Posterior polyethylene wear in posterior cruciate ligament-retaining total knee arthroplasty. A case study.

Controversy over whether to retain the posterior cruciate ligament (PCL) during primary total knee arthroplasty continues. Both the retaining and substituting designs have their respective advantages and disadvantages. In order to capitalize on the advantages of the PCL retaining design, precise techniques in ligament balancing are required. An incorrectly tensioned PCL--too tight or too loose--may exaggerate the disadvantages of the retaining design and lead to early catastrophic failure. Three cases of early catastrophic posterior wear are presented. Although no definite documentation of excessive PCL tension is available, the authors feel that this may have had a significant role in the etiology of this wear pattern. Possible causes of incorrect PCL tension as well as intraoperative techniques to balance the PCL properly are discussed.