2 Spine • TRAUMA
Subluxation with angulation Ͼ3.5 mm
greater than 11° and/or
anterior displacement
greater than 3.5 mm
generally indicative of
instability
Ͼ11˚
Subluxation with angulation Anterior displacement
greater than 11˚ greater than 3.5 mm
Facet dislocation
Anterior facet dislocation of C5 on C6 with X-ray (lateral view) shows bilateral facet
tear of interspinous ligament, facet capsules, dislocation at C5–C6
and posterior fibers of intervertebral disc
DESCRIPTION EVALUATION CLASSIFICATION TREATMENT
SUBAXIAL CERVICAL FRACTURES
• Compression fx: involve Hx: High-energy trauma, By mechanism (each class • Compression fx: collar
(e.g., MVA, fall, diving), is subclassified by severity) • Burst fx: ACDF (anterior
ant. half of vertebral body ϩ/Ϫ pain, numbness, tin- 1. Flexion-compression [#1]
gling or weakness 2. Vertical compression corpectomy, diskec-
• Burst fx: involve whole PE: Stabilize head & neck 3. Flexion-distraction [#2] tomy, and fusion
Palpate neck for “step off.” 4. Extension-compression [ant. plate]) vs
vertebral body & have ret- Neuro exam: CN’s, UE & 5. Extension-distraction decompression/post.
LE motor/sensory/ 6. Lateral flexion fusion)
ropulsion into spinal canal reflexes • Flexion-compression:
XR: Lateral, odontoid, AP Descriptive ؠStable: collar or halo;
• Instability (White & Panjabi) Evaluate for stability Compression ؠUnstable: ant. or
ؠϾ3.5mm of translation criteria Burst
ؠϾ11° kyphotic Flexion/extension views: Facet dislocation post. fusion
angulation to evaluate dynamic Unilateral • Flexion-distraction/
ؠϩ stretch test instability Bilateral
ؠNeuro (cord or root) CT: Best study for all facet dx: Closed (acute,
injury fractures awake pt) vs open
ؠAnt. elements destroyed MR: Assess posterior liga- (unconscious or late
ؠPost. elements ments & for disc hernia- presentation) reduction
destroyed tion on cord with anterior (ACDF) or
ؠNarrow spinal canal posterior spinal fusion
ؠDisc space narrowing
• Heavy loads anticipated
COMPLICATIONS: Neurologic: quadriplegia, paraplegia, radiculopathy. Vascular: vertebral artery. Immobilization: halo.
40 NETTER’S CONCISE ORTHOPAEDIC ANATOMY
Three-Column Concept of Spinal Stability TRAUMA • Spine 2
Posterior Middle Anterior Posterior Middle Anterior Burst fracture
column column column column column column
Three-column concept. If more than Lateral view. Note that lateral facet Burst fracture of unstable vertebral
one column involved in fracture, (zygapophyseal) joints in posterior body involving both anterior and
then instability of spine usually column, with intervertebral foramina middle columns resulted in instability
results in middle column and spinal cord compression
Chance fracture
Flexion
Distraction results in complete transverse
fracture through entire vertebra. Note hinge
effect of anterior longitudinal ligament
Fracture/Dislocation:
All 3 columns are involved
DESCRIPTION EVALUATION CLASSIFICATION TREATMENT
THORACOLUMBAR FRACTURES
• Mechanism: MVA or fall Hx: High-energy trauma, Compression: 1 (anterior) • Compression: observation
(lap belt can be fulcrum pain ϩ/Ϫ numbness or column only, stable fx or orthosis 12wk
to cause flexion- weakness Stable burst: 2 columns
distraction fx) PE: Palpate for “step off” 1. Ͻ25º kyphosis • Stable burst: TLSO or hy-
Neuro exam: LE motor/ 2. Ͻ50% body ht loss perextension brace for
• Thoracolumbar junction sensory/reflexes 3. Ͻ50% canal 12wk (f/u x-rays to con-
is most common site (including anal wink retropulsion firm stability)
of fracture/injury & bulbocavernosus) Unstable burst: 2-3 col-
XR: Lateral (body ht, umns fail above criteria • Unstable burst: decom-
• Determining stability kyphosis) or have neurologic com- pression & posterior
is key to treatment AP (pedicle widening) promise spinal fusion
Flexion/extension views: Flexion-distraction:
• 3-column theory to evaluate dynamic 2-3 columns; columns • Flexion-distraction: most
(Denis): Ͼ1 column in- instability fail posterior to anterior require posterior fusion
jured ϭ unstable CT: Best study for all Translation (fx/dx): All
fractures 3 columns fail: unstable • Translation: needs reduc-
• Burst fx: caused by Evaluate for retropulsion tion and stabilization/
1. flexion and 2. axial MR: Discs & post. ligaments fusion
compression
• Chance fx: flexion-
distraction fx, all 3 col-
umns fail in tension
COMPLICATIONS: Neurologic: Spinal cord/cauda equina injury. Immobilization: DVT, PE. Surgical: Infection, dural tears.
NETTER’S CONCISE ORTHOPAEDIC ANATOMY 41
2 Spine • TRAUMA
Central cord syndrome
Central cord hemorrhage and
edema. Parts of 3 main tracts
involved on both sides. Upper
limbs more affected than lower
limbs
Anterior spinal artery syndrome
Artery damaged by bone or cartilage spicules
(shaded area affected). Bilateral loss of motor
function and pain sensation below injured
segment; position sense preserved
Brown-Sequard syndrome
One side of cord affected. Loss of motor
function and position sense on same side
and of pain sensation on opposite side
Posterior column syndrome (uncommon)
Position sense lost below lesion; motor
function and pain sensation preserved
DESCRIPTION EVALUATION CLASSIFICATION TREATMENT
SPINAL CORD TRAUMA
• Young males most Hx: High-energy trauma • Complete: no function • Methylprednisolone IV
common (MVA, fall), ϩ/Ϫ numbness below the injured level given within 8hr of in-
or weakness (spinal shock must be re- jury may improve func-
• High association PE: Find lowest functional solved to diagnose) tional level
w/C-spine fractures neurologic level
(easily missed) Central: UEϾLE motor loss • Incomplete: partial spar- • Most patients recover
Anterior: LEϾUE motor and ing of distal function 1 (or 2) levels of func-
• Central: #1, hyperexten- sensory, proprioception ؠCentral: central gray tion in complete
sion mechanism, seen intact matter injuries
in elderly, with cervical B-S: Ipsilateral motor loss, ؠAnterior: Spinothalamic
spondylosis contralateral pain/temp & corticospinal tracts • Decompression of cord
loss out, posterior columns (reduce dislocations or
• Anterior: #2, worst XR: r/o C-spine fx spared remove bone frag-
prognosis CT: r/o or evaluate C-spine fx ؠBrown-Sequard: lat- ments) with internal or
MR: Shows cord, disc herni- eral half of spinal cord external (e.g., collar or
• Brown-Sequard: usually ation (on cord), posterior (“hemisection”) halo) immobilization
penetrating trauma, rare ligaments ؠPosterior: posterior col-
injury, best prognosis umns
• Posterior: very rare; this
pattern may not exist
COMPLICATIONS: Neurologic; autonomic dysreflexia (treat with urinary catheter/rectal disimpaction); spinal instability.
• Spinal shock: Paralysis/areflexia from physiologic cord injury. Return of bulbocavernosus reflex is end of spinal shock.
• Neurogenic shock: Hypotension with bradycardia. Decreased sympathetic (unopposed vagal) tone. Treat with
vasopressors.
• Hypovolemic shock: Hypotension with tachycardia. Treat with fluid/volume resuscitation.
42 NETTER’S CONCISE ORTHOPAEDIC ANATOMY
JOINTS • Spine 2
Alar ligaments
Cruciate Superior longitudinal band Atlas (C1)
ligament Transverse ligament of atlas Axis (C2)
Inferior longitudinal band
Deeper (accessory) part of tectorial membrane
Principal part of tectorial membrane removed
to expose deeper ligaments: posterior view
Atlas (C1) Apical ligament of dens
Axis (C2)
Alar ligament
Posterior articular facet
of dens (for transverse
ligament of atlas)
Alar ligament Anterior tubercle of atlas
Synovial cavities
Cruciate ligament removed to show
deepest ligaments: posterior view
Dens Transverse
ligament
of atlas
Median atlantoaxial joint: superior view
LIGAMENT ATTACHMENTS COMMENTS
OCCIPITOATLANTAL JOINT
• Articulation between convex occipital condyles and concave superior facets of atlas (C1). This articulation is horizontal
(especially in pediatrics) allowing for rotation, but is inherently horizontally unstable. ROM: flexion/extension 25°; lat-
eral bending 5° (each side); rotation 5° (each side).
Capsule Surrounds joints (condyle & facet) Loose tissue provides minimal stability
Ant. atlantooccipital Ant. atlas arch to ant. foramen mag. Continuation of ALL
Tectorial membrane Post. axis to ant. foramen magnum Primary stabilizer. Continuation of PLL, limits extension
Post. atlantooccipital Post. arch to post. foramen magnum Homologous to ligamentum flavum
ATLANTOAXIAL JOINT (C1-2)
• Made up of 3 articulations: Central (median) atlantoaxial joint (pivot type): between the odontoid and anterior arch. Lat-
eral atlantoaxial joints [2] (plane type): between the articulating facets of atlas and axis, allow for rotation. ROM: flex/
extend 20º; lateral bending 5º (each side); rotation 40º (each side). Supplies 50% of cervical rotation.
Capsule Surrounds lateral facet joints Loose capsule allows for rotation
Cruciate Posterior odontoid to anterior arch Has 3 components, is anterior to tectorial membrane
Transverse atlantal Strongest ligament, holds odontoid to atlas. ADI
Odontoid to ant. foramen magnum Ͻ3mm. Injury results in C1-2 instability.
(TAL) Odontoid to body of axis Posterior to apical ligament, secondary stabilizer.
Superior longitudinal Secondary stabilizer
Inferior longitudinal
Alar Odontoid to occipital condyles Strong, stabilizing ligaments, limit rotation & lateral
bending. Injury results in C1-2 instability.
Apical Odontoid to ant. foramen magnum Thin ligament provides minimal stability
Accessory Axis body to occipital condyles Secondary stabilizers
NETTER’S CONCISE ORTHOPAEDIC ANATOMY 43
2 Spine • JOINTS
Clivus (surface feature) Tectorial Anterior view Basilar part of
of basilar part of occipital bone membrane occipital bone
Capsule of Atlas (C1) Pharyngeal
atlantoocci- tubercle
pital joint Capsule of lateral
atlantoaxial joint Anterior
Deeper atlantooccipital
(accessory) part Axis (C2) membrane
of tectorial Capsule of zygapophyseal
membrane joint (C2—3) Posterior atlanto-
Capsule of zygapophyseal occipital mem-
Posterior joint (C3—4) brane
longitudinal
ligament Capsule of
atlantooccipital
joint
Lateral atlantoaxial
joint (opened up)
Anterior longitudinal
ligament
Vertebral artery Hypoglossal canal
Tectorial membrane
Posterior margin Basion
of foramen magnum Apical ligament of dens
(opisthion)
Posterior atlanto- Superior longitudinal band of
occipital membrane cruciate ligament of atlas
Posterior arch of atlas (C1) Anterior atlantooccipital membrane
Ligamentum nuchae
Anterior arch of atlas (C1)
Posterior atlantoaxial
membrane Articular cavity
Spinous process of axis (C2) Dens (odontoid process) of axis (C2)
Ligamentum flavum Transverse ligament of atlas
Inferior longitudinal band of
cruciate ligament of atlas
Anterior longitudinal ligament
Posterior longitudinal ligament
LIGAMENT ATTACHMENTS COMMENTS
INTERVERTEBRAL ARTICULATION
Adjacent vertebrae are joined by a complex of smaller joints/articulations, ligaments, muscles, & connecting structures.
• An intervertebral disc lies between the vertebral bodies (except b/w C1-2 and b/w the fused sacral segments).
• Paired facet (apophyseal) joints connect the posterior elements. Their orientation dictates that intervertebral motion.
• Uncovertebral joints (of Luschka) add stability between vertebral bodies in the cervical spine.
Intervertebral disc To adjacent vertebral bodies Annulus gives strong connection b/w adjacent bodies
Anterior longitudinal Adjacent anterior vertebral bodies Strong, thick ligament. Resists hyperextension.
ligament (ALL) and discs
Posterior longitudi- Adjacent posterior vertebral bodies Weak, limits hyperflexion. Disc herniates around
nal ligament (PLL)
& discs (full length of spine) ligament.
Tectorial membrane is the superior continuation.
Ligamentum flavum Anterior lamina (superior vert.) to Strong, yellow, not a long continuous structure.
posterior lamina (inferior vert.) Hypertrophy may contribute to nerve root impingement.
Ligamentum nuchae Occipital protuberance to C1 post. Continuation of supraspinous ligament
arch & C2-C6 spinous processes
Supraspinous Dorsal spinous processes to C7 Strong. Ligamentum nuchae is its superior continuation.
Interspinous Between spinous processes Weak. Torn in ligamentous flexion-distraction injuries.
Intertransverse Between transverse processes Weak ligament, adds little support.
