The Mini-invasive Medial Approach is Safe for Cross-pinning in Pediatric Supracondylar Humerus Fractures When Performed by Resident Surgeons-A Retrospective Cohort Study.

Background and purpose: In the treatment of pediatric supracondylar humerus fractures (SCHF), cross-pinning increases the risk of ulnar nerve injuries due to a misplaced medial pin. However, the extent to which the use of a mini-invasive approach medially may lead to safe cross-pinning remains unclear. Accordingly, we evaluated the safety of a mini-invasive medial approach in the hands of resident surgeons, who most commonly perform surgery on these patients.

Methods: We retrospectively analyzed iatrogenic injury rate to the ulnar nerve in children operated between 2017 and 2021. Patient, fracture, and treatment details were collected from medical records and followed a predefined protocol. 211 children with an extension-type SCHF, who were treated with an open or closed reduction before pinning, were identified. Patients with preoperative nerve injuries, concurrently operated fracture in the same arm, pin configurations other than 2 or 3 crossed pins, or surgeries conducted by an attending surgeon, were excluded. Our institutional practice of cross-pinning with a mini-invasive medial approach to a semiflexed elbow was performed by residents in orthopaedic surgery in 167 patients.

Results: No iatrogenic ulnar nerve motor injuries were found. Three out of 167 patients experienced transient sensory changes to the ulnar nerve, all resolving within the first week. In every procedure, the lead surgeon was a resident.

Conclusion: Our results indicate that the mini-invasive medial approach is safe in the hands of resident surgeons for cross-pinning in pediatric SCHF. This finding suggests that iatrogenic ulnar nerve injuries may be prevented by performing mini-invasive medial pinning in a semiflexed elbow.