Low incidence of ulnar nerve injury with crossed pin placement for pediatric supracondylar humerus fractures using a mini-open technique.

OBJECTIVES: Several recent studies have suggested that medial pinning in pediatric supracondylar humerus fractures leads to increased rates of ulnar nerve injury. The purpose of this study was to determine the risk of iatrogenic ulnar nerve injury in a consecutive series of supracondylar fractures treated using a standardized technique of crossed pin placement.

DESIGN: Single cohort retrospective.

SETTING: Metropolitan university tertiary care center.

PATIENTS AND PARTICIPANTS: Seventy-one consecutive children with Gartland type II or type III supracondylar humerus were treated surgically by 2 pediatric orthopaedic surgeons at 1 institution between 1995 and 2000 using a medial mini-open and cross-pinning technique. Sixty-five patients were available for follow-up (92%).

INTERVENTION: Patients were treated with a combination of medial and lateral pins using a mini-incision technique.

MAIN OUTCOME MEASUREMENTS: Outcomes analyzed included ulnar nerve injury and clinical and radiographic evidence of healing.

RESULTS: The study group consisted of 65 patients, of whom 29 (45%) presented with Gartland type III fractures, and the remaining 36 (55%) presented with a type II fracture. There were no ulnar nerve motor injuries. One patient was noted to have transient sensory changes in the ulnar nerve distribution postoperatively, which resolved by the 1-week follow-up visit. All patients were noted to have normal ulnar motor and sensory nerve function at final follow-up (average 4.5 months). No cases of nonunion, malunion, or infection were identified during the follow-up period.

CONCLUSIONS: The rate of iatrogenic ulnar nerve injury with this specific technique of crossed pin placement for extension-type supracondylar humerus fractures was extremely low in this series. A single case of transient ulnar sensory neuropraxia occurred. Our series demonstrates that crossed pin fixation can be performed safely and reliably and is an appropriate treatment option for unstable supracondylar humerus fractures.