Image Based Question – 73101

What should be the most likely diagnosis of this 65 year old lady presents with backache and following radiograph of the spine shown in image:

A. Osteoporosis

B. Spondylolisthesis

C. Spondylolysis

D. Discitis

Correct Answer » B Explanation

Answer. B. Spondylolisthesis

• Spondylolisthesis is subluxation of lumbar vertebrae, usually occurring during adolescence.
• It usually results from a congenital defect in the pars interarticularis (spondylolysis).
• Spondylolisthesis is usually fixed (ie, permanent and limited in degree). It usually involves the L3-L4, L4-L5, or L5-S1 vertebrae.
• Spondylolisthesis often occurs in adolescents or young adults who are athletes and who have had only minimal trauma; the cause is a lumbar vertebra weakened by a congenital defect in the pars interarticularis (spondylolysis).
• This defect is easily fractured; separation of the fracture fragments causes the subluxation. Spondylolisthesis can also occur with minimal trauma in patients who are > 60 and have osteoarthritis.
• If mild to moderate (subluxation of = 50%), spondylolisthesis, particularly in the young, may cause little or no pain.
• Spondylolisthesis can predispose to later development of spinal stenosis.
• If due to major trauma, spondylolisthesis can cause spinal cord compression or other neurologic deficits; these deficits rarely occur.

[This x-ray shows stage 1 spondylolisthesis of L5 on S1. The black arrow shows the posterior border of L5, which subluxes anterior to S1. The red arrow points to the spondylolysis (congenital defect in the pars interarticularis).]