Chapter 1: Clinical Anatomy

Intrinsic tightness test

• Test PIP flex with MP in ext and in flex (+) if PIP flex improves with MP flexed (intrinsics on slack)

Bouvier test

• Tests if PIPJ and extensor mechanism is working • Place MP in slight flexion and see if IPs extend- if so, extensor mechanism and PIPJ capsule are working normally • Can use MP block orthosis to improve function

Linburg's Sign

*Thumb IPJ flexion causes IF DIPJ flexion in 30% people *Due to adhesions in carpal tunnel between FPL & IF FDP *Linburg's SYNDROME is when this connection causes pain/aggravation with act

Lumbrical innervation

1-2 medial n C8 T1 3-4 deep branch of ulnar n C8 T1

Berretini anastomosis

Communication between ulnar 4th common digital nerve and median 3rd common digital nerve

Terminal tendon tenotomy

Cut terminal tendon to restore DIP flex in chronic boutonniere Can begin AROM immediately but watch for DIP ext lag. If lag > 10-15º splinting is recommendedq

Venous insufficiency symptoms

Cyanosis, abnormal capillary refill Manage by placing hand in slight elevation

Steindler procedure

Flexor pronator muscle tendon transfer to restore elbow flex after C5-C6 (upper trunk) brachial plexus injury. Flexor origin anchored to anterior humerus. Pronation initiates elbow flex

Abductor digiti minimi function

Increases span of grasp, assists with flexion of 5th MP

Opponens pollicis function

Inserts all along body of 1st metacarpal and rotates thumb medially Strongest opposer

Point of convergence during finger flexion

Scaphoid tubercle Most obvious during straight fist

Structures that form anatomical snuffbox

Scaphoid, EPL, APL, APB * Think scaphoid tenderness, thumb tendons (1st and 3rd DC)

Oblique retinacular ligament

Starts volar and proximal to PIP and merges with terminal tendon at dorsal DIP Controversial function • May link PIP/DIP motion, pulling DIP into ext with PIP ext • May be a check-rein against PIP HE • Others think it just provides lateral stability to PIP and centralizes extensor mechanism • Can contribute to DIP HE in boutonniere

Palmaris brevis innervation

Superficial branch of ulnar nerve

Flexor pollicis brevis innervation

Superficial head: Recurrent branch of median nerve (C8, T1) Deep head: Deep branch of ulnar nerve (C8, T1)

Quadrangular space borders

Superior: teres minor Inferior: teres major Lateral: humerus Medial: tricep

Quadrigia phenomenon

Flexion contracture of involved digit, decreased flexion force in adjacent digits. Can occur if FDP is advanced > 1 cm during repair resulting in limited proximal excursion of remaining FDP tendons

Supraspinatus insertion

Greater tubercle of humerus

Acute compartment syndrome requires

IMMEDIATE fasciotomy of all compartments involved! Possible causes: • Crush injury • Thermal or electrical burns • Snakebite • Fx Symptoms: disproportionate pain not relieved by rest, paresthesia, paralysis, lack of pulse, intrinsic minus in hand

Egawa's sign

TESTING: Ulnar nerve dysfunction POSITION: Patient puts hand on table in prone position and spreads fingers. Patient then attempts to move 3rd digit from side to side with finger slightly flexed. (+) TEST: Inability to abd/add middle finger, would still be able to flex

Cleland's ligament

Originates from flexor sheath and passes dorsally behind neurovascular bundle, inserting into skin dorsally. Prevents rotary movement of skin around fingers to facilitate grasp. Can remember ClelanD = D for dorsal

Abductor pollicis brevis function

Originates from trapezium and transverse carpal ligament, inserts on proximal phalanx and contributes to IP ext via extensor mechanism

Grayson's ligament

Originates from volar aspect of flexor sheath, runs volar to neurovascular bundle (in frontal plane), and inserts into skin. Prevents rotary movement of skin around fingers to facilitate grasp.

Muscles originating from common flexor origin

PT, FCR, PL, FCU No digital flexors!

