Kinematics of posterior cruciate ligament-retaining and -substituting total knee arthroplasty

Abstract

We performed a prospective, randomised trial of 44 patients to compare the functional outcomes of a posterior-cruciate-ligament-retaining and posterior-cruciate-ligament-substituting total knee arthroplasty, and to gain a better understanding of the in vivo kinematic behaviour of both devices. At follow-up at five years, no statistically significant differences were found in the clinical outcome measurements for either design. The prevalence of radiolucent lines and the survivorship were the same. In a subgroup of 15 knees, additional image-intensifier analysis in the horizontal and sagittal planes was performed during step-up and lunge activity. Our analysis revealed striking differences. Lunge activity showed a mean posterior displacement of both medial and lateral tibiofemoral contact areas (roll-back) which was greater and more consistent in the cruciate-substituting than in the cruciate-retaining group (medial p < 0.0001, lateral p = 0.011). The amount of posterior displacement could predict the maximum flexion which could be achieved (p = 0.018). Forward displacement of the tibiofemoral contact area in flexion during stair activity was seen more in the cruciate-retaining than in the cruciate-substituting group. This was attributed mainly to insufficiency of the posterior cruciate ligament and partially to that of the anterior cruciate ligament. We concluded that, despite similar clinical outcomes, there are significant kinematic differences between cruciate-retaining and cruciate-substituting arthroplasties.

Is There a Gold Standard for TKA Tibial Component Rotational Alignment?

“…Studies on tibial internal-external rotation after TKA have reported mixed findings, with some researchers noting decreases [45] and others reporting no change [12]. We observed an increase in tibial rotation, but our average value for the native condition is similar to what Siston et al [45] reported for osteoarthritic knees (4.9°± 4.1°) and nearly identical to what Victor et al [52] observed for TKA knees (10.8°).…”

Comparison of Total Knee Arthroplasty With Highly Congruent Anterior-stabilized Bearings versus a Cruciate-retaining Design

“…PCL substitution in primary TKA has traditionally relied on a cam and post (cam-post) mechanism in the form of a posterior-stabilized (PS) design. Short-and long-term evaluations of PS and CR knees have failed to show clinically significant differences in their outcomes [2,11,12,[17][18][19][20][21].…”

In Vivo Kinematics after a Cruciate-substituting TKA

“…Also, in vivo kinematic studies involving patients undergoing TKA have documented reverse rotational patterns [2,10] and lateral condylar liftoff [13,21,34,37]. There is evidence these abnormal kinematic patterns lead to decreased ROM [3,11,38]. In addition, these abnormal kinematic patterns possibly relate to inferior functional performance of daily activities by patients undergoing TKA.…”

“…In the spectrum of kinematic abnormalities, a couple studies suggest subjects having a posterior stabilized (PS) TKA have less abnormal knee kinematics in deeper flexion and greater flexion than subjects having a posterior cruciate-retaining (PCR) TKA [8,38]. However, measurement in weightbearing conditions typically reduces the observed ROM [11].…”