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

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.

Conditions

• Osteoarthritis

Interventions

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.

DEVICE

Trabecular Metal Monoblock Tibial Total Knee Component

Sponsors & Collaborators

• Zimmer Biomet

  collaborator INDUSTRY

• Dalhousie University

  lead OTHER

Principal Investigators

• Michael J Dunbar, MD PhD · Dalhousie University and CDHA

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

21 Years

Max Age

80 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2011-02-28

Primary Completion

2019-09-30

Completion

2019-09-30

Countries

• Canada

Study Locations