Iliolumbar L5 transverse process to ilium May avulse in pelvic fracture (e.g., vertical shear fx).
44 NETTER’S CONCISE ORTHOPAEDIC ANATOMY
Left lateral view JOINTS • Spine 2
(partially sectioned
in median plane) Inferior articular process
Anterior Capsule of zygapophyseal
longitudinal ligament (facet) joint (partially opened)
Superior articular process
Lumbar vertebral body Transverse process
Spinous process
Intervertebral disc Ligamentum flavum
Interspinous ligament
Anterior Supraspinous ligament
longitudinal ligament Intervertebral foramen
Posterior
longitudinal ligament
L1 Conus medullaris
Cauda equina
Intervertebral disc
Pedicle (cut)
Intervertebral
disc
L5 Posterior
longitudinal
S1 ligament
Superior articular processes;
facet tropism (difference in
facet axis) on right side
Lumbar MRI, sagittal view Spinous process Pedicle
Lamina
Pars inter-
Transverse process articularis
Inferior articular process
Ligamentum flavum
Iliolumbar ligament
Iliac crest
Posterior view
NETTER’S CONCISE ORTHOPAEDIC ANATOMY 45
2 Spine • JOINTS
Facet joint Superior Facet joint Facet joint and
articular Joint capsule capsule innervated
process by dorsal rami
Bilevel from two spinal
Inferior innervation levels
articular of synovial
process membrane Annulus
and capsule fibrosis
Facet joint, composed of articular of facet joint
processes of adjacent vertebrae, Vertebral body
limits torsion and translation Facet joints
Nucleus pulposus
Anterior
longitudinal
ligament
Annulus fibrosus
Nucleus
pulposus
Intervertebral disc
LIGAMENT ATTACHMENTS COMMENTS
FACET ([ZYG]APOPHYSEAL) JOINT
Paired (L & R) articulations between the inferior & superior articular processes of adjacent vertebrae.
• Orientation changes from semi-coronal (cervical) to sagittal (lumbar) and allows/dictates motion of that segment.
• Inferior articular process is anterior & inferior (C-spine) and anterior & lateral (L-spine) to the superior articular process.
• Joint innervation is from dorsal rami of two adjacent nerve root levels.
• Hypertrophic changes in degenerative disease can cause/contribute to nerve root impingement.
Capsule Surrounds the articular pro- Weak structure, adds little support. May hypertrophy in degen-
cesses erative joints and narrow neural foramen.
Meniscus/disc Within joint b/w processes Can be injured or degenerate and be source of pain
INTERVERTEBRAL DISCS
Stabilize and maintain spine by anchoring adjacent vertebral bodies. Allow flexibility and absorb/distribute energy.
• The discs make up 25% of the spine height. Disc degeneration with age results in loss of spinal column height.
Annulus fibrosus Strong attachments to end • Two layers: 1. outer annulus: dense fibers (type 1 collagen);
plates of adjacent vertebral 2. inner annulus: fibrocartilage, looser type 2 collagen fibers
bodies (via “outer annulus”)
• Fibers are obliquely oriented and resist tensile loads
• Outer layer innervated, tears can cause back pain (esp. LBP)
Nucleus pulposus Contained within the annulus • Gelatinous mass of water, proteoglycans, & type 2 collagen
• Resists compressive loads (highest when sitting forward)
• Water & proteoglycan content decrease with advancing age
• Can herniate out of annulus & compress nerve root (L4-5 #1)
46 NETTER’S CONCISE ORTHOPAEDIC ANATOMY
JOINTS • Spine 2
Anterior longitudinal Transverse costal facet (for tubercle
ligament of rib of same number as vertebra)
Inferior costal
facet (for head of Lateral costotransverse ligament
rib one number
higher) Intertransverse ligament
Interarticular
ligament of Superior Superior articular
head of rib costotransverse facet of rib head
Superior costal ligament
facet (for head of Intraarticular ligament
rib of same Radiate
number) ligament Synovial
of head cavities
Radiate of rib
ligament of
head of rib Superior
costotransverse
Left lateral view ligament (cut)
Articular cartilage on dens for median Atlas (C1) Costotransverse ligament
atlantoaxial joint complex Axis (C2) Lateral costotransverse ligament
Transverse section: superior view
Lateral atlantoaxial joint
Facet (zygapophyseal)
joint between C2 and
C3
Foramen transversarium
Uncinate processes
Annulus fibrosus
Uncovertebral joints (clefts) of Luschka
LIGAMENT ATTACHMENTS COMMENTS
UNCOVERTEBRAL JOINTS
• “Joints of Luschka”: articulation in cervical spine b/w the uncinate process on the concave superior end plates of the in-
ferior vertebral body & the articulating portion of the convex inferior end plate of the superior adjacent vertebral body.
• Articular cartilage at this joint can degenerate and contribute to cervical spondylosis.
COSTOVERTEBRAL JOINTS
Articulation between the head of the rib and the thoracic vertebra (body and transverse process)
Capsule Surround head of rib/joint Weak support of joint
Intraarticular Head of rib to body/disc Deep to radiate
Radiate Head of rib to bodies & disc Fan shaped, reinforces joint anteriorly
Costotransverse Transverse process to rib Superior costotransverse attaches to TP of superior vertebrae
OTHER
Neural foramen: Boundaries: superior & inferior: pedicles; anterior: body & disc (uncinate process in C-spine); poste-
rior: facet joint & capsule. Osteophytes, discs, facet hypertrophy, and ligamentum flavum can all narow foramen.
NETTER’S CONCISE ORTHOPAEDIC ANATOMY 47
2 Spine • HISTORY Radicular symptons
Lower back Paresthesias and/or
pain radiating pain
Head-on collision with stationary object or oncoming vehicle may, if seat belts not used, drive
forehead against windshield. This sharply hyperextends neck, resulting in dislocation with
or without fracture of cervical vertebrae
QUESTION ANSWER CLINICAL APPLICATION
1. Age
Young Disc injuries, spondylolisthesis
2. Pain Middle age Sprain/strain, nucleus pulposis/disc (HNP), degenerative
a. Character disc disease (DDD)
b. Location Elderly Spinal stenosis, herniated disc, DDD, spondylosis
c. Occurrence Radiating (shooting) Radiculopathy (herniated nucleus pulposis [HNP])
d. Alleviating Diffuse, dull, non radiating Cervical or lumbar strain
e. Exacerbating Unilateral vs bilateral Unilateral: herniated nucleus pulposis; Bilateral: systemic
3. Trauma or metabolic disease, space-occupying lesion
4. Activity Neck Cervical spondylosis, neck sprain or muscle strain
5. Neurologic Arms (ϩ/Ϫ radiating) Cervical spondylosis (ϩ/Ϫ myelopathy), HNP
symptoms Lower back DDD, back sprain/muscle strain, spondylolisthesis
Legs (ϩ/Ϫ radiating) Herniated nucleus pulposis, spinal stenosis
6. Systemic Night pain Infection, tumor
complaints With activity Usually mechanical etiology
Arms elevated Herniated cervical disc (HNP)
Sit down Spinal stenosis (stenosis relieved)
Back extension Spinal stenosis (going down stairs), DJD/facet hypertrophy
MVA (seatbelt?) Cervical strain (whiplash), cervical fractures, ligamentous injury
Sports (stretching injury) “Burners/stingers”(esp. in football), fractures
Pain, numbness, tingling Radiculopathy, neuropathy, cauda equina syndrome
Spasticity, clumsiness Myelopathy
Bowel/bladder symptoms Cauda equina syndrome
Fever, weight loss, night Infection, tumor
sweats
48 NETTER’S CONCISE ORTHOPAEDIC ANATOMY
Inspection PHYSICAL EXAMINATION • Spine 2
Range of motion
Scoliosis
Gauging Spinal column
trunk movements:
alignment
with plumb Flexion
line Extension
Side bending
Malalignment Rotation
of spine
Palpate for: Palpation Palpate for local
Muscle spasm tenderness or spasm
Trigger zones
Myofascial nodes
Sciatic nerve tenderness
Compress iliac crests
for sacroiliac tenderness
EXAM TECHNIQUE CLINICAL APPLICATION
Gait INSPECTION
Alignment
Posture Leaning forward Spinal stenosis
Skin Wide-based Myelopathy
Bony structures Malalignment Dislocation, scoliosis, lordosis, kyphosis
Soft tissues
Head tilted Dislocation, spasm, spondylosis, torticollis
Flexion/extension: cervical Pelvis tilted Loss of lordosis: spasm
Flexion/extension: lumbar
Lateral flexion: cervical Disrobe patient Cafe-au-lait spots, growths: possibly neurofibromatosis
Lateral flexion: lumbar Port wine spots, soft masses: possibly spina bifida
Rotation: cervical
Rotation: lumbar PALPATION
Spinous processes Focal/point tenderness: fracture; step-off: dislocation/
spondylolisthesis
Cervical facet joints Tenderness: osteoarthritis, dislocation
Coccyx, via rectal exam Tenderness: fracture or contusion
Paraspinal muscles Diffuse tenderness: sprain/muscle strain; trigger point:
spasm
RANGE OF MOTION
Chin to chest/occiput back Normal: Flexion: chin within 3-4cm of chest; ext. 70°
Touch toes with legs straight Normal: 45-60° in flexion, 20-30° in extension
Ear to shoulder Normal: 30-40° in each direction
Bend to each side Normal: 10-20° in each direction
Stabilize shoulders: rotate Normal: 75° in each direction
Stabilize hip: rotate Normal: 5-15° in each direction
NETTER’S CONCISE ORTHOPAEDIC ANATOMY 49
2 Spine • PHYSICAL EXAMINATION
Level Motor Reflex Sensory
C5 Deltoid Biceps brachii
Biceps brachii
C6 Brachioradialis
Triceps brachii
Triceps brachii
C7
Interossei None
C8
EXAM TECHNIQUE CLINICAL APPLICATION
C5 NEUROVASCULAR
C6
C7 Lateral shoulder Cervical
C8 Thumb
T1 Middle finger Sensory
Ring & small fingers
C5 Ulnar forearm & hand Deficit indicates a corresponding cervical root compression/lesion
C6 Deficit indicates a corresponding cervical root compression/lesion
C7 Deltoid: resisted abduction Deficit indicates a corresponding cervical root compression/lesion
C8 Biceps: resisted elbow flexion Deficit indicates a corresponding cervical root compression/lesion
T1 Triceps: resisted elbow ext. Deficit indicates a corresponding cervical root compression/lesion
Intrinsics: resisted finger
C5 abduction Motor
C6
C7 Biceps Weakness indicates corresponding cervical root compression/lesion
Inverted radial Brachioradialis (BR) Weakness indicates corresponding cervical root compression/lesion
Triceps Weakness indicates corresponding cervical root compression/lesion
Hoffman’s Tap BR tendon in distal Weakness indicates corresponding cervical root compression/lesion
forearm Weakness indicates corresponding cervical root compression/lesion
Flick MF DIPJ into flexion
Reflexes
Brachial, radial, ulnar
Hypoactive/absent indicates C5 radiculopathy
Hypoactive/absent indicates C6 radiculopathy
Hypoactive/absent indicates C7 radiculopathy
Hypoactive brachioradialis & hyperactive finger flexion: myelopathy
Pathologic if thumb IPJ flexes: myelopathy
Pulses
Diminished/absent ϭ vascular injury or compromise
50 NETTER’S CONCISE ORTHOPAEDIC ANATOMY
PHYSICAL EXAMINATION • Spine 2
Level Motor Reflex Sensory
L4 Quadriceps
Patella tendon Medial
L5 Tibialis (”knee jerk”) calf/ankle
anterior
Dorsal foot
L4 and 1st web
space
Extensor
hallucis
longus
None
S1 Plantar and
Achilles tendon lateral foot
(“ankle jerk”)
S1 Gastroc-
nemius
EXAM TECHNIQUE CLINICAL APPLICATION
L3 NEUROVASCULAR
L4
L5 Anterior & medial thigh Lumbar
S1 Medial leg & ankle
S2-4 Dorsal foot & 1st web space Sensory
Lateral & plantar foot
L3-4 Perianal sensation Deficit indicates corresponding lumbar root compression/lesion
L4 Deficit indicates corresponding lumbar root compression/lesion
L5 Quadriceps: knee extension Deficit indicates corresponding lumbar root compression/lesion
S1 Tibialis anterior: ankle DF Deficit indicates corresponding lumbar root compression/lesion
S2-4 Extensor hallucis longus: toe DF Deficit indicates corresponding lumbar root compression/lesion
Gastrocnemius: ankle PF
L4 Anal sphincter: anal squeeze Motor
S1
S2-3 Patellar tendon (“knee jerk”) Weakness indicates corresponding lumbar root compression/lesion
Babinski Achilles tendon (“ankle jerk”) Weakness indicates corresponding lumbar root compression/lesion
Ankle clonus Bulbocavernosus Weakness indicates corresponding lumbar root compression/lesion
Run stick along plantar foot Weakness indicates corresponding lumbar root compression/lesion
Rapidly flex & extend ankle Weakness indicates corresponding lumbar root compression/lesion
Posterior tibial, dorsalis pedis Reflexes
Hypoactive/absent indicates L4 radiculopathy
Hypoactive/absent indicates S1 radiculopathy
Hypoactive/absent indicates S2-3 radiculopathy or spinal shock
Upgoing great toe: upper motor neuron/myelopathy
Multiple beats of clonus: upper motor neuron/myelopathy
Pulses
Diminished/absent ϭ vascular injury or compromise
NETTER’S CONCISE ORTHOPAEDIC ANATOMY 51
2 Spine • PHYSICAL EXAMINATION Spurling maneuver
Forward bending test Hyperextension and flexion of
neck ipsilateral to the side of
Estimation of rib hump lesion cause radicular pain
and evaluation of curve in neck and down the
unwinding as patient turns affected arm
trunk from side
to side
Straight leg test
Passively flex hip.
