The operation consists of a mid line incision and then we approach the spine in the gap between the adjacent vertebrae e.g. between L4 and L5. The operation itself involves removing part of the bone (lamina) of the upper vertebra and this then exposes the thickened ligament which is removed. This is a small ligament which runs between the upper and lower vertebrae on each side separately and removal does not weaken the spine in any particular way. Having exposed the nerve which should now be visible a small amount of further ligament and bone is removed from on top of the nerve so that it can be exposed and probed out through the hole (foramen) to make sure the nerve is then free. The wound is then closed in layers.
As with any operation there is a risk of having a general anaesthetic in addition there is a small risk of infection but this is minimised by giving you antibiotics. Blood clots can occur in spinal surgery but are rare and we normally give you elastic support stockings to wear which reduced this to a minimal level. Damage to the nerve that is being decompressed may occur in less than 1%, this could give you either residual leg pain or numbness or weakness usually of the foot which is where this nerve works i.e. a foot drop. There is a serious but very rare chance probably less than 1 in 2000 that the nerve control to the bladder and bowel will be affected causing incontinence of the bladder and bowel. The success rate of this operation is about 75% leaving a possibility that the leg pain would not be improved by the operation but I think one has to look on the positive side.
There is therefore a 70 to 75% probability that your leg pain will be significantly improved by the operation and usually the back is also improved.
Steroid injections sometimes work but often don’t last and in the end there is no alternative to surgery to unblock the nerve. The longer you leave this the more the chance of some permanent nerve damage although this is rare with stenotic problems.
Post Operative Care
After the operation we normally get you up the next day. As I said to you, you may need a catheter inside the bladder if you go into retention and we normally leave this once you are fairly mobile. You will be in hospital several days getting used to walking, sitting and before you leave hospital the physiotherapist will have had you up and down the stairs and once you can do this you will be discharged and need to be seen in 10 days by your practice nurse at the GP surgery for removal of the suture and then a gradual increase of activities up to when we see you usually about six weeks from the operation. You should take any analgesia you need for your back pain during the time that the back is healing. Nerve recovery and leg pain can improve either straight away or gradually over the next few weeks.
You will be encouraged to do regular exercise, going for walks each day and the physiotherapist will give you some exercises while you are in hospital which you should do two or three times a day. Understandably, you should avoid bending, lifting, gardening and heavy house work such as spring cleaning or carrying heavy shopping.