Hands
2. Definition
Page 2 – Definition
| Definition |
|---|
| • The hand is the most distal and functionally expressive part of the upper limb. • It integrates 27 bones, multiple joints, intrinsic and extrinsic muscles, and complex neural control. • Enables essential human functions such as grasp, manipulation, tactile exploration, and non-verbal expression. • The hand is a symbol of intelligence and identity, central to art, science, and civilization. |
| Component | Details |
|---|---|
| Structure | Bones, muscles, joints, ligaments, nerves, vessels, and fascia form a tightly integrated system. |
| Function | Precision grip, power grip, tactile discrimination, fine motor tasks, gesturing, and communication. |
| Common Diseases | Carpal tunnel syndrome, arthritis, scaphoid fractures, trigger finger. |
| Diagnosis | Physical exam, X-ray, CT, MRI, ultrasound, EMG/NCS. |
| Treatment | Splinting, medications, injections, surgery, physical/occupational therapy. |
3. Anatomy
Page 3 – Applied Anatomy and Diagnostic Approach
| Category | Details |
|---|---|
| Units (U) | Bone Units: • Scaphoid • Lunate • Triquetrum • Pisiform • Trapezium • Trapezoid • Capitate • Hamate • First to Fifth Metacarpals • Proximal Phalanges (5) • Middle Phalanges (4) • Distal Phalanges (5)Muscle Units: • Thenar: Abductor pollicis brevis, Opponens pollicis, Flexor pollicis brevis • Hypothenar: Abductor digiti minimi, Flexor digiti minimi brevis, Opponens digiti minimi • Lumbricals (4) • Dorsal interossei (4) • Palmar interossei (3) • Extrinsic inserting muscles: Flexor digitorum superficialis, Flexor digitorum profundus, Extensor digitorum, Extensor indicis, Extensor digiti minimi, Extensor pollicis longus/brevis, Abductor pollicis longus |
| Size | Carpal bones ~1–2 cm; metacarpals and phalanges progressively smaller toward the fingertip |
| Shape | Irregular carpal bones; long cylindrical metacarpals and phalanges; arched palm for grip |
| Position | Terminal structure of the upper limb, distal to the wrist; structured in palm and fingers |
| Character | Highly mobile, dexterous, and richly innervated; integrates strength and precision |
| Time | Ossification completes by adolescence; prone to degenerative changes and trauma with age |
| Connections | |
| – Arterial supply | Superficial palmar arch (ulnar), Deep palmar arch (radial), Proper digital arteries |
| – Venous drainage | Dorsal venous arch, Cephalic and Basilic veins |
| – Lymphatic drainage | Epitrochlear and Axillary lymph nodes |
| – Nerve supply | Median (thenar, lateral palm), Ulnar (hypothenar, medial hand), Radial (dorsal sensory) |
| – Ducts | Not applicable |
Imaging Modalities
| Modality | Primary Use | When/Why Used |
|---|---|---|
| X-ray | Bone alignment, fracture, arthritis | First-line in trauma or joint complaints |
| CT | Detailed bony anatomy, subtle fractures | When X-ray is equivocal or surgical planning |
| MRI | Soft tissue, ligaments, tendons, nerves | Carpal tunnel, tendon injury, mass |
| Ultrasound | Dynamic tendon motion, fluid | Trigger finger, tenosynovitis, ganglion |
| EMG/NCS | Nerve conduction function | Carpal tunnel, ulnar neuropathy |
Laboratory Tests
| Test | Purpose | When/Why Used |
|---|---|---|
| ESR, CRP | Detect inflammation or infection | Suspected arthritis or septic joint |
| RF, ANA | Screen for autoimmune disease | Suspected RA or lupus |
| CBC | Evaluate systemic signs | Fever, swelling, red hand, systemic illness |
Other Diagnostic Tools
| Tool | Use | Indication |
|---|---|---|
| Phalen’s and Tinel’s Tests | Screen for median nerve compression | Suspected carpal tunnel |
| Allen’s Test | Evaluate radial/ulnar arterial flow | Pre-arterial line placement |
| Arthrocentesis | Aspiration and analysis of joint fluid | Gout, septic arthritis |
4. Disease and Diagnosis
Page 4 – Clinical Diagnosis
| Category | Examples |
|---|---|
| Inflammatory/Immune | Rheumatoid arthritis, psoriatic arthritis |
| Infection | Paronychia, felon, septic arthritis |
| Neoplasm – Benign | Ganglion cyst, giant cell tumor of tendon sheath |
| Neoplasm – Malignant (Primary) | Synovial sarcoma |
| Neoplasm – Malignant (Metastatic) | Rare (e.g., breast, lung) |
| Mechanical | Trigger finger, De Quervain’s |
| Trauma | Scaphoid or phalangeal fracture, dislocation |
| Metabolic | Gout, pseudogout |
| Circulatory | Raynaud’s, ischemia |
| Inherited | Syndactyly, polydactyly |
