The spine is made up of vertebrae connected to each other by ligaments and intervertebral discs. All of these elements endow the spine with properties that make it both mobile but also stabile when static. The stability and mobility of the spine are essential for everyday life.
The stabilizers can be subdivided into two functional groups: active (muscles) and passive (ligaments, intervertebral discs, and joint articulation surfaces).
The evolutionary transition into an upright posture and walking on two legs has created new challenges for this system. Many of the responses to these challenges are compromises, leading to an ever more delicate balance between mobility and stability. This is why spine ailments are incredibly common in humans.
Spondylolisthesis is a condition where a vertebra slips forward over the one below it. The spine becomes unstable, which leads to a series of unwanted structural and biomechanical changes. The intervertebral disc gets burdened from abnormal directions. The capsules of the intervertebral joints (facet joints) get greatly stretched or even “dislocated” in some cases, and the neuroforamina (either of a pair of spaces each side of a vertebra that allows nerves to pass from the spinal cord to other parts of the body) reduce in diameter. All these structural changes lead to aberrations from the normal biomechanics of the spine. This is a factor for developing early degenerative changes both around the discs and the facet joints. Another consequence is neurological damage caused by pressing onto the nerve roots in the intervertebral spaces (foramina), where the nerves leave the spinal column.
The most frequently affected area is the bottom level of the lumbar spine, between the 5th lumbar and 1st sacral vertebrae. The reason for this is the structure of the intervertebral joint, which enables the highest degree of mobility in the lumbar region, but also the highest probability of destabilization.
There are many causes for developing spondylolisthesis, e.g. congenital malformations, acute trauma to the spine, degenerative joint diseases, osteoporosis, and tumors.
Spondylolisthesis can be classified into grades based on the degree of severity. More advanced stages require surgical treatment.
One of the symptoms is different degrees of pain in the spine, which can spread along the area innervated by the affected nerve. Loss of sensation, muscle strength, and deep reflexes are also a possible development. Other very characteristic symptoms are an increase in the lumbar curve known as hyperlordosis, as well an unusually increased range of motion in the waist.
It is of utmost importance that patients diagnosed with spondylolisthesis be well informed about the proper conservative treatment for their condition. This includes developing a highly functional abdominal wall and paravertebral musculature. Everyday habits need to be revised and adapted to the proper position and motion of the spine.