Reestablishment of the Posterior Stability After the Posterior Cruciate Ligament-Released Cruciate Retaining Total Knee Arthroplasty.

PURPOSE: The cruciate retaining (CR) design was developed to obtain knee stability with the natural posterior cruciate ligament (PCL) in total knee arthroplasty (TKA). However, the preservation of the PCL can limit knee exposure and increase the technical challenge during the procedure. Knee exposure is easily achieved under the released PCL, and we hypothesized that the PCL naturally repairs after release, thus re-establishing the posterior stability. Accordingly, the objective of this study was to evaluate the varying of the posterior stability after the PCL-released CR TKA over time. METHODS: Eight consecutive patients received the CR TKA in which the entire PCL was subperiostealy released at its femoral insertion. Thereafter, the patients were examined with the Knee Society Score, the posterior drawer examination, and the knee ligament arthrometer postoperatively. RESULTS: Once the PCL was released, the tibia was easily subluxated, and the knee was clearly exposed intraoperatively. However, the posterior stability significantly improved with time postoperatively. We also had confirmed the reestablishment of the PCL directly at revision TKAs, one case of which is shown. CONCLUSION: The reestablishment of the posterior stability after the PCL-released CR TKA was demonstrated. This procedure to release the entire PCL subperiostealy is recommended as a means of facilitating CR TKA.