Lumbar arthrodesis

What is lumbar arthrodesis?

Lumbar arthrodesis is a surgery performed on the spine to fuse two or more vertebrae and limit movement between them. This surgery is advised to treat severe spinal pathologies or conditions that compromise the stability of the spine such as deformities, fractures, degenerative diseases or other ailments that cause instability and pain.

The lumbar spine, located in the lower back between the last thoracic vertebra and the sacrum, is composed of five lumbar vertebrae (L1-L2-L3-L4 and L5). This section of the spine provides support, stability and flexibility, allowing movements such as flexion, extension and rotation. It also protects the spinal cord and the nerves that branch out to the legs.

The lumbar vertebrae are the largest vertebrae in the spine and support the majority of the body’s weight.

What is lumbar spinal fusion?

Lumbar arthrodesis is a surgery that aims to permanently fuse two or more vertebrae in the lumbar region so that there is no movement between them. This is achieved by placing titanium alloy (or cobalt-chrome) screws and rods that stabilise the spine and allow the vertebrae to fuse, along with bone grafting.

Lumbar arthrodesis can be carried out through different procedures and approaches, the choice of one or the other will depend on the criteria of the medical team, taking into account the number of vertebrae to be treated, their position and degree of injury.

• Anterior lumbar interbody fusion (ALIF): the approach is from the anterior part of the abdomen.
• Anteroposterior lumbar arthrodesis: dual approach from the abdomen and back.
• Lateral approach fusion (XLIF): usually also performed with a posterior approach to ensure stabilisation of the spine.
• Posterior lumbar arthrodesis (TLIF): this is the most commonly used technique; the approach is through the back (lumbar area) and transpedicular screws and rods and, in some cases, intervertebral boxes are used to perform the fusion.

Through the incision point and avoiding injury to the surrounding tissues, prosthetic material (screws, plates, boxes and rods) is placed to achieve the fusion and the affected discs or bone fragments are removed and replaced with bone graft (from the patient, donor or synthetic bone) to reinforce the fusion.

In lumbar spinal fusion surgeries of a certain size and complexity, it is common to have the participation of a neurophysiologist to evaluate the function of the nervous system in real time and to minimise and avoid possible neurological injuries. This is done by means of intraoperative neurophysiological monitoring: the monitoring of potentials provides the surgeon with continuous information on the status and functionality of the nervous system.

In which cases/pathologies is it indicated?

The decision to perform lumbar arthrodesis is based on a thorough assessment of each individual case, taking into account the symptoms, the degree of involvement and the response to conservative treatment.

Lumbar arthrodesis may be indicated in the following cases:

• Spondylolisthesis: Spondylolisthesis is the displacement of one vertebra over the adjacent one. If symptoms are severe or if the condition does not respond to conservative treatments, lumbar arthrodesis may be an option to stabilise the spine and reduce pressure on the nerves.
• Lumbar canal stenosis: Spinal stenosis is a narrowing of the spinal canal that can compress nerve roots and cause pain and weakness in the legs. If conservative treatment is not effective, lumbar arthrodesis may be considered to relieve symptoms.
• Spondylolysis: Spondylolysis is a fracture in a specific part of a vertebra. If adequate healing is not achieved or if there is instability in the spine due to this condition, lumbar arthrodesis may be necessary to provide stability.
• Recurrent disc herniation: If a herniated disc recurs after conservative treatment or previous surgery, lumbar arthrodesis may be considered to stabilise the spine and relieve pain.
• Spinal deformity (scoliosis or kyphosis): this is the most common technique and, to date, with the best proven results for correcting deformity, especially adult deformity.
• Disc degeneration: lumbar arthrodesis may be recommended when there is significant wear of the intervertebral discs, which can cause chronic pain and functional limitations.
• Vertebral fractures: due to trauma or lumbar degenerative pathology.
• Vertebral tumours

How long does the surgery last?

Lumbar arthrodesis surgery is performed under general anaesthesia and can last between 2 and 6 hours, depending on the number of vertebrae to be fused and the complexity of the case.

What is the postoperative period like in hospital and at home?

After surgery, the patient must stay in hospital for a few days for pain control and recovery. In hospital, the patient will begin to walk around after 24 or 48 hours, depending on their condition and immediate postoperative evolution. During the following days of hospitalisation, the patient will carry out mobilisation exercises and will gradually increase their walking and ambulation autonomy with the help of physiotherapists to facilitate their return home.

During the first weeks after surgery, the patient should avoid heavy lifting and strenuous and impact activities.

What are the main risks?

The main risks associated with lumbar spinal fusion include infection, bleeding, nerve injury, chronic pain, pseudarthrosis (nonunion of the fused vertebrae), and anaesthesia-related complications.

What limitations will the patient have in the medium term?

After surgery, the patient may experience low back pain and stiffness for several weeks or months. The patient may also have limitations in their ability to perform strenuous physical activities, such as lifting heavy objects or participating in high-impact sports. It is important that the patient follows the recommendations of their surgeon and physiotherapist to ensure a successful recovery. It is important that the patient follows the recommendations of the surgeon and physiotherapist to ensure a successful recovery.