice but restricts mobility. Recently, total ankle replacement (TAR) has been offered to patients looking to maintain mobility. The aim was to compare the biomechanics of AF and TAR while walking on inverted and everted slopes which create a greater demand for complex foot mobility than level walking. A ten-camera motion detection setup captured trials as patients walked in both directions over a 5⁰ lateral slope with embedded force plates. Moments (Nm/Kg) across the knee and ankle were exported from Visual 3D in the sagittal and frontal plane, and data were reported as means with 95% confidence intervals. 15 patients were recruited (6 TAR, 9 AF). The median age, follow-up and BMI was 67 years, 4 years and 35.8 kg/m² in AF, and 73 years, 7 years and 28.1 kg/m² in TAR, respectively. During inverted slope walking (4 TAR, 7 AF), abduction moments across (i) the knee: TAR 0.38 (0.37–0.39) vs AF 0.37 (0.27–0.52) and (ii) the ankle: TAR 0.20 (0.13–0.27) vs AF 0.25 (0.18–0.32), and extension moments across (i) the knee: TAR 0.68 (0.38–0.97) vs AF 0.85 (0.69–1.01) and (ii) the ankle: TAR 1.46 (1.30–1.62) vs AF 1.30 (1.08–1.52). During everted walking (5 TAR, 7 AF), abduction moments across (i) the knee: TAR 0.41 (0.30–0.52) vs AF 0.46 (0.27–0.66) and (ii) the ankle: TAR 0.24 (0.11–0.38) vs AF 0.26 (0.18–0.33), and extension moments across (i) the knee: TAR 0.76 (0.54–0.99) vs AF 0.93 (0.72–1.14) and (ii) the ankle: TAR 1.39 (1.19–1.59) vs AF 1.26 (1.04–1.48). There were no differences in abduction moments during inverted or everted slope walking. However, patients with AF had increased extension moments across the knee, particularly on inverted slopes, suggesting that AF creates a greater demand for knee compensation than TAR

Aims

To systematically review qualitative studies of patients with distal tibia or ankle fracture, and explore their experience of injury and recovery.

Aims. The aim of this study was to evaluate the functional outcome in patients undergoing implant removal (IR) after fracture fixation below the level of the knee. Patients and Methods. All adult patients (18 to 75 years) undergoing IR after fracture fixation below the level of the knee between November 2014 and September 2016 were included as part of the WIFI (Wound Infections Following Implant Removal Below the Knee) trial, performed in 17 teaching hospitals and two university hospitals in The Netherlands. In this multicentre prospective cohort, the primary outcome was the difference in functional status before and after IR, measured by the Lower Extremity Functional Scale (LEFS), with a minimal clinically important difference of nine points. Results. A total of 179 patients were included with a median age of 50 years (interquartile range (IQR) 37 to 60), of whom 71 patients (39.7%) were male. With a median score of 60 before IR (IQR 45 to 72) and 66 after IR (IQR 51 to 76) on the LEFS, there was a statistically significant improvement in functional outcome (p < 0 .001). A total of 31 surgical site infections (17.3%) occurred. Conclusion. Although IR led to a statistically significant improvement of functional outcome, the minimal clinically important difference was not reached. In conclusion, this study shows that IR does not result in a clinically relevant improvement in functional outcome. These results, in combination with the high complication rate, highlight the importance of carefully reviewing the indication for IR. Cite this article: Bone Joint J 2019;101-B:447–453

