The kinematic rotating hinge: biomechanics and clinical application.

The Kinematic rotating hinge offers a solution as a salvage procedure for severely deformed and unstable "end-stage" knees. Excellent short-term results in terms of pain relief can be achieved, and motion up to 130 degrees is possible, depending on the condition of the quadriceps mechanism and the extent of scarring from previous operations. Care must be taken to avoid cortical penetration, especially in cases of hinge revisions, osteoporosis, thin-walled bones, and the presence of old cement. As with any total knee arthroplasty, care must be taken to achieve optimal rotatory alignment of the tibia beneath the femur to guarantee good patellar tracking.