In the past, injuries to the joints, such as the knees, were thought of mainly as just mechanical issues. A torn ligament in the knee leads to instability in the joint. Or a torn meniscus can lead to arthritis as the joint loses its shock absorber. Impact injuries to the joints can lead to bone and cartilage dying off.
However, recent medical research shows that this type of thinking about joint injuries was much too narrow. In reality, when a meniscus in the knee is torn, the body releases pro-arthritis enzymes and factors. This can then stimulate the synovial linings of the joint. The tissues in the joint have been shown to be both biologically and mechanically active.
The factors and enzymes that are released into the joint after injury actually produce a fluid that degrades the joint. The compounds in the fluid break down joint tissue, slow healing, cause swelling and can lead to osteoarthritis.
This new understanding of how joint tissues react when they are injured is leading to new ways to improve joint repair to reduce risk of arthritis later in life. In some cases, repairing the joints after injury can involve the injection of stem cells. Research suggests that a meniscus injury can be at least partially repaired by injecting high amounts of synovial stem cells into the joint.
Overall, understanding the chemical environment that is in the joint tissues has many implications, according to the research. Drugs that often are taken to reduce inflammation for joint injury can slow healing. In some cases, the research suggests that arthritis could even be prevented if modern medicine can discover how to stop the production of the harmful enzymes in the joint right after the injury occurs.