Hook plating in patella fractures

Tension band wiring is considered the standard treatment for patella fractures. However, it is limited for fractures with marginal involvement, comminution, and osteoporotic bone. Our experience indicates that these limitations can be overcome with the hook plate. We evaluated the radiographic and clinical outcomes in patients with patella fracture treated with hook plating.

We enrolled 30 patients who underwent hook plating for patella fracture at two institutions between 2013 and 2017. Fracture classification and surgical options were reviewed. Postoperative fracture gap and time to union as radiographic measurements, and complications, range of motion, and functional outcome with the Lysholm score as clinical outcomes, were evaluated retrospectively.

Nine fractures were AO/OTA 34A1, three B1, one B2, two C1, nine C2, and six C3. All were closed fractures. There were 3 cases of revision, 4 with lateral or medial marginal fracture, 9 with isolated inferior pole fracture, and 14 with comminuted fracture. The average postoperative fracture gap was 0.4 (range, 0-2.0) mm, and bone union was achieved without additional intervention. The average time to union was 11.6 (range, 7-24) weeks. There were no complications, and no extension lag except in one case (10°). The average flexion was 138.5° (range, 110-145°). For functional outcomes, the average Lysholm score was 89.5 (range, 74-95), with 13 excellent, 14 good, 3 fair, and no poor cases.

This study suggests that hook plating can result in good bone union and restored knee function in marginal or comminuted fractures of the patella.