Low Back Pain Dr. Proper

Low Back Pain Jacqueline Proper M.D. Oh, My Aching Back…. • Incidence 5-10% / year • Lifetime incidence 50-80% • Substantial economic impact – Diagnosis and Rx – Lost productivity/worker absenteeism • ? Excessive imaging and surgery What is the Cause? • Deconditioning, degenerative disease most common ~ 80% • Spinal structures involved as pain generators: – – – – – Ligaments Facet joints Paravertebral musculature and fascia Spinal nerve roots Annulus fibrosis What Is the Cause? • Spinal stenosis: narrowing of central spinal canal or its lateral recesses • Disk herniation: protrusion of nucleus pulposis through fissures in the annulus fibrosus What is the Cause? • 85% cannot be given precise pathoanatomic diagnosis – Nonspecific Dx frequent: sprain, strain, degenerative disease • Association between imaging and symptoms is weak Table 2 Table 2. Representative Results of Magnetic Resonance Imaging Studies in Asymptomatic Adults. From: Deyo: N Engl J Med, Volume 344(5).February 1, 2001.363-370 Epidemiology • Men and women equally affected • Onset usually between age 30-50 • Most common cause of work-related disability in people under age 45 • Most expensive cause of work related disability Diagnostic Evaluation • Careful History and Physical Exam – Details of pain: location, quality, radiation, relieving and aggravating factors, previous treatment • Questionairre • Considerations: – Systemic disease? – Neurologic compromise? – Social or psychological distress as amplifying factors? • Imaging not always necessary Diagnostic Evaluation • Neurologic symptoms: – Pain of sciatica/pseudoclaudication – Associated numbness or paresthesia • Prolonged symptoms – Failure of previous Rx – depression – somatization – Pursuit of disability/involvement in litigation g." TABLE III Disability and Work Status at the Time of the Four-Year Follow-up From: ATLAS: J Bone Joint Surg Am, Volume 82-A(1).January 2000.415 Diagnostic Evaluation • Imaging: early use discouraged – Overdiagnosis, dependence on medical care – Failure to improve in 4-6 weeks – clinical suggestion of infection, cancer, persistent neuro deficit • Diagnostic blocks often used to determine origin/proper management Diagnostic Blocks Selective Spinal Nerve Root • • • • • Multilevel disease/ post surgical patient ? contribution of nerve root inflammation Needle placed in intervertebral foramen  1.o cc local anesthetic plus steroid Degree of pain relief indicative of positive result Diagnostic Blocks Facet Joint • Facet joint: true synovial joint connecting adjacent vertebrae posteriorly • Pathology: arthritis, inflammation, segmental instability • Back pain without radicular sx – – – – Hip/buttock pain Low back stiffness Paraspinal tenderness Pain with hyperextension Diagnostic Blocks Facet Joint • Intra-articular technique – Needle placed in joint /confirmation – 1 cc L.A.  steroid-minimize volume – 2% incidence of exacerbation of pain • Successful block does not require complete pain relief Diagnostic Blocks Facet Joint • Medial branch block – Medial branch of primary dorsal ramus of spinal nerve: sensory innervation to facet joint – Dual innervation – lower pole of facet at nerve level and upper pole of facet joint below – Beam at 35-40 degree angle to sagittal plane, eye of Scottie dog – 1 cc L.A./ >50% reduction in pain/ no sensory changes Diagnostic Blocks Myofascial Trigger Points • Significant portion of LBP • Trigger point diagnostic criteria – Taut palpable band with tender point – Altered sensation in distribution of referred pain from myofascial trigger point – May have restricted range of motion • Local twitch response / EMG evidence of spontaneous electrical activity in tender point Diagnostic Blocks Myofascial Trigger Points • Quadratus Lumborum – Muscles parallel to lumbar spine and vertically connected from 12th rib to post 1/3 iliac crest – Flexes spine ipsilaterally – Pain referred over iliac crest or SI joint down to midbuttock or to abdomen or groin Diagnostic Blocks Myofascial Trigger Points • Piriformis – Muscle origin at sacrum with insertion on greater trochanter – Sciatic nerve variation – P.E.: Forced internal rotation/resisted external rotation of thigh – Pain radiates to buttock, SIJ to lateral hip – Referred pain: posterior leg to sole of foot Diagnostic Blocks Myofascial Trigger Points • Gluteus medius-thigh abduction – Upper portion of ilium to PSIS, inserts on greater trochanter – Pain along iliac crest and sacrum – Radiation to midbuttock and into posterior superior thigh Diagnostic Blocks Myofascial Trigger Points • Injection of trigger point – Insertion of needle may elicit twitch – 3-5 cc L.A. with 2-4 mg/cc of depo-medrol – Pain relief indicative of successful injection Diagnostic Blocks Sacroiliac Joint Injection • Pain in distribution - medial superior buttock, lateral buttock, superior lateral thigh • Provocative tests: FABER’s, POSH, REAB – Done in combination has 100% specificity and 77% sensitivity • Injection is diagnostic gold standard Diagnostic Blocks Discography • Disc abnormalities – 50% of cases of LBP • Nerve supply in outer part of annulus fibrosis. Degenerative disc -more extensive nociceptive innervation • Discogenic pain – deep dull ache/low back/ minimal radiation to beyond gluteal region/ pain worsens with axial loading Diagnostic Blocks Discography • Injection of nucleus pulposus with saline or contrast media • Concordant pain – indication for IDET or surgical fusion if multilevel disease Therapy • Acute LBP, nonspecific origin – NSAIDs on regular schedule – Delay PT, manipulation – Return to “normal” activities – Bedrest not helpful – Back exercises in late phase to prevent recurrence/ treat chronic pain Table 2. Primary Outcomes among the Patients in the Bed-Rest and Control Groups. From: Vroomen: N Engl J Med, Volume 340(6).February 11, 1999.418-423 Table 3. Indications for Surgical Referral among Patients with Low Back Pain. From: Deyo: N Engl J Med, Volume 344(5).February 1, 2001.363370