Background. The current ‘gold standard’ method for enabling weightbearing during non-invasive lower limb immobilisation is to use a Patella Tendon-Bearing (PTB) or Sarmiento cast. The Beagle Böhler Walker™ is a non-invasive frame that fits onto a standard below knee plaster cast. It is designed to achieve a reduction in force across the foot and ankle. Our objective was to measure loading forces through the foot to examine how different types of casts affect load distribution. We aimed to determine whether the Beagle Böhler Walker™ is as effective or better, at reducing load distribution during full weightbearing. Methods. We applied force sensors to the 1st and 5th metatarsal heads and the plantar surface of the calcaneum of 14 healthy volunteers. Force measurements were taken without a cast applied and then with a Sarmiento Cast, a below knee cast, and a below knee cast with Böhler Walker™ fitted. Results. Compared to a standard below knee cast, the Böhler Walker™ reduced the mean peak force through the first metatarsal head by 58.9% (p < .0001); 73.1% through the fifth metatarsal head (p < .0001); and by 32.2% (p < .0001) through the calcaneum. The Sarmiento cast demonstrated a mean percentage reduction in peak force of 8.6% (P = .39) and 4.4% (P = .87) through the 1st and 5th metatarsal heads respectively, but increased the mean peak force by 5.9% (P = .54) through the calcaneum. Conclusions. Using a Böhler Walker™ frame applied to a below knee cast significantly reduces loadbearing through the foot compared to a Sarmiento cast or a standard below knee cast. Implications. This could mean early weightbearing is safer and better tolerated in patients with a wide variety of foot and ankle pathologies, which can in turn improve quality of life and reduce the incidence of immobility dependent morbidity

Introduction. The prevalence of symptomatic osteoarthritis (OA) in the knee is 11–11% compared to 3.4–4.4% in the ankle. In addition to this, 70% of ankle arthritis is post-traumatic while the vast majority of knee arthritis is primary OA. Several reports have previously implicated biochemical differences in extracellular matrix composition between these joint cartilages; however, it is unknown whether there is an inherent difference in their transcriptome and how this might affect their respective functionality under load, inflammatory environment etc. Therefore, we have analysed the transcriptome of ankle and knee cartilage chondrocytes to determine whether this could account for the lower prevalence and altered aetiology of ankle OA. Methods. Human full-depth articular cartilage was taken from the talar domes (n=5) and the femoral condyles (n=5) following surgical amputation. RNA was extracted and next generation sequencing (NGS) performed using the NextSeq®500 system. Statistical analysis was performed to identify differentially regulated genes (p adj < 0.05). Data was analysed using Integrated Pathway Analysis software and genes of interest validated by quantitative PCR. Results. 809 genes were differentially expressed in this NGS study: 781 genes were significantly up-regulated and 27 significantly down-regulated in ankle cartilage with respect to knee. Preliminary analysis has identified several pathways which are differentially regulated including ‘inflammation mediated by cytokines’, ‘glutamate receptor pathway, ‘heterotrimeric-G-protein signalling pathways’, ‘WNT signalling’ and ‘integrin signalling’. Discussion. This is the first report identifying genes that are differentially expressed in ankle cartilage compared to the knee. Validation is currently being performed to ascertain the importance of these gene changes and correlation with their protein expression in the different joints. An understanding of the inherent biological differences in the cartilage between these two joints will provide invaluable insight into why the ankle is relatively spared from primary OA and the majority of ankle arthritis occurs following trauma

Aim. To determine the effects of knee and ankle position on tendo Achilles (TA) gap distance in patients with acute rupture using ultrasound. Methods. Twenty seven patients with twenty-eight acute complete TA ruptures confirmed on ultrasound were recruited within a week of injury. The mean age at presentation was 42 years (range 23-80 years). Ultrasound measurements included location of the rupture and the gap distance between the superficial tendon edges with the ankle in neutral and knee extended. The gap distance was sequentially measured with the foot in maximum equinus and 0°, 30°, 60° and 90° of knee flexion. Results. The mean distance of the rupture from the enthesis was 52mm (range: 40-76mm). The mean gap distance with the ankle in neutral and knee extended was 11.4mm (95%CI: 9.9, 12.9). This reduced to 4.8mm (95%CI: 3.3, 6.4) when the foot was in maximum equinus, 3.8mm (95%CI: 2.5, 5.1) with 30° knee flexion, 2.6mm (95%CI: 1.7, 3.6) with 60° knee flexion and 1.5mm (95% CI: 0.8, 2.2) with 90° knee flexion. Expressing the reduction in gap distance with each successive position as a percentage of the gap distance with the knee extended and ankle in neutral revealed a mean reduction of 58.9%, 66.9%, 77.1% and 85.9% with maximum equinus and 0°, 30°, 60° and 90° of knee flexion respectively. The difference in gap distance between each of these positions was statistically significant (p<0.05). Discussion. Maximum equinus alone significantly reduces the gap distance in acute TA rupture. Increasing knee flexion demonstrates a lesser effect throughout the initial 90° arc suggesting apposition is encouraged by use of a below knee maximum equinus cast permitting full knee flexion