Stop when pain occurs.
Lower leg until pain re-
solves, then dorsiflex foot.
Extend knee, hip relaxed
EXAM TECHNIQUE CLINICAL APPLICATION
Spurling SPECIAL TESTS
Distraction
Kernig Cervical
Brudzinski
Axial load, then laterally flex & rotate Radiating pain indicates nerve root compression
Straight leg neck
Straight leg 90/90
Bowstring Upward distracting force Relief of symptoms indicates foraminal compression of
Sitting root (flip nerve root
sign) Supine: flex neck Pain in or radiating to legs indicates meningeal irritation/
Forward bending infection
Hoover
Waddell signs Supine: flex neck, hip flex Pain reduction with knee flexion indicates meningeal
irritation
Lumbar
Flex hip to pain, dorsiflex foot Symptoms reproduced (pain radiating below knee) indica-
tive of radiculopathy
Supine: flex hip & knee 90°, extend Ͼ20° of flexion ϭ tight hamstrings: source of pain
knee
Raise leg, flex knee, popliteal press Radicular pain with popliteal pressure indicates sciatic
nerve cause
Seated: distract patient, passively Patient with sciatic pain will arch/flip backward when
extend knee knee extended
Standing, bend at waist Asymmetry of back (scapula/ribs) is indicative of scoliosis
Supine: hands under heels, patient Pressure should be felt under opposite heel. No pressure
then raises one leg indicates lack of effort, not true weakness
Presence indicates nonorganic pathology: 1. Exaggerated response/overreaction, 2. Pain to light
touch, 3. Nonanatomic pain localization, 4. Negative flip sign with positive straight leg test
52 NETTER’S CONCISE ORTHOPAEDIC ANATOMY
MUSCLES • Spine 2
Superficial (investing) layer of deep cervical fascia Platysma muscle
Sternohyoid muscle
Infrahyoid fascia Trachea
Pretracheal (visceral) fascia Sternothyroid muscle
Thyroid gland
Buccopharyngeal Esophagus
(visceral) fascia Omohyoid muscle
Carotid sheath Sternocleidomastoid
muscle
Subcutaneous tissue
Recurrent laryngeal
Superficial nerve
(investing) layer
of deep cervical Common carotid artery
fascia roofing Internal jugular vein
posterior triangle Vagus nerve (X)
Phrenic nerve
Fat in Anterior scalene muscle
posterior Sympathetic trunk
triangle
Spinal nerve
Prevertebral layer
of (deep) Middle and posterior
cervical fascia scalene muscles
Longus colli muscle
Alar fascia Retropharyngeal Subcutaneous Levator scapulae muscle
Cross section space tissue Trapezius muscle
Deep cervical muscles
Cervical vertebra (C7)
Sagittal section Mandible
Geniohyoid muscle
Pharynx Geniohyoid fascia
Buccopharyngeal (visceral) Investing layer of (deep)
fascia cervical fascia
Retropharyngeal Fascia of infrahyoid muscles
space Pretracheal (visceral) fascia
Alar fascia Thyroid gland
Prevertebral fascia Subcutaneous tissue
Trachea Suprasternal space (of Burns)
Esophagus Manubrium of sternum
Aorta
Pericardium
LAYER CONTENTS COMMENT
Platysma FASCIA LAYERS
Deep cervical fascia
Pretracheal fascia Thin superficial muscle Highly vascular, must be split to access cervical spine
Carotid sheath
Invests sternocleidomastoid Incised in anterior cervical approach
Prevertebral fascia
Invests thyroid, trachea Incised off of carotid sheath to access cervical spine
Carotid artery, internal jugular vein, Left intact and used to retract structures laterally unless
vagus nerve (CN 10) access to contents of sheath is needed
Covers A.L.L. & longus colli Deepest fascial layer, incised to access vertebral body
and disc
NETTER’S CONCISE ORTHOPAEDIC ANATOMY 53
2 Spine • MUSCLES
Hyoid bone Digastric muscle (anterior belly)
Mylohyoid muscle
Thyrohyoid membrane Hyoglossus muscle
External carotid artery Stylohyoid muscle
Digastric muscle
Internal jugular vein (posterior belly)
Thyrohyoid muscle Fibrous loop for inter-
mediate digastric tendon
Thyroid cartilage
Omohyoid muscle Sternohyoid and omohyoid
(superior belly) muscles (cut)
Sternohyoid muscle
Thyrohyoid muscle
Median cricothyroid Oblique line of
ligament thyroid cartilage
Cricoid cartilage Cricothyroid muscle
Scalene
muscles Sternothyroid muscle
Trapezius Omohyoid muscle
muscle (superior belly) (cut)
Omohyoid muscle Thyroid gland
(inferior belly) Sternohyoid muscle (cut)
Clavicle
Trachea
MUSCLE ORIGIN INSERTION ACTION NERVE
Platysma
Sternocleidomastoid ANTERIOR NECK CN 7
Digastric Fascia: deltoid/pecto- Mandible; skin Depress jaw CN 11
ralis major
Mylohyoid Anterior: mylohy-
Stylohyoid Manubrium & clavicle Mastoid process Turn head opposite side oid (CN 5)
Geniohyoid Post: facial (CN 7)
ANTERIOR CERVICAL TRIANGLE Mylohyoid (CN 5)
Sternohyoid Facial nerve (CN 7)
Omohyoid Suprahyoid Muscles C1 via CN 12
Thyrohyoid
Sternothyroid Anterior: mandible Hyoid body Elevate hyoid, depress Ansa cervicalis
Posterior: mastoid mandible Ansa cervicalis
notch
C1 via CN 12
Mandible Raphe on hyoid Same as above Ansa cervicalis
(C1-3)
Styloid process Body of hyoid Elevate hyoid
Genial tubercle of Body of hyoid Elevate hyoid
mandible
Manubrium & clavicle Infrahyoid Muscles Depress hyoid
Superficial
Body of hyoid
Suprascapular notch Body of hyoid Depress hyoid
Thyroid cartilage Deep Depress hyoid/larynx
Greater horn of hyoid
Manubrium Thyroid cartilage Depress/retract hyoid/
larynx
54 NETTER’S CONCISE ORTHOPAEDIC ANATOMY
Epicranial aponeurosis MUSCLES • Spine 2
(galea aponeurotica)
Occipital belly (occipitalis) of Rectus capitis posterior minor muscle
occipitofrontalis muscle Rectus capitis posterior major muscle
Semispinalis capitis muscle
Greater occipital nerve (cut and reflected)
(dorsal ramus of C2 Vertebral artery
spinal nerve) (atlantic part)
Obliquus capitis
Occipital artery superior muscle
Suboccipital nerve
3rd (least) occipital nerve (dorsal ramus of C1
(dorsal ramus of C3 spinal nerve)
spinal nerve) Posterior arch of
atlas (C1 vertebra)
Semispinalis capitis
and splenius capitis Occipital artery
muscles in posterior
triangle of neck Obliquus capitis
inferior muscle
Posterior auricular artery
Great auricular nerve Greater occipital
(cervical plexus C2, 3) nerve (dorsal ramus
Lesser occipital nerve of C2 spinal nerve)
(cervical plexus C2, 3)
Splenius capitis muscle
Sternocleidomastoid muscle (cut and reflected)
Trapezius muscle 3rd (least) occipital nerve
(dorsal ramus of C3
Posterior cutaneous branches spinal nerve)
of dorsal rami of C4, 5, 6
spinal nerves Longissimus capitis muscle
Splenius cervicis muscle
Semispinalis cervicis muscle
Semispinalis capitis muscle (cut)
Splenius capitis muscle (cut)
MUSCLE ORIGIN INSERTION ACTION NERVE
POSTERIOR NECK Laterally flexes neck C5-C8 nerve roots
and elevates 1st or
Scalene muscles C3-6 transverse process 1st rib 2nd rib Suboccipital nerve
Anterior C2-7 transverse process 1st rib Suboccipital nerve
Middle C4-6 transverse process 2nd rib Extend, rotate, laterally Suboccipital nerve
Posterior flex head Suboccipital nerve
Extend, laterally flex
Suboccipital Triangle
Extend, rotate, laterally
Rectus capitis posterior Spine of axis Inferior nuchal flex
major line Extend, laterally rotate
Rectus capitis posterior Posterior tubercle of Occipital bone
minor atlas
Obliquus capitis Atlas transverse process Occipital bone
superior
Obliquus capitis inferior Spine of axis Atlas transverse
process
Semispinalis, see page 58; Splenius, see page 57.
NETTER’S CONCISE ORTHOPAEDIC ANATOMY 55
2 Spine • MUSCLES Semispinalis capitis muscle
Superior nuchal line of skull Splenius capitis muscle
Spinous process of C2 vertebra Spinous process of C7 vertebra
Sternocleidomastoid muscle Splenius cervicis muscle
Posterior triangle of neck Levator scapulae muscle
Trapezius muscle
Rhomboid minor muscle (cut)
Spine of scapula
Supraspinatus
Deltoid muscle muscle
Infraspinatus
fascia Serratus
posterior
Teres minor superior muscle
muscle
Rhomboid
Teres major major muscle
muscle (cut)
Latissimus Infraspinatus
dorsi muscle fascia (over
infraspinatus
Spinous process muscle)
of T12 vertebra Teres minor
and major
Thoracolumbar fascia muscles
External Latissimus dorsi muscle (cut)
oblique muscle
Serratus anterior muscle
Internal oblique
muscle in lumbar triangle Serratus posterior inferior
(Petit) muscle
Iliac crest 12th rib
Gluteal aponeurosis Erector spinae muscle
(over gluteus medius muscle)
External
oblique muscle
Internal
oblique muscle
MUSCLE ORIGIN INSERTION ACTION NERVE
Trapezius Spinous process SUPERFICIAL (EXTRINSIC) CN 11
C7-T12 Thoracodorsal
Latissimus dorsi Clavicle; scapula Rotate scapula Dorsal scapular, C3,
Spinous process (spine, acromion)
Levator scapulae T6-S5 C4 (dorsal rami)
Humerus Extend, adduct, IR arm Dorsal scapular
Rhomboid minor Transverse process Dorsal scapular
C1-4 Scapula (medial) Elevate scapula Intercostal n. (T1-4)
Rhomboid major Intercostal n. (T9-12)
Spinous process Scapula (spine) Adduct scapula
Serratus posterior C7-T1
superior Scapula (medial border) Adduct scapula
Serratus posterior Spinous process
inferior T2-T5 Ribs 2-5 (upper border) Elevate ribs
Spinous process Ribs 9-12 (lower Depress ribs
C7-T3 border)
Spinous process
T11-L3
56 NETTER’S CONCISE ORTHOPAEDIC ANATOMY
Superior nuchal line of skull MUSCLES • Spine 2
Posterior tubercle of atlas (C1)
Rectus capitis posterior minor muscle
Longissimus capitis muscle Obliquus capitis superior muscle
Semispinalis capitis muscle Rectus capitis posterior major muscle
Obliquus capitis inferior muscle
Splenius capitis and Longissimus capitis muscle
splenius cervicis muscles Semispinalis capitis muscle (cut)
Serratus posterior superior muscle
Spinalis cervicis muscle
Iliocostalis muscle Spinous process of C7 vertebra
Longissimus cervicis muscle
Erector Iliocostalis cervicis muscle
spinae Longissimus muscle
muscle Iliocostalis thoracis muscle
Hook
Spinalis muscle Spinalis thoracis muscle
Longissimus thoracis muscle
Serratus posterior Iliocostalis lumborum muscle
inferior muscle Spinous process of T12 vertebra
Transversus abdominis
Tendon of origin of muscle and tendon
transversus abdominis muscle of origin
Thoracolumbar fascia
Internal oblique (cut edge)
muscle
External oblique
muscle (cut)
Iliac crest
MUSCLE ORIGIN INSERTION ACTION NERVE
DEEP (INTRINSIC) Dorsal rami of inferior
cervical nerves
Superficial Layer: Spinotransverse Group
Dorsal rami of spinal
Splenius capitis Ligamentum nuchae Mastoid & nuchal line Both: laterally flex & nerves
Splenius cervicis Spinous process T1-6 Transverse process rotate neck to same
C1-4 side
Intermediate Layer: Sacrospinalis Group (Erector Spinae)
Iliocostalis Common origin: sa- Ribs Laterally flex, extend,
Longissimus crum, iliac crest, and T & C spinous process, and rotate head (to
lumbar spinous pro- mastoid process same side) and ver-
Spinalis cess T-spine: spinous tebral column
process
All have three parts: thoracis, cervicis, and capitus
NETTER’S CONCISE ORTHOPAEDIC ANATOMY 57
2 Spine • MUSCLES Rectus capitis posterior minor muscle
Obliquus capitis superior muscle
Superior nuchal line of skull Rectus capitis posterior major muscle
Mastoid process Transverse process of atlas (C1)
Obliquus capitis inferior muscle
Posterior tubercle of atlas Longus
(C1 vertebra) Brevis Rotatores cervicis muscles
Interspinalis cervicis muscle
Spinous process of axis
(C2 vertebra) Levator costae muscle
Semispinalis capitis muscle Longus Rotatores
Brevis thoracis muscles
Spinous process Brevis Levatores
of C7 vertebra Longus costarum muscles
External intercostal muscles Interspinalis lumborum muscle
Lateral intertransversarius muscle
Semispinalis thoracis muscle Quadratus lumborum muscle
Multifidi muscles Iliac crest
Multifidi muscles (cut)
Thoracolumbar fascia
(anterior layer)
Thoracolumbar fascia
(posterior layer) (cut)
Transversus abdominis muscle
and tendon of origin
Multifidi muscles
Erector spinae muscle (cut)
MUSCLE ORIGIN INSERTION ACTION NERVE
Semispinalis capitus DEEP (INTRINSIC) Dorsal primary rami
Semispinalis (C&T) Dorsal primary rami
Multifidus (C2-S4) Deep Layers: Transversospinalis Group Dorsal primary rami
Rotatores Dorsal primary rami
Levator costarum Transverse process Nuchal ridge Extend head Dorsal primary rami
Interspinales T1-6 Dorsal primary rami
Intertransversarii Dorsal primary rami
Transverse process Spinous process Extend, rotate opposite
side
Transverse process Spinous process Flex laterally, rotate
opposite
Transverse process Spinous process ϩ1 Rotate superior verte-
brae opposite
Transverse process Brevis: rib Ϫ1 Elevate rib during
Longus: rib Ϫ2 inspiration
Spinous process Spinous process ϩ1 Extend column
Tranverse process Transverse process ϩ1 Laterally flex column
58 NETTER’S CONCISE ORTHOPAEDIC ANATOMY
NERVES • Spine 2
Cervical Spine Injury: Incomplete Spinal Syndromes
Spinal cord orientation
Posterior columns (position sense)
Lower limb
Trunk Lateral corticospinal tract (motor)
Upper limb
Lower limb Lateral spinothalamic tract
Trunk (pain and temperature); fibers
Upper limb decussate before ascending
Anterior spinal artery
Ventral root of spinal n.
