Roentgen Stereophotogrammetric Analysis (RSA) Trial Comparing Trabecular Metal Monoblock and Modular Tibial Components
Condition: Osteoarthritis
MeSH terms: Osteoarthritis
Study type: Interventional
Phase: Phase 4

Summary: 
      Total knee replacement is an effective option for treating chronic knee conditions that cause
      pain and functional impairment. Significant improvements in quality of life, as measured by
      both disease specific and generic quality of life measures have been well documented.
      Carefully monitored introduction of new implant designs through small, randomized trials
      using radiostereometric analysis (RSA) is gaining support. RSA is a radiographic technique
      that uses small tantalum balls implanted into the patient's bone to measure micromotion (<1
      mm) at the bone - implant interface, something which is not possible to do reliably using
      regular x-ray techniques. The amount of micromotion that occurs within 2 years of surgery can
      be used to predict the long term survival of knee replacements. This provides a method for
      detecting inferior implant designs using only a small number of patients before release of
      these products into large clinical trials.

      The study purpose is to utilize RSA to compare the migration patterns of the Trabecular
      Metal(TM) Monoblock and the TM Modular Total Knee Arthroplasties during the first two postop
      years and to determine what proportion of cases achieve adequate fixation. Secondary outcome
      measures will be recorded to quantify changes in functional status of subjects after surgery
      and bone mineral density will be monitored to quantify any changes around the implant.
      Migration patterns will be compared to results obtained from previous studies of uncemented
      and cemented total knee arthroplasty components conducted at this centre.

      Null Hypothesis: There is no significant difference in micromotion patterns of the TM
      arthroplasty components of the monoblock design and the modular design.

      Alternative Hypothesis: There are significant differences in micromotion patterns between the
      tibial components of the monoblock design and the modular design.

      This is a consecutive sample randomized control trial of patients undergoing total knee
      arthroplasty with the TM Monoblock and TM Modular Knee Arthroplasty systems utilizing RSA to
      identify the migration patterns of the tibial components of the implant. DEXA scanning will
      also be conducted to determine changes in the bone mineral density adjacent to the implant.
      Health status and functional outcome measures will be recorded to quantify functional status
      of subjects before surgery and at each follow-up interval. Gait will be monitored and
      analyzed preoperatively and postoperatively throughout the duration of the trial.
    


Intervention name(s): Trabecular Metal Modular Tibial Total Knee Component; Trabecular Metal Monoblock Tibial Total Knee Component
Intervention type(s): Device; Device
Intervention description(s): The modular design of the Trabecular Metal Total Knee allows for increased options for physicians however, it is not clear how this modular feature will affect fixation since it may compromise some of the advantages of the original TM Monoblock tibial component.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment
Keywords: osteoarthritis; arthroplasty; knee joint; radiography; surgery; Bone Density; Outcome Assessment (Health Care)