Kinematics of Contemporary Knee Arthroplasty

February 3, 2024 updated by: Stephan M Rohrl, Oslo University Hospital

Comparison of in Vivo Kinematics of Different Implants in ACL-sacrificing vs. Medially Stabilized Arthroplasty (Implant Design Study)

Total joint replacement is an efficacious treatment for osteoarthritis of hips and knees. Both total knee replacement (TKR) and total hip replacements (THR) have excellent implant survivorship. However, patient satisfaction is lower in TKR than THR. A possible cause of the discrepancy is the unnatural knee kinematics after TKR. Various implant designs have been developed to solve the problem. However, most of the designs are based on experimental data and not on in vivo kinematics. In this study, we will analyze the in vivo kinematics of the Global Medacta Knee Sphere (GMK Sphere) implant and compare it with a well documented design and implant (NexGen Cruciate Retaining (CR), Zimmer Biomet). We assume our study will contribute to the development of more satisfying knee implants.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Detailed Description

Worldwide the number of patients requiring treatment for osteoarthritis is increasing due to increasing obesity, an ageing population and a high demanding younger population. Learmonth describes hip arthroplasty as the "operation of the century" because patients are highly satisfied with pain relief and function after the procedure. Knee arthroplasties have in recent years also shown promising results and have surpassed hip arthroplasty in frequency in western countries. However, patient satisfaction is not as high. Reported problems are insufficient function and persistent pain. On the other hand, knee arthroplasties are increasingly implanted in younger and more active patients who require high function and quality of life. Improvement of results after knee arthroplasty is therefore an urgent issue in the field of orthopaedic research.

Knee kinematics and implant designs:

A possible cause of lower function of replaced knees is the unnatural postoperative knee kinematics. The kinematics of replaced knees are closely related to their function. Studies show that replaced knees with excellent flexion angles have kinematic similarities to normal knees and malalignments of implants can cause postoperative pain.

Compared to the hip joint which is a simple ball-and-socket joint, the kinematics of knee is more complex. Native knee kinematics are a combination of a rolling and gliding motion of the femoral condyles and rotation of the tibia, where roll back of the lateral femoral condyle is larger than medially. Roll back is important for high degrees of flexion. Native knee kinematics are not fully understood, but the anterior cruciate ligament (ACL) seems to be an integral part, as knees without a functioning ACL show decreased roll back. Based on the kinematics of the normal knee joint, various attempts have been made on the design of knee implants to reconstruct normal kinematics after replacement surgery, but in knee osteoarthritis the ACL and posterior cruciate ligament (PCL) is often deficient as they are damaged by inflammation. Therefore, there are three concepts regarding the retaining of these ligaments in knee replacement surgery. 1: Sacrifice both the ACL and PCL, 2: Retain the PCL (cruciate retaining (CR) design), 3: Retain both the ACL and PCL (bicruciate-reataining design).

The function of the cruciate ligaments can be mimicked by different designs of the tibial insert. The CR design has been widely used in the northern countries, especially the Zimmer Biometri NexGen CR implant in Norway. There are migration data for the NexGen implant with high precision measurements available in the literature. However, the NexGen CR implant does not retain the ACL and does not mimic natural knee kinematics.

The tibial insert of the medially stabilized implant design (Medacta International, GMK Sphere) has a constrained medial "ball in socket" joint and at the same time allows lateral anterioposterior movement (roll back). This new design was developed by a group of dedicated researchers. The design intention is to resemble the native kinematics of the knee by mimicing the function of the cruciate ligaments and at the same time allow for lateral anterioposterior movement (rollback). Theoretically, knee implant designs, which retain the function of cruciate ligaments are predicted to have the closest kinematics to normal knees compared to other designs and to have the potential to achieve the highest patient satisfaction.

Analytical Method:

Radiostereometric Analysis (RSA) has been used in orthopedic research fields since 1970s. The original application of this method was for the evaluation of implant migration (i.e. fixation) and polyethylene wear of artificial joints using static X-ray pictures. When combining RSA with fluoroscopy, we get Fluoroscopic Roentgen Stereophotogrammetric Analysis (FRSA), a method with high accuracy and precision. Few implants have been analysed kinematically in vivo. We plan to investigate the knees during in vivo motion and weight-bearing using FRSA.

