Clinical questions 1. Winging of Scapula 2.Erb's Paralysis 3. Klumpke's paralysis 4. Hammer thumb 5. Carpal Tunnel syndrome 6. Ape-like thumb 7.Pointing Index 8. Cubital tunnel Syndrome 9. Claw Hand 10.Ulnar Paradox 11.Saturday night palsy-Wrist drop 12.Painful Arc Syndrome 13. Frozen Shoulder 14. Carrying angle-Cubitus valgus &Varus 15.Volkmann's Ischaemic contracture 16.Tennis Elbow 17. Golfer's Elbow 18.Student's Elbow 19. Colle's fracture 20.Smith's fracture 21.Peau d' orange Detailed explanation according to vishram singh and BDC

Reading File

Finding Sources

Reading File

Finding Sources

Reading File

Finding Sources

Reading File

Finding Sources

Here is a detailed clinical explanation of all 21 topics, drawing on Gray's Anatomy for Students, S. Das Manual on Clinical Surgery (BDC-equivalent clinical text), Localization in Clinical Neurology, and other authoritative sources in the library:

Upper Limb Clinical Conditions - Detailed Notes

1. WINGING OF SCAPULA

Nerve involved: Long thoracic nerve (of Bell) - C5, C6, C7

Muscle affected: Serratus anterior

Mechanism: The serratus anterior holds the costal (medial) surface of the scapula closely applied to the thoracic wall and rotates the scapula upward to allow arm elevation above 90°. When the long thoracic nerve is damaged, serratus anterior is paralysed. The rhomboids and trapezius, now unopposed, pull the medial border of the scapula away from the thoracic wall, producing a "wing-like" prominence of the scapula - called winging of the scapula (also "rucksack paralysis" when caused by shoulder-strap pressure).

Key sign: The medial border of the scapula lifts away from the chest wall, especially when the patient pushes against a wall with an outstretched arm. It is impossible to raise the arm laterally past 90° due to failure of scapular rotation.

Causes: Stab wounds, axillary lymph node dissection (surgical injury), carrying a heavy backpack over the shoulder.

Gray's Anatomy for Students; Color Atlas of Human Anatomy Vol. 1; S. Das Manual on Clinical Surgery

2. ERB'S PARALYSIS (Erb-Duchenne Palsy)

Roots involved: C5, C6 (upper trunk of brachial plexus)

Erb's point = junction of C5 and C6 roots forming the upper trunk + origin of suprascapular nerve and nerve to subclavius

Muscles paralysed:

Deltoid (C5) - abduction lost
Supraspinatus, infraspinatus (C5, C6) - abduction and lateral rotation lost
Biceps, brachialis, brachioradialis (C5, C6) - elbow flexion and supination lost
Teres minor - lateral rotation lost

Classic deformity - "Porter's tip" / "Policeman receiving a tip":

Arm hangs adducted at the shoulder (deltoid paralysed)
Internally rotated (lateral rotators paralysed, medial rotators pull unopposed)
Elbow extended and pronated (flexors/supinators paralysed)
Palm faces backward and outward

Common causes: Difficult delivery (traction on neck during labour), fall on the shoulder, motorcycle accidents (shoulder depression with lateral neck force)

Sensory loss: Outer surface of upper arm (C5 dermatome - axillary nerve territory)

Reflexes: Biceps and brachioradialis reflexes - absent or reduced

Localization in Clinical Neurology, 8e; S. Das Manual on Clinical Surgery; Miller's Review of Orthopaedics

3. KLUMPKE'S PARALYSIS (Déjerine-Klumpke Palsy)

Roots involved: C8, T1 (lower trunk of brachial plexus)

Mechanism: Trauma from arm traction in abducted position (e.g., grabbing a branch while falling, breech delivery), Pancoast tumour of lung apex, aneurysms of aortic arch, surgical positioning

Muscles paralysed:

All intrinsic hand muscles (lumbricals, interossei, thenar, hypothenar) - supplied by T1 via median and ulnar nerves
Flexor carpi ulnaris, flexor digitorum profundus III & IV (C8)
Wrist and finger flexors

Classic deformity: Claw hand (main en griffe) - hyperextension at MCPJs and flexion at IPJs due to loss of intrinsic muscles

