Blue Box Notes

Back Strain, Sprains and Spasms (p. 495) • Warm up and stretching – increase tonus of “core muscles” (anterolateral abdominal wall—transverse abdominis—lumbar stabilization) prevent back strains and sprains • Back sprain – injury to ligamentous or attachment of ligament to bone. o NOT DISLOCATION OR FRACTURE o Excessively strong contractions for extension or rotation of vertebral column • Back strain – degree of stretching or microscopic tearing of muscle fibers o Sports; overly strong contraction o Muscles usually involved with producing movement of lumbar IV joints ▪ ERECTOR SPINAE o Weight not properly balanced on vertebral column o Do NOT use back as lever, crouch and keep back straight ▪ Use muscles of butt and lower limbs • Spasm – sudden involuntary contraction of one or more muscle groups o Protective mech o Attended by cramps, pain, and interference with f(x), producing involuntary movement and distortion

Reduced Blood Supply to Brainstem (p. 496) • Winding course of vertrebral arteries through foramina transverasii of the transverse process of the cervical vertebrae and through subocciptal triangle • Problem when arteriosclerosis (hardening of arteries) – reduces blood flow • Symptoms – prolonged turning of the head such as trying to back up in car causes lightheadedness, dizziness, and other symptoms caused by blood supply to brainstem.

Compression of Lumbar Spinal Nerve Roots (p. 505) • ↑ in size of lumbar from superior ⋄ inferior, but ↓ IV foramina diameter • L5 spinal nerve roots are thickest and foramina narrowest • ↑% these narrow roots are compressed due to osteophytes (bone spurs) develop or herniation of an IV disc.

Myelography (p. 505) • Radiopaque contrast procedure that allows visualization of spinal cord and spinal nerve • CSF (withdrawn by lumber puncture) is replaced with contrast material injected into the spinal subarachnoid space • Shows extent of subarachnoid space and its extension around spinal nerve roots with dural root sheaths • High resolution MRI has supplanted this.

Lumbar Spinal Puncture • Withdrawal of CSF from lumbar cistern • Evaluate CNS disorders o Meningitis and other CNS disorders can alter CSF or change conc. Of chemical constituents • May also determine if blood present • Pt lying on side with back and hip flexed o Flexion helps because spreads apart vertebral lamina and spinous processes, stretching ligament flava • Anesthetize skin. Use lumbar puncture needle with stylet • Insert between L3/L4 (or L4/L5) o SUPACRISTAL PLANE (OH EM EMMM) o Can’t danger the spinal cord here. • 4-6 cm in adults (more for obese), needle pops through ligamentum flavum, then punctures the dura and arachnoid and enters the lumbar cistern • Stylet removed, CSF escapes at rate of one drop per second. • if subarachnoid pressure high, CSF flows out or escapes as a jet. • Not performed if ↑ intracranial pressure (within cranial cavity) o Need a ct scan or examination of the fundus (back) of the interior of the eyeball

Spinal Anesthesia (p. 506) • Injected into subarachnoid space • Anesthesia w/in a minute • Possible headache? o Leakage of CSF through lumbar puncture

Epidural Anesthesia (Blocks) (p. 506) • Injected into epidural space using lumbar spinal puncture or through sacral hiatus

Ischemia of Spinal Cord (p. 506) • Segmental reinforcements of blood supply to spinal cord form segmental medullary arteries are important in supplying blood to anterior and posterior spinal arteries • Fractures, dislocations, and combo of them may interfere with blood supply o Deficient blood supply can lead to muscle weakness and paralysis • Great anterior segmental medullary artery (of Adamkiewicz) are narrowed by obstructive arterial disease • Occlusion (cross clamped) during surgery or ruptured aneurysms of the aorta and/or great anterior segmental medullary artery can lead to lose of sensation and voluntary movement inferior to level of impaired blood supply of the spinal cord secondary to death of neurons in the part of the spinal cord supplied by the anterior spinal artery • Neurons with cell bodies distant from the site of ischemia of the spinal cord will also die, secondary to degeneration of axons traversing the site • Likelihood of iatrogenic paraplegia depends on: o Age o Extent of disease o Length of time aorta is cross clamped • Systemic BP ↓ for 3-4 mins, blood flow of segmental medullary arteries ⋄ anterior spinal artery supplying the midthoracic region of the sinal cord may be ↓ or stopped. o Lose sensation and voluntary movement in areas supplied by affected level of the spinal cord

