Improved Patellar Stiffness Proves Benefits of Tensioned MPFL Reconstruction

In many orthopaedic contexts, post-procedure stiffness is a complication to be avoided. But when it comes to reconstructing the medial patellofemoral ligament (MPFL) to treat recurrent patellar dislocation, stiffness of the patella is, to borrow Hamlet’s phrasing, “a consummation devoutly to be wished.”

In the April 6, 2016 edition of The Journal of Bone & Joint Surgery, Kumahashi et al. report on 17 knees with recurrent patellar dislocation that underwent MPFL reconstruction using an autograft semitendinosus tendon and an interference screw for precise graft tensioning. Medial patellar stiffness was significantly improved three months after surgery, and the reconstructions achieved the normal stiffness levels found in reference knees (n=64) after six months. Moreover, medial and lateral patellar stiffness was found to be well balanced by six months and for up to two years postoperatively.

The authors describe their intraoperative graft-tensioning technique in detail. They measured patellar stiffness (in N/mm) using a Patella Stability Tester (Kishi Engineering, Izumo, Japan) preoperatively and every three months after surgery up to two years. In addition, postoperative radiographic findings and Kujala and Lysholm scores were significantly improved at the time of the latest follow-up relative to preoperative radiographic and clinical evaluations.