Thirty-seven patients with unicompartmental osteoarthritis were treated
by replacement arthroplasty using the Marmor modular prosthesis and each
patient was followed for at least two years. Despite rigid preoperative
criteria for the selection of cases, the over-all results were definitely
inferior to those seen after either bicompartmental or tricompartmental
replacement arthroplasty. Complications included recurrent pain and
degeneration of the other compartment, often associated with abrasion of
the remaining cartilaginous surfaces caused by polyethylene particles.
There was also more settling of the tibial component in these patients than
in patients treated by bicompartmental replacement arthroplasty. Because of
these findings, we no longer use unicompartmental replacement of the medial
side of the knee. The results after the three lateral compartment
replacements, on the other hand, were good, and use of this procedure for
post-traumatic arthritis is still under investigation.