Humerus varus: a complication of neonatal, infantile, and childhood injury and infection.

Sixteen cases of humerus varus consequent to proximal humeral fracture and osteomyelitis are described. A similar, but variably severe pattern of progressive deformity occurred in all cases. The medial region of the proximal humeral physis usually either developed slowly or failed to develop, whereas the lateral region developed more normally. This caused progressive angular rotation of the proximal humeral epiphysis and physis, so that the lateral region of the growth plate, in its most severe expression, was almost aligned with the longitudinal axis of the shaft. In the majority of the cases, there was a medial-metaphyseal lucency and adjacent medial-osseous bridge. In some cases, a flattened epiphysis and central bridge were present, with less varus deformation with progressive growth. Shortening of the humerus occurred in all cases. Functional impairment, usually a mild to moderate limitation of glenohumeral abduction, was infrequent, even when the dominant arm was involved. Axial lengthening may yet be undertaken. Surgical realignment with a corrective (valgus) osteotomy of the proximal humerus does not, however, appear functionally necessary for all patients.