title: Severe valgus deformity of the knee with permanent patellar dislocation associated with melorheostosis: a case report and review of the literature.
abstract: We present a case of an 8-year-old boy diagnosed with melorheostosis who was suffering from severe genu valgum, permanent dislocation of the patella, knee flexion contracture and leg length shortening. Soft tissue contracture of the limb and subsequent joint deformities were reported to represent clinical manifestations of pediatric melorheostosis. As the epiphyseal plate had not closed, patellar reduction was achieved by soft tissue surgical stabilization, including lateral retinacular release, medial retinaculum plication, and transfer of the lateral half of the patellar tendon. At 4 years postoperatively, as a result of improved limb alignment and knee flexion contracture, the leg length shortening has improved, and the patient does not limp and participates in sports activities. Surgical intervention should be performed as early as possible, because genu valgum and external rotation of the tibia may deteriorate with age, rendering the patellar dislocation irreversible in patients with melorheostosis before epiphyseal closure.
authors.affiliation: Department of Orthopaedic Surgery, Keio University, School of Medicine, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kitta
authors.affiliation: Department of Orthopaedic Surgery, Keio University, School of Medicine, Japan. Electronic address: y.niki@lib.bekkoame.ne.jp.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Niki
authors.affiliation: Department of Orthopaedic Surgery, Keio University, School of Medicine, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Udagawa
authors.affiliation: Department of Orthopaedic Surgery, Keio University, School of Medicine, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Enomoto
authors.affiliation: Department of Orthopaedic Surgery, Keio University, School of Medicine, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Toyama
authors.affiliation: Department of Orthopaedic Surgery, Keio University, School of Medicine, Japan.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Suda
mesh_terms: D002648:Child; D003286:Contracture / Q000209:etiology / Q000601:surgery; D056304:Genu Valgum / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology / Q000601:surgery*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008557:Melorheostosis / Q000150:complications*; D018482:Muscle, Skeletal / Q000601:surgery; D031222:Patellar Dislocation / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology / Q000601:surgery*; D017847:Patellar Ligament / Q000601:surgery; D011859:Radiography
keywords: Ectopic ossification; Melorheostosis; Patellar dislocation; Soft tissue contracture; Valgus deformity of the knee