Table 1.

Inclusion and exclusion criteria

Inclusion criteria

Age 18 years or older

Lower back pain without radicular symptoms

Symptoms subjectively relieved by 90% or greater with fluoroscopically guided diagnostic injections

Willingness to self-pay for the injection therapy

Symptoms of 6 months or longer duration

Exclusion criteria

Bowel or bladder dysfunction related to LBP

Current vertebral/pelvic girdle fracture

Failure to demonstrate significant relief with diagnostic injection

Rheumatic disease

Active or recurrent carcinoma

History of prostatic carcinoma

Objective neurological deficit/radicular signs (myotome weakness, dermatome sensory loss, loss of deep tendon reflex, positive SLRa/PKBb/Slump test

Pregnancy

Notes:

^aSLR was considered positive if less than 40° with greatest symptoms in the lower extremity;

^bPKB considered positive if L3 or L4 dermatomal symptoms reproduced, with the worst symptoms reported in the lower extremity. Slump test considered positive if LE symptoms were reproduced with neck flexion during slump sitting/knee extension/ankle dorsiflexion, and LE was relieved to any degree with neck extension.

Abbreviations: LBP, low back pain; SLR, straight leg raise; PKB, prone knee-bend; LE, lower extremity.