Spinal Surgery

Conditions treated

  • Sciatica: leg pain due to a disc prolapse or bony stenosis from the lumbar spine resulting in pressure parts of the sciatic nerve
  • Claudication: unilateral or bilateral leg pains following a period of standing or walking short distances that may be associated with numbness, burning or paraesthesia (pins and needles) in the feet. Due to pressure on the cauda-equina (spinal nerves) from central canal stenosis in the lumbar spine.
  • Myelopathy: stiffness and twitching of the arms and legs due to pressure on the spinal cord at the cervical or thoracic area. May be due to disc prolapses, canal stenoses or tumour compression. Progressive symptoms of numbness and paraesthesia (pins and needles) in the hands and feet, and clumsiness (dropping things) in the hands are a key feature.
  • Radiculopathy: a term used to describe nerve pain due to pressure in the spine regardless of the location within the spine. Hence sciatica is also “lumbar radiculopathy”, and pressure in the neck is “cervical radiculopathy”.
  • Back Pain: only a small proportion of back pain can be treated surgically. Back pain may result from neuro-muscular dysfunction, degenerative lumbar discs, facet arthropathy and instability. In general, surgery for back pain is only indicated if there is a focal area clearly responsible for the pain. Surgical treatment for back will involve a spinal fusion.

Lumbar microdiscectomy

A microdiscectomy is performed for sciatica or lumbar radiculopathy due to a lumbar disc prolapse. In general a period of conservative management consisting of oral pain killers, physiotherapy and hydrotherapy and/or an epidural steroid injection is the treatment of choice for sciatica. If symptoms persist and are not tolerable after 6-8 weeks of conservative management, a microdiscectomy may be considered.

This is performed under a general anaesthetic. A small 2-2.5cm cut is made in the lower spine directly over the disc prolapse. Using the operative microscope for magnification and illumination, the compressed nerve and disc prolapse are identified and the offending disc fragment removed. The rest of the disc is left in-situ to prevent delayed back pain.

Surgery of this manner has an 80-90% chance of success in well chosen surgical cases. The in-hospital stay following a micro-discectomy ranges from 1 to 2 days. Some microdiscectomies are performed on a day-stay basis.

Risks of a lumbar microdiscectomy

Rare but major risks ( less than 0.5%; case dependent)

  • Nerve injury resulting in weakness, numbness, paralysis, bowel or bladder dysfunction, sexual dysfunction

More common and treatable risks (5-10%)

  • Bleeding
  • Infection
  • CSF leak
  • Recurrent disc prolapse
  • Delayed instability
  • Other medical complications (respiratory, cardiovascular, DVT/PE etc)

Lumbar microlaminectomy

A microlaminectomy is performed for neurogenic claudication due to lumbar canal stenosis. In general a period of conservative management consisting of oral pain killers, physiotherapy and hydrotherapy and/or an epidural steroid injection is the treatment of choice for sciatica. If symptoms persist and are not tolerable after 6-8 weeks of conservative management, a microlaminectomy may be considered.

This is performed under a general anaesthesia. For microlaminectomies up to 3 spinal levels, a 2.5 to 3cm skin incision will be made over the appropriate levels. Using the operative microscope for magnification and illumination, the lower lumbar nerve roots (cauda equina) are decompressed by drilling off the bony compression and removing the offending thickened ligamentum allowing restoration of the normal dimensions of the central canal. Both ipsilateral and contralateral nerve roots are visualised and completely freed up in this manner.

Surgery of this manner has an 80-90% chance of improving claudication (leg) symptoms. This surgery is not targeting back pain. The in-hospital stay following a microlaminectomy ranges from 1 to 3 days. For elderly or deconditioned patients undergoing this surgery, a short period of in-hospital rehabilitation may be arranged for them after their stay in the acute hospital.

Risks of a lumbar microlaminectomy

Rare but major risks (less than 1%; case dependent)

  • Nerve injury resulting in weakness, numbness, paralysis, bowel or bladder dysfunction, sexual dysfunction
  • Death under anaesthesia

More common and treatable risks (5-10%)

  • Bleeding
  • Infection
  • CSF leak
  • Delayed instability
  • Other medical complications (respiratory, cardiovascular, DVT/PE etc)

Minimally Invasive Lumbar Fusions

A lumbar fusion may be performed for degenerative (wear and tear), traumatic or neoplastic conditions. The basis of a lumbar fusion is the realignment of the spine and prevention of movement at a certain spine segment, thus attempting to achieve improvements in back pain, mobility and quality of life. A lumbar fusion may be performed in conjunction with a microlaminectomy, and may be performed over several spinal levels. In certain cases of severe spinal deformities, this may involve a staged operation over two sittings.

