hand/wrist osteology

radius angulation

slightly volarly 10 degrees, and ulnarly 25 degrees

proximal row of carpals

scaphoid, lunate, triquetrum, pisiform

distal row of carpals

trapezium, trapezoid, capitate, hamate

scaphoid

proximal surface: convex

responsible for placing the first digit anterior to the plane of the palm

most commonly fractured bone in the hand, with problems healing

lunate

most frequently dislocated carpal

proximally convex, distally concave

pisiform

sits on triquetrum

FCU tendon encases this before inserting on hook of hamate

trapezium

forms CMC joint with 1st MC

capitate

axis for ulnar and radial deviation

stable bone

hamate

FCU tendon insertion

creates tunnel of guyon between pisiform and hook of hamate

ulnar n. compression here- “bikers palsy”

metacarpals

concave base, convex head

contain tubercles for collateral ligaments (ECU attachment on thumb)

phalanges

concave base, convex head

proximal/distal phalanx concave- assists in “longitudinal arch”

wrist joint consists of

radiocarpal and midcarpal

wrist joint DoF

2 DoF- flexion/extension, RD/UD

wrist joint flexion/extension

sagittal plane, ML axis

flexion: 0-80, extension: 0-70

* volar/ulnar angulation of articular surfaces allows greater ROM in flexion

wrist joint UD/RD

frontal plane, AP axis

RD: 0-20, UD: 0-35

* volar/ulnar angulation of articular surfaces allows greater ROM in UD

CMC joint 1

trapezium to first MC

2 DoF- flexion/extension, abduction/adduction

CMC flexion/extension

frontal plane, AP axis

flexion: 0-45, extension: 0

CMC abduction/adduction

sagittal plane, ML axis *and opposition, reposition (non-volitional)

abd: 0-80, add: 0

opposition involves __ degrees of thumb rotation

45-60

CMC joint 2-5

no volitional motion, minimal between hamate, capitate, and trapezoid.

• allow shape of transverse arch of the hand to change

thumb MCP joint

condyloid

1 DoF- flexion/extension BUT abd/add can occur

thumb MCP flexion/extension plane and norms

frontal plane, AP axis

flexion: 0-60, extension: 0

MCP joints 2-5

2 DoF- flexion/extension, abduction/adduction

• passive long axis rotation available due to ligamentous laxity

mcp joint flexion/extension

sagittal plane, ML axis

flexion: 0-90, extension: 45 (passive 90)

* MCP range of flexion increases moving towards digit 5

digit __ has the greated abduction/adduction

2

in MCP joints 2-5, passive extension

greatly exceeds active

IP joints

hinge joint

1 DoF- flexion/extension

IP joint flexion/extension

sagittal plane, ML axis

DIP flexion: 0-70-90, extension: 0-30 active

PIP flexion: 0-100, extension: 0?

thumb IP joint flexion/extension

frontal plane, AP axis

flexion: 0-80

RC joint arthro

scaphoid and lunate with radius and disc

convex carpal bones moving on concave radius

flexion: volar roll, dorsal glide

extension: dorsal roll, volar glide

MC joint arthro flexion/extension

proximal carpal bones with distal carpal bones

convex distal carpal bones moving on concave proximal carpal bones

flexion: volar roll, dorsal glide

extension: dorsal roll, volar glide

RCL

radial styloid- scaphoid, trapezium, transverse carpal ligament

• resists UD (like APL, EPL, EPB)

UCL

ulnar styloid- pisiform/triquetrum

• resists RD (with ECU)

  • part of ulnocarpal complex

palmar ligamentous complex

distal radius- scaphoid, lunate, triquetrum, capitate.

• important for wrist joint stability

  • limit wrist EXTENSION

dorsal ligamentous complex

posterior distal radius- scaphoid, lunate, triquetrum

• restricts FLEXION

properties of intercarpal bones

• all possess synovial cavities

• have joint capsules

• linked by interosseous ligaments

  • less vascular, slower to heal

scapholunate ligament

stabilizes scaphoid

lunotriquetral ligament

stabilizes lunate and triquetrum

functional motion of wrist joint

10 degrees flexion, 35 degrees extension

RC/MC arthro UD/RD

convex proximal carpal row on concave radius

convex capitate moving on concave proximal row

RD: radial roll

UD: ulnar roll

• glide not typically referenced

close pack position for wrist

full extension

CMC joint 2-5 arthro

will not describe arthro, but they are important for transverse arch of hand

• increased mobility of 4/5- may assist in opposition (5)

  • small motion helps form palmar arches that allow cupping

intercarpal motion

translatory motion between bases of MCs 2-5

palm proper

distal and middle palmar crease

digito palmar crease

crease at MCP

interdigital cleft

webbing between fingers

thenar eminence

flexor retinaculum, palmaris longus, radial pulse

anatomical snuffbox

EPL, EPB, APL

• base: CMC joint thumb, radial artery, radial styloid

transverse arch

formed by concavity anteriorly of carpal bones. continuous with transverse arch at MC heads

longitudinal arches

• arch of middle finger, concave anteriorly with keystone at MCP joint

• arch of index used with opposition

oblique arches

arches formed by thumb with opposition. includes

• thumb to index

• thumb to pinky

carpal tunnel

carpal bones form anterior, concave gutter. transverse carpal ligament spans gutter. medial border= pisiform, hook of hamate, lateral border= tubercle of trapezium/scaphoid

• holds finger flexor tendons, median nerve, FPL

MCP joint 2-5 arthro flexion/extension

concave base moving on a convex head

• concave base is much smaller, volar plate acts like a hinge to increase contact

flexion: volar roll, volar glide

extension: dorsal roll, dorsal glide

volar plate functions

• increase contact between joint surfaces

• prevent premature bone on bone contact in flexion

MCP flexion is limited by

dorsal muscles, extensor mechanism, collateral ligaments

MCP extension is limited by

palmar muscles, joint capsule

MCP adduction is limited by

contact with adjacent digit

extended MCP joint abd/add are limited by

interossei

flexed MCP joint abd/add are limited by

collateral ligaments

close pack position for MCP joint

70-90 degrees flexion

loose pack position for MCP joint

30 degrees flexion

IP volar plate

serves to enhance contact of small base with large head

IP collateral ligaments

restrict VALGUS and VARUS strain at IP

IP anterior capsular ligament

stabilizes volar surface

• at PIP- check rein ligament, limits EXTENSION

IP joint arthro

concave base moving on convex head

flexion: volar roll, volar glide

extension: dorsal roll, dorsal glide

thumb IP function

same manner as 2-5; 1 DoF. slight medial rotation with IP flexion due to medial condyle being slightly more distal

close pack position for IP joints

25 degrees of flexion

thumb MCP arthro

concave proximal base of phalanx moving on convex distal head of 1st MC

flexion: ulnar roll, ulnar glide

extension: radial roll, radial glide

close pack position for thumb MCP joint

full flexion (active to 60)

ligaments of 1st CMC joint

• anterior oblique

• UCL

• first intermetacarpal

• posterior oblique

• RCL

1st CMC abduction/adduction arthro

convex MC moves on concave trapezium

axis: MC

abduction: volar roll, dorsal glide

adduction: dorsal roll, volar glide

1st CMC flexion/extension arthro

concave MC moving on convex trapezium

axis: trapezium

flexion: ulnar roll, ulnar glide

extension: radial roll, radial glide

close pack position for 1st CMC joint

opposition, end range abduction

loose pack position for 1st CMC joint

mid range abduction

opposition involves

abduction, flexion, internal rotation

reposition involves

extension, adduction, external rotation