The National Joint Registry (NJR) was established in 2003, and was extended to include ankle arthroplasty on 1. st. April 2010, and shoulder and elbow arthroplasty in April 2012. The aim of this study was to evaluate the uptake of the NJR for ankle arthroplasty over its first 3 years. This is compared to the first 3 years of hip and knee data, and the first year of shoulder and elbow data. The methods of measuring compliance are also evaluated. NJR compliance is measured by comparing the number of procedures submitted to the NJR, against the number of levies raised through implant sales. This applies to all of the UK, and both independent and NHS providers. However, compliance can also be measured by comparing NJR submissions with data submitted to the Hospital Episode Statistics (HES) database. This only relates to NHS institutions in England. The NJR ankle data was compared to implant data, and adjusted to compare to HES data, to evaluate the different methods of measuring compliance. We also compared these figures with the first 3 years for hip and knee arthroplasties and the first year for shoulder and elbow arthroplasties. Results:. In 2011 there were 493 arthroplasties and the compliance was 64% against industry data. In 2012 there were 590 procedures with compliance improved to 77% against industry data. When adjusting NJR to compare with HES data, the compliance was 87% in 2012., with 507 ankle arthroplasties registered with the NJR and 582 on HES data. The reasons for this discrepancy are discussed. The specific difficulties of capturing ankle revisions are discussed, as some get revised to arthrodeses. The uptake is significantly higher than the first year for all other joints (shoulders 52%, hips 57%, knees 57%, and elbows 60%)

Autologous osteochondral transplantation (AOT) is an effective treatment for large Osteochondral Lesions of the Talus (OLT), however little is reported on an athletic population, who are likely to place higher demands on the reconstruction. The aim is to report the outcomes of large OLT (>150mm. 2. ) within an athletic population. The study population was limited to professional or amateur athletes (Tegner score >6) with an OLT of size 150mm. 2. or greater. The surgical intervention was AOT with a donor site from the lateral femoral condyle. Clinical outcomes at a minimum of 24 months included Return to Sport, VAS and FAOS Scores. In addition, graft incorporation was evaluated by MRI using MOCART scores at 12 months post-surgery. 38 athletes including 11 professional athletes were assessed. Mean follow-up was 46 months. Mean lesion size was 249mm. 2. 33 patients returned to sport at their previous level and one did not return to sport (mean return to play 8.2 months). Visual analogue scores improved from 4.53 pre-operatively to 0.63 post-operatively (p=0.002). FAOS Scores improved significantly in all domains (p< 0.001). Two patients developed knee donor site pain, and both had three osteochondral plugs harvested. Univariant analysis demonstrated no association between pre-operative patient or lesion characteristics and ability to return to sport. However, there was a strong correlation between MOCART scores and ability to return to sport (AUC=0.89). Our study suggests that AOT is a viable option in the management of large osteochondral talar defects in an athletic population, with favourable return to sport levels, patient satisfaction, and FAOS/VAS scores. The ability to return to sport is predicated upon good graft incorporation and further research is required to optimise this technique. Our data also suggests that patients should be aware of the increased risk of developing knee donor site pain when three osteochondral plugs are harvested

Background. Corrective fusion of a deformed / unstable Charcot neuroarthropathy (CN)of the midfoot and hindfoot is performed with the aim to prevent ulcers and maintain patient mobility. Methods. Between October 2007 and July 2018, 103 CN mid and hind foot corrections in 95 patients were performed. There were 34 hind-foot, 38 mid-foot and 31 combined hind and mid-foot surgeries. 83 feet had single stage corrections, whereas 20 required a staged operation. Results. Ninety-five patients were prospectively followed up. The mean patient age in our study was 57 years (21 – 85). Twenty-seven patients had type1 diabetes, 64 patients had type 2 and 4 patients had a neuropathy secondary to other conditions. Forty patients (42%) were offered a below knee amputation prior to attending our foot clinic. At a mean follow up of 56 months (12 – 140) we achieved 100% limb salvage with a 75% full bone fusion rate. There were 17 mortalities within our cohort at a mean period of 3 years. Ninety-seven percent (n=92) patients were mobilizing post-operatively in orthotic footwear. Fifty-two feet had pre-operative ulcers. Post-operatively 17 feet (16 patients) had persistent ulceration. Eight patients had ulcer resolution following further surgery and alteration of footwear, one patient has been listed for a below knee amputation for unstable non-union, whilst the remaining 7 patients have stable ulcers which are managed with dressings. Of the 26 feet (25 patients) with non-unions, 6 patients had revision fixation procedures whilst 8 patients required minor surgical procedures. The remaining 11 patients are stable non-unions who are asymptomatic and weight bearing. Other complications included a deep infection rate of 8% (n=7). Conclusion. We demonstrated a 100% limb salvage rate and an 83% success rate in ulcer resolution. We recommend this be done with the support of the multi-disciplinary team

