Stability of Contemporary Knee Arthroplasty

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

Evaluation of Early Migration of Medially Stabilized Arthroplasty as a Predictor of Long Time Survivorship (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 implants designs have been developed to solve the problem. However, most of their designs are based on experimental data and little has been studied about their actual performance in vivo. In this study, the investigators will analyze the in vivo stability of the Global Medacta Knee Sphere (GMK Sphere) implant. Migration of the implants will be monitored with a high precision measuring method called Radiostereometric Analysis (RSA). The investigators assume the investigators study will contribute 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 knee implants is 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. Kinematics of replaced knees is 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 hip joints which are simple ball-and socket joints, the kinematics of knee joints is more complex. The kinematics are a combination of a rolling and gliding motion of the femoral condyles and rotation of the tibia. 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. All of these implants have satisfying survivorship, but unicondylar arthroplasty which retains both cruciate ligaments has the best clinical results with survivorship at 15 years 93%. In total knee replacement (TKR) the Anterior Cruciate Ligament (ACL) and possibly the Posterior Cruciate Ligament (PCL) are sacrified. When sacrificing the one or both of the cruciate ligaments, natural knee kinematics are affected. The function of the cruciate ligaments can be mimicked by different designs of the tibial insert.

The most used knee implant in Norway, the NexGen Cruciate-retaining (CR) implant design, does not retain the ACL and does not mimic natural knee kinematics. The tibial insert of the medial pivot implant design (GMK Sphere) has a constrained medial ball in socket joint and at the same time allows lateral anterioposterior movement. This new design was developed by a group of dedicated researchers. The design intention is to resemble the function of the cruciate ligaments and at the same time allow for lateral anterioposterior movement (rollback).

Small alterations in implant design can influence the survival of implants. The final design of the GMK Sphere was introduced in 2012. New implants should be monitored and assessed in small, controlled trials with high precision measuring methods.

Analytical Method

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. Clinically relevant association between early migration of tibial implants detected by RSA and late revision for loosening has been reported. Also, attempts to measure in vivo polyethylene wear have been reported using RSA.

Purpose of this study

The aim of this study is to analyse the in vivo performance (e.g. stability) of a medially stabilized knee arthroplasty implant (Medacta International, GMK Sphere) using static RSA method over a period of 5 years. 2-year results have already been analysed and are inconclusive in regards to migration as the implant is apparently stable, but shows greater than anticipated movement. Mid-term follow-up (5-year) is therefore essential to evaluate migration of this implant. We therefore wish to obtain 5-year follow-ups of these patients.

Additionally, the investigators will analyse the wear in the ball and socket (medial) side of the tibiofemoral articulation.

30 patients will go through stability and wear testing with static RSA.

This study will contribute to the safety for patients with this new implant by providing basic knowledge of this knee arthroplasty and promoting further development of knee implant designs.

Study Type

Interventional

Enrollment (Estimated)

31

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

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

50 years to 75 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Patients with knee osteoarthritis

Exclusion Criteria:

  • Preoperative severe deformity (Femoro-tibial angle < 175°or > 190°measured on a full-length leg image at weight bearing)
  • Preoperative flexion contracture more than 15°
  • Preoperative limited range of motion under anesthetics (less than 110°)
  • Less than 50 or more than 75 years of age at the time of surgery
  • Use of walking aids because of other musculoskeletal and neuromuscular problems
  • Preoperative diagnosis other than osteoarthritis and avascular necrosis (e.g. rheumatoid arthritis, tumors)
  • Revision arthroplasty
  • Obesity with BMI >35
  • Impaired collateral ligaments
  • Malposition of femoral and tibial implants (Internally rotated or more than 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)
  • 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: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: GMK Sphere
Patients receive a GMK Sphere Total Knee Replacement.
Procedure: Medacta International, GMK Sphere medially stabilized knee
Total Knee Replacement

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Stability of the GMK Sphere prosthesis measured by Radiostereometric Analysis (RSA)
Time Frame: 5 years
Stability of the implant is measured in mm after 5 years (Maximum Total Point Motion in mm, MTPM)
5 years

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Knee Society Score (KSS)
Time Frame: 5 years
Patient reported outcome measures
5 years
Forgotten Joint Score 12 (FJS-12)
Time Frame: 5 years
Patient reported outcome measures
5 years
Knee injury and Osteoarthritis Outcome Score (KOOS)
Time Frame: 5 years
Patient reported outcome measures
5 years
Range of motion (ROM)
Time Frame: 5 years
Clinical measurement using goniometer
5 years
Hip-knee-ankle angle (HKA-angle)
Time Frame: 5 years
The axis of the lower extremity after knee arthroplasty
5 years
CT-rotation of implants
Time Frame: 5 years
Evaluation of tibia implant rotation using Berger's method
5 years
Stability of the GMK Sphere prosthesis
Time Frame: 5 years
Stability of the implant is measured in mm and degrees after 5 years using RSA (translation and rotasjon for x, y and z)
5 years

Collaborators and Investigators

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

Sponsor

Oslo University Hospital

Collaborators

Medacta International SA
Helse More and Romsdal Trust

Investigators

  • Study Director: Stephan Maximillian Røhrl, MD, PhD, Center for Implant and Radiostereometric Research Oslo (CIRRO)
  • Principal Investigator: Frank-David Oehrn, MD, Kristiansund Hospital, Helse More and Romsdal Trust
  • Principal Investigator: Lars Harald William Engseth, MD, PhD, Center for Implant and Radiostereometric Research Oslo (CIRRO)

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 (Actual)

May 1, 2016

Primary Completion (Estimated)

December 31, 2024

Study Completion (Estimated)

December 31, 2024

Study Registration Dates

First Submitted

April 28, 2016

First Submitted That Met QC Criteria

August 9, 2016

First Posted (Estimated)

August 10, 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

  • 424444-1

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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