A 63-year-old male was transferred from a local clinic, complaining of radiating pain to both lower extremities lasting for one week. The tender points were found on the midline of back and both paravertebral muscles, but body temperature was normal. The range of motion of his spine was severely limited, and there was a decrease of the straight leg raising tests (60/60). The motor powers of the extensor hallucis longus were decreased bilaterally and ankle jerks were absent bilaterally. He denied the history of acupuncture or local injections in the back.
Initial investigations revealed that the white blood cell count was 9,300/mL, the erythrocyte sedimentation rate was 118 mm/hr and C-reactive protein was 12.5 mg/dL. Serum GOT/GPT levels were 59/87 IU/L, but the sonogram of the liver was normal. The electromyography and nerve conduction study revealed radiculopathies of L5 and S1, bilaterally. Plain radiographs of the L-spine showed no specific abnormality. MRI revealed two space-occupying lesions, which were located on both sides of the anterior epidural space, and a signal change of the dural sac at the level of L4 and L5 (). Computed tomography (CT) axial scans revealed the same space-occupying lesion, adhesion and thickening of the roots of L4 and L5, and showed irregular widening and bony erosion of the facet joints of L4-5 (). Technetium-99 m bone scan demonstrated increased uptake at the L4 and L5 levels ().
Axial T2-weighted MRI reveals two space-occupying lesions, which are located on both sides of the anterior epidural space (arrows), and a signal change of the dural sac at the level of L4 and L5.
Axial CT reveals a space-occupying lesion on anterior epidural space, adhesion and thickening of the roots of L4 and L5, and irregular widening and bony erosion of the facet joints of L4-5 (arrows).
Technetium-99 m bone scan shows increased uptake of radioisotopes on the bodies and posterior arches of L4 and L5 (arrows).
On the 4th day of admission, he had chills with temperatures to 38.9
with increasing back and radicular pain. The white blood cell count was 11,200/mL, erythrocyte sedimentation rate (ESR) was 123 mm/hr and C-reactive protein (CRP) was 14.1 mg/dL. We decided on surgical decompression after parenteral antibiotics (first generation cephalosporin & aminoglycoside) for 2 days.
Under a general endotracheal anesthesia, a total laminectomy and bilateral medial facetectomies of L4 and partial laminectomies of L3 and L5 were performed. In the surgical field, the L4-5 facet joints were destroyed and the drained pus from the facet joints was located on both sides of the anterior epidural space. A severe adhesion between the dura and the annulus fibrosis, and a thickening and adhesion of the L4 and L5 roots were also noted. A histological examination from frozen biopsy revealed an inflammation. The drainage of the pus and the removal of the inflamed granulation tissues and surrounding fibrous tissues were performed. In fear of incomplete removal of the infected tissues and for local control of the infection, we decided to use antibiotic-cement beads. Vancomycin 4 gm and bone cement 40 gm were mixed, and 7 rows of beads were inserted on the posterior aspect of L3 to S1 (). We planned the fusion with or without instrumentation after removal of the antibiotic-cement beads two weeks later. The radiating pain was immediately relieved after the operation. First generation cephalosporin and aminoglycoside were administered intravenously for two weeks. The blood and intraoperative pus cultures demonstrated methycillin-sensitive Staphylococcus aureus.
Postoperative plain radiograph shows posterior decompression and antibiotic-bone cement beads in posterior aspect of the spine.
During the second surgery, some pus that was admixed with chocolate colored liquid material was noted, so we abandoned the use of instrumentation. A posterolateral fusion with autogenous iliac bone at the level of L3 to L5 was performed. Second generation cephalosporin and quinolon were then administered intravenously for 3 weeks. Oral quinolon was then prescribed for four weeks until the ESR was normal. The patient was on bed rest postoperative for 3 weeks, and then was ambulated with thoracolumbosacral orthosis for 3 months. At three-months after surgery, solid fusion was achieved (). And at 2 years follow-up, the patient returned to normal physical activity without low back pain.
Three months postoperative plain radiograph shows the posterolateral fusion is solid.