Posterior-stabilized and cruciate-retaining total knee replacement - A randomized study

A randomized controlled study was done to compare the clinical, radiographi c, and quality of life outcomes between posterior-stabilized and cruciate-r etaining primary total knee implants. One hundred forty-three patients were enrolled in the study. Patients ranged in age from 57 to 89 years, had a p rimary diagnosis of osteoarthritis, and an intact functioning posterior cru ciate ligament. Patients were excluded if they had a flexion contracture gr eater than 15 degrees, a varus deformity greater than 20 degrees, or a valg us deformity greater than 15 degrees. Patients were randomized to one of tw o study groups, posterior-stabilized AMK total knee implants (76 patients) or cruciate-retaining AMK total knee implants (67 patients). One hundred ei ght patients have had a minimum 2-year followup including 57 patients in th e posterior-stabilized group and 51 patients in the cruciate-retaining grou p. Seventy-three patients have had a minimum 3-year followup including 37 p atients in the posterior stabilized group and 36 patients in the cruciate-r etaining group. The overall total Knee Society clinical rating score at 2 y ears averaged 157.1 points in the posterior-stabilized group and 156.5 poin ts in the cruciate-retaining group. At 3 years, the scores averaged 156.8 p oints in the posterior-stabilized group and 163.5 points in the cruciate-re taining group. The range of motion component of the Knee Society score aver aged 113.6 degrees for the posterior-stabilized group and 108.5 degrees for the cruciate-retaining group at 2 years, and 108.3 degrees in the cruciate -retaining group and 108.5 degrees in the posterior-stabilized group. Based on the various parameters analyzed, there were no notable differences betw een the groups with a posterior-stabilized and a cruciate-retaining total k nee implant at 2 years. This trend seemed to be the same at 3 years.