Predictors of failure of nonoperative treatment for type-2 supracondylar humerus fractures

Closed reduction and casting for type-2 supracondylar fractures is a viable treatment option, but studies have shown that some patients will fail to maintain the initial reduction in a cast. This study sought to identify predictors of failed treatment of closed reduction and casting for these fractures.

We performed a retrospective case-control study of type-2 supracondylar fractures treated by closed reduction and casting. Using radiographic failure of reduction as our primary outcome measure, we examined injury, postreduction, and follow-up films evaluating the anterior humeral line, cast flexion angle, and degree of cast padding in an attempt to identify predictors of failure.

We reviewed 645 fractures. Of 126 type-2 fractures, 61 fractures were included in the study. There were 49 (80%) nonoperative treatment successes and 12 failures (20%) with an average follow-up of 41 days (range, 20 to 161 d). We found that (1) the degree of fracture extension using an index based on the anterior humeral line on the injury film was significantly related to failure of cast treatment (P=<0.01), and (2) the width of the soft tissue shadow of the upper arm on the postreduction film was of borderline significance (P=0.02). Cast flexion angle and cast padding were not predictive of radiographic loss of reduction (P=0.94 and 0.70).

Despite adequate reduction and casting of type-2 supracondylar fractures, some fractures will lose reduction and require delayed pinning. The degree of extension of the distal fragment at the time of injury may help to predict the likelihood of failure of nonoperative treatment.