Aims. Various radiological parameters are used to evaluate a flatfoot deformity and their measurements may differ. The aims of this study were to answer the following questions: 1) Which of the 11 parameters have the best inter- and intraobserver reliability in a standardized radiological setting? 2) Are pre- and postoperative assessments equally reliable? 3) What are the identifiable sources of variation?. Patients and Methods. Measurements of the 11 parameters were recorded on anteroposterior and lateral weight-bearing radiographs of 38 feet before and after surgery for flatfoot, by three observers with different experience in foot surgery (A, ten years; B, three years; C, third-year orthopaedic resident). The inter- and intraobserver reliability was calculated. Results. Preoperative interobserver reliability was high for four, moderate for five, and low for two parameters. Postoperative interobserver reliability was high for four, moderate for five, and low for two parameters. Intraobserver reliability was excellent for all parameters preoperatively as recorded by observer A (PB) and B (MP), and for eight parameters as recorded by observer C (SR). Intraobserver reliability was excellent for ten parameters postoperatively as recorded by observer A and B, and for eight parameters as recorded by observer C. Conclusion. The following parameters can be recommended. For preoperative and postoperative evaluation of flatfoot: anteroposterior, talonavicular coverage angle; lateral, talometatarsal I angle, calcaneal pitch angle, and cuneiform-medial height (high interobserver reliability); and anteroposterior, talometatarsal II angle; lateral, talocalcaneal angle,tibiocalcaneal angle (moderate interobserver reliability). For more experienced observers, we also recommend the anteroposterior talometatarsal I angle (moderate reliability). The inter- and intraobserver reliability for most parameters were similar pre- and postoperatively. The experience of the observer and the definition and ability to measure the parameters themselves were sources of variation. Cite this article: Bone Joint J 2018;100-B:596–602

Aims. The Chopart joint complex is a joint between the midfoot and hindfoot. The static and dynamic support system of the joint is critical for maintaining the medial longitudinal arch of the foot. Any dysfunction leads to progressive collapsing flatfoot deformity (PCFD). Often, the tibialis posterior is the primary cause; however, contrary views have also been expressed. The present investigation intends to explore the comprehensive anatomy of the support system of the Chopart joint complex to gain insight into the cause of PCFD. Methods. The study was conducted on 40 adult embalmed cadaveric lower limbs. Chopart joint complexes were dissected, and the structures supporting the joint inferiorly were observed and noted. Results. The articulating bones exhibit features like a cuboid shelf and navicular beak, which appear to offer inferior support to the joint. The expanse of the spring ligament complex is more medial than inferior, while the superomedial part is more extensive than the intermediate and inferoplantar parts. The spring ligament is reinforced by the tendons in the superomedial part (the main tendon of tibialis posterior), the inferomedial part (the plantar slip of tibialis posterior), and the master knot of Henry positioned just inferior to the gap between the inferomedial and inferoplantar bundles. Conclusion. This study highlights that the medial aspect of the talonavicular articulation has more extensive reinforcement in the form of superomedial part of spring ligament and tibialis posterior tendon. The findings are expected to prompt further research in weightbearing settings on the pathogenesis of flatfoot. Cite this article: Bone Jt Open 2024;5(4):335–342

