Netter's Concise Orthopaedic Anatomy 2nd Edition

6 Hand • TENDONS

Extensor zones of hand

Flexor zones of hand I DIP joint T-I IP joint
II Middle phalanx T-II Proximal phalanx
III T-III MP joint
III PIP joint T-IV Metacarpal
I II II II T-I IV Proximal phalanx T-V CMC joint radial styloid
II
V MP joint
III VI Metacarpal
T-III VII Dorsal retinaculum

IV VIII Distal forearm

T-II

V

IX Mid and proximal
forearm

ZONE BOUNDARIES COMMENT
FLEXOR TENDON ZONES
I Distal to FDS Single tendon (FDP) injury. Primary repair. DIPJ contracture results if tendon short-
insertion ened Ͼ1cm. Quadriga effect can also result
II Finger flexor “No man’s land.” Both tendons(FDS, FDP) require early repair (within 7 days) and mo-
retinaculum bilization. Lacerations may be at different locations on each tendon and away from
III skin laceration. Preserve A2 & A4 pulleys during repair
IV Palm Primary repair. Arterial arch & median nerve injuries common.
V Carpal tunnel Must release & repair the transverse carpal ligament during tendon repair.
Thumb I Wrist & forearm Primary repair (ϩ any neurovascular injury). Results are usually favorable.
Distal to FPL Primary tendon repair. Rerupture rate is high.
Thumb II
insertion Primary tendon repair. Preserve either A1 or oblique pulley.
Thumb III Thumb flexor
Do not operate in this zone. Recurrent motor branch is at risk of injury.
I retinaculum EXTENSOR TENDON ZONES
II Thenar eminence
III “Mallet finger.” Splint in extension for 6 wk continuously.
DIP joint Complete lacerations: primary repair and extension splint.
IV Middle phalanx Central slip injury. Splint in extension for 6 wk. If triangular ligament is also disrupted,
V PIP joint lateral bands migrate volarly, resulting in “boutonniere finger”
VI Primary repair of tendon (and lateral bands if needed), then extension splint
VII Proximal phalanx Often from “fight bite.” Repair tendon and sagittal bands as needed.
VIII MCP joint Primary repair and early mobilization/dynamic splinting.
IX Metacarpal Retinaculum likely injured. Primary tendon repair, early mobilization.
Wrist At musculotendinous jxn. Primary repair of tendinous tissue & immobilize
Distal forearm Often muscle injury. Neurovascular injury high. Repair muscle & immobilize.
Proximal forearm

190 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

A1 C1 TENDONS • Hand 6

Tendons of flex- Pulleys
or digitorum A2 C2 A3 C3 A4 C4 A5
superficialis
and profundus Volar plates (palmar ligaments)
muscles

(Synovial) tendinous sheath

Anterior (palmar) views Superficial palmar
Proper palmar digital nerves of thumb branch of radial
artery and recurrent
Common palmar digital artery branch of median
Proper palmar digital arteries and nerves nerve to thenar
Annular and cruciform parts of fibrous sheath muscles
over (synovial) flexor tendon sheaths
Ulnar artery
and nerve

Common palmar
digital branches
of median nerve (cut)

Hypothenar
muscles
Common flexor
sheath (ulnar
bursa)
5th finger
(synovial)
tendinous sheath

Insertion of
flexor digitorum
superficialis tendon

Insertion of flexor digitorum
profundus tendon

STRUCTURE DESCRIPTION COMMENT

Flexor tendon FLEXOR TENDON SHEATH
sheath
Pulleys Fibroosseous tunnel lined with tenosynovium Site of possible infection; check for Kanavel
Protects, lubricates, and nourishes the tendon signs (see Disorders table)
Vincula
Volar plate (palmar Thickenings of sheath to stabilize tendons 5 A2 & A4 (over P1 & P2) most important; must be
ligament) annular (A1[MCPJ], A3[PIPJ], A5[DIPJ] over intact to prevent “bowstringing” of tendons
joints; A2, A4 over phalanges) 3 or 4 cruci- Tight A1 can cause a trigger finger
ate pulleys A3 covers PIPJ volar plate: incise to access

Within sheath, give vascular supply to ten- Vincula torn in type 1 FDP rupture (dysvascular),
dons: 2 vincula (longa and brevia) preserved in types 2 & 3 rupture

Thickening of volar capsule of interphalan- FDS & FDP tendons insert here to flex the PIP &
geal joints DIP joints, respectively. Prevent hyperextension.

NETTER’S CONCISE ORTHOPAEDIC ANATOMY 191

6 Hand • JOINTS

Posterior (dorsal) view

Scaphoid

Triquetrum Capitate
Hamate Trapezium
Capsule of 1st carpo-
Dorsal carpometacarpal ligaments metacarpal joint
Dorsal metacarpal ligaments Trapezoid

5 1

4 32
Metacarpal bones

LIGAMENT ATTACHMENTS COMMENTS

CARPOMETACARPAL

Thumb

• Saddle joint. Highly mobile, has both inherent bony and ligamentous stability. Prone to develop osteoarthritis
• Primary movements: flexion, extension, adduction, abduction
• Complex (combined) movements: opposition, retropulsion, palmar abduction, radial abduction/adduction

Capsule Base of metacarpal to trapezium Surrounds joint and is a secondary stabilizer

Anterior (volar) oblique Ulnar side of 1st metacarpal base to “Beak” ligament. Holds fragment in Bennett’s fx.
tubercle of trapezium Primary restraint to subluxation. Injury can lead
to osteoarthritis.

Dorsal radial Dorsal trapezium to dorsal MC base Strongest. Dorsal and radial support. Torn in dorsal
dislocation.

1st intermetacarpal Ulnar 1st MC base to radial 2nd MC Prevents 1st metacarpal from translating radially
base

Posterior oblique Trapezium to dorsal ulnar MC base Secondary stabilizer

Ulnar collateral Volar ulnar trapezium to ulnar MC Limits abduction and extension
base

Radial lateral Radially on trapezium and MC base Under the APL tendon/insertion

Finger

• Gliding joints. 2nd & 3rd CMC have little motion, so minimal metacarpal fx angulation is acceptable b/c of immobility.
4th & 5th CMC have more anteroposterior motion, so more metacarpal fx angulation is acceptable b/c of mobility.

Capsule Base of metacarpal to carpus Adds stability

CMC ligaments Base of metacarpal to carpus Dorsal (strongest), volar, interosseous ligaments

Intermetacarpal Between adjacent metacarpal bases Adds ulnar and radial stability to CMC joint

192 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

Anterior (palmar) view JOINTS • Hand 6
Trapezium
Pisiform
Joint capsule Hook of hamate
Collateral ligaments Palmar carpometacarpal ligaments
Palmar metacarpal ligaments
Cut margins of
digital fibrous sheaths Deep transverse
Flexor digitorum metacarpal ligaments
superficialis tendons (cut)
Volar plates
(palmar ligaments)

Flexor digitorum profundus tendons

LIGAMENT ATTACHMENTS COMMENTS

METACARPOPHALANGEAL

Thumb

• Diarthrodial joint. Motion: primary ϭ flexion & extension; secondary ϭ rotation, adduction, abduction

Capsule Surrounds joint Secondary stabilizer dorsally. Taut in flexion

Proper collateral Center of metacarpal head to Primary stabilizer. Taut in flexion, test in 30° flexion
palmar proximal phalanx Ulnar collateral injured in “gamekeeper’s/skier’s” thumb

Accessory collateral Palmar to proper collateral lig. Taut in extension. Test integrity in extension.

Volar (palmar) plate Palmar metacarpal head to pal- Primary stabilizer in extension. Laxity in extension indi-

mar proximal phalanx base cates injury to volar plate (ϩ/Ϫ accessory collateral lig.)

Finger

• Diarthrodial joint. Motion: primary ϭ flexion & extension (ROM 0-90°); secondary ϭ radial & ulnar deviation
• Asymmetry of metacarpal head & collateral ligament origin result in “cam effect” (tight in flexion, loose in extension)

Capsule Surrounds joint Secondary stabilizer; synovial reflections volar & dorsal

Proper collateral Dorsal MC head to palmar P1 Primary stabilizer; tight in flexion, loose in extension
base

Accessory collateral Palmar MC head to volar plate Palmar to proper collaterals; stabilizes the volar plate

Volar (palmar) plate Palmar MC head to palmar P1 Limits extension; volar support
base

Deep transverse Between adjacent metacarpal Interconnects the volar plates, MCPJs, and metacarpals.
(inter)metacarpal bases and MCPJ volar plates Can prevent shortening of isolated metacarpal fractures.

NETTER’S CONCISE ORTHOPAEDIC ANATOMY 193

6 Hand • JOINTS Dorsal

Flexor digitorum Cleland’s lig. Palmar
profundus (FDP)
tendon Lateral digital sheet

Volar plate of PIPJ Neurovascular bundle
Flexor digitorum Digital a.
superficialis (FDS) Digital n.
tendon
Proximal Grayson’s lig.
phalanx (P1)
Extensor tendon

Accessory collateral ligament Proper collateral ligament Accessory
collateral
ligament

Metacarpophalangeal (MP) joint Proper Proximal interphalangeal Volar plates
Metacarpal bone collateral (palmar ligament)
ligament (PIP) joint
Dorsal surface Distal

interphalangeal

(DIP) joint

Palmar Proximal Middle Distal Note: Ligaments of
surface metacarpophalangeal
and interphalangeal
In extension: Phalanges joints are similar
medial view Volar plates (palmar ligament)
In flexion: medial view

LIGAMENT ATTACHMENTS COMMENTS

PROXIMAL INTERPHALANGEAL

• Hinge joints: Primary motion ϭ flexion & extension (PIPJ: ROM 0-110°, DIPJ: ROM 0-60°). Minimal rotation or devia-
tion motion. No “cam effect” in this joint. PIPJ is prone to stiffness/contracture after injury and/or immobilization.

Capsule Surrounds joint Weak stabilizer esp. dorsally (central slip adds most support)

Proper collateral Center of P1 head to volar P2 Primary stabilizer to deviation. Constant tension through ROM

Accessory collateral Volar proximal phalanx head Origin volar to axis of rotation: tight in ext., loose in flexion
to volar plate (not bone) This can result in a contracture (do not immobilize in flexion)

Volar (palmar) Volar middle phalanx to volar Primary restraint to hyperextension. Firm distal attachment,
plate proximal phalanx (via check- looser proximal attachment (more prone to injury).
rein ligaments) Checkrein ligaments often contract after injury: contracture

OTHER INTERPHALANGEAL

• Thumb interphalangeal (IPJ) and finger distal interphalangeal joints (DIPJ)
• Hinge joints: Primary motion ϭ flexion & extension (IPJ: ROM 0-90°; DIPJ: ROM 0-60°). Minimal rotation or deviation.

Capsule Surrounds joints Weak stabilizer

Proper collateral B/w adjacent phalanges Similar to PIPJ, constant tension, no “cam effect”

Accessory collateral Volar to collateral ligaments Similar to PIPJ, less prone to contracture than PIPJ

Volar (palmar) Volarly b/w phalanges Primary restraint to hyperextension; can be injured
plate

OTHER STRUCTURES

Grayson’s ligament From flexor sheath to skin; volar Stabilizes skin & neurovascular bundle

to neurovascular bundle Involved in Dupuytren’s disease/nodules

Cleland’s ligament From periosteum to skin Stabilizes skin during flexion/extension; dorsal to NV bundle

194 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

JOINTS • Hand 6

Insertion of small deep slip of extensor tendon Collateral lig.
to proximal phalanx and joint capsule
Extensor
Extensor expansion (hood) tendon

Sagittal band

Attachment of interosseous m. Volar plate Lumbrical m. Interosseous mm.
to base of proximal phalanx (palmar ligament)
and joint capsule
Flexor digitorum
Insertion of lumbrical superficialis tendon (cut)
m. to extensor tendon

Central band slip Collateral ligs. Note: Black arrows indicate
Conjoined lateral band pull of long extensor tendon;
Flexor digitorum red arrows indicate pull
Finger in flexion: profundus tendon (cut) of interosseous and
lateral view lumbrical muscles; dots
Volar plate indicate axis of
(palmar ligament) rotation of joints.

Terminal extensor
tendon insertion

MOTION STRUCTURE COMMENT
Flexion
Extension JOINT MOTION

Flexion Metacarpophalangeal Joint
Extension
Flexion Interosseous muscles Insert on proximal phalanx and lateral band (volar to
Extension Lumbricals rotation axis)
Inserts on radial lateral band (volar to axis of rotation
of MCPJ)

EDC via sagittal bands Sagittal bands insert on volar plate, creating a “lasso” around
proximal phalanx base and extend joint through the lasso.
EDC has minimal attachment to P1 (which does not extend
the joint) but extends joints via the sagittal bands.

