Prolotherapy involves the treatment of two specific kinds of tissue: tendons and ligaments. A tendon attaches a muscle to the bone and involves movement of the joint. A ligament connects two bones and is involved in the stability of the joint. A strain is defined as a stretched or injured tendon; a sprain, a stretched or injure ligament. Once these structures are injured, the immune system is stimulated to repair the injured area. Because ligaments and tendons generally have a poor blood supply, incomplete healing is common after injury. This incomplete healing results in these normally taut, strong bands of fibrous or connective tissue becoming relaxed and weak. The relaxed and inefficient ligament or tendon then becomes the source of chronic pain and weakness.
The greatest stresses to the ligaments and tendons are where they attach to the bone, the fibro-osseous junction. The most sensitive structures that produce pain are the periosteum (covering of the bone) and the ligaments. It is important to note that in the scale of pain sensitivity (which part of the body hurts more when injured), the periosteum ranks first, followed by ligaments, tendons, fascia (the connective tissue that surrounds muscle), and finally muscle. Cartilage contains no sensory nerve endings. If you are told that your cartilage is the cause of your pain, you have been misinformed; the cartilage cannot hurt because they contain no pain sensing nerves. If there is cartilage damage, the ligaments are typically the structures that hurt. Ligaments are weakest where they attach to bone. The periosteum is the most sensitive area to pain and the ligaments second. It is now easy to understand why this area hurts so much. This is where the Prolotherapy injections occur, and thus eliminate the chronic pain of many conditions including arthritis, mechanical low back pain, degenerative disc disease, cartilage injury, and sports injuries.
Prolotherapy works by exactly the same process that the human body naturally uses to stimulate the body's healing system, a process called inflammation. The technique involves the injection of a proliferant (a mild irritant solution) that causes an inflammatory response which "turns on" the healing process. The growth of new ligament and tendon tissue is then stimulated. The ligaments and tendons produced after Prolotherapy appear much the same as normal tissues, except that they are thicker, stronger, and contain fibers of varying thickness, testifying to the new and ongoing creation of tissue. The ligament and tendon tissue which forms as a result of Prolotherapy is thicker and stronger than normal tissue, up to 40% stronger in some cases!