Bone Mineral Density Changes Under Two Tibial Components in Total Knee Arthroplasty

Laval University

Status and phase: Completed; Phase 4

Conditions: Unilateral Primary Osteoarthritis of Knee

Treatments: Device: Total knee arthroplasty

Study type: Interventional

Funder types: Other; Industry

Identifiers

NCT01764984

5.5.04.12

Details and patient eligibility

About

Osteoarthritis is a progressive disease afflicting to two thirds of Americans. Today, an estimated 43 million individuals have arthritis. By 2020, more than 59.4 million Americans will be affected by the disease. Despite the relative good track record of total knee replacement, it remains a biomedical device that can fail over time. A recent study looking at the current mechanisms of total knee replacement failures, listed polyethylene wear and osteolysis around implants. The material used for polyethylene insert as well as the conformity of articular surface of implants has been modified to decrease wear. While introducing modularity, the usage of metal backing in tibial base plates became obvious as it offered better stress distribution to the proximal tibial bone. However, it introduced other modes of failures. Micromotion has been demonstrated between the metal backing and the tibial liner, and produced backside polyethylene wear in 44% of implants at retrieval for revision. Factor influencing the surgeon's choice of implant include: reproductibility and longevity of results, technical difficulty of implantation, cost, and impact on bone stock. The modulus of elasticity of the tibial base plate has a direct effect on periprosthetic bone biology. Studies have described a significant decrease in postoperative Bone mineral density (BMD), adjacent to the implants, after total knee replacement. No study, to our knowledge, has looked at BMD in vivo after total knee replacement comparing different tibial base plate designs. Direct effect of changes in design on overall implant survival can be studied with randomized clinical trials isolating specific variables. No randomized clinical trial has looked at tibial insert stiffness and modularity, and it effect on bone density changes, synovitis, osteolysis or survivorship. In order to isolate stiffness and modularity as study variables, one would aim at randomizing an homogenous patient population undergoing total knee arthroplasty with implants of similar articular geometry designs with different tibial insert modularity and stiffness.

Full description

Number of patients: 80 Ages: 55 - 75 years old Sex: male and female Race: all

Enrollment: 65 patients

Sex: All

Ages: 55 to 75 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Tri-compartmental knee arthrosis
• 55 to 75 years of age
• Stable health condition

Exclusion criteria

• Inflammatory arthritis
• Osteonecrosis
• Infection
• Amputation (AK or BK)
• Biphosphonates
• Metal in the proximal tibia (25cm)
• History of fracture or osteotomy
• Ligament instability

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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65 participants in 2 patient groups

Trabecular metal

Experimental group

Description:

Primary Total Knee Arthroplasty is performed with a non cemented trabecular metal tibial baseplate.

Treatment:

Device: Total knee arthroplasty

Titanium

Active Comparator group

Description:

Primary total knee arthroplasty is performed with cemented titanium traditional tibial base plate

Treatment:

Device: Total knee arthroplasty