Functional Impact at 12 Months Post-op of Posterior Cruciate Ligament Conservation During Robotic-assisted Surgery (MAKO) for Total Knee Replacement.

Centre Hospitalier Universitaire de Nīmes300 enrolled

Overview

Studies have been made on the best way to do knee surgery and whether to conserve the posterior cruciate ligament or not during total knee prosthesis insertion is still under debate. However, most of these studies were made before the introduction of robotic knee surgery. It seems timely to do a study comparing these two surgical techniques: preservation versus removal of the posterior cruciate ligament in knee arthroplasty

Knee arthroplasty is a growing surgical discipline and 102,655 prostheses were fitted in France in 2019. The principle of total knee arthroplasty (TKA) is to replace a thickness of bone and cartilage whilst maintaining homogeneous tension of the capsulo-ligamentary envelope. Different designs have been developed over the years to achieve a good compromise between stability and mobility, ligament balancing being one of the major challenges of this procedure. The results of this surgery are good, but remain inferior to those of the total hip prosthesis. Around 1/5 patients operated on are dissatisfied. The posterior cruciate ligament (PCL) plays a role in the stability of the prosthetic knee, preventing anteroposterior translation and allowing femoral roll-back. It also plays a role in flexion space. However, whether or not the PCL is retained during total prosthetic knee insertion has not been shown to make any difference to clinical or functional outcomes. The proprioceptive role of mechanoreceptors in the anterior cruciate ligament (ACL) has already been demonstrated in several studies. A similar effect can thus be imagined when the PCL is conserved in TKA. Three prospective randomized studies have attempted to demonstrate this. However, those three studies did not find any significant differences in clinical or functional results. It should be noted, however, that all those studies were carried out without the use of robotics or any other means of assessing PCL preservation. Robotics have made it possible to obtain better results, as well as greater accuracy and reproducibility of the surgical procedure and better intraoperative laxity control based on the concept of functional alignment. Mechanical alignment was the first to be used during insertion of the prosthetic knee. It facilitates alignment according to the tibial and femoral mechanical axis, and better implant survival thanks to improved stress distribution. However, the patient's anatomy is not respected, leading to a certain amount of patient dissatisfaction. The concept of kinematic (or anatomic) alignment was designed to achieve greater respect for patient anatomy and ligament balancing. More recently, with the advent of navigation and robotics, the authors have described functional alignment, which optimizes TKA alignment according to residual ligament tension. Since robotic assistance provides better control of the procedure and, in particular, better preservation of PCL integrity in this surgical variant, we believe it is time to conduct a high-level evidence study comparing these two surgical techniques: preservation versus removal of the posterior cruciate ligament in knee arthroplasty. The investigators hypothesize that preserving the PCL will lead to better functional results, a better quality of life and an earlier return to activity.

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Patient scheduled for first-intention robotic-assisted total knee replacement (MAKO). * Unilateral replacement, regardless of laterality. * Patient able to answer questionnaires. * Patient willing to undergo usual 12-month follow-up. * Patient has given free and informed consent and has signed the consent form. * Patient affiliated with or benefiting from a health insurance scheme. Exclusion Criteria: * Patient with intraoperative technical impossibility of retaining PCL (flessum \> 20°, flexion stiffening \< 100°). * Previous posterior cruciate ligament surgery. * Post-traumatic gonarthrosis. * Valgus \> 185°. * Patient with septic complication. * Patient participating in another interventional trial. * Patient in an exclusion period determined by another study. * Patient under court protection, guardianship or curatorship. * Patient unable to give consent. * Patients for whom it is impossible to provide informed information. * Pregnant women

Outcomes

Primary Outcomes

Functional impact at of posterior cruciate ligament preservation in the LCP+group

Evaluated according to the FJS-12 (Forgotten Joint Score) self-questionnaire. The FJS-12 is a self-administered questionnaire consisting of 12 items. The patient is asked to rate their awareness of their artificial joint for the 12 activities. Each item is then given a score of between 0-4 on a five-point Likert scale in which : 0 - Never,1 - Almost Never, 2 - Seldom, 3 - Sometimes,4 - Mostly. The answers are then summed and divided by the number of completed items. The mean value is then multiplied by 25 to obtain the total score of 0-100. The higher scores indicating better outcomes (less awareness of the joint).

Time frame: 12 months post-surgery

Functional impact at of posterior cruciate ligament resection in the LCP-group

Time frame: 12 months post-surgery