As a rheumatologist, I am literally surrounded by inflammation while at work. Half my patients have active aggressive inflammation inappropriately directed by their immune system. The other half have chronic degenerative musculoskeletal problems. And many actually have both types of musculoskeletal issues. For those with aggressive autoimmune problems that are causing damage and have not responded to conservative measures, modulating their immune system with medication will control the inflammation and control their condition. In this case, inflammation is bad, and treating the root cause of the inflammation is the goal.
Inflammation in degenerative conditions such as osteoarthritis and chronic tendinitis is a much more complicated issue. Studies that look at cartilage and bone in osteoarthritic joints show that there is an overexpression of certain inflammatory cytokines that are thought to cause damage to those joints. Traditional treatments such as steroids and hyaluronic acid injections, and even the newer cell based treatment IRAP (Interleukin 1 Receptor Antagonist Protein) are thought to reduce these inflammatory cytokines and result in pain relief. So decreasing inflammation in degenerative arthritis must be the key. Not necessarily. These treatments result in reduced pain which is a worthy goal. But they don’t fix the problem.
The typical response after an acute injury to a joint, tendon, or ligament is a quick and vigorous inflammatory cascade that brings in lots of different types of cells and cytokines to help repair the acute injury. If this injury is not corrected, this healing inflammatory process stops helping. The usual cells and growth factors that help an acute injury are no longer in position to repair injured tissue. What remains are low levels of cytokines that can cause damage to tissue, mechanical alteration to the joint that causes chronic irritation to the joint and surrounding tissue, and a cyclical process that causes progressive damage and decline in the joint. The theory behind the newer regenerative techniques that are being used such as platelet rich plasma and stem cells is that if you can bring in the cells and growth factors that are most useful for healing, you may be able to restart the healing process by bringing in a targeted inflammatory process. This branch of science is new and exciting. At a minimum it leads me to think that not all inflammation is bad.