Arthroscopically assisted percutaneous osteosynthesis of displaced transverse patellar fractures with figure-eight wiring through paired cannulated screws.

Introduction: For treatment of displaced transverse patellar fractures, open reduction and internal fixation is the standard reconstructive method. The role of percutaneous osteosynthesis is still unclear and worth of further investigation. Our hypothesis is that satisfactory reduction and rigid fixation is possible for the treatment of displaced transverse patellar fractures with some percutaneous techniques. Here, we present and evaluate a minimally invasive technique for these patellar fractures.

Patients And Methods: This is a retrospective study. Twenty-one patients with 21 transverse patellar fractures were treated with our percutaneous technique in acute phase. The minimally invasive surgery was achieved by closed reduction and fixation with modified Carpenter's technique, using figure-eight wiring through two parallel cannulated screws under the assistance of arthroscopy and fluoroscopy. The patients were followed up to an average of 38.8 months (range 26-48). Main outcome measurements included radiographic assessment, range of motion, Lysholm scores, complications, and reoperations.

Results: Radiographically, all fractures healed at a mean of 11.0 weeks (range 9-13). Mean total range of motion of knee joint was 140.1° (range 127-152). Functional assessment of Lysholm scores was 93.9 points (range 86-100). Malreduction, loss of reduction, and infection were not observed in 21 patients. Complications were three cases (14%) of hardware irritation, and needed a second operation for removal.

Conclusions: Under the control of arthroscopy and fluoroscopy, we successfully treated 21 displaced transverse patellar fractures by percutaneously osteosynthesis. This is a safe and reproducible method for transverse patellar fractures. However, it is not indicated for severely comminuted fractures.