Total Knee Replacement Component Alignment Using Manual Versus Custom Instrumentation

Study Purpose

1. To determine whether the low-dose, biplanar x-ray imaging (EOS) has the same accuracy as computed axial tomography (CT) 2. To validate low-dose, biplanar x-ray imaging (EOS) as a tool to evaluate 3-dimensional alignment of Total Knee Replacement implants. 3. To evaluate differences in total knee replacement implant alignment in patients whose arthroplasty is performed using manual or custom instrumentation derived from preoperative CT

Recruitment Criteria

Accepts Healthy Volunteers

Healthy volunteers are participants who do not have a disease or condition, or related conditions or symptoms

Study Type

An interventional clinical study is where participants are assigned to receive one or more interventions (or no intervention) so that researchers can evaluate the effects of the interventions on biomedical or health-related outcomes.

An observational clinical study is where participants identified as belonging to study groups are assessed for biomedical or health outcomes.

Searching Both is inclusive of interventional and observational studies.

Eligible Ages 18 Years - 90 Years
Gender All
More Inclusion & Exclusion Criteria

Inclusion Criteria:

- Radiographically confirmed diagnosis of osteoarthritis (OA) - Failure of non-operative treatment for the diagnosis of symptomatic osteoarthritis - Age greater than 18 years - Desire to proceed with elective TKR - Completion of informed consent and signature of written consent form

Exclusion Criteria:

- Ligamentous instability that may necessitate a constrained TKR implant - Retained hardware in the distal femur or proximal tibia of the operative extremity - Medical contraindication to undergo preoperative CT, or inability to tolerate preoperative CT

Trial Details

Trial ID:

This trial id was obtained from, a service of the U.S. National Institutes of Health, providing information on publicly and privately supported clinical studies of human participants with locations in all 50 States and in 196 countries.


Phase 1: Studies that emphasize safety and how the drug is metabolized and excreted in humans.

Phase 2: Studies that gather preliminary data on effectiveness (whether the drug works in people who have a certain disease or condition) and additional safety data.

Phase 3: Studies that gather more information about safety and effectiveness by studying different populations and different dosages and by using the drug in combination with other drugs.

Phase 4: Studies occurring after FDA has approved a drug for marketing, efficacy, or optimal use.

Lead Sponsor

The sponsor is the organization or person who oversees the clinical study and is responsible for analyzing the study data.

Northwestern University
Principal Investigator

The person who is responsible for the scientific and technical direction of the entire clinical study.

Principal Investigator Affiliation N/A
Agency Class

Category of organization(s) involved as sponsor (and collaborator) supporting the trial.

Overall Status Recruiting
Countries United States

The disease, disorder, syndrome, illness, or injury that is being studied.

Osteoarthritis of Knee
Additional Details

Achieving optimal prosthetic alignment of the femoral, tibial and patellar components during Total Knee Replacement (TKR) is of great importance as it contributes to better function, less pain and improved quality of life.TKR requires accuracy in the execution of bone cuts in the correct orientation to the coronal, sagittal and axial planes. Malposition potentially leads to increased mechanical stress on the bearing surfaces and inevitably to earlier loosening. Computed Axial Tomography (CT) is the gold standard technique to evaluate implant alignment in the coronal, sagittal and axial planes. As such, CT has imaging has been used to create custom instrumentation with purported likely improvement in surgical outcomes. Customized instrumentation created from a preoperative CT has been shown to be safe and effective, with no reported difference in patient outcomes and similar total knee arthroplasty component alignment. However, taking into consideration CT's high levels of radiation, cost expenses and its inability to obtain images of the limb in weight-bearing position, CT scan cannot be used routinely as a postoperative tool to evaluate TKR implant positioning. The imaging system manufactured by EOS Imaging (formerly Biospace Med, Paris) is a biplanar, low-dose radiation, full body, high resolution, radiological imaging system allowing simultaneous acquisition in the coronal and sagittal planes and in standing position.EOS' main benefits are the considerable reduction in radiation dose (up to 1000 times less than for CT and ten times less than the plain radiography) by using a gaseous detector. George Charpak, the inventor, was awarded the Nobel Prize in 1992 for this work. Moreover, the EOS system can provide 3D images by using the appropriate software algorithms, thus providing a low-radiation alternative to CT.

Arms & Interventions


Other: Manual (tibia) and manual (femur)

Knee replacement with Medacta GMK Sphere implants using manual instrumentation for both the tibia component and the femur component

Other: Manual (tibia) and custom (femur)

Knee replacement with Medacta GMK Sphere implants using manual instrumentation for the tibia component and custom instrumentation for the femur component

Other: Custom (tibia) and custom (femur)

Knee replacement with Medacta GMK Sphere implants using custom instrumentation for both the tibia component and the femur component

Other: Custom (tibia) and manual (femur)

Knee replacement with Medacta GMK Sphere implants using custom instrumentation for the tibia component and manual instrumentation for the femur component


Device: - Medacta GMK Sphere

Contact a Trial Team

If you are interested in learning more about this trial, find the trial site nearest to your location and contact the site coordinator via email or phone. We also strongly recommend that you consult with your healthcare provider about the trials that may interest you and refer to our terms of service below.

Chicago, Illinois




Northwestern Medicine Department of Orthopaedic Surgery

Chicago, Illinois, 60611

Site Contact

Blair Faber

[email protected]