A study in the August 2010 Journal of Arthroplasty from the Anderson Orthopedic Research Institute in Alexandria, Virginia, outlined the improvement in outcome based on the number of cases surgeons had performed with unicompartmental knee replacement. They looked at 445 consecutive minimally invasive unicompartmental knee replacements performed at one institution. At a mean of 3.25 years, 26 knees required revision yielding an overall revision rate of 5.8 percent and survivorship at two years with revision being the endpoint of 96 percent. Both revisions and reoperations decreased over time. For the first half of the unicompartmental cases, the revision rate was 8.1 percent. For the second half of the cases, the revision rate dropped down to 5.4 percent. This study demonstrates that despite improvement in technique, unicompartmental knee replacement is more difficult to perform than total knee arthroplasty, and therefore the number of procedures performed by a physician can have a direct impact on the outcome of this procedure.
— William P. Barrett, MD