Midfoot arthritis causes chronic foot pain and significant impairment of daily activities. Although post traumatic arthritis and primary osteoarthritis are the most common pathologies encountered, surgeons need to rule out inflammatory causes and neuropathic aetiology before starting treatment. Steroid Injections are invaluable in conservative management and have diagnostic value in guiding surgical treatment. For the definitive surgical option of fusion there are a variety of fixation devices available. A successful union is linked to a satisfactory outcome which most authors report to be in the range of 90% following the key principles of careful patient selection, pre-operative planning, adequate joint preparation and a stable fixation.

INTRODUCTION Arthroscopy of the ankle has gained acceptance as a procedure for diagnosing and treating chronic and post-traumatic ankle problems. The senior author's perception is that magnetic resonance imaging (MRI) under-diagnoses anterior soft tissue impingement lesions in children. The purpose of this study was retrospectively to analyse the outcome of ankle arthroscopy in the paediatric age group. PATIENTS AND METHODS Between March 2005 and September 2007, 23 children underwent ankle arthroscopy for post-traumatic pathology. The indications for arthroscopy were failure of non-operative treatment for at least 12 weeks or a grade 3 or 4 osteochondral defect (OCD) on imaging. RESULTS At arthroscopy, OCDs were visualised in 12 cases and impingement lesions were seen in 17 ankles. MRI was performed in 8 of these 12 cases and only 1 suggested the possibility of an impingement lesion. Of the 17 cases of impingement seen on arthroscopy, 12 reported mechanical symptoms preoperatively and 4 were unstable on examination under anaesthetic. Eighteen of the twenty-three patients had complete relief of symptoms at 3 months. Eighteen children who were evaluated at one-year follow up had a mean American Orthopaedic Foot and Ankle Society score of 87. 5 (range: 49-100). CONCLUSIONS Ankle arthroscopy has a successful outcome in paediatric patients and the results are comparable with those reported in adult series. MRI was found to be insensitive for the diagnosis of soft tissue impingement of the ankle.