Aims. Functional rehabilitation has become an increasingly popular treatment for Achilles tendon rupture (ATR), providing comparably low re-rupture rates to surgery, while avoiding risks of surgical complications. Limited evidence exists on whether gap size should affect patient selection for this treatment option. The aim of this study was to assess if size of gap between ruptured tendon ends affects patient-reported outcome following ATR treated with functional rehabilitation. Methods. Analysis of prospectively collected data on all 131 patients diagnosed with ATR at Royal Berkshire Hospital, UK, from August 2016 to January 2019 and managed non-operatively was performed. Diagnosis was confirmed on all patients by dynamic ultrasound scanning and gap size measured with ankle in full plantarflexion. Functional rehabilitation using an established protocol was the preferred treatment. All non-operatively treated patients with completed Achilles Tendon Rupture Scores (ATRS) at a minimum of 12 months following injury were included. Results. In all, 82 patients with completed ATRS were included in the analysis. Their mean age was 51 years (standard deviation (SD) 14). The mean ATRS was 76 (SD 19) at a mean follow-up of 20 months (SD 11) following injury. Gap inversely affected ATRS with a Pearson’s correlation of -0.30 (p = 0.008). Mean ATRS was lower with gaps > 5 mm compared with ≤ 5 mm (73 (SD 21) vs 82 (SD 16); p = 0.031). Mean ATRS was lowest (70 (SD 23)) with gaps > 10 mm, with significant differences in perceived strength and pain. The overall re-rupture rate was two out of 131 (1.5%). Conclusion. Increasing gap size predicts lower patient-reported outcome, as measured by ATRS. Tendon gap > 5 mm may be a useful predictor in physically demanding individuals, and tendon gap > 10 mm for those with low physical demand. Further studies that control for gap size when comparing non-operative and operative treatment are required to assess if these patients may benefit from surgery, particularly when balanced against the surgical risks. Cite this article: Bone Joint J 2020;102-B(11):1535–1541

Aims. The aim was to compare long-term patient-reported outcome measures (PROMs) after operative and nonoperative treatment of acute Achilles tendon rupture in the context of a randomized controlled trial. Methods. PROMs including the Short Musculoskeletal Function Assessment (SMFA), Achilles Tendon Total Rupture Score (ATRS), EuroQol five-dimension (EQ-5D), satisfaction, net promoter score and data regarding re-rupture, and venous thromboembolic rates were collected for patients randomized to receive either operative or nonoperative treatment for acute Achilles tendon rupture in a previous study. Of the 80 patients originally randomized, 64 (33 treated surgically, 31 nonoperatively) patients were followed up at a mean of 15.7 years (13.4 to 17.7). Results. There was no statistically significant difference between operatively and nonoperatively treated patients, in SMFA Dysfunction Index (median 1.56 (interquartile range (IQR) 0 to 5.51) vs 1.47 (IQR 0 to 5.15); p = 0.289), SMFA Bother Index (2.08 (IQR 0 to 12.50) vs 0.00 (IQR 0 to 6.25); p = 0.074), ATRS (94 (IQR 86 to 100) vs 95 (IQR 81 to 100); p = 0.313), EQ-5D-5L (1 (IQR 0.75 to 1) vs 1 (IQR 0.84 to 1); p = 0.137) or EQ-5D health today visual analogue score (85 (IQR 72.5 to 95) vs 85 (IQR 8 to 95); p = 0.367). There was no statistically significant difference between operative and nonoperative groups in terms of satisfaction (84% vs 100%; p = 0.119) or willingness to recommend treatment to friends or family (79% vs 87%; p = 0.255). Four nonoperative patients and two in the operative group sustained a re-rupture (p = 0.306). Conclusion. Both patient groups reported good results at long-term follow-up. The findings give no evidence of superior long-term patient reported outcomes (as measured by the SMFA) for surgical treatment over nonoperative treatment. There was no demonstrable difference in other patient reported outcome measures, satisfaction, or re-rupture rates at long-term follow-up. Cite this article: Bone Joint J 2020;102-B(7):933–940

Aims

This is a multicentre, non-inventor, prospective observational study of 503 INFINITY fixed bearing total ankle arthroplasties (TAAs). We report our early experience, complications, and radiological and functional outcomes.

