Spondylolisthesis is the displacement of the overlying vertebra in relation to the underlying one. The cause of the pathology is congenital anomalies, injuries, tumors, degenerative changes of the spine or spondylolysis. Spondylolisthesis is manifested by limited mobility of the affected part and pain in the lower back. With narrowing of the spinal canal and compression of nerve roots, neurological symptoms may be detected. The diagnosis is made on the basis of radiography, if necessary, CT and MRI are prescribed. Treatment is usually conservative, surgical interventions are performed if ineffective.
Spondylolisthesis is a disease in which one vertebra is displaced in relation to another. In the vast majority of cases, the lumbar spine is affected, while L4-L5 usually suffer, pathology at the L3-L4 level is less often detected. Spondylolisthesis affects people of all ages, including the most active and able-bodied category of the population (from 20 to 40 years). According to various data, from 2 to 6% of the population suffers from this disease.
There may be two forms of spondylolisthesis: more common anterolisthesis (the overlying vertebra shifts anteriorly) and less common retrolisthesis (the overlying vertebra shifts posteriorly). Spondylolisthesis can be isolated, but combinations with other diseases of the spine are more often observed: spondylolysis, spondylarthrosis, osteochondrosis, kyphosis, scoliosis, etc. Treatment of spondylolisthesis is carried out by vertebrologists or orthopedic traumatologists.
Taking into account the reasons in vertebrology, traumatology and orthopedics, there are five types of spondylolisthesis:
- Dysplastic spondylolisthesis. It occurs as a result of congenital malformations of the spine: non-hardening of the vertebral arch (spina bifida), hypoplasia of the vertebral arches, hypoplasia of transverse or articular processes, as well as abnormally high standing of the fifth lumbar vertebra. It usually appears in childhood or early adolescence and gradually progresses as the spine grows. With serious developmental disorders, it can be pronounced.
- Isthmic spondylolisthesis. It is caused by a defect in the vertebral arch (spondylolysis) due to a fatigue fracture caused by increased loads and repeated excessive extension of the lumbar spine. It is often detected in athletes (gymnasts, rowers, rugby players, etc.), but it can also be diagnosed in people who lead a low-activity lifestyle. It is detected in patients of all ages, while in children, as a rule, a mild degree is observed, in adults – no higher than average.
- Degenerative (involutive) spondylolisthesis. It occurs due to arthrotic changes in the joints of the vertebrae. The cause of osteoarthritis is degenerative changes in cartilage. This variant of spondylolisthesis is mainly diagnosed in patients over 65 years of age. It is more often found with an increase in lumbar lordosis and thoracic kyphosis.
- Traumatic spondylolisthesis. It is formed after damage to the interarticular part of the arch or fracture of the articular processes.
- Pathological spondylolisthesis. Occurs due to a bone defect caused by a tumor, Paget’s disease, arthrogryposis, etc.
Clinically, stable and unstable spondylolisthesis are distinguished. With stable spondylolisthesis, the relationship between the vertebrae remains constant regardless of the patient’s posture, with unstable – they change with a change in body position. There are two classifications based on the severity of radiological signs of spondylolisthesis. In the classification of Meyerding, compiled taking into account the degree of displacement of the superior vertebra in relation to the inferior, there are:
- 1 – the vertebra is displaced by no more than ¼.
- 2 – the vertebra is displaced by no more than ½.
- 3 – the vertebra is displaced by no more than ¾.
- 4 – the vertebra is displaced by more than ¾.
Kuehl and Junge additionally distinguish the 5th degree of displacement of the vertebra – complete displacement anteriorly (spondyloptosis). The classification of spondylolisthesis, compiled by Mitbreit, is based on an assessment of the degree of displacement of the vertebra by the angle between the vertical line and the line drawn through the centers of neighboring vertebrae. According to this classification, there are:
- 1 – an angle of 46-60 degrees.
- 2 is an angle of 61-75 degrees.
- 3 is an angle of 76-90 degrees.
- 4 is an angle of 91-105 degrees.
- 5 – an angle of 106 degrees or more.
Patients may complain of moderate or severe pain in the lower back, sacrum, coccyx and lower extremities. There is a relationship between the localization of pain and the age of the patient. Middle-aged patients often note lower back pain in combination with pain in the cervical and thoracic spine (due to overloads and incipient degenerative-dystrophic changes). Children with spondylolisthesis often complain of pain in the lower back and lower extremities.
