spine injuries in baseball players | cervical spine injuries | colorado spine surgeon

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  • Recognition and Treatment of Cervical Disorders in Baseball ProfessionalsDonald S. Corenman, M.D., D.C.Steadman Clinic- Vail, ColoradoNeckandback.com

  • General Spine Trauma EtiologyMVA 45%falls 20%sports 15%violence 15%misc. 5%

  • Baseball has a very low percentage of traumatic spinal injuries- so what disorders do they develop?

  • Aggravation of Degenerative Disc DisordersAnnular TearsDegenerative Disc Disease/ Isolated disc resorptionFacet DiseaseHerniated Nucleus Pulposis/ RadiculopathyStretch Radiculopathy/ PlexopathyForaminal stenosis- radiculopathyCervical Stenosis/ MyelopathyDeconditioning/ abnormal biomechanics

  • Cervical Spineweight bearing 15-20 poundsspecialized vertebra (C1 and C2)spinal cordLordosis from trapezoidal discsthinner annulusUncovertebral jointsSmall neural foramen

  • Annular AnatomyAnnular fibers are in lamina (layers)Approximately 60 layers from outside to innermostWhen nucleus loses hydration (aging)- pressure drops and more stress on annulusRotation stretches 50% of fibers (and relaxes the other 50%)Disc loses 50% of strength by rotationFlexion loads disc and stretches fibers (possibly to failure)

  • Circulatory Changes in the DiscNotochord turns into nucleus of discVascularity of disc diminishes arterioles lose their access to the disc as the endplate maturesDisc becomes more avascular over time (largest mass of avascular tissue in the body)Imbibition- only nutrient exchange after this point

  • Biochemical Changes to the Intervertebral DiscImbibition- poor exchange of nutrientsLactate levels build and pH drops- especially in the center of the nucleusInternal cell metabolism dropsHydrophyllic proteoglycans break down and are not replacedPressure drops in nucleus as a resultIncreased stress on the annulusGenetic history

  • Mechanical Changes to the DiscPressure drop from dissolution of hydrophyllic proteoglycansAberrant motion to posterior annulusTears occur in annulus fibrosisDisc height reduction imbricates facetsAbove causes disc to become less able to compensate for loading

  • Discal Changes with AgingAfter skeletal maturity, type I collagen increases and discal water decreases (stiffens disc)O2 concentration is 20-30X greater at periphery of disc than at center (imbibition)Chondrocyte cells decrease and necrotic cells can be identifiedEntire disc appears disorganizedLarge voids appear (vacuum sign)Peripherally- osteophyte formation (enthesopathy)

  • Degenerative CascadeDisc loses hydrationDisc walls subjected to shear and torsionAnnulus disintegratesBone now absorbs shockMicrofracturesPatient Wiring

  • EnthesopathySharpys fibers connect annulus to boneWhen these undergo traction by aberrant motion, periosteum is also pulled offNew bone formation occurs at junction of periosteum, bone and Sharpys fibersMost common cause of foramenal stenosis and cervical radiculopathy

  • Pain Origination

  • Why do we need pain receptors in the first place?Nociceptors are important to signal damaging motion to the disc and bone of the vertebraWithout this feedback of noxious stimulus, a Charcot spine developsDestruction occurs in any joint that has no feedback mechanism by overload and motion beyond tissue tolerance

  • Smyth and Wright, JBJS(B) 40A intraoperative connection of nylon threads to spinal structures with post-operative stimulation Tension on normal nerve root produced no sciaticaInterspinous ligament and Ligamentum Flavum produced no painDura Mater was generally insensitiveThe greater the pressure to a compromised nerve root, the greater the length of radiated pain

  • Kuslich, OCNA April 91pain response to tissue stimulation under local anesthesia

    Capsule- rarely generated any pain upon stimulation. (Lumbar normal facets)Muscle could produce sharp pain with forceful stretching but only rarely simulated the deep dull ache of lumbagoNormal Nerve Root- completely insensitive to pain, forceful prolonged retraction caused mild paresthesias only

  • Kuslich, OCNA April 91 pain response to tissue stimulation under local anesthesiaSciatica- only by stimulation of swollen or stretched nerve rootsBack Pain- stimulation of outer layer of posterior annulus and PLLButtocks Pain- simultaneous stimulation of annulus and nerve root

  • Cortical Pain IdentificationHomunculus of cerebral cortex dedicated to only certain number of receptors in each areaNeck and lower back have minimal number of receptors compared to other regional areas of coverage

  • Referral PainCloward, Dwyer, BogdukThought to be generated in the cord from strong impulses that spread from internuncial neuronsAssociated with somite originSympathetic afferents?

  • Physical Examination

  • Sensory EvaluationC1- no rootC2-3- greater/lesser occipital nerveC4- posterior neck and anterior chest (cervical angina)C5- deltoid (lat shoulder)C6- thumbC7- long fingerC8- little fingerT1-ulnar forearm/arm

  • Motor InnervationC3- No motor (ansa cervicalis) C4- No motor (ansa cervicalis)C5- deltoidC6- biceps, supinator, wrist extensorsC7- triceps, wrist flexors, MCP extensorsC8- grip (poorest recovery)T1- intrinsics (finger abductors)

  • Myelopathic SymptomsLhermittes signMyelopathy handParesthesiasIncoordination of gaitBowel and bladderPain in nonradicular distribution

  • Myelopathy SignsHyperreflexiaClonusInverted radial reflexHoffmans signLhermittes signPsoas WeaknessMyelopathy hand

  • Myelopathy- Spinal Canal MeasurementsCritical Diameter- 13mm (Veidlinger)Torg RatioKinetic Aspects of compression

  • Central Cord SyndromeThe most common and most missed of all cord injuriesHallmark is temporary paralysis that normally disappears from 2min to 2 hoursBurning of dorsum of handsArm greater than leg symptomsImmobilize and transport!

  • Cervical HNPNeck, arm and posterior scapular painGreater the compression, pain radiates further down the armMotor, sensory, reflex, cord signsBetter with neck flexion, arm external rotation/ abduction (Bakodys sign)

  • Selective Motor Root CompressionSelective compression of motor rootPainlessAnterior/ posterior roots dont join until almost past DRGAnterior root is motor branch

  • Selective Motor Root Compression

  • Facet BlocksFacets considered as 40% of axial pain generators (Bogduk)Referral pain patterns mimic headaches, shoulder pain and thoracic painMRI and CT normally negative (non-diagnostic)Motion palpation is valuable diagnostic screenOnly diagnostic tool is facet blockCapsular injections vs. medial branch blocks

  • Surgical IndicationsAlways conservative treatment unless significant motor deficit, myelopathy or severe painMotor deficitMyelopathySevere painInstability? Quicker functional recovery?

  • ACDFOne level is a home run operation with greater than a 95% success rateBack to full active participation in 8 weeksMore than two levels associated with junctional breakdown in higher level sports

  • Decompressing Canal

  • Post Op ACDF

  • Successful Artificial Disc CharacteristicsDisc must recreate the biomechanics of the original discFacet joints must be normal and not overloadedWear characteristics long termShock absorptionAbility to revise easilyLow failure rateAppropriate indications

  • Artificial Disc ProblemsTotal knee or hip- 10-15 year life expectancyCurrent discs dont have shock absorption capabilityCervical discs may have too much freedom of motion- overload facetsFailure associated with wear debris- granulomas, bone loss, adhesions to local structures

  • Thank You