Objective. The objective of this study was to evaluate the rotation and translation of each joint in the hindfoot and compare the load response in healthy feet with that in stage II posterior tibial tendon dysfunction (PTTD) flatfoot by analysing the reconstructive three-dimensional (3D) computed tomography (CT) image data during simulated weight-bearing. . Methods. CT scans of 15 healthy feet and 15 feet with stage II PTTD flatfoot were taken first in a non-weight-bearing condition, followed by a simulated full-body weight-bearing condition. The images of the hindfoot bones were reconstructed into 3D models. The ‘twice registration’ method in three planes was used to calculate the position of the talus relative to the calcaneus in the talocalcaneal joint, the navicular relative to the talus in talonavicular joint, and the cuboid relative to the calcaneus in the calcaneocuboid joint. Results. From non- to full-body-weight-bearing condition, the difference in the talus position relative to the calcaneus in the talocalcaneal joint was 0.6° more dorsiflexed (p = 0.032), 1.4° more everted (p = 0.026), 0.9 mm more anterior (p = 0.031) and 1.0 mm more proximal (p = 0.004) in stage II PTTD flatfoot compared with that in a healthy foot. The navicular position difference relative to the talus in the talonavicular joint was 3° more everted (p = 0.012), 1.3 mm more lateral (p = 0.024), 0.8 mm more anterior (p = 0.037) and 2.1 mm more proximal (p = 0.017). The cuboid position difference relative to the calcaneus in the calcaneocuboid joint did not change significantly in rotation and translation (all p ≥ 0.08). . Conclusion. Referring to a previous study regarding both the cadaveric foot and the live foot, joint instability occurred in the hindfoot in simulated weight-bearing condition in patients with stage II PTTD flatfoot. The method used in this study might be applied to clinical analysis of the aetiology and evolution of PTTD flatfoot, and may inform biomechanical analyses of the effects of foot surgery in the future. Cite this article: Bone Joint Res 2013;2:255–63

Talonavicular and subtalar joint fusion through a medial incision (modified triple arthrodesis) has become an increasingly popular technique for treating symptomatic flatfoot deformity caused by posterior tibial tendon dysfunction. The purpose of this study was to look at its clinical and radiological mid- to long-term outcomes, including the rates of recurrent flatfoot deformity, nonunion and avascular necrosis of the dome of the talus. A total of 84 patients (96 feet) with a symptomatic rigid flatfoot deformity caused by posterior tibial tendon dysfunction were treated using a modified triple arthrodesis. The mean age of the patients was 66 years (35 to 85) and the mean follow-up was 4.7 years (1 to 8.3). Both clinical and radiological outcomes were analysed retrospectively. In 86 of the 95 feet (90.5%) for which radiographs were available, there was no loss of correction at final follow-up. In all, 14 feet (14.7%) needed secondary surgery, six for nonunion, two for avascular necrosis, five for progression of the flatfoot deformity and tibiotalar arthritis and one because of symptomatic overcorrection. The mean American Orthopaedic Foot and Ankle Society Hindfoot score (AOFAS score) at final follow-up was 67 (between 16 and 100) and the mean visual analogue score for pain 2.4 points (between 0 and 10). In conclusion, modified triple arthrodesis provides reliable correction of deformity and a good clinical outcome at mid- to long-term follow-up, with nonunion as the most frequent complication. Avascular necrosis of the talus is a rare but serious complication of this technique. Cite this article: Bone Joint J 2015; 97-B:668–74

Introduction. Traditional treatment of idiopathic flatfoot in the adult population include calcaneal neck lengthening or fusions. These surgical methods result in abnormal function with significant complication rates. Our prospective study aimed to quantify the functional and radiological outcome of a new technique for spring ligament reconstruction using a hamstring graft, calcaneal osteotomy and medial head of gastrocnemius recession if appropriate. Methods. 22 feet were identified from the senior authors flatfoot reconstructions over a 3 year period (Jan 2013 to Dec 2015). 9 feet underwent a spring ligament reconstruction. The control group were 13 feet treated with standard tibialis posterior reconstruction surgery. Follow up ranged from 8 to 49 months. Functional assessment comprised VAS heath and pain scales, EQ-5D and MOXFQ scores. Radiographic analysis was performed for standardised parameters. Results. Each group contained two bilateral procedures. The spring ligament patients had a mean age of 43, BMI of 29 and a male to female ratio of 4;1 There were no statistical differences between groups starting point functional scores or pre-operative radiological deformity. Post-operatively there was a statistically significant improvement of all domains and overall MOXFQ, EQ5d and VAS in the spring ligament patients. There was a statistically significant improvement in all radiological parameters with all patients being returned to normal. Functional scores were not significantly better than the control group [MOXFQ components, Control vs spring ligament group, Pain: 42 vs 45 (p=0.71), Walking: 50 vs 56 (p=0.43), Social: 35 vs 39 (p=0.72), EQ-5D: 0.64 vs 0.70 (p=0.72)]. Spring ligament reconstruction produced statistically better deformity correction for 4 of 5 measured radiological parameters (p< 0.05). Conclusion. Our new method of spring ligament reconstruction restores normal anatomy. In comparison to traditional procedures our method provides equivalent functional results and improved deformity correction

