Characteristics of multi-ligament knee injuries accompanied with patellar tendon disruption.

Purpose: Patella tendon rupture with multi-ligament injury is a rare injury. We observed patients with patella tendon rupture (or patella inferior pole fracture) with multi-ligament injury. This study intends to inspect the mechanism of the injury and classify them.

Methods: This is a case series involving patients from two hospitals. Twelve patients who had patella tendon rupture (PTR) with multi-ligament injury were studied.

Results: The incidence of multi-ligament injury in patella tendon rupture patients found to be 13% in retrospective search. Two types of injury were observed. First type is relatively low energy injury involving ACL and patella tendon which does not involve rupture of PCL. Second type is high energy injury involving PCL and patella tendon. Treatment differed among the patients, due to severity of trauma. Two-staged operation was the basis of treatment. Patella tendon was repaired in first stage. Reconstruction of ligaments was done in second stage. The patients who had infection or stiffness did not have a second surgery.

Conclusion: Patella tendon rupture with multi-ligament injury can be classified into low energy rotational injury and high energy dashboard injury. Two-staged surgery is the basis of treatment.