title: Histologic analysis of postmeniscectomy osteonecrosis.
abstract: Bone marrow signal changes on magnetic resonance imaging (MRI) after meniscectomy have been reported as evidence of postmeniscectomy osteonecrosis, but this pathology is unclear. We conducted a study to follow-up cases with bone marrow signal changes on MRI after meniscectomy and investigate the pathology of underlying lesions. Of 136 patients with no presurgical evidence of osteonecrosis, 29 had juxta-articular bone marrow signal changes on MRI after arthroscopic meniscectomy and subsequently underwent conservative therapy. In 6 of these 29 patients, clinical symptoms and radiographic changes began deteriorating. Based on the Koshino classification, 4 of the 6 patients had Stage-2 knee osteonecrosis and 2 had Stage-3. Arthroscopic and pathologic examinations were performed. Arthroscopic findings were fibrillation (all 6 cases), fissuring (4), ulceration (2), and eburnation (2). Histologic analysis confirmed subchondral bone fractures in all 6 cases, but osteonecrotic lesions were detected only in 2 cases with obvious radiologic deterioration. Postmeniscectomy osteonecrosis might result from subchondral bone fractures. Fracture healing is worse in patients with comorbidities than in those without it; comorbidities might be a risk factor for osteonecrosis.
authors.affiliation: Department of Orthopaedic Surgery, Asakura Sports Rehabilitation Clinic, Maebashi, Gunma, Japan. jaguar156z@yahoo.co.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Higuchi
authors.forename: Yasukazu
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kobayashi
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Hatayama
authors.forename: Masashi
authors.initials: M
authors.lastname: Kimura
mesh_terms: D000368:Aged; D001182:Arthroscopy / Q000009:adverse effects*; D001853:Bone Marrow / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000473:pathology* / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008592:Menisci, Tibial / Q000473:pathology* / Q000601:surgery; D008875:Middle Aged; D010020:Osteonecrosis / Q000209:etiology / Q000473:pathology* / Q000601:surgery