Low back pain is a common & complex problem affecting about 40% to 80% of general population in life time and point prevalence being 14 to 20% About one fourth of U.S. adults report low back pain in the past 3 months. And patterns of direct healthcare expenditures among individuals with back pain in the United States have reached $90.7 billion for the year 1998.
Before availability of diagnostic IPM procedures etiology remained unclear in most situations (85-90%) even with CT/MRI. In one prospective evaluation, consecutive adult patients with intractable low back pain (who had failed conservative therapy) of undetermined etiology (by medical history, physical examination, x-ray, CT, MRI, EMG/NCV) had pain from facet joint(s) in 24%, combined lumbar nerve root and facet Spinal Pain disease in 24%, combined facet(s) and sacroiliac joint(s) in 4%, lumbar nerve root irritation in 20%, internal disc disorder in 7%, sacroiliac joint in 6%, and sympathetic dystrophy in 2%. No cause was identified in 13% of patients. In another similar study, 40% of the patients were shown to have facet joint pain, 26% discogenic pain, 2% sacroiliac joint pain, 13% segmental dural/ nerve root pain and no cause was identified in 19% of the patients.
Thus diagnostic IPM procedures like facet joint block, provocative discography, epidurogram, selective nerve root block, SI joint block etc. can unmask diagnosis in most situations. Similarly therapeutic IPM procedures which include facet joint interventions encompassing intra-articular injections, medial branch blocks, and medial branch neurotomy; sacroiliac joint interventions, including sacroiliac joint blocks, and radiofrequency neurotomy; epidural injections including caudal epidural injections, interlaminar epidural injections, and transforaminal epidural injections; epidural adhesiolysis including percutaneous adhesiolysis, and spinal endoscopic adhesiolysis; intradiscal therapies including percutaneous micro-discectomy/ disc decompression, nucleolysis and implantable therapies, which include spinal cord stimulation and intrathecal drug administration systems give permanent/long-term relief.