BACKGROUND: There is little information on the feasibility of
computer navigation when using a minimally invasive approach for total knee
arthroplasty, during which the anatomic landmarks for registration may be
obscured. The purpose of the present study was to determine the radiographic
accuracy of this technique and to compare the rate of functional recovery
between patients who underwent computer-assisted minimally invasive
arthroplasty and those who underwent conventional total knee arthroplasty.
METHODS: One hundred and eight consecutive patients were randomized
to undergo computer-assisted minimally invasive total knee arthroplasty or
conventional total knee arthroplasty. Perioperative pain management was
standardized. The clinical parameters, long-leg radiographs, and functional
assessment scores were evaluated for six months postoperatively.
RESULTS: Patients who underwent computer-assisted minimally invasive
total knee arthroplasty had a significantly longer operative time (by a mean
of twenty-four minutes) and a significantly shorter inpatient stay (3.3
compared with 4.5 days) in comparison with those who underwent conventional
arthroplasty (p 0.001). Significantly more patients in the computer-assisted
minimally invasive total knee arthroplasty group were able to walk
independently for more than thirty minutes at one month (p = 0.04). The
percentage of patients with a coronal tibiofemoral angle within ±3°
of the ideal was 92% for the computer-assisted minimally invasive total knee
arthroplasty group, compared with 68% for the conventional total knee
arthroplasty group (p = 0.003).
CONCLUSIONS: Although specific clinical parameters reflect an early
increased rate of functional recovery in association with computer-assisted
minimally invasive total knee arthroplasty within the first postoperative
month, the main advantage of this technique over conventional total knee
arthroplasty is improved postoperative radiographic alignment without
increased short-term complications.
LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions
to Authors for a complete description of levels of evidence.