Microdiscectomy (MLD)

Overview and Indications

Microdiscectomy, also called Microlumbar Discectomy (MLD), is performed for patients with a painful lumbar herniated disc. Microdiscectomy is a very common, if not the most common, surgery performed by spine surgeons. The operation consists of removing a portion of the intervertebral disc, the herniated or protruding portion that is compressing the traversing spinal nerve root. Years ago, most spine surgeons would remove a herniated disc using a rather large surgical incision and surgical exposure without the use of a microscope or telescopic glasses, which would often involve a long hospital stay and prolonged recovery period. Today, many surgeons use a microscopic surgical approach with a small, minimally-invasive, poke-hole incision to remove the disc herniation, allowing for a more rapid recovery.

Surgical Technique

The surgery is performed utilizing general anesthesia. A breathing tube (endotracheal tube) is placed and the patient breathes using a ventilator during the surgery. Preoperative intravenous antibiotics are given. Patients are positioned in the prone (lying on the stomach) position, generally using a special operating table with special padding and supports. The surgical region (low back area) is cleansed with a special cleaning solution. Sterile drapes are placed, and the surgical team wears sterile surgical attire such as gowns and gloves to maintain a bacteria-free environment.

A 1-2 centimeter longitudinal incision is made in the midline of the low back, directly over the area of the herniated disc. Special retractors and an operating microscope are used to allow the surgeon to visualize the region of the spine, with minimal or no cutting of the adjacent muscles and soft-tissues. After the retractor is in place, an x-ray is used to confirm that the appropriate disc is identified.

A few millimeters of bone of the superior lamina may be removed to fully visualize the disc herniation. The nerve root and neurologic structures are protected and carefully retracted, so that the herniated disc can be removed. Small dental-type instruments and biting/grasping instruments (such as a pituitary rongeur) are used to remove the protruding disc material. All surrounding areas are also checked to ensure no additional disc fragments are remaining.

The wound area is usually washed out with sterile water containing antibiotics. The deep fascial layer and subcutaneous layers are closed with a few strong sutures. The skin can usually be closed using special surgical glue, leaving a minimal scar and requiring no bandage.

The total surgery time is approximately 1 hour.

Post-Operative Care

Most patients are able to go home the same day or early the next day after surgery. Before patients go home, physical therapists and occupational therapists work with patients and instruct them on proper techniques of getting in and out of bed and walking independently. Patients are instructed to avoid bending at the waist, lifting (more than five pounds), and twisting in the early postoperative period (first 2-4 weeks) to avoid a strain injury or recurrent disc injury. Patients should try to avoid sitting in the same position for more than 45-60 minutes in the first few weeks after surgery. After sitting for 45-60 minutes, patients should get up and stretch or walk for a little bit, then sit down again if desired.

Brace

Patients are generally not required or recommended to wear a back brace after surgery. Occasionally, patients may be issued a small, soft lumbar corset that can provide additional lumbar support in the early postoperative period, if necessary.

Wound Care

The wound area can be left open to air. No bandages are required. Small surgical tapes affixing the suture should be left in place. The area should be kept clean and dry.

Shower/Bath

Patients can shower immediately after surgery, but should cover the incision area with a small bandage and tape, and try to avoid water hitting directly over the surgical area. After the shower, patients should remove the bandage, and dry off the surgical area. Small surgical tapes affixing the suture should be left in place. Patients should not take a bath until the wound has completely healed, which is usually around 2 weeks after surgery.

Driving

Patients may begin driving when the pain level has decreased to a mild level, which usually is between 2-10 days after surgery. Patients should not drive while taking pain medicines (narcotics). When driving for the first time after surgery, patients should make it a short drive only and have someone come with them, in case the pain flares up and they need help driving back home. After patients feel comfortable with a short drive, they can begin driving longer distances alone.

Return to Work and Sports

Patients may return to light work duties as early as 1-2 weeks after surgery, depending on when the surgical pain has subsided. Patients may return to heavy work and sports as early as 4-6 weeks after surgery, if the surgical pain has subsided and the back strength has returned appropriately with physical therapy.

Doctor's Visits and Follow-Up

Patients will return for a follow-up visit to see Dr. Spoonamore or Dr. Smith approximately 8-10 days after surgery. The incision will be inspected and one stitch will be removed. Patients will be given a prescription to begin physical therapy for back exercises, to start 3-4 weeks after the surgery. Medications will be refilled if necessary.

Results and Outcome Studies

The results of microdiscectomy surgery in the treatment of a painful, herniated disc are generally excellent. Numerous research studies in medical journals demonstrate greater than 90-96% good or excellent results from microdiscectomy surgery. Most patients are noted to have a rapid improvement of their pain and return to normal function.

Selected Bibliography

Abramovitz JN, Neff SR. Lumbar disc surgery: results of the Prospective Lumbar Discectomy Study of the Joint Section on Disorders of the Spine and Peripheral Nerves of the American Association of Neurological Surgeons. Neurosurgery 1991;29:301.

Barrios C, Ahmaed M, et al. Microsurgery versus standard removal of the herniated lumbar disc: a 3-year comparison in 150 cases. Acta Orthop Scand 1990;61:399.

Caspar W, Campbell B, et al. The Caspar microsurgical discectomy and comparison with a conventional standard lumbar disc procedure. Neurosurgery 1991;28:78.

Silvers HR. Microsurgical versus standard lumbar discectomy. Neurosurgery 1988;22:837.

Tullberg T, Isacson J, et al. Does microscopic removal of lumbar disc herniation lead to better results than the standard procedure? Results of a one-year randomized study. Spine 1993;18:24.