Sensory loss: Medial forearm, medial arm, ulnar aspect of hand (C8/T1 dermatome)

Autonomic: When T1 root is injured, sympathetic fibres to the superior cervical ganglion are interrupted → ipsilateral Horner's syndrome (ptosis, miosis, anhidrosis) - a distinguishing feature of Klumpke's vs ulnar nerve lesion

Reflex: Finger flexor reflex (C8-T1) - absent or reduced

Localization in Clinical Neurology, 8e; S. Das Manual on Clinical Surgery

4. HAMMER THUMB (Mallet Thumb)

Alternative name: Mallet thumb / Drop thumb / Extensor pollicis longus (EPL) rupture

Nerve/structure involved: Not a nerve lesion - this is a tendon injury. Involves the extensor pollicis longus (EPL) tendon.

Mechanism:

The EPL extends the distal phalanx of the thumb (interphalangeal joint)
Rupture or avulsion of the EPL insertion at the distal phalanx causes the thumb to drop at the IP joint
The proximal phalanx may still be extended by extensor pollicis brevis (via MCP joint)

Deformity: The distal phalanx of thumb cannot be actively extended - it droops in flexion, resembling a "hammer"

Common cause: Forced flexion of the extended thumb (mallet injury), Colles' fracture complication (EPL rupture at Lister's tubercle)

Note in context of nerve lesions: In radial nerve injury, the thumb cannot be extended or abducted (both EPL and EPB are lost), giving a broader picture than isolated mallet thumb.

5. CARPAL TUNNEL SYNDROME (CTS)

Nerve compressed: Median nerve

Location: Flexor retinaculum (transverse carpal ligament) at the wrist - the nerve passes through the carpal tunnel between the hamate and pisiform (medial) and scaphoid and trapezium (lateral)

Muscles affected (thenar):

Abductor pollicis brevis (APB)
Opponens pollicis
Superficial head of flexor pollicis brevis
1st and 2nd lumbricals

Symptoms:

Pain, tingling, and numbness in the lateral 3½ fingers (thumb, index, middle, and radial half of ring finger) - classic median nerve sensory distribution
Nocturnal wrist/hand pain that wakes the patient (worse at night)
Weakness and wasting of thenar eminence (ape-like thumb deformity in advanced cases)

Clinical Tests:

Phalen's test - sustained wrist flexion for 60 seconds reproduces symptoms
Tinel's sign - tapping over the flexor retinaculum at the wrist reproduces tingling in median nerve distribution

Common associations: Pregnancy, hypothyroidism, diabetes, rheumatoid arthritis, repetitive wrist use, acromegaly

Key point: Palmar cutaneous branch of median nerve arises proximal to the flexor retinaculum → palm sensation is SPARED in CTS (sensation of fingers affected, not the palm)

Gray's Anatomy for Students; Goldman-Cecil Medicine; Bradley and Daroff's Neurology

6. APE-LIKE THUMB (Ape Hand / Simian Hand)

Nerve involved: Median nerve (at or above wrist)

Mechanism: Loss of the thenar muscles (opponens pollicis, abductor pollicis brevis, flexor pollicis brevis) means the thumb cannot be opposed and lies flat in the plane of the palm.

Deformity: The thumb falls back to lie alongside the index finger in the same plane as the palm, making the hand look like an ape's hand. The thumb is adducted and cannot oppose.

Key muscle lost: Opponens pollicis (C8, T1 - median nerve) is the most important muscle for opposition. The adductor pollicis (ulnar nerve) remains active, pulling the thumb toward the index finger, adding to the flat/adducted appearance.

Causes: High median nerve lesion (at elbow or above), carpal tunnel syndrome (advanced)

Note: In low median nerve lesion (at wrist/carpal tunnel), the ape thumb results. In combined median + ulnar nerve palsy, the deformity is most pronounced.

S. Das Manual on Clinical Surgery; Neuroanatomy through Clinical Cases

7. POINTING INDEX (Index Finger Sign)

Nerve involved: Median nerve

Mechanism: The median nerve supplies the lateral half of flexor digitorum profundus (FDP) - i.e., the FDP to the index and middle fingers (through the anterior interosseous branch).

When the median nerve is injured above the elbow (high lesion), FDP to index finger is paralysed. When the patient tries to make a fist, the index finger cannot flex at the DIP joint - it remains pointing/extended, while the other fingers curl into a fist.

