Management Dilemma of a Neuropathic Knee in a Known Case of Larsen Syndrome: A Case Report.

Introduction: Larsen syndrome (LS) is a rare genetic disorder affecting mainly the connective tissues. It is characterized by characteristic facial anomalies, cervical kyphosis, cardiorespiratory disorders, and multiple joint dislocations. We present a case of a 15-year-old male with unstable neuropathic knee joint instability in a known case of LS. The paucity of literature on the management of this rare condition puts an orthopedician in dilemma regarding the optimal treatment. Case Report: A 15-year-old male, known case of LS, presented to our outpatient department with pain and instability in the right knee for 2 years. Clinically, the patient was having syndromic facies. The diagnosis of LS was confirmed on gene mapping. The right knee was swollen with medial joint line tenderness and restricted flexion. The patient had coronal plane valgus instability. The hypertrophied synovium eroded the articular surface. The radiograph of knee was suggestive of neuropathic arthropathy in fragmentation stage. Conclusion: Orthopedician should be aware of such rare entity with its bony and soft-tissue manifestations. Neuropathic knee is not an absolute contraindication to total knee replacement, especially with advanced prosthesis. Primary arthrodesis to be considered in young adults with instability.