Papers of the Week

Post-arthroscopic osteonecrosis is a rare complication of arthroscopic surgery. The present study reported on a case of knee osteonecrosis after arthroscopic surgery. The patient, an 81-year-old male, presented with left knee pain and limited range of motion without any history of trauma. MRI revealed medial meniscus tear. Medial partial meniscectomy was performed using arthroscopy. The pain was found to be relieved due to the operation. However, there was an aggravation of pain after two months post-operatively. X-ray revealed that the subchondral bone in the medial femoral condyle (MFC) had collapsed. MRI revealed a large area of bone marrow edema in the MFC with cartilage delamination and subchondral flattening. Considering the age of the patient and the large area of bone necrosis, total knee arthroplasty was performed. At the 1-year follow-up, the Knee Society Knee Score improved from 44 points pre-operatively to 90 points and the Knee Society Functional Score was elevated from 35 to 90 points. Patient-reported outcome measures were assessed in the form of the Oxford Knee Score, which was 16. Furthermore, previous case reports of post-arthroscopic osteonecrosis were reviewed and the clinical and radiographic features, as well as the treatment, were summarized. If the patient complains of persistent and worsening pain after arthroscopy, particularly in elderly osteoporotic patients with meniscal tears or chondral lesions, the possibility of post-arthroscopic knee osteonecrosis should be considered. Diagnosis and treatment at the early stages are likely to be beneficial for the outcome.