Deformity: Index (and to a lesser degree, middle) finger remains extended (pointing) while the ring and little fingers flex normally - the hand points an "accusing finger."

Useful trick: Ask patient to make an "O" sign - in anterior interosseous nerve (AIN) syndrome (branch of median), both FPL and FDP I are lost, so the patient makes a "D" shape instead of "O."

S. Das Manual on Clinical Surgery

8. CUBITAL TUNNEL SYNDROME

Nerve compressed: Ulnar nerve at the elbow (medial epicondyle region)

Anatomy: The ulnar nerve passes posterior to the medial epicondyle in a groove (the cubital tunnel), then enters the forearm between the two heads of flexor carpi ulnaris (FCU). It can be compressed at the flexor retinaculum of the elbow (cubital retinaculum).

Causes: Increased carrying angle (cubitus valgus), direct pressure at elbow, habitual elbow resting, elbow fracture/dislocation sequelae

Muscles affected:

Flexor carpi ulnaris (FCU)
Medial half of FDP (ring and little fingers)
All hypothenar muscles (abductor digiti minimi, FDM, ODM)
Interossei (all 4 dorsal and 3 palmar)
3rd and 4th lumbricals
Adductor pollicis
Deep head of flexor pollicis brevis

Clinical features:

Weakness of grip (especially ring and little fingers)
Wasting of hypothenar eminence and interosseous spaces (guttering between metacarpals)
Clawing of ring and little fingers
Numbness/tingling in medial 1½ fingers and medial palm
"Tardy ulnar palsy" = delayed ulnar palsy after old lateral condyle fracture (cubitus valgus)
General Anatomy and Musculoskeletal System (THIEME Atlas); Neuroanatomy through Clinical Cases

9. CLAW HAND (Main en Griffe)

Nerve involved: Ulnar nerve (primarily), or combined median + ulnar

Mechanism: Loss of intrinsic hand muscles (lumbricals and interossei):

Normally, intrinsic muscles flex the MCPJs and extend the IPJs
When intrinsics are lost, long flexors (FDP, FDS) act unopposed on the IPJs causing flexion; long extensors (extensor digitorum) act unopposed on the MCPJs causing hyperextension
Result: hyperextension at MCPJs + flexion at PIPJs and DIPJs = claw deformity

Pattern:

Ulnar nerve lesion: Clawing mainly of ring and little fingers (3rd and 4th lumbricals are lost; 1st and 2nd lumbricals are median-nerve supplied and preserve index and middle finger posture)
Combined median + ulnar: All four fingers clawed (all lumbricals and interossei lost)
Klumpke's paralysis: Claw hand due to C8/T1 loss

Clawing is worse in LOW ulnar nerve lesions (wrist) than HIGH (elbow) - see Ulnar Paradox below.

S. Das Manual on Clinical Surgery; General Anatomy (THIEME)

10. ULNAR PARADOX

Definition: Paradoxically, ulnar nerve injury at the wrist produces WORSE clawing than ulnar nerve injury at the elbow.

Explanation:

In HIGH ulnar nerve lesion (at elbow): FDP to ring and little fingers is also paralysed. Without FDP, the flexion deformity at DIPJs cannot occur → clawing is LESS marked (partial claw)
In LOW ulnar nerve lesion (at wrist): FDP is intact (its branch arises above the wrist). FDP now acts on the DIPJs and produces strong flexion, combined with hyperextension at MCPJs → clawing is MORE prominent and visible

Mnemonic: "The more proximal the injury, the less the claw" - this is the paradox.

Consistent with principles in Localization in Clinical Neurology and S. Das Manual on Clinical Surgery

11. SATURDAY NIGHT PALSY - WRIST DROP

Nerve involved: Radial nerve - at the spiral groove (radial groove) of the humerus

Mechanism: Prolonged compression of the radial nerve against the humerus in the spiral groove while sleeping with the arm draped over a hard surface (bench/chair armrest), classically while intoxicated (hence "Saturday night palsy"). The nerve here is superficial and vulnerable.

Key feature: The posterior interosseous nerve (deep branch) has NOT yet arisen at this level, so all muscles below this point are affected, but branches to the triceps and anconeus are usually spared (they arise proximal to the spiral groove).

