Lumbar surgery in adults can be divided into three general levels of complexity and associated morbidity. The first, an operation to treat herniated lumbar nucleus pulposus, is relatively straightforward from a medical management perspective. The second, an operation for multilevel lumbar stenosis, is usually more involved and tends to be performed for older patients with more comorbidities. The most complicated surgeries are fusion surgeries, which may be carried out with a posterior or anterior approach, or with both approaches.

Patients with a lumbar disc herniation present with radiculopathy in a dermatomal pattern, and may exhibit motor weakness or reflex changes which correspond to the anatomic level of neural compression. The patient is typically a young adult in good health. Axial back pain is not a predominant symptom of this condition and is generally unimproved with a discectomy. If the symptoms produced by lumbar disc herniation fail to respond to appropriate non-operative therapy, laminotomy and discectomy are indicated. Patients are placed either prone or in the knee–chest position on a specially designed operating table; the latter position affords decompression of the abdominal cavity and the epidural veins. The procedure is performed with either loupe magnification or use of the surgical microscope through a posterior midline incision measuring 2.5–5 cm. The operative level is confirmed radiographically to prevent harm to an otherwise normal intervertebral disc. Blood loss is minimal and the total anesthetic time is usually 1–2 hours. A subset of these patients will present with acutely worsening neurologic dysfunction with or without cauda equina syndrome. In these cases, the herniated nuclear fragment is so large that it causes ischemia of the nerve roots. Although unusual, this situation is a true surgical emergency and requires prompt clinical diagnosis to give the patient the best chance of neurologic recovery.