Background. Charcot neuroarthropathy is a destructive disease characterized by progressive bony fragmentation as a result of the isolated or accumulative trauma in patients with decreased sensation that manifests as dislocation, periarticular fractures and instability. Although amputation can be a reasonable cost economic solution, many patients are willing to avoid that if possible. We explored here one of the salvage procedures. Methods. 23 patients with infected ulcerated unstable Charcot neuroarthropathy of the ankle were treated between 2012 and 2017. The mean age was 63.5 ±7.9 years; 16 males and 7 females. Aggressive open debridement of ulcers and joint surfaces, with talectomy in some cases, were performed followed by external fixation with an Ilizarov frame. The primary outcome was a stable plantigrade infection free foot and ankle that allows weight bearing in accommodative foot wear. Results. Limb salvage was achieved in 91.3% of cases at the end of a mean follow up time of 25 months (range: 19–32). Fifteen (71.4%) solid bony unions were evident clinically and radiographically, while 6 (28.5%) patients developed stable painless pseudoarthrosis. Two patients had below knee amputations due to uncontrolled infection. Conclusion. Aggressive debridement and arthrodesis with ring external fixation can be used successfully to salvage severely infected Charcot arthropathy of the ankle. Pin tract infection, delayed wound healing and stress fracture may complicate the procedure but can be easily managed. Amputation may be the last resort in uncontrolled infection

Background. The importance of total ankle replacement (TAR) implant orientation in the axial plane is poorly understood with major variation in surgical technique of implants on the market. Our aims were to better understand the axial rotational profile of patients undergoing TAR. Methods. In 157 standardised CT Scans of end-stage ankle arthritis patients planning to undergo primary TAR surgery, we measured the relationship between the knee posterior condylar axis, the tibial tuberosity, the transmalleolar axis(TMA) and the tibiotalar angle. The foot position was measured in relation to the TMA with the foot plantigrade. The variation between medial gutter line and the line bisecting both gutters was assessed. Results. The mean external tibial torsion was 34.5±10.3°(11.8–62°). When plantigrade the mean foot position relative to the TMA was 21±10.6°(0.7–38.4°) internally rotated. As external tibial torsion increased, the foot position became more internally rotated relative to the TMA(pearson correlation 0.6;p< 0.0001). As the tibiotalar angle became more valgus, the foot became more externally rotated relative to the TMA(pearson correlation −0.4;p< 0.01). The mean difference between the medial gutter line and a line bisecting both gutters was 4.9±2.8°(1.7°-9.4°). More than 51% of patients had a difference greater than 5°. The mean angle between the medial gutter line and a line perpendicular to the TMA was 7.5°±2.6°(2.8°-13.7°). Conclusion. There is a large variation in rotational profile of patients undergoing TAR, particularly between the medial gutter line and the transmalleolar axis. Surgeon designers and implant manufacturers need to develop consistent methods to guide surgeons towards judging appropriate axial rotation of their implanton an individual basis. We recommend careful clinical assessment and CT scanspre-operatively to enable the correct rotation to be determined