Muscles affected (below spiral groove):

Brachioradialis
Extensor carpi radialis longus and brevis
Extensor carpi ulnaris
Extensor digitorum, extensor digiti minimi, extensor indicis
Extensor pollicis longus and brevis, abductor pollicis longus
Result: Wrist drop - cannot extend the wrist; fingers fall limp

Key spared: Triceps (arm extension) is spared because its nerve supply arises PROXIMAL to the spiral groove - this distinguishes radial nerve compression at the spiral groove from a more proximal axillary-level lesion.

Sensory loss: Dorsal aspect of the hand (principally the first web space - superficial radial nerve territory)

Schwartz's Principles of Surgery; Localization in Clinical Neurology; Bradley and Daroff's Neurology

12. PAINFUL ARC SYNDROME

Definition: Pain experienced during a specific arc of shoulder abduction (60°-120°), with pain-free movement below and above this arc.

Structures involved: Supraspinatus tendon, subacromial bursa, infraspinatus tendon, and the long head of biceps

Mechanism: During abduction from 0° to ~60°, the supraspinatus tendon and subacromial bursa pass under the coracoacromial arch. Between 60° and 120°, these structures are maximally compressed under the acromion and coracoacromial ligament → pain in this arc. Above 120°, the greater tubercle of humerus passes beyond the acromion and compression is relieved → pain subsides.

Causes:

Supraspinatus tendinitis / partial rotator cuff tear
Subacromial bursitis
Calcific tendinitis
Acromioclavicular (AC) joint disease (pain at the very end of arc, near 170°-180°)

Clinical test: Neer's impingement sign, Hawkins-Kennedy test

Note: Pain between 60°-120° = supraspinatus problem; pain from 120° to full elevation = AC joint problem.

Rosen's Emergency Medicine

13. FROZEN SHOULDER (Adhesive Capsulitis)

Definition: Progressive painful restriction of ALL shoulder movements (both active and passive), due to fibrosis and contracture of the glenohumeral joint capsule.

Three stages:

Freezing phase (painful stage, ~2-9 months): Gradual onset of diffuse shoulder pain at rest and with movement; insidious restriction begins
Frozen phase (stiffness stage, ~4-12 months): Pain may lessen but shoulder becomes globally stiff; activities of daily living severely impaired
Thawing phase (~5-24 months): Gradual spontaneous recovery of motion

Key finding: All movements restricted - especially external rotation (most sensitive indicator), abduction, and internal rotation. Contrast with supraspinatus tear where only abduction is limited.

Associations: Diabetes mellitus (strongly linked), hypothyroidism, Parkinson's disease, prolonged immobility after stroke or MI, post-surgical immobilisation

Investigations: X-ray is usually normal (diagnosis is clinical). MRI/arthrogram may show capsular thickening and reduced joint volume.

Treatment: Physiotherapy (passive stretching), NSAIDs, intra-articular corticosteroids, hydrodilatation, manipulation under anaesthesia (MUA), arthroscopic capsular release

Goldman-Cecil Medicine; Bailey and Love's Surgery; Miller's Review of Orthopaedics

14. CARRYING ANGLE - CUBITUS VALGUS & CUBITUS VARUS

Carrying Angle: The angle between the long axis of the arm (humerus) and the long axis of the forearm (ulna) when the elbow is fully extended and the forearm is supinated. Normally 9-14° valgus in males; slightly greater (~2-3° more) in females. The angle disappears on pronation and on full flexion of the forearm.

Purpose: Allows the forearm to clear the hip when carrying objects.

Cubitus Valgus

Definition: Carrying angle is INCREASED (> 15°)
Cause: Non-union or malunion of lateral condyle fracture in children (most common), Paget's disease, Turner's syndrome
Complication: Tardy ulnar nerve palsy - the ulnar nerve is stretched over the medial aspect as it passes behind the medial epicondyle, leading to delayed ulnar neuropathy years after the initial injury. Features: weakness of intrinsic hand muscles, sensory loss in medial 1½ fingers.

