Association Between Isokinetic Knee Strength and Perceived Function and Patient Satisfaction With Sports and Recreational Ability After Matrix-Induced Autologous Chondrocyte Implantation.

backgroundReturning to a sound level of activity after matrix-induced autologous chondrocyte implantation (MACI) is important to patients. Evaluating the patient's level of satisfaction with his or her sports and recreational ability is critical. PURPOSE: To investigate (1) satisfaction with sports and recreational ability after MACI and (2) the role that knee strength plays in self-reported knee function and satisfaction. STUDY

designCase-control study; Level of evidence, 3.

methodsIsokinetic knee strength was assessed in 97 patients at 1, 2, and 5 years after MACI to calculate hamstrings-quadriceps ratios and peak knee extensor and flexor torque limb symmetry indices (LSIs). The Sports and Recreation subscale of the Knee injury and Osteoarthritis Outcome Score (KOOS Sports/Rec) was completed. A satisfaction scale was used to evaluate how satisfied the patients were with their ability to return to recreational activities and their ability to participate in sport. Associations between knee strength LSI, KOOS Sports/Rec, and satisfaction with recreational and sporting activities were assessed through use of multivariable linear and logistic regression, with adjustment for confounders. Mediation analysis was conducted to assess the extent to which self-reported knee function mediated associations between strength LSI and satisfaction.

resultsSatisfaction with the ability to return to recreational activities was achieved in 82.4%, 85.6%, and 85.9% of patients at 1, 2, and 5 years, respectively, and satisfaction with sports participation was achieved in 55.7%, 73.2%, and 68.5% of patients at 1, 2, and 5 years, respectively. Knee extension torque LSIs were associated with KOOS Sports/Rec after adjustment for confounders over 1, 2, and 5 years (5-year regression coefficient, 6.0 points; 95% CI, 1.4-10.7;

conclusionKnee extensor symmetry was associated with satisfaction in recreational and sporting ability, both directly and indirectly, via self-reported sports and recreation-related knee function. Restoring strength deficits after MACI is important for achieving optimal outcomes.