Pin and Wire System Fixation for the Treatment of Comminuted Patella Fractures

We describe the wiring technique and evaluate the radiographic and clinical outcomes of treatment with a pin and wire system (PWS) for comminuted patella fractures. From June 2013 to October 2018, 33 patients with comminuted patella fractures were treated using a PWS. Open reduction and internal fixation was performed with multiple pins and a wire. All patients were allowed full weight bearing without a brace. Radiographs were obtained to evaluate bone union, implant breakage, back-out of pins, and intra-articular gaps and step-off. Clinical outcomes and postoperative complications were assessed at final follow-up examination. All fractures were united. Thirteen cable wires in 13 patients were partially broken without displacement of fracture at an average of 7.4 months (range, 1-19 months) postoperatively. The average preoperative, postoperative, and final follow-up intra-articular gap and step-off were 11.7 mm, 0.5 mm, and 0.03 mm and 6.6 mm, 0.4 mm, and 0.2 mm, respectively. The average postoperative pin displacement was 0.1 mm (range, 0-0.8 mm). Deep infection was not observed after the surgery. The implant removal rate was 21% (7 of 33). Among these, the symptomatic implant removal rate was 9% (3 of 33). Additionally, 3 of 7 patients with implant removal had broken wires. The average flexion and extension of knee joints were 139.7° (range, 120°-150°) and -0.9° (range, -10° to 0°), respectively. A PWS prevents back-out of the pins and reduces intra-articular gaps and step-off distances to acceptable levels, even if the cable wire is partially broken. Therefore, a PWS is a good treatment option for comminuted patella fractures. [Orthopedics. 2023;46(5):291-296.].