Nonunions of the proximal humerus: their prevalence and functional outcome.

BACKGROUND: : We present an analysis of the prevalence of proximal humeral nonunions and an assessment of their functional outcome. METHODS: : The results of a study of 11 proximal humeral nonunions taken from a previous prospective study of 1,027 consecutive proximal humeral fractures were analyzed to determine the demography of the patient population, the Constant and Neer scores at 6 weeks, 13 weeks, 26 weeks, and 1 year and the functional outcome of the patients. All patients had been followed for 1 year and standard anteroposterior and modified axial X-rays taken at each assessment. The possible factors associated with proximal nonunion were studied. RESULTS: : The prevalence of proximal humeral nonunion is 1.1%, although it rises to about 8% if metaphyseal comminution is present and 10% if there is between 33% and 100% translation of the surgical neck. The effect of nonunion on function is considerable, even as early as 6 weeks after fracture. Our results show a deterioration of overall glenohumeral function after 6 months compared with patients whose fractures unite. Return to routine activities of daily living is markedly slower in the presence of a nonunion. The nonunions occurred in older patients but the age difference was not statistically significant. CONCLUSIONS: : Our results show that nonunion after nonoperative treatment of proximal humeral fractures is much less than has previously been reported and they suggest that age, metaphyseal comminution and fracture displacement are all factors in the development of nonunion. They also indicate that if operative treatment is required for proximal humeral nonunion it should not be delayed beyond 6 months after fracture and ideally should be performed as soon as the presence of a nonunion has become established this frequently being about 3 months after fracture.