Proximal Interphalangeal Joint

Flexor digitorum superficialis Primary PIPJ flexor via insertion on middle phalanx volar
(FDS) base
Flexor digitorum profundus Secondary PIPJ flexor
(FDP)

EDC via the central slip (band) Central slip of EDC inserts on dorsal P2 base to extend PIPJ
Lumbricals via lateral bands Has attachment to radial lateral band (dorsal to rotation axis)

Distal Interphalangeal Joint

Flexor digitorum profundus Tendon attaches at P3 volar base, pulls through tendon
(FDP) sheath

EDC via terminal extensor Lateral bands converge at terminal insertion on dorsal
tendon P3 base
Oblique retinacular ligament Links PIPJ & DIPJ extension; extends DIPJ as PIPJ is
(ORL) extended

NETTER’S CONCISE ORTHOPAEDIC ANATOMY 195

6 Hand • OTHER STRUCTURES

Insertion of central slip of extensor Oblique Lateral Extensor Sagittal Long extensor tendon
tendon to base of middle phalanx fibers bands expansion bands Interosseous muscles
(hood)
Triangular (aponeurosis)
ligament

Posterior Metacarpal bone
(dorsal)
view Conjoined Interosseous Part of interosseous
lateral bands tendon slip to tendon passes to base
Insertion on terminal extensor lateral band of proximal phalanx
tendon to base of distal phalanx Lateral slips of and joint capsule
long extensor
tendon to lateral bands Lumbrical
muscle

Conjoined Central Oblique Extensor expansion (hood)
Insertion of extensor tendon lateral bands slip Lateral fiber
to base of middle phalanx Sagittal bands
slip Long extensor tendon

Insertion of terminal extensor
tendon to base of distal phalanx

Metacarpal bone

Finger in Vincula Interosseous muscles
extension: longa Lumbrical muscle
lateral view Flexor digitorum profundus tendon

Collateral Vinculum Flexor digitorum superficialis tendon
ligaments breve

Lateral bands

STRUCTURE DESCRIPTION COMMENT

INTRINSIC APPARATUS

• Dorsal Extensor Aponeurosis (also called dorsal expansion, dorsal hood, extensor hood)

‫ ؠ‬Sagittal band Inserts on volar plate (P1); extensor tendon Extends MCPJ via “lasso” around P1 base;

(EDC) glides under it radial sagittal bands are weaker, may rupture

‫ ؠ‬Oblique fibers Covers MCPJ and base of proximal phalanx Holds EDC centered over MCPJ

‫ ؠ‬Lateral bands Lateral hood fibers join tendinous portion of Volar to MCPJ axis: flexes MCPJ
interossei/lumbricals to form lateral bands Dorsal to PIPJ axis: extends PIPJ

• Extrinsic Extensor Tendon (EDC) glides under the dorsal hood (to extend MCP) before trifurcating at prox. phalanx

‫ ؠ‬Lateral slip EDC trifurcates over P1 giving two lateral slips These slips conjoin with lateral bands

‫ ؠ‬Central slip Central slip of trifurcation; inserts base of P2 Extends PIPJ; torn in boutonniere injury

‫ ؠ‬Terminal extensor Confluence of two conjoined lateral bands on Extends DIPJ via insertion on dorsal base of

tendon dorsal base of distal phalanx (P3) P3; avulsed in mallet finger injury

• Conjoined lateral Confluence of EDC lateral slips and lateral Both join distally to make terminal extensor
band bands from extensor aponeurosis tendon

• Transverse retinacular From PIPJ volar plate and flexor sheath to Prevents conjoined lateral band dorsal sub-
luxation during PIPJ extension
ligaments both conjoined lateral bands

• Triangular ligament Transverse bands over P2, connects both Prevents lateral band volar subluxation in
(aponeurosis) conjoined lateral bands and terminal tendon PIPJ flexion; torn in boutonniere injury

• Oblique retinacular From volar P1 to dorsal P3/terminal tendon Extends DIPJ when PIPJ is extended
ligament (ORL)

OTHER STRUCTURES

Junctura tendinae Tendinous connections between ECD ten- Prevents full extension of finger when adja-
dons to adjacent fingers proximal to MCPJ cent digit is flexed (see page 155)

196 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

OTHER STRUCTURES • Hand 6

Tendinous sheath Tendinous sheath of Common
of flexor pollicis flexor pollicis longus flexor sheath
longus (radial bursa) (radial bursa) (ulnar bursa)
Common flexor
sheath (ulnar bursa) Flexor digitorum Flexor digitorum
profundus superficialis tendons
Thenar space tendons

Midpalmar Tendinous
space sheath of flexor
pollicis longus
Lumbrical muscles (radial bursa)
(in fascial
sheaths)

Synovial tendon
sheaths of fingers

Fascia of adductor pollicis muscle Common flexor sheath
Thenar space (ulnar bursa) (opened)
(deep to flexor tendon Lumbrical muscles in
and 1st lumbrical muscle) fascial sheaths
(Synovial) tendinous
sheath of finger Midpalmar space
Lumbrical muscles in fascial (deep to flexor tendons
sheaths (cut and reflected) and lumbrical muscles)
Fibrous and synovial (tendon)
Midpalmar space sheaths of finger (opened)

Palmar aponeurosis Flexor digitorum superficialis
Common palmar digital tendon (FDS)
artery and nerve Flexor digitorum profundus
Lumbrical muscle tendon (FPS)
in its fascial sheath
Flexor tendons to 5th Profundus and superficialis flexor tendons to 3rd digit
digit in common flexor Septum between midpalmar and thenar spaces
sheath (ulnar bursa) Thenar space
Hypothenar muscles
Flexor pollicis longus ten-
don in tendon sheath
(radial bursa)
Extensor pollicis
longus tendon

Adductor pollicis muscle

Palmar interosseous fascia

Dorsal interosseous fascia Palmar interosseous muscles
Dorsal interosseous muscles

Extensor tendons

STRUCTURE HAND SPACES COMMENT
Thenar space Potential space: site of possible infection
Midpalmar space CHARACTERISTICS Potential space: site of possible infection
Parona’s space Potential space: “horseshoe” abscess can
Between flexor tendons and adductor pollicis
Radial bursa occur here as infection tracks proximally
Ulnar bursa Between flexor tendons and metacarpals
Infection can track proximally
Between flexor tendons and pronator quadra- Flexor sheath infection can track proximally
tus. Thumb and SF flexor sheaths communi- into bursa
cate here

Proximal extension of FPL sheath

Communicates with SF FDS/FDP flexor tendon
sheath

NETTER’S CONCISE ORTHOPAEDIC ANATOMY 197

6 Hand • OTHER STRUCTURES

Epiphysis Synovial membrane Extensor digitorum tendon
Articular cartilage
Sagittal section Nail matrix Middle phalanx
(germinal matrix)

Nail root

Eponychium (cuticle)

Nail bed Lunula Flexor digitorum
superficialis tendo
(sterile matrix)

Body of nail

Distal phalanx Nerves Arteries Septa Fibrous tendon
Distal anterior closed space (pulp) sheath finger
Cross section
through distal Synovial (flexor tendon) sheath
phalanx of finger

Flexor digitorum profundus tendon

Palmar ligament (plate)
Articular cavity

Subungual space Body of nail
Nail bed

Minute arteries Distal phalanx

Fine nerves Fibrous septa and areolar
tissue in anterior
to neighboring digit closed space (pulp)

Dorsal branches of proper palmar Dorsal digital artery and nerve
digital arteries and nerves to dorsum
of middle and terminal phalanges

Arteries and nerves

Nutrient branch to epiphysis Proper palmar digital artery
Nutrient branches to metaphysis Proper palmar digital artery and nerve

STRUCTURE CHARACTERISTICS COMMENT

FINGERTIP

Nail Cornified epithelium If completely avulsed, consider replacing to pre-
vent eponychium and matrix adhesions

Nail bed/matrix Under eponychium and nail to edge of lunula Where nail grows (1mm a week), must be intact
Germinal Under nail, distal to lunula (repaired) for normal nail growth
Adheres to nail. Repair may prevent nail deformity.
Sterile

Pulp Multiple septa, nerves, arteries Felon is an infection of the pulp

Paronychia Radial and ulnar nail folds Common site of infection

Eponychia Proximal nail fold Common site of infection

• The digital artery is superficial/volar to the nerve proximally but runs dorsal to the nerve in the finger.
• Volar neurovascular bundle supplies the distal finger and fingertip.

198 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

MINOR PROCEDURES • Hand 6

Thumb CMC Injection Digital Block Digital block, both
1st metacarpal bone sides of base of
finger
Trapezium

Flexor Sheath Injection

Flexor tendon
sheath

FDS tendon

FDP tendon

Metacarpal

STEPS
INJECTION OF THUMB CMC JOINT
1. Ask patient about allergies
2. Palpate thumb CMC joint on volar radial aspect
3. Prepare skin over CMC joint (iodine/antiseptic soap)
4. Anesthetize skin locally (quarter size spot)
5. Palpate base of thumb MC, pull axial distraction on thumb with slight flexion to open joint. Use 22 gauge or smaller
needle, and insert into joint (if available use an image intensifier to confirm needle is in joint). Aspirate to ensure nee-
dle is not in a vessel. Inject 1-2 ml of 1:1 local (without epinephrine) /corticosteroid preparation into CMC joint. (The
fluid should flow easily if needle is in joint)
6. Dress injection site
FLEXOR TENDON SHEATH BLOCK
1. Ask patient about allergies
2. Palpate the flexor tendon at the distal palmar crease over metacarpal head/A1 pulley.
3. Prepare skin over palm (iodine/antiseptic soap)
4. Insert 25 gauge needle into flexor tendon at the level of the distal palmar crease. Withdraw needle very slightly so
that it is just outside tendon, but inside sheath. Inject 2-3ml of local anesthetic without epinephrine. (Add corticoste-
roid if injecting for trigger finger).
5. Dress injection site

DIGITAL/METACARPAL BLOCK
1. Prepare skin over dorsal proximal finger web space (iodine/antiseptic soap)
2. Insert 25 gauge needle between metacarpal necks (metacarpal block) or on either side of proximal phalanx (digital

block) in digital web space. Aspirate to ensure that needle is not in a vessel. Inject 1-2ml of local anesthetic (without
epinephrine) on both sides of the bones. Consider injecting local anesthetic dorsally over the bone as well.
3. Care should be taken not to inject too much fluid into the closed space of the proximal digit.
4. Dress injection site

NETTER’S CONCISE ORTHOPAEDIC ANATOMY 199

6 Hand • HISTORY Boxer fracture

Fractures and dislocations of thumb Fractures of metacarpal
Injury to proximal phalanx or neck commonly result
metacarpophalangeal joint of thumb from end-on blow of fist.
caused by fall with outstretched Often called street-fighter
hand on ski pole or boxer fractures

Fight bite Mallet finger

Penetration of
metacarpophalangeal
joint by tooth in fist fight

Usually caused by direct blow on extended distal
phalanx, as in baseball, volleyball

QUESTION ANSWER CLINICAL APPLICATION
1. Hand dominance Right or left
2. Age Young Dominant hand injured more often
Middle age-elderly
3. Pain Trauma, infection
a. Onset Acute Arthritis, nerve entrapments
b. Location Chronic
CMC (thumb) Trauma, infection
4. Stiffness Joints (MCPs, IPs) Arthritis
Volar (fingers) Arthritis (OA) especially in women
5. Swelling In AM, “catching” Arthritis (osteoarthritis, rheumatoid)
Catching/clicking Purulent tenosynovitis (ϩ Kanavel signs)
6. Mass After trauma
7. Trauma No trauma Rheumatoid arthritis
Trigger finger
8. Activity Fall, sports injury
9. Neurologic symptoms Open wound Infection (e.g., purulent tenosynovitis, felon, paronychia)
Sports, mechanical Trigger finger, arthritides, gout, tendinitis
Pain, numbness, tingling
Ganglion, Dupuytren’s contracture, giant cell tumor
10. History of arthritides Weakness
Multiple joints involved Fracture, dislocation, tendon avulsion, ligament injury
Infection

Trauma (e.g., fracture, dislocation, tendon or ligament injury)

Nerve entrapment (e.g., carpal tunnel), thoracic outlet
syndrome, radiculopathy (cervical)
Nerve entrapment (usually in wrist or more proximal)

Rheumatoid arthritis, Reiter’s syndrome, etc.

200 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

Rheumatoid arthritis PHYSICAL EXAM • Hand 6
Boutonniere deformity of index
finger with swan-neck deformity Osteoarthritis
of other fingers Heberden’s nodes seen in index and middle finger
distal interphalangeal joints. Bouchards nodes seen
in proximal interphlangeal joints of the ring and
small finger.

