Background: The operative treatment of medial compartment knee
arthritis is controversial. The purpose of the present study was to report the
experience of a single surgeon with the UniSpacer arthroplasty for the
treatment of isolated medial compartment arthritis of the knee.
Methods: From April 2002 through November 2002, thirty-seven
UniSpacer arthroplasties were performed in thirty-four patients for the
treatment of arthritis that primarily involved the medial compartment of the
knee. The Ahlbäck radiographic evaluation scale was used to grade the
severity of arthritis; the mean preoperative score was 2.6 points for the
medial compartment and 0.5 point for both the lateral and patellofemoral
compartments. The study group included eighteen women (nineteen knees) and
sixteen men (eighteen knees) who had a mean age of fifty-five years (range,
forty-two to seventy-five years) at the time of surgery. Twelve patients had
had a previous arthroscopic meniscectomy. The mean preoperative Knee Society
function score was 60 points (range, 40 to 80 points), and the mean
preoperative Knee Society objective score was 62 points (range, 40 to 76
Results: After a mean duration of follow-up of twenty-six months
(range, twenty-four to twenty-nine months), there were no excellent, ten good,
fifteen fair, and twelve poor results. The mean postoperative total function
score was 69 points (range, 40 to 82 points), and the mean Knee Society
objective score was 72 points (range, 45 to 88 points). Six of the twelve poor
results were in knees that had dislocation of the UniSpacer. All twelve knees
were revised to a total knee arthroplasty.
Conclusions: On the basis of this experience, we do not recommend
UniSpacer arthroplasty for the treatment of degenerative arthritis of the
medial compartment of the knee.
Level of Evidence: Therapeutic Level IV. See Instructions
to Authors for a complete description of levels of evidence.