The formation of scar tissue near the nerve root (also called epidural fibrosis) is a common occurrence after back surgery—so common, in fact, it is so common that it often occurs for patients with successful surgical outcomes as well as for patients with continued or recurrent leg pain and back pain. For this reason, the importance of scar tissue (epidural fibrosis) as a potential cause of postoperative pain—commonly called failed back surgery syndrome—is controversial.

Scar tissue formation is part of the normal healing process after a spine surgery. While scar tissue can be a cause of back pain or leg pain, in and of itself the scar tissue is rarely painful since the tissue contains no nerve endings. Scar tissue is generally thought to be the potential cause of the patient's pain if it binds the lumbar nerve root with fibrous adhesions.

diagnosis

If a patient suffers from continued back pain and/or leg pain after discectomy or laminectomy surgery, a comprehensive physical examination and appropriate diagnostic imaging techniques can often pinpoint the cause of pain. In addition, there are a few things that can be done before and/or after spine surgery that have the potential to limit the formation of scar tissue over the operative disc.

A comprehensive physical examination and appropriate diagnostic imaging techniques can often pinpoint the responsible pathology - the underlying cause - of the patient's pain. For instance, a definitive diagnosis of recurrent disc herniation or other disorders may be made.

In a number of cases, however, an MRI scan reveals only the presence of scar tissue as a remarkable finding, suggesting to some clinicians and researchers that the scar tissue is the likely source of the continued back pain and/or leg pain after lower back surgery. As mentioned above, although almost all postoperative MRI scans show scar tissue, postoperative pain for most patients probably has little to do with the scar tissue.

symptoms

Typically, symptoms associated with epidural fibrosis (scar tissue around the nerve root) appear at 6 to 12 weeks after back surgery. This is often preceded by an initial period of pain relief, after which the patient slowly develops recurrent leg pain or back pain. Sometimes, the improvement occurs immediately after back surgery, but occasionally the nerve damage from the original pathology (cause of the patient's pain) makes the nerve heal more slowly.

In general, if the patient experiences continued leg pain or back pain directly after spine surgery, but starts to improve over the next three months, he or she should continue to improve. If, however, there is no improvement by three months postoperatively, the spine surgery is unlikely to have been successful, and the patient will continue to have back pain or leg pain.

Causes of Pain after Failed Back Surgery

At this point, the physician and patient will need to take a fresh look at the problem to exclude other causes of postoperative pain.

• Improper preoperative patient selection before back surgery.This is the most common cause of failed back surgery syndrome. Surgeons look for an anatomic lesion in the spine that they can correlate with a patients pain pattern. Some lesions are more reliable than others. For example, degenerative disc disease is less commonly correlated with patients back pain than leg pain from a disc herniation pinching a nerve root. There are other sources of pain that can mimic back pathology such as piriformis syndrome, sacroiliac joint dysfunction and hip pathology (such as hip osteoarthritis)

• Recurrent disc herniation after spine surgery. This is another common cause of recurrent pain after a discectomy/microdiscectomy spine surgery. The typical clinical picture is one where the patient initially has substantial pain relief, followed by a sudden recurrence of leg pain. In contrast to symptomatic pain caused by scar tissue (epidural fibrosis), in which symptoms tend to appear gradually, the symptoms of recurrent disc herniation tend to occur acutely. In addition to clinical history and presentation, an MRI scan is also useful in distinguishing the two pathologies.

• Technical error during spine surgery. The spine surgeon must also consider technical error if there is continued pain after a discectomy or microdiscectomy or a laminectomy. For example, was a fragment of herniated disc material missed, or a piece of bone left adjacent to the nerve? In either case, the resulting compression of the nerve root could cause pain. Were the correct operative levels chosen during surgical planning? If not, an adjacent disc may be the true source of the pain. Again, postoperative imaging and clinical presentation will help answer these questions.

Treatment Options for Pain After Back Surgery

· Stretching Exercise

Stretching the nerve root while the body is healing (scarring in) after back surgery can help limit epidural fibrosis from becoming a clinical problem. Most scar tissue forms within the first 6 to 12 weeks after back surgery. The theory is that if the nerve is kept mobile while the wound heals, the nerve will not be bound down by adhesions and the scar tissue that develops should not become a problem. For example, routinely pumping the ankle while stretching the hamstrings, the large muscle running down the back of each thigh, will move the nerve across the operative disc site in the low back and help prevent it from scarring down.

• Manual techniques - manipulation of affected areas by applying force to the joints, muscles, and ligaments. Some evidence for the effectiveness of certain techniques is available.
•  Electrotherapy - the most commonly known form of electrotherapy is transcutaneous electrical nerve stimulation (TENS). TENS therapy attempts to reduce back pain by means of a low-voltage electric stimulation that interacts with the sensory nervous system. Randomized controlled trials have yielded either positive or neutral results regarding the efficacy of TENS as a treatment for back pain.

 Medication treatment

Pain relievers and related drugs are used at every stage of the medical treatment of back pain, The most common noninvasive pharmacologic treatments for chronic back pain are:

• Analgesics - or pain medications, including acetaminophen.
• Nonsteroidal anti-inflammatory agents (NSAIDs) - includes aspirin, ibuprofen, naproxen and COX-2 inhibitors.
• Muscle relaxants - used to treat muscle spasms due to pain and protective mechanisms.
• Narcotic medications - most appropriate for acute or post-operative pain.
• Antidepressants and anticonvulsants - used to treat neuropathic ("nerve") pain.
• Neuromodulating medications - used to treat neuropathic and muscular pain.

• Injections Injections provide direct delivery of steroids or anesthetic into joints, ligaments, muscles, or around nerves. These injections may provide relief of pain (often temporary) and can be used to confirm if the injected structure is the source of the pain, clarifying the diagnosis. Epidural injections can provide temporary relief for upper extremity or lower extremity pain due to a pinched nerve in the spine.

• Radiofrequency radioablation لیزر کم توان
  This procedure involves deadening of painful nerves via heat administered through a small needle. In carefully selected patients, this helps in approximately 60% of patients and lasts for months to years.

• Repeat surgery

If the recurrent pain appears years after spine surgery, it is unlikely that the pain is due solely to scar tissue. Scar tissue does not continue to form years after spine surgery, so it is generally not considered a cause of late recurrent pain. Rather, the nerve may be compressed, or “tethered”, by a small disc herniation or by new bone growing near the nerve (stenosis).

The clinical presentation of a tethered nerve includes a positive straight leg-raising test (i.e., lifting the leg causes increased pain down the leg). In such cases, repeat decompression or discectomy surgery will usually lead to good results.