Most of the controversy surrounding management of the adult acquired flatfoot deformity revolves around the correction of Stage 2 deformity. Stage 1 deformity, uncommonly corrected surgically, involves tenosynovitis with preservation of tendon length and absence of structural deformity. Attempts at tenosynovectomy in light of structural deformity leads to operative failure, found in 10% of Teasdall and Johnson's 1992 patient population. Thus, with tenosynovectomy rarely becoming an operative situation, Stage 2 deformity becomes the mainstay of operative treatment of the adult flatfoot. Stage 2 deformity patients present with swelling medially, the inability to do a single heel raise, with a passively correctable subtalar joint. The tendon is functionally torn. In recent years, authors have subdivided Stage 2 deformity even further into A and B subcategories, where A involves less than 50% uncovering of the talonavicular joint, and B patients more than 50%. Recently, Anderson has added a C subtype, which may be applied to either A and B patients, in patients who have forefoot varus. Thus, Stage 2 patients suffer from pain that begins medially and progresses to the subfibular region over time. Most important, recognition of the continued sub classification in Stage 2 disease echoes the fact that this disorder is on a continuum, challenging the surgeon to recognize subtleties that, if unrecognized, lead to a poor patient outcome. The mainstay of treatment in Stage 2 disease is the medial slide calcaneal osteotomy, which realigns the hindfoot axis reducing valgus, improves the medial arch, protects the FDL tendon transfer, and allows the Achilles tendon to become a strong inverter. Over shift of the calcaneus can compromise the outcome, as will a lack of recognition of the congenital subtleties such that a valgus hindfoot can have a varus orientation to the calcaneus, both leading to lateral overload. A pure medial slide of a calcaneus that has a varus orientation does not correct deformity, rather, it creates it. Thus, an axial calcaneal view must be studied carefully, for a varus orientation may be corrected via a closing wedge osteotomy commensurate with the medial shift of the tuberosity. As noted above, the flexor digitorum longus tendon transfer is the staple procedure to replace the damaged posterior tibial tendon. This transfer balances the eversion power of the peroneal tendons, works in phase with the former posterior tibial tendon in the stance phase of gait, and replaces a painful diseased posterior tibial tendon. However, over tensioning the transfer results in a tenodesis rather than a functional tendon transfer, the relative weakness of the FDL tendon (30% as strong as the PTT) creates difficulty with heel raise, and inappropriate transfer to distal tarsal bones may compromise the result by limiting torque from the transferred tendon. Preservation of the posterior tibial tendon in combination with the transferred FDL tendon remains a consideration without answer, though Rosenfeld (2005) suggests a substantial improvement in strength through PTT preservation. Failure of the above protocol for treating Stage 2 disease most often revolves around the insufficient corrective power of the tandem procedures in longstanding ruptures. According to Guyton (2001), only 50% of patients report a perception in deformity improvement following FDL/calcaneal osteotomy procedures, and only 4% report a significant improvement in pre-existing deformity. Sangeorzan (2001) found such patients could not achieve a painless plantigrade foot due to acquired ligament laxity (primarily the Spring Ligament). Sangeorzan applied Evans' pediatric procedure to adults without confirming the pathomechanics of correction. Some speculate the windlass effect on the plantar fascia creates correction (refuted by Horton, 1998, finding the plantar fascia is loosened by a lateral column lengthening), others believe tightening the peroneus longus through lateral column lengthening increases first ray plantarflexion, restoring the medial arch. Controversy also remains in answering Cooper's (1997) claim that lengthening through the calcaneus creates static increase in pressure about the calcaneocuboid joint (1.4mPa total) that may lead to an arthritic joint long term. Painful lateral overload following lateral column lengthening remains difficult problem to both prevent and correct. This last point leads to some focusing their efforts on restoration of the medial column. This group focuses on the “C” type deformity noted by Anderson, those with forefoot varus. It is known that the medial column is supported by the navicular, the cuneiforms, and the first, second, and third metatarsals. While a Cotton (opening wedge medial cuneiform) osteotomy, a first tarsometatarsal joint arthrodesis, or a metatarsal osteotomy has value, the surgeon must note that this only corrects the first ray. Complete correction of the medial column is best achieved through naviculocuneiform joint arthrodesis. Standing radiographs commonly reveal collapse at that level; however, surgeons are reticent to perform such fusions in light of the higher nonunion rate

