Retention of the posterior cruciate in total knee arthroplasty.

Retention of the posterior cruciate ligament in total knee arthroplasty is discussed in biomechanical and clinical terms and the implications for design, kinematics, function, and prosthesis longevity considered. The specific roles of passive range of motion, femoral rollback, stresses on the implant-bone-prosthesis cement system, and wear are examined. The authors argue that the posterior cruciate ligament improves passive range of motion, the mechanical efficiency of the knee musculature and thus improved stairclimbing efficiency, reduces stress at the cement-bone-implant interfaces, and has little or no impact on the polyethylene wear problems.