[6] Spondylolisthesis is classified as one of the six major etiologies: degenerative, traumatic, dysplastic, isthmic, pathologic, or post-surgical.

A slip or fracture of the intravertebral joint is usually acquired between the ages of 6 and 16 years, but remains unnoticed until adulthood.

[13] It is divided into three subtypes:[16] Classification by degree of the slippage, as measured as percentage of the width of the vertebral body:[17] Grade I spondylolisthesis accounts for approximately 75% of all cases.

[7] If the spondylolisthesis is mobile or increases its position with movements such as bending forwards (flexion) or backwards (extension), it's called 'unstable'.

[24] A patient with high grade spondylolisthesis may present with a posterior pelvic tilt, causing a loss in the normal contour of the buttocks.

[24] An antalgic gait, rounded back and decreased hip extension can result from severe pain.

[27] In adults with non-specific low back pain, strong evidence suggests medical imaging should not be done within the first six weeks.

[29] It is also suggested to avoid advanced imaging, such as CT or MRI, for adults without neurological symptoms or "red flags" in the patient's history.

[32] Children and adolescents with persistent low back pain may require earlier imaging and should be seen by physician.

[22] Anteroposterior (front-back) and lateral (side) images are used to allow the physician to view the spine at multiple angles.

[33][34] In evaluating for spondylolithesis, plain radiographs provide information on the positioning and structural integrity of the spine.

[35] Preference is due to effectiveness, lack of radiation exposure, and ability to evaluate for soft tissue abnormalities and spinal canal involvement.

[35][36] MRI is limited in its ability to evaluate fractures in great detail, compared to other advanced imaging modalities.

[41] Conservative treatment consists primarily of physical therapy, medication, intermittent bracing, aerobic exercise, pharmacological intervention, and epidural steroid injections.

[47] Three indications for potential surgical treatment are as follows: persistent or recurrent back pain or neurologic pain with a persistent reduction of quality of life despite a reasonable trial of conservative (non-operative) management, new or worsening bladder or bowel symptoms, or a new or worsening neurological deficit.

[49] A retrolisthesis is a posterior displacement of one vertebral body with respect to the subjacent vertebra to a degree less than a luxation (dislocation).

[50] He reported a bony prominence anterior to the sacrum that obstructed the vagina of a small number of patients.