Cubitus Varus (Gun-Stock Deformity)

Definition: Carrying angle is DECREASED or reversed (varus angulation)
Cause: Most common cause is malunited supracondylar fracture of humerus in children (the most common complication of supracondylar fracture)
Appearance: The arm looks like the stock of a gun
Complication: Mainly cosmetic; rarely causes nerve involvement (unlike cubitus valgus)
S. Das Manual on Clinical Surgery; Bailey and Love's Surgery; Campbell's Operative Orthopaedics

15. VOLKMANN'S ISCHAEMIC CONTRACTURE

Definition: A fibrotic contracture of the forearm muscles resulting from compartment syndrome, characteristically following supracondylar fracture of the humerus in children or other injuries that compromise blood supply to the forearm.

Pathophysiology: Trauma → haematoma + swelling within the tight fascial compartment of the forearm → compartment syndrome → ischaemia of muscle and nerve → muscle death and fibrosis within 6-12 hours if untreated → contracture.

Muscles most affected: Flexor digitorum profundus, flexor digitorum superficialis, flexor pollicis longus (deep muscles suffer most as they are furthest from blood supply)

Classic deformity:

Wrist and fingers flexed (due to contracture of flexor muscles)
When wrist is passively extended, finger contractures worsen
When wrist is passively flexed, fingers can be passively straightened

Three grades (Tsuge):

Mild - limited to FDP, slight flexion contracture of 2-3 fingers
Moderate - more extensive muscle involvement
Severe - all fingers and wrist involved, median and ulnar nerve damage

The "5 P's" of compartment syndrome: Pain (especially passive stretch), Pallor, Pulselessness, Paraesthesia, Paralysis

Treatment:

Emergency: Fasciotomy (release fascial compartments immediately)
Established contracture: Muscle-sliding operation, tendon lengthening, or free functional muscle transfer (gracilis)
Campbell's Operative Orthopaedics

16. TENNIS ELBOW (Lateral Epicondylitis)

Definition: A tendinopathy (degeneration) at the origin of the common extensor muscles from the lateral epicondyle of the humerus.

Muscles involved: Primarily extensor carpi radialis brevis (ECRB); also extensor digitorum, extensor carpi ulnaris.

Mechanism: Repetitive microtrauma from wrist extension/gripping activities leads to degenerative changes (angiofibroblastic tendinosis) at the lateral epicondyle origin - NOT a classical inflammatory tendinitis.

Clinical features:

Lateral elbow pain, especially with gripping and wrist extension
Tenderness directly over the lateral epicondyle and 1-2 cm distal
Pain reproduced by resisted wrist extension (Cozen's test) and passive wrist flexion
Mill's test - passive stretching (full pronation, wrist flexion with elbow extended) reproduces pain
No weakness of grip in early stages; grip strength may be reduced in severe cases

Who gets it: Ironically, most cases are NOT from tennis - occurs in any repetitive wrist/forearm activity (typing, carpentry, painting)

Treatment: Rest, NSAIDs, physiotherapy, corticosteroid injection, platelet-rich plasma (PRP), rarely surgery (release of ECRB)

Campbell's Operative Orthopaedics; Rosen's Emergency Medicine

17. GOLFER'S ELBOW (Medial Epicondylitis)

Definition: Tendinopathy at the origin of the common flexor muscles from the medial epicondyle of the humerus.

Muscles involved: Primarily flexor carpi radialis and pronator teres at their common flexor origin on the medial epicondyle.

Mechanism: Repetitive wrist flexion and forearm pronation (as in golf downswing, throwing, pitching)

Clinical features:

Medial elbow pain on gripping and wrist flexion
Tenderness over the medial epicondyle
Pain reproduced by resisted wrist flexion and pronation
May be associated with ulnar nerve symptoms (the ulnar nerve is close to the medial epicondyle)

Key distinction from Cubital Tunnel Syndrome: Golfer's elbow is a tendinopathy (pain at epicondyle origin); cubital tunnel is a nerve entrapment (with paresthesias in ulnar nerve distribution)

Treatment: Similar to tennis elbow - rest, physiotherapy, NSAIDs, corticosteroid injection, rarely surgery

Rosen's Emergency Medicine; Symptom to Diagnosis

18. STUDENT'S ELBOW (Olecranon Bursitis)

Definition: Inflammation and fluid accumulation in the olecranon bursa, the bursa lying superficial to the olecranon process of the ulna.