Acquired flatfoot deformity after injury is usually due to partial or complete tearing of the tendon of tibialis posterior, with secondary failure of the other structures which maintain the medial longitudinal arch. We describe a patient in whom the rupture of the plantar calcaneonavicular (spring) ligament resulted in a clinical picture similar to that of rupture of the tendon of tibialis posterior. Operative repair of the ligament and transfer of the tendon of flexor digitorum gave an excellent result at four years with the patient returning to full sporting activities

Introduction:. The purpose of this study was to elucidate the specific radiographic effects that the Cotton osteotomy confers when used in combination with other reconstructive procedures in the management of the flexible flat foot deformity. Methods:. Between 2002–2013, 198 Cotton osteotomies were retrospectively identified following IRB approval. 131 were excluded on the basis of ipsilateral mid/hindfoot arthrodesis, inadequate radiographs or being less than 18yrs old at time of surgery. Parameters including the articular surface angles of the hindfoot/forefoot, Meary's angle and a newly defined Medial Arch Sag Angle (MASA) were recorded. A matched group of patients who did not undergo a Cotton osteotomy but who underwent similar hindfoot reconstructive procedures served as historic controls. Results:. 67 Cotton osteotomies in 59 patients with a mean age of 45 years (range, 18–80) were evaluated. Concomitant procedures included combinations of tibialis posterior tendon (PTT) reconstruction, Evans lateral column lengthening, medial displacement calcaneal osteotomy (MDCO). In all patients who underwent a Cotton osteotomy, there were statistically significant improvements in the articular surface angles along the medial side of the foot (p < 0.05). Improvement in arch height was also found to be statistically significant (p < 0.05). In comparison to matched controls, the Cotton osteotomy did not improve Meary's angle but provided an additional 11.21° of MASA correction (p < 0.05) when used in in conjunction with the Evans procedure and PTT reconstruction. A similar trend was seen with MDCO and PTT reconstruction. Discussion:. This study confirms the Cotton osteotomy is a powerful surgical adjunct in flatfoot reconstruction and quantifies the additional 11.21° of MASA correction it provides when the Cotton osteotomy is added to a calcaneal osteotomy and PTT reconstruction. This has relevance as an alternative for selection of a medial column stabilization procedure, which is joint sparing

