In a Japanese study, utilizing the Centers for Disease Control recommendations for antibiotic prophylaxis, an overall rate of 0.7% infection was noted, with a single dose antibiotic group having 0.4% infection rate and multiple dosage antibiotic infection rate of 0.8%. The authors had previously used prophylactic antibiotics for 5 to 7 postoperative days. Based on the Centers for Disease Control and Prevention  guideline, their antibiotic prophylaxis was changed to the day of surgery only. It was concluded there was no statistical difference in the rate of infection between the two different antibiotic protocols. Based on the CDC guideline, a single dose of prophylactic antibiotic was proven to be efficacious for the prevention of infection in lumbar spine surgeries. Epidural post-operative fibrosis
Epidural scarring following a laminectomy for disc excision is a common feature when re-operating for recurrent sciatica or radiculopathy. When the scarring is associated with a disc herniation and/or recurrent spinal stenosis, it is relatively common, occurring in more than 60% of cases. For a time, it was theorized that placing a fat graft over the dural could prevent post operative scarring. However, initial enthusiasm has waned in recent years. In an extensive laminectomy involving 2 or more vertebra, post operative scarring is the norm. It is most often seen around the L5 and S1 nerve roots. Adhesive arachnoiditis
Fibrous scarring can also be a complication within the subarachnoid space. It is notoriously difficult to detect and evaluate.
Neoplasia also includes direct seeding of the cerebrospinal fluid (CSF) from primary central nervous system (CNS) tumors such as glioblastoma multiforme, medulloblastoma, ependymoma, and choroid plexus carcinoma. Strictly speaking, the most common cause of arachnoiditis in failed back syndrome is not infectious or from cancer. It is due to non-specific scarring secondary to the surgery or the underlying pathology. Nerve injury
Laceration of a nerve root, or damage from cautery or traction can lead to chronic pain, however this can be difficult to determine. Chronic compression of the nerve root by a persistent agent such as disc, bone (osteophyte) or scarring can also permanently damage the nerve root. Epidural scarring caused by the initial pathology or occurring after the surgery can also contribute to nerve damage. In one study of failed back patients, the presence of pathology was noted to be at the same site as the level of  surgery performed in 57% of cases. The remaining cases developed pathology at a different level, or on the opposite side, but at the same level as the surgery was performed. In theory, all failed back patients have some sort of nerve injury or damage which leads to a persistence of symptoms after a reasonable healing time. Diagnosis
Avoiding post-laminectomy/laminotomy syndrome
Smaller procedures that do not remove bone (such as Endoscopic Transforaminal Lumbar Discectomy and Reconfiguration) do not cause post laminectomy/laminotomy syndrome. Management
Failed back syndrome (FBS) is a well-recognized complication of surgery of the lumbar spine.