Use of lateral-exit crossed-pin fixation for pediatric supracondylar humeral fractures: a retrospective case series.

Surgeons have been reluctant to perform crossed-pin fixation for displaced pediatric supracondylar humeral (SCH) fractures because it carries a risk of iatrogenic ulnar nerve injury. This study aimed to introduce lateral-exit crossed-pin fixation for displaced pediatric SCH fractures and to evaluate its clinical and radiological outcomes, with a particular focus on iatrogenic ulnar nerve injuries. Children who underwent lateral-exit crossed-pin fixation for displaced SCH fractures between 2010 and 2015 were retrospectively reviewed. Lateral-exit crossed-pin fixation involved the introduction of a medial pin from the medial epicondyle, as in the conventional method, followed by pulling the pin through the lateral skin until the distal and medial aspects of the pin were just under the cortex of the medial epicondyle. The time to union and loss of fixation were assessed. Flynn's clinical criteria (cosmetic and functional factors) and complications including iatrogenic ulnar nerve injury were investigated. A total of 81 children with displaced SCH fractures were treated with lateral-exit crossed-pin fixation. All but one patient achieved union with good alignment, with an average time to union of 7.9 weeks (3.9-10.3 weeks). Only one patient exhibited cubitus varus deformity associated with loss of reduction. All patients recovered to almost their full range of motion. No case of iatrogenic ulnar nerve injury developed; however, iatrogenic radial nerve injury developed in one patient. Lateral-exit crossed-pin fixation provides sufficient stability with a lower risk of iatrogenic ulnar nerve injury in children with displaced SCH fractures. This method is an acceptable technique for crossed-pin fixation.