Surgical Alignments for Knee Arthritis

Overseen By Megan VanDyke, BSN

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Northwestern University

Must not be taking: Opioids

Disqualifiers: Inflammatory arthritis, Chronic pain, others

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

Compensation: Varies

Number of Visits: 2

Duration: 1 week

95 Participants Needed

Trial Summary

Will I have to stop taking my current medications?

The trial protocol does not specify whether you need to stop taking your current medications. However, if you are using chronic opioids, you may not be eligible to participate.

What data supports the effectiveness of the treatment Kinematic Alignment for knee arthritis?

Research shows that kinematic alignment, which aims to match the knee's natural anatomy, may improve functional outcomes in knee replacement surgery compared to traditional mechanical alignment. However, results are mixed, and the best approach may depend on individual patient characteristics. ^{1 2 3 4 5}

Is kinematic alignment safe for knee surgery?

Research comparing kinematic alignment to mechanical alignment in knee surgery shows that both methods are generally safe for patients. Studies have focused on outcomes like implant survival and clinical results, indicating no major safety concerns with kinematic alignment. ^{1 3 5 6 7}

How does the kinematic alignment treatment for knee arthritis differ from other treatments?

Kinematic alignment (KA) is a unique surgical technique for knee arthritis that aims to align the knee replacement components to match the patient's natural knee anatomy, potentially improving function. This differs from mechanical alignment (MA), which positions components based on a standard neutral alignment, not tailored to individual anatomy. ^{4 8 9 10 11}

What is the purpose of this trial?

Knee replacement surgery can be performed in one of two ways. Traditionally the goal was for the new joint to be in a neutral position with respect to the femur (thigh bone). This is called Mechanical Alignment (MA). The neutral position is different than the human knee's natural position, so MA often requires the surgeon to make additional cuts to the ligaments and other soft tissue around the knee. More recently surgeons have started to place the new joint in a position that more closely replicates the natural alignment of the human knee. This is called Kinemetic Alignment (KA). KA can be done without additional soft tissue dissection but the procedure requires a higher level of precision that can be difficult to achieve in every case. Some studies have found no difference in outcomes between MA and KA, whereas others have found KA to be superior. But these were small studies or studies that did not consider patient-rated outcomes.

Research Team

Adam Edelstein, MD

Principal Investigator

Assistant Professor of Orthopaedic Surgery

Eligibility Criteria

This trial is for individuals with knee osteoarthritis needing replacement surgery. It's comparing two surgical methods: traditional Mechanical Alignment (MA) and the newer Kinematic Alignment (KA). Suitable participants should not have conditions that may interfere with the surgery or recovery.

Inclusion Criteria

I am having a knee replacement with a specific type of knee system.

Able to read and understand consent form and PRO instruments and willing to return for follow up visits

Exclusion Criteria

Patients receiving workers' compensation for study condition

I am unable to understand or sign the consent form.

My study knee has had an infection.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants undergo Total Knee Arthroplasty (TKA) using either Mechanical Alignment (MA) or Kinematic Alignment (KA) methodology

1 week

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment, including assessment of KOOS-JR score

6 weeks

1 visit (in-person)

Long-term Follow-up

Participants are assessed for long-term outcomes, including the Forgotten Joint Score (FJS)

1 year

Treatment Details

Interventions

• Kinematic Alignment
• Mechanical Alignment

Trial Overview The study tests whether aligning the new knee joint to mimic natural anatomy (KA) has better outcomes than aligning it in a neutral position (MA). The focus is on patient-rated results, addressing gaps in previous research.

Participant Groups

Group I: Mechanical Alignment (MA) Active Control 1 Intervention

Primary TKA with the Medacta SpheriKA, utilizing either MA methodology.

Group II: Kinematic Alignment (KA) Active Control 1 Intervention

Primary TKA with the Medacta SpheriKA, utilizing either KA methodology.

Kinematic Alignment is already approved in European Union, United States, Canada, Japan, China, Switzerland for the following indications:

Approved in European Union as Kinematic Alignment for:

• Total Knee Arthroplasty
• Knee Replacement Surgery

Approved in United States as Kinematic Alignment for:

• Total Knee Arthroplasty
• Knee Replacement Surgery

Approved in Canada as Kinematic Alignment for:

• Total Knee Arthroplasty
• Knee Replacement Surgery

Approved in Japan as Kinematic Alignment for:

• Total Knee Arthroplasty
• Knee Replacement Surgery

Approved in China as Kinematic Alignment for:

• Total Knee Arthroplasty
• Knee Replacement Surgery

Approved in Switzerland as Kinematic Alignment for:

• Total Knee Arthroplasty
• Knee Replacement Surgery

Who Is Running the Clinical Trial?

Northwestern University

Lead Sponsor

Trials

1,674

Recruited

989,000+

Medacta International SA

Industry Sponsor

Trials

51

Recruited

9,100+

Founded

1999

Headquarters

Castel San Pietro, Switzerland

Known For

Orthopedic innovations

Top Products

AMIS Hip Platform, MyKA Knee Platform, NextAR Spine Platform

Findings from Research

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]

This study will evaluate the effectiveness of robot-assisted surgery (RAS) and kinematic alignment (KA) in total knee arthroplasty (TKA) compared to traditional methods, involving 300 patients and assessing outcomes over 2 years using the Knee injury and Osteoarthritis Outcome Score (KOOS-12).

