1	Management of Lumbar Discogenic Pain D. Scott Kreiner, MD
2	Discogenic Back Pain Low back pain is the second most common reason that patients seek medical care More health care dollars are spent on back pain than any other condition IDD is the most common cause of low back pain, 40% of cases 3-6 million patients in US with chronic back pain Other causes include more severe disc injuries, posterior element pain, spinal stenosis, instability, fracture, etc
3	Lumbar Spine Five vertebral bodies Sacrum Five intervertebral discs Five lumbar nerve roots exit through the intervertebral foramen Five sacral nerve roots exit through the sacral foramen
4	Intervertebral Disc Nucleus pulposus Anulus fibrosis Vertebral end-plates
5	Nucleus Pulposus Semifluid mass with consistency similar to toothpaste Contains: Water Collagen Glycosaminoglycans Proteoglycans Enzymes
6	Anulus fibrosis 10-20 sheets (average 17) of collagen fibers called lamellae Lamellae are arranged in concentric rings surrounding the nucleus Lamellae are thicker in the anterior and lateral portions, posteriorly they are finer and more tightly packed Fibers of the lamallae are oriented parallel to one another and at an angle of about 65° from the vertical Direction of inclination of fibers alternates between each lamellae
7	Vertebral End-plates Layer of cartilage 0.6-1mm thick Covers the area on the vertebral body encircled by the ring apophysis Made of hyaline cartilage (near vertebral body) and fibrocartilage (near anulus) Deficient subchondral bone over about 10% of the vertebral end-plate allows nutrients from the marrow to diffuse into the nucleus
8	Innervation Outer 1/3 of anulus and PLL innervated by sinuvertebral nerves Anterior disc has some sensory input through sympathetic trunk Posterior spinal elements carry nociception through medial branch nerves
9	Dermatomes May be described as numbness, an “ache”, or less commonly paresthesias Dermatomes suggestive but not absolute
10	Myotomes T12, L1, L2, L3 Iliopsoas L2, L3, L4 Quadriceps Hip adductor group L4 Tibialis anterior Knee Jerk reflex L5 Extensor hallucis longus Gluteus medius Extensor digitorum longus & brevis S1 Peroneus longus & brevis Gastrocnemius-Soleus Gluteus maximus Ankle Jerk reflex
11	Radiculopathy Weakest point of the disc is the paracentral location or the posterolateral corner Disc protrusion in the paracentral location affects the descending nerve root at this level, usually not the exiting nerve root
12	Contained Disc Injuries
13	Non-contained Disc Injuries
14	Internal Disc Disruption 40% prevelance¹ Constant deep aching pain aggravated by any movement that mechanically stresses the disc No neurological deficits CT scans and myelography frequently normal Diagnostic criteria: Disc stimulation must reproduce the patients pain, adjacent discs non-painful Post-discography CT scan demonstrates at least a grade 3 anular fissure MRI may show a HIZ on T2 images in the posterior anulus
15	MRI – Internal Disc Disruption +/- desiccation +/- protrusion HIZ usually correlates with pain and anular tear¹
16	Granulation (Neural) Ingrowth
17	Protrusions Very common Nuclear material protrudes through some (but not all) of the anular fibers May or may not produce pain Not likely to spontaneously resolve May cause radicular pain and on occasion radiculopathy MRI is sufficient for diagnosis but will not tell if is causing pain
18	Extrusions Nuclear material has extruded through entire anulus, may or may not extend through posterior longitudinal ligament More likely to cause radiculopathy Usually occurs in the posterolateral corner Usually affects nerve descending behind the disc (i.e. L5 nerve root for L4-5 disc) Natural course is resolution May require surgery if weakness profound, does not improve or if incontinence develops
19	Sequested Fragment A piece of nuclear fragment separates from the rest of the extruded disc Usually displaces inferiorly May or may not be symptomatic (depends on location) Spontaneous resolution unpredictable
20	Diagnosis History Examination Imaging Electrodiagnostic Studies Provacative Discography
