Comparison Between Medial Pivot Versus Symmetric Insert Total Knee Arthroplasty

Comparison Between Medial Pivot Versus Symmetric Insert Total Knee Arthroplasty: A Randomized Controlled Study

The functional outcome and longevity of total knee arthroplasty (TKA) is still a concern. Despite various developments in TKA designs, including fixed or mobile bearing, cruciate retaining or posterior stabilized, multi or single radius, it remains unclear which design is superior for achieving a physiological kinematic.

In normal healthy knees the medial and lateral tibial condyles are different: the medial is almost flat while the lateral is somewhat convex. Thus, the movement during flexion is asymmetric: during the flexion, the medial condyle is stable throughout the range of motion while the lateral condyle slides anteroposteriorly with respect to femur). Therefore, the native knee requires a specific degree of rollback of the lateral compartment coupled with a medial pivot, which leads to an external axial rotation of the femur. This rollback is thought to be even more pronounced with increasing knee flexion angles to enable deep flexion without excessive shear forces acting at the patella or overloading the extensor mechanism.

In addition, stability throughout flexion is a crucial element to normal knee function. Most TKA designs removal of the ACL, and the PCL in posterior-stabilized design, but the TKA do not fully restore the function of those ligaments.

Based on this philosophy, the medial pivot TKA was designed to provide better function, patient satisfaction and increased survival.

The objective of this study is to analyze whether the medial pivot design provides better outcome and prosthesis survival than conventional total knee arthroplasty.

Study Overview

• Status: Recruiting
• Conditions: Knee Osteoarthritis
• Intervention / Treatment: Device: total knee arthroplasty with medial pivot tibial insert or symmetrical insert

Detailed Description

Candidates for the study will be consecutive patients eligible for total knee arthroplasty (TKA) at our center. All patients meeting inclusion criteria will be recruited for enrollment into the study. Informed consent will be obtained from the patient prior to randomization.

At that time, each patient will be randomized into one of two groups by an independent staff using computer generated randomization and allocation concealment. The two patient groups will include:

1. Study group: patients treated with a medial pivot TKA.
2. Control group: patients treated with a conventional TKA. Patients will be preoperatively assessed and postoperatively at regular intervals (6mo, 12 mo, and then annually) by orthopaedic surgeons not involved in the surgeries or cares.

• Study Type: Interventional
• Enrollment (Anticipated): 100
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Alejandro Lizaur-Utrilla, MD, PhD; Phone Number: +34 966989019; Email: lizaur1@telefonica.net

Study Locations

• Spain
  • Alicante
    • Elda, Alicante, Spain, 03600
      • Recruiting
      • Elda University Hospital
      • Contact: Alejandro Lizaur-Utrilla, PhD, MD; Email: lizaur1@telefonica.net
      • Principal Investigator: Alejandro Lizaur-Utrilla, PhD, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 50 years to 99 years (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Primary osteoarthritis of the knee
• 50 years and older
• Participants must be able to give informed consent

Exclusion Criteria:

• Inflammatory arthritis
• Traumatic etiology
• Neurologic disease
• Neoplastic disease
• Morbid obesity
• Severe collateral ligament instability (> 10° varus/valgus)
• Severe knee misalignment (greater than 10° of varus or valgus)
• Flexion contracture greater than 15º
• Prior surgery on the affected knee (except meniscus)
• Knee arthroplasty in the contralateral knee

Study Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: DOUBLE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
ACTIVE_COMPARATOR: Medial pivot group; Device used: medial pivot total knee arthroplasty design	Device: total knee arthroplasty with medial pivot tibial insert or symmetrical insert; standard surgical implantation of total knee arthroplasty
ACTIVE_COMPARATOR: Conventional group; Device used: conventional total knee arthroplasty design	Device: total knee arthroplasty with medial pivot tibial insert or symmetrical insert; standard surgical implantation of total knee arthroplasty

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The Knee Society Score	Functional KSS score (range 0-100) with higher scores as better outcome. A good result is defined as 70 points or greater	2 years

Collaborators and Investigators

• Sponsor: Elda University Hospital
• Collaborators: Universidad Miguel Hernandez de Elche
• Investigators: Principal Investigator: Alejandro Lizaur-Utrilla, MD, PhD, Elda University Hospital

Study record dates

Study Major Dates

• Study Start (ACTUAL): January 1, 2022
• Primary Completion (ANTICIPATED): December 31, 2024
• Study Completion (ANTICIPATED): December 31, 2025

Study Registration Dates

• First Submitted: February 21, 2021
• First Submitted That Met QC Criteria: February 23, 2021
• First Posted (ACTUAL): February 24, 2021

Study Record Updates

• Last Update Posted (ACTUAL): April 7, 2022
• Last Update Submitted That Met QC Criteria: April 6, 2022
• Last Verified: April 1, 2022

More Information

Terms related to this study

• Keywords: knee osteoarthritis; Total knee arthroplasty; Medial pivot
• Additional Relevant MeSH Terms: Joint Diseases; Musculoskeletal Diseases; Rheumatic Diseases; Arthritis; Osteoarthritis; Osteoarthritis, Knee
• Other Study ID Numbers: MedialPivotPTR2021

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: IPD that underlie results in a publication
• IPD Sharing Time Frame: 6 months after publication
• IPD Sharing Access Criteria: Request to the principal investigator
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No