BACK PAINBACK PAIN

Disc herniation

HistoryHistory

Primitive cultures attributed it to the work of demons

Ancient Greeks recognized the symptoms as a disease

Goldthwait in 1911 attributed back pain to posterior dislacement of the disc (disc tumor)

Barr in 1932 attributed sciatica to herniated lumbar disc –suggested surgical treatment

epidemiologyepidemiology

Hult estimates 80% of people are affected by this symptom at some time in their lives (Acta Orth Scand 1954)

Dillane,fry and Kalton reported 79% of men 89% of women the specific cause was unknown( BMJ 1966)

epidemiologyepidemiology

Saal and Saal noted: 80% of those reporting chronic back pain did not report limitation of activity

Females more frequently than malesNo racial differences

epidemiologyepidemiology

Carey et al 1992: incidence 3.9% chronic low back pain in 4437 North Carolinians

34% of those permanently disabled

CostCost

Lost work timeCompensation (~~2 billion $/year in USA)Treatment (1/3 total cost)

Factors affecting…..Factors affecting…..

Jobs requiring heavy and repetitive lifting,use of machine tools,operation of motor vehicles

Cigarette smokersAnxiety, depression, stressful occupationsNumber of pregnancies

Frymoyer et al JBJS 1983

……..

Scoliosis

Jackson,Simmons Spine 1983

Patients taller than 181cm

Gyntelberg F Dan Med Bull 1974

Obesity

Deyo,Bass Spine 1989

Disc anatomyDisc anatomy

Nucleus pulposusNucleus pulposus

Loose,nonoriented,collagen fibril framework supporting a network of cells resembling fibrocytes and chondrocytes

Gelatinous matrix of various glucosaminoglycans,water and salts

Annulus fibrosusAnnulus fibrosus

Concentric rings of fibrocartilaginous tissue

Rings attach to each other with additional diagonal fibers

Rings are thicker anteriorly

Neural elementsNeural elements

Neural fibers exist in the outer rings of the annulus

They are branches of sinu vertebral nerve lying dorsally (small filamentous nerve originates from ventral ramus)

Bogduk N : Spine 7:319 1982

Natural historyNatural history

Stage I : Dysfanction

15-45 y old,circumferential & radial tears in disc annulus, localised synovitis of facets

Stage II: Instability

35-70y old, internal disc disruption, progressive disc resorption, facet degenaration,sublaxation, joint erosion

Natural historyNatural history

Stage III : Stabilisation

Osteophytes, stenosis, spondylosis

Kirkaldy-Willis Spine 4:102-109, 1979

Disc disease :one of recurrent episodes of pain followed by periods of significant or complete relief

Simple compression of nerve Simple compression of nerve root creates sensory & motor root creates sensory & motor

symptoms but no painsymptoms but no pain

Smyth MJ, Wright V JBJS Smyth MJ, Wright V JBJS 40A:1401-1418 195840A:1401-1418 1958

Chronic irritation by Chronic irritation by compression tends to be compression tends to be

painfulpainfulSmyth,Wright JBJS 1958Smyth,Wright JBJS 1958

Howe,Laser,Calvin Pain 3:25-Howe,Laser,Calvin Pain 3:25-41,197741,1977

Consequences of pressureConsequences of pressure

Alteration in intraneural blood flowProblems with axoplasmic transportInflamation, edema, demyelination

Nobuhiro H,Hwan-Mo L,Weinstain JN textbook of spinal disorders 1996

Rydevik BL,Brown MD,Lundberg G : Spine 9:7-15 1984

Kawakami et alKawakami et alJournal of Orthopaedic Journal of Orthopaedic

Research vol 18-2, 2000Research vol 18-2, 2000Mechanical constriction leads to

demyelination,alters pain related behaviorNucleus pulpusus:mechanical hyperalgia4-0 silk loop: no hyperalgiaSilk loop +nucleus pulpusus: thermal

hypralgesia

Park JB,Chang H,Kim YS Park JB,Chang H,Kim YS Spine 1;28(1):100 2003Spine 1;28(1):100 2003

Immune reactionIncrease interleukin 12,T-helper Type I,

interferone-gamma(INF-gamma),Th2(IL-4)

Kawakami et al Spine Kawakami et al Spine 21(18):2101-2107 199621(18):2101-2107 1996

pHInterleukin IPhospholipase A2Nitric Oxide

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