NCT06617871 · Northwestern University
Mechanical Alignment vs Kalipered Kinematic Alignment Total Knee Arthroplasty
What this study is about
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).
View original scientific description
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.
Interventions
PROCEDURE
Mechanical Alignment (MA)
Primary TKA with the Medacta SpheriKA, utilizing either MA methodology.
PROCEDURE
Kinematic Alignment (KA) Interventions:
Primary TKA with the Medacta SpheriKA, utilizing either KA methodology.
Primary outcome measures
6-week Knee Injury and Osteoarthritis - Joint Replacement Score (KOOS-JR)
Time frame: 6 weeks postoperative
The Knee Injury and Osteoarthritis Score - Joint Replacement (KOOS-JR) score; range: 0 (worst knee health) - 100 (perfect knee health)
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Patient undergoing primary TKA with a medially-stabilized SpheriKA knee system
- Able to read and understand consent form and PRO instruments and willing to return for follow up visits
Exclusion criteria
- Varus or Valgus malalignment \>15 degrees to mechanical axis
- Flexion contracture \>15 degrees or flexion \<90 degrees
- Revision TKA or other prior knee surgery other than arthroscopy or arthroscopic-assisted ligament reconstruction
- Diagnosis or history of any of the following
- inflammatory arthritis
- infection in study knee
- chronic pain
- chronic opioid use
- metabolic musculoskeletal disorder other than osteopenia/osteoporosis
- Patients receiving workers' compensation for study condition
- Patients who cannot complete questionnaires in English
- Patients with comorbidities preventing surgery
- Patients who are not able to provide informed consent
Where
- Chicago, Illinois
Collaborators
Medacta International SA
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Mar 24, 2026 · Source of record for eligibility and locations