Mooney and Robertson asked whether the lumbar facet joint can independently generate low back pain, sciatica, and neurologic signs typically attributed to disk herniation. Using fluoroscopically confirmed facet joint injections in 20 experimental subjects and a 100-patient clinical series, they evaluated facet injection as both a diagnostic and therapeutic tool.
When a patient presents with low back pain, leg radiation, reduced SLR, and even depressed reflexes, the reflex of diagnosing disk herniation is strong — but this paper shows every one of those findings can arise from the facet joint alone.
The practical implication: in a patient without specific dermatomal sensory loss, specific motor weakness, severely diminished SLR, or crossed SLR, facet pathology belongs high on the differential. A diagnostic facet block under fluoroscopy is both a test and a treatment. Relief confirms the pain generator, and about half of carefully selected patients gain meaningful benefit at 6 months.
Because each facet joint receives innervation from at least two spinal levels and the pain distribution is non-specific, injecting the lower three facet joints on the symptomatic side is standard. You cannot localize the culprit level by pain pattern alone.
This 1976 paper is the founding document for the entire field of facet-mediated pain and medial branch blocks. The anatomy it described. The medial branch descending through a notch at the transverse process base. Remains the anatomic target for medial branch blocks and radiofrequency ablation used today.
Mooney and Robertson asked whether the lumbar facet joint can independently generate low back pain, sciatica, and neurologic signs typically attributed to disk herniation. Using fluoroscopically confirmed facet joint injections in 20 experimental subjects and a 100-patient clinical series, they evaluated facet injection as both a diagnostic and therapeutic tool.
When a patient presents with low back pain, leg radiation, reduced SLR, and even depressed reflexes, the reflex of diagnosing disk herniation is strong — but this paper shows every one of those findings can arise from the facet joint alone.
The practical implication: in a patient without specific dermatomal sensory loss, specific motor weakness, severely diminished SLR, or crossed SLR, facet pathology belongs high on the differential. A diagnostic facet block under fluoroscopy is both a test and a treatment. Relief confirms the pain generator, and about half of carefully selected patients gain meaningful benefit at 6 months.
Because each facet joint receives innervation from at least two spinal levels and the pain distribution is non-specific, injecting the lower three facet joints on the symptomatic side is standard. You cannot localize the culprit level by pain pattern alone.
This 1976 paper is the founding document for the entire field of facet-mediated pain and medial branch blocks. The anatomy it described. The medial branch descending through a notch at the transverse process base. Remains the anatomic target for medial branch blocks and radiofrequency ablation used today.