Shoulder Osteonecrosis: Pathogenesis, Causes, Clinical Evaluation, Imaging, and Classification

Abstract

The humeral head is the second most common site for nontraumatic osteonecrosis after the femoral head, yet it has attracted relatively little attention. Osteonecrosis is associated with many conditions, such as traumatism, corticosteroid use, sickle cell disease, alcoholism, dysbarism (or caisson disease), and Gaucher's disease. The diagnosis is clinical and radiographic with MRI, with radiographs being the basis for staging. Many theories have been proposed to decipher the mechanism behind the development of osteonecrosis, but none have been proven. Because osteonecrosis may affect patients with a variety of risk factors, it is important that caregivers have a heightened index of suspicion. Early detection may affect prognosis because prognosis is dependent on the stage and location of the disease. In particular, the disease should be suspected in patients with a history of fractures, steroid usage, or sickle cell disease, and in divers. This report reviews osteonecrosis of the humeral head, with an emphasis on causes, clinical evaluation, imaging, and classification.

Keywords: Corticosteroids shoulder osteonecrosis; Dysbarism shoulder osteonecrosis; Humeral head osteonecrosis; Posttraumatic humeral head osteonecrosis; Sickle cell disease shoulder osteonecrosis.

Fig. 1

Posttraumatic radiograph of humeral head and evolution to osteonecrosis.

Fig. 2

Vascularization of the humeral head.

Fig. 3

(A) No hinge with high risk of osteonecrosis; (B) hinge (arrow) and low risk of osteonecrosis.

Fig. 4

Osteonecrosis related to corticosteroids: accumulation of fat; subchondral fracture indicated by the arrow.

Fig. 5

Repartition of sickle cell disease in the world.

Fig. 6

Mechanism of osteonecrosis in sickle cell disease; the polymerization (A and B) of hemoglobin S (in a deoxygenated state) producing cells that are crescent‐shaped or sickle‐shaped (C and D) with decreased deformability; the decreased deformability results in greater risk of clotting (E) in small vessels.

Fig. 7

Shoulder osteonecrosis in a diver with a fatal decompression accident of: post mortem images (radiograph and anatomy) of osteonecrosis (arrows) in the proximal humeral head.

Fig. 8

MRI appearance of early shoulder osteonecrosis: band‐like hypo‐intense (arrow) zones on T1‐weighted images demarcating the osteonecrosis.

Fig. 9

Area of high‐intensity signal on T2‐weighted images of osteonecrosis (arrow) on MRI.

Fig. 10

Different location of osteonecrosis on the humeral head.

Fig. 11

Classification of stages for shoulder osteonecrosis.

Fig. 12

There is good correlation between different exams for stages.