Unicompartmental Knee Arthroplasty: Long-Term Success in Middle-Age and Obese Patients

The purpose of this study is to report long-term results of unicompartmental knee arthroplasty (UKA)
in general and specifically to address the results in middle-age and obese patients. One hundred
consecutive medial compartment UKAs performed in 82 patients between 1974 and 1999 were
reviewed. Survivorship analysis and Knee Society scores were compiled and stratified based on age
at the time of surgery, gender, and body habitus. Mean survivorship of the procedure was 93.7% at
5 years (95% CI 88.8–98.6%), 89.8% at 10 years (83.3–96.1%), 85.9% at 15 years (77.8–93.9%), and
80.2% at 20 years (69.5–90.9%). Females had significantly better survivorship than males at 10, 15,
and 20 years. Obese patients had better survivorship than nonobese patients at 20 years. There was
no significant difference in survivorship based on age over or under 60 at the time of surgery. The
average Knee Society knee score at most recent follow-up was 89.3 and the average function score
was 73.1. There were no significant differences in Knee Society scores among the subgroup. UKA
offers reliable long-term survival. Age less than 60 and obesity do not appear to be contraindications to
the procedure. (Journal of Surgical Orthopaedic Advances 14(2):59–63, 2005)
Key words: arthroplasty, obesity, outcome, unicompartmental