Iatrogenic ulnar nerve injury after pin fixation and after antegrade nailing of supracondylar humeral fractures in children

Background and purpose

Ulnar nerve injury may occur after pinning of supracondylar fractures in children. We describe the outcome and compare the rates of iatrogenic injuries to the ulnar nerve in a consecutive series of displaced supracondylar humeral fractures in children treated with either crossed pinning or antegrade nailing.

Methods

Medical charts of all children sustaining this fracture treated at our department between 1994 and 2009 were retrospectively reviewed regarding the mode of treatment, demographic data including age and sex, the time until implant removal, the outcome, and the rate of ulnar nerve injuries.

Results

503 children (55% boys) with an average age of 6.5 years sustained a type-II, type-III, or type-IV supracondylar fracture. Of those, 440 children were included in the study. Antegrade nailing was performed in 264 (60%) of the children, and the others were treated with crossed pins. Iatrogenic ulnar nerve injury occurred in 0.4% of the children treated with antegrade nailing and in 15% of the children treated with crossed pinning. After median 3 (1.6–12) years of follow-up, the clinical outcome was good and similar between the 2 groups.

Interpretation

Intramedullary antegrade nailing of displaced supracondylar humeral fractures can be considered an adequate and safe alternative to the widely performed crossed K-wire fixation. The risk of iatrogenic nerve injury after antegrade nailing is small compared to that after crossed pinning.In children, supracondylar fractures are the most common type of fracture of the elbow region (Omid et al. 2008). Boys usually have a higher incidence of this type of fracture but some recent reports in the literature describe rising rates in girls (Cheng et al. 2001). Most of the patients are 5–7 years old (Davis et al. 2000, Omid et al. 2008, Zamzam and Bakarman 2009). At this age, the potential for fracture remodeling decreases; therefore, malreduction may lead to persistent deformity (Wessel et al. 2003).In displaced fractures, the most common operative treatment is closed reduction and pin fixation. Different techniques have been reported, but crossed pinning with postoperative immobilization is the preferred technique (Brauer et al. 2007, Kocher et al. 2007, Zamzam and Bakarman 2009). Iatrogenic injury to the ulnar nerve has been described in up to 20% of the cases treated with crossed pinning (Lyons et al. 1998). In addition, radial pinning may damage the radial and anterior interosseous nerve (Brauer et al. 2007, Kocher et al. 2007, Omid et al. 2008).In 1990, a technique with antegrade nailing for supracondylar fractures was first described by Prevot et al. (1990). Schaffer et al. (2007) and Weinberg et al. (2003) treated 60 and 50 children with this technique and reported no iatrogenic injuries to the ulnar nerve.We determined the outcome and compared the rates of iatrogenic injuries to the ulnar nerve in a consecutive series of displaced supracondylar humeral fractures in children treated with either crossed pinning or antegrade nailing.