Anatomy of the Hand

KHALID AYOUB03/03/03

TOPICS• Osteology

• Arthrology

• Extensor tendon

• Flexor tendon

• Nerve supply

• Blood supply

• Common pathological conditions

Osteology

Carpus:

• Mostly articular

• No tendon insertion

• Intrinsic Ligaments

• Shape

P

R

Osteology

Carpus:• Mostly articular• No tendon insertion• Intrinsic Ligaments• Shape• Ossification

P

R

P

<11

24

5

56

6

16

ARTHROLOGY

A). Radiocarpal joint; Radius Scaphoid

Lunate

TFC Triquetrum

ARTHROLOGY

Extrinsic Ligaments

1. Radio-scapho-lunate

(Lig. Of Testut)

2. Radial collateral

3. Palmar radiocarpal;

- Radio-scapho-capitate

- Radio- lunate

4. Radio-luno-triquetral

>>

ARTHROLOGY

5. Palmar Ulnocarpal : Ulno-lunate

Ulno-triquetral

6. Ulnar collateral

7. Dorsal radiocarpal = Dorsal radio-

triquetral

8. . Tranverse carpal Lig

>>

ARTHROLOGY

B) Distal radio-ulnar joint• Stabilised by TFCC:

1. Articular disc

2. Meniscal homologue

3. UCL

4. Palmar Ulnocarpal Lig

5. Dorsal & Ulnar RU Lig

6. Extensor carpi ulnaris sheath.

>>

ARTHROLOGY

C). Intercarpal Joints

Supported by Intrinsic Ligaments &

Shape

D) Pisiform articulation

E) Midcarpal Joint; Between the

proximal and distal carpal rows

>>

ARTHROLOGY

Distal Row

Proximal Row

ARTHROLOGY

F) Metacarpo-Phalangeal Joint

• Ellipsoid joints

• Volar plate

• Collateral lig

• Deep transvers MC Lig

MC

PH

ARTHROLOGY

G). Interphalangeal joint

• Hinge joint

• Volar plate

• Collateral Lig

• Accessary Lig

EXTENSOR APPARATUS

A. Wrist• Extensor Retinaculum

• 6 compartments

EXTENSOR APPARATUS

B. Hand• EDC

• EDM

• EI

EXTENSOR APPARATUS

C. MP Joints

• Interosseous M.

• Common Extensor Tendon

• Sagital band

• Lateral Band/Tendon

• Transversr/Oblique I. L.

• Lumbrical M.

>>

EXTENSOR APPARATUS

D. Finger IP Joint

• Central slip

• Lateral slip

• Transverse Retinacular Lig

• Oblique Retinacular Lig

>>

Swan neck deformityCauses1. Long extensor overactivity• Mallet deformity (1o)• Exterinsic spasticity• Intrinsic tightness2. Failure of the volar stabilisation PIP J

(Mallet deformity 2o)

• Volar plate insufficiency• FDS insufficincy• Joint laxity

Boutonniere deformity

1. Rupture of the central slip

2. Volar dislocation of the lateral band

3. More efficient pull of the lateral band on the DIP J

Carpal Tunnel

• From distal radius to

MC bases

• Radial wall; Scaphoid,

trapezium

• Ulnar wall; triquetrum,

pisiform, hamate

• Floor: Lunate, capitate,

proximal MC

• Roof: Flexor Retinaculum

Carpal Tunnel

Componants of the roof:

1. Deep forearm fascia

2. Transverse carpal lig: -

- Scaphoid tubercle

- Trapezium ridge

- Pisiform

- Hamate hook

3. Conjoined aponeurosis

between thenar & hypothen.

Carpal Tunnel• Over:- Ulnar nerve and artery(Guyon)

- Palmar cutaneous br. of Median N.

- Palmar cutaneous br. of Ulnar N.

