Cannulated Lag Screw Fixation of Displaced Lateral Humeral Condyle Fractures Is Associated With Lower Rates of Open Reduction and Infection Than Pin Fixation.

Abstract

BACKGROUND: Open reduction/internal fixation remains the most common way to surgically stabilize displaced pediatric lateral humeral condyle fractures, but closed reduction and internal fixation is being increasingly used. Our goal was to compare the clinical and functional results of treating displaced pediatric lateral humeral condylar fractures with traditional smooth or threaded pin fixation versus single cannulated screw fixation. METHODS: From 1998 through 2012, the lateral humeral condyle fractures of 48 patients were treated with pin fixation (22 patients, until 2006) or cannulated, partially threaded screw fixation (26 patients, from 2006 onward). In each, closed reduction with percutaneous fixation was attempted first, followed by open reduction if anatomic reduction was not achieved. For the pin and screw groups, preoperative maximum radiographic displacement averaged 8.4 mm (range, 3.8 to 18.4 mm) and 6.3 mm (range, 2.2 to 15.5 mm), respectively; follow-up averaged 4.3 months (range, 1.5 to 20 mo) and 10.3 months (range, 2 to 30 mo), respectively. We reviewed preoperative and postoperative images and all follow-up clinical examination findings; serially assessed initial displacement, Baumann and carrying angles, range of motion limitations, and clinical alignment; evaluated functional results via the system of Hardacre and colleagues; and investigated all complications. RESULTS: Open reduction was required in 73% (16/22) and 15% (4/26) of the pin and screw groups, respectively (P<0.001). All fractures were reduced to <1 mm postoperative displacement. Postoperative immobilization averaged 5.9 weeks (range, 4 to 11 wk) and 4.5 weeks (range, 3 to 8 wk) for the pin and screw groups, respectively. The only significant difference in complications was the infection rate: 5 (1 deep) in the pin group and none in the screw group (P<0.05). CONCLUSIONS: Closed reduction and percutaneous 4.5-mm lag screw fixation of displaced pediatric lateral humeral condyle fractures is safe and reliable, enabling a higher rate of closed reduction, significantly lower infection rate, and earlier mobilization than traditional pin fixation. LEVEL OF EVIDENCE: Level III-Therapeutic.