Dorsal root of spinal n.
Spinal sensory (dorsal root) ganglion
White and gray rami
communicantes to and
from sympathetic trunk
Ventral ramus of spinal n.
Dorsal ramus of spinal n.
Dura mater
Arachnoid mater
Subarachnoid space Filaments of dorsal root
Pia mater overlying
spinal cord
TRACT FUNCTION COMMENT
SPINAL CORD
• Runs from brain stem to conus medullaris (termination at L1) within the spinal canal where it is protected.
• Terminale filum and cauda equina (lumbar and sacral nerve roots) continue in the spinal canal.
• It has a layered covering (membranes): dura mater, arachnoid mater, pia mater.
• It is made up of multiple ascending (sensory) and descending (motor) tracts and columns.
• It is wider in the cervical and lumbar spines, where the roots form plexus to innervate the upper and lower extremities.
• Paired (R & L) nerve roots emerge from each level. Nerve roots made up of ventral (motor) and dorsal (sensory) roots.
• Injury can be either complete or incomplete (see page 42 for spinal cord injuries).
Descending (Motor)
Anterior corticospinal Innervates motor neurons—voluntary motor Minor motor pathway, injured in anterior cord
syndrome
Lateral corticospinal Innervates motor neurons—voluntary motor Major motor pathway, injured in Brown-
Sequard syndrome
Ascending (Sensory)
Anterior spinothalamic Light touch sensation Injured in anterior cord syndrome
Lateral spinothalamic Pain and temperature sensation Injured in Brown-Sequard syndrome
Dorsal columns Proprioception and vibratory sensation Usually preserved, injured in posterior cord
syndrome
NETTER’S CONCISE ORTHOPAEDIC ANATOMY 59
2 Spine • NERVES
Base C1 C1 C1 spinal nerve exits L4
of skull above C1 vertebra
Cervical C2
enlargement C2 C3 L4
C3 C4
Lumbar C4 L5
enlargement C5 L5
C5 C6 C8 spinal nerve
Filum
terminale C6 C7 exits below
internum C7 C8 C7 vertebra
(there are 8 cervical S1
Filum T1 nerves but only
terminale T1 7 cervical vertebrae)
externum
(coccygeal T2
ligament) T3 T2
T3 S2
T4
T5 T4 Conus medullaris Disc protrusion at disc level L4–5 affects L5
T6 T5 (termination of spinal nerve, not L4 spinal nerve.
spinal cord)
T6 Lumbar Vertebra
T7
T7
T8 Dura mater
T8 Sympathetic Arachnoid mater
ganglion
T9
T9
T10 T10 Gray ramus Ventral root
communicans Spinal nerve
T11 T11
Fat in Ventral ramus
T12 epidural (contributes to
T12 space lumbar plexus)
L1
L1 Dorsal and ventral Dorsal
L2 roots of lumbar and ramus
sacral spinal nerves Spinal sensory
L2 forming cauda equina (dorsal root) ganglion
L3 Dorsal root
L3
Conus medullaris
L4
L4 Exiting spinal
nerve roots
Cauda equina
L5
L5
Sacrum
S1 Vertebral Terminal
S2 body spinal cord
and cauda
S3 Termination of Lamina equina
within
S4 dural sac Spinous thecal sac
S5 process
Coccygeal nerve Cervical nerves
Thoracic nerves MRI lumbar spine, axial
Coccyx Lumbar nerves
Sacral and coccygeal nerves
SPINAL NERVES
• Spinal nerves are made up of a ventral (motor) root and a dorsal (sensory) root. There are 31 pairs (L & R).
• Cell bodies for sensory nerves are in dorsal root ganglia. Motor nerve cell bodies are in ventral horn of spinal cord.
• Roots exit spinal column via the intervertebral (neural) foramen (under pedicle); (C1-7 exit above their vertebrae,
C8-L5 exit below their vertebrae [C7 exits above and C8 exits below C7 vertebra]).
• They can be compressed by herniated discs, osteophytes, and hypertrophied soft tissues (ligamentum flavum,
facet capsule). In lumbar spine the traversing nerve is usually affected, and exiting root is not (except in far lateral
compression).
• The lumbar and sacral nerves form the cauda equina (“horse’s tail”) in the spinal canal before exiting.
• Spinal nerve divides into dorsal and ventral rami. Dorsal rami innervate local structures (neck and back musculature,
overlying skin, facet capsules, etc). Ventral rami contribute to plexus (e.g., cervical, brachial, lumbosacral) and become
peripheral nerves to the extremities.
• Ventral rami of spinal nerve commonly referred to as a spinal “roots.” The roots combine to form the various plexus.
60 NETTER’S CONCISE ORTHOPAEDIC ANATOMY
NERVES • Spine 2
Schematic demarcation of dermatomes C2
(according to Keegan and Garrett)
shown as distinct segments. There is C3
actually considerable overlap between C4
any two adjacent dermatomes. C5
C6
C2
C6 C6 C7 T1
C3 T1 C7 C8 T2
C4 C8 T3
C5 C7 C8 T4
C5 T5
T1 C6 T6
T2 C8 T7
T3 T8
T4 C7 T9
T5 T10
T6 T11
T7 T12
T8 L1
T9 L2
L3
T10 L4
L5
T11 S1
S2
T12
S3
L1 S4
S2, 3 S5 S1
L2
L5 S2
L3
L4 L1
L2
L3
L5 S1S2
S1 L4
L5 S1
L4 L5
L4
Levels of principal dermatomes T10 Level of umbilicus
L1 Inguinal or groin regions
C5 Clavicles L1, 2, 3, 4 Anterior and inner surfaces of lower limbs
C5, 6, 7 Lateral parts of upper limbs L4, 5, S1 Foot
C8, T1 Medial sides of upper limbs L4 Medial side of great toe
C6 Thumb S1, 2, L5 Posterior and outer surfaces of lower limbs
C6, 7, 8 Hand S1 Lateral margin of foot and little toe
C8 Ring and little fingers S2, 3, 4 Perineum
T4 Level of nipples
NETTER’S CONCISE ORTHOPAEDIC ANATOMY 61
2 Spine • NERVES
C6 C2
C3
C7 C6 Anterior view
C8 C4
C5 C5
C2 T1
C8 T1
C3 Posterior view C6
C4 C7
C5 C8
C6
C7
C8
T1
LEVEL MOTOR SENSORY REFLEX COMMENT
C1 Geniohyoid CERVICAL ROOTS Part of cervical plexus, contributes to
Thyrohyoid ansa cervicalis
C2 Rectus capitus None None
C3 Longus colli/capitis Muscle innervation via the dorsal rami
C4 Diaphragm Parietal scalp None Contributes to phrenic & dorsal
C5 Occipital scalp None
C6 Diaphragm scapular nerves
C7 Base of neck None Branches to phrenic and dorsal scap-
C8 Deltoid
T1 Lateral shoulder and arm Biceps ular nerves & levator scapula muscle
Biceps brachii Dorsal scapular n. branches from
ECRL, ECRB Lateral forearm and Brachioradialis C5 root
Triceps brachii thumb Triceps Most commonly compressed cervical
FCR, FCU None
FDS, FDP Posterior forearm, central None nerve root
hand, and middle finger Exits above C7 vertebra
Interosseous
Medial forearm, ulnar Exits below C7 vertebra
fingers
Only thoracic root in brachial plexus
Medial arm
62 NETTER’S CONCISE ORTHOPAEDIC ANATOMY
NERVES • Spine 2
Schematic T10 L1 T12
demarcation of T11 L2
dermatomes T12 L3
(according to L1 L4
Keegan and L5
Garrett) shown as S2 S1
distinct segments. L2 S3 S2
There is actually S3
considerable L3 S4 S2
overlap between Autonomous S5
any two adjacent L4 sensory zones Co
dermatomes. L3
L1
L4 S2 S1
L2
L3 L5
L5 L5 L5
S1
L4
S1
Anterior view Posterior view L4 L5 S1
Segmental innervation
of lower limb movements Knee
Extension
Hip L3, 4 L5, S1 Dorsiflexion
Flexion L4, 5 L5, S1
L4, 5 Inversion Eversion
Foot
L2, 3 L5, S1 S1, 2 Ankle
Flexion Extension Plantar flexion
LEVEL MOTOR SENSORY REFLEX COMMENT
L1 Transversus abdominis LUMBOSACRAL ROOTS Rarely injured nerve root
Internal oblique
L2 Psoas Inguinal region None Test with hip flexion
L3 Quadriceps L3 & L4 tested with quadriceps
L4 Tibialis anterior Upper thigh None Test with ankle dorsiflexion
L5 Extensor hallux longus Most commonly compressed lumbar
Anterior and medial thigh None root; test with hallux dorsiflexion
S1 Gastrocnemius Test with ankle plantar flexion/toe
Medial leg, ankle, foot Patellar walking
Test tone to evaluate for cauda equina
Dorsal/plantar foot, 1st Hamstring syndrome
web space, lateral leg
Lateral foot, posterior leg Achilles
S2-4 Sphincter Perianal sensation Anal wink
NETTER’S CONCISE ORTHOPAEDIC ANATOMY 63
2 Spine • NERVES
Parotid gland Great auricular nerve
Facial artery and vein Lesser occipital nerve
Submandibular gland Sternocleidomastoid muscle
(cut, turned up)
Mylohyoid muscle Stylohyoid muscle
Digastric muscle (posterior belly)
Hypoglossal nerve (XII) C2 spinal nerve (ventral ramus)
Accessory nerve (XI)
Digastric muscle C3 spinal nerve (ventral ramus)
(anterior belly) Levator scapulae muscle
Middle scalene muscle
Lingual artery Anterior scalene muscle
External carotid artery C5 spinal nerve (ventral ramus)
Internal carotid artery Transverse cervical artery
Phrenic nerve
Thyrohyoid muscle Omohyoid muscle
(inferior belly) (cut)
Superior thyroid artery Brachial plexus
Omohyoid muscle (superior belly) (cut) Dorsal scapular artery
Ansa cervicalis Superior root Suprascapular artery
Inferior root
Sternohyoid muscle
Sternothyroid muscle
Internal jugular vein
Common carotid artery
Inferior thyroid artery
Vagus nerve (X)
Vertebral artery
Thyrocervical trunk
Subclavian artery and vein Accessory nerve (XI)
Great auricular nerve
Cervical plexus: schema Hypoglossal nerve (XII) S Lesser occipital nerve
C1
(S = gray ramus from superior
cervical sympathetic ganglion) To rectus capitis lateralis,
longus capitis, and rectus
To geniohyoid muscle S C2 capitis anterior muscles
To thyrohyoid muscle
Communication to vagus nerve
Transverse cervical nerves S C3
S C4
To omohyoid muscle To longus capitis and
(superior belly) longus colli muscles
Ansa cervicalis Superior root
Inferior root
To sternothyroid muscle
To sternohyoid muscle
To omohyoid muscle (inferior belly)
Supraclavicular nerves Phrenic nerve To scalene and levator
scapulae muscles
CERVICAL PLEXUS
C1-C4 ventral rami (behind IJ and SCM)
Lesser Occipital Nerve (C2-3): arises from posterior bor- Supraclavicular (C2-3): splits into 3 branches: anterior,
der of sternocleidomastoid middle, posterior
Sensory: Superior region behind auricle Sensory: Over clavicle, outer trapezius and deltoid
Motor: None Motor: None
Great Auricular Nerve (C2-3): exits inferior to lesser oc- Ansa Cervicalis (C1-3): superior (C1-2) & inferior (C2-3)
cipital nerve, ascends on SCM roots form loop
Sensory: Over parotid gland and behind ear Sensory: None
Motor: None Motor: Omohyoid
Sternohyoid
Sternothyroid
Tranverse Cervical Nerve (C2-3): exits inferior to greater Phrenic Nerve (C3-5):On anterior scalene, into thorax be-
auricular nerve, then to anterior neck tween subclavian artery and vein
Sensory: Anterior triangle of the neck Sensory: Pericardium and mediastinal pleura
Motor: None Motor: Diaphragm
64 NETTER’S CONCISE ORTHOPAEDIC ANATOMY
Right anterior dissection ARTERIES • Spine 2
Internal jugular vein
Common carotid artery Thyroid gland (reflected)
Middle cervical sympathetic ganglion
Ascending cervical artery Vagus nerve (X)
Phrenic nerve Vertebral artery
Common carotid artery
Anterior scalene muscle Recurrent laryngeal nerve
Inferior thyroid artery Brachiocephalic trunk
Internal jugular vein (cut)
Superficial cervical artery
Dorsal scapular artery Right external carotid artery
Suprascapular artery Right internal carotid artery
Costocervical trunk
Ascending cervical artery
Thyrocervical trunk Inferior thyroid artery
Subclavian artery and vein Superficial cervical artery
Right oblique schematic view Right common carotid artery
Vertebral artery Thyrocervical trunk
Deep cervical artery (ascending to Right subclavian artery (1st part medial
anastomose with descending branch to, 2nd part posterior to, 3rd part lateral
of occipital artery) to anterior scalene muscle)
Superficial cervical artery Brachiocephalic trunk
Suprascapular artery
