Knee Replacement Techniques for Osteoarthritis

(KMART Trial)

Overseen By Kim Madden, PhD

Age: 18+

Sex: Any

Trial Phase: Phase 4

Sponsor: McMaster University

Disqualifiers: Cognitive disability, Language barrier, others

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

Prior Safety Data This treatment has passed at least one previous human trial

Compensation: Varies

Number of Visits: 5

Duration: 1 week

260 Participants Needed

Trial Summary

What is the purpose of this trial?

Knee replacement surgery is the second most common surgery in Canada. People who have very painful knee arthritis usually receive a knee replacement where the surgeon aims to make everyone's knee as straight as possible (called mechanical alignment). Mechanical alignment focuses on making the implant last as long as possible. However, everybody's knee shape is different and we think that it is important to take individual differences into account. A newer technique that is more personalized is called restricted kinematic alignment. This technique customizes the placement of the new knee to reproduce each patient's unique knee shape, which may not be perfectly straight. We think this newer technique may feel more natural, be more stable, and lead to better knee function. Restricted kinematic alignment might last as long or longer than mechanical alignment, but the research that has been conducted to date is not clear. We are conducting this study to help surgeons better understand which technique is better. One of the reasons the existing research is not clear is because new developments in robotic technology now allow surgeons to place knee implants very precisely, which was not done in most previous research. In this study everyone will receive a robot-assisted knee surgery so we can be sure the implants are placed as precisely as possible. The purpose of this trial is to determine whether there are differences in patient outcomes using restricted kinematic alignment rather than the traditionally used mechanical alignment for total knee replacements. Participants who are having total knee replacements will be randomized to receive either a robot-assisted total knee replacement using mechanical alignment, or a robot-assisted total knee replacement using restricted kinematic alignment . We will ask participants to walk in a markerless motion capture system which will measure walking characteristics at pre-op, 6 months postop and 12 months postop. Participants will also complete a series of standardized questionnaires at preop and 6 months, 12 months, and 24 month postop.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. It's best to discuss this with the trial coordinators or your doctor.

What data supports the effectiveness of the treatment Mechanically-Aligned Arthroplasty, Restricted Kinematically-aligned Arthroplasty for knee osteoarthritis?

Research shows that kinematically aligned knee replacements, which aim to mimic the knee's natural movement, often result in better pain relief and a more natural feeling knee compared to mechanically aligned replacements. This suggests that the kinematic alignment technique may be more effective in restoring normal knee function and improving patient outcomes. ^{1 2 3 4 5}

Is knee replacement surgery using kinematic or mechanical alignment safe?

The studies mainly focus on comparing outcomes like knee motion and satisfaction between kinematic and mechanical alignments, but they do not provide specific safety data. However, these techniques are commonly used in knee replacement surgeries, suggesting they are generally considered safe. ^{1 5 6 7 8}

How does the kinematic alignment technique for knee replacement differ from other treatments for osteoarthritis?

The kinematic alignment technique for knee replacement is unique because it aims to restore the natural alignment of the knee by positioning the implant to match the patient's pre-arthritic knee anatomy, unlike traditional methods that use a standard mechanical alignment. This approach can lead to better functional outcomes and a more natural feeling knee post-surgery. ^{2 3 4 9 10}

Eligibility Criteria

This trial is for individuals with painful knee arthritis who are candidates for total knee replacement surgery. Participants will be those interested in a robot-assisted procedure and willing to undergo motion capture assessments and complete questionnaires before and after the operation at specified intervals.

Inclusion Criteria

I need a knee replacement due to arthritis.

Provide informed consent

Exclusion Criteria

Inability to obtain a CT scan prior to surgery

I have had knee surgery before.

I've had recent leg surgery or injury that affects how I walk.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Preoperative Assessment

Participants undergo preoperative assessment including walking in a markerless motion capture system to measure walking characteristics

1-2 weeks

1 visit (in-person)

Treatment

Participants receive a robot-assisted total knee replacement using either mechanical alignment or restricted kinematic alignment

1 week

1 visit (in-person)

Postoperative Follow-up

Participants complete standardized questionnaires and undergo assessments at 6, 12, and 24 months post-operation to monitor outcomes such as gait biomechanics, quality of life, and knee function

24 months

3 visits (in-person)

Treatment Details

Interventions

• Mechanically-Aligned Arthroplasty
• Restricted Kinematically-aligned Arthroplasty

Trial Overview The study compares two techniques of knee replacement: traditional mechanical alignment aiming for a straight knee, versus restricted kinematic alignment tailored to individual's unique knee shape. Both methods use robotic assistance for precise implant placement, assessing which results in better patient outcomes.

