Arthroscopic-assisted percutaneous screw fixation of select patellar fractures.

PURPOSE: To describe a technique of arthroscopic-assisted reduction and percutaneous cannulated screw fixation for displaced patellar fractures and to present the results of 5 cases.

TYPE OF STUDY: Case series.

METHODS: Five patients (3 male, 2 female) with displaced patellar fractures treated with an arthroscopic-assisted reduction and percutaneous cannulated screw fixation were prospectively analyzed. The mean age was 53 years (range, 27 to 74 years). All fractures were fixed with at least 2 4-mm cannulated screws under arthroscopic visualization. Cerclage wiring through the cannulated screws was necessary in 2 patients with osteopenic bone. Controlled passive range of motion exercises were started on the first postoperative day. Full weight bearing with an immobilizer-type brace was allowed as tolerated. The mean follow-up was 28 months (range, 24 to 35 months). The patients were evaluated with Lysholm II scores, clinical examination, knee range of motion, thigh circumference measurements, and radiographs.

RESULTS: All fractures healed uneventfully. The mean Lysholm II score was 84.8 (range, 75-96). All but 1 patient regained full knee range of motion. A mean quadriceps atrophy of 0.8 cm compared with the contralateral side was seen in unilateral cases. There was no implant failure or infection.

CONCLUSIONS: Arthroscopic-assisted reduction and percutaneous cannulated screw fixation is appropriate for displaced transverse patellar fractures without major separation and comminution. Longitudinal or oblique fractures, even if there are more than 2 major fragments, are amenable to arthroscopic techniques, providing the fragments are large enough to be fixed with screws. This technique is minimally invasive and does not disturb the vascular supply of patella. It allows clear visualization of the reduction and stability of the fracture, and facilitates early postoperative range of motion exercises. This method is not suitable for highly comminuted fractures or transverse fractures with major separation that are accompanied by rupture of the extensor mechanism.