Scaphoid Median nerve compression
Ulnar nerve compression Atrophy of thenar muscles
Interosseous muscle wasting due to compression of median
from ulnar nerve compression nerve

Rotation displacement of ring
finger. All fingers should point
toward scaphoid when clenched

EXAMINATION TECHNIQUE CLINICAL APPLICATION
Gross deformity
Finger position INSPECTION Rheumatoid arthritis
Skin, hair, nail changes Fracture
Swelling Ulnar drift/swan neck, boutonniere
Rotational or angular deformity Dupuytren’s contracture, purulent tenosynovitis
Muscle wasting Fracture (acute), fracture malunion
Flexion
Rotation of digit Neurovascular disorders: Raynaud’s, diabetes,
nerve injury
Cool, hairless, spoon, etc
Osteoarthritis: Heberden’s nodes (at DIPs: #1),
DIPs Bouchard’s nodes (at PIPs)
PIPs Rheumatoid arthritis
MCPs Purulent tenosynovitis
Fusiform shape finger
Median nerve injury, CTS, C8/T1 pathology
Thenar eminence Ulnar nerve injury (e.g., cubital tunnel syndrome)
Hypothenar eminence/intrinsics

NETTER’S CONCISE ORTHOPAEDIC ANATOMY 201

6 Hand • PHYSICAL EXAM Stenosing tenosynovitis
(trigger finger)
Infections of the fingers

Paronychia Felon
Dupuytren’s contracture

Patient unable to extend affected finger. It can be
extended passively, and extension occurs with distinct
and painful snapping action. Circle indicates point of
tenderness where nodular enlargement of tendons and
sheath is usually palpable

Purulent tenosynovitis.
Four cardinal signs of Kanavel

Flexion contracture of 4th and 5th fingers (most common). 2. Fusiform swelling
Dimpling and puckering of skin. Palpable fascial nodules
near flexion crease of palm at base of involved fingers 1. Pain on 3. Slight flexion
with cordlike formations extending to proximal palm extension

4. Tenderness along tendon sheath

EXAMINATION TECHNIQUE CLINICAL APPLICATION

Skin PALPATION
Metacarpals
Phalanges and finger joints Warm, red Infection
Soft tissues Cool, dry Neurovascular compromise

Each along its length Tenderness may indicate fracture

Each separately Tenderness: fracture, arthritis
Swelling: arthritis

Thenar eminence Wasting indicates median nerve injury
Hypothenar eminence Wasting indicates ulnar nerve injury
Palm (palmar fascia) Nodules: Dupuytren’s contracture; snapping
A1 pulley with finger extension: trigger finger
Flexor tendons: along volar finger Tenderness suggests purulent tenosynovitis
All aspects of finger tip Tenderness: paronychia or felon

202 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

PHYSICAL EXAM • Hand 6

90˚ 75˚ Radial 0˚ Ulnar
20˚ rotation deviation

Extension 30˚

0˚

Flexion

90˚ 75˚ 90˚ 90˚
Range of finger flexion
Distal palmar crease Range of thumb opposition

MP joint CMC joint MP joint
PIP joint
DIP joint IP joint

Normal finger flexion is Normal thumb
composite of flexion of opposition is composite
MP, PIP, and DIP joints of movements of CMC,
and allows fingertip to MP, and IP joints.
touch distal palmar crease. Normal range is to base
of little finger.
Distal palmar
crease

EXAMINATION TECHNIQUE CLINICAL APPLICATION

MCP joint RANGE OF MOTION
PIP joint
DIP joint Finger

CMC joint Flex 90°, extend 0°, adduct/abduct 0-20° Decreased flexion if casted in extension (collateral
MCP joint ligaments shorten)
IP joint Flex 110°, extend 0° Hyperextension leads to swan neck
Opposition Flex 80°, extend 10° All fingers should point to scaphoid at full flexion

Thumb

Radial abduction: flex 50°, extend 50° Motion is in plane of palm
Palmar abduction: abduct 70, adduct 0° Motion is perpendicular to plane of the palm
In plane of palm: flex 50°, extend 0°
In plane of palm: flex 75°, extend 10° Motion is mostly at CMC joint
Touch thumb to small finger base

NETTER’S CONCISE ORTHOPAEDIC ANATOMY 203

6 Hand • PHYSICAL EXAM

Sensory testing

Median nerve C5-T1 Ulnar nerve C8-T1 Radial nerve C5-C8

Sensory distribution Sensory distribution Sensory distribution Two-point
discrimination
Finger flexion. Motor testing
FDS & FDP. Normal Abnormal
Median
nerve. C8

Thumb extension. Finger extension. Finger abduction. Anterior interosseous nerve dysfunction (paresis of flexor
EPL. Radial nerve EDC. Radial nerve Interosseous m. digitorum profundus and flexor pollicis longus muscles).
(PIN). C7 (PIN). C7 Ulnar n. T1

EXAMINATION TECHNIQUE CLINICAL APPLICATION

Radial nerve (C6) NEUROVASCULAR
Median nerve (C6-7)
Ulnar nerve (C8) Sensory

Radial nerve/PIN (C7) Dorsal thumb, web space Deficit indicates corresponding nerve/root lesion

Median nerve (C8) Radial border, index finger Deficit indicates corresponding nerve/root lesion
AIN
Motor recurrent branch Ulnar border, small finger Deficit indicates corresponding nerve/root lesion
Ulnar nerve (deep
branch) (T1) Motor

Hoffman’s Finger MCP extension Weakness ϭ Extensor digitorum or nerve lesion

Capillary refill Thumb abduction/extension Weakness ϭ APL/EPL or nerve/root lesion
Allen’s test
Doppler Finger PIP flexion Weakness ϭ FDS or corresponding nerve/root lesion
Index finger DIP flexion Weakness ϭ FDP or AIN nerve lesion
Thumb IP flexion Weakness ϭ FPL or corresponding nerve/root lesion
Thumb opposition Weakness ϭ APB, OP, 1/2 FPB or nerve lesion; (CTS)

Finger abduction Weakness ϭ Dorsal/volar interosseous or nerve lesion
Thumb adduction Weakness ϭ Adductor pollicis or nerve/root lesion

Reflex

Flick MF DIPJ into flexion Pathologic if thumb IPJ flexes: myelopathy

Vascular

Squeeze finger tip Color (blood) should return in less than 2 seconds
Occlude both radial & ulnar Hand should “pink up” if artery that was released AND
arteries, then release one arches are patent. Failure to “pink up” ϭ arterial injury
Arches, digital borders Use if presence of pulses/patent vessels is in question

204 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

Positive Froment’s sign PHYSICAL EXAM • Hand 6

When pinching a piece Elson test
of paper between thumb Normal intact central slip
and index finger, the
thumb IP joint will flex PIP joint
if the adductor pollicis
muscle is weak (ulnar Abnormal ruptured central slip
nerve paralysis).

Thumb instability test
Stress test for ruptur-
ed ulnar collateral
ligament of thumb
(gamekeeper thumb)

EXAMINATION TECHNIQUE CLINICAL APPLICATION

Profundus test SPECIAL TESTS
Sublimus test
Stabilize PIPJ in extension, flex DIPJ only Inability to flex DIP alone indicates FDP pathology
Froment’s sign
Extend all fingers, flex a single finger at PIPJ Inability to flex PIP of isolated finger indicates FDS
CMC grind test pathology
Finger instabil-
ity test Hold paper with thumb and index finger, pull If thumb IP flexion is positive, suggest adductor
Thumb paper pollicis weakness and/or ulnar nerve palsy

instability test Axial compress and rotate CMC joint Pain indicates arthritis at CMC joint of thumb

Bunnell-Littler Stabilize proximal joint, apply varus and valgus Laxity indicates collateral ligament injury
test stress
Elson test
Stabilize MCP, apply valgus stress in extension Laxity at 30°: ulnar collateral ligament injury
and 30° of flexion Laxity in extension: accessory collateral ligament
and/or volar plate injury

Extend MCPJ, passively flex PIPJ Tight or inability to flex PIPJ, improved with MCPJ
flexion indicates tight intrinsic muscles

Flex PIPJ 90° over table edge, resist P2 exten- DIPJ rigidly extending (via lateral bands) indicates
sion central slip injury (boutonnière)

NETTER’S CONCISE ORTHOPAEDIC ANATOMY 205

6 Hand • ORIGINS AND INSERTIONS

Abductor pollicis brevis Flexor pollicis brevis Muscle attachments
Abductor pollicis longus Flexor carpi ulnaris Origins
Opponens pollicis Abductor digiti minimi Insertions
Flexor carpi radialis Flexor digiti minimi brevis
Abductor pollicis Flexor carpi ulnaris
brevis Opponens digiti minimi
Flexor pollicis
brevis Volar interossei
Flexor pollicis Abductor digiti minimi
longus Flexor digiti minimi brevis

Adductor pollicis Extensor carpi Extensor carpi
Oblique head ulnaris radialis brevis
Transverse head
Flexor digitorum superficialis Extensor carpi
radialis brevis
Flexor digitorum profundus
Abductor pollicis
Palmar view longus

Dorsal interossei Extensor
pollicis
Abductor digiti brevis
minimi
Extensor
Extensor digitorum pollicis
communis (central slip) longus

Extensor digitorum
communis (terminal
tendons)

Dorsal view

CARPUS METACARPAL PHALANGES—DORSAL PHALANGES—PLANTAR

Trapezium Dorsal interosseous Proximal phalanx Proximal phalanx
Abductor pollicis brevis Palmar interosseous Ext. pollicis brevis (thumb) Abductor pollicis brevis (thumb)
Flexor pollicis brevis Adductor pollicis Dorsal interossei Flexor pollicis brevis (thumb)
Opponens pollicis Abd. pollicis longus Abductor digiti minimi Adductor pollicis (thumb)
Capitate Opponens pollicis Middle phalanx Palmar interossei
Adductor pollicis Opp. digiti minimi Extensor digitorum com- Flexor digiti minimi brevis
Hamate Flexor carpi radialis munis (central slip) Abductor digiti minimi
Flex. digiti minimi brevis Flexor carpi ulnaris Distal phalanx
Opponens digiti minimi Ext. carpi rad. longus Ext. pollicis longus Middle phalanx
Pisiform Ext. carpi rad. brevis (thumb) Flexor digitorum superficialis
Abductor digiti minimi Extensor carpi ulnaris Extensor digitorum com-
munis (terminal tendon) Distal phalanx
Flexor pollicis longus (thumb)
Flexor digitorum profundus

Lumbricals originate on flexor digitorum profundus [FDP] tendon and insert on the radial lateral bands

206 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

MUSCLES • Hand 6

Anterior (palmar) view

Radial artery and palmar carpal branch Pronator quadratus muscle
Radius Ulnar nerve
Ulnar artery and palmar carpal branch
Superficial palmar branch of radial artery Flexor carpi ulnaris tendon

Transverse carpal ligament Palmar carpal arterial arch
(flexor retinaculum) (reflected) Pisiform
Median nerve
Opponens pollicis muscle
Abductor digiti minimi muscle (cut)
Branches of median nerve Deep palmar branch of ulnar artery
to thenar muscles and to 1st and deep branch of ulnar nerve
and 2nd lumbrical muscles
Flexor digiti minimi brevis muscle (cut)
Abductor pollicis Opponens digiti minimi muscle
brevis muscle (cut) Deep palmar (arterial) arch
Palmar metacarpal arteries
Flexor pollicis Common palmar digital arteries
brevis muscle Deep transverse metacarpal ligaments

Adductor pollicis
muscle

1st dorsal
interosseous muscle

Branches from deep Lumbrical muscles (reflected)
branch of ulnar nerve
to 3rd and 4th lumbrical
muscles and to all
interosseous muscles

MUSCLE ORIGIN INSERTION NERVE ACTION COMMENT

THENAR COMPARTMENT

Abductor pollicis Scaphoid, Lateral prox. Median Palmar pronation Primary muscle in
brevis (APB) trapezium
phalanx (thumb) opposition

Flexor pollicis brevis

1. Superficial head Trans. carpal lig. Base of thumb Median Thumb MPC Muscle has dual
Proximal phalanx Ulnar flexion innervations
2. Deep head Trapezium

Opponens pollicis Trapezium Lateral thumb Median Oppose (flex/ Pronates/stabilizes
MC
abduct) thumb thumb MC

ADDUCTOR COMPARTMENT

Adductor pollicis 1. Capitate, 2nd Ulnar base of Ulnar Thumb adduc- Test function with
tion and thumb Froment’s test
1. Oblique head and 3rd MC proximal pha- MCP flexion

2. Transverse head 2. 3rd metacarpal lanx of thumb

HYPOTHENAR COMPARTMENT

Palmaris brevis [PB] Transverse carpal Skin on medial Ulnar Wrinkles skin Protects ulnar nerve
ligament [TCL] palm

Abductor digiti Pisiform (FCU Ulnar base of Ulnar SF abduction Ulnar nerve and
minimi [ADQ] tendon) prox. phalanx artery under it

Flexor digiti minimi Hamate, TCL Base of proximal Ulnar SF MCP flexion Deep to ADQ and
brevis [FDMB] phalanx of SF nerve

