Lets understand Spondylolisthesis in a simple way…
There are 5 lumbar vertebrae, that are stacked one on top of other in a way that their boundaries circumferentially exactly match each other. Spondylolisthesis is a condition where an upper level vertebrae slips over the vertebrae below it, making its boundary cross the lower vertebra. In simple words the vertebrae are not stable on each other.
This condition is little more difficult to handle than the two conditions discussed previously, slipped disc and spinal stenosis because in these two previous conditions the problem is only compression of neurological structures namely the nerve roots and dural sac. In Spondylolisthesis, we have to deal with two problems:
- Instability of spine, that is abnormal movement of one vertebrae on other while we move or bend forward or backwards. This abnormal movement may cause significant back pain to the patient.
- Compression of the nerve root or dural sac that cause radiating pain down your legs, heaviness or burning sensation in your legs and claudication symptoms due to compression of the dural sac.
To deal with these two conditions simultaneously, we need to decompress the neural structures (nerve root and dural sac) and at the same time stabilise the two vertebrae together by means of cage, screws and rods. Once the two vertebrae are stable they start to behave as one and the abnormal movements of the vertebrae stop happening.
How do you know you have Spondylolisthesis?
The following are the symptoms and signs of Spondylolisthesis:
- Back pain that is more severe than the leg pain. Pain in the back increases on bending forward and backwards.
- Radicular pain in one or both the legs that starts from low back and goes down to the back of buttocks, thighs and legs that may go upto foot.
- This may be associated with numbness and heaviness in legs, burning sensation in the leg or heaviness in the legs.
- On examination by your spine surgeon, if Spondylolisthesis is severe, he may notice a dip in your low back, change in posture and gait may also be observed.
How is Spondylolisthesis confirmed?
A special X-ray called dynamic x-ray of Lumbar spine reveals instability of the spine. Based on the X-Ray, grade of slip is evaluated.
What is role of MRI in Spondylolisthesis?
MRI is useful to assess the severity of nerve root or dural sac compression. This helps in surgical planning on the extent of decompression required, side of the patient that needs to be decompressed and the technique of endoscopy that needs to be used, trans-foraminal or inter-laminar.
Do all Spondylolisthesis need surgery?
No, all Spondylolisthesis don’t need surgery. Surgery is required or not, depends on whether the listhesis is stable or unstable, the grade of listhesis and the presence of nerve symptoms. Grade 1 stable Spondylolisthesis with only mild back pain and no neurological symptoms can be managed with physiotherapy and medications.
When is surgery required for Spondylolisthesis?
Following situations require surgical intervention in Spondylolisthesis:
- Significant back pain limiting the mobility during day to day activities.
- Change in posture and gait due to Spondylolisthesis
- Radiating pain in one or both legs
- Weakness in legs or any joint of the lower limb like knee ,ankle or toes.
- Inability to hold urine or faces (Bowel or bladder incontinence)
- These symptoms should corroborate with the Xray and MRI findings of the patient
What are surgical options available for Spondylolisthesis?
Two concerns need to be addressed in Spondylolisthesis,
- Back pain that arise because of spine instability. This requires stabilising the spine by means of cage, screws and rods.
- Neurological symptoms that occur due to nerve compression. This requires decompression of neural structures by removing the tissues causing compression.
There are three ways to address these two concerns, by means of endoscopic spine surgery, microscopic spine surgery and open spine surgery.
1. Endoscopic decompression and percutaneous screw and rod fixation: In endoscopic decompression, the ligamentum flavum, disc and facet is targeted directly without damaging the surrounding tissues with help of specialised camera system called endoscopes. It is least invasive form of decompression. After decompression is done, very small incisions are given to put screws and rods in the spine, thereby fixing the spine and overcoming instability. There are minimum incisions, few stitches, minimum blood loss, early rehabilitation and quick recovery. Collateral tissue damage is minimum amongst all the techniques of decompression and fixation therefore long term pain relief is best.
2. Microscopic decompression and percutaneous screw and rod fixation: The offending structure is targeted with help of tubular retractors and microscope. After decompression is achieved, small incisions are given to put screws and rods percutaneously. This is also a less invasive form of surgery but collateral tissue damage is more than endoscopic technique.
3. Open decompression and screw and rod fixation: This is the conventional and original form of surgery. Here all the structures superficial to the problem causing structure are damaged to gain access and there is more of collateral tissue damage. These tissues include the muscles, supraspinous and interspinous ligaments, lamina etc. that are important to spine stability. Also open surgery involves bigger incision, more blood loss, prolonged rehabilitation and longer recovery time.
What surgery do we do in Spondylolisthesis?
We perform a fully endoscopic decompression of the neural structures using trans-foraminal or inter-laminar technique whichever is suitable for the patient.
Stability of spine is achieved with percutaneous screw and rod stabilisation of spine.
We strongly avoid open surgery of Spondylolisthesis to enable early recovery of our patients.
