Mechanism of Anterior Impingement Damage in Total Knee Arthroplasty

Total knee replacements (TKR) are typically designed to accommodate 10° to 15° of hyperextension. However, many retrieved polyethylene tibial inserts, both from posterior cruciate ligament (PCL)-retaining and PCL-substituting TKRs, exhibit a high incidence of anterior wear on the tibial eminence or post. The mechanism for this anterior wear is not well understood. In addition, studies with fluoroscopic analysis have shown that some TKRs hyperextend during daily activities more than previously thought 1,2.