Comparison of A Mobile-Bearing Total Knee System With A Fixed-Bearing Total Knee System In Cemented Total Knee Arthroplasty
Condition: Degenerative Joint Disease
MeSH terms: Joint Diseases; Osteoarthritis
Study type: Interventional

Summary: 
      Pain, weakness, instability, and progressive dysfunction are the hallmarks of arthritis of
      the knee. Total knee replacement may frequently be the only therapeutic intervention to
      provide adequate improvement in pain and function. Both fixed bearing and mobile bearing
      knees have a long track record of clinical success. Mobile bearing designs have theoretical
      advantages of decreased contact stresses on the tibial tray, decreased polyethylene wear, and
      improved range of motion relative to fixed bearing designs. These theoretical advantages may
      become especially important in the young patient who requires a knee arthroplasty. This study
      will attempt to see if there is a clinical difference in outcome between mobile bearing and
      fixed bearing knee arthroplasties in patients who require total knee replacement.
    

Detailed description: 
      This prospective, randomized, single-blinded clinical trial compared a mobile-bearing total
      knee system with two types of fixed-bearing total knee systems in patients undergoing
      cemented total knee arthroplasty. The devices to be used are FDA approved: the Sigma Knee
      System (mobile-bearing), the Sigma, Pressfit Condylar posterior cruciate substituting
      (fixed-bearing) system with a metal backed tibial tray, and the Sigma press-fit condylar
      posterior cruciate substituting system (fixed bearing) with an all polyethylene tibial tray.

      The surgical procedures were performed by 4 experienced orthopedic surgeons with a
      subspecialty interest in total knee arthroplasty. A midline skin incision and medial
      parapatellar arthrotomy were used to expose the knee. The distal femoral resection was
      performed with an intramedullary alignment guide, and the proximal tibial resection was
      performed with an extramedullary alignment guide. Knees with fixed deformities had a surgical
      release of the contracted tissues on the medial or lateral side, as appropriate, to obtain
      symmetric balance of the total knee replacement in both flexion and extension. The flexion
      and extension gaps and the medial and lateral soft-tissue structures were balanced in
      accordance with standard techniques.

      Patients began progressive weight-bearing on the first postoperative day, and active knee
      range of motion was initiated with 24 hours after surgery. Patients were typically discharged
      on the fourth or fifth postoperative day after obtaining the ability to walk with a walker,
      to ascend several stairs, and to flex the knee 290 degrees. Patients were asked to return for
      examination and radiographs at 3 months, 1 year, 2 years, and 5 years after surgery.
    

Intervention name(s): Sigma Knee System; Sigma Pressfit Condylar Posterior Cruciate Substituting System with a metal back tibial tray; Sigma Pressfit Condylar Posterior Cruciate Substituting System all polyethylene tray
Intervention type(s): Device; Device; Device
Intervention description(s): Sigma Knee System (mobile-bearing knee with the P.S. polyethylene insert); Sigma Pressfit Condylar Posterior Cruciate Substituting System with a metal back tibial tray (fixed-bearing knee with the metal backed tray); Sigma Pressfit Condylar Posterior Cruciate Substituting System (fixed bearing with an all polyethylene tray)
Other intervention name(s): Sigma Rotating Platform Knee System; Press-Fit Condylar Total Knee Arthroplasty
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Treatment
Keywords: knee arthroplasty