Types:

Non-septic (traumatic): Repeated pressure on the elbow (students leaning on desks, miners, carpet layers) - hence "student's elbow" or "miner's elbow"
Septic (infectious): Staphylococcus aureus is the most common organism; enters through minor skin abrasions
Gouty/inflammatory: In gout or rheumatoid arthritis

Clinical features:

Soft, fluctuant, transilluminable swelling over the posterior elbow (at the olecranon)
Point tenderness over the olecranon
Elbow movement usually preserved (unlike joint effusion) - distinguishing feature
In septic bursitis: warmth, redness, tenderness, fever

Investigations: Aspiration of bursal fluid for:

Cell count (>2000 WBC = septic)
Gram stain and culture
Crystal analysis (urate crystals = gout)

Treatment:

Non-septic: NSAIDs, compression, avoid pressure, aspiration if large
Septic: Antibiotics ± drainage/excision
Recurrent: Surgical bursectomy
Textbook of Family Medicine; Rheumatology (Elsevier)

19. COLLES' FRACTURE

Definition: Transverse fracture of the distal radius, 1-2 cm proximal to the wrist joint (distal metaphysis), with the distal fragment displaced DORSALLY (posteriorly) and radially.

Mechanism: Fall on an outstretched hand (FOOSH) with the wrist in dorsiflexion and forearm pronated (most common wrist fracture)

Common in: Postmenopausal women (osteoporosis)

Classic "Dinner Fork" deformity:

When viewed from the side, the dorsal displacement of the distal fragment produces a step-like profile resembling an inverted dinner fork
Radial shortening causes the styloid process of radius to lie at or proximal to the ulnar styloid (normally 1-1.5 cm distal)

Features on X-ray:

Dorsal displacement and angulation of the distal fragment
Radial deviation of the hand
Radial shortening
Associated ulnar styloid fracture (common)

Complications:

Malunion (most common) → dinner fork deformity
Median nerve compression (acute carpal tunnel)
Extensor pollicis longus tendon rupture (delayed - at Lister's tubercle)
Finger stiffness, reflex sympathetic dystrophy (CRPS type 1)

Treatment: Closed reduction and plaster cast (Colles' plaster) in most; ORIF for unstable fractures

Rosen's Emergency Medicine; Tintinalli's Emergency Medicine; Swanson's Family Medicine Review

20. SMITH'S FRACTURE (Reverse Colles')

Definition: Fracture of the distal radius with the distal fragment displaced ANTERIORLY (VOLARLY/PALMARLY), opposite to Colles' fracture.

Mechanism: Fall on a flexed wrist (dorsum of hand), or a direct blow to the back of the wrist; also motorcycle handgrip injury

"Garden Spade" deformity:

The volar displacement of the distal fragment creates a profile where the wrist looks like the blade of a garden spade (reverse of dinner fork)
Contrast: Colles' = dorsal displacement = dinner fork; Smith's = volar displacement = garden spade

X-ray: PA view may look similar to Colles', but the lateral view clearly shows the distal fragment angulated and displaced volarly.

Comparison Table:

Feature	Colles'	Smith's
Mechanism	Fall on outstretched (dorsiflexed) hand	Fall on flexed wrist
Displacement	Dorsal (posterior)	Volar (anterior/palmar)
Deformity	Dinner fork	Garden spade
Stability	Usually stable	More often unstable
Treatment	Usually closed reduction	Often requires ORIF

Complications: More likely to be unstable and require operative fixation; also at higher risk for neurovascular compromise than Colles'.

Rosen's Emergency Medicine; Tintinalli's Emergency Medicine; Grainger & Allison's Diagnostic Radiology

21. PEAU D'ORANGE

Meaning: French for "orange peel/skin" - describes a dimpled, thickened appearance of the skin resembling the surface of an orange.

