Prospective Randomized Study Comparing the SpheriKA® (MEDACTA) and Origin® (SYMBIOS) Prostheses During Total Knee Replacement Using the Kinematic Alignment Technique

Overview

The traditional technique for implanting a total knee prosthesis, known as mechanical alignment, does not aim to preserve the original anatomy and laxity of the knee. Instead, the implants are "systematically" aligned to create a non-naturally straight lower limb. Respectively 20% and 50% of patients with a mechanically aligned total knee prosthesis are dissatisfied with the result, and complain of residual symptoms. A newer, more physiological technique for implanting a total knee prosthesis, known as kinematic alignment, aims to recreate the unique native anatomy and laxity of each patient\'s knee. The kinematic alignment technique has been shown to reduce the risk of residual symptoms and thus improve the patient\'s experience of his or her prosthetic knee. As a result of the emergence of the kinematic alignment technique, two manufacturers have developed total knee prosthesis implants specifically for this new insertion technique. A "made-to-measure" total knee prosthesis (ORIGIN® - Symbios, Yverdon-les-Bains, Switzerland) was developed with the aim of reproducing the unique contour of each implanted knee. Another manufacturer opted to develop a generic total knee prosthesis implant (SPHERIKA® - Medacta, Castel San Pietro, Switzerland), but with a design optimized for the kinematic alignment technique. These two models of total knee prosthesis each offer advantages and limitations that need to be assessed. The main aim of this study is therefore to compare the joint perception of these 2 prostheses. It will also look at the clinical and imaging results, the biomechanics of the prosthetic knee during gait, and the muscular strength of knee extension, obtained for these 2 total knee prostheses.

Interventions

• Procedure SPHERIKA prosthesis
  total knee arthroplasty with kinematic alignement with SPHERIKA prosthesis
• Procedure ORIGIN prosthesis
  total knee arthroplasty with kinematic alignement with ORIGIN prosthesis

Primary outcome measures

• Evolution of "forgotten joint score" [Time frame: 2 months before surgery ; 45 days after surgery ; 1 year after surgery ; 2 years after surgery]

Secondary outcome measures (3)

• Frontal alignment of the lower limb [Time frame: 2 months before surgery ; 45 days after surgery ; 1 year after surgery ; 2 years after surgery]
• Walking ability [Time frame: 2 years after surgery]
• Evaluation of muscular strength [Time frame: 2 years after surgery]

Eligibility criteria

Inclusion criteria

• Patient with indication for initial total knee replacement
• Patient affiliated to a social security scheme
• Patient informed of the study and formally included (informed consent signed) before the first research examination.

Exclusion criteria

• Patient with complex osteoarthritis (e.g. bone loss, history of patellar instability)
• Patient with contralateral knee prosthesis
• Patient with symptomatic osteoarthritis (stiffness and/or pain) of a hip or contralateral knee
• Patient with another condition (acquired pathology) of the lower limbs and/or nervous system that may significantly affect gait quality
• Patient deprived of liberty by judicial or administrative decision,
• Patient of legal age under legal protection 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

Randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Treatment

Study locations

France · 1 center

• Clinique du Sport — Mérignac

Identifiers

NCT: NCT06603103 · 2023-21-SBM

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