Nerve Damage
Surgery on the spine that involves the exposure and manipulation of nerves runs the risk of nerve damage.This damage generally falls into  two categories:

• Damage associated with accidental physical external injury such as tearing or crushing or cutting. With modern surgery this form of injury is exceedingly rare. However, even with the best surgical care, the risk is not nil.
  
• Damage not associated with any external physical injury. This form of 'injury' is by far the more common. Because a nerve that is already compressed (as in a disc prolapse) is not 'well',  the nerve cells can be thought of as being 'sick'. Surgical decompression of  the nerve  involves some form of gentle manipulation of the nerve and while this usually does not cause problems, occasionally it is sufficient to make a 'sick' nerve worse. This type of injury is more common when surgery is being performed on a nerve that is already sufficiently compressed to cause some weakness in the muscles that it supplies.

In either case the outcome is usually that there may be some more numbness or weakness in the skin or muscle(s) supplied by that nerve. The disability associated with the weakness will depend on the nerve that is affected as well as the severity of the weakness. The most common post operative weakness  encountered is a partial foot drop. When this happens there is an inability to pull the foot upwards at the ankle. This can usually be managed by a splint and walking is usually almost normal. There are other muscles that can be affected  which can cause more important disabilities that may mean walking with a crutch. These other muscles can include  hip abductor muscles (move the leg away from the body at the hip) or the quadriceps (straightens the knee).

Occasionally nerve 'damage' can cause an increase in pain. This type of pain is usually of the neuropathic type.

Outlook for 'nerve damage'

Generally speaking nerves usually recover. The time frame depends on the type of damage. They will either recover quickly (a few weeks) or will need to regrow. The regrowth of nerves is a slow process and happens at about 1mm per day. It can therefore take 9 -10 months to recover.