Introduction. Medial calcaneal displacement osteotomy with an FDL tendon transfer is a common method of correcting pes planus deformity secondary to grade II tibialis posterior dysfunction. There is currently no evidence that calcaneal displacement alters the centre of pressure in the foot from a medial to a more central position as the normal shape is reconstituted. Materials and Methods. We prospectively evaluated 12 patients undergoing flatfoot reconstruction. Each patient had a preoperative AOFAS hindfoot score, pedobariographs and antero-posterior and lateral radiographs. This was repeated 6 months following surgery. Results. An angle (α) between the central axis of the foot (calcaneum to 2nd metatarsal head) and the centre of pressure (COP) was calculated for each patient both pre and post operatively and analysed using the Shapiro Wilk and the Students t test. Pressures directly under the 1st and 5th metatarsal heads and the calcaneum were also recorded and the pre and post operative differences analysed. The mean change in α angle is 6.1° (p < 0.01). The mean increase in pressure on the 1st metatarsal head is 460kPa (p = 0.08). The pressure changes on the 5th metatarsal head and the calcaneum are not statistically significant. The mean AOFAS score increases from 39.2 preoperatively to 82.8 postoperatively (p = 0.0019). The Meary angle improves from a mean of 12.7° to 5.7° (p = 0.027) and the calcaneal pitch improves from15.1° to 18.2° (p = 0.12). Conclusion. The medial displacement calcaneal osteotomy is able to significantly lateralise the centre of pressure in the foot and also increases the pressure under the 1st metatarsal head to more closely represent the parameters of the normal foot. The shape of the foot as judged radiographically and the clinical outcomes (AOFAS) are also improved

Introduction. Historically, surgeons have focused on isolated simple coalition resection in symptomatic tarsal coalition with concomitant rigid flat foot. However, a review of literature suggests that coalitions with severe preoperative planovalgus malposition treated with resection alone are associated with continued disability and deformity. We believe that concomittant severe flatfoot should be considered as much as a pathological component and pain generator as the coalition itself. Our primary hypothesis is that simple resection of middle facet tarsal coalitions and simultaneous flat foot reconstruction can improve clinical outcomes. Methods. Thirteen consecutively treated patients (eighteen feet) were retrospectively reviewed from the senior author's practice. Clinical examination, American Orthopaedic foot and Ankle Society (AOFAS) hindfoot scores, and radiographic assessments were evaluated after resection of middle facet tarsal coalitions with simultaneous flat foot reconstruction. Results. All patients with resection and simultaneous flat foot reconstruction (calcaneal lengthening, medial cuneiform osteotomy) were satisfied and would have the same procedure again. Most patients were able to return to a higher level of sporting activity compared with preoperative ability. None of the patients had a fair or poor outcome as adjudged by their AOFAS scores. Conclusion. Our study shows that concomittant flatfoot reconstruction in patients with symptomatic middle facet tarsal coalition increased hindfoot motion, corrected malalignment and significantly improved pain. We believe that coalition resection and concomitant flatfoot reconstruction is better option than surgical resection alone or hindfoot fusion in this cohort of patients. Triple arthrodesis should be reserved as a salvage procedure

Müller Weiss disease (MWD) is characterized by lateral navicular necrosis which is associated with a varus alignment of the subtalar joint, varying degrees of arthritis of the talonavicular-cuneiform joints and a paradoxical flatfoot deformity in advanced cases. Although arthrodesis of the hindfoot is commonly used, we present the results of a previously unreported method of treatment using a calcaneus osteotomy incorporating a wedge and lateral translation. Fourteen patients with MWD who were treated with a calcaneus osteotomy were retrospectively reviewed. There were seven females and seven males with an average age of 56 years (range 33–79), and included one grade 5, five grade 4, four grade 3 and four grade 2 patients. Patients had been symptomatic for an average of eleven years (range 1–14), and all underwent initial conservative treatment with an orthotic support that posted the heel into valgus. The primary indication for surgery was a limited but positive response to the use of the orthotic support, and a desire to avoid an arthrodesis of the hindfoot. Results. Patients were followed for an average of three years following the procedure (range 1 – 7 years). Patients rated their pain on a visual analogue pain scale as an average of 8 (range 6–9) prior to surgery and an average of 2 postoperatively (range 0–4). The AOFAS scores improved from a mean of 29 (range 25 – 35) preoperatively to a mean of 79 (range 75–88) postoperatively. Hindfoot range of motion remained and the extent of arthritis of the navicular complex was unchanged. No patient has since required an arthrodesis. Since the majority of MWD patients respond to an orthotic support which changes the load of the hindfoot and forefoot, we believed that patients would respond positively to a calcaneal osteotomy as an alternative treatment