Participant Groups

Group I: Restricted Kinematic Alignment Experimental Treatment 1 Intervention

Group II: Mechanical Alignment Active Control 1 Intervention

Who Is Running the Clinical Trial?

McMaster University

Lead Sponsor

Trials

936

Recruited

2,630,000+

Canadian Orthopaedic Foundation (funding)

Collaborator

Trials

2

Recruited

310+

Research Institute of St. Joseph's Hamilton

Collaborator

Trials

2

Recruited

700,000+

Findings from Research

The kinematic alignment (KA) technique in total knee replacement surgery led to significant improvements in clinical, psychological, and functional outcomes for 12 patients, as measured by various tests before and after surgery.

Patients experienced a fast postoperative recovery, with notable enhancements in their scores from the day after surgery to 14 days post-operation, indicating the potential effectiveness of KA in treating knee osteoarthritis.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Analysis of Short-Term Clinical and Functional Outcomes in Patients Undergoing Total Knee Arthroplasty with Kinematic Alignment Technique. Giorgino, R., Nannini, A., Scuttari, E., et al.[2023]

Kinematic alignment (KA) in knee replacement surgery resulted in more internal rotation of the tibia and a larger medial rotation point compared to mechanical alignment (MA), suggesting improved knee joint mechanics.

The study, which tested eight fresh frozen human knee specimens during active flexion, indicates that KA combined with a medial stabilized implant may better replicate natural knee movement during bending.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Influence of kinematic alignment on femorotibial kinematics in medial stabilized TKA design compared to mechanical alignment. Bauer, L., Woiczinski, M., Thorwächter, C., et al.[2023]

In a study of 126 patients undergoing total knee arthroplasty, those who received kinematic alignment (KA-TKA) showed significantly better clinical outcomes, including higher knee joint clinical scores and functional scores, compared to those who received mechanical alignment (MA-TKA) at both 3 months and 2 years post-surgery.

Both KA-TKA and MA-TKA resulted in similar lower limb alignment after surgery, indicating that while KA-TKA may enhance clinical performance and patient satisfaction, it does not compromise alignment outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

An early clinical comparative study on total knee arthroplasty with kinematic alignment using specific instruments versus mechanical alignment in varus knees. Wen, L., Wang, Z., Ma, D., et al.[2023]

Kinematic alignment in total knee arthroplasty resulted in better knee joint function scores and improved flexion angles compared to mechanical alignment, based on a meta-analysis of 19 studies involving 1845 total knee arthroplasties.

Despite the differences in functional outcomes, both kinematic and mechanical alignments showed similar overall clinical outcomes and complication rates, suggesting that kinematic alignment can be a safe and effective option for knee surgery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Kinematic and mechanical alignments in total knee arthroplasty: A meta-analysis with ≥1-year follow-up. Wang, G., Chen, L., Xu, J.[2023]

References

1. Germany pubmed.ncbi.nlm.nih.gov

Kinematic component alignment in total knee arthroplasty leads to better restoration of natural tibiofemoral kinematics compared to mechanic alignment. [2020]

2. Switzerland pubmed.ncbi.nlm.nih.gov

Analysis of Short-Term Clinical and Functional Outcomes in Patients Undergoing Total Knee Arthroplasty with Kinematic Alignment Technique. [2023]

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

Influence of kinematic alignment on femorotibial kinematics in medial stabilized TKA design compared to mechanical alignment. [2023]

4. Switzerland pubmed.ncbi.nlm.nih.gov

An early clinical comparative study on total knee arthroplasty with kinematic alignment using specific instruments versus mechanical alignment in varus knees. [2023]

5. Japan pubmed.ncbi.nlm.nih.gov

Kinematic and mechanical alignments in total knee arthroplasty: A meta-analysis with ≥1-year follow-up. [2023]

6. England pubmed.ncbi.nlm.nih.gov

The early outcome of kinematic versus mechanical alignment in total knee arthroplasty: a prospective randomised control trial. [2017]

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

Radiological and clinical comparison of kinematically versus mechanically aligned total knee arthroplasty. [2021]

8. Netherlands pubmed.ncbi.nlm.nih.gov

Kinematic alignment produces near-normal knee motion but increases contact stress after total knee arthroplasty: A case study on a single implant design. [2022]

9. India pubmed.ncbi.nlm.nih.gov

Combining kinematic alignment and medial stabilized design in total knee arthroplasty: Basic rationale and preliminary clinical evidences. [2022]

10. France pubmed.ncbi.nlm.nih.gov

The kinematic alignment technique for TKA reliably aligns the femoral component with the cylindrical axis. [2018]