Spinal Cord Injuries (P. 506) • Vertebral canal varies o small in cervical region o can be bad if fracture and/or disclocation ▪ damage spinal cord o protrusion of IV disc in cervical region after neck injury can cause spinal cord shock ▪ paralysis inferior to the site of lesion ▪ may not be seen til autopsy ▪ swollen ligamenta flava or from osteoarthritis of the zygapophysial joints exerting pressure on one or more of the spinal roots of cauda equine ▪ produce sensory/motor symptoms in area of distribution ▪ lumbar spondylosis (degenerative joint disease) also caused localized pain and stiffness o transection of spinal cord results in loss of all sensory and voluntary movement inferior to the lesion ▪ C1-C3: no f(x) below head level, need ventilator for respiration ▪ C4-C5: quadriplegia (no fx of upper and lower limbs); respiration occurs ▪ C6-C8: loss of lower limb fx w/ loss of hand and variable amount of upper limb fx; may self-feed or propel a wheelchair ▪ T1-T9: paraplegia (paralysis of both lower limbs); amount of trunk control varies with height of lesion ▪ T10-L1: some muscle thigh fx; walking w/ long leg braces ▪ L2-L3: most leg muscle fx; short leg brace for walking

Absence of Pectoral Muscles (p. 709) • Usually sternocostal part • No disability results • Anterior axillary fold, formed by the skin and fascia overlying the inferior border of pec major, is absent on the affected side and nipple is more inferior • Poland Syndrome – both major and minor missing o Breast hypoplasia and absence of 2-4 rib segments

Paralysis of Serratus Anterior (p. 709) • Injury to long thoracic nerve • Scapula moves medial border laterally and posteriorly away from thoracic wall • WINGED SCAPULA o Push against a wall o Arm is raised, medial border and inferior angle of scapula pull markedly away from the posterior thoracic wall • Upper limb may not be able to abduct above horizon (trap also helps) because can’t rotate glenoid cavity superior • Long thoracic protect when arms at side, but is superficial to serratus anterior o DON’T GET IN A KNIFE FIGHT OR SHOT

Triangle of Auscultation (p. 710) • Near inferior angle of scapula • Latissimus dorsi – superior horizontal border • Medial border of scapula • Inferolateral border of trapezius • Good for stethoscope • Fold arms and flex trunk, makes scapulae draw interiorly, triangle enlarges and parts of 6th and 7th rib and 6th intercostal space are subcutaneous

Injury of Spinal Nerve Accessory (CN XI) • Marked ipsilateral weakness when shoulders are elevated (shrugged) against resistance

Injury of Thoracodorsal Nerve (p. 710) • Surgery in axilla puts nerve at risk • Supplies lats • At risk during mastectomies and scapular lymph nodes surgery • Can’t raise trunk with upper limbs as occurs in climbing/gymnastics • Cannot use an axillary crutch because shoulder is pushed superiorly by it • Primary activities for which active depression of the scapula is required; passive depression provided by gravity is adequate for most activities

Injury to Dorsal Scapular Nerve (p. 710) • Supplies rhomboids • Cannot retract and rotate scapula, depressing its glenoid cavity o Also don’t assist the serratus anterior in holding the scapula against the thoracic wall, and fixing the scapula during movements of the upper limb. • If affected on one side, the scapula on affect side is located father from the midline than that of the normal side

Injury to Axillary Nerve (p. 710) • Deltoid atrophies when axillary nerve (C5 and C6) are damaged • Injured during fracture of humerus, dislocation of glenohumural joint, and by compression from incorrect use of crutches • Deltoid atrophies, get flattened appearance and produce slight hollow inferior to the acromion • Loss of sensation may occur over the lateral side of the proximal part of the arm o Area supplied by superior lateral cutaneous nerve of the arm o Cutaneous branch of axillary nerve • Deltoid common site for injection o Axillary runs transversely under cover of deltoid at level of surgical neck of humerus o Need to be aware of it for surgeries of shoulder

Fracture-Dislocation of Proximal Humeral Epiphysis (p. 712) • Direct blow or injury of a child or adolescent • Due to joint capsule, reinforced by rotator cuff (tendons of SITS muscles), is stronger than epiphyseal plate • Severe fractures: shaft of humerus is markedly displaced, but humeral head retisn its normal relationship with glenoid cavity of the scapula

