The use of a tantalum-based Augmentation Patella in patients with a previous patellectomy.

Patients with previous patellectomies for anterior knee pain syndrome, can remain symptomatic and develop osteoarthrosis or instability. We report our experience of the use of a novel implant to substitute for the absent native patella. Seven patients, with previous patellectomies, were treated with the Augmentation Patella (Zimmer, Allendale, USA). This implant was sutured to the patellar tendon, as part of a patello-femoral joint replacement (four cases) or total knee replacement (three cases). In three patients, the implant loosened and failed within 15 months. Two patients remained symptomatic despite solid fixation. One patient developed wound complications due to the bulk of the implant, and the procedure was abandoned in one patient as wound closure was not possible. The results of this implant in our patients with previous patellectomies have been disappointing. Previous studies where this implant has been used, have also shown high loosening and failure rates. We do not recommend its use to substitute for the absent patella.