21	Complaints (Historic Features) Most common injury involves twisting/bending to pick-up something with an outstretched arm Pain in low back which commonly radiates into the gluteal area Pain increases with prolonged sitting, standing, walking Sitting intolerance Pain increases with motions that stress the disc (bending, lifting, twisting, etc.) Pain increases with coughing, sneezing, etc (result of increased intradiscal pressure) Pain below knee more common of a disc protrusion/extrusion than IDD Paresthesias common if dorsal root ganglia compressed Cramping/ache in myotomal muscles common with protrusion/extrusion
22	Physical Examination History of sciatica has a sensitivity of 98% and a specificity of 88% for predicting a herniated lumbar disc¹ SLR has a sensitivity of >90% for detecting disc herniation though the specificity is low (~15%) Lesague sign also predictive Weakness, sensory changes and decreased reflex are diagnostic of radiculopathy though not of its cause Sciatic notch tenderness +/- PSIS tenderness
23	Electrodiagnostic Studies Sensitivity is very low in patient’s with lumbar radicular pain; about 77% sensitive if radiculopathy present¹ Few indications: Exclusion of more distal nerve damage Verification of subjective muscle weakness in patients presenting pain inhibition or lack of cooperation Recurrent disc operation if difficult surgery is expected A patient’s radicular pain cannot be explained by neurophysiological testing Electrophysiological evaluation does not directly evaluate neurologic mechanisms associated with pain generation Can not accurately determine the precise spinal nerve level
24	Radiographs Shows bones only (not discs) No real role in diagnosing discogenic pain or radiculopathy in young patients Helpful in older patients where cause of radiculopathy more likely to be a result of degenerative foraminal stenosis Generally recommended only if history is atypical (i.e. unexplained weight loss, fever or chills, intense pain at rest, pain worse at night) or if fracture is a concern
25	CT Scan Preferred method for bony evaluation of spine May diagnose disc pathology though sensitivity very low compared with MRI Helpful in fractures or other bony abnormalities, 3D reconstruction sometimes useful Role in disc pathology limited to post-discography scanning or post myelography scan
26	MRI
27	MRI Order urgently if Cauda Equina Syndrome red-flag condition exists If no red-flag: Refrain from imaging on first visit, especially if early in course; wait until symptoms have persisted for ~6-7 wks Attempt conservative management prior to MRI Single level radicular weakness is not a clear indication for MRI if early Need MRI if surgery or possibly epidurals considered
28	MRI
29	Provacative Discography Only way to determine if a disc is causing pain Need “control” levels Pressures helpful Not a first line diagnostic study Is painful Risks minimal if precautions taken Controversial
30	Provacative Discography
31	Post-discography CT Scan Helps identify location of injury Helps identify extent of injury Allows for the best anatomic evaluation of the nuclear-anular junction
32	Treatment Options NSAIDs COX-II Inhibitors Oral Steroids Muscle Relaxants Narcotics TENs Physical Therapy Epidural Steroid Injections Thermal Annuloplasty Percutaneous disc decompression Discectomy Fusion
33	NSAIDs Helpful in reducing acute and sub-acute pain May have therapeutic effect on decreasing epidural inflammatory response COX-II inhibitors equally as effective as non-selective NSAIDs, safety profile better Should be first line agent
34	Oral Steroids Can help decrease epidural inflammation Reserve for use in patients with severe pain Systemic effects greater than for epidural steroids Know safety profile
35	Muscle Relaxants Gaba Agonists Baclofen (lioresal) Alpha₂ Agonists Zanaflex (tizanidine) SR Calcium Channel Blockers Dantrium (dantrolene) CNS depressants Soma (carisoprodol) Robaxin (Methocarbamol) Skelaxin (Metaxalone) Flexeril (Cyclobenzaprine) Benzodiazepines
36	Narcotics Helpful for severe, acute pain Lay out timeline to get patient off Avoid long-term use Plan for constipation, stool softeners with script
37	Physical Therapy Lumbar traction does not influence outcome at 6 weeks¹ Comprehensive physical therapy has been shown to be effective in treating chronic radicular pain² Modality care can decrease acute symptoms Stabilization and core strengthening programs best performed when pain controlled Should be used in conjunction with other treatment modalities (oral agents, injections, etc)
