A Roentgen Stereophotogrammetric Analysis on Migration of Knee Prostheses. (Ti-Tan)

This study has been completed.
Sponsor:
Collaborators:
Aarhus University Hospital
Zimmer, Inc.
Information provided by:
University of Aarhus
ClinicalTrials.gov Identifier:
NCT00138853
First received: August 29, 2005
Last updated: October 12, 2010
Last verified: October 2010
  Purpose

The purpose of this study is to compare the early migration of two uncemented total knee arthroplasties with different metal coating. Only the tibial prosthesis plateau varies. One is made out of tantalum and has two short pegs for fixation into the tibia while the other is covered by titanium fiber-mesh on the bone-near site and has 4 short pegs for screw fixation into the tibia.


Condition Intervention
Osteoarthritis
Device: Tibial component

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Single Blind (Subject)
Primary Purpose: Treatment
Official Title: A Roentgen Stereophotogrammetric Analysis on Migration of Knee Prostheses. A Randomised Prospective Study of Tantalum Versus Titanium Implants.

Resource links provided by NLM:


Further study details as provided by University of Aarhus:

Primary Outcome Measures:
  • Tibial implant migration evaluated by RSA. [ Time Frame: 2008 ] [ Designated as safety issue: Yes ]

Secondary Outcome Measures:
  • Comparison of Model Based vs. Marker Based RSA for analysis of these uncemented implants. [ Time Frame: 2008 ] [ Designated as safety issue: No ]

Enrollment: 50
Study Start Date: November 2003
Study Completion Date: April 2007
Primary Completion Date: April 2007 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Tantalum knee
Tantalum Tibial component, uncemented
Device: Tibial component
Tibial component inserted at the time of surgery
Other Names:
  • NexGen Tantalum Tibial Plate
  • NexGen Titanium Tibial Plate, screw fixed
Active Comparator: Titanium Knee
Titanium Tibial Component, screw fixed
Device: Tibial component
Tibial component inserted at the time of surgery
Other Names:
  • NexGen Tantalum Tibial Plate
  • NexGen Titanium Tibial Plate, screw fixed

Detailed Description:

Around 4% of total knee arthroplasties (TKA) are revised 15 years after the primary operation, most due to loosening of the implant. The use of uncemented prostheses are expected to extend the fixation time and thereby the years of TKA survival. When a cementless implant is inserted, direct bone ingrowth to the implant depends on a complete primary stabilisation. Movement between the bone and implant will cause a fibrous membrane leading to micromotions. Micromotions can be evaluated by radiophotogrammetric analysis (RSA) in early follow-up and they have been shown to be a prognostic marker for painful loosening of the implant.

Tantalum is a fairly new biomaterial designed with a high and bone-binding porosity. Tantalum has already proven to be a good prosthesis material facilitating fast bone-ingrowth and supplying mechanical qualities in the bone-prosthesis interface that surpasses the qualities of regular prosthesis materials by uncemented method. Titanium on the other hand has been used as a prosthesis coating for years and also promote prosthesis fixation by osteointegration.

The purpose of this study is to compare the early migration of two uncemented total knee implants with different metal coating and fixation method. Only the tibial prosthesis plateau varies in design. One plateau is a 2 pegged tantalum monobloc and the other plateau is a modular titanium fiber-mesh coating with 4 short pegs for screw fixation into the tibia.

Furthermore the extend of the expected micromovements between the polyethylene liner and the metal backing of the titanium plateau will be compared to the stable tantalum monobloc.

Theoretically tantalum should allow a more optimal coating for bone ingrowth, but as primary stability is also important for longterm prostheses survival the method of primary fixation could alså play a role.

To evaluate both the plateau-bone micromotions and the polyethylene-prosthesis micromovements metal markers have been placed on the prosthesis pre-operatively and furthermore into the tibial bone and into the tibial polyethylene during surgery allowing us to evaluate stereo x-rays by a photogrammetric analyses called RSA at the Orthopaedic Center, Aarhus University Hospital. Follow-up stereo x-rays will be scheduled for 1 week, 3 months, 6 month, 1 years and 2 years post-surgery.

  Eligibility

Ages Eligible for Study:   18 Years to 70 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  1. Patients with one- or double-sided primary knee arthrosis.
  2. Patients with a sufficient bone quality for implantation of an uncemented prosthesis.
  3. Informed and written patient consent.

Exclusion Criteria:

  1. Patients with neuromuscular or vascular diseases in the affected leg.
  2. Patients who peroperatively are estimated unsuitable for an uncemented knee arthroplasty e.g. due to bone cysts or dilution of the bone mass.
  3. Patients who use non-steroid anti-inflammatory drugs (NSAID) and cannot refrain from taking them postoperatively (this includes COX-2-inhibitors).
  4. Patients with osteoporosis estimated from the preoperative x-ray or former diagnosis of osteoporosis.
  5. Patients with fracture sequelae.
  6. Women, who are pregnant or are at risk of getting pregnant.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00138853

Locations
Denmark
Orthopaedic Center, Aarhus University Hospital.
Aarhus, Denmark, 8000
Sponsors and Collaborators
University of Aarhus
Aarhus University Hospital
Zimmer, Inc.
Investigators
Principal Investigator: Kjeld Søballe, MD, Prof. Orthopaedic Center, Aarhus University Hospital, Tage-Hansens Gade 2, 8000 Aarhus C, Denmark.
  More Information

No publications provided

Responsible Party: Professor Kjeld Soballe, Aarhus University Hospital, Tage-Hansens Gade 2, 8000 Aarhus C
ClinicalTrials.gov Identifier: NCT00138853     History of Changes
Other Study ID Numbers: 20030119
Study First Received: August 29, 2005
Last Updated: October 12, 2010
Health Authority: Denmark: The Danish National Committee on Biomedical Research Ethics

Keywords provided by University of Aarhus:
RSA
Genoarthrosis
Knee arthroplasty
Micromotion of polyethylene liner

Additional relevant MeSH terms:
Osteoarthritis
Arthritis
Joint Diseases
Musculoskeletal Diseases
Rheumatic Diseases

ClinicalTrials.gov processed this record on September 14, 2014