Melorheostosis of the Fossa Intercondylaris Femoris – A Case Report and Review of the Literature

INTRODUCTION: Melorheostosis is a rare benign bone condition characterized by excessive segmental sclerosis of cortical bone being reminiscent of dripping candle wax. It typically affects the long bones and can cause impingement and nerve compression syndromes that may require surgical treatment. CASE REPORT: We report the case of a 49-year-old male patient with a 12-month history of the left-sided knee pain and a concomitant limitation of his left knee flexion to 90 degree. Radiographic and magnetic resonance imaging revealed the typical radiographic appearance of melorheostosis with an extraosseous lesion in the fossa intercondylaris femoris being causative for the limited knee range of motion. Following the resection of the extraosseous part of the lesion through a direct open approach, the patient is pain free with a maximum of 110 degree knee flexion at 12-month follow-up. CONCLUSION: Melorheostosis can present with manifold clinical manifestations that potentially require surgical treatment. Even in patients with a challenging localization of extraosseous lesions, a good to excellent functional outcome is possible.