Flexion-Type Supracondylar Humeral Fractures: Ulnar Nerve Injury Increases Risk of Open Reduction

The vast majority of displaced pediatric supracondylar humeral fractures can be treated successfully with closed reduction and percutaneous pinning. The need for open reduction is difficult to determine a priori and is typically due to the failure of closed reduction attempts or persistent limb ischemia. The aims of this study were to determine the prevalence of flexion-type supracondylar humeral fractures, the rate of open reduction for flexion-type fractures, and the predictive impact of ulnar nerve injury on the need for open reduction for flexion-type supracondylar humeral fractures.

We developed a database of consecutive pediatric supracondylar humeral fractures treated operatively at a tertiary care pediatric trauma center from 2000 to 2015. Data recorded included age, mechanism of injury, fracture type (open or closed), fracture pattern (flexion-type or extension-type), concomitant skeletal injury, neurovascular injury, treatment, and surgeon. Radiographs of all flexion-type supracondylar humeral fractures were reviewed in order to confirm the classification of the injury pattern. The rate of open reduction for fractures with a flexion-type injury pattern and for such fractures with and without ulnar nerve injury at presentation was assessed.

Of 2,783 consecutive pediatric supracondylar humeral fractures treated by surgeons at our center, 95 (3.4%) were flexion-type fractures. Ulnar nerve injury was noted for 10 (10.5%) of the 95 flexion-type fractures. Open injuries were identified at presentation in 3 (3.2%) of the 95 cases. Among closed fractures, 21 (22.8%) of 92 flexion-type fractures required open reduction compared with 50 (1.9%) of 2,647 extension-type fractures (odds ratio [OR] = 15.4; 95% confidence interval [CI] = 8.8 to 27.0; p < 0.001). Among closed flexion-type fractures, open reduction was performed in 6 (60%) of 10 fractures with associated ulnar nerve injury and in 15 (18.3%) of 82 fractures without ulnar nerve injury (OR = 6.7; 95% CI = 1.7 to 26.7; p = 0.003).

Among closed supracondylar humeral fractures, the flexion-type injury pattern was associated with a 15.4-fold increase in the odds of open reduction. The presence of an ulnar nerve injury at presentation resulted in an additional 6.7-fold higher risk of open reduction among flexion-type supracondylar humeral fractures. Patients and families should be counseled regarding the high rate of open reduction for flexion-type supracondylar humeral fractures, particularly those with an associated ulnar nerve injury.

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.