Lumbar fusions involve the substantial removal of the intervertebral disc and placement of an interbody spacer (cage made of reinforced PEEK) prefilled with bone substitute. This is supplemented by the placement of percutaneous pedicle screws through numerous small stab incisions in the back. The long-term goal of surgery is to allow bony growth between the vertebrae, thus preventing movement at the operated spinal level and relieving symptoms of discogenic or facet associated back pain.

Intra-operative neuro-monitoring is used in all cases of minimally invasive spinal fusions to maximise safety and prevent the rare risks of inadvertent neural injury. Intra-operative neuro-navigation may also be used for minimally invasive spinal fusions to maximise safety and prevent the rare risks of inadvertent neural injury.

There are three main options in minimally invasive lumbar fusions.

1) Trans-foraminal Lumbar Interbody Fusion (TLIF – MIS)

spine-TLIF

This is performed under a general anaesthetic. A 2.5 to 3cm skin incision is made about 4cm off the midline of the lower lumbar spine over the appropriate spinal level. The surgical approach utilises the natural planes of the spinal muscles and bluntly splits the muscle fibres rather than cutting them from one side only. Using tubular retractors and the operative microscope, the entire facet joint is removed and the disc approached in this manner. A complete discectomy is performed and an interbody cage placed at an angle across the disc. This interbody fusion is supplemented with percutaneous pedicle screws placed bilaterally through the same incision on the side ipsilateral to the TLIF, and small stab incisions on the contralateral side.

Risks of a TLIF

Rare but major risks (less than1%; case dependent)

  • Nerve injury resulting in weakness, numbness, paralysis, bowel or bladder dysfunction, sexual dysfunction

More common and treatable risks (5-10%)

  • Bleeding
  • Infection
  • CSF leak
  • Instrumentation failure, migration, malpositioning – occasionally requiring repeat surgery to reposition
  • Pseudo-arthrosis: failure of interbody fusion resulting in micro-movements and recurrent back pain
  • Adjacent segment disease: successful fusion at one level may in time accelerate degeneration at a spinal level immediately adjacent to the fused level thus resulting in recurrent symptoms
  • Other medical complications (respiratory, cardiovascular, DVT/PE etc)

2) eXtreme Lateral Interbody Fusion (XLIF)

spine-XLIF

This is performed under a general anaesthetic. A 2.5 to 3cm skin incision is made on the side with the spinal approach made through the side trunk muscles rather than the back muscles. These trunk muscles are bluntly split and entry into a fat-filled space called the retro-peritoneal space is achieved with minimal approach trauma. The psoas muscle lies on the sides of the lumbar spine and it is through this muscle that the intervertebral discs are reached. Under direct vision, a complete discectomy is performed and a large interbody cage placed across the entire width of the disc. This interbody fusion is supplemented with percutaneous pedicle screws placed bilaterally through small stab incisions on the back. This approach is not appropriate for all levels of the spine, particularly the L5/S1 level.

Risks of an XLIF

Rare but major risks (less than1%; case dependent)

  • Nerve injury resulting in weakness, numbness, paralysis, bowel or bladder dysfunction, sexual dysfunction
  • Bowel damage resulting in peritonitis
  • Large vessel injury (the inferior vena cava [large draining vein] and aorta [large feeding artery] sit immediately in front of the lumbar spine and are at small risk of injury)

More common and treatable risks (5-10%)

  • Bleeding
  • Infection
  • CSF leak
  • Thigh/hip pain: damage to the psoas muscle and the lumbar plexus nerves may result in weakness, numbness and a burning sensation over the front of the thigh. This is usually temporary however may take 6-8 weeks to improve.
  • Instrumentation failure, migration, malpositioning – occasionally requiring repeat surgery to reposition
  • Pseudo-arthrosis: failure of interbody fusion resulting in micro-movements and recurrent back pain
  • Adjacent segment disease: successful fusion at one level may in time accelerate degeneration at a spinal level immediately adjacent to the fused level thus resulting in recurrent symptoms
  • Other medical complications (respiratory, cardiovascular, DVT/PE etc)

3) Anterior Lumbar Interbody Fusion (ALIF)

This is performed under a general anaesthetic. A transverse 3 to 4cm skin incision is made low down in the midline of the lower abdominal wall. A retroperitoneal approach is taken to the lower lumber spine and exposure of the relevant discs is made with gentle protection of adjacent important vascular structures. Under direct vision, a complete discectomy is performed and a large interbody cage placed into the disc space. This interbody fusion may then be supplemented with an internal plate or by percutaneous pedicle screws placed bilaterally through small stab incisions on the back.