Painful peroneal spastic flatfeet without coalition or other known etiologies in adolescence, remains a difficult condition to treat. We present eight such cases with radiological and surgical evidence of bony abnormalities in the lateral subtalar region just anterior to the posterior facet. All patients had presented as tertiary referrals with recalcitrant pain and had undergone a trial of orthotics and physiotherapy. Diagnostic workup included a clinical and radiographic evaluation. Clinical examination consisted of gait examination, foot alignment, range of motion, torsional profile of the lower limbs and marking of symptomatic foci. All patients had standing weightbearing anteroposterior and lateral projections of the foot and ankle, CT and/or MRI scans of the foot. Coalitions and other known intra-articular pathologies like subtalar arthritis were ruled out. All patients had bilateral flatfeet but unilateral peroneal spasm. All patients had an accessory anterolateral talar facet (ATF) which was arising as an anterior and distal extension of the lateral process of the talus. This caused lateral impingement between the facet and the calcaneum, confirmed by bone edema around the sinus tarsi and marked at the apex of the angle of Gissane on MRI scans. All patients had stiff subtalar joints with very limited movement under anaesthesia, indicating peroneal muscle contracture. Patients were treated with a combination of facet excision, fractional peroneal and gastrosoleus lengthening and calcaneal lengthening to correct the flatfoot and prevent lateral impingement

Introduction. Flexor digitorum longus (FDL) transfer and medial displacement calcaneal osteotomy (CO) is a well-recognised surgical treatment for stage II posterior tibial tendon dysfunction (PTTD). Whilst excellent results are quoted for short and medium term follow-up, the long-term outcome of this procedure is unknown. Materials and Methods. We reviewed the clinical outcome of patients with a symptomatic flexible flatfoot deformity undergoing this procedure at a mean follow up of 15.3 +/−0.7 years (range 14.4–16.5). We identified 48 patients who underwent surgery by the senior author between 1994 and 1996. We were able to contact 30 patients of whom 20 were available for clinical review. 10 patients participated via telephone interview, and also completed postal questionnaires. Results. All scores improved significantly from preoperative to latest follow-up. The mean AOFAS score improved from 48.4 presurgery to 90.0+/−13.6 (range 54–100) postsurgery. The pain component improved from a mean of 12.3 to 35.0+/−8.1 (range 20–40). Function score improved from 35.8 to 45.5+/−6.1 (range 30–50). Visual analogue score improved from 7.3 to 1.3+/−2.2 (range 0–6). Seven patients had only fair objective alignment, however six of those were totally satisfied and one satisfied with minor reservations, and all said they would have the surgery again. The mean SF36 physical component score was 39.8+/−8.4 and this showed significant correlation with the AOFAS score (r = 0.61, p = 0.009). Five patients developed further pain unresponsive to analgesia and orthotics and underwent further surgery in the form of calcaneocubuoid fusion, talonavicular fusion or triple fusion at a mean of 5.5+/−4.7 years (range 0.7–11.8) following initial surgery. 25(83%) patients were pain free and functioning well at an average of 15.3 years following surgery. Conclusion. We believe that FDL transfer and CO provides long-term pain relief and satisfactory function in the treatment of Stage II PTTD

