What is Lumbar Spinal Fusion?
The surgical technique of combining two or more vertebrae is known as spinal fusion. Back pain due to abnormal motion of the vertebrae is treated by this procedure. Fusion of the vertebrae involves the insertion of secondary bone tissue obtained either through autograft (tissues from the same patient) or allograft (tissues from another person) to enhance the natural osteoblastic process of the body.
Lumbar region of the spine is more prone to spine fusion, compared to the other regions such as cervical and thoracic parts of the spine. Due to slight normal motion in the thoracic spine, rarely any problem is seen. Endorsing lumbar spinal fusion is contentious. Usually, spinal fusion is recommended in patients with neurological problems or severe pain that have not responded to conservative treatment.
Spinal fusion can be performed through different angles depending upon the specific advantages of each and the choice of your surgeon. In posterolateral fusion, bone grafts are placed between the transverse processes present in the back of the spine. In spinal fusion screws and wires are attached through the pedicles of the vertebrae along with a metal rod to fix the affected vertebrae.
Spinal fusion may involve interbody fusion where bone graft is placed in the space present between the two vertebrae. Other techniques may also be employed for spinal fusion that involves the entire removal of the intervertebral disc between the affected vertebrae. A specially designed device made either from plastic or titanium may be placed between the vertebrae. This helps in maintaining spine alignment and the normal height of the disc. In some cases, both types of fusion can be employed, known as 360-degree fusion.
It has been noted that fusion rates are seen to be higher in interbody fusion. Based on the different approaches, interbody fusion can be classified in the following types:
- Anterior lumbar interbody fusion (ALIF): This procedure is performed through an anterior abdominal incision.
- Posterior lumbar interbody fusion (PLIF): The disc is accessed through a posterior incision over the back.
- Transforaminal lumbar interbody fusion (TLIF): The disc is accessed through a posterior incision on one side of the spine
The fusion process is followed by fixation that involves fitting of metallic screws, rods, plates, or cages to stabilize the vertebrae and accelerate bone fusion. After surgery, 6-12 months are required for the complete fusion. For better healing of fusion, smoking is prohibited, heavy activities are restricted and certain medications are prescribed. In rare cases where fusion is incomplete, revision surgery may be employed.
What are the Indications for Lumbar Spinal Fusion?
Various spinal conditions may be treated through lumbar spinal fusion such as degenerative disc disease (DDD), spinal stenosis, herniated disc, spinal tumor, kyphosis, vertebral fracture, and scoliosis.
Lumbar spinal fusion may treat symptoms such as back pain while sitting, bending or twisting, bowing of the back, chronic neck pain, claudication in the legs, abnormal curving of the spine, uneven shoulders, uneven hips, and other spine-related conditions.