Costocervical trunk Aortic arch
Supreme (superior) Internal thoracic (mammary) artery
intercostal artery
1st, 2nd, and 3rd anterior intercostal arteries
Dorsal scapular artery Subscapular artery
Superior and inferior
transverse scapular ligaments
Acromion
Dorsal scapular artery
Suprascapular artery
Axillary artery
1st and 2nd posterior
intercostal arteries
Circumflex scapular
artery
Thoracodorsal artery
COURSE BRANCHES COMMENT/SUPPLY
SUBCLAVIAN ARTERY
Branches off aorta (L) or bra- Vertebral arteries (R & L) Main arterial supply to the cervical spine and cord
chiocephalic trunk (R) b/w an- Thyrocervical trunk Has 4 primary branches
terior and middle scalene Ascending cervical Runs with phrenic nerve on anterior scalene muscles
muscles Superficial cervical Crosses posterior triangle of neck (scalenes, etc)
Deep cervical Off costocervical trunk, anastomoses w/ occipital
artery
VERTEBRAL ARTERY
Enters foramen transversarium Anterior spinal artery Single midline artery supplies anterior 2⁄3 of spinal cord
from C6 through C1 then runs Posterior spinal arteries 2 paired arteries supply posterior 1⁄3 of spinal cord
in a groove on the atlas, then Anterior ascending Give primary supply to odontoid
to brain stem to form basilar Posterior ascending Give primary supply to odontoid
artery Ant. segmental medullary Contribute to anterior spinal artery
Post. segmental medullary Contribute to posterior spinal arteries
Injury or infarct of the anterior or posterior spinal arteries can result in an anterior/central or posterior cord syndrome.
NETTER’S CONCISE ORTHOPAEDIC ANATOMY 65
2 Spine • ARTERIES
Posterior spinal arteries
Anterior spinal artery
Anterior segmental
medullary artery
Anterior radicular artery
Posterior radicular artery
Branch to vertebral body
and dura mater
Spinal branch
Dorsal branch of posterior
intercostal artery
Posterior intercostal artery
Paravertebral anastomoses
Prevertebral anastomoses
Thoracic (descending) aorta
Section through thoracic level:
anterosuperior view
COURSE BRANCHES COMMENT/SUPPLY
INTERCOSTAL(THORACIC)/LUMBAR ARTERY
Paired arteries (R & L) branch off Ventral branch To vertebral bodies
aorta, run posterior along vertebral Dorsal branch To posterior elements and cord
bodies (between ribs in thoracic Spinal branch Supplies cord, nerve roots, and body
region) Major anterior segmental “Artery of Adamkiewicz”—single medullary artery
medullary (radicular) (usually left T10-T12) to ant. spinal artery is pri-
mary supply to thoracolumbar cord. Injury can
cause cord ischemia/paralysis.
SPINAL BRANCH
Branches off dorsal branch and en- Anterior radicular Runs on ventral root, anastomoses with anterior
ters intervertebral foramen Posterior radicular spinal artery
Runs on dorsal root, anastomoses with posterior
Postcentral branch spinal artery
Prelaminar branch Supplies vertebral body and dura
Supplies lamina/posterior elements
ANTERIOR SPINAL
Single midline artery supplies ante- Central (sulcal) branches Supplies central cord region
Supplies peripheral 2⁄3 of spinal cord
rior 2⁄3 of spinal cord Pial arterial plexus
POSTERIOR SPINAL
Paired (R & L) arteries supply poste- Supplied by posterior medullary/radicular arteries
rior 1⁄3 of spinal cord
66 NETTER’S CONCISE ORTHOPAEDIC ANATOMY
ARTERIES • Spine 2
Posterior cerebral artery Anterior view Cervical vertebrae Posterior view
Superior cerebellar artery Posterior inferior cerebellar artery
Thoracic
Basilar artery vertebrae Posterior spinal arteries
Anterior inferior
cerebellar artery Lumbar Vertebral artery
vertebrae
Posterior inferior Sacrum Posterior segmental
cerebellar artery medullary arteries
Anterior Deep cervical artery
spinal artery
Vertebral artery Ascending cervical artery
Anterior segmental
medullary arteries Subclavian artery
Ascending
cervical Posterior segmental
artery medullary arteries
Deep cervical
artery Posterior
intercostal arteries
Subclavian artery
Anterior segmental Posterior segmental
medullary artery medullary arteries
Posterior Anastomotic loops to
intercostal anterior spinal artery
artery Lumbar arteries
Pial plexus Lateral (or medial)
sacral arteries
Major anterior Note: All spinal nerve roots have
segmental medullary associated radicular or segmental
artery (artery of medullary arteries. Most roots
Adamkiewicz) have radicular arteries. Both types
of arteries run along roots, but
Posterior radicular arteries end before
intercostal reaching anterior or posterior
artery spinal arteries; larger segmental
medullary arteries continue on to
Anterior segmental supply a segment of these arteries.
medullary artery
Lumbar artery
Anastomotic loops to
posterior spinal arteries
Cauda equina arteries
Lateral (or medial)
sacral arteries
NETTER’S CONCISE ORTHOPAEDIC ANATOMY 67
2 Spine • DISORDERS
Spinal stenosis: Laminectomy
Lateral
recesses and
neuroforamina
opened
Laminectomy defect Postoperative view of decompressed vertebral canal
DESCRIPTION Hx & PE WORKUP TREATMENT
• Strain or spasm of cervical CERVICAL STRAIN • Rest, NSAIDs, physical
musculature therapy, usually 2-6wk
Hx: Pain (nonradiating) XR: C-spine series:
• Often from MVA (“whip- PE: Decreased ROM, muscle usually normal • Can consider limited soft
lash”) or overuse tenderness, normal neuro- MR: Usually not collar immobilization
logic exam needed
• #2 medical complaint in U.S. • “Red flags” indicate further
• Multiple etiologies: muscle LOW BACK PAIN workup: fever/chills, radicu-
lopathy, abnormal neuro-
strain, annular tear, early Hx: Pain (may radiate to XR: L-spine series: logic exam
spondylosis, or degenerative buttocks, not below knee) usually normal
disc disease PE: Limited ROM, muscle MR: Usually not • Rest, NSAIDs, physical
• Common workman (erector spinae) spasm/ needed therapy, usually 2-6wk
compensation/disability tenderness, normal neuro-
complaint logic exam; test for Wad- • Can consider lumbar brace
dell’s signs
• Narrowing of spinal • Activity modification,
canal results in cord/root SPINAL STENOSIS NSAIDs
compression
Hx: Pain, paresthesias XR: L-spine series: • PT— flexion exercises
• Causes: hypertrophy of relieved by sitting/forward DDD, facet DJD • Nerve root blocks/
facet capsule or ligamentum leaning (neurogenic CT: Canal narrowing
flavum, bulging disc, DDD/ claudication) MR: Evaluate cord/ epidural injection
osteophytes PE: Pain with back exten- root compression • Decompression (laminec-
sion, do good neurologic
exam tomy ϩ/Ϫ partial
facetectomy)
68 NETTER’S CONCISE ORTHOPAEDIC ANATOMY
DISORDERS • Spine 2
Cervical disc herniation
Laminae, spinous Herniated disc
process, and medial compressing
one third of facets nerve root
removed
Portion of
Disc herniation and lamina and
nerve compression facet removed
Lumbar disc herniation
Herniated
nucleus pulposus
Nerve root compressed
by herniated disc
Disc
material
removed
Disc material removed to
decompress nerve root
DESCRIPTION Hx & PE WORKUP TREATMENT
• Protrusion of nucleus pulpo- HERNIATED NUCLEUS PULPOSUS (HNP) • Rest, activity modification
sus through torn annulus • NSAIDs (limit narcotic use)
fibers Hx: Neck/back pain, ϩ/Ϫ XR: Often normal ϩ/Ϫ • Physical therapy
extremity (radiating) disc space narrowing • Epidural steroid injections
• Lumbar: L4-5 #1, traversing pain, paresthesias, and or spondylosis • Diskectomy ϩ/Ϫ fusion:
root affected except in far weakness MR: Best study to show
lateral herniation (exiting PE: Variable: decreased protruding disc and ؠFailed conservative
root) ROM, spinal tenderness nerve or cord com- treatment
Cervical: ϩ/Ϫ Spurling’s pression
• Thoracic: rare Lumbar: ϩ/Ϫ straight ؠProgressive neurologic
• Cervical: associated with deficit
leg raise
spondylosis Neuro: Radicular find- ؠCauda equina syndrome
• Can compress cord or roots ings
• Emergency surgical de-
• Compression of cauda CAUDA EQUINA SYNDROME compression-laminectomy/
equina diskectomy
Hx/PE: “Saddle” (perianal) XR: Normal or disc
• Usually from large midline anesthesia, lower space narrowing • (Prognosis is still guarded
disc herniation or extrusion extremity numbness/ MR: Study of choice: even with prompt diagno-
weakness, decreased compression of cauda sis and treatment.)
• Bowel & bladder dysfunction rectal tone equina
• Surgical emergency
NETTER’S CONCISE ORTHOPAEDIC ANATOMY 69
2 Spine • DISORDERS
Spine Involvement in Osteoarthritis
Atlas (C1)
Axis (C2)
C7
Extensive thinning of cervical discs and hyperextension deformity with
narrowing of intervertebral foramina. Lateral radiograph reveals similar changes
Degenerative Disc Disease
Radiograph of thoracic spine Degeneration of lumbar intervertebral discs and
shows narrowing of interverte- hypertrophic changes at vertebral margins with
bral spaces and spur formation spur formation. Osteophytic encroachment on
intervertebral foramina compresses spinal nerves
DESCRIPTION Hx & PE WORKUP TREATMENT
• Degenerative changes in CERVICAL SPONDYLOSIS • NSAIDs, activity modification
discs, facets, and unco- • Physical therapy, ϩ/Ϫ
vertebral joints Hx: Neck pain, ϩ/Ϫ UE XR: Loss of lordosis/ cer-
pain, paresthesias, vical straightening, loss traction
• C5-6 #1, C6-7 #2; and/or weakness of disc space • Epidural or facet injections
menϾwomen PE: Decreased ROM, ϩ MR: Shows disc degener- • Surgical
Spurling’s test, ϩ/Ϫ ation or herniation
• Causes axial/neck pain neurologic symptoms ؠAnterior diskectomy and
• Can result in cord or root fusion (ACDF)
DEGENERATIVE DISC DISEASE
compression: myelo/ra- ؠPosterior decompression/
diculopathy Hx: Back pain without XR: Can be normal or disc fusion
radiculopathy height loss
• Disc properties change PE: ϩ/Ϫ decreased MR: Low signal (black • Rest, activity modification,
(decr. H2O, proteins al- ROM or painful ROM, disc), decreased height NSAIDs, ϩ/Ϫ muscle
tered, etc) leads to decr. normal tension signs Discography: confirms relaxers
mechanical properties (straight leg/bowstring disc as pain source
tests) (used for preop. eval.) • Physical therapy: stretching,
• Ligaments/facets as- strengthening, weight control
sume greater load, can
be source of pain • Consider lumbar bracing
• Surgical: lumbar fusion or
• Natural process: unclear
why only some have pain disc replacement are options
70 NETTER’S CONCISE ORTHOPAEDIC ANATOMY
DISORDERS • Spine 2
Spondylolysis and Spondylolisthesis
Superior articular
process (ear of
Scottie dog)
Pedicle (eye)
Transverse process
(head)
Isthmus (neck)
Lamina and spinous
process (body)
Inferior articular process
(foreleg)
Opposite inferior
articular process
(hind leg)
Spondylolysis without spondylolisthesis. Posterolateral view demonstrates formation of
radiographic Scottie dog. On lateral radiograph, dog appears to be wearing a collar
Isthmic type spondylolisthesis. Anterior subluxation of L5 on sacrum due to fracture
of isthmus. Note that gap is wider and dog appears decapitated
DESCRIPTION Hx & PE WORKUP TREATMENT
• Defect or fracture of pars SPONDYLOLYSIS • Rest, activity modification
interarticularis (without slip) • Physical therapy: esp.
