Corticosteroid Injections Damage Cartilage
Clinicians began to treat a variety of joint conditions with corticosteroid injections around 1950. Since clinical improvement was noted, physicians began to use the injections more frequently. Scientists at the University of Montreal were prompted to study effects of steroid injections on cartilage because of reports that a significant number of patients experienced accelerated the joint damage. Researchers chose the rabbit model to study because the rabbit knee is similar to the human knee and they could be microscopically examined for tissue changes.
The researchers injected 25 mg of hydrocortisone over 2 to 12 weeks into rabbit knees and studied the effect on three major components of the joint: proteoglycans (joint proteins that provide structure and lubrication), collagen (the main fiber in cartilage, provides strength and shock absorption) and chondrocytes (The main cells found in cartilage – chondrocytes produce collagen and proteoglycans). As a control, one group of rabbits received weekly saline injections for 12 weeks. (more…)