Purpose of the study:

The aim of this study is to analyse the in vivo kinematics of a medially stabilized knee arthroplasty implant (GMK Sphere) and to compare it with a well known design (Nexgen CR, Zimmer Biomet) by using FRSA.

By using flat panel fluoroscopy, we will document and compare the kinematics of the two implants in all 6 degrees of freedom (DOF).

26 patients will be randomized into two groups, one will receive the NexGen CR prosthesis, the other group the GMK Sphere.

Study Type

Interventional

Enrollment (Actual)

26

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Norway
      • Oslo, Norway, 0470
        • Oslo University Hospital, Ullevål

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

48 years to 73 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

1. Patients with knee osteoarthritis

Exclusion Criteria:

  1. Preoperative severe deformity (Femoro-tibial angle < 175°or > 190° measured on a full-length leg image at weight bearing)
  2. Preoperative flexion contracture more than 15°
  3. Preoperative limited range of motion under anesthetics (less than 110°)
  4. Less than 50 or more than 75 years of age at the time of surgery
  5. Use of walking aids because of other musculoskeletal and neuromuscular problems
  6. Preoperative diagnosis other than osteoarthritis and avascular necrosis (e.g. rheumatoid arthritis, tumors)
  7. Revision arthroplasty
  8. Obesity with BMI>35
  9. Impaired collateral ligaments
  10. Postoperative KOOS score less than 80
  11. Malposition of femoral and tibial implants (Internally rotated or more han 10° externally rotated implants will be excluded. The rotation of femoral implant is measured on postoperative CT images in reference to surgical epicondylar line. The rotation of tibial implant is determined according to Berger's measurement)
  12. Limb surgery within 3 months before the analysis
  13. Postoperative revision surgery due to deep wound infection

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Zimmer Biomet NexGen CR
Patients receive a Zimmer Biomet NexGen Total Knee Replacement
Procedure: Zimmer Biomet NexGen CR
Total Knee Replacement
Active Comparator: Medacta International GMK Sphere
Patients receive a Medacta International, GMK Sphere Total Knee Replacement
Procedure: Medacta International GMK Sphere
Total Knee Replacement

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Knee Kinematics measured though all Degrees of freedom (DOF)
Time Frame: 1 year
Roentgen Fluoroscopic Stereophotogrammetric Analysis (RFSA). We measure all DOFs (i.e. X-Y-Z rotations and translations in degrees and millimeters respectively)
1 year

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Knee Society Score (KSS)
Time Frame: 1 year
Patient Reported Outcome Measure (PROM)
1 year
Knee injury and Osteoarthritis Outcome Score (KOOS)
Time Frame: 1 year
PROM
1 year
Forgotten Joint Score 12 (FJS-12)
Time Frame: 1 year
PROM
1 year
Range of motion (ROM)
Time Frame: 1 year
Clinical measurement using goniometer
1 year
Hip-knee-ankle angle (HKA-angle)
Time Frame: 1 year
The axis of the lower extremity after knee arthroplasty
1 year
CT-rotation of implants
Time Frame: 1 year
Evaluation of tibia implant rotation using Berger's method
1 year
Clinical stability
Time Frame: 1 year
Varus-valgus stability in clinical testing
1 year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Oslo University Hospital

Collaborators

Helse More and Romsdal Trust

Investigators

  • Principal Investigator: Frank-David Oehrn, MD, CIRRO and Kristiansund Hospital, Helse More and Romsdal Trust
  • Study Director: Stephan Maximillian Røhrl, PhD, CIRRO and Oslo University Hospital, Ullevål
  • Principal Investigator: Lars Harald William Engseth, MD, CIRRO and Oslo University Hospital, Ullevål

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

November 1, 2016

Primary Completion (Estimated)

December 1, 2025

Study Completion (Estimated)

December 1, 2025

Study Registration Dates

First Submitted

November 14, 2016

First Submitted That Met QC Criteria

November 16, 2016

First Posted (Estimated)

November 17, 2016

Study Record Updates

Last Update Posted (Estimated)

February 6, 2024

Last Update Submitted That Met QC Criteria

February 3, 2024

Last Verified

February 1, 2024

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 424444-2

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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