Opponens digiti min- Hamate, TCL Ulnar side 5th Ulnar Oppose (flex and Deep to other
imi [ODQ]
metacarpal supinate) SF muscles

• Abductor muscles are superficial; opponens muscles are deep
• Motor recurrent branch of median innervates thenar muscle and radial 2 lumbricals
• Deep branch at ulnar nerve innervates hypothenar, adductor pollicis, interossei, and ulnar 2 lumbricals

NETTER’S CONCISE ORTHOPAEDIC ANATOMY 207

6 Hand • MUSCLES Lumbrical muscles

Flexor digitorum
profundus tendons

1st and 2nd lumbrical muscles 3rd and 4th lumbrical muscles
(unipennate) (bipennate)

Camper chiasm Flexor digitorum
superficialis tendons (cut)

Interosseous muscles Ulna

Posterior Radius Anterior
(dorsal) view (palmar)
Radius Palmar interosseous view
Ulna muscles (unipennate)
23
Abductor digiti Radial artery Deep transverse 1
minimi muscle metacarpal
Abductor pollicis ligaments
brevis muscle

43 2 Dorsal
interosseous
1 muscles
(bipennate)

Tendinous slips to
extensor expansions
(hoods)

MUSCLE ORIGIN INSERTION NERVE ACTION COMMENT

INTRINSICS Extend PIP, flex Only muscles in body
MCP to insert on their own
Lumbricals 1 & 2 FDP tendons Radial lateral Median Extend PIP, flex antagonist (FDP). Pal-
(radial 2) bands MCP mar to deep trans-
Lumbricals 3 & 4 verse MC ligaments.
FDP tendons Radial lateral Ulnar
Interosseous: (medial 3) bands DAB: Dorsal ABduct
dorsal (DIO) Bipennate: each belly
Adjacent Proximal phalanx Ulnar Digit abduction has separate insertion
metacarpals and extensor Ulnar MCP flexion
expansion (lat- PAD: Palmar ADduct
Interosseous: Adjacent eral bands) Digit adduction Unipennate
palmar (PIO) metacarpals
Extensor expan-
sion (lateral
bands)

208 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

MUSCLES • Hand 6

Carpal tunnel
release

Thenar compartment Dorsal interosseous Dorsal incision 2
compartments
Adductor Hypothenar
compartment compartment
Dorsal incision 1 Palmar
interosseous
Carpal tunnel compartments
release
Transverse
carpal ligament

CONTENTS COMPARTMENT
COMPARTMENTS (10)
Thenar Abductor pollicis brevis, flexor pollicis brevis, opponens pollicis
Hypothenar Abductor digiti minimi, flexor digiti minimi brevis, opponens digiti minimi
Adductor Adductor pollicis
Palmar interosseous (3) Palmar interosseous muscles
Dorsal interosseous (4) Dorsal interosseous muscles

Incisions FASCIOTOMIES
Dorsal (1) 3 incisions (2 dorsal and 1 carpal tunnel release) can release all compartments.
Dorsal (2) Over 2nd metacarpal, dissect on both sides: release radial 2 interosseous (2 dorsal, 1 palmar)
Medial Over 4th metacarpal, dissect on both sides: release ulnar 4 interosseous (2 dorsal, 2 palmar)
Release transverse carpal ligament, then thenar, hypothenar, & adductor compartments

NETTER’S CONCISE ORTHOPAEDIC ANATOMY 209

6 Hand • NERVES

Cutaneous innervation of the hand

Anterior (palmar) view Medial cutaneous
nerve of forearm
Musculo- Lateral Flexor pollicis brevis muscle
cutaneous cutaneous Palmar (deep head only; superficial Palmar
nerve nerve of cutaneous head and other thenar mus- cutaneous
forearm branch cles supplied by median nerve) branch
Superficial branch
Radial Superficial Palmar Ulnar
nerve branch digital nerve Deep branch
branches

Median Palmar Palmaris brevis Hypothenar
nerve branch muscles
Abductor
Palmar digiti minimi
digital
branches Flexor digiti
minimi brevis
Adductor Opponens
pollicis digiti minimi
muscle
Common palmar digital nerve

Communicating branch of
median nerve with ulnar nerve

Proper palmar digital nerves
(dorsal digital nerves are
from dorsal branch)

Palmar and dorsal Dorsal branches to dorsum of
interosseous muscles middle and distal phalanges

3rd and 4th lumbrical
muscles (turned down)

BRACHIAL PLEXUS

Medial Cord

Ulnar (C[7]8-T1): Runs in forearm under FCU, on FDP. Dorsal cutaneous branch divides 5cm proximal to wrist. This
nerve continues into the dorsal aspect of the ulnar digits as dorsal digital nerves. Ulnar nerve enters Guyon’s canal,
then divides into superficial (sensory) and deep (motor) branches. The deep branch bends around the hook of the ha-
mate and runs with the deep arterial arch. The superficial branch continues into the palmar aspect of the fingers as the
palmar digital nerves.

Sensory: Dorsal ulnar hand: via dorsal cutaneous branch
Dorsal small & ring fingers: via dorsal digital branches
Ulnar proximal palm: via palmar cutaneous branch
Ulnar distal palm: via common palmar digital branches
Palmar small & ring fingers: via proper palmar digital branches

Motor: Superficial (sensory) branch
‫ ؠ‬Palmaris brevis—only muscle innervated by this branch
Deep (motor) branch: travels with deep arterial arch
• Hypothenar compartment
‫ ؠ‬Abductor digiti minimi (ADM)
‫ ؠ‬Flexor digiti minimi brevis (FDMB)
‫ ؠ‬Opponens digiti minimi (ODM)
• Adductor compartment
‫ ؠ‬Adductor pollicis
• Intrinsic muscles
‫ ؠ‬Lumbricals (ulnar two [3,4])
‫ ؠ‬Dorsal interossei (DIO)
‫ ؠ‬Palmar (volar) interossei (VIO)
• Thenar compartment
‫ ؠ‬Flexor pollicis brevis (FPB)—deep head only

210 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

NERVES • Hand 6

Posterior (dorsal) view Lateral cutaneous Musculo- Wrist and Hand: Superficial
nerve of forearm cutaneous Radial Dissection
Medial cutaneous nerve
nerve of forearm Lateral (radial) view
Posterior cutaneous Radial
Division between ulnar nerve of forearm nerve Superficial branch
and radial nerve innerva- of radial nerve
tion on dorsum of hand is Superficial branch
variable; it often aligns with and dorsal digital Medial branch
middle or 3rd digit instead branches Lateral branch
of 4th digit as shown
Dorsal digital
Ulnar Dorsal cutaneous Proper palmar Median branches of
nerve branch and dorsal digital branches nerve radial nerve
digital branches
Proper palmar Scaphoid
digital branches

Thenar Abductor pollicis brevis Palmar Dorsal
muscles cutaneous carpal
Opponens pollicis branch branch
of radial
Superficial head Communicating artery
of flexor pollicis branch of median
brevis (deep nerve with
head supplied ulnar nerve
by ulnar nerve)
Common
1st and 2nd palmar
lumbrical digital
muscles nerves

Dorsal branches to Proper
dorsum of middle palmar
and distal phalanges digital
nerves

BRACHIAL PLEXUS

Medial and Lateral Cords

Median (C[5]8-T1): Runs in forearm on FDP. Palmar cutaneous branch branches proximal to the carpal tunnel. The
median nerve enters the carpal tunnel. The motor recurrent branch exits distal to transverse carpal ligament (TCL)
and supplies the thenar muscles. Anatomic variants include exit through (at risk in carpal tunnel release) or under the
TCL. The remainder of the nerve is sensory and supplies the palmar radial 31⁄2 digits.

Sensory: Palm of hand: via palmar cutaneous branch
Volar thumb, IF, MF, radial RF: via palmar digital branches
Dorsal distal thumb, IF, MF, radial RF: via proper palmar digital branch

Motor: Motor (recurrent) branch
• Thenar compartment
‫ ؠ‬Abductor pollicis brevis (APB)
‫ ؠ‬Opponens pollicis
‫ ؠ‬Flexor pollicis brevis (FPB)—superficial head only
• Intrinsic muscles
‫ ؠ‬Lumbricals (radial two [1,2])

Posterior Cord

Radial (C5-T1): Superficial branch runs under brachioradialis to wrist, then bifurcates in medial & lateral branches that
supply the dorsal hand & thumb web space. They continue as dorsal digital branches to the dorsal fingers.

Sensory: Dorsal radial hand: via superficial branch
Dorsal proximal thumb, IF, MF, radial RF: via dorsal digital branches

Motor: None (in hand)

NETTER’S CONCISE ORTHOPAEDIC ANATOMY 211

6 Hand • ARTERIES

Radial artery Ulnar artery and nerve

Superficial palmar Transverse carpal ligament
branch of radial artery (flexor retinaculum)

Recurrent (motor) Deep palmar branch of ulnar artery
branch of median and deep branch of ulnar nerve
nerve to thenar
muscles Superficial branch of ulnar nerve
Adductor pollicis
muscle Common flexor sheath
(ulnar bursa)
Proper digital Superficial palmar (arterial) arch
nerves and
arteries to Common palmar digital nerves
thumb and arteries

Branches of median Communicating branch of
nerve to 1st and 2nd median nerve with ulnar nerve
lumbrical muscles Proper palmar digital nerves
and arteries

Branches of proper palmar digital
nerves and arteries to dorsum of
middle and distal phalanges

Radial artery Ulnar artery and nerve

Superficial palmar branch of radial artery Palmar carpal branches of
radial and ulnar arteries
Deep palmar (arterial) arch
Deep palmar branch of
Princeps pollicis artery ulnar artery and deep
branch of ulnar nerve
Proper digital arteries and
nerves of thumb Branches to
Distal limit of superficial hypothenar muscles
palmar arch (Kaplan’s line)
Superficial branch
Radialis indicis artery of ulnar nerve

Palmar metacarpal arteries Deep palmar branch of
Common palmar digital arteries ulnar nerve to 3rd and
4th lumbrical, all inter-
Proper palmar digital arteries osseous, adductor pollicis,
Proper palmar digital nerves from and deep head of flexor
median nerve pollicis brevis muscles

Proper palmar digital
nerves from ulnar nerve

COURSE BRANCHES COMMENT/SUPPLY

• Radial artery: divides at wrist into superficial branch, which anastomoses with the superficial palmar arch. The
deep branch runs thru the bellies of the 1st dorsal interosseous muscle & terminates as the deep palmar arch.

• Ulnar artery: divides at wrist into a deep branch, which anastomoses with the deep palmar arch. The superficial
branch terminates as the superficial palmar arch.

DEEP PALMAR ARCH

Runs volar to the bases Princeps pollicis Continuation of deep branch of radial artery
of the metacarpals. It is Radialis indicis Supplies radial IF; may branch from deep arch
proximal to the superfi- Proper digital arteries of thumb (2) Two terminal branches of bifurcated princeps pollicis
cial arch. Anastomoses with common digital arteries
Palmar metacarpal (3)

SUPERFICIAL PALMAR ARCH

Located at Kaplan’s line; Proper palmar digital artery to SF First branch off arch; supplies ulnar small finger
distal to the deep arch Common palmar digital (3) In 2nd-4th web spaces, each bifurcates
Runs on radial & ulnar borders of digits
Proper palmar digital

• Superficial arch supplies most of the hand/fingers. It is dominant 2⁄3 of the time. This arch is complete 80% of the time.
• Deep arch supplies the thumb (& radial IF). It is usually the nondominant arch. This arch is complete 98% of the time.
• The arches are codominant 1⁄3 of the time. Allen’s test determines if arch is complete (but not which is dominant).
• Arteries are volar to the nerves in the palm, but cross to become dorsal to the nerves in the fingers.