Introduction

The aim of this study was to identify the effects of first MTPJ arthritis, ankle arthritis and hallux valgus on patient reported outcomes, and to assess the efficacy of surgery.

The outcome in 83 patients with congenital clubfoot was evaluated at a mean age of 64 years using three validated questionnaires assessing both quality of life (short-form (SF)-36 and EQ-5D) and foot and ankle function (American Academy of Orthopaedic Surgeons (AAOS) Foot and Ankle questionnaire). In SF-36, male patients scored significantly better than male norms in seven of the eight domains, whereas female patients scored significantly worse than female norms in two of the eight. Male patients scored better than male norms in both the EQ-5D index (p = 0.027) and visual analogue scale (VAS) (p = 0.013), whereas female patients scored worse than female norms in the VAS (p < 0.001). Both male and female patients had a significantly worse outcome on the AAOS Core Scale than did norms. There was a significant correlation for both genders between the SF-36 Physical Component Summary Score and the AAOS Core Scale.

The influence on activities of daily life was limited to foot and ankle problems in all patients, and in females there was an adverse effect in physical aspects of quality of life.

Aim

To examine the mid-term survival, clinical and patient reported outcomes of the silastic 1^st metatarsophalangeal joint replacement for the treatment of end stage hallux rigidus.

Aims. This scoping review aims to identify patient-related factors associated with a poorer outcome following total ankle arthroplasty (TAA). Methods. A scoping review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A computer-based literature search was performed in PubMed, Embase, Cochrane trials, and Web of Science. Two reviewers independently performed title/abstract and full-text screening according to predetermined selection criteria. English-language original research studies reporting patient-related factors associated with a poorer outcome following TAA were included. Outcomes were defined as patient-reported outcome measures (PROMs), perioperative complications, and failure. Results. A total of 94 studies reporting 101,552 cases of TAA in 101,177 patients were included. The most common patient-related risk factor associated with poorer outcomes were younger age (21 studies), rheumatoid arthritis (17 studies), and diabetes (16 studies). Of the studies using multivariable regression specifically, the most frequently described risk factors were younger age (12 studies), rheumatoid arthritis (eight studies), diabetes (eight studies), and high BMI (eight studies). Conclusion. When controlling for confounding factors, the most commonly reported risk factors for poor outcome are younger age, rheumatoid arthritis, and comorbidities such as diabetes and increased BMI. These patient-related risk factors reported may be used to facilitate the refinement of patient selection criteria for TAA and inform patient expectations. Cite this article: Bone Joint J 2023;105-B(9):985–992

Aims. Although absorbable sutures for the repair of acute Achilles tendon rupture (ATR) have been attracting attention, the rationale for their use remains insufficient. This study prospectively compared the outcomes of absorbable and nonabsorbable sutures for the repair of acute ATR. Methods. A total of 40 patients were randomly assigned to either braided absorbable polyglactin suture or braided nonabsorbable polyethylene terephthalate suture groups. ATR was then repaired using the Krackow suture method. At three and six months after surgery, the isokinetic muscle strength of ankle plantar flexion was measured using a computer-based Cybex dynamometer. At six and 12 months after surgery, patient-reported outcomes were measured using the Achilles tendon Total Rupture Score (ATRS), visual analogue scale for pain (VAS pain), and EuroQoL five-dimension health questionnaire (EQ-5D). Results. Overall, 37 patients completed 12 months of follow-up. No difference was observed between the two groups in terms of isokinetic plantar flexion strength, ATRS, VAS pain, or EQ-5D. No re-rupture was observed in either group. Conclusion. The use of absorbable sutures for the repair of acute ATR was not inferior to that of nonabsorbable sutures. This finding suggests that absorbable sutures can be considered for the repair of acute ATRs. Cite this article: Bone Joint J 2022;104-B(8):938–945

