What is the main difference between tendonitis of the elbow or osteoarthritis of the elbow?

Soft tissue vs. bony: Tendinitis is an inflammatory process of a tendon. It is a soft tissue problem that usually occurs outside of a joint. Osteoarthritis is a degenerative process involving the joint. The cartilage covering the ends of the bones is wearing out. As the cartilage wear out the bone may start to rub and cause pain. In advanced oa bony spurs may form and te joint may not move as well as well.

Different problems: Tendons connect muscles to bones and obviously some tendons will connect to the bones of a joint such as the elbow. Tendinitis of the elbow is inflammation of the tendons that connect to the elbow with 2 examples being golfers and tennis elbows. Osteoarthritis is a true joint disease. It is in the joint itself, while the tendons surround the joint. Obviously pain can be the main symptom of both.

Muscle Vs Bone: Osteoarthritis is a degenerative joint disease problem, meaning bone and cartilage wear and tear. Tendonitis is a soft tissue injury where muscles attach to bone, those attachments are the tendon and can get irritated due to tears or stretching of these tissues.