Background

A few reports are available in the literature of fractures of fifth lumbar vertebra. However, to our knowledge there is no report concerning pathological fractures of the fifth lumbar vertebra.  It is the aim of this paper to report 10 patients had pathological fractures of the fifth lumbar vertebra.

Patients and methods

The patients were 6 males and 4 females with a mean age of 54.4 (range; 25-71) years. One patient had neurological impairment (Frankel grade D). Pain was assessed on Denis pain scale.

MRI pattern of the fracture was classified into: anterior wedging, central collapse, uniform collapse and posterior wedging.All patients was operated through a single posterior approach by curettage, biopsy and by transpedicular screw instrumentation.  The anterior defect was reconstructed by anterior bone grafting (5 patients)or limited spinal shortening (2 patients) or both (1 patient) and anterior reconstruction was not performed in 2 patients.

Results

Cause for pathological fractures was metastases in 5 patients; solitary myeloma in 2 patients and spinal infections in 3 patients with the causative microorganism in 2 patients was TB and staph aureus in the 3rdcase. The patient with pre-operative neurological deficit had neurological improvement o to grade E.  In the 7 patients with pathological fractures due to tumors, the pattern of collapse was central compression (3 patients), posterior wedging (3 patients) and uniform collapse (1 patient). For the 3 patients with pathological fractures due to infection, the pattern of collapse was uniform collapse (2 patients) and anterior wedging (1 patient). All patients got improvement of pain.  Mean follow up was 26.8 months.

Conclusion

Similar to pathological vertebral fractures at other spinal levels, central collapse of the vertebral body is highly suggestive of malignant compression fracture while anterior vertebral wedging is highly suggestive of a benign compression fracture. What seems peculiar to the pathological fractures of L5 is the very high incidence of posterior wedging pattern. Surgical treatment of L5 pathological fractures through a single posterior exposure is a relatively simple and safe operation. It gives good access sufficient to excise the lesion and reconstruct the spine