Rotator Cuff Injuries (p. 712 and 814) • Injured during repetitive use of upper limb above horizontal • Inflammation of avascular area of supraspinatus tendon, is common cause of shoulder pain and results in tears of the musculotendinous rotator cuff • Baseball pitchers (repetitive use of muscles) may allow the humeral head and rotator cuff to impine of the coraco-acromial arch o Irritation of arch and inflammation of rotator cuff o Degenerative tendonitis of rotator cuff develops ▪ To test this, ask patient to fully abduct slowly and smoothly ▪ At 90 degrees, the limb will suddenly drop • Also happen when older person strain to lift something such as window stuck o Strain might rupture previous degenerated musculotendionous rotator cuff o Fall can cause this too • Shoulder stiffness occurs because intracapsular part of tendon of long head of biceps brachii become frayed, leaving it adherent to intertubercular sulcus • Fibrous layer of joint capsule is compromised o Articular cavity communicates with subacromial burse • If supraspinatus is no longer fx with complete tear, person cannot initiate abduction o If passively abducted 15 degrees, person can use deltoid

Aging of IV discs (p. 474) • ↑ age, nuclei pulposi dehydrate and lose elastin and proteoglycans while gaining collagen o IV discs lose turgor, become stiffer and more resistant to deformation o Two parts of the disc seemingly merge as one ▪ Nucleus dries and granular and may disappear altogether as a distinct formation o As these changes occur, the annulus gets ↑ share of the vertical load ⋄ stresses and strains o Lamellae of annulus thicken and often develop fissures and cavities • Though vert. bodies may approach more closely as the superior and inferior surfaces of the body become shallow concavities (Williams talking about vertebrae being mature), IV discs actually ↑ in size o Not only become convex, the anteroposterior diameter (between age of 20 and 70) increases about 10% in females and 2% in males, while thickness increases centrally about 10% in both sexes o Overt or marked disc narrowing—especially when greater than that of more superior located discs—suggests pathology not aging.

Herniation of Nucleus Pulposus (p. 474) • Protrusion of gelatinous NP into or through the annulus fibrous is a cause of lower back and lower limb pain • Herniations can also be found in asymptomatic individuals • Usually young person have strong disc and fracture before disc ruptures during fall o 90% water content, so high turgor • However, violent hyperflexion of vert. column may rupture IV disc and fracture adjacent vert. bodies • Flexion of vert. column produces compression anteriorly and stretching or tension posteriorly, squeezing the nucleus pulposus further posteriorly toward the thinnest part of the anulus fibrosus. o If the anulus fibrosus has degenerated, the nucleus pulposus may herniate into the vert. canal and compress the spinal cord or nerve roots of the cauda equine o Don’t call this a “slipped disc” • Herniations of NP usually extend posterolaterally, where AF is relatively thin and don’t receive support from posterior or the anterior longitudinal ligaments. o Posterolateral herniation is more likely to be symptomatic because of the proximity of the spinal nerve roots o acute pain ▪ Localized back of herniated disc ▪ caused from • pressure on longitudinal ligaments and periphery of the AF • local inflammation caused by chem irritation by substances from ruptured NP o Chronic pain ▪ Referred pain ▪ Compression of spinal nerve roots by herniated disc ▪ Perceived as coming from dermatome supplied by that nerve o IV discs are largest in lumbar and lumbosacral and have most movements, so most posterolateral herniations of NP here. • 95% of lumbar disc protrusions occur at the L4-L5 or L5-S1 o ↓ in IV space ⋄↓ IV foramina ⋄ exacerbating compression of the spinal nerve roots, especially if hypertrophy of surrounding bone has occurred o Acute herniation in advance years: seeing aging of IV discs ▪ Compressed by ↑ ossification of IV foramen as they exit o Acute middle and low back pain may be caused by mild posterolateral protrustion of lumbar disc at L5-S1 ▪ Affects nociceptive (pain) endings in the regions such as those with posterior longitudinal ligament ▪ Pain of acute onset is a common presenting symptom ▪ Because muscle spasm is associated with low back pain, lumbar region of the vert. column becomes tense and increasingly cramped as relative ischemia occurs, causing painful movement o Sciatica – pain in lower back ad hip radiating down back of thigh into leg ▪ Caused by herniation that compresses and compromises the L5 or S1 component of sciatic nerve ▪ IV foramina ↓ in size and lumbar nerve ↑ • Bone spurs (osteophytes) developing around zygapophysial joints may make this worse • If stretch sciatic nerve, such as flexing thigh with knee extended (straight leg raising test), may produce or exacerbate sciatic pain o IV disc damaged during violent rotation or flexing of vert. column ▪ WHEN AN IV DISC PROTRUDES, IT COMPRESSES THE NERVE ROOT NUMBERED ONE INFERIOR TO THE DISC o Spinal nerve roots descend to the IV foramen from which the spinal formed by their merging will exit ▪ Nerve that exits a given forman passes through superior bony half of the foramen and thus lies above and is not affected by disc at that level o Cervical region almost as often as lumbar region o Hyperflexion of cervical region might occur during a head on collision ▪ Football ▪ Rupture disc posteriorly w/out fracturing vert. body ▪ In this region, discs are centrally placed in the anterior border of IV foramen and a herniated disc compresses the nerve actually exiting at the level. • Don’t get confused because nerve roots are superior, so the numbering still happens ▪ Cause pain in neck, shoulder, arm, and hand ▪ Any sport or activity in which movement causes downward or twisting pressure on the neck or lower back may produce herniation

