Repairing the posterior wall of sacral canal in Tarlov cyst operation procedure

Large sacral cysts lead to chronic erosion of the sacrum. Dr. Xuesheng Zheng’s team has always prioritized the protection of the sacral bone and the repair of the posterior wall of the sacral canal during surgical procedures. This is essential to prevent the protrusion of the sacral canal’s contents. For a deeper understanding, please refer to our previous article titled:

“Minimally Invasive Surgical Concept for Sacral Canal Cysts: Maximizing Bone Protection.”

“This comprehensive guide covers all aspects of minimally invasive surgery for sacral cysts, including detailed explanations with pictures and text. It is highly recommended for those interested in this topic.”

“A case study on minimally invasive surgery for multiple giant sacral cysts.”

“A case of giant Tarlov cyst by Dr. Zheng’s team with a mere 4.5cm incision.”

Today, we will delve into the significance of repairing the posterior wall of the sacral canal from the perspective of the sacral vertebrae’s weight-bearing capacity and stability.

Consider a patient weighing 60 kilograms. The weight above the lumbar spine, approximately 40 kilograms, is transmitted through the lumbar spine to the sacral vertebrae (primarily sacral 1-2), then through the sacroiliac joint to the pelvis, and finally through the hip joint to the lower limbs.

Contrary to the misconception that the sacrum does not bear weight, it acts as the load-bearing foundation of the spine. As such, it is relatively thick and sturdy. However, sacral cysts pose a significant threat, akin to dismantling the load-bearing walls of a building.

The sacral erosion caused by these cysts can vary in severity. Some patients may lose the ability to stand, while others may still be able to walk. However, even in the latter case, the sacrum is barely supporting the body, akin to a piece of paper maintaining its shape to support a larger weight.

This fragile balance can be easily disrupted if the sacral cyst further develops and breaches the anterior or posterior wall of the sacral canal. Even patients with long-standing giant sacral cysts without severe symptoms may experience rapid deterioration after a fall, leading to irreversible damage. This is because the sacral vertebrae may already be severely thinned, and minor trauma can cause fractures that may not be visible on CT scans but significantly compromise the sacrum’s structural integrity.

Therefore, for patients with sacral canal cysts causing significant bone erosion, repairing the posterior wall of the sacral canal during surgery is crucial for maintaining spinal stability and weight-bearing capacity.

In summary:

Sacral canal cyst surgery should prioritize the use of small bone windows to minimize bone structure disruption.
Accurate location of leakage is essential to avoid the need for expanding the bone window.
The bone defect in the posterior wall of the sacral canal caused by the lesion itself should be fully utilized, with slight expansion to form a small bone window.
After successful closure, titanium plates should be used to repair the bone defects in the posterior wall of the sacral canal, restoring the sacral canal’s basic shape and maintaining the stability and weight-bearing capacity of the sacral vertebrae. The importance of posterior wall repair increases with the size of the sacral cyst.

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