As population shifts occur in age and demographics, our goals for restoration of function have grown in knee arthroplasty. With this focus has come the advent of high-flexion components whose designs have sought to advance the recreation of normal knee kinematics. A review of the theory, mechanics, and documented performance is fundamental in the determination of their worth. High-flexion designs aim at the restoration of axial femoral-tibial rotations and posterior femoral translation for efficacy. In cadaver studies, these systems have reproduced 80-90% of normal posterior femoral translation and improved kinematic curves. In addition, kinematic improvement has been documented when studied in vivo. When the results between standard and high-flexion systems are compared, three retrospective studies have documented significant increases in flexion while two prospective studies have found no significant difference in flexion. Functional scores have not shown statistically significant improvement. Multiple systems have been developed using combinations of design changes to improve the biomechanics of arthroplasty. Laboratory and clinical studies have evaluated these systems. Kinematic improvement is documented in the laboratory setting and in the clinical setting; however, the results of clinical studies are equivocal in regards to functional improvement.
ASJC Scopus subject areas
- Orthopedics and Sports Medicine