A 69-year-old female complained of intermittent right leg radicular pain in the past two years and which became worse with numbness in the recent four days. Moreover, the patient also had severe intermittent claudication, and the claudication distance was only about 20 meters. The decreased muscle force of the right quadriceps femoris and extensor hallucis longus and hypesthesia in the bilateral dorsal foot skin were found through physical examination. The Lasegue sign of the right leg was positive, and the bilateral Babinski signs were negative. The flexion and extension lateral lumbar radiographs showed segmental dynamic instability at L2-3 and L3-4 (Figure 1(a)). Sagittal computed tomography (CT) showed multilevel disc degeneration, severe osteophyte at L4-5, and L3 spondylolisthesis relative to upper and lower vertebra (Figure 1(b)). Magnetic resonance imaging (MRI) revealed serious central stenosis at L3-4 and lumbar disc herniation and right lateral recess stenosis at L4-5 (Figure 1(c)). White blood cell (WBC) count and blood chemistry, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) were all unremarkable during hospitalization.
Laminectomy of L4 and right-sided hemilaminectomy of L5 were performed to decompress the right L4, L5 nerve root, and dural sac. Discectomy and intervertebral fusion were done in L3-4 and L4-5 levels, and bilateral facet joint fusion of L2-3 was performed due to segmental dynamic instability of L2-3. L2 to L5 were fixed by rigid instruments (DePuy Synthes, West Chester, PA, USA). The right leg pain visual analogue scale (VAS) had decreased significantly the first day after surgery. Celecoxib was given to relieve low back pain. The patient was discharged home after she was able to walk independently without difficulties with a Boston brace (ten days after the surgery). The postoperative and one-month follow-up's lumbar radiographs showed no abnormal findings (Figure 2).
Two months after the surgery, however, the patient returned to our department with serious throbbing low back pain. The physical examination did not reveal any dysfunction of lumbar and sacral nerves. The surgical wound had healed completely. And there was a little percussion pain over the spinous process of upper instrumented vertebrae. The blood laboratory test was indicative of bacterial infection, WBC count 7.5*109/L, neutrophile granulocyte percentage (NEU) 87.9%, ESR 16 mm/h, CRP 87.25 mg/L, and procalcitonin (PCT) 0.049 mug/L. Although the location of the infection and pathogenic bacteria were unclear, the empirical antibiotic vancomycin was prescribed after vein blood culture. However, the blood culture did not show any bacteria growth a few days later. The spondylodiscitis signal of adjacent segment in lumbar MRI further confirmed our hypothesis of infection of the lumbar spine (Figure 3(b)).
The low back pain was relieved by vancomycin anti-infective therapy and celecoxib. After 5 weeks intravenous vancomycin anti-infective treatment, the patient was discharged home and we advised our patient to proceed with orally administered cefdinir. The blood laboratory tests were done periodically, and the main inflammatory index changing curves are shown in Figure 4.
Within 20 days after the last review, the patient presented again with exacerbation of throbbing low back pain. The blood laboratory test suggested that the spondylodiscitis in L1-2 was uncontrolled, WBC count 10.1*109/L, NEU percentage 89.9%, ESR 30 mm/h, CRP 38.40 mg/L, and PCT 0.047 mug/L. Vancomycin and cefoperazone were combined to cover both Gram-positive cocci and Gram-negative bacilli, and oral metronidazole was used to cover the anaerobe as well. Moreover, the radiographic images revealed serious spondylodiscitis and bony endplate destruction at the adjacent L1-2 segment (Figure 5).
The combined anti-infective therapy continued for a week, and the serious low back pain relieved quickly with blood inflammatory indexes dropping significantly. Single intravenous cefoperazone was used sustainably, and radiographic examinations were taken to observe the destructive extent of L1-2 segmental spondylodiscitis. The patient needed to keep strictly on her bed to avoid infective space collapse. After five-week continuous anti-infective therapy, the main blood inflammatory indexes dropped to the normal level (Figure 6), with slight residual symptom. However, the spondylodiscitis and bony endplate destruction at the L1-2 space had little changes (Figure 7).
The patient then underwent posterior intervertebral debridement and posterior superior iliac crest autograft implant at the L1-2 space; the initial pedicle screws in L2 were taken out for high temperature sterilization and reimplanted. And the upper instrumented level was extended to L1 (Figures 8(a) and 8(b)). The wound drainage was pulled out after continuous negative bacterial culture of drainage liquid. The patient had satisfactory symptom relief and significant inflammatory indexes decreased (Figure 6). The debrided tissues from L1-2 did not show tumor, tuberculosis, and fungal infection through pathologic examination, and the bacterial culture did not show any bacteria growth. The patient was able to walk independently with the Boston brace (one week after revision surgery). The intravenous cefoperazone was used sustainably for four weeks after the second surgery, and then the patient was discharged.
The patient came back to the out-patient department for review every two weeks. The inflammatory indexes almost dropped to normal (Figure 6). The six-week follow-up's CT scan showed that the destructive space was closed to fusion (Figure 8(c)). The patient did not complain of obvious symptoms any more.