A Multicenter Prospective Randomized Control Study on Persona Total Knee System vs NexGen

Knee replacement is an established treatment for late stage osteoarthritis (OA) of the knee. There is an increasing demand for joint replacement in a younger population. Due to the changing demographics of joint replacement, the population of younger patients are seeking options that not only correct their disease or deformity, but do not limit them in activity. Studies have shown that modern implant designs can potentially improve outcome. Therefore new implants are introduced to the marked with the theoretical benefit of improved implant survival and superior patient reported outcomes. Within Total knee arthroplasty, design changes are introduced in an attempt to improve knee kinematics, functionality and outcome, but those potential improvements need to be evaluated.

The NexGen Total Knee System is a knee replacement system with well a documented performance and has been the device of choice in many institutions. Recently, Zimmer-Biomet have introduced Persona Total Knee system with design changes that include asymmetric tibia plate, increased medial pivoting and more extensive choices in respect to poly thickness, all with the purpose to improve balancing, stability and longevity. Such design changes and proposed benefits need to be evaluated in a prospective clinical trial, with focus on patient safety, satisfaction and implant durability.

The aim is to evaluate intra-operative and postop complications, long-term survivorship and patient reported outcome measures following primary total knee replacement using Persona Cruciate Retaining (CR) total Knee system compared to NexGen Cruciate Retaining (CR) total Knee System.

This project is carried out as a 2-arm randomized controlled single-blinded trial. A total of 314 participants are to be included at 6 centers in Denmark. Participants are seen on an outpatient basis at 3 months and 1 and 2 years postoperatively. After 2-year follow-up the patients will be followed for survivorship through the Danish Knee Arthroplasty Registry.

Inclusion criteria

• Clinical and radiological osteoarthritis of the knee set to receive a primary unilateral total knee replacement
• >18 years of age
• Participants must be able to speak and understand Danish
• Participants must be able to give informed consent and be cognitively intact
• Participants must be able to complete all post-operative controls
• Participants must not have severe comorbidities, American Society of Anesthesiologists (ASA) score ≤ 3
• Clinically suitable to receive a CR implant (no severe deformity and/or ligament instability)

Exclusion criteria

• Terminal illness
• Revision knee replacement surgery
• Rheumatoid Arthritis (RA)
• Traumatic etiology
• Prior surgery on the affected knee that includes osteosynthesis, Anterior cruciate ligament (ACL) and/or Posterior cruciate ligament (PCL) and/or collateral ligament surgery. Arthroscopy with meniscectomy / cartilage surgery / house cleaning is allowed.
• Altered pain perception and / or neurologic affection due to diabetes or other disorders.
• Patients will be excluded intraoperative if CR implant is not suitable.