Fracture of Dens of Axis (p. 476) • Transvere ligament of atlas stronger than dens • Fracture of dens is about 40% • Most common dens fracture occurs at base • Unstable (do not reunite) because transverse ligament of atlas becomes interposed between fragments o Fragments don’t get blood supply ⋄ avascular necrosis • Fracture of body inferior to base of dens still has blood supply • Abnormal ossification patterns

Transverse Ligament of Atlas (p. 477) • Rupture ⋄ dens of axis set free ⋄ atlanto-axial subluxation – incomplete dislocation of median AA joint. o Can be caused by pathological softening of connective tissue • 20% of down syndrome have laxity or agenesis of this ligament • More likely cause spinal cord compression than resulting from fracture of dens • Dens and atlas move as a unit? • Absence of competent ligament, upper cervical region of spinal cord may be compressed o between approx..posterior arch of the atlas and dens ▪ Causes quadriplegia o Or into the medulla of the brainstem ▪ causing death • Steele’s Rule of thirds o 1/3 of atlas ring is occupied by dens o 1/3 by spinal cord o 1/3 by fluid filled space and tissues surrounding cord o Explains why some people may be asymptomatic until large range of motion • Sometimes inflammation may produce softening of ligaments o Sudden movement may produce posterior displacement of dens of axis and injury to spinal cord

Rupture of Alar Ligament (p. 477) • Alar weaker than transverse ligament • Combined with flexion and rotation of head may tear one or both alar ligaments • Results in an increase of 30% ROM to contralateral side

Fractures and Dislocations of Vertebrae (p. 477) • Sudden forceful flexion—car crash/blow to back of head—produces crush or compression fracture of body of one or more vertebrae • If violent anterior movement of the vertebra occurs in combo w/ compression, vert. may be displaced anteriorly on the vertebra inferior to it o This displacement dislocates and fractures articular facets between the two and ruptures the interspinous ligaments • Forceful extension most likely to injure posterior parts of vert., fracturing by crush or compression of vert. arches and their processes • Fractures of cervical vert. may radiate pain to the back of neck and scapular region because same spinal sensory ganglia and spinal cord segments receiving pain impulses from vert. are also involved in supplying neck muscles • In whiplash, such as car crash, severe hyperextension of neck o Head restraint too low o Anterior longitudinal ligament is severly stretched and may be torn o May also occur as neck rebounds o “facet jumping” – locking of cervical vert. may occur because of dislocation vert. arches o can produce cervical spondylolysis or hangman’s fracture o rupture the anterior longitudinal ligament and the adjacent AF of the C2-C3 disc disc ▪ cranium, C1, and the anterior portion (body and dens) of C2 are separate from rest of axial skeleton ▪ seldom survival o football, diving, fall from horses, and motor vehicle collisions cause most cervical fractures ▪ Sx range from vague aches to progressive loss of motor and sensory fx • Thoracic don’t move much, but lumbar do. o Transition causes problems o T11 and T12 most affected of fracture non-cervical vert. • Fractures in thoracic and lumber not common due to interlocking of articular processes • Spondylolysis – fracture of the column of bones connecting the superior and inferior articular processes, interlocking mech is broken o Spondylolisthesis may occur – dislocation between adjacent vert. ▪ L5 with S1. • Due to downward tilt of L5/S1 IV joint • Results from failure of centrum of L5 to unite adequately with neural arches of neurocentral joint during development • May result in pressure of spinal nerves of cauda equina as they pass into superior part of sacrum, causing lower back and lower limb pain