212 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

Osteoarthritis DISORDERS • Hand 6

Rheumatoid arthritis

Section through distal interphal- Radiograph of distal interphalangeal Radiograph shows cartilage thinning at proximal
angeal joint shows irregular, hyper- joint reveals late-stage degenerative interphalangeal joints, erosion of carpus and
plastic bony nodules (Heberden’s changes. Cartilage destruction and wrist joint, osteoporosis, and finger deformities
nodes) at articular margins of distal marginal osteophytes (Heberden’s
phalanx. Cartilage eroded and joint nodes)
space narrowed

Late-stage degenerative changes in Boutonniere deformity of index finger with
carpometacarpal articulation of thumb swan-neck deformity of other fingers

DESCRIPTION Hx & PE WORKUP/FINDINGS TREATMENT

OSTEOARTHRITIS

• Loss of articular cartilage Hx: Elderly or hx of injury XR: OA findings: 1. NSAIDs
• Due to wear or posttraumatic Pain: worse w/activity joint space loss, 2. Steroid injection
• DIPJ #1 (Heberden’s nodes) PE: Nodule/deformity, tender- osteophytes, scle- 3. Arthrodesis/fusion
• PIPJ #2 (Bouchard’s nodes) ness, decreased ROM rosis, subchondral 4. Arthroplasty
cysts

MUCOUS CYST

• Ganglion cyst from arthritic Hx: Mass near a joint XR: Joint arthritis 1. Excision of cyst and
joint (DIPJ #1) PE: Mass, ϩ/Ϫ tenderness associated osteophyte

RHEUMATOID ARTHRITIS

• Autoimmune disease attacks HX: Pain and stiffness (worse XR: Joint destruc- 1. Medical management
synovium and destroys joints in AM) tion 2. Synovectomy (1 joint)
PE: Deformities (ulnar drift, LABS: RF, ANA, ESR, 3. Tendon transfer/repair
• MCPJ #1 swan neck, boutonniere) CBC, uric acid 4. Arthrodesis/arthroplasty
• Multiple deformities develop

SWAN NECK DEFORMITY

• FDS insertion/volar plate injury Hx: Injury or RA XR: Shows bony 1. Early: splint
• Traumatic or assoc. with RA PE: Deformity: flexed DIPJ, deformity 2. Late: surgical release
• Lateral bands subluxate dor- injury hyperextended PIPJ
and reconstruction
sally, hyperextends PIPJ 3. Arthrodesis

BOUTONNIERE DEFORMITY

• Central slip (EDC) and triangu- Hx: Traumatic injury or RA XR: Shows bony 1. Early: splint PIPJ in
lar ligament injury PE: Deformity: flexed PIPJ, ϩ deformity extension
Elson’s test (inability to ex-
• Traumatic or assoc. with RA tend the flexed PIPJ) 2. Reconstruct lateral
• Lateral bands subluxate volarly, bands and central slip

hyperflexes PIPJ 3. Arthrodesis/arthroplasty

NETTER’S CONCISE ORTHOPAEDIC ANATOMY 213

6 Hand • DISORDERS

Tenosynovitis Paronychia infection
A
A
A A

B Eponychium elevated
BB from nail surface

C Sporotrichosis Horseshoe abscess

Tenosynovitis of the middle finger. Treated with zigzag volar
incision. Tendon sheath opened by reflecting cruciate pulleys.
Fine plastic catheter inserted for irrigation. Lines of incision
indicated for tendon sheaths of other fingers (A); radial and
ulnar bursae (B); and Parona’s subtendinous space (C)

Felon

Cross section shows division Begins as small nodule and From focus in thumb spreads
of septum in finger pulp spreads to hand, wrist, fore- through radial and ulnar bursae
arm (even systemically). and tendon sheath of little finger,

with rupture into Parona’s sub-
tendinous space

DESCRIPTION Hx & PE WORKUP/FINDINGS TREATMENT

• Tendon sheath infection PURULENT FLEXOR TENOSYNOVITIS 1. Diagnosis Ͻ24hr: IV anti-
• Usu. from puncture/bite biotics, close observation
• May spread proximally Hx: Pain and swelling XR: Plain films. r/o (I&D if no improvement)
PE: Kanaval signs (4): foreign body, air
into deep spaces or 1. Flexed position LABS: CBC, ESR, CRP 2. Diagnosis Ͼ24hr: irriga-
Parona’s space (horse- 2. Fusiform swelling tion and debridement of
shoe abscess) 3. Pain w/passive extension sheath ϩ IV antibiotics
4. Flexor sheath tenderness
• Deep infection/abscess 1. Incise and drain (must re-
in pulp of finger FELON lease septum in pulp)

• Staph. aureus #1 Hx: Pain & swelling XR: Usually not needed 2. Antibiotics (IV vs oral)
PE: Pointing abscess, edema,
• Infection of nail fold erythema, ϩ/Ϫ drainage 1. Early: warm soaks
• #1 hand infection 2. I&D and oral antibiotics
• Etiology: nail biting, hang PARONYCHIA / EPONYCHIA 3. Partial nail excision

nails Hx: Pain & swelling XR: Usually not needed 1. Incise & drain, IV abx
PE: Erythema, tenderness, 2. Wound care/dressing
• Infection in deep spaces ϩ/Ϫ drainage
or tissues (e.g., thenar, changes as needed
hypothenar, Parona’s DEEP SPACE INFECTIONS
[horseshoe]) Potassium iodine solution
Hx: Pain & swelling XR: Usually normal
• Fungal (Sporothrix s.) in- PE: Edema, erythema, tender- MR/CT: May help if
fection from plants/roses ness, fluctuance, ϩ/Ϫ drain- diagnosis is unclear
age
• Spreads via lymphatics
SPOROTRICHOSIS

Hx: Rash/discoloration XR: Usually not needed
PE: Early: single nodule
Late: multiple nodules/rash

214 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

DISORDERS • Hand 6

Deep space infections Infection of
midpalmar space
secondary to
tenosynovitis
of middle finger.
Focus is infected
puncture wound
at distal crease.
Line of incision
indicated

Infection of thenar space from
tenosynovitis of index finger
due to puncture wound.

Dupuytren’s Stenosing Tenosynovitis (Trigger Finger)
Disease

Partial excision Inflammatory thickening of fibrous sheath (pulley) of
of palmar fascia flexor tendons with fusiform nodular enlargement of
with care to avoid both tendons. Broken line indicates line for incision
neurovascular bundles. of lateral aspect of pulley

DESCRIPTION Hx & PE WORKUP/FINDINGS TREATMENT

• Usually dominant hand BITES: HUMAN/ANIMAL 1. Td & rabies prophylaxis
• “Fight bite”ϭ fist to mouth #1 if indicated
• Bacteria: Strep., Staph. a. Hx: Bite, pain & swelling XR: Hand series: rule
PE: Puncture wound or out foreign body 2. I&D, wound care
Human: Eikenella corr. laceration, edema, ϩ/Ϫ (e.g., tooth) or air 3. IV antibiotics (ampicillin/
Animal: Pasteurella mult. drainage, erythema (local in tissues/joint
or tracking proximally) LABS: CBC, ESR, CRP sulbactam)
• Tight/thickened A1 pulley en-
traps flexor tendon STENOSING TENOSYNOVITIS (TRIGGER FINGER) 1. Splint, occupational rx
2. Corticosteroid injection
• Associated with DM, RA, age Hx: 40ϩ, pain, snapping XR: Usually normal
• Congenital form in pediatrics or locking (esp. in AM) MR: Not needed, PE into tendon sheath
PE: Tender flexor sheath, is diagnostic 3. A1 pulley release
• Contracture of palmar fascia snapping with flex./ext.
• Myofibroblasts create thick 1. Early (mass, no contrac-
DUPUYTREN’S DISEASE ture): reassurance
cords of type III collagen
• Associated with northern Euro- Hx: Usually male, 40ϩ, XR: Usually normal 2. Late (contracture): surgi-
c/o hand mass MR: Not needed if di- cal excision of cords
peans (AD), DM, EtOH PE: Nodule in palm, ϩ/Ϫ agnosis is clear. May
contracture of MCPJ or be useful if etiology 1. Aspiration/puncture
• Ganglion-type cyst of the PIPJ of mass is unclear. 2. Surgical excision if
flexor tendon sheath
RETINACULAR CYST recurrent
• Most common hand mass
Hx: Small volar mass XR: Usually normal
PE: Firm, “pea”-size nod- MR: Not needed
ule, does not move
w/tendon

NETTER’S CONCISE ORTHOPAEDIC ANATOMY 215

6 Hand • PEDIATRIC DISORDERS

Syndactyly

Incision lines
(preferred method)

Dorsal aspect Palmar aspect

H

G
D

C

F
B

AE

DH
G

C

F B
Full-thickness

A graft

E

Suture lines

DESCRIPTION EVALUATION TREATMENT

• Failure of differentiation of finger tissue SYNDACTYLY 1. Should wait approximately 1yr, then
• Most common congenital hand surgically separate fingers
Hx: Fingers are connected
anomaly PE: Fingers are connected either 2. Careful incision planning and skin
• Complete (to finger tip) vs incomplete to tip or incompletely down the grafts improve results
• Simple (soft tissue) vs complex (bone) finger
XR: Will determine if bones are 1. Nonoperative: stretching, splint
• Congenital finger flexion anomaly fused (complex) 2. Functionally debilitating contrac-
• Usually PIPJ of small finger
• Type 1 (infants), type 2 (adolescents) CAMPTODACTYLY ture: surgical release/tendon
• Etiology: abnormal lumbrical or FDS transfer
Hx: Finger flexed. Noticed at birth
insertion or during adolescent growth 1. Mild: no treatment
PE: Inability to fully extend joint 2. Functional deficit: surgical
• Deviation of finger in coronal plane XR: Shows flexion, bones typi-
• Radial deviation of small finger #1 cally normal correction/realignment osteotomy
• Etio: delta-shaped middle phalanx
CLINODACTYLY

Hx/PE: Deviation of finger, cos-
metic and functional complaints
XR: Shows delta-shaped middle
phalanx

216 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

PEDIATRIC DISORDERS • Hand 6

Polydactyly

Postaxial Preaxial
Congenital constriction band syndrome

DESCRIPTION EVALUATION TREATMENT

DUPLICATE THUMB (PREAXIAL POLYDACTYLY) 1. Surgical reconstruction to
obtain stable thumb. Gener-
• An extra thumb or portion thereof Hx/PE: Extra thumb or portion of thumb ally, retain ulnar thumb/
• Wassel classification (7 types): XR: Will show bifid or extra phalanges de- structures & reconstruct
pending on which type of duplication radial side (e.g., type 4)
Type 4 is most common
• Autosomal dominant or sporadic 1. Type I: Small thumb: no
• Associated with some syndromes treatment

THUMB HYPOPLASIA 2. Types II-IIIA: Reconstruction
3. Types IIIB-V (no CMCJ): am-
• Partial or complete absence of Hx/PE: Small to completely absent thumb
thumb XR: Range of small, shortened, or absent putation & pollicization
bones (phalanges, metacarpal, trapezium).
• Blauth classification: Types I– V 1. Complete amputations if
• Treatment based on presence of Evaluate for presence of the CMC joint needed

CMC joint 2. Release/excise bands,
• Associated with some syndromes Z-plasty as needed for skin
coverage
CONSTRICTION BAND SYNDROME

• Constrictive bands lead to digit Hx/PE: Short/truncated fingers with bands at
necrosis or diminished growth/ level of diminished growth
development. XR: Small, shortened, or absent phalanges

• Nonhereditary

NETTER’S CONCISE ORTHOPAEDIC ANATOMY 217

6 Hand • SURGICAL APPROACHES

Incision Volar approach to finger
site
Incision
may be
extended

A1
C1
A2

C2

Digital
nerve

Flexor Digital artery
tendons
Flexor A3
Grayson’s sheath C3
ligament
A4
Cleland’s
ligament Digital Midlateral approach to finger
nerve
Incision
Digital site
artery
Flexor
sheath

Joint
ligaments

Flexor
digitorum
superficialis

Flexor
digitorum
profundus

Flexor
tendons

Digital
nerve
Digital
artery

USES INTERNERVOUS DANGERS COMMENT
PLANE
• Flexor tendons (repair/explore)
• Digital nerves FINGER: VOLAR APPROACH
• Soft tissue releases
• Infection drainage No planes • Digital artery • Make a “zigzag” incision connecting
• Digital nerve finger creases
• Phalangeal fractures • Flexor tendon
• Neurovascular bundle is lateral to the
tendon sheath.

FINGER: MID-LATERAL APPROACH

No planes • Digital nerve • Soft tissues are thin; capsule can be
• Digital artery incised if care is not taken.

218 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

Topographic Anatomy CHAPTER 7
Osteology
Radiology Pelvis
Trauma
Joints 220
History 221
Physical Exam 225
Origins and Insertions 227
Muscles 232
Nerves 234
Arteries 235
Disorders 237
Surgical Approaches 238
241
244
246
247

7 Pelvis • TOPOGRAPHIC ANATOMY External oblique muscle
Linea alba
Rectus abdominis muscle Semilunar line
Iliac crest
Anterior superior Umbilicus
iliac spine (ASIS) Inguinal ligament
Superficial circumflex iliac vein Hip joint
Pubic tubercle
Superficial epigastric veins Greater trochanter of femur
Pubic symphysis

Iliac crest Gluteus medius muscle
Erector spinae muscle Sacrum
Posterior superior iliac spine Gluteus maximus muscle
Greater trochanter of femur
Sacroiliac joint
Gluteal fold
Intergluteal (natal) cleft

Ischial tuberosity

STRUCTURE CLINICAL APPLICATION
Iliac crest
Site for contusion of lilac crest (“hip pointers”)
Anterior superior iliac spine Common site for autologous bone graft harvest

Symphysis pubis Origin of sartorius muscle. An avulsion fracture can occur here.
Inguinal ligament Lateral femoral cutaneous nerve (LFCN) courses here and can be entrapped.
Landmark used for measuring the “Q” angle of the knee
Greater trochanter
Erector spinae muscles Site of osteitis pubis; uncommon cause of anterior pelvic pain
Posterior superior iliac spine
Sacroiliac joint External iliac artery becomes femoral artery here; femoral pulse can be palpated just
Ischial tuberosity inferior to the ligament in the femoral triangle.

