Patellar Tendon Rupture After Total Knee Arthroplasty

Abstract

Patellar tendon disruption is a catastrophic complication of TKA. Although this complication is rare, it rivals infection as the most devastating outcome after TKA.Recognition of the risk factors for patellar tendon disruption and a focus on preventive efforts through meticulous surgical exposure and technique are paramount. Avoiding disruption of the patellar tendon can be accomplished by paying close attention to appropriate knowledge of patients’ medical and surgical risk factors. The variety of management options available highlights the lack of consistently satisfactory results from any single treatment method.When disruption of the patellar tendon does occur, direct primary repair should be the first line of treatment for reconstruction.Direct repair should be evaluated intraoperatively with direct visualization under stress to determine the strength of the repair and whether augmentation is warranted. Autogenous graft augmentation after primary repair of a disrupted patellar tendon has been used for years by providing healthy collagen tissue to strengthen the repair tissue. Its use is appropriate in patients who may have weak connective tissue from systemic disease, elderly patients with tissues that have been devascularized by previous operations, infected TKA, exposed prosthesis, and patients who have had a previous patellectomy.

Summary & Conclusion Allograft augmentation of a disrupted patellar tendon in the setting of a TKA has gained popularity. The goal for allograft augmentation is to restore the tissue of the extensor mechanism in a setting where the tissue is mechanically insufficient and structurally inadequate for the demands of knee joint function. Achilles tendon allografts and extensor mechanism allografts have been used successfully to restore a disrupted patellar tendon.Modifications to the originally described technique including more vigorous tensioning of the graft and protected flexion postoperatively have resulted in improved functional outcomes, with no compromise to knee flexion. Gastrocnemius rotational muscle flaps showed satisfactory results especially if there’s extensive soft-tissue loss leading to prosthesis to be uncovered and possible infection. The use of synthetic materials for reconstruction of patellar tendon disruptions offers promise, but more data are needed to fully evaluate the useof these materials. The following algorithm provides a check list for orthopaedic surgeons to follow for determination of the best operative technique and tissue type to be used for treatment of patients with patellar tendon disruption associated with a total knee arthroplasty.