SURGERY FOR NON-TRAUMATIC NECROSIS OF THE HUMERAL HEAD: ANALYSIS OF 771 CASES WITH 13 YEARS FOLLOW-UP (RANGE 5–23 YEARS)

Abstract

Purpose of the study: The humeral head is the second most frequent localization of non-traumatic osteonecrosis. For certain etiologies, for example sickle-cell anemia, the frequency is similar to that observed for the femoral head. There have nevertheless been very few publications on this pathology and its treatment. The purpose of this study was to assess outcome in a series of 771 cases of humeral head osteonecrosis in order to establish the natural history of the disease, criteria predictive of outcome, and therapeutic options.

Material and methods: The diagnosis of osteonecrosis of the humeral head was established for 771 humeri in 424 patients between 1981 to 2000. Minimum follow-up was five years (maximum 23 and mean 13 years). Outcome was assessed in terms of the clinical course, specifically the need for surgery due to pain or functional impotency. The radiological assessment was made on serial AP and lateral views taken every year or two years. The extent of the osteonecrosis was assessed on the basis of the magnetic resonance imaging (MRI) findings when available (after 1985). The ARlet and Ficat classification established for the femoral head was adapted to the shoulder: grade I: osteonecrosis of the humeral head visualized solely with MRI; grade II: radiologically detectable osteonecrosis; grade III: subchondral dissection without loss of spherical shape: grade IV: loss of spherical shape without visible osteoarthritis: grade V: osteoarthritis.

Results: Bilateral osteonecrosis was observed in 82% of the 424 patients. This gave 771 cases of humeral head necrosis. There was no gender predominance. Mean age at diagnosis was 32 years (range 18–57 years). The most frequent etiology was sickle-cell anemia (307 patients), followed by corticosteroid therapy (80 patients). Other etiologies were much less frequent: alcohol abuse, Gaucher’s disease, hyperlipidemia. Osteonecrosis of the humeral head was generally associated with another localization, particularly involving the hip and the knee joints. Multifocal osteonecrosis was also a common finding. Among the patients whose dignosis of osteonecrosis was established before symptom onset (scintigraphy or MRI performed in patients with multifocal osteonecrosis), the natural history was on average three years between MRI diagnosis and onset of pain. For 46% of the cases, pain appeared at grade I, before the development of radiographic signs. In 54% of the cases, grade II occurred before pain. It took six years before all of the cases with osteonecrosis diagnosed in a non-symptomatic phase produced pain. Factors affecting the rapidity of the radiological course were: etiology, size of the necrotic focus, presence and rapidity of osteonecrosis in other localizations (hip and knee). The humeral head lost its spherical shape on average four to five years after the diagnosis of osteoarthritic degradation of the joint, at about seven to eight years of evolution. Among the 256 patients followed for more than ten years, 51% required surgery. These 131 operations were for: drilling with bone marrow grafting (grade I or II) (n=62), cimentoplasty after loss of spherical shape but before glenohumeral osteoarthritis (n=15), resection of sequestered necrosis after loss of spherical shape (n=12), shoulder arthroplasty (n=42).

Discussion and conclusion: This study demonstrated that the natural history of osteonecrosis of the humeral head has a poor long-term outcome. Shoulder arthroplasty is rarely required during the first decade of the disease. Other therapeutic alternatives can help avoid or retard the need for shoulder arthroplasty in these very young patients.