Severe valgus deformity of the knee with permanent patellar dislocation associated with melorheostosis: a case report and review of the literature

Knee. 2014 Mar;21(2):589-93. doi: 10.1016/j.knee.2012.11.004. Epub 2013 Jan 8.

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.

Keywords: Ectopic ossification; Melorheostosis; Patellar dislocation; Soft tissue contracture; Valgus deformity of the knee.

Publication types

  • Case Reports
  • Review

MeSH terms

  • Child
  • Contracture / etiology
  • Contracture / surgery
  • Genu Valgum / diagnostic imaging
  • Genu Valgum / etiology*
  • Genu Valgum / pathology
  • Genu Valgum / surgery*
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Melorheostosis / complications*
  • Muscle, Skeletal / surgery
  • Patellar Dislocation / diagnostic imaging
  • Patellar Dislocation / etiology*
  • Patellar Dislocation / pathology
  • Patellar Dislocation / surgery*
  • Patellar Ligament / surgery
  • Radiography