Periprosthetic patellar fracture fixation using suture anchors

Treatment of type II periprosthetic patellar fractures presents difficulties in decision-making particularly when displacement is greater than 10 mm. Poor results have been reported with internal fixation, whereas conservative management has been associated with a high incidence of extensor lag. This article reports a patient with a displaced type II patellar fracture following total knee arthroplasty. One month after undergoing total knee arthroplasty, a 72-year-old man presented to the emergency department with difficulty walking. Physical examination revealed an extensor lag with a palpable defect in the extensor mechanism. Radiographs showed a transverse, comminuted fracture through the distal third of the patella with a separation of approximately 15 mm. The patient underwent surgery, at which time the patellar component was found to be intact and well fixed to the proximal fragment. Three suture anchors were introduced into the proximal fragment through the fracture site. Tunnels were drilled in the distal fragment (through the fracture gap) corresponding to the location of the anchors; the sutures were threaded through these tunnels. Anatomical reduction was achieved with towel clips, and the sutures were tied at the distal pole. After the knots were tied, anatomical reduction was maintained, and the sutures were additionally used as cerclage around the patella. One year postoperatively, the fracture showed union, and the patient had good range of motion with no extensor lag. No patellar subluxation, avascular necrosis, or refracture occurred.