Sliding the Medial Pin: A Safer Approach to Cross-pinning Humerus Supracondylar Fractures?

Introduction: Many methods have been described to minimize the risk of ulnar nerve injury during the insertion of a medial pin for the percutaneous pinning of pediatric supracondylar humerus fractures (SCHF). The most recent AAOS Clinical Practice Guidelines suggests that physicians might want to avoid the use of medial-entry pins due to considerations of potential injury to the ulnar nerve. However, there are circumstances whereby a cross pin configuration is required. These include cases where there is medial wall comminution or due to the obliquity of the fracture. In this study, we present a group of patients with SCHF in which the medial pin was inserted using a new technique.

Materials And Methods: This is a retrospective case series approved by the local centralized institutional review board. The medical records of all patients who underwent closed reduction and percutaneous pinning for SCHF using a new technique-the sliding method-by a single pediatric orthopedic surgeon from August 2017 till January 2018 were reviewed. Patient demographics, fracture type, operative time, postoperative Baumann's angle, postoperative lateral capitellohumeral angle, and the rate of ulnar nerve palsy were recorded.

Results: This new technique was used in a total of 35 patients. Two patients were excluded as one had multiple same limb injuries, while another had a Gustilo 3A humerus supracondylar fracture. The average patient age at the time of surgery was 6.2 years (range: 2 to 12 y). There were 22 children with Gartland grade 3 fractures, 10 with grade 2b fractures, and 1 had a flexion type fracture. The average operative time was 21 minutes (range: 7 to 58 min). The average postoperative Baumann's angle was 73.9 degrees (range: 63.8 to 79.6 degrees) and the average postoperative lateral capitellohumeral angle was 44.6 degrees (range: 31.1 to 56.8 degrees). There were no cases of ulnar nerve palsy.

Conclusions: The sliding method is a novel technique of protecting the ulnar nerve during closed reduction percutaneous pinning of SCHF.

Level Of Evidence: Level IV.