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Roentgen Stereophotogrammetric Analysis (RSA) Trial Comparing Trabecular Metal Monoblock and Modular Tibial Components

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified August 2015 by Michael Dunbar, Dalhousie University.
Recruitment status was:  Active, not recruiting
Zimmer Biomet
Information provided by (Responsible Party):
Michael Dunbar, Dalhousie University Identifier:
First received: August 11, 2010
Last updated: August 6, 2015
Last verified: August 2015

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.

Condition Intervention Phase
Osteoarthritis Device: Trabecular Metal Modular Tibial Total Knee Component Device: Trabecular Metal Monoblock Tibial Total Knee Component Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Randomized Control Study Using Roentgen Stereophotogrammetric Analysis (RSA) to Compare the Fixation of the Trabecular Metal Monoblock and the Trabecular Metal Modular Total Knee Arthroplasties

Further study details as provided by Michael Dunbar, Dalhousie University:

Primary Outcome Measures:
  • micromotion of tibial component as measured with RSA [ Time Frame: 2 years postoperative ]

Secondary Outcome Measures:
  • Bone mineral density around the tibial component [ Time Frame: 2 years postoperative ]
  • Subjective health outcome questionnaires - SF36, WOMAC, Oxford12 knee, Pain and Catastrophizing Scale, Standardized comorbidity questionnaire [ Time Frame: 2 years postoperative ]

Estimated Enrollment: 50
Study Start Date: February 2011
Estimated Study Completion Date: September 2016
Estimated Primary Completion Date: September 2016 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Trabecular Metal Modular Tibial Total Knee Component
Device: Trabecular Metal Modular Tibial Total Knee Component
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.
Trabecular Metal Monoblock Tibial Total Knee Component
Device: Trabecular Metal Monoblock Tibial Total Knee Component


Ages Eligible for Study:   21 Years to 80 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Symptomatic osteoarthritis of the knee indicating surgical intervention
  • Between the ages of 21 and 80 inclusive
  • Ability to give informed consent

Exclusion Criteria:

  • Significant co-morbidity affecting ability to ambulate
  • Flexion contracture greater than 15°
  • Extension lag greater than 10°
  • Tibial subluxation greater than 10 mm on standing AP radiograph
  • Prior arthroplasty, patellectomy or osteotomy with the affected knee
  • Lateral or medial collateral ligament instability (> 10° varus/valgus)
  • Leg length discrepancy greater than 10 mm
  • Active or prior infection
  • Morbid Obesity (BMI > 40)
  • Medical condition precluding major surgery
  • Severe osteoporosis or osteopenia
  • Neuromuscular impairment
  Contacts and Locations
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Please refer to this study by its identifier: NCT01180595

Canada, Nova Scotia
Halifax Infirmary
Halifax, Nova Scotia, Canada, B3H 3A7
Sponsors and Collaborators
Dalhousie University
Zimmer Biomet
Principal Investigator: Michael J Dunbar, MD PhD Dalhousie University and CDHA
  More Information

Responsible Party: Michael Dunbar, MD, PhD, Dalhousie University Identifier: NCT01180595     History of Changes
Other Study ID Numbers: CDHA-RS/2011-010
Study First Received: August 11, 2010
Last Updated: August 6, 2015

Keywords provided by Michael Dunbar, Dalhousie University:
knee joint
Bone Density
Outcome Assessment (Health Care)

Additional relevant MeSH terms:
Joint Diseases
Musculoskeletal Diseases
Rheumatic Diseases processed this record on August 22, 2017