Injury and Disease of Zygaphysial Joint (p. 480) • Close to IV foramina • When these joints are affected by osteoarthritis, spinal nerves are often affected • Causes pain along distribution of dermatomes and spasm in the muscles derived from the associated myotomes o Myotomes consist of all muscles or parts of muscles receiving innervation from one spinal nerve • Denervation of lumbar zygapophysial joints o Treatment procedure o Nerves sectioned near the joints or are destroyed by radiofrequency percutaneous rhizolysis o Directed at the articular branches of two adjacent posterior rami of spinal nerves because each joint receives innervation from both the nerve exiting at that level and the superjacent nerve

Back Pain (p. 480) • Second most reason for visit than cold • Backache second most reason for missing work • Five categories of structures receive innervation in the back and can be sources of pain o Fibroskeletal structures: periosteum, ligaments, and af of iv discs o Meninges: coverings of the spinal cord o Synovial fluid: capsules of zygapophysial joints o Muscles; intrinsic muscles of the back o Nervous tissue: spinal nerves or nerve roots exiting the IV foramina • First two are innervated by meningeal branches of spinal nerves and the next two are innervated by posterior rami • Pain from nervous tissue—compression or irritation of spinal nerves or nerve roots—referred pain, perceives a scoming from cutaneous or subq area (dermatome) supplied by that nerve, but may be localized pain • Meninges – relatively rare • LBP is generally muscular, joint, or fibroskeletal pain o Muscular pain related to reflexive cramping, producing ischemia, often secondarily as a result of guarding o Zygapophysial joint pain is from arthritis o Pain from vert. fracturs and dislocations is no different than other bones and joints o Sharp pain is usually periosteal in origin, pain from dislocations is ligamentous

Abnormal Curvatures of Vert Column (p. 480) • To detect, person stands in Anatomical position and inspect laterally and posteriorly o Have person bend over, look at ability to flex and if even flexion • Some come from developmental abnormalities, other pathological processes o Osteoporosis • Excessive thoracic kyphosis o Hump/hunchback o Abnormal increase in curvature of area o Vert column curves posteriorly o Can be from erosion of anterior part of one or more vert. due to osteoporosis o DOWAGER’S HUMP – used for women that get this from osteoporosis ▪ Also occur in elderly men o Increase in AP diameter of thorax and sig. reduction in dynamic pulmonary capacity • Osteoporosis o Affects horizontal trabeculae of trabecular bone of vert. body ▪ Remaining, unsupported vert trabeculae are less able to resist compression and sustain compression fractures ⋄ short and wedge-shaped thoracic vert. ▪ Progressive erosion and collapse of vert ⋄ loss of height • Excessive lumbar lordosis o Hollow back or sway back o Characterized by an anterior tilting of the pelvis (upper sacrum is flexed or rotated antero-inferiorly-nutation), with an increased extension of the lumbar vert. ⋄ an abnormal increase in lumbar kyphosis o Associated w/ weakened trunk musculature, especially the anterolateral ab muscles o Late stage pregnant women develops this temporarily, which causes lower back pain. Goes back after birth o Obesity can cause this ▪ Loss of weight and exercise of anterolateral ab muscles facilitate correction of this type of excessive lordosis • Scoliosis o Abnormal lateral curvature, accompanied by rotation of vert. o Spinous process turn toward cavity of abnormal curvature, and when the individual bends over, the ribs rotate posteriorly (protrude) on the side of the increased convexity o Failure of vert. to develop (hemivertrbra) are causes of structural scoliosis ▪ Combined with excessive thoracic kyphosis – kyphoscholiosis—in which an abnormal AP diameter produces a severe restriction of thorax and lung expansion o Approx.. 80% of all structural scoliosis are idiopathic, occur without other conditions of an identifiable cause ▪ First develop in girls between 10 and 14, boys between 12 and 15 ▪ Most common and severe in females o Asymmetrical weakness of intrinsic back muscles, or a difference in the length of lower limbs with a compensatory pelvic tilt, may lead to a functional scoliosis o When a person is standing, an obvious inclincation or listing to one side may be a sign of scoliosis that is secondary to a herniated IV disc o Habit scoliosis is supposesdly caused by hapitual standing or sitting in an improper position o When scoliosis is entirely postural, it disappears during maximum flexion of vert column o F(x) scoliosis do not persist once underlying proble has been effectively treated

Vertebral Body Osteoporsis (p. 456) • Bone is reduced and atrophy of skeletal tissue occurs • Weakened, brittle, subject to fracture • Radiographs show demineralization, evident as diminished radiodensity of the trabecular spong bone of the vertebral bodies, cauing thinned cortical bone to appear relatively prominent o Especially affects horizontal trabeculae of the trabecular bone o Vertical stripping becomes apparent, reflects loss of horizontal supporting trabeculae and thickening of vertical struts • Later stages may reveal vertebral column collapse (compression factors) and increased thoracic kyphosis. o Occurs in thoracic vertebrae and postmenopausal women