The research aims to determine not only the clinical and functional benefits of RAS and KA but also their impact on radiographic precision and long-term prosthetic survivorship, providing a comprehensive analysis of these modern surgical techniques.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Robotic-assisted surgery and kinematic alignment in total knee arthroplasty (RASKAL study): a protocol of a national registry-nested, multicentre, 2×2 factorial randomised trial assessing clinical, intraoperative, functional, radiographic and survivorship outcomes. MacDessi, SJ., Wernecke, GC., Bastiras, D., et al.[2022]

In a meta-analysis of 458 total knee arthroplasty patients, functional outcomes (measured by WOMAC and KSS scores) were similar between those who underwent kinematic alignment (KA) and those who had traditional mechanical alignment (MA), indicating that KA may not provide significant advantages in overall function post-surgery.

A slight improvement in pain scores was observed in the KA group, but no specific patient subgroups were identified that benefited more from the KA technique, suggesting that the choice of alignment method may not significantly impact long-term outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Outcome of kinematic alignment using patient-specific instrumentation versus mechanical alignment in TKA: a meta-analysis and subgroup analysis of randomised trials. Woon, JTK., Zeng, ISL., Calliess, T., et al.[2018]

In a study of 296 patients who underwent total knee arthroplasty, both kinematic alignment (KA) and mechanical alignment (MA) techniques showed similar clinical outcomes in terms of range of motion and knee society score after one year.

Patients with a body mass index (BMI) over 30 kg/m² had better outcomes with MA, while those with severe varus deformities (HKA angle over 10 degrees) benefited more from the KA technique, suggesting tailored approaches based on individual patient characteristics.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

How to choose kinematic or mechanical alignment individually according to preoperative characteristics of patients? Luan, C., Xu, DT., Chen, NJ., et al.[2021]

In a meta-analysis of 1112 participants, kinematic alignment (KA) in total knee arthroplasty showed significantly better functional outcomes, including improved Knee Society Scores and greater knee flexion range compared to mechanical alignment (MA).

Patients who underwent KA also had a longer walking distance before discharge, indicating enhanced recovery, while other outcomes such as complication rates remained similar between the two alignment techniques.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Kinematic alignment versus mechanical alignment in primary total knee arthroplasty: an updated meta-analysis of randomized controlled trials. Liu, B., Feng, C., Tu, C.[2022]

Kinematic alignment is emerging as a viable alternative to mechanical alignment in total knee arthroplasty (TKA), with a significant increase in research from 11 to 91 studies in the past 5 years.

This review aims to summarize the growing body of literature comparing the outcomes of kinematic alignment versus mechanical alignment, highlighting the evolving understanding of their impact on implant survival and clinical results.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Current evidence base for kinematic alignment. Tuecking, LR., Savov, P., Windhagen, H., et al.[2021]

A study analyzing 4884 knee CT scans found that using a restricted kinematic alignment (KA) protocol for total knee arthroplasty (TKA) resulted in significantly less modification of knee anatomy compared to the standard mechanical alignment (MA) technique, with mean corrections of only 0.5° for the medial proximal tibial angle (MPTA) and 0.3° for the lateral distal femoral angle (LDFA).

The restricted KA protocol allowed 51% of knees to undergo surgery without any adjustments, and 83% required only minor corrections, suggesting that this approach can better preserve the patient's native knee anatomy while still achieving effective surgical outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The Impact of Mechanical and Restricted Kinematic Alignment on Knee Anatomy in Total Knee Arthroplasty. Almaawi, AM., Hutt, JRB., Masse, V., et al.[2018]

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]

In a study of 99 total knee arthroplasties, there was no significant difference in 2-year patient-reported outcome scores between kinematic alignment (KA) and mechanical alignment (MA) techniques, suggesting that KA may not provide the expected benefits in pain and function.

While the KA technique resulted in different component alignments (more varus tibial and valgus femoral positioning), these changes did not translate into improved clinical outcomes, raising concerns about the long-term implications of these alignment differences.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The Chitranjan S. Ranawat Award : No Difference in 2-year Functional Outcomes Using Kinematic versus Mechanical Alignment in TKA: A Randomized Controlled Clinical Trial. Young, SW., Walker, ML., Bayan, A., et al.[2022]

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 (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]

References

1. Japan pubmed.ncbi.nlm.nih.gov

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

2. England pubmed.ncbi.nlm.nih.gov

Robotic-assisted surgery and kinematic alignment in total knee arthroplasty (RASKAL study): a protocol of a national registry-nested, multicentre, 2×2 factorial randomised trial assessing clinical, intraoperative, functional, radiographic and survivorship outcomes. [2022]

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

Outcome of kinematic alignment using patient-specific instrumentation versus mechanical alignment in TKA: a meta-analysis and subgroup analysis of randomised trials. [2018]

4. England pubmed.ncbi.nlm.nih.gov

How to choose kinematic or mechanical alignment individually according to preoperative characteristics of patients? [2021]

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

Kinematic alignment versus mechanical alignment in primary total knee arthroplasty: an updated meta-analysis of randomized controlled trials. [2022]

6. Germany pubmed.ncbi.nlm.nih.gov

Current evidence base for kinematic alignment. [2021]

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

The Impact of Mechanical and Restricted Kinematic Alignment on Knee Anatomy in Total Knee Arthroplasty. [2018]

8. 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]

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

The Chitranjan S. Ranawat Award : No Difference in 2-year Functional Outcomes Using Kinematic versus Mechanical Alignment in TKA: A Randomized Controlled Clinical Trial. [2022]

10. 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]

11. Germany pubmed.ncbi.nlm.nih.gov

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