A Prospective, Randomized, Single-blinded Clinical Trial Comparing Mechanical Alignment vs Kalipered Kinematic Alignment Total Knee Arthroplasty Using Medacta Spherika

What this Trial Is About

Researchers are comparing two methods of knee replacement surgery for patients with knee osteoarthritis or knee arthropathy. The study evaluates mechanical alignment (MA), which positions the new joint in a neutral alignment that often requires soft tissue adjustments, versus kinematic alignment (KA), which aims to replicate the natural knee alignment without additional soft tissue dissection. This trial addresses mixed results from earlier smaller studies by using the same surgical system and including patient-reported outcomes to better understand which method may lead to improved satisfaction and function. Participants will receive a primary total knee arthroplasty (TKA) using the Medacta SpheriKA system. They will be randomly assigned to either the MA group, where implants are positioned perpendicular to the mechanical axes of the femur and tibia, or the KA group, which restores the pre-arthritic joint surfaces and alignment. Both groups undergo surgery with the same operative modality to ensure a fair comparison. The study will monitor outcomes over time, including standardized scores of knee function and joint awareness. During the study, participants will be assessed using the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS-JR) at 6 weeks after surgery and the Forgotten Joint Score (FJS) at 1 year postoperatively. These evaluations focus on patient-rated outcomes such as pain, function, and joint awareness. Participants must be able to complete questionnaires in English and attend follow-up visits. The trial is designed to monitor results carefully and follow participants for at least one year after their knee replacement surgery.

Mechanical Alignment vs Kalipered Kinematic Alignment Total Knee Arthroplasty