RESUMEN
Recognizing and providing effective treatment for polyethylene failure after total knee arthroplasty (TKA) are challenging problems. The range of presenting symptoms and the usefulness of diagnostic tests are examined, and the outcome of surgical treatment of patients with tibial polyethylene failure is reported. From a consecutive series of 209 Primary Porous-Coated Anatomic (Howmedica, Rutherford, NJ) TKAs performed between 1984 and 1987, 18 cases (9%) required revision surgery. No patient experienced polyethylene failure prior to 48 months, and the average time to revision was 81 months after index TKA. The follow-up period after revision surgery averaged 24 months. Symptoms began after a period of good function, and preceded revision by an average of 8 months. The most common presenting symptom was swelling (89%), followed by stiffness (72%), pain (67%), and clicking (38%) or instability (22%). Single leg standing anteroposterior radiographs were most effective, demonstrating polyethylene failure by a change to increasing varus and narrowing of the polyethylene space in 16 of 18 cases. Arthroscopic evaluation confirmed the diagnosis in two cases. Five cases required tibial tubercle osteotomy for exposure, and 15 required complete synovectomy. Exchange of the damaged heat-pressed polyethylene insert with a machined insert was performed in 14 cases, exchange plus tibial tray revision in 3 cases, and complete knee revision in 1 case. Revision surgery successfully restored pain-free function and improved range of motion in 16 of 18 cases. Survivorship analysis showed an 11% failure rate at 8 years after index procedure. Regular follow-up evaluation for the Primary Porous-Coated Anatomic TKA is suggested.