Tenderness can indicate trochanteric bursitis.

Overuse and spasm are common causes of lower back pain (LBP).

Site of bone graft harvest in posterior spinal procedures.

Degeneration of joint can cause lower back pain (LBP).

Avulsion fracture (hamstring muscles) or bursitis can occur here.

220 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

OSTEOLOGY • Pelvis 7

Base of sacrum Superior articular Sacral canal
process
Ala (lateral Lumbosacral
part) articular surface Superior
articular process
Dorsal surface
Ala (wing) Pelvic surface
Promontory

Promontory

Sacral part of pelvic
brim (linea terminalis)

Sacral hiatus

Transverse Anterior (pelvic) Median sagittal section
ridges sacral foramina

Apex of sacrum Facets of superior
articular processes

Anterior Transverse process
of coccyx
inferior Coccyx
Auricular surface
view

Pelvic surface Sacral tuberosity

Median sacral crest Posterior Lateral sacral crest Posterior
sacral foramen Median sacral crest sacral
Sacral canal foramina
Intervertebral Intermediate sacral crest
foramen Sacral cornu
Sacral hiatus (horn)

Anterior (pelvic) Coccygeal cornu
sacral foramen (horn)

Coronal section Dorsal surface Transverse process
through S1 foramina of coccyx

Posterior superior view

CHARACTERISTICS OSSIFY FUSE COMMENTS

PELVIS

• Combination of 3 bones (two innominate bones & sacrum) and 3 joints (two sacroiliac joints & symphysis pubis)

• The pelvis has no inherent stability. It requires ligamentous support for its stability.

• Two portions of pelvis divided by pelvic brim/iliopectineal line
‫ ؠ‬False (greater) pelvis—above the brim, bordered by the sacral ala and iliac wings
‫ ؠ‬True (lesser) pelvis—below the brim, bordered by the ischium and pubis

SACRUM

• 5 vertebra are fused Primary 8wk (fetal) 2-8yr • Transmits weight from spine to pelvis
• 4 pairs of foramina Body • Nerves exit through the sacral foramina
2-8yr
(left and right) Arches 2-8yr (anterior & posterior)
• Ala (wing) expands laterally Costal elements • Ala is common site for sacral fractures
• Sacral canal opens to hiatus 20yr • Sacral canal narrows distally before
Secondary 11-14yr
distally opening to sacral hiatus
• Kyphotic (approx. 25°), • Segments fuse to each other at puberty

the apex is at S3

COCCYX

• 4 vertebrae are fused Primary arch 7-8wk 1-2yr • Is attached to gluteus maximus and
• Lack features of typical (fetal) 7-10yr coccygeal m.

vertebrae Body • Common site for “tailbone” fracture

NETTER’S CONCISE ORTHOPAEDIC ANATOMY 221

7 Pelvis • OSTEOLOGY

Lateral view Intermediate zone
Tuberculum
Anterior Iliac crest
Outer lip
Gluteal Inferior Ilium
lines Wing (ala) of ilium (gluteal surface) Ischium
Posterior Pubis

Anterior superior iliac spine

Posterior superior Anterior inferior iliac spine
iliac spine

Posterior inferior Acetabulum
iliac spine Lunate surface
Margin (limbus) of acetabulum
Greater sciatic notch Acetabular notch/condyloid fossa
Body of ilium Superior pubic ramus
Ischial spine
Pubic tubercle

Lesser sciatic notch Obturator crest Intermediate zone Iliac crest
Body of ischium
Ischial tuberosity Inferior pubic Inner lip
ramus
Obturator foramen

Coxal Ilium Ramus of ischium Iliac tuberosity
bone (8th week)
Ischium Anterior superior Posterior
(16th week) iliac spine superior
Pubis iliac spine
(16th week) Wing (ala) of ilium (iliac fossa) Auricular
surface
Anterior inferior iliac spine (for sacrum)
Posterior
Arcuate line inferior
Iliopubic eminence iliac spine
Superior pubic ramus Greater sciatic notch

Pecten pubis Ischial spine
(pectineal line)
Pubic tubercle Body of ilium
Lesser sciatic notch
Symphyseal
surface Body of ischium
Obturator groove
Ischial tuberosity
Inferior pubic ramus
Ramus of ischium
Obturator
foramen

Triradiate cartilage

CHARACTERISTICS OSSIFY FUSE COMMENTS

• 3 bones (ilium, ischium, INNOMINATE BONE • Iliac crest is common site for both
pubis) fuse to become one tricortical and cancellous bone
bone at triradiate cartilage Primary 2-6mo to acetabulum graft harvest
in acetabulum (one in each 15yr
body) • Contusion to iliac crest known as
• Ilium: body, ala (wing) “hip pointer”
• Pubis: inferior & superior Secondary 15yr All fuse 20yr
Iliac crest • Iliac crest ossification used to de-
rami Triradiate termine skeletal maturity (Risser
• Ischium: body & tuberosity Ischial tuberosity stage)
• Acetabulum: “socket” of hip AIIS
Pubis • Multiple iliac spines serve as ana-
joint, has 2 walls (anterior & tomic landmarks & muscle inser-
posterior) & notch/condyloid tion sites (ASIS, AIIS, PSIS, PIIS)
fossa inferiorly. Articular car-
tilage is horseshoe shaped • Acetabulum: 45° oblique orienta-
tion, 15° anteverted

222 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

OSTEOLOGY • Pelvis 7

Iliac crest Inner lip Sacral L3 Transverse processes of lumbar vertebrae
Intermediate zone promontory L4
Outer lip L5 Iliac tuberosity
Tuberculum Iliac crest

Anterior superior iliac spine Coccyx Wing (ala) of ilium
Anterior inferior iliac spine Pubic arch
Sacrum
Iliopubic eminence
Superior pubic ramus Greater sciatic notch
Obturator foramen
Pubic tubercle Arcuate line

Inferior pubic ramus Ischial spine
Inferior pubic ligament
Lesser sciatic notch
Greater trochanter
of femur
Pecten pubis
(pectineal line)

Pubic symphysis
Ischial tuberosity
Lesser trochanter of femur

STRUCTURE ATTACHMENTS/RELATED STRUCTURES COMMENT

Anterior superior LANDMARKS AND OTHER STRUCTURES OF THE PELVIS
iliac spine (ASIS)
Sartorius • LFCN crosses the ASIS & can be compressed there
Anterior inferior Inguinal ligament • Sartorius can avulse from it (avulsion fx)
iliac spine (AIIS) Transverse & int. oblique abdominal m. • Landmark to measure Q angle of the knee

Posterior superior Rectus femoris • Rectus femoris can avulse from it (avulsion fx)
iliac spine (PSIS) Tensor fasciae latae
Arcuate line Iliofemoral ligament (hip capsule)
Gluteal lines
Gtr. trochanter Posterior SI ligaments • Excellent bone graft site
Lesser trochanter Marked by skin dimple
Ischial tuberosity
Pectineus • Aka pectineal line. Strong, weight-bearing region
Ischial spine
3 lines: anterior, inferior, posterior • Separate origins of gluteal muscles
Lesser sciatic
foramen SEE ORIGINS/INSERTIONS • Tender with trochanteric bursitis

Greater sciatic Iliacus/psoas muscle • Tendon can snap over trochanter (“snapping hip”)
foramen
SEE ORIGINS/INSERTIONS • Excessive friction ϭ bursitis (weaver’s bottom)
Sacrotuberous ligaments • Hamstrings can avulse (avulsion fx)

Coccygeus & levator ani attach
Sacrospinous ligaments

Short external rotators exit: • Obturator internus is landmark to posterior column
Obturator externus • Obt. externus not seen in posterior approach
Obturator internus

Structures that exit: • Piriformis muscle is the reference point
1. Superior gluteal nerve • Superior gluteal nerve and artery exit superior to the
2. Superior gluteal artery
3. Piriformis muscle piriformis
4. Pudendal nerve • POP’S IQ is a mnemonic for the nerves (structures)
5. Inferior pudendal artery
6. Nerve to the Obturator internus that exit inferior to the piriformis (medial to lateral)
7. Posterior Cutaneous nerve of thigh (see page 243)
8. Sciatic nerve • Sciatic nerve (especially peroneal division) may exit
9. Inferior gluteal nerve pelvis above or through the piriformis as an anatomic
10. Inferior gluteal artery variation
11. Nerve to Quadratus femoris

NETTER’S CONCISE ORTHOPAEDIC ANATOMY 223

7 Pelvis • OSTEOLOGY

Lateral view Iliac wing Medial view

Greater sciatic Posterior column
notch Anterior column
Lesser sciatic
notch Acetabulum Greater sciatic notch
Ischial Anterior wall Ischial spine
tuberosity Superior pubic ramus Lesser sciatic notch

Obturator Pecten pubis Ischial tuberosity
foramen (pectineal line)
Pubic tubercle Inferior Obturator
pubic ramus foramen
Posterior superior
quadrant (“safe zone”) ASIS

Anterior superior
quadrant

Center of acetabulum

Posterior inferior
quadrant

Anterior inferior
quadrant

STRUCTURE RELATED STRUCTURES COMMENT

ACETABULAR COLUMNS

Anterior (iliopubic) 1. Superior pubic ramus Involved in several different fracture patterns
2. Anterior acetabular wall
3. Anterior iliac wing
4. Pelvic brim

Posterior (ilioischial) 1. Ischial tuberosity Involved in several different fracture patterns
2. Posterior acetabular wall
3. Greater & lesser sciatic notches

ACETABULAR ZONES

Zones defined by 2 lines: 1. ASIS to center of acetabulum, 2. perpendicular to line 1
Structures can be injured when screws are placed in these zones (e.g., acetabular cups)

Anterior superior External iliac artery & vein Do not put screws in this zone

Anterior inferior Obturator nerve, artery, vein Do not put screws in this zone

Posterior superior Sciatic nerve This is the safe zone
Superior gluteal nerve, artery, vein

Posterior inferior Sciatic nerve This is a secondary safe zone. Safe screw placement
Inferior gluteal nerve, artery, vein can be achieved with care if necessary.
Internal pudendal nerve, artery, vein

224 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

Sacroiliac joint RADIOLOGY • Pelvis 7

Ilioishial line Radiograph, AP pelvis
(posterior column)
Sacrum
Anterior wall Iliopectineal line
(of acetabulum) (anterior column)
Teardrop
Pubic symphysis Roof
(of acetabulum)
Posterior wall
(of acetabulum)

RADIOGRAPH TECHNIQUE FINDINGS CLINICAL APPLICATION
AP (anteroposterior) Screening for fractures (sacral,
AP, IR feet 15°, beam 6 radiographic lines:
directed at midpelvis 1. Iliopectineal (ant. column) pelvic acetabular, proximal fe-
2. Ilioischial (post. column) mur), use ATLS protocol; dys-
Pelvic inlet view AP, beam 45° caudal 3. Radiographic “teardrop” plasia, degenerative joint
4. Acetabular roof (“dome”) disease/arthritis
5. Ant. acetabulum rim/wall
6. Post. acetabulum rim/wall Pelvic ring fractures: shows
posterior displacement or
Sacroiliac joints, pelvic brim/ symphysis widening
pubic rami, sacrum Pelvic ring fractures: shows su-
perior displacement of hemi-
Pelvic outlet view AP, beam 45° cephalad Iliac crest, symphysis pubis, pelvis
sacral foramina
Acetabulum fx: anterior column,
Oblique/Judet views Beam at affected hip: posterior wall
Obturator oblique Elevate affected hip 45° Obturator foramen Acetabulum fx: posterior
column, anterior wall
Iliac oblique Elevate unaffected hip Iliac crest, sciatic notches
CT 45° Fractures, especially sacrum
OTHER STUDIES & acetabulum
Axial, coronal, & sagittal Articular congruity, fx fragments Labral tears, tumors, stress fx
Tumors, infection
MRI Sequence protocols Soft tissues: muscles, cartilage
Bone scan All bones evaluated

NETTER’S CONCISE ORTHOPAEDIC ANATOMY 225

7 Pelvis • RADIOLOGY

Sacrum Inlet view Outlet view Iliac crest
Iliac oblique (Judet) Obturator oblique (Judet)
Sacroiliac L5
joint
Sacrum
Femoral
head Sacro-
Superior iliac
pubic joint
ramus
Femoral
Pubic head
symphysis
Inferior
Inferior pubic
pubic ramus
ramus

Iliac crest Posterior wall
(acetabulum)
Posterior
column Anterior
column
Anterior wall
(acetabulum) Obturator
foramen

CT pelvis CT pelvis

Iliac crest Sacrum Sacroiliac Fovea Posterior wall Femoral head
joint (acetabulum) Acetabulum

Anterior wall
(acetabulum)

226 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

TRAUMA • Pelvis 7

Vertical sacral fracture, Denis classification

Zone Zone Zone
1 2 3

Ala (wing)

Promontory

Sacral part of pelvic
brim (linea terminalis)

Anterior Pelvic surface
inferior
view

Sacral fractures

Coccyx fracture

Transverse fracture of the sacrum that is minimally displaced Fracture usually requires no treatment other than
care in sitting; inflatable ring helpful. Pain may
persist for a long time.

