Lumbar Hemilaminectomy Surgery
The lamina forms the roof of the spinal canal that forms the conduit for the spinal cord/thecal sac. The lamina is present at the back of the spinal cord/thecal sac whereas the vertebral body and the intervertebral discs are present at the front. The spinal nerve roots exit the spinal column at each segment through the intervertebral foramen.
As the spinal nerves exit the foramen they may be compressed or irritated due to narrowing or stenosis of the canal. Bone spurs may form that may compress the neural structures. The bone spurs may form as a part of age-related wear and tear of the spine or secondary to trauma. There may be thickening of the lamina which may cause compression of the neural structures.
The patients requiring lumbar hemilaminectomy surgery may present with complaints of back pain, radiating pain in the buttocks, radiating pain in the back of the thigh or front of the thighs. Patients may also complain of numbness and tingling in the lower extremities. Some patients may have difficulty walking due to pain and may have an exacerbation of symptoms while walking downhill or when bending backward.
The symptoms may initially be managed conservatively in the form of pain medications and physical therapy. In patients with continuous symptoms, an epidural corticosteroid or a nerve block injection may be tried. Only in patients with continued symptoms despite conservative management, surgical management is indicated. Patients with the instability of the spine segment and deformity are usually candidates for lumbar fusion surgery.
Lumbar hemilaminectomy surgery is usually performed under general anesthesia. The patient lies with his/her back facing the surgeon. The surgeon gives a small incision in the back and carefully retracts the paraspinal muscles.
An endoscope/microscope may be used to perform the surgery through a very small incision. The surgeon then reaches the lamina and removes a small part of the lamina to decompress the spinal canal and remove the compression from the spinal nerves.
Along with the removal of a part of the lamina, the surgeon may also remove a part of ligamentum flavum which may be thickened and causing narrowing of the precarious neural space. The surgeon may also proceed to remove parts of the intervertebral disc. After decompressing the neural structure, the surgeon closes the incision in layers.
The Patients may be required to stay overnight and are usually discharged the next day of the procedure. The steri-strips or the dressing may be removed after 10 days and patients usually require analgesics only for a few days to manage post-operative pain.
The hemilaminectomy surgery helps to relieve the symptoms of compression of the neural structures but like other surgeries, hemilaminectomy may be associated with some complications.
The complication following hemilaminectomy may occur in the form of failure to adequately decompress, accidental durotomy, damage to the nerve/thecal sac, bleeding, infection, etc. The surgery may fail to relieve back pain, known as failed back surgery.
The patients are usually advised physical therapy after the initial healing period to strengthen the back muscles and increase flexibility. The majority of the patients experience excellent relief from their symptoms after hemilaminectomy. The rehabilitation is quicker than the lumbar laminectomy due to fewer cutting of the tissues.
However, not all patients are candidates for hemilaminectomy. Patients with extensive involvement and compression may benefit from laminectomy surgery or lumbar fusion surgery.