Laminectomy (p. 457) • Surgical excision of one or more spinous processes and adjacent supporting vertebral laminae in a particular region of the vertebral column • Denote removal of most of vert. arch by transecting the pedicles • Performed to gain access to vertebral canal, providing posterior exposure of spinal cord (if performed above L2) and/or the roots of specific spinal nerves. • Relieve pressure on spinal cord or nerve roots caused by a tumor, herniated disc, or bony hypertrophy

Dislocation of Cervical Vertebrae (p. 457) • Have more horizontally oriented articular facets, cervical vertebrae are less tightly interlocked than other vertebrae • “stacked like coins” • Can be dislocated in neck injuries with less force than is required to fracture them • Because of the large vertebral canal, slight dislocation don’t injure spinal cord o Severe or dislocations with fractures do • If dislocation does not result in facet jumping with locking of the displaced articular processes, the cervical vertebrae may self-reduce (slip back into place) so that a radiography may not indicate that the cord has been injured o An mri may reveal the resulting soft tissue damage

Fracture and Dislocation of Atlas (p. 458) • Because taller side of the lateral mass is directed laterally, vertical forces compressing the lateral masses between the occipital condyles and the acis drive them apart, fracturing one or both of the anterior or posterior arches o Striking the bottom of the pool • If force sufficient, rupture of transverse ligament that links them will also occur o The resulting Jefferson or burst fracture in itself does not necessarily result in spinal cord injury, because the dimensions of the bony ring actually ↑ • Spinal cord injury comes from transverse ligament rupture indicated by widely spread lateral masses

Fracture and Dislocation of Axis (p. 459) • 40% caused by vert. arch fracture at C2 • Occurs in the bony column formed by superior and inferior articular processes of the axis, the pars interarticularis • Fracture called traumatic spondylolysis of C2 o Result of hyperextension of head on the neck rather than the combined hyperextension of the two, which is whiplash • Hangman’s fracture o Hyperextension of the head o Used to execute criminals by placing knot under chin before body suddenly dropped • Body of C2 vertebrae is displaced anteriorly with respect to the body of the C3 vertebra • With or without such subluxation (incomplete dislocation) of axis, injury of spinal cord and/or brainstem is likely

Lumbar Spinal Stenosis (p. 460) • Stenotic vertebral foramen in one or more lumbar vertebrae • May be hereditary anomaly ⋄ makes person more vulnerable to age-related degenerative changes such as IV disc bulging • Stenosis of a lumber vertebral foramen may cause compression of nerve occupying inferior vertebral canal • Use laminectomy • IV disc protusion, arthritic proliferation, and ligamentous degeneration makes this condition worse

Cervical Ribs (p.460) • Developmental costal of C7 • Transverse process becomes abnormally enlarged • Structure vary in size from a small protuberance to a complete rib • Supernumerary (extra) rib or a fibrous connection extending from its tip to the first rib may elevate and place pressure on structures that emerge from the superior thoracic aperture, notably the subclavian artery or inferior trunk of the brachial plexus, and may cause thoracic outlet syndrome

Caudal Epidural Anesthesia • Sacral hiatus is closed by the membranous sacrococcygeal ligament, which is pierced by filum terminale (connective tissue stran extending from the tip of the spinal cord to the coccyx) • Deep (superior) to ligament, epidural space of sacral canal is filled with fatty connective tissue • Local anesthetic agent is injected into the fat of the sacral canal that surrounds the proximal portions of the sacral nerve • This can be accomplished by several routes, including the hiatus • Because the hiatus is located between the sacral cornua and inferior to the S4 spinous process or median sacral crest, these palpable bony landmarks are important for locating the hiatus • Anesthestic solution spreads superiorly and extradurally, where it acts on the S2, Co1 spinal nerves of the cauda equina. • Height depends on amount and position of patient • Sensation is lost inferior to epidural block • Anesthetic agents can also be injected through the posterior sacral foramina into the sacral canal around the spinal nerve roots

Injury of Coccyx (p. 461) • Subperiosteal bruising or fracture of the coccyx, or fracture-dislocation of the sacrococcygeal joint. o Fall on your ass • Displacement is common and surgical removal of fractured bone may be required to relieve pain • Childbirth can injure the mother’s coccyx • Coccygodynia often follows coccygeal trauma; pain relief is commonly difficult