Hx: Insidious onset of XR: L-spine obliques
• Assoc. w/ hyperextension low back pain, worse “Scottie dog has a stretching, flexion exercises
sports (gymnasts, linemen) with activities collar/neck” • Lumbar brace
PE: Decreased lumbar CT: For subtle lesions • Surgery uncommon without
• Common in pediatrics lordosis, ϩ/Ϫ tight SPECT: Indicates if lesion
• L5 most common site hamstrings has healing capacity advanced spondylolisthesis
• Slippage of one vertebra on SPONDYLOLISTHESIS Low grade (1-2):
adjacent vertebrae • Rest, activity modification
Hx: Insidious onset of XR: Lateral view used to • Physical therapy
• Six types: low back pain, worse determine grade (% of • Lumbar bracing
ؠDysplastic (congenital) with activities ϩ/Ϫ vertebral body slipped)
ؠIsthmic (#1, L5-S1, radicular symptoms Grade 1: 0-25% High grade (3-4):
hyperextension) PE: Decreased ROM, Grade 2: 25-50% • Peds: prophylactic pos-
ؠDegenerative (elderly) often painful (esp. ex- Grade 3: 50-75% terolateral (PL) fusion
ؠTraumatic (acute pars fx) tension) ϩ/Ϫ sensory Grade 4: Ͼ75% • Adults: decompression
ؠPathologic or motor findings CT/SPECT: For subtle and PL fusion
ؠPost-surgical defects and healing
potential
NETTER’S CONCISE ORTHOPAEDIC ANATOMY 71
2 Spine • PEDIATRIC DISORDERS
Scoliosis
Measurement
of curvature T5 Upper end vertebrae for
thoracic curve (highest
(Cobb method) 6 vertebra with superior
border inclined toward
Vertebrae rotated 7 thoracic concavity) Torticollis (Wryneck)
with spinous 8
processes and Transitional vertebra
pedicles toward 67˚ 9 (lowest vertebra with
10 inferior border inclined
toward thoracic con-
concavity cavity and highest
vertebra with superior
Lower end 63˚ border inclined
vertebrae toward lumbar
for lumbar concavity)
curve (lowest
vertebra with
inferior border
inclined toward
lumbar concavity)
DESCRIPTION EVALUATION TREATMENT
• Incomplete spinal cord development MYELODYSPLASIA
(neural tube closure defect)
Hx: Can be diagnosed intrauterine • Must individualize for each
• 4 types depending on severity PE/XR: Based on type of defect: patient
• Associated w/elevated maternal AFP 1. Spina bifida
• Prenatal folic acid decreases incidence 2. Meningocele • Most need ambulation aids and/
• Associated with multiple deformities 3. Myelomeningocele or orthoses
4. Rachischisis
(spine, hips, knees, and feet) Symptoms/exam based on lowest • Muscle balancing (releases)
• Often associated with latex allergy functional level (intact L4 allows for • Individual deformities
ambulation)
• Lateral bending & rotation of the spine ؠScoliosis: most need fusion
• Types: ؠHips: keep them contained
ؠFeet: release or arthrodesis
ؠI. Congenital (abnormal vertebrae)
ؠII. Idiopathic: #1, often ϩfam hx; SCOLIOSIS
ؠInfantile: Ͻ3y.o., MϾF; Hx: Patient or parents may notice • School screening is effective
ؠJuvenile: 3-10y.o.; asymmetry of back; found on • Congenital: progression & need
ؠAdolescent: #1, FϾM, RϾL; school screening; ϩ/Ϫ pain; neuro
ؠIII. Neuromuscular: associated with sx rare for surgery depend on severity/
neuromuscular disease PE: Gross or subtle spinal deformity, type
• Curve progression evaluated by: ϩ forward bending test; neurologic • Idiopathic: depends on curve &
ؠCurve magnitude: x-ray/Cobb angle findings rare (increased with left- age
ؠSkeletal maturity: use Risser stage sided curves) ؠϽ25°: observation
• Classifications: King & Moe, Lenke XR: Full length spinal films: use ؠ25-40°: bracing
Cobb technique to determine ؠϾ40°: spinal fusion
• Head tilted, chin rotated opposite side angle • Juvenile type often needs fusion
• Sternocleidomastoid (SCM) contracture Bending films used to determine • Neuromuscular: often require
• Etiology unknown flexibility of the curve/deformity longer fusions, both anterior &
• Associated with intrauterine position posterior
• Associated with other disorders
TORTICOLLIS
Hx: Parents notice deformity, ϩ/Ϫ • Rule out any associated disorders
lump in the neck (on sternocleido- • Physical therapy/stretching (SCM)
mastoid) • Helmet may be needed for
PE: Head tilted/rotated, ϩ/Ϫ SCM
lump. ϩ/Ϫ cranial and/or facial cranium
asymmetry • Surgical release if persistent
• Poor eye development is concern
XR: Spine/hips: r/o other deformities
72 NETTER’S CONCISE ORTHOPAEDIC ANATOMY
SURGICAL APPROACHES • Spine 2
Longus Anterior Approach to Cervical Spine
colli
Transverse
incisions at
desired level
(left side
preferred)
Prevertebral
fascia (opened)
Intervertebral disc
Vertebral body
Longus colli
(retracted)
Esophagus (retracted)
Trachea (retracted)
Disc Pretracheal
fascia
Deep
cervical fascia
Sternocleidomastoid
Carotid sheath
Prevertebral fascia
USES INTERNERVOUS PLANE DANGERS COMMENT
• Anterior cervical dis- ANTERIOR APPROACH • Access C3 to T1
kectomy & fusion • Right recurrent laryngeal nerve
(ACDF) for cervical Superficial • Recurrent laryngeal n.
spondylosis and/or Deep cervical fascia: SCM • Sympathetic n. more susceptible to injury;
HNP goes lateral • Carotid artery many surgeons approach on
Pretracheal fascia: carotid • Internal jugular left side
• Tumor or biopsy sheath goes lateral • Vagus nerve • Thyroid arteries limit extension
Deep • Inferior thyroid artery of the approach
Prevertebral fascia be-
tween longus collis
muscles (right & left)
NETTER’S CONCISE ORTHOPAEDIC ANATOMY 73
2 Spine • SURGICAL APPROACHES
Posterior Approach to Cervical Spine
Incision Paraspinous
site muscles (retracted)
C-2 Vertebral lamina
C-7 Ligamentum flavum
Vertebral spine
Interspinous
ligament
Atlantoaxial
Paraspinous muscles capsule
Vertebral lamina
Incision site Posterior Approach to Lumbar Spine
Erector spinae
Erector spinae muscle (reflected)
muscle Vertebral spine
Vertebral lamina
Vertebral lamina
USES INTERNERVOUS PLANE DANGERS COMMENT
• Posterior fusion/spondylosis POSTERIOR APPROACH • Most common C-spine
• Facet dislocation approach
Cervical
• Herniated disc (HNP)/nerve • Mark level of pathology with
compression & diskectomy Left and right paracervical • Spinal cord radiopaque marker preop to
muscles (posterior cervi- • Nerve roots assist finding the appropri-
• Lumbar fusion cal rami) • Posterior rami ate level intraoperatively
• Vertebral artery
• Segmental vessels • Incision is along the spinous
processes
Lumbar
Left and right paraspinal • Segmental vessels
muscles (dorsal rami) to paraspinals
74 NETTER’S CONCISE ORTHOPAEDIC ANATOMY
Topographic Anatomy CHAPTER 3
Osteology
Radiology Shoulder
Trauma
Joints 76
Minor Procedures 77
History 79
Physical Exam 80
Muscles 85
Nerves 88
Neurovascular Structures 89
Arteries 90
Disorders 94
Pediatric Disorders 98
Surgical Approaches 100
101
102
105
106
3 Shoulder • TOPOGRAPHIC ANATOMY Biceps brachii muscle
Triceps brachii muscle
Sternocleidomastoid muscle
Sternal head Axilla
Anterior axillary fold
Clavicular head Posterior axillary fold
Clavicle (pectoralis major)
Acromioclavicular joint Pectoralis major muscle
Acromion Clavicular head
Sternoclavicular joint Sternal head
Deltoid muscle Latissimus dorsi muscle
Cephalic vein Serratus anterior muscle
Trapezius muscle Deltoid muscle
Spine of scapula
Deltoid muscle Spine of scapula
Infraspinatus muscle Triangle of auscultation
Triceps brachii
muscle Medial border of scapula
Long head
Lateral head Inferior angle of scapula
Tendon
Teres major muscle
Latissimus dorsi muscle
STRUCTURE CLINICAL APPLICATION
Sternoclavicular (SC) joint Uncommon site of infection or dislocation
Clavicle Subcutaneous bone: most common bone to fracture
Acromioclavicular (AC) joint Common site of “shoulder separation” or degenerative joint disease/pain
Acromion Landmark of shoulder (especially for injections, e.g., subacromial)
Deltoid muscle Can test muscle function for axillary nerve motor function
Trapezius Common site of pain; weakness results in lateral scapular winging
Serratus anterior Weakness/palsy results in medial scapular winging
Pectoralis major Can rupture off humeral insertion, results in a defect in the axillary fold
Cephalic vein Lies in the deltopectoral interval
Spine of scapula More prominent with supra/infraspinatus muscle wasting (suprascapular nerve palsy)
Inferior angle of scapula May “wing” medially or laterally if muscles are weak (nerve palsies)
76 NETTER’S CONCISE ORTHOPAEDIC ANATOMY
OSTEOLOGY • Shoulder 3
Acromial angle Acromion Coracoid process Clavicle (cut)
Superior angle
Supraglenoid
tubercle Superior border
Anatomical neck
Suprascapular notch
Greater tubercle
Neck
Lesser tubercle
Medial border
Surgical neck
Intertubercular Subscapular fossa
sulcus (bicipital
groove) Glenoid Infraglenoid tubercle
cavity of Lateral border
Crest of scapula Inferior angle
greater tubercle
Head of
Crest of humerus Scapula
lesser tubercle
Humerus Suprascapular notch Clavicle (cut)
Deltoid tuberosity Coracoid process
Superior border Acromion
Acromial angle
Superior angle Spinoglenoid notch (notch
connecting supraspinous
Supraspinous fossa and infraspinous fossae)
Spine Greater tubercle
Neck Head of humerus
Infraspinous fossa
Medial border Anatomical neck
Lateral border Groove for Surgical neck
Inferior angle circumflex Infraglenoid tubercle
scapular Deltoid tuberosity
vessels
Scapula Humerus Radial groove
CHARACTERISTICS OSSIFY FUSE COMMENTS
• Flat, triangular bone SCAPULA • Suprascapular nerve can be compressed
• Spine posteriorly in suprascapular notch (denervates SS &
Primary 8wk fetal 15-20yr IS) or in the spinoglenoid notch (dener-
separates two fossae Body vates IS only)
(supra/infraspinatus)
• Two notches Secondary 1yr All fuse • Suprascapular & spinoglenoid notches
• Coracoid process Coracoid 15-18yr between • Coracoid is the “lighthouse” to the
anteriorly Glenoid 15-18yr 15-20yr
• Glenoid: pear shaped Acromion 15-18yr shoulder
• Acromion: hook-shaped Inferior angle • Glenoid: 5-7° retroverted, 5° superior tilt
lateral prominence • Unfused acromion results in os acromiale
PROXIMAL HUMERUS • Body of scapula is very thin, angle is
• Head is retroverted: 35°
• Anatomic and surgical Primary 8-9wk Birth thicker
Shaft fetal
necks • Anatomic neck fxs: risk for osteonecrosis
• Head/neck angle: 130° Secondary 17-20yr • Surgical neck: common fx site (especially
• Two tuberosities: Proximal (3):
Birth in the elderly)
Greater is lateral Head 1-2yr • 80% of bone growth from proximal
Lesser is anterior Gtr tuberosity 3-4yr
• Bicipital groove between Lsr tuberosity physis; proximal fxs in children have
gtr and lsr tuberosities: great remodeling potential
bicep tendon • Greater tuberosity: insertion site of su-
praspinatus, infraspinatus, teres minor
• Lesser tuberosity: insertion site of
subscapularis
NETTER’S CONCISE ORTHOPAEDIC ANATOMY 77
3 Shoulder • OSTEOLOGY
Superior surface
Acromial Posterior
end Anterior
Shaft body Sternal end
Acromial facet Inferior surface Impression for
Anterior costoclavicular ligament
Trapezoid line Posterior Sternal facet
Conoid tubercle
Subclavian groove Clavicle
(for subclavius muscle)
Acromion
Coracoid process
X-ray, clavicle
Acromion X-ray, clavicle Clavicle
Humeral head
Coracoid process
Clavicle Glenoid
Acromioclavicular joint
Acromioclavicular
Acromion joint
Coracoclavicular
distance
Sternoclavicular joint
X-ray, AC joints
CHARACTERISTICS OSSIFY FUSE COMMENTS
• S-shaped cylindrical bone CLAVICLE • Only link from upper extremity to
• Middle 1⁄3 is narrowest, axial skeleton
Primary (2)
no muscle insertions Medial & lateral 7wk fetal 9wk fetal • Most commonly fractured bone in
• Clavicle widens laterally body; middle 1⁄3 is most common
• No true medullary canal Secondary 18-20yr 19-25yr location of fracture (80%)
Sternal 18-20yr 19-22yr
Acromial • First bone to ossify, last to fuse
• Starts as intramembranous, then fin-
ishes as membranous ossification
78 NETTER’S CONCISE ORTHOPAEDIC ANATOMY
Clavicle Acromion RADIOLOGY • Shoulder 3
(slight hook)
Coracoid Humeral
process Greater head
tuberosity Coracoid
process
Humeral
head
Glenoid
X-ray, scapular X-ray axillary, lateral
Acromion Clavicle Acromion
Humeral Clavicle Humeral
head head
Coracoid
Greater process
tuberosity
Glenoid
Lesser Glenoid
tuberosity
X-ray, AP Coronal, CT
RADIOGRAPH TECHNIQUE FINDINGS CLINICAL APPLICATION
CLAVICLE
Clavicle (2 view) AP w/caudal & cephalic tilt Clavicle Fracture, DJD of ACJ
Zanca AP (of ACJ) w/10° cephalic tilt Acromioclavicular joint ACJ pathology (DJD, fx)
Stress views Both ACJs w/w-out weights Acromioclavicular joints ACJ separation/instability
Serendipity 40° cephalic tilt manubrium Sternoclavicular joint Sternoclavicular pathology
SHOULDER
AP Plate perpendicular to scapula Glenohumeral joint space Trauma (fx/dx), arthritis
Axillary lateral Abduct arm, beam into axilla Glenoid/humeral head position Dislocations, Hill-Sachs lesion
Scapular Y Beam parallel to scapula Humeral head position Trauma, acromion type
Supraspinatus Scapular Y w/10° caudal tilt Acromion morphology Hooked acromion (type 3) is
outlet assoc. w/ impingement synd.
