What is a Lumbar Microdiscectomy operation?
A lumbar microdiscectomy is a commonly performed and routine procedure for lumbar disc prolapse (Fig 1) which causes leg pain (sciatica).
The operation is performed under a general anaesthetic and lasts about one hour. A 2cm skin vertical incision is made in the middle of the lower back. Special retractors are introduced to gently part the fat and muscle layers to reach the bony spine. Using an operating microscope, a 15mm window is made in the ligament and bone layer of the spine to enter the spinal canal, which contains the nerves and the disc prolapse.
The prolapsed disc fragment is carefully removed from under the nerve to relieve the pressure. The main disc space is then entered to check for any other loose fragments, which might cause trouble in the future. Once the nerve is free, the wound is closed with dissolving stitches.
What is the success rate?
The success rate of a lumbar microdiscectomy is approximately 90%, although 5% to 10% will develop another disc prolapse at some stage in the future. A recurrent prolapse may occur immediately after spinal surgery or several years later, although it is most common in the first 3 months after surgery. Patients with a second prolapse have a much higher chance (15% to 20%) of having further prolapses.
Most patients experience complete relief of sciatica within a few hours or days following surgery. In some patients, the pain takes longer to settle due to nerve swelling caused by the disc prolapse.
About 5-10% of patients do not improve or experience worsening symptoms after surgery. In these cases, a repeat MRI scan is usually necessary to check that the nerve remains free of compression.
The overall complication rate for this operation is relatively low and varies between in 2 and 5 % of all patients. Most complications are simple and treatable, such as wound pain, infection, haemorrhage or CSF fluid leak. Other complications such as nerve damage leading to muscle weakness are fortunately very rare.
As part of the consultation and consent for the operation, your surgeon should be able to provide you with details of his/her success and complication rate for the procedure that is being advised.
What is the recovery time?
Patients are usually able to get out of bed for a short walk within 4 - 6 hours of the operation. Most patients are ready to go home within 12 to 24 hours of the operation. The wound may be a little sore for 2 - 3 days but this is easy to manage with regular mild pain medication.
Most patients are able to drive a car within 7 - 10 days and gradually return to normal non-strenuous activities within 2- 3 weeks. Patients with desk-based or non-physical jobs may return to work at 2 to 3 weeks, but a longer period off work is usually advised if the occupation involves heavy physical work.