Long-term results following intra-articular fractures of the medial malleolus in children and adolescents with special emphasis on MRI

Purpose: Presently, there is no publication combining clinical follow-up with magnetic resonance imaging (MRI) to determine possible post-traumatic alterations following paediatric intra-articular fractures of the medial malleolus. Therefore, the aims of this study were to retrospectively analyze a cohort of patients with Salter–Harris (SH) III and IV fractures of the medial malleolus and to evaluate their long-term outcome. MRI was used to assess possible changes of the articular surface that cannot be diagnosed on native radiographs.Patients and Methods: Fifty-four patients with SH III ( n = 38) or IV fractures ( n = 17) of the medial malleolus treated between 2001 and 2011 were invited for a follow-up examination. Clinical outcome was assessed with the Weber score and osteoarthritis with the Kellgren and Lawrence classification. MRI was rated by the Outerbridge classification. Correlations between the clinical and radiological outcomes were calculated.Results: Seventeen patients were recruited for long-term follow-up at a mean of 112 (range, 65–184) months. The Weber score was very good for 5 patients, good for 10 patients and poor for 2 patients; the Kellgren and Lawrence score revealed a favourable grade 0 in 15 patients and grade 1 in 2 patients. The MRI-based Outerbridge classification yielded grade 0 for 12 patients, grade 1 for 1 patient, grade 2 for 2 patients and grade 3 for 1 patient. The Outerbridge score significantly ( p < 0.05) correlated with the Weber score.Conclusion: This study shows excellent and good outcome of SH III and IV fractures of the medial malleolus. Worse clinical outcome correlated with post-traumatic changes of the articular cartilage seen on MRI.