Aims. The Vantage Total Ankle System is a fourth-generation low-profile fixed-bearing implant that has been available since 2016. We aimed to describe our early experience with this implant. Methods. This is a single-centre retrospective review of patients who underwent primary total ankle arthroplasty (TAA) with a Vantage implant between November 2017 and February 2020, with a minimum of two years’ follow-up. Four surgeons contributed patients. The primary outcome was reoperation and revision rate of the Vantage implant at two years. Secondary outcomes included radiological alignment, peri-implant complications, and pre- and postoperative patient-reported outcomes. Results. There were 168 patients (171 ankles) included with a mean follow-up of 2.81 years (2 to 4.6) and mean age of 63.0 years (SD 9.4). Of the ten ankles with implant failure (5.8%), six had loosening of the tibial component. In the remaining four failed implants, one was due to periprosthetic joint infection (PJI), one was due to loosening of the talar component, and two were due to loosening of both the tibial and talar components. Seven patients underwent reoperation: irrigation and debridement for superficial infection (n = 4); bone grafting for cysts (n = 2); and open reduction internal fixation (n = 1). Asymptomatic peri-implant lucency/subsidence occurred in 20.1% of ankles, with the majority involving the tibial component (n = 25). There were statistically significant improvements in PROMs in all domains. Conclusion. Short-term results of this implant demonstrate early survival comparable to the reported survivorship of similar low-profile, non-stemmed implants. Radiological lucency occurred more commonly at the tibial component, and revisions occurred primarily due to loosening of the tibial component. Further research is needed to evaluate longer-term survivorship. Cite this article: Bone Joint J 2023;105-B(10):1099–1107

Aims. The aim of this study was to capture 12-month outcomes from a representative multicentre cohort of patients undergoing total ankle arthroplasty (TAA), describe the pattern of patient-reported outcome measures (PROMs) at 12 months, and identify predictors of these outcome measures. Methods. Patients listed for a primary TAA at 19 NHS hospitals between February 2016 and October 2017 were eligible. PROMs data were collected preoperatively and at six and 12 months including: Manchester-Oxford Foot and Ankle Questionnaire (MOXFQ (foot and ankle)) and the EuroQol five-dimension five-level questionnaire (EQ-5D-5L). Radiological pre- and postoperative data included Kellgren-Lawrence score and implant position measurement. This was supplemented by data from the National Joint Registry through record linkage to determine: American Society of Anesthesiologists (ASA) grade at index procedure; indication for surgery, index ankle previous fracture; tibial hind foot alignment; additional surgery at the time of TAA; and implant type. Multivariate regression models assessed outcomes, and the relationship between MOXFQ and EQ-5D-5L outcomes, with patient characteristics. Results. Data from 238 patients were analyzed. There were significant improvements in MOXFQ and EQ-5D-5L among people who underwent TAA at six- and 12-month assessments compared with preoperative scores (p < 0.001). Most improvement occurred between preoperative and six months, with little further improvement at 12 months. A greater improvement in MOXFQ outcome postoperatively was associated with older age and more advanced radiological signs of ankle osteoarthritis at baseline. Conclusion. TAA significantly benefits patients with end-stage ankle disease. The lack of substantial further overall change between six and 12 months suggests that capturing PROMs at six months is sufficient to assess the success of the procedure. Older patients and those with advanced radiological disease had the greater gains. These outcome predictors can be used to counsel younger patients and those with earlier ankle disease on the expectations of TAA. Cite this article: Bone Joint J 2023;105-B(8):895–904