Stryker notch Hand on head, 10° cephalic tilt Humeral head Hill-Sachs lesion
West point Bony Bankart lesion
Prone, beam into axilla Anterior inferior glenoid
CT Fractures (esp. proximal hu-
OTHER STUDIES merus, glenoid/intraarticular)
MRI Rotator cuff or labral tears
Axial, coronal, sagittal Articular congruity, fx fragment
position
Sequence protocols vary Soft tissues (tendons, labrum)
NETTER’S CONCISE ORTHOPAEDIC ANATOMY 79
3 Shoulder • TRAUMA
Fractures of lateral third of clavicle
Type I. Fracture with no Type IIA. Fracture is Type IIB. Fracture is Type III. Fracture through
disruption of ligaments and medial to ligaments. Both between ligaments; coroid acromioclavicular joint;
therefore no displacement. ligaments are intact. is disrupted, trapezoid is no displacement. Often
Treated with simple sling intact. Medial fragment missed and may later cause
for few weeks may elevate. painful osteoarthritis requir-
ing resection arthroplasty
DESCRIPTION EVALUATION CLASSIFICATION TREATMENT
CLAVICLE FRACTURE
• Most common fx Hx: Trauma/fall, pain • Group 1: middle 1/3 • Closed treatment/sling
• 80% in middle third PE: Swelling, tenderness. for most groups 1&
• Group 2: distal 1/3 3 fxs
(group 1) ϩ/Ϫ tenting of skin/ ؠType 1: lateral to
• 15% group 2, 5% group 3 clinical deformity; do CC ligaments • ORIF for fxs severely
• Mechanism: fall onto thorough neurovascular ؠType 2a: medial to shortened, tented,
exam CC ligaments open, associated with
shoulder (e.g., football, XR: 2 views of clavicle ؠType 2b: between vascular injuries
hockey) (evaluate for shortening) CC ligaments (conoid
• Clavicle is unfused until CT: Rarely needed • ORIF for most group
early 20’s, periosteal torn, trapezoid intact) 2/type 2 distal fxs
sleeve avulsion fx can re- ؠType 3: fx into ACJ
sult distally • Group 3: proximal 1/3
COMPLICATIONS: Nonunion (esp. distal/group 2 fx); vascular or nerve injury
SCAPULA FRACTURE
• Mechanism: high-energy Hx: Trauma (e.g., MVA), • Anatomic classification: A-G • Closed treatment with
trauma pain in back and/or sling for 2wk for most
shoulder • Ideberg (glenoid fx) fxs, then early ROM
• Uncommon injury PE: Swelling, tenderness ؠType I: anterior avulsion fx
• Young males most to palpation, decreased ؠType II: transverse/oblique • ORIF for displaced,
ROM fx through glenoid; exits unstable, or large
common XR: AP/axillary lateral/ (Ͼ25%) intraarticular
• Ͼ85% have associated scapular Y; CXR inferiorly or angulated neck fxs
CT: Intraarticular/glenoid ؠType III: oblique fx through
injuries: pulmonary contu- fractures, displaced
sion, pneumothorax body fractures glenoid, exits superiorly
• Good healing potential ؠType IV: transverse fx exits
provided by surrounding
muscles through the scapula body
ؠType V: types II ϩ IV
COMPLICATIONS: Associated injuries: Rib fracture #1, pulmonary contusion, pneumothorax, vascular or brachial plexus
80 NETTER’S CONCISE ORTHOPAEDIC ANATOMY
TRAUMA • Shoulder 3
Grade 1 Grade 2
Grade 3 Grade 4
Grade 5 Grade 6
DESCRIPTION EVALUATION CLASSIFICATION TREATMENT
ACROMIOCLAVICULAR SEPARATION
• Mechanism: fall onto Hx: Fall/direct blow, pain, Rockwood grade: • Grades I & II: sling,
shoulder (e.g., football, swelling, ϩ/Ϫ popping I. AC ligament sprain rest, physical therapy
bicycles, etc) PE: AC tenderness, ϩ/Ϫ II. AC tear, CC intact
instability & deformity III. AC & CC ligament tears Յ • Grade III: controversial.
• Progression from isolated XR: AC joint (ϩ/Ϫ stress 100% superior displacement Nonoperative for most,
AC ligament injury to views, esp. grade II) IV: Grade III w /posterior CC reconstruction for
combined AC and CC (measure CC distance) displacement high-level athletes &
(coracoclavicular) ligament MR: Evaluate CC V: Grade III Յ 300% superior laborers
disruption with varying ligaments displacement
clavicle displacement VI: Grade III w/ inferior • Grades IV-VI: CC liga-
displacement ment reconstruction
• Aka “shoulder separation”
COMPLICATIONS: AC arthrosis/DJD; stiffness; associated injuries (pneumothorax, fracture, neurapraxia)
NETTER’S CONCISE ORTHOPAEDIC ANATOMY 81
3 Shoulder • TRAUMA
Anterior Dislocation
Anterior dislocation (most Anteroposterior radiograph
common) Anterior dislocation
Posterior Dislocation
Posterior
(subacromial)
dislocation
Antero- Lateral
posterior view
view
Anteroposterior radiograph. Lateral radiograph (parallel True axillary view. Also shows humeral
Difficult to determine if to plane of body of scapula). head posterior to glenoid cavity.
humeral head within, Humeral head clearly seen
anterior, or posterior to to be posterior to glenoid
glenoid cavity. cavity.
DESCRIPTION EVALUATION CLASSIFICATION TREATMENT
GLENOHUMERAL DISLOCATION
• Most common dislocation Hx: Trauma/fall, pain, in- Anatomic (based on loca- • Acute: reduce dislocation
• Common in young/athletic ability to move arm tion of humeral head):
PE: “Flattened” shoulder, • Anterior (Ͼ90%) • Methods (with sedation):
patients (recurrence Ͼ90% no ROM, test axillary • Posterior (often missed) ؠHippocratic/traction
if Ͻ25y.o.) nerve function • Inferior (luxatio erecta: ؠStimson
• Associated w/ labral tears XR: 3-view shoulder; abducted arm cannot ؠMilch
(Ͻ40y.o.) and rotator cuff must have axillary lateral be lowered [rare]) ؠScapular retraction
tears (Ͼ40y.o.) for posterior dislocation • Superior (extremely
• Associated with fxs: tuber- CT: To evaluate fxs: tuber- rare) • Immobilize: sling for 2wk
osity or glenoid rim (“bony osity or glenoid
Bankart”) • Physical therapy
• Posterior dislocations asso-
ciated w/ seizures • ORIF of displaced fxs
• Humeral head impression
fracture (Hill-Sachs lesion) • Consider early labral
can occur
repair in young patients
COMPLICATIONS: Recurrent dislocation/instability (esp. in young/Ͻ25y.o.); nerve injury (axillary, musculocutaneous)
82 NETTER’S CONCISE ORTHOPAEDIC ANATOMY
TRAUMA • Shoulder 3
Reduction of Anterior Dislocation of Glenohumeral Joint
Stimson maneuver
Patient prone on table with affected limb
hanging freely over edge; 10–15-lb weight
suspended from wrist. Gradual traction
overcomes muscle spasm and in most cases
achieves reduction in 20–25 minutes.
Milch maneuver
Patient supine; steady downward
traction applied at elbow,
combined with slow, gradual
external rotation and abduction of
limb.
Hippocratic maneuver
Patient supine on table. Examiner places sole of foot
(shoe removed) against patient’s axillary fold for
countertraction, grasps patient’s wrist with both
hands, and applies steady longitudinal traction.
Ancient but occasionally useful method.
NETTER’S CONCISE ORTHOPAEDIC ANATOMY 83
3 Shoulder • TRAUMA
Supraspinatus and Rotator interval
external rotator mm. Anatomic neck
Neer four-part classification of 13 Greater
fractures of proximal humerus. 2 tuberosity
1. Articular fragment (humeral
head). 4 Surgical neck
2. Lesser tuberosity. Lesser Long tendon of
3. Greater tuberosity. tuberosity biceps brachii m.
4. Shaft. If no fragments
displaced, fracture considered Subscapularis m.
stable (most common) and
treated with minimal external
immobilization and early
range-of-motion exercise.
Neer Classification of Proximal Humerus Fractures
2 Part 3 Part 4 Part
Anatomical neck
Surgical neck
Greater tuberosity Greater tuberosity Greater and lesser
tuberosities
Lesser tuberosity Lesser tuberosity
DESCRIPTION EVALUATION CLASSIFICATION TREATMENT
PROXIMAL HUMERUS FRACTURE
• Common fx, esp. in Hx: Trauma/fall, pain, • Neer: based on number of • 1 part: sling, early motion
elderly/osteoporotic difficult to move arm parts (fragments) • 2 part: closed reduction &
patients PE: Humeral tenderness,
decreased ROM, ϩ/Ϫ • Parts (4): head, GT, LT, coaptation splint, then PT
• Proximal humeral cancel- deformity shaft • 3 part: operative: PCP vs
lous bone is susceptible XR: 3-view shoulder
to fx CT: Identify fragments • Fragment must be Ͼ1cm ORIF (locking plate)
and displacement displaced or 45° angula- • 4 part: ORIF vs hemi-
• Muscular attachments tion to be considered a
determine displacement “part” arthroplasty
pattern
• Multiple combinations of
• Most are minimally fragments/parts possible
displaced/1-part fxs
• Associated with rotator
cuff tears
COMPLICATIONS: Shoulder stiffness, AVN (anatomic neck fractures), nerve injury (axillary, brachial plexus), nonunion
84 NETTER’S CONCISE ORTHOPAEDIC ANATOMY
JOINTS • Shoulder 3
Anterior sternoclavicular ligament Sternoclavicular Joint Articular disc of
Clavicle sternoclavicular joint
Interclavicular
Subclavius muscle ligament Articular cavities of
Costoclavicular ligament sternoclavicular joint
1st rib Costoclavicular ligament
Costal cartilages Synchondrosis of 1st rib
2nd rib Manubrium
Radiate sternocostal ligament
Sternocostal
(synovial) joint
Manubriosternal synchondrosis
LIGAMENT ATTACHMENTS COMMENTS
SHOULDER JOINTS
General
• The shoulder is made up of 4 separate articulations. Shoulder motion is a combined movement from all 4 articula-
tions: 1. Sternoclavicular joint, 2. Glenohumeral joint, 3. Acromioclavicular joint, 4. Scapulothoracic articulation
• The shoulder joint has the most range of motion in the body.
