Scar tissue forms mostly in muscles, tendons, ligaments, fascia and joints. These dead fibrotic tissues can also be called an adhesion.
Repetitive motion, injury and surgery can result in the formation of scar tissue. The bodies healing process occurs in three stages when a muscle, tendon or ligament is torn. These three stages are called the inflammatory response which includes: acute inflammation, repair, and remodeling.

Swelling, redness, heat and pain occur during the acute inflammation stage which lasts for approximately 72 hours. The repair process begins after the inflammation recedes. Rather than forming brand new tissue the damaged tissue will heal with the formation of scar tissue.
An injury or a repetitive motion such as typing may cause a muscle to tighten up. When the muscle tightens up, welling occurs which restricts the oxygen supply to the muscles and connective tissues. Scar tissue or adhesions can form from this lack of oxygen.
After a surgery the body has the natural ability to heal itself. As a result of the incision to the skin the body will produce connective tissues, adhesions (scar tissue) and collagen to replace damaged material. This scar tissue serves the purpose of replacing the damaged cells at the point of incision or injury. Lacking pigmentation and hair skin scar tissue is much different than scar tissue found in the fascial layers of the body. Deep scar tissue in the fascial layers of the body develops adhesions or spider like web threads to help the body heal and recover.
Epidural fibrosis is the formation of scar tissue near the nerve root. After back surgery this scar tissue formation is a common occurrence. Patients with successful surgical outcomes along with patients who have continued back pain and leg pain will experience epidural fibrosis. Postoperative pain is often called failed back surgery syndrome. The importance of scar tissue as the pain is controversial.
Scar tissue in itself is not painful seeing as the tissue contains no nerve ending. The ways that scar tissue can cause back pain or leg pain is by creating tethers or binding the lumbar nerve. With this thought in mind, although the topic is controversial, I am led to believe that scar tissue is not the actual cause of the pain, but the binding of the scar tissue to the lumbar nerve is. With this in mind, the scar tissue is still the problem.
Six to Twelve weeks after back surgery is the typical amount of time that it takes for epidural fibrosis (scar tissue) to form. The epidural fibrosis is often preceded by a period of initial pain relief. After this initial period of relief the patient slowly develops recurrent back pain or leg pain. With back surgery sometimes the improvement will start immediately after the surgery. Occasionally the nerve will heal more slowly if there is nerve damage from the original pathology.
After the surgery if the patient still continues to feel back pain or leg pain but the pain starts to improve over the next three months, that patient should continue to improve. The spine surgery is most likely not a success if the patient feels or sees no improvement by three months postoperatively. Unfortunately the patient will continue to feel back pain and leg pain.