Tricon hybrid total knee arthroplasty: a review of 81 knees followed for 2 to 4 years.

The authors discuss the results of 81 total knee arthroplasties in 65 patients performed between April 1987 and April 1989 using a Tricon hybrid system, consisting of the Tricon M bio-ingrowth femoral prosthesis and the Tricon C cemented tibial component. The Tricon metal-backed patella was used until February 29, 1988, when the all-plastic Tricon C patella was introduced. With an average follow up of 24 months (range: 12 to 48), 38 arthroplasties using this hybrid system were rated as excellent (47%) and 38 were rated as good (47%). The Hospital for Special Surgery scores, which averaged 53 preoperatively, averaged 80 at the most recent follow-up assessment. At the most recent follow-up assessment, 79% of osteoarthritis patients and 56% of rheumatoid arthritis patients have no pain at rest, while 19% of osteoarthritis patients and 44% of rheumatoid arthritis patients have mild pain at rest. Sixty-four percent of osteoarthritis patients and 33% of rheumatoid arthritis patients have no pain while walking, whereas 26% of osteoarthritis patients and 56% of rheumatoid arthritis patients have mild pain while walking. Postoperative complications included fragmentation of the patella in five patients, all occurring with the metal-backed patella. Five patients also experienced petellar subluxation (two metal-backed and three all-polyethylene). One patient had deep venous thrombosis which was treated successfully by re-hospitalization and heparin therapy; one patient with chronic heart disease expired 4 days postoperatively. Use of the Tricon hybrid system has resulted in 94% of all patients having a good or excellent result an average of 24 months postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)