With its humanistic thinking and new concept, the non-fusion technology of the spine has turned a new page in the surgical treatment of spinal disorders, and its application has a bright future. In developed countries, the concept of “non-fusion” has been widely accepted, but in China, it has just started. Non-fusion technology of the spine has already been carried out in our hospital.
France is one of the first countries in the world to develop non-fusion technology in the spine. The Petitia-Salpetitia Hospital, affiliated with the University of Paris VI, is the largest public hospital in Europe with a history of nearly 400 years. Its orthopedic department enjoys a high status in France and the whole Europe and has treated celebrities such as Princess Diana and Cristiano Ronaldo. It performs nearly 100 spinal non-fusion surgeries every year and has accumulated a wealth of clinical experience. The non-fusion techniques of the spine are represented by anterior artificial disc replacement techniques, such as artificial cervical disc replacement and artificial lumbar disc replacement, and also include posterior non-fusion techniques, such as artificial ligaments and interspinous spine bracing devices. The advent of non-fusion techniques in the spine has given spine surgeons new options to maintain spinal mobility and stability, rebuild the biomechanical properties of the disc, and prevent and reduce the acceleration of degeneration in adjacent segments. The focus of treatment is not only on the operated segment itself, but also on the adjacent segments, making it more important and relevant for young and middle-aged patients.
What is the non-fusion technique of the spine and what is the interspinous support system or WALLIS?
Degenerative disc changes are degenerative over time, leading to dysfunction and pain in the spine.
Like all other joints, the discs degenerate over time, and this degeneration also includes aging, which is commonly referred to as “degenerative disc disease. Degeneration of the discs is a natural process, especially in people in their 40s and 50s, but it does not generally result in systemic pain.
However, a number of other factors can accelerate the degenerative process of the disc. The various muscles that surround the spine are commonly referred to as the trunk muscles, such as the abdominal and dorsal extensors, which protect the anatomy of the spine by providing stability under muscle tone. For those who are not physically active on a regular basis, their muscle tone is somewhat reduced so that the spine is less well protected and the disc tissue is more prone to degeneration.
The stability of the spine depends on the muscle tone, the health of each vertebra and the specific condition of the intervertebral tissues, including the discs. Dysfunction of the muscles and discs will lead to instability of the spine.
The view from biomechanics is that ……
…… This instability of the spine results from abnormal activity and reduced stiffness of individual or multiple segments.
Spinal instability can cause not only chronic pain, but also sharp pain and sensory abnormalities in a particular position.
Whether or not this chronic degenerative disease causes the disc to become more susceptible to injury, that disc is at risk for additional accidental injury, as exemplified by disc herniations that occur during inadvertent movements, accidents in daily life, and sports activities. Often in such cases painful symptoms in the lower back or legs (i.e., lower back pain or leg pain) often occur with the onset of disc herniation or spinal stenosis.
Herniated discs
When the disc is subjected to excessive pressure, such as from abnormal activity, excessive physical work, or if the disc has been damaged, ……
…… A portion of the disc may be extruded, resulting in a herniated disc. The extruded portion can compress one or more nerve roots in its vicinity and cause pain
The spinal cord begins at the top of the spine and extends to the second lumbar vertebra. Below the second lumbar vertebra, several nerve roots form the “cauda equina”. In clinical practice, doctors often refer to cases of compression of the cauda equina as “cauda equina syndrome.
Symptoms of a herniated disc
The typical symptoms of a herniated disc can be divided into two general categories.
Lower back pain and radicular pain
-Lower back pain caused by degeneration of the disc
-Radicular pain (i.e., leg pain) is caused by herniated discs
The most common types of radicular pain include sciatica along the course of the sciatic nerve and femoral neuralgia along the course of the femoral nerve.
In patients with sciatica, the pain travels from the buttock along the back of the thigh to the back of the calf, and typically radiates all the way to the tips of the toes.
In femoral neuralgia, the pain travels down the anterior thigh to the anterior calf.
Typically, sciatica occurs correspondingly on the posterior aspect of the lower extremity, while femoral neuralgia occurs on the anterior aspect of the lower extremity.
When the compression is acute and severe, the pain can sometimes be accompanied by partial loss of sensation or even muscle paralysis of the lower extremity.
Spinal stenosis
The vertebrae form a channel that protects the spinal cord by overlapping each other (down to the level of the L1-L2 disc) and extending to the nerve roots or “cauda equina” (below the level of the L1-L2 disc). This channel is also known as the “spinal canal”.
The diameter of the spinal canal is usually about 17 mm.
In patients with spinal stenosis, the diameter of the spinal canal is not large enough to accommodate the spinal cord or cauda equina.
In patients with spinal stenosis, the diameter of the spinal canal is usually small, usually less than 10 mm in diameter.
Many factors can cause the spinal canal to narrow, and over time, the ligaments and bone around the spinal canal gradually thicken, thus causing compression of the nerve roots.
In addition, a number of other factors can also cause spinal stenosis. For example, children who undergo intense physical training during their growth spurt may prematurely stop developing and not continue to enlarge. These children will maintain this condition into adulthood, which is often referred to as “developmental spinal stenosis”.
Symptoms of spinal stenosis
Patients gradually develop difficulty walking and shortened walking distances (neurogenic claudication), or radicular pain (such as sciatica and femoral neuralgia) during physical work, which is often temporarily relieved by squatting and leaning forward.
In the course of lumbar degeneration, the above mentioned phenomena (spinal instability, disc herniation, and spinal stenosis) often occur simultaneously.
For example, spinal instability and disc herniation often occur simultaneously: the nucleus pulposus of the disc is partially squeezed out and reduces the height of the disc, which becomes lax like a flat tire and subsequently causes or aggravates the spinal instability condition. Spinal instability with a herniated disc causes lower back pain along with lower extremity pain often due to the herniated disc.
In addition, herniated discs may also progress to spinal stenosis over time.
Dynamic stabilization of the lumbar interspinous process with internal fixation implants
The lumbar interspinous dynamic stabilization implant consists of an interspinous pad, two straps, two latches and two titanium rings.
During the procedure, the interspinous pad is placed between the two spinous processes of the diseased segment and two latches are used to secure the straps to the interspinous pad. Once the latches are placed in the correct position, the two straps are tightened around the adjacent spinous processes and the two rings are secured to the straps (Figure 1).
The lumbar interspinous dynamic stabilization implant can be considered a powerful addition to the surgical treatment of some patients with disc dysfunction.
In patients with herniated discs, physicians usually begin by removing the herniated portion of the disc that is compressing the nerve root in order to relieve pain in the lower extremity.
This is followed by the placement of a lumbar interspinous dynamic stabilization implant to reduce or eliminate the patient’s lower back pain caused by spinal instability.
In patients with spinal stenosis, the spinal canal is enlarged to provide adequate space for the nerve tissue, and the corresponding spinal segment is then fixed with a lumbar interspinous dynamic stabilization implant to slow the degeneration process of the fixed segment and prevent the recurrence of spinal stenosis.