Total knee arthroplasty designed to accommodate the presence or absence of the posterior cruciate ligament.

Melinda K Harman,Stephanie J Bonin,Chris J Leslie,Scott A Banks,W Andrew Hodge

doi:10.1155/2014/178156

Abstract

Evidence for selecting the same total knee arthroplasty prosthesis whether the posterior cruciate ligament (PCL) is retained or resected is rarely documented. This study reports prospective midterm clinical, radiographic, and functional outcomes of a fixed-bearing design implanted using two different surgical techniques. The PCL was completely retained in 116 knees and completely resected in 43 knees. For the entire cohort, clinical knee (96 ± 7) and function (92 ± 13) scores and radiographic outcomes were good to excellent for 84% of patients after 5–10 years in vivo. Range of motion averaged 124° ± 9°, with 126 knees exhibiting ≥120° flexion. Small differences in average knee flexion and function scores were noted, with the PCL-resected group exhibiting an average of 5° more flexion but an average function score that was 7 points lower compared to the PCL-retained group. Fluoroscopic analysis of 33 knees revealed stable tibiofemoral translations. This study demonstrates that a TKA articular design with progressive congruency in the lateral compartment can provide for femoral condyle rollback in maximal flexion activities and achieve good clinical and functional performance in patients with PCL-retained and PCL-resected TKA. This TKA design proved suitable for use with either surgical technique, providing surgeons with the choice of maintaining or sacrificing the PCL.

Highlights

Contemporary total knee arthroplasty (TKA) provides reliable pain relief and restoration of moderate function for patients suffering from severe joint degeneration
A total of 134 patients (159 TKA) met the inclusion criteria and were willing to participate in the study, including 116 of 193 (60%) TKA implanted by a surgeon who preserved the posterior cruciate ligament (PCL) with a bone block and 43 of 58 (74%) TKA implanted by a surgeon who completely resected the PCL
Stability scores reported within the KSS knee score were perfect (25 points) for 97% and 86% of the TKA in the PCL-retained and PCL-resected groups, respectively

Summary

Introduction

Contemporary total knee arthroplasty (TKA) provides reliable pain relief and restoration of moderate function for patients suffering from severe joint degeneration. Excessive AP motion in well-aligned prostheses occurs with the femur sliding anterior on the tibia in flexion and posterior in extension, resulting in limited femoral rollback and the potential of bony impingement between the femur bone and posterior rim of the tibial insert [5, 14,15,16]. This instability appears to result from the loss of the knee’s natural intrinsic stabilizing structures after TKA, including one or both of the cruciate ligaments and the menisci [17]. Controlling AP translation of the femur, in the presence or absence of the posterior cruciate ligament (PCL), is often cited as a means for achieving optimal function in modern TKA designs [5, 16, 18,19,20,21,22,23,24,25,26]

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