• Contents:

-Tendon X 9

- Median Nerve (on the

radiopalmar aspect of

the tunnel and dorsal

or dorsoradial to PL

PALM

• Palmar aponeurosis

PALM

Palmar Spaces

PALM

• Deep Palmar abscess

PALM

• Synovial Sheath

& Bursa

FINGERS

• Superficial layer• Ligaments

FINGERSCross-section

FINGER FLEXOR

• FDS• FDP• Synovial flexor sheath

• Fibrous flexor sheath pulley system

- Annulus

- Cruciate

FINGER FLEXOR

NAIL

• Nail plate: - Body

- Root• Nail bed:

- Sterile matrix

- Germinal matrix• Eponychiam• Labia ungues

MUSCLES ACTION

Muscle Function Nerve supply

EDFinger extension (MP joint)

Post. Inteross. N

Dorsal InterossFinger Abduction

Flex MP+ext IPUlnar

Palmar InterossFinger adduction Flex MP+ext IP

Ulnar

Lumbricals Flex MP+ext IP Median + Ulnar

Palmaris longus Flexion wrist/finger/ Median

Thumb Opposition

Complex motion made by;

• Thumb Abd … APB

• Thumb pronation ….APB

• Flexion CMC & MP

Mov>>>

Ulnar nerve • C7,8,T1• Forearm: FCU & Ulnar half FDP Palmar & Dorsal Cut branches• Wrist: In Guyon canal (on Flexor Retin.)• Hand: Superficial Br Deep Br: - Hypothenar - Inteross - Add. P - Two ulnar lumbrical

Ulnar Nerve Dysfunction

• Low lesion: (Below elbow) Loss innervation to the hand

small muscles only

+ Preserve forearm innervation (Ulnar FDP)

= Sever ulnar Claw Hand deformity

Ulnar Nerve Dysfunction

• High lesion (At elbow or above)

Loss innervation below elbow (including FDP)

= less sever ulnar claw hand deformity

Ulnar paradox

Median Nerve

• Roots: C6,7,8,T1• Elbow: - PT, FCR,PL, FDS• Forearm: Anterion interosseous branch; [FDP (radial), FPL, PQ]• Wrist: Palmer cutaneous branch (5 cm

proximal to wrist crease between PL & FCR)

• Hand: -3 Thenar m. (APB, FPB,OP) - 2 radial lumbricals - 3 ½ radial fingers

Median Nerve Dysfunction

Level of injury of main trunk

1. Below wrist >>>> APB

(Simian Hand)

2. Mid-forearm>> palm sensation

3. Upper forearm >> Pinch test>

Anterion interosseous palsy

4. Elbow and above >> Check FDS

Redial Nerve• Roots: C5,6,7,8,T1

• Above elbow: Muscular = Br., BR, ECRL

• Elbow:

1. Superficial terminal br. = sensory to hand

2. Deep terminal br. (Post. Inteross) >>

ECRB, Supinator

• Forearm:

- Deep terminal (Post. Inteross) br. >>> ED, EDM, ECU, APL, EPB, EPL, EI

Redial Nerve Dysfunction• Wrist >> Check sensation• Forarm: Check for post. Inteross nerve

palsy >>>>> EPL, EI, ED (no sensory loss)• Elbow and above: Wrist extension

SENSORY DISTRIBUTION

1. Ulnar N.

2. Median N

3. Radial N.

Blood Supply1. Ulnar A.

• Radial to FCU

• Forms the superficial palmar arch ?with superficial palmar br. of radial artery

• Gives 4 common palmar digital art.

• Fingers: dorsal to the nerve

Blood Supply2. Radial A.

• Radial to FCR

• Beneath APL …. Floor of

ASB

• Forms the Deep palmar arch

with deep br. of ulnar ar. 1

cm proximal to Superficial

arch

Scaphoid

• Dorsal carpal br. supply the scaphoid dorso-ditally

• Two thirds …. Throughout the length

• 20% ….. Only in the waist

• 13% …. Only in distal 1/3

Scaphoid

• Pedicled vascularised

bone graft

• Arterial supply of

dorsal distal radius

• 1,2

intercompartmental

supraretinacular artery

Basic Function1. Precision pinch

Basic Function

2. Pulp pinch: Pinch Dynamometer (2-5 kg)

Basic Function

3. Key pinch: Pinch Dynamometer (6-10 kg)

Basic Function

4. Chuck grip:

Basic Function

5. Hook grip

Basic Function

6. Span grasp:

Basic Function

7. Power grip

Basic Function

8. Flat hand:

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