Abnormal Fusion of Vertebrae (p. 462) • L5 is completely or partially incorporated into sacrum • 5% of people • Known as hemisacrilization or sacralization of L5 vertebra • L5-S1 strong and L4-L5 degenerates, produces pain • Others have S1 more or less separated from sacrum and is partly or completely fused with L5 vertebra o Lumbarization of the S1 vertebra

Effect of Aging on Vertebrae (p. 462) • Between birth and 5, body of a typical lumbar increases in height 3-fold • Between 5 and 13, it increases another 45-50% • Continues until 18-25, but decreased rate • Older age, bone density low o Articular surface gradually bow inward ⋄ both inferior and superior surfaces become concave and the IV discs become convex o Account for slight loss in height o Apparent narrowing on radiographs ▪ Do not interpret as loss of IV disc thickness • Aging in IV dscs and changing shape of vertebrae results in ↑ in compression forces of the periphery of vertebral bodies, where the discs attach. o In response, osteophytes (bone spurs) commonly develop around margins of vertebral body, especially anteriorly and posteriorly • Osteophytes also develop along the attachment of joint capsules and accessory ligaments, especially those of the superior articular process, whereas extensions of the articular cartilage develop around the articular facets of the inferior processes • May be pain or not • Not pathological, but rather anatomical.

Anomalies of Vertebrae (p. 463) • Epiphysis of transverse fails to fuse o Caution not to mistake a persistent epiphysis for a vertebral fracture in a radiograph or CT scan • Spina Bifida occulta o Birth defect o Neural arches of L5 and.or S1 fail to develop normally and fuse posterior to vertebral canal o Present in up to 24% of the population, occurs in vertebral arch of L5 and/or S1 o Concealed by the overlying skin, but its location is often indicated by a tuft of hair o No back problems o When examining a newbord, adjacent vertebrae should be palpated in sequence to be certain the vertebral arches are intact and continuous from the cervical to the sacral regions • Spina Bifida cystica o 1 or more arches may fail to develop completely o Associated with herniation of the meninges and/or spinal cord o Neurological symptoms are present with severe cases of meningomyelocele (spina bifida associated with a meningeal cyst) ▪ Paralysis of limbs and disturbances in bladder and bowel control o Result from neural tube defects, such as defective closure of neural tube during the 4th week of embryonic development

Forearm (p. 766) • Elbow Tendinitis or Lateral Epicondylitis o may follow repetitive use of SUPERFICIAL EXTENSOR muscles o pain is felt over lateral epicondyle and radiates down o repeated forceful flexion/extension of the wrist strain the attachment to the common extensor tendon causing inflammation • Mallet or Baseball finger o severe tension on a long extensor tendon may avulse part of its attachment to phalenx causing “baseball finger” o results from the DIP joint being forced into extreme FLEXION ▪ this tears away tendon attachment at base of phalanx ▪ thus, person can’t EXTEND DIP joint • Fracture of Olecranon o usually occurs from fall to elbow with powerful contraction of the triceps brachii • Synovial Cyst of the wrist o flexion of the wrist makes these worse o the distal attatchment of the ECRB tendon to the base of the 3rd metacarpel is a common site for this o cystic swelling of common flexor synovial sheath of anterior aspect of the wrist can enlarge and compress the median nerve by narrowing the tunnel leading to carpel tunnel syndrome • Median nerve injury o if severed at the elbow, flexion of PIP (digits 1-3) is lost and flexion of the 4th and 5th digits are weakened o flexion of DIP joints of digit 2-3 is also lost o flexion of DIP in digit 4-5 is NOT affected bc the flexor digitorum profundus is also innervated by the ulnar nerve o thenar muscle function is also lost o if anterior interosseous is affected, there is partial paralysis of of flexor digitorum profundus and flexor pollicis longus ▪ Anterior interosseous syndrome • patient ok sign disrupted and pinch sign instead • pronator syndrome o a nerve entrapment syndrome caused by compression of the median nerve near the elbow between the heads of the pronator teres o pain and tenderness of proximal anterior forearm is noted • Injury of Ulnar Nerve at Elbow and in forearm o occur in 4 places ▪ posterior to the medial epicondyle of the humorous (most common) ▪ in the cubital tunnel formed by the tendinous arch connecting the humeral and ulnar heads of the Flexor Carpi Ulnaris ▪ at the wrist ▪ in the hand o usually occurs from knocking your elbow o numbness and tingling of medial part of palm and medial 1.5 fingers o can result in extensive motor and sensory lose of the hand o can deinnervate important hand muscles ▪ wrist adductors ▪ person has difficulty making a fist ▪ in absense of opposition MP joints become hyperextended and there is no flexion of 4th/5th digit when making a fist ▪ cannot extend interphalangeal joints when trying to straighten hand (CLAW HAND) • Cubital Tunnel Syndrome o ulnar nerve compressed in cubital tunnel o same symptoms as ulnar nerve injury • Injury of Radial Nerve in Forearm (superficial or deep branched) o usually injured in the arm from HUMORAL fracture o radial has motor branches to long and short extensors of wrist so WRIST DROP OCCURS o can access integrity of deep branch by inability to extend MP joints against resistance

