lumbar fusion adverse outcomes

This operation involves fusing (stiffening the spine by encouraging bone growth) across the segments of the spine which are thought to be causing symptoms.  Metal rods, screws and cages are used to hold the segments rigid while the fusion takes place (the new bone growth may take up to 6 months).

 The following list covers most of the common and/or serious risks or complications of lumbar fusion. However, you need to remember that the vast majority of patients do not develop any of the problems mentioned below. 

INFECTION: Infections can either be close to the skin surface (superficial) or deep in the wound (deep).  The risk of a superficial wound infection is approximately 5 in 100 (5%).  The risk of a deep infection is less than1 in 100 (1%).  There is a less than 1 in 1000 (0.1%) risk of an infection of the sac containing the nerves (dura) or in the fatty space around the sac (epidural space) or of the disc (disciitis).  Extremely rarely the build up of pus may cause nerve damage and require further surgery to drain the pus.

 NERVE DAMAGE:  The risk of direct surgical damage of the nerves is less than 1 in 1000 (0.01%).  Nerve damage can cause only slight numbness or weakness to total loss of function of the damaged nerve; however, permanent loss of nerve function is very unlikely.  The nerves to the bladder and bowel and for sexual function are the last nerves to leave the spinal canal and therefore bowel and bladder problems and sexual dysfunction may occur if these nerves are damaged.  Unfortunately if nerve deterioration occurs as a result of the surgery it may not be reversible.

 DURAL TEARS:  The sac (dura) containing the nerves can be damaged by the metal screws used in this operation although the risk of this happening is very low.  If the dura is torn you may be required to spend some days after the operation flat in bed.  Very rarely with persisting leakage of the fluid within the sac (CSF) a further operation may be required to stop this. There have been isolated reports of cerebral (brain) haemorrhage occurring after dural tears.

 HAEMATOMA/EPIDURAL HAEMATOMA: Following any surgery excessive bleeding may occur.  The blood may then accumulate and form a clot (haematoma).  The risk of developing a superficial haematoma is less than 5 in 100 (5%).  The risk of a deep haematoma which surrounds the nerves (epidural haematoma) is less than 1 in 1000 (0.1%).  An epidural haematoma may press on the nerves and cause them to stop functioning properly and may necessitate further surgery to remove the blood clot.

Very rarely damage may occur to the large vessels in the front of the spine (aorta and or vena cava).  This may precipitate a surgical emergency and require further sometimes extensive surgery through the abdominal cavity to repair this injury to the vessels.

 FAILURE OF FUSION: Despite trying to encourage bone growth occasionally this does not occur to the extent that is desirable.  This may or may not cause recurrence of symptoms.  Sometimes a further operation to create a sound fusion is required.

 FAILURE OF METALWARE: As bone is more flexible than metal, it is not uncommon for the rods or screws to eventually break.  This DOES NOT cause any major problems in its own right.  It sometimes is an indicator that the fusion is not sound as mentioned above.

 DVT or PE: DVT (Deep Vein Thrombosis) refers to clots forming in the deep veins of the legs.  DVT's which cause symptoms occur in less than 5% (5 in 100) patients.  Clots may travel from the deep veins in the legs and lodge in the blood vessels in the lungs (PE or Pulmonary Embolus).  When this happens it may cause no symptoms at all but occasionally it can cause breathlessness and chest pain.  Extremely rarely, ie, less than 1 in 1000 (0.01%) it can cause sudden death.

 FAILURE TO RELIEVE PAIN: For a number of reasons, some of which are not yet understood, the chance of significantly reducing pain from the lumbar spine after a successful bony fusion operation is approximately 70% at the very best.  A small number of patients may experience increased levels of pain despite a technically satisfactory procedure.

 Please also note that it has been shown that smoking significantly increases the risks and complications of surgery and reduces the chance of a successful outcome.  If you continue to smoke the results are so poor that I usually do not recommend or undertake fusion surgery as a treatment option