Mechanically or Kinematically Aligned Total Knee Prosthesis

Official title

Mechanically or Kinematically Aligned Total Knee Prosthesis: Prospective and Comparative Study of Clinical, Stereoradiographic, and Biomechanical Results

Overview

The mechanical alignment technique (Mechanical Alignment - MA) of a total knee prosthesis (TKA) was developed with the aim of making the installation of a TKA simple and reproducible, and that the prosthetic biomechanics are acceptable, thus promoting good longevity of implants. This is a technique that does not aim to restore the constitutional anatomy of the knee; bone cuts are systematically made at fixed angles, in the 3 planes of space, in relation to the mechanical axes of the long bones (femur and tibia). This non-personalized implantation technique therefore systematically alters the anatomy, laxity and kinematics of the knee, causing up to 50% of residual symptoms after prosthetic implantation and 20% of dissatisfied patients. In order to improve the clinical results of TKA, a new, more personalized and physiological technique was developed in 2007, called Kinematic Alignment (KA). This technique aims to restore the pre-arthritic anatomy, unique to each knee. Patients with severe constitutional deformity of the lower limb therefore retain this deformity after kinematic prosthetic replacement. The impact of the alignment technique on the biomechanics of the prosthetic knee remains poorly described. The main objective of this study is therefore to compare knee biomechanics between mechanical TKA and kinematic TKA.

Interventions

• Device kinematic knee prosthesis
  Patients with a kinematically aligned total knee prosthesis and having a post-operative follow-up consultation within at least 1 year after their surgery are consecutively pre-selected according to the eligibility criteria.
• Device biomechanic knee prosthesis
  A group of patients with a mechanically aligned TKA and scheduled for a follow-up consultation 1 year after surgery will be identified to be matched on the aforementioned criteria (sex, age, BMI).

Primary outcome measures

• Biomechanical parameters of knee : spatiotemporal parameters [Time frame: One year after surgery]
• Biomechanical parameters of knee : Kinematic parameters in the 3 planes of space [Time frame: One year after surgery]
• Biomechanical parameters of knee : joint moments [Time frame: One year after surgery]
• Biomechanical parameters of knee : force [Time frame: One year after surgery]
• Biomechanical parameters of knee : lever arms [Time frame: One year after surgery]
• Symmetry index between the operated limb and the healthy controlateral limb [Time frame: One year after surgery]

Secondary outcome measures (12)

• Clinical results : Patient-Reported Outcome Measures: Functional score (OXFORD scale) [Time frame: One year after surgery]
• Clinical results : Patient-Reported Outcome Measures: joint perception score [Time frame: One year after surgery]
• Clinical results : Patient-Reported Outcome Measures: pain [Time frame: One year after surgery]
• Clinical results : Patient satisfaction [Time frame: One year after surgery]
• Clinical results : range of mobility of the prosthetic knee [Time frame: One year after surgery]
• Clinical results : complication rate [Time frame: One year after surgery]
• Imaging results : EOS 3D, alignement of the lower limb [Time frame: One year after surgery]
• Imaging results : EOS 3D, orientation of the implants [Time frame: One year after surgery]
• Imaging results : EOS 3D, distance between anterior femoral cortex and prosthetic trochlea [Time frame: One year after surgery]
• Imaging results : radiography, evaluation of implant fixation [Time frame: One year after surgery]
• Imaging results : radiography, measurement of patellar height [Time frame: One year after surgery]
• Imaging results : radiography, evaluation of the bone structure [Time frame: One year after surgery]

Eligibility criteria

Inclusion criteria

• Patient followed as part of a consultation 1 year after TKA placement
• Adult patient
• Patient affiliated to a social security system
• Patient informed of the study and formally included (signing of informed consent) before the first research review

Exclusion criteria

• Patient with a contralateral knee prosthesis
• Patient with another condition (acquired pathology) of the lower limbs (e.g. severe osteoarthritis of the contralateral knee or hip/ankle) and/or of the nervous system (e.g. Parkinson's) which may significantly affect the quality of walking
• Pregnant patient
• Patient deprived of liberty by judicial or administrative decision,
• Adult patient subject to a legal protection measure or unable to express consent

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Non-randomized

Model

Parallel assignment

Masking

Open label

Primary purpose

Treatment

Study locations

France · 1 center

• Clinique du Sport Bordeaux Merignac — Mérignac

Identifiers

NCT: NCT06158646 · 2023-A01312-43

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