Coated vs. Standard Knee Implants for Osteoarthritis

Overseen By Janel Dhooma, MPH

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's

Disqualifiers: Infection, Inflammatory arthropathy, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 11

50 Participants Needed

Trial Summary

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications.

What data supports the effectiveness of the Evolution Knee System, Evolution® NitrX™ Knee System treatment for osteoarthritis?

Research on similar knee implant systems suggests that newer designs can improve patient satisfaction and functional outcomes. For example, studies have shown that high-flexion and kinematic designs in knee implants can enhance range of motion and reduce bone resorption, which may indicate potential benefits for the Evolution Knee System. ^{1 2 3 4 5}

Is the Evolution® NitrX™ Knee System safe for humans?

A study comparing standard and coated knee implants found that both had similar safety outcomes, with a 98% survival rate for coated implants and 97% for uncoated ones after 5 years. Most blood markers for inflammation were similar, although some were slightly higher in the uncoated group, suggesting the coated implants are generally safe. ^{1 5 6 7 8}

What makes the Evolution® NitrX™ Knee System treatment unique for osteoarthritis?

The Evolution® NitrX™ Knee System is unique because it uses a special coating that may enhance bone ingrowth, potentially leading to better stability and longevity of the knee implant compared to standard options. This coating approach is similar to other successful knee systems that use coatings like hydroxyapatite to improve fixation without the need for cement. ^{9 10 11 12 13}

What is the purpose of this trial?

Metal hypersensitivity is a recognized complication in some patients following total joint arthroplasty. This can result in a reaction to metal particles from the implants placed in the joint and cause tissue injury. The Evolution® NitrX™ (MicroPort Orthopaedics, Memphis, TN) knee implant was designed with the addition of a coating meant to create a barrier against the release of metal ions. The primary purpose of this study is to compare the Evolution and Evolution NitrX implant (implants your surgeon uses in total knee arthroplasty surgery). This study will compare the stability of these knee implants (any movement the implant makes after surgery) through the use of specialized xrays, called "radiostereometric analysis" (RSA for short). The investigators will also compare levels of circulating metal particles with blood draws and the effects of any circulating metal with MR imaging. The investigators will also be looking at the participants clinical outcomes using joint function and patient satisfaction questionnaires. A total of 50 patients will be enrolled into the study.

Research Team

Edward M Vasarhelyi, MD

Principal Investigator

London Health Sciences Centre

Matthew Teeter, PhD

Principal Investigator

London Health Science Centre

Eligibility Criteria

This trial is for adults aged 21-80 with knee osteoarthritis, specifically those who have a varus knee deformity of 0 to 10 degrees and intact ligaments suitable for keeping the posterior cruciate ligament during surgery. Participants must be able to follow up, complete self-evaluations, consent to the study, and have no issues with undergoing MRI scans.

Inclusion Criteria

My knee bends slightly inward.

Patients willing and able to comply with follow-up requirements and self-evaluations

No contraindications to Magnetic Resonance Imaging (MRI)

Exclusion Criteria

I have had an infection before or have one now.

I need surgery involving bone implants or special supports.

I have PCL deficiency.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Pre-operative Assessment

Participants undergo pre-operative assessments including blood draws and questionnaires to evaluate baseline health status and metal exposure/sensitivity

1-2 weeks

1 visit (in-person)

Surgery and Initial Recovery

Participants undergo total knee arthroplasty surgery with either the Evolution or Evolution NitrX Total Knee System

2 weeks

1 visit (in-person)

Post-operative Monitoring

Participants are monitored for implant stability and metal levels through radiostereometric analysis, blood draws, and MR imaging

2 years

Multiple visits (in-person) at 6 weeks, 3 months, 6 months, 1 year, and 2 years

Follow-up

Participants are monitored for safety and effectiveness after treatment, including joint function and patient satisfaction assessments

2 years

Multiple visits (in-person) at 3 months, 1 year, and 2 years

Treatment Details

Interventions

• Evolution Knee System
• Evolution® NitrX™ Knee System

Trial Overview The study compares two types of knee implants used in total knee arthroplasty: Evolution NitrX Knee System (with a special coating) versus the standard Evolution Knee System. It aims to assess implant stability using radiostereometric analysis (RSA), measure metal particles in blood, examine effects via MRI, and evaluate joint function and patient satisfaction through questionnaires.