38	Chiropractic Care Can be effective for some types of back pain, in particular, pain from posterior elements, and musculoligamentous structures Modality care can be helpful in reducing inflammation and symptoms from discogenic pain No literature to support manipulative care aids in disc healing
39	Epidural Steroid Injections Approaches: Caudal Interlaminar Transforaminal Blind vs Flouroscopically-guided
40	Caudal Epidural Steroid Injections Effective for multilevel pathology including spinal stenosis Uses most volume of any approach Non-selective May be performed under flouroscopic guidance or blind
41	Interlaminar Epidural Steroid Injections May be done in office setting Does not require use of flouroscopy Less diagnostic, usually covers a broader area of coverage since higher volume is used Solution placed in posterior epidural space
42	Transforaminal Epidural Steroid Injections More effective than interlaminar injections Direct injectate to the anterior epidural space Diagnostic and therapeutic Lower volume of injectate Much lower risk of dural puncture and associated headache
43	Flouroscopic vs Blind Injections Flouroscopic guidance is the only way to ensure that solution travels to the target location Flouroscopy decreases risk of complications Flouroscopic guidance is more effective than blind injections Flouroscopy does have risks associated with radiation exposure, though exposure is very limited
44	Minimally Invasive Intradiscal Procedures Contained Disc Protrusion Nucleoplasty Dekompressor Viking Decompression Catheter IDD with Anular Tear IDET DiscTrode
45	IDEA - Indications Pain for > 3 months Other methods of treatment have failed IDD with anular fissure/tear Less than 50% loss of disc height Provacative discography confirms pain generator
46	IDEA A Randomized, Placebo-Controlled Trial of Intradiscal Electrothermal Anuloplasty (IDETä) for the Treatment of Chronic Discogenic Low Back Pain Kevin Pauza, Susan Howell, Paul Dreyfuss, John Peloza, Kathryn Park, Kathryn Dawson, Nikolai Bogduk
47	Intradiscal Electrothermal Anuloplasty
48	Percutaneous Discectomy - Indications Pain for > 3 months Other methods of treatment have failed Contained disc protrusion Less than 50% loss of disc height
49	Percutaneous Discectomy Lumbar discectomy (mechanical removal of the intervertebral disc nucleus pulposis) is the most commonly performed neurosurgical procedure Percutaneous discectomy was developed to reduce the complications associated with open disc surgery Between 1985 and 1992 eight studies have been done showing a 72-86% success rate in properly selected patients with a markedly reduce mobility and mortality as compared with open discectomy
50	Dekompressor
51	Open Discectomy Indicated when a definite diagnosis of a disc extrusion with sciatica or other radicular pain exists for more than 4 to 8 weeks despite conservative care More urgent if has progressive loss of motor, bladder, or bowel function or there is excruciating pain that can not be relieved by non-operative treatment Delay for longer than 6 months in face of persistent and severe symptoms may compromise best results
52	Fusion Rarely indicated for discogenic pain Last resort treatment when all else fails To be effective to treat discogenic pain, all anular material Risk failure at levels surrounding fusion
53	Red Flags Cancer Related Red Flags History of cancer Unexplained weight loss >10 kg within 6 months Age over 50 years or under 17 years old Failure to improve with therapy Pain persists for more than 4 to 6 weeks Night pain or pain at rest Cauda Equina Syndrome Related Red Flags Urinary incontinence or retention Saddle anesthesia Anal sphincter tone decreased or fecal incontinence Bilateral lower extremity weakness or numbness Progressive neurologic deficit Infection Related Red Flags Persistant fever (temperature over 100.4 F) History of intravenous drug abuse Recent bacterial infection UTI or pyelonephritis Cellulitis Pneumonia Immunocompromised states Systemic corticosteroids Organ transplant Diabetes mellitus HIV Rest Pain Acute Abdominal Aneurysm Red Flags Abdominal pulsating mass Atherosclerotic vascular disease Pain at rest or nocturnal pain Age greater than 60 years
54	Scott Kreiner, MD skreiner@ahwatukeesportsandspine.com Office: (480) 763-5808 Cell: (602) 363-6180