Abstract
The purpose of the current study was to investigate the feasibility of the application of defect-size femoral implants in a rabbit model of established cartilage defects and compare this treatment to microfracturing. In 31 New Zealand White rabbits, a medial femoral condyle defect was created in each knee. After 4 weeks, 3 animals were killed for defect baseline values. In the other 28 rabbits, knees were sham-operated, treated with microfracturing, or treated by placing an oxidized zirconium (OxZr) or cobalt-chromium (CoCr) implant (theta articulating surface 3.5 mm; fixating pin of 9.1 mm length). These animals were sacrificed 4 weeks after treatment. Joints were evaluated macroscopically. Implant osseointegration was measured by automated histomorphometry, and cartilage repair was scored microscopically. Cartilage quality was analyzed macroscopically and microscopically. Bone-implant contact was 63.2% +/- 3.2% for CoCr and 62.5% +/- 3.2% for OxZr. Cartilage defects did not show complete healing, nor during subsequent sham-surgery or microfracturing. For all treatments, considerable cartilage damage in the articulating medial tibia, and degeneration of lateral tibial and femoral cartilage was observed (p < 0.05). Both CoCr and OxZr implant-treated defects showed an increase of cartilage degeneration compared to microfracturing and sham-operated defects (p < 0.05). Although only a single short-term follow-up period was investigated in this study, caution is warranted using small metal implants as a treatment for established localized cartilage defects because, even after 4 weeks in this model, the metal implants caused considerable degeneration of the articulating surface.
Original language | English |
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Pages (from-to) | 84-90 |
Number of pages | 7 |
Journal | Journal of Orthopaedic Research |
Volume | 27 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2009 |
Keywords
- Animals
- Biocompatible Materials/chemistry
- Biomechanical Phenomena
- Cartilage, Articular/pathology
- Chromium/chemistry
- Cobalt/chemistry
- Female
- Femoral Fractures/pathology
- Fracture Healing
- Osseointegration
- Prostheses and Implants
- Rabbits
- Tibial Fractures/pathology
- Time Factors
- Zirconium/chemistry