Sixth Lumbar Vertebra

After 6 weeks of persistent low back pain, an overweight 72-year-old woman sought medical evaluation. There was no history of trauma.

The patient had no genitourinary complaints; results of the neurologic assessment were normal. Her lifestyle was sedentary; gardening was her primary activity.

The differential diagnosis included chronic osteomyelitis, spondylolisthesis, osteoporotic pathologic fracture, and osseous neoplasm; radiographs ruled out these disorders. Despite the lack of radicular signs and symptoms, herniated nucleus pulposus (HNP) was considered because of the patient's age and the narrowed intervertebral disc spaces. HNP was ruled out by MRI.

Physical examination found no trigger points. The source of pain was localized strictly to muscular structures.

Thomas A. Keel, MS, OPA, of San Antonio, Tex, explains that no radiographs had been taken of this patient before this episode; thus, the adventitious finding of a sixth lumbar vertebra surprised both patient and practitioner.

The extra vertebra is a congenital variant that was not associated with the patient's soft tissue axial skeleton symptoms. However, L6 is another possible site for the development of osteoporosis, disc space degeneration, and spondylolysis or spondylolisthesis.

Physical therapy and NSAIDs were prescribed for the patient's low back pain. She was encouraged to lose weight and exercise regularly.