ؠForward flexion: 0-170°
ؠExtension: 0-60°
ؠAbduction: 0-170/180°
ؠInternal rotation: to thoracic spine
ؠExternal rotation: up to 70°
• 2:1 ratio of glenohumeral joint to scapulothoracic articulation motion during shoulder abduction
• Inherently unstable joint with huge ROM potential. Static and dynamic stabilizers give joint stability.
ؠStatic: glenoid, labrum, articular congruity, glenohumeral ligaments & capsule, negative intraarticular pressure
ؠDynamic: rotator cuff muscles/tendons, biceps tendon, scapular stabilizers (periscapular muscles), proprioception
• Shallow glenoid “socket” gives minimal bony stability, but is deepened/stabilized by the fibrocartilaginous labrum.
• Labrum serves as a “bumper”/stop to humeral subluxation, as well attachment site for capsuloligamentous structures.
Joint instability can result from labral tear/detachment with loss of “bumper” and resultant ligamentous laxity.
• Rotator cuff: confluent “horseshoe-” shaped insertion of 4 stabilizing muscle tendons inserting on the proximal hu-
merus (greater & lesser tuberosities). RC muscles actively keep humeral head seated into glenoid during all motions.
STERNOCLAVICULAR JOINT
Diarthrodial/double gliding joint. Only true attachment of upper extremity to axial skeleton. ROM: clavicle rotates in joint
up to 50° on the fixed sternum.
Capsule Surrounds joint Secondary stabilizer
Sternoclavicular Medial clavicle to sternum Primary stabilizer of sternoclavicular joint
Anterior and posterior ligaments Posterior stronger, anterior dislocation more common
Costoclavicular Inferior clavicle to costal cartilage Strongest sternoclavicular ligament
Interclavicular Between medial ends of clavicle Secondary stabilizer
Disc Intraarticular disc Fibrocartilage disc within the joint
SCAPULOTHORACIC ARTICULATION
The articulation is not an actual joint. Scapula slides/rotates along posterior ribs (2-7). Multiple muscles (including serra-
tus anterior and trapezius) are involved. 2:1 ratio of GHJ to scapulothoracic motion during flexion & abduction
NETTER’S CONCISE ORTHOPAEDIC ANATOMY 85
3 Shoulder • JOINTS
Coronal section through joint Joint opened: lateral view
Acromion Acromioclavicular Acromion Coracoacromial Coracoid process
Synovial membrane
joint Supraspinatus ligament Coracohumeral
Glenohumeral Glenoid tendon (fused ligament
ligament labrum, to capsule)
(SGHL) superior Biceps brachii
Sub- Subdeltoid tendon
deltoid Glenoid bursa (long head)
bursa labrum, Infraspinatus tendon Superior
Supra- inferior (fused to capsule) glenohumeral
spinatus ligament
tendon Glenoid Glenoid cavity
Deltoid cavity of (cartilage) Subscapularis
muscle scapula tendon
Axillary recess Teres minor tendon (fused to capsule)
(pouch) (fused to capsule)
Middle glenohumeral
Synovial membrane ligament
(cut edge)
Inferior glenohumeral
Posterior band ligament
Openings of subtendinous Anterior band
bursa of subscapularis
MRI axial, shoulder Key MRI coronal, shoulder Key
G^ G Greater tuberosity as D Deltoid
L# L Lesser tuberosity D* s Supraspinatus
h* h Humeral head +g + Supraspinatus
+s ^ Biceps tendon
# Subscapularis tendon G tendon
g s Subscapularis a Acromion
g Glenoid G Greater
* Anterior labrum
+ Posterior labrum tuberosity
* Superior labrum
g Glenoid
LIGAMENT ATTACHMENTS COMMENTS
GLENOHUMERAL JOINT
Spheroidal (“ball & socket”) joint. Inherently unstable joint stabilized by dynamic and static restraints
Glenohumeral Ligaments
Superior (SGHL) Anterosuperior glenoid rim/labrum to Resists inferior translation & ER in shoulder adduction
proximal lesser tuberosity Resists posterior translation in 90° of forward flexion
Middle (MGHL) Anterosuperior glenoid rim/labrum (in- Resists anteroposterior translation in 45° of abduction
ferior to SGHL) to just medial to Secondary restraint to translation & ER in adduction
lesser tuberosity Buford complex: thickened MGHL & absent anterior/
superior labrum
Inferior (IGHL) Most important ligament, forms sling that tightens in abduction & ER (ant. band)/IR (post. band)
• Anterior band Anterior glenoid/labrum (3 o’clock) to Resists anterior & inferior translation in abduction & ER;
(AIGHL) inferior humeral neck must be tightened/“shifted” in anterior instability or MDI
• Posterior band Posterior glenoid/labrum (9 o’clock) to Resists posterior translation in IR & 90° flexion
(PIGHL) inferior humeral neck
Other
Coracohumeral Coracoid base to both LT and GT With SGHL, resists inferior translation in adduction; part of
(CHL) (either side of bicipital groove) pulley to stabilize biceps tendon in joint and groove
Labrum Circumferentially attached to glenoid Fibrocartilage: deepens glenoid, provides more contact
area, adds stability; insertion site for some GH ligaments
Capsule Surrounds joint Maintains intraarticular negative pressure, thin posteriorly
• Glenohumeral ligaments: Discrete thickenings of anterior and inferior capsule that provide stability to the joint. There
are no ligaments posteriorly or superiorly.
• Rotator interval: Triangular space between anterior border of supraspinatus and superior border of subscapularis
ؠContents: SGHL, CHL, and biceps tendon, anterosuperior glenohumeral capsule
ؠTightening of this interval can decrease the inferior translation in adduction/”sulcus sign” in the unstable shoulder
• Biceps pulley: SGHL, CHL, subscapularis form an anterior pulley to keep biceps tendon located in joint/bicipital groove
86 NETTER’S CONCISE ORTHOPAEDIC ANATOMY
Arthroscopy of Shoulder JOINTS • Shoulder 3
Labrum Subscapularis Middle glenohumeral ligament MRI sagittal, shoulder
tendon
Biceps Labrum Acromion
tendon Clavicle
Glenoid Supraspinatus
muscle
Glenoid Humerus Inferior
glenohumeral Biceps
Middle glenohumeral ligament ligament Humerus tendon
Subscapularis
tendon
Supraspinatus
tendon
Infraspinatus
tendon
Infraspinatus Teres minor
muscle
Acromioclavicular joint capsule Anterior view Clavicle
(incorporating acromioclavicular ligament)
l Trapezoid Coraco-
Acromion t ligament clavicular
Coracoacromial ligament ligament
Supraspinatus tendon (cut) Glenohumeral Conoid
Coracohumeral ligament ligaments ligament
Greater tubercle and Superior transverse
Lesser tubercle scapular ligament and
of humerus suprascapular notch
Transverse humeral ligament
Coracoid process
Intertubercular (bicipital) tendon
sheath (communicates with synovial cavity) Communications of
subtendinous
Subscapularis tendon (cut) bursa of subscapularis
Biceps brachii tendon (long head) Broken line indicates
position of subtendinous
bursa of subscapularis
LIGAMENT ATTACHMENTS COMMENTS
ACROMIOCLAVICULAR JOINT
Diarthrodial (plane/gliding) joint. Very limited motion (5° rotation). Common site of injury and/or painful degeneration.
Capsule Surrounds joints Weak stabilizer, but sufficient under routine loads
Acromioclavicular Thickening of superior capsule Provides anterior to posterior stability and axial stability
Injured (to some degree) in all AC separations
Coracoclavicular Coracoid base to inferior clavicle Provides vertical stability to the clavicle at the AC joint
ؠConoid Posteromedial insertion on clavicle Stronger resistance to vertical load than trapezoid
ؠTrapezoid Anterolateral insertion on clavicle Resists axial load to shoulder (more oblique fibers)
Disc In joint, between clavicle & acromion Interposed to cushion partially incongruent joint
OTHER STRUCTURES
Coracoacromial Coracoid tip to anterior and inferior Key component of the coracoacromial arch; prevents
acromion humerus migration in rotator cuff–deficient shoulder
Superior transverse Crosses suprascapular notch Suprascapular nerve travels under ligament, suprascap-
scapular ular artery crosses over it.
Transverse humeral Lesser tuberosity to greater tuberos- Stabilizes biceps tendon within the bicipital groove
ity (crosses bicipital groove) Lateral aspect of rotator interval
NETTER’S CONCISE ORTHOPAEDIC ANATOMY 87
3 Shoulder • MINOR PROCEDURES
Acromioclavicular Subacromial
injection approach injection/aspiration
(posterior approach)
Glenohumeral
Subacromial (posterior
injection/aspiration approach)
(lateral approach)
STEPS
INJECTION OF ACROMIOCLAVICULAR JOINT
1. Ask patient about allergies
2. Palpate clavicle distally to AC joint (sulcus)
3. Prep skin (iodine/antiseptic soap) over AC joint
4. Anesthetize skin with local (quarter size spot)
5. Use 25g needle, insert needle into sulcus vertically (or with slight lateral to medial tilt) and into joint. You should feel a
“pop/give” as the needle enters the joint. Inject 2ml of 1:1 local/corticosteroid preparation (the joint may hold Ͻ2ml
of fluid). A subcutaneous wheal indicates that the needle tip is superficial to the AC capsule.
6. Dress injection site
INJECTION OF THE SUBACROMIAL SPACE
1. Ask patient about allergies
2. Palpate the acromion: define its borders (esp. lateral border & posterolateral corner)
3. Prep skin (iodine/antiseptic soap) over acromial edge
4. Anesthetize skin with local (quarter size spot)
5. Hold finger (sterile glove) on acromion, insert needle under acromion (lateral or posterior) w/ slight cephalad tilt.
Aspirate to ensure not in a vessel, then inject 5ml of preparation; will flow easily if in joint. Use: a. diagnostic
injection: local only; b. therapeutic injection: local/corticosteroid
6. Dress injection site
GLENOHUMERAL INJECTION
1. Ask patient about allergies
2. Palpate the posterior shoulder for the “soft spot” (usually 2cm down, 1cm medial to posterolateral corner of the acro-
mion). Also palpate the coracoid process on the anterior aspect of the shoulder.
3. Prepare skin (iodine/antiseptic soap) over the “soft spot” on posterior shoulder
4. Anesthetize the skin overlying the “soft spot” (quarter size spot)
5. With sterile gloves, palpate the “soft spot” and the coracoid process. Then insert the needle into the soft spot and aim
it toward the coracoid process. If the needle hits bone it should be redirected (glenoid: move lateral; humerus: move
medial). Aspirate to ensure not in a vessel. Inject preparation (local ϩ/Ϫ corticosteroid) into joint (should flow easily if
in the joint space)
6. Dress injection site
88 NETTER’S CONCISE ORTHOPAEDIC ANATOMY
HISTORY • Shoulder 3
Injury to acromioclavicular joint. Usually caused Throwing athletes can develop rotator cuff tears,
by fall on tip of shoulder, depressing acromion internal impingement, and motion abnormalities
(shoulder separation)
Shoulder instability is common in swimmers
QUESTION ANSWER CLINICAL APPLICATION
1. Age Old
Rotator cuff tear, impingement, arthritis (OA), adhesive
2. Pain Young capsulitis (frozen shoulder), humerus fracture (after fall)
a. Onset Instability, labral tear, AC injury, distal clavicle osteolysis,
b. Location impingement in athletes
c. Occurrence
d. Exacerbating/ Acute Fracture, dislocation, rotator cuff tear, acromioclavicular
relieving injury
Chronic Impingement, arthritis/DJD, rotator cuff tear
3. Stiffness On top/AC joint AC joint arthrosis/separation
4. Instability Night pain Classic for RC tear, tumor (rare)
Overhead worse Rotator cuff tear, impingement
5. Trauma Overhead better Cervical radiculopathy
6. Work/activity Yes Osteoarthritis (OA), adhesive capsulitis
7. Neurologic sx “Slips in and out” Dislocation (Ͼ90% anterior, esp. in abduction & ER (e.g.,
8. PMHx throwing), subluxation, labral tear
Direct blow
Fall on outstretched hand Acromioclavicular (AC) injury
Glenohumeral dislocation (subluxation; fracture)
Overhead usage
Weight lifting Rotator cuff tear
Athlete: throwing type Osteolysis (distal clavicle)
Long-term manual labor RC tear/impingement (internal), instability (swimmer’s)
Arthritis (OA)
Numbness/tingling/”heavy”
Thoracic outlet syndrome, brachial plexus injury
Cardiopulmonary/GI
Referred pain to shoulder
NETTER’S CONCISE ORTHOPAEDIC ANATOMY 89
The words you are searching are inside this book. To get more targeted content, please make full-text search by clicking here.
Netter's Concise Orthopaedic Anatomy 2nd Edition
Discover the best professional documents and content resources in AnyFlip Document Base.
Search