Aims. Implant failure has become more common as the number of primary total ankle arthroplasties (TAAs) performed has increased. Although revision arthroplasty has gained attention for functional preservation, the long-term results remain unclear. This study aimed to assess the long-term outcomes of revision TAA using a mobile-bearing prosthesis in a considerably large cohort; the risk factors for failure were also determined. Methods. This single-centre retrospective cohort study included 116 patients (117 ankles) who underwent revision TAA for failed primary TAA between July 2000 and March 2010. Survival analysis and risk factor assessment were performed, and clinical performance and patient satisfaction were evaluated preoperatively and at last follow-up. Results. The mean duration from initial revision TAA to last follow-up was 15.0 years (SD 3.0; 11.2 to 20.5). The cumulative survival rates of the revised ankles were 81% (95% confidence interval (CI) 74% to 88%), 74% (65% to 82%), and 70% (61% to 79%) at five, ten, and 15 years, respectively. Comorbidities prior to primary TAA, aseptic loosening, instability, or grafting of cysts were found to be the most common risk factors for secondary revision. The median value for preoperative pain, as assessed using the visual analogue scale, declined from 6 (interquartile range (IQR) 5 to 8) to 2 (IQR 0 to 5) (p < 0.001) and the mean American Orthopaedic Foot and Ankle Society ankle-hindfoot score improved from 43 (SD 17) preoperatively to 70 (SD 20) (p < 0.001) at last follow-up. Conclusion. Revision TAA offers acceptable survival rates after 15 years; it therefore offers a valuable option for treatment of implant failure in carefully selected cases. Although patient-reported outcomes improve substantially, the degree of improvement reported following primary TAA is not achieved. Cite this article: Bone Joint J 2024;106-B(1):46–52

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

Background. Patients who undergo either primary or revision total ankle replacement (TAR) expect improvements in pain, function and quality of life. The goal of this study was to measure the functional outcome improvements and the difference in patient-reported outcomes in patients undergoing primary total ankle replacements compared to revision TAR. Methods. A single-center prospective cohort study was undertaken between 2016 and 2022. All patients were followed up for a minimum of 6 months. Patients undertook the Manchester Oxford Foot Questionnaire (MoxFQ) and EQ-5D health quality questionnaires pre-operatively, at 6 months and yearly for life. The Mann Whitney test was undertaken for statistical analysis. Results. A total of 165 primary and 71 revision ankle replacements were performed between 2016 and 2022. The mean age was 71 years for primary replacements and 69 years for revisions. The INFINITY was utilized in the majority of primary total ankle replacements. Revision replacements were either the INBONE II or INVISION and they were most often revising the MOBILITY implant. The main indication for revision was aseptic loosening (83%). Other causes included infection, malalignment and insert wear. The overall MoxFQ improved by a mean of 46.5 for primaries and 40.2 for revisions. The EQ-5D score also showed overall improvements with the mean difference in mobility increasing by 1.6. Conclusion. Both primary and revision ankle replacements result in improved functional scores at 6 months, 1 year and 2 years. In this cohort with the implants used, both primary and revision ankle replacements demonstrate similar improvements in functional scores

Background. Infiltration is considered the first treatment option for symptomatic Morton's neuroma and can be performed with various medications. The aim of this study was to compare the effects of hyaluronic acid infiltration versus corticosteroid injection in the treatment of Morton's neuroma. Methods. A randomised clinical trial was conducted with 46 patients (50 feet) diagnosed with Morton's neuroma. After randomisation, the control group (CG) received three injections (one per week) of triamcinolone (Triancil®) guided by ultrasound, while the study group (SG) received three applications of hyaluronic acid (Osteonil Plus®). Patients were followed up for six months after the intervention. The primary outcome measure used was the Visual Pain Analog Scale (VAS). Secondary endpoints included patient-reported outcome measures using the American Orthopaedic Foot & Ankle Society (AOFAS) score and complications. Results. Both groups showed significant improvement in VAS and AOFAS scores (p < 0.001). The CG showed greater improvement than the SG in the VAS (p < 0.05) and AOFAS (p < 0.001) variables. Four patients in the CG experienced skin hypochromia at the injection site, while there were no complications in the SG. Conclusion. Ultrasound-guided hyaluronic acid infiltration in Morton's Neuroma proved to be safe, showing improvement in pain and function after six months of follow-up, without major complications, but with a significantly lower improvement when compared to corticosteroid injection. Taking into account cost implications and the potential for longer lasting improvement from viscosupplementation further medium- and long-term studies are needed