Hand (Pg 789) • Dupytren Contracture of Palmar Fascia o results in progressive shortening, thickening, and fibrosis of palmar fascia o this pulls digit 4/5 into flexion at MP and PIP joints

• Hand infections o swellings from hand infections usually appear on the dorsum of the hand where the fascia is thinner compared to the very thick palmar fascia o fascial spaces determines pus spread of these infections • Tenosynovitis o when finger puncture by something such as a nail can cause tendon and synovial sheath inflammation o the the tendons of digit 2,3, and 4 have separate synovial sheaths so the infection is usually confined to the infected finger o but puncture of little finger is continous ▪ infection can spread to the common sheath and go to the palm of the hand, carpal tunnel, and to the anterior forearm in the space bt the ponator quadratus and flexor tendons o tendons of APL and EPB are the same tendon on the dorsum of the wrist o excessive friction of these tendons can cause fibrous thickening of sheath and lead to QUERVAIN TENOVAGINITIS STENOSANS ▪ pain in wrist that radiates to the thumb o If FDS and FDP enlarge proximal to tunnel, the person may be unable to extend finger this is know as TRIGGER FINGER • Laceration of palmar Arches o when palmar (arterial) arches are lacerated, bleeding is profuse o thus during surgeries to that area it may be necessary to compress the brachial artery and its branches that are proximal to the elbow • Ischemia of Digits o Ischemia of digits, paresthesia, pain o Raynaud syndrome o to treat cervicodorsal pre-synaptic sympathectomy is needed to dialate the artery • Lesions of median nerve (usually occur in wrist and forearm) o Carpal Tunnel-syndrome ▪ results from lesions that reduce the size of the carpal tunnel or increase the size of things that pass through it ▪ fluid retention or exercise may cause swelling of the synovial sheath ▪ median nerve supplies sensory to first 3 digits therefore if damaged sensory lost (tingling, numbness) of these digits may occur (but sensation in the palm remains!) ▪ loss of coordination and weakness in thumb • due to loss of Abductor pollicis breves and opponens pollicis (remember LOAF is innervated by median nerve in the hand)

o Trauma to median nerve ▪ median nerve is close to surface near wrist ▪ in suicide attempts this is what is cut • paralysis of thenar muscles and lumbricals 1 and 2 • BUT Abductor pollicis longus and adductor pollicis which is supplied by the posterior interoseaous and ulnar nerves may try to imitate opposition but ineffectively • ability to flex thumb MP joints is also affected since the lumbricals are innervated by median nerve o SIMIAN HAND ( a deformity in which thumb movements are limited to flexion and extension of the thumb in the plane of the palm) ▪ this is caused by the inability to oppose and by limited abduction of the thumb • Ulnar canal syndrome o compression of ulnar nerve may occur at the wrist where it passes bt the pisiform and the hook of hamate o hypoesthesia in the medial 1.5 fingers and general weakness of the INTRINSIC hand muscles o clawing of the 4th and 5th digit (hyperextension of MP with flexion in PIP) o in contrast to ulnar nerve injury: ability to flex is unaffected and no radial deviation of the hand • Handlebar Neuropathy o those with hands in extended position for a long time (bike riders) put pressure on hooks of hamate which compresses the ulnar nerves o results in sensory loss on digit 4/5 and weak intrinsic hand muscles

• Radial Nerve injury in arm and hand disability o EVEN THOUGH NO MOTOR SUPPLY TO HAND radial nerve injury can still cause hand disability o inability to extend the wrist is characteristic (wrist drop) due to paralysis of forearm extensor muscles o fingers of the relxed hand remain in flexed position at the MP joints

• Palmar wounds and surgical Incisions o know that the superficial palmar arch is at the same level as the distal end of the common flexor sheath o wounds along the medial surface of the thenar eminence may injure the recurrent bran of the median nerve to the thenar muscles