Participant Groups

Group I: Evolution with NitrX Total Knee Arthroplasty system Experimental Treatment 1 Intervention

Patients will undergo total knee arthroplasty with the NitrX Evolution Total Knee System which has the specialized protective coating

Group II: Evolution Total Knee Arthroplasty system Active Control 1 Intervention

Patients will undergo total knee arthroplasty with the Evolution Total Knee System

Who Is Running the Clinical Trial?

London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's

Lead Sponsor

Trials

678

Recruited

421,000+

London Health Sciences Centre Research Institute and Lawson Research Institute of St. Joseph's

Lead Sponsor

Trials

686

Recruited

427,000+

Lawson Health Research Institute

Lead Sponsor

Trials

684

Recruited

432,000+

MicroPort Orthopedics Inc.

Industry Sponsor

Trials

33

Recruited

3,700+

Findings from Research

In a study of 88 total knee arthroplasties (TKAs) comparing a new kinematic knee prosthesis to a traditional design, both groups showed similar clinical outcomes after 5 years, with no significant differences in knee society scores or range of motion.

However, the new prosthesis group reported lower incidences of anterior knee pain (8.5% vs 21.9%) and crepitation (14.6% vs 32.9%), suggesting improved patient satisfaction with the newer design.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Medial tibial bone resorption following total knee arthroplasty comparing a traditional with a kinematic design. Saini, MK., Reddy, CD., Reddy, NR., et al.[2023]

The study involving 80 participants found no significant difference in patient-reported outcomes (Oxford Knee Score) between the newer Journey II BCS and the older Genesis II total knee replacement designs at 6 months post-surgery.

However, the Genesis II group showed superior biomechanical outcomes, including greater walking range of motion and higher peak knee flexion velocity, suggesting it may offer better functional performance compared to the Journey II BCS.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparison of the Journey II bicruciate stabilised (JII-BCS) and GENESIS II total knee arthroplasty for functional ability and motor impairment: the CAPAbility, blinded, randomised controlled trial. McNamara, I., Pomeroy, V., Clark, AB., et al.[2023]

References

1. Netherlands pubmed.ncbi.nlm.nih.gov

High-flexion implants in primary total knee arthroplasty: a meta-analysis. [2008]

2. Germany pubmed.ncbi.nlm.nih.gov

Total knee arthroplasty at 15-17 years: does implant design affect outcome? [2022]

3. Germany pubmed.ncbi.nlm.nih.gov

The influence of alignment in long-term functional outcome of total knee arthroplasty. [2022]

4. Germany pubmed.ncbi.nlm.nih.gov

Medial tibial bone resorption following total knee arthroplasty comparing a traditional with a kinematic design. [2023]

5. England pubmed.ncbi.nlm.nih.gov

Comparison of the Journey II bicruciate stabilised (JII-BCS) and GENESIS II total knee arthroplasty for functional ability and motor impairment: the CAPAbility, blinded, randomised controlled trial. [2023]

6. Sweden pubmed.ncbi.nlm.nih.gov

Blood cytokine pattern and clinical outcome in knee arthroplasty patients: comparative analysis 5 years after standard versus "hypoallergenic" surface coated prosthesis implantation. [2020]

7. England pubmed.ncbi.nlm.nih.gov

Camouflage uncovered: what should happen next? [2023]

8. United Arab Emirates pubmed.ncbi.nlm.nih.gov

Comparative Study of Clinical and Radiological Outcomes of Unconstrained Bicondylar Total Knee Endoprostheses with Anti-allergic Coating. [2021]

9. United States pubmed.ncbi.nlm.nih.gov

The Natural-Knee system: 25 years of successful results. [2016]

10. United States pubmed.ncbi.nlm.nih.gov

Retrospective evaluation of the Duracon periapatite-coated tibial tray: midterm results and factors affecting success. [2013]

11. United States pubmed.ncbi.nlm.nih.gov

Uncemented tibial fixation total knee arthroplasty. [2022]

12. United States pubmed.ncbi.nlm.nih.gov

Fixation of the NexGen HA-TCP-coated cementless, screwless total knee arthroplasty: comparison with conventional cementless total knee arthroplasty of the same type. [2019]

13. United States pubmed.ncbi.nlm.nih.gov

Unicompartmental porous coated anatomic total knee arthroplasty. [2016]