Related Experiment Video
Updated: Aug 8, 2026
07:32
Standardized Histomorphometric Evaluation of Osteoarthritis in a Surgical Mouse Model
Published on: May 6, 2020
Microscopic change in macroscopically normal equine cartilage from osteoarthritic joints
Rachel E Weaver1, Mo Sharif, Laurene A Livingston
1Department of Anatomy, Southwell Street, University of Bristol, Bristol, United Kingdom.
Connective Tissue Research
|June 7, 2006
Summary
Even macroscopically normal cartilage from joints with osteoarthritis shows microscopic changes. This indicates that osteoarthritis affects all articular cartilage, not just visibly damaged areas, impacting chondrocyte expression.
Area of Science:
- Veterinary Medicine
- Biochemistry
- Orthopedics
Background:
- Osteoarthritis (OA) is a degenerative joint disease affecting articular cartilage.
- Macroscopic assessment of cartilage in OA may not reveal early-stage microscopic changes.
- Understanding sub-clinical changes in articular cartilage is crucial for early OA detection and management.
Purpose of the Study:
- To compare histological features of macroscopically normal articular cartilage from healthy joints versus joints with focal OA lesions.
- To investigate chondrocyte expression of specific cytokines and receptors in relation to OA.
- To determine if microscopic changes exist in seemingly normal cartilage within OA-affected joints.
Main Methods:
- Articular cartilage from equine joints (metacarpophalangeal, proximal and distal interphalangeal) was collected post-euthanasia.
- Cartilage was categorized into macroscopically normal from healthy joints (control) and macroscopically normal from OA-affected joints.
- Immunohistochemistry was used to quantify chondrocytes expressing interleukin-1 beta, interleukin-18, and interleukin-18 receptor across cartilage zones.
- Histology scores for glycosaminoglycan loss were assessed.
Main Results:
- Articular cartilage from OA-affected joints (Group 2) showed significantly increased interleukin-1 beta expression in superficial and middle zones compared to controls (Group 1).
- Interleukin-18 receptor expression was significantly higher in the superficial zone of Group 2 cartilage.
- A positive correlation was observed between OA grade and chondrocyte expression of interleukin-1 beta, interleukin-18, and interleukin-18 receptor.
- Histological assessment revealed significantly greater glycosaminoglycan loss in Group 2 cartilage.
Conclusions:
- Macroscopically normal articular cartilage from joints with focal osteoarthritis lesions exhibits significant microscopic changes.
- These changes include increased expression of pro-inflammatory cytokines and receptors, and glycosaminoglycan loss.
- The findings suggest that all articular cartilage within an OA-affected joint may be involved in the disease process, even if appearing normal.