Orthosis for swan neck

RIng orthosis in slight PIP flex

Artery that passes through anatomic snuff box

Radial artery

Periscapular ms contributing most to overhead reach

Upper trap, serratus anterior

Lumbrical plus phenomenon

When pt attempts to contract FDP but pulls lumbrical proximally, resulting in IP ext instead of flex Can occur when a flexor tendon graft is too long, directing force into the lumbrical

Palmaris brevis function

Wrinkles skin on ulnar side of palm

Brachialis insertion

Coronoid process of ulna

Length of protective phase following microvascular reconstruction

7-14 days to protect blood vessels • Be aware of arterial insufficiency signs including pallor, decreased temp, slow capillary refill

Martin-Gruber anastomosis

A communicating branch between median and ulnar nerve occurs high in forearm. Allows for median nerve to innervate intrinsics. In case of high (cubital tunnel) ulnar n. injury , pt would present with absent FDP to RF/SF but intact intrinsic function

Most critical pulleys required to maintain normal flexor tendon gliding

A2 and A4 Correspond to P1 and P2 respectively

Lacertus fibrosus

AKA bicipital aponeurosis • Tightens with pronation • Active elbow flex with pronation may cause it to compress median nerve

Strongest muscle for opposition

APB

1st dorsal compartment

APL, EPB

Strongest intrinsic muscle

Adductor pollicis

Adductor pollicis function

Adducts thumb into palm, gives power for grasp, inserts into extensor mechanism to assist IP to 0 ext

Volar interossei

Adducts thumb, index, ring, and small fingers

Riche-Cannieu anastomosis

Communication between deep ulnar branch to recurrent median thenar branch. Result is ulnar innervation of thenar muscles.

Pronator quadratus innervation

Anterior interosseous nerve

1st dorsal interosseous

Assists with thumb adduction, plays a significant role for writing/typing/pinch

Pectoralis major insertion

Bicipital groove of humerus

Major arterial supply to the forearm and hand

Brachial artery

Space of Poirier

Capitolunate joint Volar extrinsic ligaments in carpus form a V shape which leaves the capitolunate joint relatively unprotected. Allows lunate to dislocate during high velocity wrist injuries

Adductor pollicis innervation

Deep branch of ulnar nerve

Most efficient wrist extensor

ECRB

Primary muscle involved in lateral epicondylitis

ECRB

PIN innervated muscles

ECRB, ECU, EDC, EIP, EPL, EDM, APL, EPB

2nd dorsal compartment

ECRL, ECRB

6th dorsal compartment

ECU

4th dorsal compartment

EDC, EI

5th dorsal compartment

EDM

3rd dorsal compartment

EPL

Tendon that takes a 45º turn around Lister's tubercle

EPL Susceptible to rupture after DR fx or RA

Structure most commonly involved in trigger finger

FDS • You might think it's the A1 pulley because that's where it clicks/locks most often, but the biomechanical issue is swelling/thickening of FDS. Sometimes FDP too but less common. • Thickened FDS bunches up at distal pulley

Common hand dysfunction/deformity after hand replantation from transmetacarpal amputation

Intrinsic-minus posture Occurs when intrinsics are too injured to be repaired at surgery. Intrinsic tendons scar into canals in lengthened position. Can address by placing MPs in slight flex with anti-claw orthosis at 4 weeks until 12 weeks.

Subscapularis insetion

Lesser tubercle of humerus

How does MCP position affect the collateral ligaments?

Loose with MPs in extension, taut in flexion ** REMEMBER: be cautious about immobilizing with MPs in extension because collateral ligaments will contract

Only muscle that arises from and inserts into tendon

Lumbricals

Elbow's main stabilizer to valgus strain

MCL • Anterior bundle is main valgus stabilizer • Posterior bundle also helps out at 120º flex

Coracobrachialis insertion

Medial shaft of humerus

Medial and lateral borders of cubital fossa

Medial: pronator teres Lateral: brachioradialis

APB innervation

Median nerve

Structures contained in carpal tunnel

Median nerve, FPL, FDS x4, FDP x 4 10 structures in total.

TFCC composition

Meniscal homologue (disc) which includes ECU subsheath, ulnar collateral ligament, and volar and dorsal DRUJ ligaments

Snapping when flexing a swan neck digit is?

Movement of lateral bands

Landsmeer's ligament

ORL

Thumb pulley mostcritical to IP function

Oblique pulley Located at mid-portion of P1

Arterial insufficiency symptoms

Pallor, decreased temperature, increased pain, slow capillary refill, loss of pulse Manage by placing slightly below heart. Avoid excessive elevation

Artery and nerve passing through quadrangular space

Posterior circumflex artery Axillary nerve

EIP innervation

Posterior interosseous nerve

Brachioradialis innervation

Radial nerve

Opponens digiti minimi function

Rotates and draws 5th metacarpal anteriorly

Structures in Guyon's canal

Ulnar nerve and artery. Guyon's canal is immediately ulnar to carpal tunnel and may be site of ulnar n. entrapment. Some anatomic variants include aberrant ms crossing the canal.