Introduction. Severe, multiplanar, fixed, pantalar deformities present a challenge to orthopaedic surgeons. Surgical options include limb salvage or amputation. This study compares outcomes of patients with such deformities undergoing limb preservation with either pantalar fusion (PTF) or talectomy and tibiocalcaneal fusion (TCF), versus below knee amputation (BKA). Methods. Fifty-one patients undergoing either PTF, TCF and BKA for failed management of severe pantalar deformity were evaluated retrospectively. Twenty-seven patients underwent PTF, 8 TCF and 16 BKA. Median age at surgery was 55.0 years (17 to 72 years) and median follow-up duration was 49.9 months (18.0 to 253.7 months). Patients with chronic regional pain syndrome, tumour, acute trauma or diabetic Charcot arthropathy were excluded. Clinical evaluation was undertaken using the MOxFQ, EQ-5D and Special Interest Group in Amputee Medicine score (SIGAM). Patients were also asked whether they were satisfied with their surgical outcome and whether they would have the same surgery again. Results. There was no statistically significant difference in patient reported outcomes, satisfaction, or complication profile between the groups. Twenty-two patients undergoing PTF (81.5%), 6 patients undergoing TCF (75%), and 15 patients undergoing BKA (93.8%) were satisfied overall (p=0.414). Similarly, there was no difference in the proportion of patients who would opt for the same procedure again (p=0.142): 23 in the PTF group (85.2%), 8 in the TCF group (100%), and 11 in the BKA group (68.8%). Seven patients undergoing PTF (25.9%), 2 patients undergoing TCF (25%) and 6 patients undergoing BKA (37.5%) had major complications (p=0.692). Conclusion. This study has shown that PTF, TCF and BKA can all provide an acceptable outcome in treatment of severe, degenerative deformities of the lower extremity. Therefore, surgical decisions must be based on individual patient considerations. This data may also be useful in counselling patients when considering limb salvage versus amputation for severe deformity

Introduction. Lower limb immobilisation with full casts is commonly used to manage fractures. There may be the need to split casts in an emergency, such as compartment syndrome, with no current consensus as to which technique is most effective in reducing pressure quickly. Our study aims to compare the reduction in pressure across lower leg compartments using three different cast splitting techniques. Methods. This study was done on a volunteer doctor. Pressure sensors were positioned at the anterior, posterior and lateral compartments. A single plaster technician applied below knee full casts with sequential layering and were allowed to dry as per manufacture instructions. Cast were split utilising three splitting methods; bivalve, tramline and single split and measurements taken when each layer was split. We compared results of ten repetitions for each splitting technique. Results. When the cast was initially cut there were significant reduction in pressure with the bivalve split (20.6 ± 0.76 N) when compared to both the single split (26.8 ± 1.13 N, P < 0.001) and tramline split (26.4 ± 0.90 N, P < 0.001). When the cast was spread there were significant reduction in pressure with the bivalve split (10.7 ± 0.83 units) when compared to both the single split (14.6 ± 0.85 N, P < 0.001) and tramline split (16.6 ± 0.77 N, P < 0.001). When the final layer of wool was released the pressure remained lower (statistically significant) in the bivalve split compared to both single split and tramline split. Conclusion. Our study demonstrates that bivalve cast splitting provided a more rapid reduction in pressure compared to other techniques across all three compartments. Our data shows that once down to skin, bivalve splitting continues to provide the lowest pressure compared to the other techniques. We recommend utilising bivalve when splitting a cast in an emergency

Aims. Retrospective review of a consecutive series of 1,168 total ankle replacements (TAR) performed at Wrightington, to analyse modes of failure and clinical outcomes following TAR failure. Methods. All patients undergoing TAR between November 1993 – June 2019 were collated (4–25 year follow-up; mean 13.7 years). 6 implants were used (300 STAR, 100 Buechal Pappas, 509 Mobility, 118 Zenith, 41 Salto and 100 Infinity). 5 surgeons, all trained in TAR, performed the surgery. Modes of failure were collated and clinical and radiological outcomes recorded for the revisional surgery following failure of the TAR. Results. 156 (13.4%) TARs failed (47STAR 15.6%, 16BP 16%, 77Mobility 15.1%, 6Salto 14.6%, 10Zenith 8.5% and 0Infinity 0%). Mean time to failure 5.8 years (0.1- 21.4 years). The 4 most common modes of failure were 44.9% aseptic loosening, 11.5% gutter pain, 10.9% infection and 10.3% recurrent edge loading. 50 underwent conversion to tibiotalocalcaneal (TTC) fusion with nail with 9 (18%) failing to fuse. 31 underwent revision TAR with 2 (6.5%) subsequently failed. 22 underwent ankle fusion with 10 (45%) failing to fuse. 21 underwent polyethylene exchange of which 8 (38%) had further poly failure. 20 (12.8%) were managed conservatively, 2 (1.3%) required below knee amputation and 6 were listed but lost to follow-up. 81 of the 1168 (7%) consecutive cohort were lost to follow-up. Conclusions. 13.4% of the TAR cohort have failed at average follow-up 13.7 years. There was no difference in failure modes across the implant designs. Whilst the fixed bearing has the shortest follow-up, it may be performing better as there have been no failures so far. Prior to October 2016, most revisions were to fusion (TTC 18% failure rate, ankle 45% failure rate), whereas post 2016, 57% patients elected for revision TAR (6.5% failure)

