Whilst the majority of patients have no problems at all around the time of an operation, there are known risks associated with spinal surgery. The risks and complications listed below are some of the more common risks associated with spinal procedures. However, this list may not be exhaustive and Mr Morris will discuss specific risks regarding your procedure in clinic prior to the operation.
Anaesthetic problems – these will be discussed with you by the anaesthetist prior to the operation. They may include nausea or vomiting but can also include problems related to the heart, lungs, kidneys, and stroke. If any of these are severe enough, there is a very small chance of dying.
Deep vein thrombosis and pulmonary embolus – these are blood clots in the legs that can travel up to the lungs. An assessment will be performed to see if you require stockings, intermittent calf compression boots, or medication to thin your blood in the post-operative period.
Infection: any operation has a small risk of infection so antibiotics are often given at the start of the operation to reduce this risk. Following a fusion, you may require several further doses to reduce infection risk.
Bleeding: there is bleeding with most operations. In larger procedures, a blood transfusion may be required. In those cases, we often collect the blood as it comes out, filter it, and give it back to you (cell salvage) to reduce the chance of you requiring a formal blood transfusion.
General Spinal Operation Risks
Nerve injury – operating around the nerves, there is a small risk of injury to the nerves; this can vary from short term minor problems through to long-lasting weakness or severe nerve pain (this is rare). The nerves to the bladder and bowels may also be affected which can result in incontinence or loss of normal function.
Spinal cord injury – for operations involving the cervical spine or thoracic spine, the spinal cord passes the operative area and there is a small risk of injury to it. In the worst scenario, this could result in paralysis affecting all levels below the operative site, and affect bladder and bowel function.
Dural tear / Durotomy / Spinal fluid leak – the nerves are surrounded by the dura, which is the membrane containing the spinal fluid. During the operation, it may be stuck onto the surrounding structures and can tear. The surgeon can often repair it at the time but you may need to lie flat on bed-rest for 24-48hrs to allow it to heal. If you still have problems after that time, you may require another operation to help close any further spinal fluid leakage.
Epidural haematoma – blood can collect around the nerves in the post-operative period. Occasionally, this can press on the nerves and stop them working. This requires an urgent operation to remove the haematoma and decompress the nerves.
Major blood vessel injury – there is a very small risk of major blood vessel injury during posterior spinal operations which can be life-threatening. The risk is slightly higher when performing anterior or lateral / oblique procedures.
Eyesight problems – there have been a few reports of eyesight problems after long spinal operations. Although exceptionally rare, in the worst scenario, this could result in blindness.
Continuing, recurrent, or worse pain – Some people find that their leg pain can disappear immediately following surgery whilst others find it takes a few weeks to settle down. Unfortunately, some people do continue to get some pain after surgery although most people find it is better than pre-operatively. Others find the pain has improved but they are left with numbness down the leg or arm as a result of the nerve being pressed on prior to the operation.
Pain can sometimes come back in the future; this may be related to a recurrent disc prolapse, scar tissue, or further degenerative changes pressing on the nerve.
In a very small number of people, their pain may be worse.
Recurrent disc prolapse – following microdiscectomy, there is a small chance that some more disc material can come out and press on the nerve again. This often happens in the first few months after surgery so it may be advisable to avoid heavy lifting, deep bending, and awkward twisting for a period of time following surgery. If it does happen, it often settles within 4-6 weeks.
Specific risks for fusion surgery and deformity correction
Metalwork / implant malposition – Xrays are used during the operation to confirm placement of screws and cages. However, there is a small chance they may not be in the perfect position. In the uncommon situation where they happen to be pressing on a nerve, a further operation may be required to reposition the screw.
Pseudarthrosis and implant failure – bone graft is placed around the fusion site. This often takes at least 6-9 months to fuse up. This can be assessed on Xrays taken in clinic following the operation. If it does not fuse up, it is called a pseudarthrosis and the metalwork can loosen or break over time – this may or may not require intervention depending on your symptoms.
Adjacent level disease – when a level of the spine is fused, there is potentially more stress on the levels adjacent to it. This can lead to degenerative changes occurring sooner than they otherwise might have. This does not necessarily require intervention, depending on your symptoms.
Specific risks for anterior cervical spinal surgery
Injury to trachea (wind pipe) / oesophagus (food pipe) / blood vessels (supplying brain, thyroid, and other structures).
Swallowing difficulties – these often resolve fairly quickly after surgery but may be prolonged in a small number of people.
Recurrent laryngeal nerve palsy – this is a rare complication but can result in a hoarse voice and difficulty singing or shouting. It often improves quickly after surgery but may be long-lasting and require further input from the Ear, Nose, and Throat team.
Sympathetic nerve injury – this is a very rare complication and may result in a drooping eyelid. It may recover shortly after the operation but could be long-lasting.