Thumb pulley system

• A1 at MCP level • Oblique pulley across P1 • A2 at IP level

PIN compression sites

• Arcade of Froshe • Fibrous bands anterior to radial head • Radial recurrent vessels • Tendinous margin of ECRB • Deep surface of supinator muscle Radial tunnel!

Structures comprising radiocapitallar joint

• Capitulum • Radial head • Annular ligament • LCL • LUCL

3 veins that form an "M" in the volar forearm

• Cephalic vein (radial) • Median cubital vein • Basilic vein (ulnar)

Structures implicated in PIP flexion contractures

• Check-rein ligaments (most common) • Collateral ligaments • Volar plate

Marinacci anastomosis

• Communication from ulnar to median nerve in forearm. • Essentially reverse Martin-Gruber

Kienböck's disease

• Disruption of nutrients into the lunate, resulting in progressive necrosis and eventual collapse of lunate • Etiology is controversial but traditionally linked to negative ulnar variance (not proven!) • End stage (4) disease usually requires PRC

Scapholunate ligament composition

• Dorsal and volar ligamentous portions • Central membranous portion • Dorsal portion is strongest and vital to normal wrist motion

Factors contributing to swan neck deformity

• Dorsal migration of lateral bands • Mallet deformity can allow lateral band migration • Intrinsic tightness can pull on lateral bands, worsening deformity • Loss of FDS tendon can weaken PIP volar plate

Hook of hamate fx management

• Excision or ORIF • ORIF preferred in athletes as excision typically reduces grip strength by 15% • Restoring motion usually uncomplicated but athlete may require padding of racket/club handles

External rotation lag test

• Externally rotate humerus then abduct humerus to 20º while supporting wrist (+) if subject unable to maintain ER position and forearm lags into IR after releasing wrist • 5º-10º lag indicates possible supraspinatus tear • > 10º lag indicates possible tear of both supra/infraspinatus • Suprascapular nerve dysfunction may appear similar

Roof of the cubital tunnel

• FCU fascia • Arcuate ligament of Osborne Roof tightens with elbow flex.

Extrinsic flexor tightness test

• Hold digits in composite passive ext • Passively extend the wrist (+) if digits flex as wrist is extended. Note wrist position where flexor tightness is first detected

Extrinsic extensor tightness test

• Hold digits in composite passive flexion • Passively flex the wrist (+) if digits extend as wrist is flexed. Note wrist position where extensor tension is first detected

Passive structures that maintain GH stability

• Labrum • Superior and inferior GH ligaments • Joint capsule

Proximal compression sites of median nerve

• Ligament of Struthers just superior to med epi (don't confuse with ARCADE of Struthers which compresses ulnar nerve above cubital tunnel) • Bicipital aponeurosis aka lacertus fibrosis • FDS arch

Joint capsular tightness test

• Measure AROM and PROM (+) If measures are unchanged regardless of position of proximal and distal joints

Arcade of Froshe

• Most common site for PIN compression • Semicircular structure that arises from tip and medial aspect of lat epi

Drop sign test

• Place humerus in full ER and 90º scaption (+) if lag into IR when releasing wrist, indicating full thickness supraspinatus tear • Suprascapular nerve dysfunction may appear similar

Lumbrical function

• Primarily a sensory organ that allows hand to balance forces between flexor and extensor systems • Rich in muscle spindles, especially the radial lumbricals • Actually quite weak contributors to the "lumbrical grasp"

Attachment sites of transverse carpal ligament

• Scaphoid tuberosity • Crest of trapezium • Pisiform • Hook of hamate

Vascular structure of hand

• Superficial palmar arch (primarily from ulnar a.) • Deep palmar arch (primarily from radial a.) • Common palmar arteries (come from superficial arch) Both radial and ulnar nerve do have at least some contribution to non-primary arch

Hook of hamate fx symptoms

• TTP just distal to pisiform • Pain with wrist ext, UD, and flexion of RF/SF • Common in racket/baseball/golf athletes, workers who strike palm frequently (e.g., to close lids)

Spiral ORL reconstruction

• To address mallet or swan neck deformities • Take a tendon graft, anchoring to dorsal P3 • Spiral around volar aspect of PIP and anchor to P1 Developed by Littler et al.

Cozen's test

• To test lat epi • Resist wrist ext with elbow in flex, then in ext (+) with sharp pain reproduction at lat epi