Background. Calcaneal osteomyelitis remains a difficult condition to treat with high rates of recurrence and below knee amputation; particularly in cases of severe soft tissue destruction. Aim. Assess the outcomes of combined ortho-plastics treatment of complex calcaneal osteomyelitis. Method. A retrospective review was performed of all patients who underwent combined single stage ortho-plastics treatment of calcaneal osteomyelitis (2008–2022). Primary outcome measures were osteomyelitis recurrence and BKA. Secondary outcome measures included flap failure, operative time, complications, length of stay. Results. 33 patients (16 female, 17 male, mean age = 54.4 years) underwent combined ortho-plastics surgical treatment for BACH “complex” calcaneal osteomyelitis with a median follow-up of 31 months (s.d. 24.3). 20 received a local flap, 13 received a free flap. Fracture-related infection (39%) and diabetic ulceration (33%) were the commonest causes. 54% of patients had already undergone at least one operation elsewhere. There were seven cases of recurrent osteomyelitis (21%); all in the local flap group. One patient required a BKA (3%). Recurrence was associated with increased mortality risk (OR 18.8 (95% CI 1.5–227.8), p=0.004) and reduced likelihood of walking independently (OR 0.14 (95% CI 0.02–0.86), p=0.042). Local flap reconstruction (OR 15 (95% CI 0.8–289.6), p=0.027) and peripheral vascular disease (OR 39.7 (95% CI 1.7–905.6), p=0.006) were associated with increased recurrence risk. Free flap reconstruction took significantly longer intra-operatively than local flaps (443 vs 174 minutes, p<0.001), but without significant differences in length of stay or frequency of out-patient appointments. Conclusions. Single stage ortho-plastic management was associated with 79% eradication of infection and 3% amputation in this complex and co-morbid patient group. Risk factors for failure were peripheral vascular disease and local flap reconstruction. Whilst good outcomes can be achieved, this treatment requires high levels of in-patient and out-patient care

Aims

Venous thromboembolism (VTE) is a potential complication of foot and ankle surgery. There is a lack of agreement on contributing risk factors and chemical prophylaxis requirements. The primary outcome of this study was to analyze the 90-day incidence of symptomatic VTE and VTE-related mortality in patients undergoing foot and ankle surgery and Achilles tendon (TA) rupture. Secondary aims were to assess the variation in the provision of chemical prophylaxis and risk factors for VTE.

Aims

Osteochondral lesions of the talus (OLT) are a common cause of disability and chronic ankle pain. Many operative treatment strategies have been introduced; however, they have their own disadvantages. Recently lesion repair using autologous cartilage chip has emerged therefore we investigated the efficacy of particulated autologous cartilage transplantation (PACT) in OLT.

Aims

Arthroscopic microfracture is a conventional form of treatment for patients with osteochondritis of the talus, involving an area of < 1.5 cm². However, some patients have persistent pain and limitation of movement in the early postoperative period. No studies have investigated the combined treatment of microfracture and shortwave treatment in these patients. The aim of this prospective single-centre, randomized, double-blind, placebo-controlled trial was to compare the outcome in patients treated with arthroscopic microfracture combined with radial extracorporeal shockwave therapy (rESWT) and arthroscopic microfracture alone, in patients with ostechondritis of the talus.

Aims

A local injection may be used as an early option in the treatment of Morton’s neuroma, and can be performed using various medications. The aim of this study was to compare the effects of injections of hyaluronic acid compared with corticosteroid in the treatment of this condition.

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.