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Two ways of placing a new knee joint in knee osteoarthritis surgery

Compares two knee replacement alignment methods in people with knee osteoarthritis.

Key facts

Who runs it
Northwestern University
Where
Chicago, United StatesSee the site
Trial code
Registry title
Mechanical Alignment vs Kalipered Kinematic Alignment Total Knee Arthroplasty
Status
Recruiting
People taking part
95 people, planned
Started
1 Aug 2024
Expected to end
Dec 2028
Type of study
Interventional, 2 groupsOne group gets an existing treatment, for comparison.
Treatments tested
  • Mechanical Alignment (MA)
  • Kinematic Alignment (KA) Interventions:
Record updated
24 March 2026

Who can take part

AI summary

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for adults having a first total knee replacement with the SpheriKA knee system. It compares two ways of positioning the new knee.

Age
21 Years to 79 Years
Sex
All sexes can join.
Disease stage
Knee osteoarthritis or other knee joint disease needing a first (primary) total knee replacement.
Earlier treatment
No earlier knee replacement or other knee surgery, except arthroscopy (keyhole surgery) or arthroscopic-assisted ligament repair.

Main reasons for not taking part

  • Knee bent inward or outward more than 15 degrees, flexion contracture over 15 degrees, or bending under 90 degrees
  • BMI over 40
  • Inflammatory arthritis, infection in the study knee, chronic pain or long-term opioid use
  • Receiving workers' compensation for the knee condition
  • Cannot complete questionnaires in English, or other illnesses that prevent surgery

The registry criteria, word for word

Show all 11 criteriaShow less

Who can take part

  • 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

Who cannot take part

  • Revision TKA or other prior knee surgery other than arthroscopy or arthroscopic-assisted ligament reconstruction
  • Patients receiving workers' compensation for study condition
  • Patients with comorbidities preventing surgery
  • 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
  • Varus or Valgus malalignment >15 degrees to mechanical axis
  • Flexion contracture >15 degrees or flexion <90 degrees
  • BMI >40
  • Patients who cannot complete questionnaires in English
  • Patients who are not able to provide informed consent

Check if you might fit

Answer for yourself. This is not a decision: only the study team can say whether you can take part.

  • Are you between 21 and 79 years old?

Where in United States

  • Northwestern MedicineChicago, United StatesContact: Melissa Shauver, MPHTaking people

About the trial

What the trial wants to find out

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.

Read full original descriptionShow less

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.

The 2 groups in the trial

  • Mechanical Alignment (MA)Existing treatment, for comparison

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

  • Kinematic Alignment (KA)Existing treatment, for comparison

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

    Treatment: Kinematic Alignment (KA) Interventions:

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record → Contacts and Locations

Print a page for my doctor

Data and sources

Registry record
Listed on ClinicalTrials.gov.
Official title
A Prospective, Randomized, Single-blinded Clinical Trial Comparing Mechanical Alignment vs Kalipered Kinematic Alignment Total Knee Arthroplasty Using Medacta Spherika
Plain-language title
Two ways of placing a new knee joint in knee osteoarthritis surgeryGenerated from the registry record. The registry title is the official one.
AI summary
From the trial's eligibility criteria. Read by machine on 14 November 2026.
Fit questions
Built from NCT06617871, who can take part
Record updated
24 March 2026