Proximal Humeral Fractures: More Data on Nonunion Risk

Proximal humeral fractures tend to occur in a bimodal distribution, namely, in younger, primarily male patients and in older (>65 years of age), primarily female patients. In the latter population, such fractures are often related to low bone density, and we in the orthopaedic community now recognize the imperative to evaluate at-risk individuals through measures such as DXA scanning and laboratory assessments of bone health in order to institute appropriate monitoring and pharmacotherapy.

Regarding the treatment of these fractures, several large trials have demonstrated that, for select fracture patterns, nonsurgical care results in clinical and functional outcomes that are equal to or better than surgical care with open reduction and internal fixation or arthroplasty. The question for treating clinicians is: are there proximal humeral fracture patterns that have higher rates of complications (chiefly nonunion) following nonsurgical care?

In a retrospective study reported in JBJS, Goudie and Robinson evaluated the rate of nonunion among patients who were treated nonoperatively for a proximal humeral fracture at their regional trauma center in the UK. They also sought to develop and validate a prediction model to assess nonunion risk, measuring the effect of 19 patient demographic and radiographic variables on healing.

Overall, 231 (10.4%) of the 2,230 included patients experienced nonunion. Among those with valgus angulation of the humeral head (395 patients), the nonunion prevalence was <1%, and none of the other variables evaluated were associated with increased risk of nonunion in a multivariable analysis. However, among the 1,835 patients with neutral or varus angulation of the head, the prevalence of nonunion was 12.4%, and decreasing head-shaft angle, increasing head-shaft translation, and smoking were independently predictive of nonunion.

Important to note is the residual pain and diminished function that often accompanies nonunion. Still, the authors rightly point out that “surgery aimed solely at preventing nonunion exposes patients to the risk of other complications that are not encountered with nonoperative treatment.” But, based on these findings about fracture morphology, they conclude that “medically fit patients with translated and/or angulated fractures should be counseled about smoking cessation and considered for surgery to avoid the debilitating effects of subsequent nonunion.” Patients with these fracture characteristics deserve closer scrutiny in our efforts to provide the best treatment for proximal humeral fractures.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

Click here for a JBJS Clinical Summary on proximal humeral fractures.