Abstract
Objective: A rupture of the patellar tendon following total knee arthroplasty (TKA) is a challenging complication. Several techniques for treatment have been reported, including cast immobilization, direct surgical repair, the use of semitendinosus grafting, hamstring tendon autogenous grafting, the use of an artificial ligament, or transplantation allografting of the bone patellar tendon-bone (BTB) or the entire extensor mechanism. We report two cases of previously infected total knee arthroplasties (TKAs) following reconstruction of the patellar tendons.
Case 1: A 73-year-old female with bilateral TKAs for osteoarthritis fell down and ruptured her right patellar tendon. The patient was referred to our institution because of bilateral knee infection from methicillin-resistant Staphylococcus aureus (MRSA) following synthetic grafting procedures. Arthrodesis of the right knee and a staged revision TKA of the left knee was performed following the resolution of the infection. There has been no recurrence of the infection to date, and the patient is ambulatory.
Case 2: A 61-year-old female with osteoarthritis, who underwent bilateral TKAs, fell down and ruptured her right medial collateral ligament and left patella tendon. The patient was referred to our institution with Staphylococcus epidermidis infection following reconstruction of her patellar tendon by a synthetic graft procedure. A staged revision TKA and a tendon reconstruction by BTB allograft was chosen as the most appropriate treatment. The patient is currently ambulatory with an extension lag of 30°, and there are no signs of recurrent infection.
Discussion: Reconstruction of the knee extension mechanism is most important for patients with a rupture of the patellar tendon following TKA; treatment options for an infected TKA with reconstruction of the extensor mechanism must be carefully considered. Resection of the patellar tendon is required in order to resolve such infection. Use of autogenous semitendinosus or gastrocnemius grafting, tendon allografting, and synthetic grafts have been reported with varying success. In our report, patellar tendon allografting with attached bone demonstrated good results as exhibited by adequate bone union and the avoidance of harvesting autogenous tissues.
