Lumbar facet joint block: computed tomography guided technique compared with fluoroscopy guided technique using the posterior approach: a comparative study

ABSTRACT

Facet joint is a main source of chronic low back pain with a prevalence of 16.7%. Clinical examination and imaging are insufficient to diagnose facet joint syndrome [30% accuracy and 45% false positives]. Facet joint block is the gold standard in diagnosis of facet joint syndrome. It can also relieve pain for up to 6 months. It can be done under computed tomography [CT] or fluoroscopy. To identify which imaging modality is more suitable to guide the procedure of lumbar facet joint block, fluoroscopy or CT. Thirty four lumbar facet joints represented by 12 patients were injected in the radiology department, Suez Canal University Hospital, Ismailia, Egypt from 1/2005 to 1/2006. All cases were suspected of having facet joint syndrome based on clinical or radiological data. After clinical examination and reviewing lumbar images to identify target facets, every patient underwent facet joint block under either CT or fluoroscopy. Fluoroscopy was more successful in guiding the injections [success rate 77.7% compared with 31.25% in CT guidance]. It is also faster [6.6 minutes per joint compared with 10.9 minutes for CT guidance]. Less number of trials were required [1.7 trial compared with 6.6 trials with CT guidance]. Fluoroscopy exposed the patients and the radiologist to much irradiation [21.3 rad compared to 0.3 rad in CT guidance]. Decreased bone density and laminectomy impair fluoroscopy guidance. CT guidance is difficult in patients with marked arthropathy and coronally oriented joints [8 trials compared with 5.6 for normally appearing joints]. Fluoroscopy should be the primary choice for guiding lumbar facet joint block. It is more successful and faster. Its disadvantages include much irradiation to patients and radiologists, and difficulty in patients with laminectomy and decreased bone density. CT can then be used to guide the block