Homologous osteochondral graft transplantation for spontaneous bilateral osteonecrosis of the femoral condyle in a young patient: case report and narrative review

Spontaneous osteonecrosis of the knee (SONK) is a rare degenerative disease, the causes of which remain largely unknown. SONK develops gradually, leading to progressive pain with functional impairment, and is often misdiagnosed due to the complexity of the clinical examination, which is hampered by pain and swelling. Early diagnosis and treatment are essential to prevent joint damage and ensure good functional outcomes. We review the current literature on SONK and present a case of bilateral SONK in a 31-year-old woman who was treated with a homologous osteochondral implant. The patient of this case report had high functional demands and no comorbidities. A two-stage procedure was performed including diagnostic arthroscopy, removal of subchondral sclerosis, and allograft insertion using the compression-fit technique. At 36-month follow-up, the patient reported significant functional improvement and a reduction in pain, demonstrating the effectiveness of this therapeutic approach.