Introduction. Medial column insufficiency in patients with painful acquired flatfoot can be difficult to appreciate. The reverse Coleman block test (as described and published by Mr E Wood in 2009) is used in this study to predict medial column instability. Methods. Patients who underwent a procedure for medial column insufficiency with use of the reverse Coleman block test pre-operatively were investigated. Weight bearing radiographs were used to determine the joints in the medial column contributing to the deformity and also to estimate the angle which the first ray must be depressed to re-establish hindfoot neutrality. The reverse Coleman block test corrects a mobile valgus heel to a neutral position by placing a block, of appropriate height, under the first metatarsal head. With the heel in neutral and the relative forefoot supination compensated the foot returns to a neutral anatomic position. Gender, age, complications and radiological outcomes were investigated. Results. Over the last three years 25 medial column procedures were performed for painful insufficiency on 17 females and five males by the senior author. Three patients underwent staged bilateral procedures. The average age was 62 years old. Three feet had been on operated on the medial column previously. The pre-operative weight bearing lateral radiographs showed instability in the medial column greater than 5° in 12 cases. With the reverse Coleman block test instability was seen in 25 cases and the deformity increased from an average of 7° (range 0° to 25°) to 14° (range 5° to 30°). Post-operative weight bearing radiographs, with fusion of the unstable joint, the average medial column alignment was 1° (range -10° to 10°). Three patients developed superficial infections requiring oral antibiotics for treatment. One patient had a non-requiring revision surgery. Discussion. The reverse Coleman block test revealed instability in 13 out of 27 cases not seen with simple weight bearing lateral radiographs. The test also on average doubled the size of any deformity seen. This aided pre-operative planning to predict the scale of deformity correction required. Conclusion. The reverse Coleman block test is a useful test to determine medial column insufficiency and assist with pre-operative planning

The last decade has seen a considerable increase in the use of in total ankle arthroplasty (TAA) to treat patients with end-stage arthritis of the ankle. However, the longevity of the implants is still far from that of total knee and hip arthroplasties.

The aim of this review is to outline a diagnostic and treatment algorithm for the painful TAA to be used when considering revision surgery.

Cite this article: Bone Joint J 2017;99-B:5–11.

We describe a retrospective review of the clinical and radiological parameters of 32 feet in 30 patients (10 men and 20 women) who underwent correction for malalignment of the hindfoot with a modified double arthrodesis through a medial approach. The mean follow-up was 21 months (13 to 37). Fusion was achieved in all feet at a mean of 13 weeks (6 to 30). Apart from the calcaneal pitch angle, all angular measurements improved significantly after surgery. Primary wound healing occurred without complications.

The isolated medial approach to the subtalar and talonavicular joints allows good visualisation which facilitated the reduction and positioning of the joints. It was also associated with fewer problems with wound healing than the standard lateral approach.

The foot and ankle outcome score (FAOS) has been evaluated for many conditions of the foot and ankle. We evaluated its construct validity in 136 patients with osteoarthritis of the ankle, its content validity in 37 patients and its responsiveness in 39. Data were collected prospectively from the registry of patients at our institution.

All FAOS subscales were rated relevant by patients. The Pain, Activities of Daily Living, and Quality of Life subscales showed good correlation with the Physical Component score of the Short-Form-12v2. All subscales except Symptoms were responsive to change after surgery.

We concluded that the FAOS is a weak instrument for evaluating osteoarthritis of the ankle. However, some of the FAOS subscales have relative strengths that allow for its limited use while we continue to seek other satisfactory outcome instruments.

Cite this article: Bone Joint J 2015; 97-B:662–7.

We developed the Oxford ankle foot questionnaire to assess the disability associated with foot and ankle problems in children aged from five to 16 years. A survey of 158 children and their parents was carried out to determine the content, scaling, reliability and validity of the instrument. Scores from the questionnaire can be calculated to measure the effect of foot or ankle problems on three domains of children’s lives: physical, school and play, and emotional. Scores for each domain were shown to be internally consistent, stable, and to vary little whether reported by child or parent. Satisfactory face, content and construct validity were demonstrated. The questionnaire is appropriate for children with a range of conditions and can provide clinically useful information to supplement other assessment methods. We are currently carrying out further work to assess the responsiveness of questionnaire scores to change over time and with treatment.