Unicompartmental knee arthroplasty. Ten- to 13-year follow-up study.

In the past decade, two concepts have caused considerable controversy in orthopedic surgery of the knee. Some orthopedic centers contend that osteotomy of the tibia is the procedure of choice for unicompartmental gonarthrosis of the knee and resist the concept of unicompartmental arthroplasty. The other concept is that if unicompartmental arthroplasty is necessary, the entire joint should be replaced, since the uninvolved compartment may develop arthritis in the future. This concept is illogical and contrary to the basic orthopedic principle of preserving normal structures whenever possible. It is obvious that joint replacements may not last the life of the patient and the need for revision must be considered; therefore, the original procedure should preserve as much bone stock as possible. The purposes of this review of unicompartmental replacement are to resolve these questions with data on long-term results of unicompartmental arthroplasty compared with data on high tibial osteotomy, to evaluate the cause of failures, and to improve future results. Eighty-seven consecutive unicompartmental arthroplasties were performed between November 1972 and April 1976. There were 60 knees available for study, with a minimum ten-year (average, 11-year) follow-up period. The results were evaluated using the Hospital for Special Surgery rating system, with 30 excellent, eight good, four fair, and 18 poor results. Seventy percent of the patients had satisfactory results, and pain relief was accomplished in 86.6% of patients. Of the 21 failures, the majority were due to material or technical problems and improper selection of the patients.(ABSTRACT TRUNCATED AT 250 WORDS)