Objectives. Cartiva synthetic cartilage implant (SCI) is licenced for use in management of symptomatic hallux rigidus in several countries including the UK. As for now, there are no independent comparative series for treatment of hallux rigidus utilising polyvinyl alcohol implants. Study design and methods. Patients at a single centre with symptomatic hallux rigidus who underwent Cartiva SCI implant procedure were identified. First metatarsophalangeal joint arthritis was radiographically graded according to the Hattrup and Johnson (HJ) classification. Pre-operative and post-operative patient-reported outcomes were evaluated using the Foot and Ankle Ability Measure (FAAM) activities of daily living subscale and the Manchester-Oxford Foot Questionnaire (MOXFQ). Results. 66 patients (19M, 47F) (43R and 23L) were followed up for an average of 14 months (min=2, max=36). 17 patients suffered from HJ2/moderate arthritis and 49 patients with grade HJ3/severe arthritis. Post-operative mean FAAM scores showed statistically significant improvement (p< 0.0001). Patients reported a 40% increase in functionality during activities of daily living. All 3 MOXFQ Domain scores improved significantly (p< 0.02). The Index score improved by 28 points (p< 0.0001). There was no correlation between length of follow up or age and PROMs (r=0.129). No statistical difference was demonstrated between sexes. However clinically, males and older patients exhibit better outcomes. There was a 89.4% patient satisfaction with the use of Cartiva. Conclusions. Our study shows excellent results with statistically significant improvements in functional outcomes, and promising short-term follow-up with low early revision rates. Pain in particular was significantly reduced. One third of patients developed post-operative stiffness requiring a manipulation under anaesthesia. Patient selection is key. Additional imaging may be required to assess sesamoid osteoarthritis. At 3 years the implant has demonstrated to be safe and efficacious in the management of hallux rigidus. Durability and survivability of the implant will continue to be studied in this cohort

Aims. We report the medium-term outcomes of a consecutive series of 118 Zenith total ankle arthroplasties (TAAs) from a single, non-designer centre. Methods. Between December 2010 and May 2016, 118 consecutive Zenith prostheses were implanted in 114 patients. Demographic, clinical, and patient-reported outcome measures (PROMs) data were collected. The endpoint of the study was failure of the implant requiring revision of one or all of the components. Kaplan-Meier survival curves were generated with 95% confidence intervals (CIs) and the rate of failure calculated for each year. Results. Eight patients (ten ankles) died during follow-up, but none required revision. Of the surviving 106 patients (108 ankles: rheumatoid arthritis (RA), n = 15; osteoarthritis (OA), n = 93), 38 were women and 68 were men, with a mean age of 68.2 years (48 to 86) at the time of surgery. Mean follow-up was 5.1 years (2.1 to 9.0). A total of ten implants failed (8.5%), thus requiring revision. The implant survival at seven years, using revision as an endpoint, was 88.2% (95% CI 100% to 72.9%). There was a mean improvement in Manchester-Oxford Foot and Ankle Questionnaire (MOXFQ) from 85.0 to 32.8 and visual analogue scale (VAS) scores from 7.0 to 3.2, and overall satisfaction was 89%. The three commonest complications were malleolar fracture (14.4%, n = 17), wound healing (13.6%, n = 16), and superficial infection (12.7%, n = 15). The commonest reason for revision was aseptic loosening. No patients in our study were revised for deep infection. Conclusion. Our results show that Zenith survival rates are comparable with those in the literature for other implants and in the National Joint Registry (NJR). Overall patient satisfaction was high as were functional outcomes. However, the data highlight potential complications associated with this surgery. The authors believe that these figures support ankle arthroplasty as an option in the treatment of ankle arthritis. Cite this article: Bone Joint J 2021;103-B(4):696–703

The effect of BMI on patient-reported outcomes following total ankle replacement (TAR) is uncertain and the change in BMI experienced by these patients in the 5 years following surgery has not been studied. We report a series of 106 patients with complete 5-year data on BMI and patient-reported outcome scores. Patients undergoing TAR between 2006 and 2009, took part in the hospital joint registry, which provides routine clinical audit of patient progress following total joint arthroplasty; therefore, ethics committee approval was not required for this study. Data on BMI, Foot and Ankle Score (FAOS) and SF-36 score were collected preoperatively and annually postoperatively. Patients who were obese (BMI >30) had lower FAOS scores pre-operatively and at 5 years, however this did not reach significance. Both obese (p = 0.0004) and non-obese (p < 0.0001) patients demonstrated a significant improvement in FAOS score from baseline to 5 years. This improvement was more marked for the non-obese patients. No significant differences were seen for SF36 scores between obese and non-obese patients either at baseline or 5 years. There was a trend for improved score in both groups. Mean pre-operative BMI was 28.49. Mean post-operative BMI was 28.33. The mean difference between pre- and post-operative BMI was −0.15, which was not statistically significant (p=0.55). There were no significant differences in revisions in the obese (2) and non-obese (1 and one awaited) groups at 5 years. This data supports use of TAR in the obese population, as significant increases in mean FAOS score were seen in this group at 5 years. Obesity did not have a significant influence on patients' overall health perceptions, measured by the SF36 and a trend for improvement was seen in both obese and non-obese patients. TAR cannot be relied upon to result in significant post-operative weight-loss without further interventions