During the external examination, a change in the position of the pelvis is revealed (depending on the degree of spondylolisthesis, both a forward tilt and a backward turn are possible), an increase in thoracic kyphosis and a deepening of lumbar lordosis. With pronounced spondylolisthesis, there may be a relative elongation of the limbs, shortening of the trunk, deepening of the dorsal furrow, hypotrophy of the gluteal muscles, asymmetry of the Michaelis rhombus, contracture of the muscles straightening the spine and the flexor muscles of the lower leg. Palpation determines the deepening above the spinous process of the upper (displaced) vertebra, pain during palpation of the spinous process and local pain in the affected area with axial load on the spine.
Some patients with spondylolisthesis have neurological symptoms due to narrowing of the spinal canal or compression of nerve roots. Patients note paresthesia (crawling goosebumps, feeling of heaviness in the legs) when standing and walking. There may be sensitivity disorders (hyperesthesia, hypesthesia, dysesthesia), muscle hypotrophy and paresis of the lower extremities, increased knee reflexes, loss or decrease of abdominal, achilles and anal reflexes and a positive Lasega symptom (pain and a feeling of tension on the posterior surface of the lower limb when trying to lift the leg in a supine position). In some patients with spondylolisthesis, horsetail syndrome is detected: urinary incontinence, perineal anesthesia, anesthesia and sluggish paresis of the lower extremities, as well as pronounced radicular pain in the perineum, buttocks, legs and sacrum.
The main method of instrumental diagnosis of spondylolisthesis is radiography of the spine. This study allows us to determine the degree of spondylolisthesis and identify concomitant pathology (congenital malformations, spondylolysis, spondylarthrosis, etc.). At the initial stages, functional X-ray examinations are carried out, since weakly expressed signs of spondylolisthesis may not be detected on standard radiographs. If necessary, a CT scan of the spine, X-ray contrast studies and MRI of the spine are prescribed. Patients are referred for consultation to a neurologist.
Initially, conservative methods of treatment are used. Patients are recommended to exclude physical exertion, especially those associated with bending and lifting weights, physiotherapy, massage and balneotherapy are prescribed, NSAIDs are used for inflammation and severe pain syndrome. With persistent pain syndrome, epidural cortisone injections are performed. Patients with isthmic spondylolisthesis are recommended to wear a corset that fixes the lumbar spine and prevents overextension.
Well-organized physical therapy classes are of great importance in spondylolisthesis of 1-2 degrees. Exercise therapy helps to strengthen the muscular corset and reduce the load on the spine, as well as reduce pathological lumbar lordosis, which is especially important in the treatment of patients who have spondylolisthesis combined with scoliosis. In addition, patients are taught special poses that help reduce muscle contractures and return the displaced vertebra to a physiological position.
Spinal surgery is indicated for children and adolescents with progressive spondylolisthesis of 2 or more degrees, for adults – with unstable spondylolisthesis that does not respond to conservative therapy. Progressive neurological disorders are also an indication for surgery. The purpose of the surgical intervention is to return the displaced vertebra to its normal position (if possible) and to fix the spine by performing an anterior fusion.
With narrowing of the spinal canal, impaired cerebrospinal fluid circulation, arachnoid cysts and gross changes in the membranes of the spinal cord, a laminectomy is performed with a revision of the spinal canal in combination with simultaneous or subsequent spinal fusion. In the postoperative period, staying in bed in a semi-bent position lying on your back for 2-4 months is indicated. Subsequently, during the year it is necessary to use a rigid corset.
Prognosis and prevention
The prognosis for spondylolisthesis is favorable in most cases. Prevention of this disease consists in early detection of malformations and subsequent dispensary observation. Adults are recommended to undergo lumbar spine x-ray before applying for a job related to lifting weights, and before starting some sports. The presence of congenital anomalies, spondylolysis, spondyloarthrosis and osteochondrosis is a contraindication for the above activities. In order to avoid deepening lumbar lordosis and reduce the likelihood of developing spondylolisthesis during pregnancy, women are advised to do special gymnastics, do not wear high-heeled shoes and use a bandage.