The Effect of Sacrificing the Posterior Cruciate Ligament in Total Knee Arthroplasties That Use a Highly Congruent Polyethylene Component

Abstract

Background: There is continued debate regarding retention versus sacrificing of the posterior cruciate ligament (PCL) in total knee arthroplasty (TKA). We sought to determine if there was a difference in range of motion (ROM) after TKA between patients with PCL sacrifice versus PCL retention when using a highly congruent polyethylene insert.

Methods: We conducted an Institutional Review Board approved retrospective study of consecutive patients receiving TKA using the same implant with a highly congruent polyethylene component implanted by one surgeon from November 2013 to January 2016. Patients were placed in 2 groups based on whether the PCL was intact or released at the time of surgery. Patient charts were reviewed for age, body mass index, PCL status at surgery (incompetent, kept intact, or released), and preoperative/postoperative knee ROM.

Results: Both groups were similar in average age (60.5 vs 60.6, respectively) and body mass index (33.3 vs 32.6, respectively). Postoperative tibial slope (5.5° PCL release, 6.6° PCL retained, P = .028) was the only alignment variable reaching significance; all other alignment and motion variables were similar.

Conclusion: Results indicate that the PCL can be successfully retained with the use of a congruent bearing design, with no evident limitation in postoperative ROM or loss of stability due to the bearing in comparison to patients who undergo PCL release.

Keywords: highly congruent polyethylene component; knee balancing; posterior cruciate ligament retention; posterior cruciate ligament sacrifice; total knee arthroplasty.