DESCRIPTION EVALUATION CLASSIFICATION TREATMENT

SACRAL FRACTURE

• Mechanism: elderly—fall; Hx: Trauma (fall or By direction of fracture • Minimally displaced/stable:
young—high energy (e.g., accident), pain ϩրϪ • Vertical. Denis: ‫ ؠ‬Nonoperative
MVA) neurologic sx
PE: Palpate spine & sa- ‫ ؠ‬Zone 1: lateral to • Displaced/unstable:
• Isolated injuries rare, usually crum. Complete neuro foramina ‫ ؠ‬Closed reduction and per-
assoc. w/pelvis or spine fx exam including rectal cutaneous fixation
exam. ‫ ؠ‬Zone 2: through ‫ ؠ‬Open reduction, internal
• Nerve root injury very com- XR: AP pelvis, lateral foramina fixation
mon sacrum
CT: Necessary for ‫ ؠ‬Zone 3: medial to • Nerve injury: decompression
• Plain XR identifies Ͻ50% of diagnosis & preop foramina
fractures planning
• II. Transverse
• Easily missed & difficult to • III. Oblique
treat, can lead to chronic • Complex: “U” or “H”
pain
shape

COMPLICATIONS: Nerve root injury & cauda equina syndrome, esp. zone 3 fractures; nonunion/malunion, chronic pain

NETTER’S CONCISE ORTHOPAEDIC ANATOMY 227

7 Pelvis • TRAUMA

Classification of pelvic fractures (Young and Burgess)

Anteroposterior Compression Type I Anteroposterior Compression Type II
(APC-I) (APC-II)

Anteroposterior Compression Type III
(APC-III)

DESCRIPTION EVALUATION CLASSIFICATION TREATMENT

PELVIC RING FRACTURE

• Mechanism: high-energy Hx: High-energy Young & Burgess: • ATLS protocol. Treat
blunt trauma (e.g., MVA) trauma, pain ϩ/Ϫ AP Compression (APC) life-threatening injuries
neurologic sx I. Ͻ2.5cm pubic diastasis
• Multiple associated injuries: PE: Inspect perineum • Pelvic hemorrhage: pel-
GI, GU, extremity fxs, neuro- for open injury. LE ϩ 1 or 2 pubic rami vis compression (e.g.,
logic, vascular, head (LC) may be malrotated. fractures sheet) or external fixa-
Pelvic “rock.” Rectal II. Ͼ2.5cm diastasis ϩ an- tion to reduce pelvic
• Very high morbidity, usually & vaginal exams for terior SI injury, but verti- volume
due to uncontrolled hemor- associated injuries. cally stable
rhage (venousϾarterial Complete neuro exam III. Complete ant. (symphy- • Diverting colostomy for
bleeding) esp. w/ APC3 incl. rectal tone & bul- sis) & post. (SIJ) disrup- open injury or any
(“open book”) fxs bocavernosus re- tion. Unstable communication
flexes. Lateral Compression (LC) w/open bowel
• Open fracture has higher XR: AP pelvis, inlet and I. Sacral compression ϩ
morbidity and complication outlet views are es- ipsilateral rami fracture • Nonoperative: WBAT
rate. sential. II. LC1 ϩ iliac wing fx or for LC1, APC1, ramus
CT: Especially useful to post. SIJ injury. Vertically fx
• Stability of fx based on liga- define sacral/SIJ in- stable
ment disruption (esp. ST, SS, jury III. LC 2 with contralateral • Operative for LC2 & 3;
posterior SI) AGRAM: If hemody- APC3 (“windswept” APC 2 & 3, vertical
namically unstable af- pelvis) stress
• Avulsion of iliolumbar ter pelvic stabilization; Vertical Shear ‫ ؠ‬Anterior: ORIF of
ligament/L5 transverse consider embolization SIJ & ST/SS ligament dis- symphysis
process suggests unstable fx of artery ruption ϩ rami fxs. ‫ ؠ‬Post: 1. ORIF of iliac
Vertically unstable wing and sacral frac-
• Lateral compression most tures; 2. SI screws
common for dislocated SIJ
‫ ؠ‬LC1: posterior-directed
force
‫ ؠ‬LC2: anterior-directed force

COMPLICATIONS: Hemorrhage (venousϾarterial [internal pudendal a. Ͼ superior gluteal a.]), neurologic injuries (L5 root
at risk w/SI screws), malunion/nonunion, chronic pain (esp. at SIJ) and functional disability, infection, thromboembolism

228 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

TRAUMA • Pelvis 7

Classification of Pelvic Fractures (Young and Burgess)

Lateral Compression Type I Lateral Compression Type II Lateral Compression Type III
(LC-I) (LC-II) (LC-III)

Pelvic rami fractures

Vertical shear

Fracture of pelvis without Fracture of ipsilateral pubic and ischial ramus
disruption of pelvic ring requires only symptomatic treatment with short-
term bed rest and limited activity with walker-
Avulsions or crutch-assisted ambulation for 4 to 6 weeks.

Avulsion of
anterior superior
iliac spine due to
pull of sartorius
muscle

Avulsion of ischial Avulsion of anterior
tuberosity due to inferior iliac spine
pull of hamstring due to pull of rectus
muscles femoris muscle

DESCRIPTION EVALUATION CLASSIFICATION TREATMENT

PELVIC FRACTURE—OTHER • Isolated fxs: treat with
limited rest, WBAT
• Mechanism: Low-energy Hx: Pain, esp. with WB Isolated fxs: Inferior or supe-
trauma (fall, sports injury, PE: TTP at bony site rior pubic rami, iliac wing/ • Avulsion fx: most treated
etc) XR: AP, inlet/outlet crest nonoperatively. Reattach
views Avulsions: ASIS (sartorius), if widely displaced.
• Stable isolated fractures, CT: Often not needed, AIIS (rectus femoris), ischial
pelvic ring not disrupted can determine dis- tuberosity (hamstrings)
placement
• Can occur in osteopenic
bone

COMPLICATIONS: Malunion/nonunion, chronic pain/disability, thromboembolism

NETTER’S CONCISE ORTHOPAEDIC ANATOMY 229

7 Pelvis • TRAUMA

Acetabulum—Elementary Fractures

Fracture of posterior wall Fracture of posterior column Wedge fracture of anterior wall

Fracture of anterior column Transverse fracture

DESCRIPTION EVALUATION CLASSIFICATION TREATMENT

ACETABULAR FRACTURE

• Mechanism: high- Hx: High-energy trauma, Letournel & Judet: • Reduce hip if dislocated
energy blunt trauma pain, inability to WB
(e.g., MVA); fem. head PE: LE may be malrotated. • Elementary fractures (traction if necessary to
into acetabulum Inspect skin for Morel- ‫ ؠ‬Posterior wall
Lavalle lesion. Neuro ‫ ؠ‬Posterior column maintain reduction)
• Fracture pattern deter- exam. ‫ ؠ‬Anterior wall
mined by force vector XR: AP pelvis, obturator & ‫ ؠ‬Anterior column • Nonoperative: NWB for
& position of femoral iliac obliques (Judet ‫ ؠ‬Transverse
head at impact views) are essential. Roof 12wk
arc angle: center of head • Associated fractures ‫ ؠ‬Ͻ2mm articular dis-
• Multiple associated in- to fx (Ͻ45° is WB ) ‫ ؠ‬Post. column & post.
juries: GI, GU, extrem- CT: Essential to accurately placement
ity fractures define fx (size, impaction, wall ‫ ؠ‬Roof arc angle Ͼ45°
articular involvement, LB ) ‫ ؠ‬Transverse & post. wall ‫ ؠ‬Posterior wall fx Ͻ20-
• Surgical approaches: & do preop planning ‫ ؠ‬T type
‫ ؠ‬Kocher-Langenbeck: ‫ ؠ‬Ant. column and post. 30%
posterior fxs (PW, PC,
transverse, T type) hemitransverse • Operative: ORIF, NWB 12wk
‫ ؠ‬Ilioinguinal: anterior ‫ ؠ‬Both columns ‫ ؠ‬2mm articular displace-
fxs (AW, AC/HT, both ment
columns) ‫ ؠ‬Posterior wall Ͼ40%
‫ ؠ‬Irreducible fx/dx
‫ ؠ‬Marginal impaction
‫ ؠ‬Loose bodies in hip joint

• XRT for HO prophylaxis

COMPLICATIONS: Posttraumatic arthritis, nerve injury (sciatic nerve), postsurgical (heterotopic ossification [HO], sciatic
nerve injury, bleeding), malunion/nonunion, infection (assoc. with Morel-Lavalle lesion), thromboembolism

230 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

TRAUMA • Pelvis 7

Acetabulum—Associated Fractures

Posterior column/posterior wall Transverse/posterior wall T-shaped fracture

Anterior column/posterior hemi transverse Both columns

Open reduction internal fixation acetabular fracture

Posterior column fracture. Anterior column fracture. Transverse fracture.
Repair with plate and lag screw Repair with plate and long screws Repair with plate and lag screw

NETTER’S CONCISE ORTHOPAEDIC ANATOMY 231

7 Pelvis • JOINTS

Iliolumbar ligament
Iliac crest
Supraspinous ligament

Posterior superior iliac spine
Posterior sacroiliac ligaments
Posterior (dorsal) sacral foramina

Greater sciatic foramen Anterior
longitudinal
Anterior superior iliac spine ligament
Sacrospinous ligament
Sacrotuberous ligament

Lesser sciatic foramen Iliac Iliolumbar
Acetabular margin fossa ligament

Ischial tuberosity

Tendon of long head of
biceps femoris muscle

Iliac crest

Anterior sacroiliac ligament

Deep Posterior Sacral promontory
sacrococcygeal
Superficial ligaments Greater sciatic foramen

Anterior superior iliac spine

Lateral sacrococcygeal Linea Sacrotuberous ligament
ligament terminalis
Sacrospinous ligament
Posterior view
Anterior inferior iliac spine

Ischial spine

Arcuate line

Lesser sciatic foramen

Iliopectineal Iliopubic eminence

line Superior pubic ramus

Pecten pubis

(pectineal line)

Anterior view Anterior sacral (pelvic) foramina

Obturator foramen Pubic
Inferior pubic ramus tubercle Coccyx
Anterior sacrococcygeal ligaments
Pubic symphysis

LIGAMENTS ATTACHMENTS COMMENTS

SACROILIAC

• This is a gliding joint. It has minimal rotational motion during gait. There should be no vertical motion in the normal joint.
• Vertical stability is essential; the body weight is transmitted through this joint.
• Articular surface (located inferiorly in articulation) covered with: sacrum (articular cartilage), ilium (fibrocartilage)

Posterior sacroiliac Posterolateral sacrum to posteromedial ilium Strongest in pelvis: key to vertical stability
‫ ؠ‬Short sacroiliac Oblique orientation: sacrum to PSIS & PIIS Resists rotational forces
‫ ؠ‬Long sacroiliac Vertical orientation: sacrum to PSIS Resists vertical forces.
Blends with sacrotuberous ligament

Anterior sacroiliac Anterior sacrum to anterior ilium Weaker than posterior; resists rotational
forces

Interosseous Sacrum to ilium Adds support to anterior & posterior ligaments

PELVIC STABILITY

Rotational stability Tranverse/horizontal orientation Short posterior SI, anterior SI, sacrospinous,
iliolumbar ligaments

Vertical stability Longitudinal/vertical orientation Long posterior SI, sacrotuberous, lumbosacral
ligaments

232 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

JOINTS • Pelvis 7

Median (sagittal) section Body of L5 vertebra
False pelvis
Iliac Intermediate zone Lumbosacral (L5—S1) intervertebral disc
crest Inner lip Sacral promontory
Greater sciatic foramen
Iliac fossa (wing True pelvis
of ilium) Ischial spine
Sacrospinous ligament
Anterior superior Lesser sciatic foramen
iliac spine Sacrotuberous ligament
Coccyx
Arcuate line

Anterior inferior
iliac spine

Iliopubic eminence
Obturator canal
Superior pubic ramus
Pecten pubis
(pectineal line)

Pubic tubercle Ischial tuberosity
Symphyseal
surface Body of L4 vertebra
Obturator membrane Iliac crest

Lateral view Wing (ala) of ilium
Posterior superior iliac spine (gluteal surface)

