Isokinetic strength testing of minimally invasive total knee arthroplasty recovery

Fifty patients underwent isokinetic muscle strength testing before surgery and at 6 weeks, 3 months, 6 months, and 1 year after unilateral total knee arthroplasty using the minisubvastus surgical technique. Quadriceps muscle strength returned to preoperative levels by 3 months postoperatively and was 17% stronger at 6 months and 30% stronger at 1 year than preoperative levels (P < .05). At 1 year, the quadriceps strength of the involved knee was equivalent to that of the uninvolved knee (P = .81). When the entire study population was subdivided by age, weight, sex, and the presence of arthritis in the uninvolved knee, each subgroup still had equivalent quadriceps strength between the involved and uninvolved knees. This prospective study demonstrated that the minisubvastus total knee arthroplasty technique led to a more rapid and more complete recovery of muscle strength than has been previously demonstrated after total knee arthroplasty with a medial parapatellar arthrotomy.