Most spondylolytic defects and cases of Spondylolisthesis are congenital. The prevalence of Spondylolisthesis in the general population is about 5% and is about equal in men and women. Spondylolysis and Spondylolisthesis most frequently involve L5, although L4 can also be affected and, rarely, more proximal levels.
Type I. Dysplastic: This type results from congenital abnormalities of the upper sacral facets or inferior facets of the fifth lumbar vertebra that allow slipping of L5 on S1. There is no pars interarticularis defect in this type. The sacrum is not strong enough to withstand the weight and stress. Thus, the pars and inferior facets of L5 are deformed. If the pars elongates, it is impossible to differentiate it by x-ray from the isthmic (type II b) Spondylolisthesis. If the pars separates, it becomes impossible to differentiate it by x-ray from the isthmic lytic (type II a) Spondylolisthesis. This type is also associated with sacral and neural arch deficiencies. It has a familial tendency.
It is thought that athletic activities that require repeated hyperextension and rotation or repetitive combined flexion-extension predisposes athletes to develop pars defects. There are multiple types of spondylolisthesis and the exact cause is unknown.Isthmic and degenerative are the two types that are most common in adults. The three other types include traumatic, pathological, and dysplastic. The case study patient was a Lytic spondylolisthesis, which is always due to a fatigue fracture and is commonly seen in patients less than 50 years old.Overall, as the vertebral body slips forward there is narrowing of the spinal canal and intervertebral foramen which results in stenosis. As stenosis occurs the typical presentation changes from one of back pain to one that includes radicular symptoms. The typical clinical presentation of a spondylolisthesis is pain generally localized in the lumbar paraspinals, gluteals, and posterior aspects of the thighs. The symptoms usually increase with standing or walking. As the slippage progresses there is typically more irritation of the nerve root and the hamstrings become tight. This may be of benefit to a patient because of the hamstring insertion into the ischial tuberosities which would support a posterior pelvic tilt and subsequently decrease lumbar lordosis. Patients tend to walk in a more flexed position and develop increased hip flexor muscle tension. Flattening of the sacrum can be seen as the patient attempts to stop the slippage.Diagnosis usually occurs by radiographs and the slip can be graded by the Meyerding’s system. In this system a Grade I is up to 25% displacement, Grade II 50%, Grade III 75%, Grade IV 100%, and Grade V greater than 100% displacement.It has been found that only 10-15% of these patients go on to have spinal surgery and that most improve with nonoperative treatment. Typical nonoperative care includes rest, NSAIDS, ESIs, and a physical therapy program. Clinical significant improvements have been found with interventions that included lumbar flexion exercises and walking, but even more substantial improvement was found with the addition of manual therapy (joint mobilization and manual stretching) when performed to the lumbar spine and lower extremities.
Degenerative spondylolisthesis usually occurs in older women, most often at L4/5, but can occur at other levels. This type of slip is due to degeneration of the pair of facet joints between the two affected vertebrae. It is virtually never worse than grade 1.
Lytic spondylolisthesis usually occurs at L5/S1 and normally presents in the teenage years or 20s. The classical example is the so-called fast (cricket) bowler’s “stress fracture”. It occurs due to repetitive stresses in the lumbar spine but it often appears with no obvious history of repetitive trauma.