Aims . This is the first prospective study to report the pre- and post-operative patient reported outcomes and satisfaction scores following excision of interdigital Morton’s neuroma. Patients and Methods. Between May 2006 and April 2013, we prospectively studied 99 consecutive patients (111 feet) who were to undergo excision of a Morton’s neuroma. There were 78 women and 21 men with a mean age at the time of surgery of 56 years (22 to 78). Patients completed the Manchester-Oxford Foot Questionnaire (MOXFQ), Short Form-12 (SF-12) and a supplementary patient satisfaction survey three months pre-operatively and six months post-operatively. Results. Statistically significant differences were found between the mean pre- and post-operative MOXFQ and the physical component of the SF-12 scores (p = 0.00081 and p = 0.00092 respectively). Most patients reported their overall satisfaction as excellent (n = 49, 49.5%) or good (n = 29, 29.3%), but ten patients were dissatisfied, reporting poor (n = 8, 8.1%) or very poor (n = 2, 2.0%) results. Only 63 patients (63%) were pain-free at follow-up: in eight patients (8.1%), the MOXFQ score worsened. There was no statistically significant difference in outcome between surgery on single or multiple sites. However, the MOXFQ scores were significantly worse after revision surgery (p = 0.004). Conclusions. The patient-reported outcomes after resection of a symptomatic Morton’s neuroma are acceptable but may not be as good as earlier studies suggest. Surgery at several sites can be undertaken safely but caution should be exercised when considering revision surgery. Cite this article: Bone Joint J 2016;98-B:1376–81

Aims. This prospective cohort study aims to determine if the size of the tendon gap following acute rupture of the Achilles tendon shows an association with the functional outcome following non-operative treatment. . Patients and Methods. All patients presenting within two weeks of an acute unilateral rupture of the Achilles tendon between July 2012 and July 2015 were considered for the study. In total, 38 patients (nine female, 29 male, mean age 52 years; 29 to 78) completed the study. Dynamic ultrasound examination was performed to confirm the diagnosis and measure the gap between ruptured tendon ends. Outcome was assessed using dynamometric testing of plantarflexion and the Achilles tendon Total Rupture score (ATRS) six months after the completion of a rehabilitation programme. Results. Patients with a gap ≥ 10 mm with the ankle in the neutral position had significantly greater peak torque deficit than those with gaps < 10 mm (mean 23.3%; 7% to 52% vs 14.3%; 0% to 47%, p = 0.023). However, there was no difference in ATRS between the two groups (mean score 87.2; 74 to 100 vs 87.4; 68 to 97, p = 0.467). There was no significant correlation between gap size and torque deficit (τ = 0.103), suggesting a non-linear relationship. There was also no significant correlation between ATRS and peak torque deficit (τ = -0.305). . Conclusion . This is the first study to identify an association between tendon gap and functional outcome in acute rupture of the Achilles tendon. We have identified 10 mm as a gap size at which deficits in plantarflexion strength become significantly greater, however, the precise relationship between gap size and plantarflexion strength remains unclear. Large, multicentre studies will be needed to clarify this relationship and identify population subgroups in whom deficits in peak torque are reflected in patient-reported outcome measures. . Cite this article: Bone Joint J 2017;99-B:87–93

Aims

The rationale for exacting restoration of skeletal anatomy after unstable ankle fracture is to improve outcomes by reducing complications from malunion; however, current definitions of malunion lack confirmatory clinical evidence.