Sequential Development and Staged Management of Distal Femoral Osteochondroma with Progressive Bilateral Genu Valgum: A Case Report.

Introduction: Osteochondromas are among the most frequently encountered benign bone tumors, yet their association with progressive angular deformity in the coronal plane is uncommon. This case is, to our knowledge, not well characterized in the existing literature and highlights the possibility of contralateral deformity progression following unilateral surgical correction of a solitary osteochondroma. Case Report: We describe the clinical course of a young adult male who presented with a left distal femoral osteochondroma in 2022, managed surgically with concurrent correction of an associated genu valgum deformity. Over the ensuing months, the patient developed progressively worsening valgus deformity on the contralateral right knee, ultimately requiring a separate corrective osteotomy in 2023. This sequential, bilateral progression in a patient with a solitary lesion is exceptionally rare. Conclusion: Both interventions yielded satisfactory outcomes, with restoration of limb alignment and meaningful functional recovery. This report draws attention to the possibility of contralateral deformity progression in such patients and underscores the value of sustained bilateral post-operative surveillance. The case contributes to the limited literature on deformity progression associated with solitary osteochondroma and has direct clinical impact for orthopedic surgeons managing similar presentations.