Microdiscectomy vs Nucleoplasty
Low back pain is a very common complaint in middle age and elderly adults that may result in loss of work and dissatisfaction in activities of daily living. A number of patients with low back pain may have herniated or bulging intervertebral discs. The patients frequently complain of low back pain radiating to the buttocks and the back of the thighs, a condition commonly known as sciatica.
The intervertebral discs are present between the vertebral bodies. The disc is designed to cushion the impact of body movements on the spine. The discs consist of an outer dense ring known as annulus fibrosus and an inner soft core known as nucleus pulposus. The nucleus pulposus has a watery consistency which is responsible for the cushioning action of the disc. The annulus fibrosus on the other hand provides structural strength to the intervertebral disc.
The disc in the spine may degenerate with age, especially in the lower back as the region supports the majority of the upper body weight. The outer annulus fibrous ring may develop cracks and fissures due to disc degeneration. The inner nucleus pulposus loses watery content with age which in turn leads to a decrease in the disc height.
The presence of cracks in the outer ring along with increased pressure in the lower back may lead to bulging of the inner nucleus through the ring. The bulging may advance to herniation of the nucleus pulposus or in advanced cases extrusion of the disc contents.
The bulging or herniation may also occur as a result of repetitive action and lifting of a heavyweight without proper support and in a bad posture. The herniation and subsequent loss of disc height may lead to degenerative changes in the involved segment. There may be the formation of bone spurs and facet joint degeneration.
The herniation or bulging may compress the spinal nerve roots exiting or traversing the involved segment. The compression leads to irritation and symptoms of lumbar radiculopathy in the involved nerve root.
Patients may complain of sharp shooting pain in the back or front of the thighs. Some patients may also complain of numbness or tingling in the legs. In severe compression there may be a weakness of the muscles in the lower limbs and patients may have difficulty walking, standing, or climbing stairs. The nerves supplying the involved intervertebral disc and the facet joint are also irritated leading to back pain.
The initial management of discogenic back pain is nonsurgical. The physician may prescribe pain medications such as Tylenol and ibuprofen. Activity modification and posture correction are also recommended along with physical therapy. The patients who do not benefit from nonsurgical methods of treatment for at least 6 weeks may be candidates for surgical management. The type of surgical management depends upon the underlying condition and the severity of the symptoms.
Nucleoplasty is a minimally invasive surgical technique that allows the surgeon to decompress the nerves. Minimally invasive surgery means there is minimum trauma to the structures surrounding the disc while performing the surgery. Nucleoplasty may be performed in an outpatient setting under local anesthesia. The patient remains semi conscious during the procedure while the area where the surgery is performed is anesthetized.
After adequate anesthesia, the surgeon inserts a needle in the involved intervertebral disc. The needle is guided by an external x-ray image intensifier. After the correct position of the needle is verified, the surgeon inserts a thermal-cautery/radiofrequency device. The thermal cautery or the radiofrequency device works by heating the nucleus pulposus.
The heating of the nucleus pulposus leads to shrinkage of the nucleus pulposus (nucleoplasty). The heat generation also leads to the remodeling of the annulus fibrous ring. The shrinkage of the pulposus along with the closure of the cracks leads to relief from disc bulge. After the needle is withdrawn, the entry site is closed with a bandage.
While the heat helps in the shrinkage of the nucleus pulposus, the surrounding tissues such as nerves, muscles, and bone is not damaged. The procedure involves minimum cutting of the tissues leading to a quicker rehabilitation. The patients are able to go home the same day of the procedure.
Microdiscectomy surgery involves a small incision and removal of the herniated disk under the direct vision of the surgeon. The procedure may be performed under general anesthesia in a hospital or in an outpatient setting under local anesthesia. The surgeon carefully separates the tissues to reach the involved spine segment. A small part of the lamina is removed to visualize the intervertebral disc.
The surgeon carefully retracts the spinal nerve roots and punches out small bits of the herniated intervertebral disk. The surgeon may also remove any bone spurs and widen the spinal canal in case of spinal stenosis. The procedure may be performed with an open traditional approach or using an endoscope (minimally invasive technique).
While nucleoplasty is less invasive than microdiscectomy, nucleoplasty can only be performed in limited circumstances. Nucleoplasty is only performed in patients in whom there is a single-level disc bulge. The procedure is limited to patients in whom the cause of symptoms is diagnosed to be solely because of the disk. Similarly, herniation and extrusion of the disc are managed with microdiscectomy rather than nucleoplasty. Nucleoplasty is only used to treat disc bulges with less than 50% loss of diameter.
Microdiscectomy may be combined with laminectomy surgery to relieve symptoms of spinal canal stenosis. Spinal lumbar fusion surgery is better suited in cases of spine instability. Both nucleoplasty and microdiscectomy are highly successful procedures for the management of discogenic pain. Speak with your spine surgeon to determine the procedure best suited for your condition.