Posterior Fusion

What is Posterior Fusion? 

"Posterior fusion" is a term commonly used in spinal surgery. It's a surgical technique to join and stabilise two or more vertebrae in the spine, typically to reduce pain, restore stability, correct deformities, or protect the spinal cord and nerves.

This procedure is performed through the back (posterior) of the patient, hence the name. The surgeon places bone or bone-like material between the vertebrae and uses screws and rods to hold the vertebrae together to heal into one solid unit. This can be achieved through several techniques, like posterolateral fusion or transforaminal lumbar interbody fusion (TLIF).

Who is Suitable for Posterior Fusion?

Candidates for posterior fusion typically include those with conditions such as:

• Degenerative disc disease: When the discs between the vertebrae wear down, they can cause severe pain and instability. Fusion can help stabilise the spine and reduce or eliminate pain. However, anterior/lateral fusion is a better option for these patients.
• Scoliosis: This curvature of the spine can sometimes be corrected or prevented from worsening with a fusion procedure.
• Spinal stenosis: Fusion can be used to maintain spinal stability after a laminectomy procedure to relieve spinal stenosis.
• Spondylolisthesis: This condition, in which one vertebra slips forward onto the vertebra below it, can be treated with fusion.
• Fractured vertebra: A vertebral fracture that causes instability in the spine can be treated with fusion.
• Tumours or infections: If a tumour or infection has damaged the vertebrae, fusion can help restore stability.

Posterior fusion is a major surgery generally considered when non-surgical treatments have failed to relieve symptoms. The decision to undergo such surgery should always be made in close consultation with a qualified spinal surgeon.

Benefits of Posterior Fusion

• Pain Relief: Posterior fusion is often performed to reduce or eliminate pain caused by abnormal vertebrae motion or spine degeneration.
• Restored Stability: The procedure helps to stabilise the spine, which can be crucial following injury, infection, or due to degenerative conditions.
• Deformity Correction: Posterior fusion can correct spinal deformities like scoliosis or kyphosis.
• Enhanced Quality of Life: The procedure can significantly improve patient's quality of life by allowing them to return to activities without discomfort or reduced pain.

Types of Posterior Fusion

• Posterolateral Fusion (PLF): In this procedure, the bone graft is placed in the space between the transverse processes in the back of the spine. These vertebrae are held together with metal hardware until the graft fuses with the spine.
• Posterior Lumbar Interbody Fusion (PLIF): The surgeon removes the disc between two vertebrae and inserts bone into the space. This is usually done together with a posterolateral fusion.
• Transforaminal Lumbar Interbody Fusion (TLIF): Similar to PLIF, the approach to removing the disc and placing the bone graft is slightly different, allowing for less disruption of the normal tissues.

Alternative Options to Posterior Fusion

Alternatives may include both non-surgical and surgical options.

• Non-surgical Alternatives: These might include physical therapy, pain management with medications, chiropractic care, epidural injections, or other conservative treatment options.
• Surgical Alternatives: Depending on the specific condition, other surgical procedures might be considered, like decompression without fusion, disc replacement surgery, or minimally invasive spine surgery techniques such as Anterior or Lateral Lumbar Interbody Fusion (ALIF/LLIF).

Preparation for Posterior Fusion

• Medical Examination: Your surgeon will typically conduct a thorough medical examination, including reviewing your medical history and possibly ordering spine imaging studies.
• Medication Review: Inform your surgeon about any medications you take, including over-the-counter and dietary supplements. Before surgery, you may be asked to stop taking certain medications, such as blood thinners.
• Lifestyle Changes: Quitting smoking, maintaining a healthy diet, and getting regular exercise can help your body cope with surgery and improve your healing and recovery.
• Pre-surgery Testing: You may undergo blood tests, heart tests, and other preoperative procedures to ensure you're fit for surgery.
• Fasting: You'll likely need to fast (not eat or drink anything) for a certain period before surgery.
• Pre-surgical Physiotherapy: Some surgeons recommend a course of physiotherapy to strengthen the back muscles and improve recovery outcomes.
• Prepare for Recovery: Make sure your home is ready for your return post-surgery. You may need to arrange for assistance with daily activities during your recovery.

Posterior Fusion Procedure

• Anaesthesia: You will be given general anaesthesia, so you'll be unconscious during the procedure.
• Indwelling Catheter (IDC): A bladder tube will be placed to allow emptying your bladder before and during surgery. This will be removed the first day after the operation.
• Positioning: Your surgeon and the theatre team will position you on the surgical table face-down. 
• Incision: The surgeon will make an incision in your back over the vertebrae to be fused.
• Preparation: The posterior spine will be exposed, stripping the muscles off the bones, joints and ligaments of the posterior spine. 
• Screw and rod insertion: Your surgeon will identify landmarks and navigate screw insertion. Then place a rod into the screws to hold the position of the vertebrae and stabilise them while the bone graft heals.
• Bone Preparation: Decompression, burring and osteotomies will be performed as required to allow nerve decompression, deformity correction and bone fusion preparation. 
•  Fusion: The surgeon will prepare the bone graft (either from another part of your body or a donor's bone) or use a bone graft substitute, which they will place between the vertebrae. Closure: The surgeon will close the incision, usually over a drain.

Posterior Fusion Recovery Plan

• Hospital Stay: You will typically stay in the hospital for a few days up to a week after the surgery. The exact duration will depend on your condition and recovery.
• Pain Management: You may experience some pain and discomfort after the surgery, which can be managed with medications prescribed by your doctor.
• Physiotherapy: A physical therapist may work with you to help you regain strength and movement in your spine.
• Follow-up Appointments: You'll have follow-up appointments with your surgeon to monitor your progress and to ensure the fusion is healing properly.
• Recovery Time: Full recovery and fusion can take several months, and you will continue to improve for 1-2 years. Following your doctor's instructions for activities and limitations during this time is crucial to ensure the best possible outcome.
• Lifestyle Changes: Your doctor may suggest making certain lifestyle changes, such as maintaining a healthy weight and avoiding tobacco use, to help the fusion heal and improve your overall spine health.

Posterior Fusion Prognosis

In general, most patients experience a significant reduction in pain and improved quality of life. However, it's important to note that spinal fusion is a major surgery, and full recovery and fusion can take up to a year or more.

Posterior Fusion Risks

As with any surgery, there are potential risks associated with posterior fusion:

• Infection: Any surgical procedure carries the risk of infection. Antibiotics are typically given to minimise this risk.
• Bleeding: There is a risk of bleeding during and after surgery.
• Pain at Graft Site: If the bone graft is taken from the patient's own body, the site of the graft may be painful after surgery.
• Nerve Damage: There is a risk of damage to the spinal nerves during surgery, which can cause weakness, pain, or loss of sensation.
• Nonunion: This is when the vertebrae do not fuse as planned. It may require additional surgery.
• Hardware Failure: In some cases, the metal screws, plates, or rods used to stabilise the spine may move or break.
• Adjacent Segment Disease: Fusion can place added stress on the vertebrae above and below the fused portion, leading to further problems in the future.

What if Posterior Fusion is Delayed?

The consequences of delaying a posterior fusion surgery largely depend on the condition being treated. In some cases, delaying surgery may allow the condition to worsen, which could result in increased pain, further damage or degeneration, and possibly even permanent nerve damage. 

However, in other cases, non-surgical treatments may effectively manage the condition, and surgery can be safely delayed. It's crucial to consult with a qualified spinal surgeon to understand the potential risks and benefits of delaying surgery in each case.