Median sacral crest Body of ilium
Anterior superior
Posterior inferior iliac spine iliac spine
Anterior inferior
Posterior sacroiliac ligament iliac spine
Greater sciatic foramen
Sacrospinous ligament Acetabulum

Posterior and lateral Acetabular labrum
sacrococcygeal ligaments Lunate (articular) surface
Acetabular notch
Sacrotuberous ligament
Ischial spine Transverse acetabular
ligament

Superior pubic ramus

Lesser sciatic foramen Pubic tubercle

Ischial tuberosity Obturator canal

Obturator membrane Inferior pubic ramus

LIGAMENTS ATTACHMENTS COMMENTS

PUBIC SYMPHYSIS

• Anterior articulation of two hemipelves. Articulating surfaces are covered with hyaline cartilage.
• Fibrocartilage disc between two pubic bones in the joint

Superior pubic Both pubic bones superiorly (& anteriorly) Strongest supporting ligament

Arcuate pubic Both pubic bones inferiorly Muscle attachments also support inferiorly

OTHER LIGAMENTS

Sacrospinous Anterolateral sacrum to spinous process Resists rotation, divides sciatic notches

Sacrotuberous Posterolateral sacrum to ischial tuberosity Resists vertical forces, provides vertical stability

Iliolumbar L4 & L5 transverse process to posterior Avulsion fracture sign of unstable pelvic ring injury
iliac crest

Lumbosacral L5 transverse process to sacral ala Anterior support, assists in providing vertical stability

NETTER’S CONCISE ORTHOPAEDIC ANATOMY 233

7 Pelvis • HISTORY

Anteroposterior compression pelvic
fracture of pelvis (open book fracture)

Forceful frontal impact causes
anteroposterior compression
of pelvis

Lateral compression injury
pelvic (overlapping pelvis)

Caused by forceful blow
to side of pelvis

QUESTION ANSWER CLINICAL APPLICATION
1. Age
Young Ankylosing spondylitis
2. Pain Middle aged–elderly Sacroiliitis, decreased mobility
a. Onset
b. Character Acute Trauma: fracture, dislocation, contusion
c. Occurrence Chronic Systemic inflammatory, degenerative disorder
Deep, non-specific Sacroiliac etiology, infection, tumor
3. PMHx Radiating To thigh or buttock, SI joint, L-spine
4. Trauma In/out of bed, on stairs Sacroiliac etiology
Adducting legs Symphysis pubis etiology
5. Activity/work
6. Neurologic symptoms Pregnancy Laxity of ligament in SI joint causes pain
7. History of arthritides
Fall on buttock, twist injury Sacroiliac joint injury
High velocity: MVA, fall Fracture, pelvic ring disruption

Twisting, stand on one-leg Sacroiliac etiology

Pain, numbness, tingling Spine etiology, sacroiliac etiology

Multiple joints involved SI involvement of RA, Reiter’s syndrome, ankylosing
spondylitis, etc

234 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

PHYSICAL EXAM • Pelvis 7

With palpation

Ischial bursitis
(deep pain and tenderness
over ischial tuberosity)

Hip pointer With palpation
Palpate illiac
crest for tenderness

Sacroiliitis
(deep pain and tenderness
over sacroiliac joint)

EXAM/OBSERVATION TECHNIQUE CLINICAL APPLICATION

INSPECTION

Skin Discoloration, wounds Recent trauma

ASIS’s/iliac crests Both level (same plane) If on different plane: leg length discrepancy, sacral torsion

Lumbar curvature Increased lordosis Flexion contracture
Decreased lordosis Paraspinal muscle spasm

PALPATION

Bony structures Standing: ASIS, pubic & Unequal side to side ϭ pelvic obliquity: leg length discrepancy
iliac tubercles, PSIS
Lying: iliac crest, “Hip pointer”/contusion, fractures
ischial tuberosity Ischial bursitis (“weaver’s bottom”), avulsion fx

Soft tissues Sacroiliac joint Sacroiliitis
Inguinal ligament Protruding mass: hernia
Femoral pulse & nodes Diminished pulse: vascular injury; palpable nodes: infection
Muscle groups Each group should be symmetric bilaterally

RANGE OF MOTION

Forward flexion Standing: bend forward PSISs should elevate slightly (equally)

Extension Standing: lean backward PSISs should depress (equally)

Hip flexion Standing: knee to chest PSIS should drop but will elevate in hypomobile SI joint
Ischial tuberosity should move laterally; will elevate in hypomobile
SI joint

NETTER’S CONCISE ORTHOPAEDIC ANATOMY 235

7 Pelvis • PHYSICAL EXAM Rectal examination

Trendelenburg test Rectal examination for sphincter function and perianal
Left: patient demon- sensation. Gross blood indicates pelvic fracture
strates negative communicating with colon.
Trendelenburg test
of normal right hip.
Right: positive test
of involved left hip.
When weight is on
affected side, normal
hip drops, indicat-
ing weakness of left
gluteus medius
muscle. Trunk shifts
left as patient attempts
to maintain balance

Vaginal examination Bulbcavernosus reflex test

EXAM/OBSERVATION TECHNIQUE CLINICAL APPLICATION

Iliohypogastric nerve (L1) NEUROVASCULAR
Ilioinguinal nerve (L1)
Genitofemoral nerve Sensory
Lateral femoral cutane-
ous nerve (L2-3) Suprapubic, lat butt/thigh Deficit indicates corresponding nerve/root lesion
Pudendal nerve (S2-4)
Inguinal region Deficit indicates corresponding nerve/root lesion
Femoral (L2-4)
Inferior gluteal nerve Scrotum or mons Deficit indicates corresponding nerve/root lesion
N. to quad. femoris
Superior gluteal nerve Lateral hip/thigh Deficit indicates corresponding nerve/root lesion (e.g., meralgia
paresthetica)
Reflex
Perineum Deficit indicates corresponding nerve/root lesion
Pulses
Motor
Pelvic rock
SI stress test Hip flexion Weakness ϭ iliopsoas or corresponding nerve/root lesion
Trendelenburg sign
External rotation Weakness ϭ gluteus maximus or nerve/root lesion
Patrick (FABER)
External rotation Weakness ϭ short rotators or corresponding nerve/root lesion
Meralgia
Rectal and vaginal Abduction Weakness ϭ glut. med./min or nerve/root lesion

Other

Bulbocavernosus Finger in rectum, squeeze or pull penis (Foley)/clitoris; anal
sphincter should contract

Femoral pulse Diminished pulse abnormal

SPECIAL TESTS

Push both iliac crests Instability/motion indicates pelvic ring injury

Press ASIS & iliac crests Pain in SI could be SI ligament injury

Standing: lift one leg Flexed side: pelvis should elevate; if pelvis falls, abductor or
(flex hip) gluteus medius (superior gluteal n.) dysfunction

Flex, Abduct, ER hip, Positive if pain or LE will not continue to abduct below other
then abduct more leg; SI joint pathology

Pressure medial to ASIS Reproduction to pain, burning, numbness ϭ LFCN entrapment

Especially after trauma Gross blood indicates trauma communicating with those organs

236 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

ORIGINS AND INSERTIONS • Pelvis 7

Iliacus muscle Origin of psoas major muscle Origins
from sides of vertebral bodies, Insertions
Sartorius muscle intervertebral discs and
transverse processes (T12-L4) Gluteus
Rectus femoris medius muscle
Direct head Piriformis muscle
Indirect head Gluteus
Pectineus muscle minimus muscle
Obturator internus
and superior and Adductor longus muscle Tensor fasciae
inferior gemellus latae muscle
muscles Adductor brevis muscle
Sartorius muscle
Piriformis Gracilis muscle
muscle Obturator Rectus femoris
Gluteus externus muscle
minimus muscle muscle Obturator
Adductor externus muscle
Vastus lateralis magnus muscle
muscle Quadratus Gluteus
femoris medius muscle
Iliopsoas muscle Quadratus
muscle Gluteus femoris muscle
Iliopsoas muscle
Vastus medialis maximus Gluteus
muscle muscle maximus muscle
Vastus intermedius Superior gemellus muscle Vastus
muscle lateralis muscle
Inferior gemellus muscle Adductor
magnus muscle
Quadratus femoris muscle
LINEA ASPERA
Obturator internus muscle
Vastus lateralis
Adductor magnus muscle Vastus intermedius
Vastus medialis
Biceps femoris (long head) Biceps femoris (SH)
and semitendinosus muscles
Gluteus maximus
Semimembranosus muscle Adductor magnus
Adductor brevis
PUBIC RAMI GREATER TROCHANTER ISCHIAL TUBEROSITY Adductor longus
Pectineus
Pectineus ORIGINS
Adductor longus
Adductor brevis Semimembranosus
Adductor magnus* Semitendinosus
Gracilis Biceps femoris (LH)
Obturator internus Adductor magnus*
Obturator externus ISCHIUM
Quadratus femoris
*Has two origins Inferior gemellus

INSERTIONS

Gluteus medius (posterior)
Gluteus minimus (anterior)
Quadratus femoris (inferior)
Obturator externus (fossa)
SHORT EXTERNAL ROTATORS
Piriformis
Superior gemellus
Obturator internus
Inferior gemellus

NETTER’S CONCISE ORTHOPAEDIC ANATOMY 237

7 Pelvis • MUSCLES

L1 Quadratus lumborum
L2 muscle
L3 Psoas minor muscle
L4 Psoas major muscle
L5 Transversus abdominis
muscle
Anterior Internal oblique muscle
inferior External oblique muscle
iliac spine
Iliacus muscle
Pubic tubercle Pubic symphysis
Urethra Anterior superior iliac spine
Piriformis muscle
Rectum Coccygeus (ischiococcygeus)
muscle
Ischial spine
Inguinal ligament (Poupart’s)

Obturator internus muscle

Rectococcygeus muscle

Opening for femoral vessels
Levator ani muscle

Lesser trochanter of femur

Abductors Note: Arrows indicate direction
(gluteus medius of action of iliopsoas muscle.
and
minimus muscles) Adductors

MUSCLE ORIGIN INSERTION NERVE ACTION COMMENT

HIP FLEXORS

Psoas major T12-L5 vertebrae Lesser trochanter Femoral Flex hip Covers lumbar
plexus
Psoas minor T12-L1 vertebrae Iliopubic eminence L1-ventral Assists in hip Weak—present in
ramus flexion 50% of people
Iliacus Iliac fossa/sacral ala Lesser trochanter Femoral Flex hip Covers ant. ilium

Also see muscles of the thigh/hip in Chapter 8.

238 NETTER’S CONCISE ORTHOPAEDIC ANATOMY

Superficial dissection Iliac crest MUSCLES • Pelvis 7
Gluteal aponeurosis over
Gluteus medius muscle Deeper dissection
Gluteus minimus muscle

Gluteus maximus muscle

Piriformis muscle
Sciatic nerve

Sacrospinous ligament
Superior gemellus
muscle

Obturator internus
muscle
Inferior gemellus
muscle
Sacrotuberous ligament
Quadratus femoris muscle

Ischial tuberosity

Greater trochanter

MUSCLE ORIGIN INSERTION NERVE ACTION COMMENT

Tensor fas- HIP ABDUCTORS A plane in anterior
ciae latae approach to hip
Gluteus Iliac crest, ASIS Iliotibial band/ Superior Abducts, flex, Trendelenburg gait if
medius proximal tibia gluteal IR thigh muscle is out
Gluteus Works in conjunction
minimus Ilium b/w ant. and Greater trochan- Superior Abducts, IR with medius
post. gluteal lines ter (posterior) gluteal thigh
Gluteus Must be split in poste-
maximus Ilium b/w ant. and Greater trochan- Superior Abducts, IR rior approach to hip
Obturator inf. gluteal lines thigh Inserts at start point for
externus ter (anterior) gluteal IM nail

Piriformis HIP EXTENSORS AND EXTERNAL ROTATORS Used as landmark for
sciatic nerve
Superior Ilium, dorsal sacrum ITB, gluteal tu- Inferior Extend, ER Detached in posterior
gemellus berosity (femur) gluteal thigh approach to hip
Obturator Exits through lesser
internus Ischiopubic rami, ob- Trochanteric Obturator ER thigh sciatic foramen
Inferior ge- Detached in posterior
mellus turator membrane fossa approach to hip
Quadratus Ascending br. medial
femoris Short External Rotators circumflex artery
under muscle
Anterior sacrum Superior greater N. to ER thigh

trochanter piriformis

Ischial spine Medial greater N. to obtura- ER thigh
trochanter tor internus

Ischiopubic rami, ob- Medial greater N. to obtura- ER, abduct
tor internus thigh
turator mem. trochanter

Ischial tuberosity Medial greater N. to quadra- ER thigh
trochanter tus femoris

Ischial tuberosity Intertrochanteric N. to quadra- ER thigh
crest tus femoris

NETTER’S CONCISE ORTHOPAEDIC ANATOMY 239