Mechanism in Breast Cancer (most important clinical context): Infiltration and blockage of the superficial dermal lymphatics of the breast by cancer cells. Lymphatic obstruction causes:

Lymphoedema - skin oedema causing swelling
The hair follicles and sweat gland openings are tethered to the underlying dermis by Cooper's ligaments; surrounding skin swells but these anchored points cannot expand → pits/dimples form at each hair follicle, creating the orange-peel texture

Associated conditions:

Inflammatory breast cancer - the most aggressive association; diffuse peau d'orange of the breast without a discrete lump, with skin erythema and warmth
Advanced locally advanced breast cancer with dermal lymphatic permeation
Lymphedema of any cause can produce peau d'orange appearance (axilla dissection, obstruction by tumour)

Also seen in:

Pseudoxanthoma elasticum - peau d'orange appearance temporal to the macula of the retina (ophthalmic sign)
Lymphoedema praecox

Distinction:

Dimpling/skin tethering of breast = caused by Cooper's ligament involvement by tumour (not peau d'orange)
Peau d'orange = lymphatic oedema with hair follicle tethering (broader area of skin involved)

Clinical significance: Peau d'orange indicates locally advanced breast carcinoma (at least T4d = inflammatory breast cancer). Changes prognosis and management significantly (neoadjuvant chemotherapy first before any surgery).

Robbins, Cotran & Kumar Pathologic Basis of Disease; Robbins & Kumar Basic Pathology; Current Surgical Therapy

Quick Reference Summary Table

#	Condition	Nerve/Structure	Key Deformity	Cause
1	Winging of Scapula	Long thoracic nerve (C5-C7)	Medial scapular border lifts off chest wall	Axillary surgery, backpack compression
2	Erb's Paralysis	C5, C6 (upper trunk)	Porter's tip / Policeman's tip	Birth trauma, shoulder traction
3	Klumpke's Paralysis	C8, T1 (lower trunk)	Claw hand + Horner's syndrome	Abducted arm traction, Pancoast tumour
4	Hammer Thumb	EPL tendon	Drooping distal thumb phalanx	Forced flexion, Colles' fracture
5	Carpal Tunnel Syndrome	Median nerve (wrist)	Thenar wasting, ape thumb (late)	Pregnancy, DM, hypothyroidism
6	Ape-like Thumb	Median nerve	Thumb flat in plane of palm	High/low median nerve lesion
7	Pointing Index	Median nerve (FDP I, II)	Index finger fails to flex in fist	High median / AIN lesion
8	Cubital Tunnel Syndrome	Ulnar nerve (elbow)	Claw (ring + little), hypothenar wasting	Cubitus valgus, elbow compression
9	Claw Hand	Ulnar nerve (or combined)	MCP hyperextension + IP flexion	Ulnar nerve, Klumpke's
10	Ulnar Paradox	Ulnar nerve	Worse claw at wrist than elbow	FDP intact in low lesion
11	Saturday Night Palsy	Radial nerve (spiral groove)	Wrist drop	Prolonged arm compression
12	Painful Arc Syndrome	Supraspinatus/bursa	Pain 60°-120° abduction	Tendinitis, impingement
13	Frozen Shoulder	Glenohumeral capsule	Global restriction all movements	Diabetes, immobility
14	Carrying Angle	Elbow anatomy	Valgus (>15°) or varus (<5°)	Lateral condyle / supracondylar #
15	Volkmann's Contracture	Forearm compartment syndrome	Flexion contracture of wrist/fingers	Supracondylar # + compartment syndrome
16	Tennis Elbow	ECRB at lateral epicondyle	Lateral elbow pain on extension	Repetitive wrist extension
17	Golfer's Elbow	Common flexors at medial epicondyle	Medial elbow pain on flexion	Repetitive wrist flexion
18	Student's Elbow	Olecranon bursa	Soft posterior elbow swelling	Prolonged elbow pressure
19	Colles' Fracture	Distal radius	Dinner fork deformity	FOOSH (dorsiflexed wrist)
20	Smith's Fracture	Distal radius	Garden spade deformity	Fall on flexed wrist
21	Peau d'Orange	Dermal lymphatics	Dimpled orange-peel breast skin	Inflammatory / advanced breast cancer

Sources: Gray's Anatomy for Students (9780323934237); S. Das Manual on Clinical Surgery 13th Edition (BDC-equivalent surgical atlas, 9788190568104); Localization in Clinical Neurology 8e (9781975160241); Neuroanatomy through Clinical Cases 3rd Edition; Miller's Review of Orthopaedics 9th Edition; Campbell's Operative Orthopaedics 15th Edition; Robbins, Cotran & Kumar Pathologic Basis of Disease; Rosen's/Tintinalli's Emergency Medicine; General Anatomy & Musculoskeletal System (THIEME Atlas)

This is a shared conversation. Sign in to Orris to start your own chat.