| Infiltrative | Amyloidosis (rare) |
| Idiopathic | Dupuytren’s contracture |
| Iatrogenic | Post-op nerve entrapment |
| Functional | Repetitive strain injury |
| Psychiatric | Factitious injury |
Clinical Signs and Symptoms
| Symptom | Interpretation |
|---|---|
| Numbness in fingers | Nerve compression (median or ulnar) |
| Locking of finger | Trigger finger |
| Swelling and redness | Infection, inflammation |
| Weak grip | Nerve or tendon injury |
| Deformity | RA, dislocation, fracture |
5. History and Culture
Page 5 – History, Culture, and Art (Fully Expanded)
1. History of Anatomy
| Topic | Content |
|---|---|
| Early anatomy | Leonardo da Vinci’s hand studies, Vesalius’ systematized dissections, and Galen’s influence shaped modern understanding. |
2. History of Physiology
| Topic | Content |
|---|---|
| Cortical mapping | The hand’s motor and sensory control occupies vast regions of the brain — enabling fine, voluntary movement and tactile acuity. |
3. History of Diagnosis
| Topic | Content |
|---|---|
| Clinical signs | Use of bedside maneuvers like Tinel’s, Froment’s, and Allen’s tests remain central to clinical neurology and vascular assessment. |
4. History of Imaging
| Topic | Content |
|---|---|
| Radiology origins | The first medical X-ray was of a hand (Röntgen’s wife’s) — launching diagnostic imaging as a field. |
5. History of Laboratory Testing
| Topic | Content |
|---|---|
| Synovial and autoimmune testing | Synovial fluid analysis (gout, septic joint), ANA, RF, and anti-CCP transformed autoimmune hand disease detection. |
6. History of Therapies
| Topic | Content |
|---|---|
| Surgical evolution | Dr. Sterling Bunnell developed tendon repair and replantation during WWII, founding the specialty of hand surgery. |
7. Cultural Meaning
| Culture/Context | Meaning |
|---|---|
| Religious and symbolic | The hand is a symbol of blessing (Christian), protection (Hamsa), and power (mudras) in many cultures. |
8. Artistic Representations
| Example | Meaning |
|---|---|
| Creation of Adam (Michelangelo) | Symbol of life, spark of divine consciousness |
| The Cathedral (Rodin) | Two hands form an arch — intimacy and human connection |
| Da Vinci’s drawings | Merge of anatomical accuracy and expressive motion |
9. Notable Figures
| Name | Contribution |
|---|---|
| Leonardo da Vinci | Anatomical drawings of hand musculature and mechanics |
| Sterling Bunnell | Founder of reconstructive hand surgery |
| Wilhelm Röntgen | First medical X-ray image: hand |
10. Quotes
| Quote | Author |
|---|---|
| “The hand is the visible part of the brain.” | Immanuel Kant |
| “The human hand is a most exquisite instrument.” | Charles Bell |
| “With these hands, we built civilizations.” | Unknown |
| “The hand is the tool of tools.” | Aristotle |
7. MCQ's
Page 6 – MCQs
Basic Science MCQ 1
Which nerve supplies the thenar muscles of the hand?
A. Ulnar nerve
B. Median nerve
C. Radial nerve
D. Axillary nerve
Correct Answer Table
| Correct Answer | Explanation |
|---|---|
| B. Median nerve | The median nerve innervates most of the thenar muscles including abductor pollicis brevis, opponens pollicis, and part of flexor pollicis brevis. |
Incorrect Answer Table
| Choice | Why Incorrect |
|---|---|
| A. Ulnar nerve | Supplies hypothenar muscles and medial lumbricals, not the thenar group. |
| C. Radial nerve | Provides sensation to dorsum of hand but no motor innervation to intrinsic hand muscles. |
| D. Axillary nerve | Innervates deltoid and teres minor; not involved in hand function. |
Basic Science MCQ 2
Which of the following bones is most commonly fractured in the hand?
A. Capitate
B. Lunate
C. Scaphoid
D. Pisiform
Correct Answer Table
| Correct Answer | Explanation |
|---|---|
| C. Scaphoid | The scaphoid is the most frequently fractured carpal bone, typically injured in a fall on an outstretched hand (FOOSH). |
Incorrect Answer Table
| Choice | Why Incorrect |
|---|---|
| A. Capitate | Rarely fractured due to its central, protected position. |
| B. Lunate | More commonly dislocated than fractured. |
| D. Pisiform | Least likely to fracture among the carpal bones. |
Clinical MCQ 1
A patient presents with finger locking and pain in the palm. What is the most likely diagnosis?
A. De Quervain’s tenosynovitis
B. Trigger finger
C. Dupuytren’s contracture
D. Carpal tunnel syndrome
Correct Answer Table
| Correct Answer | Explanation |
|---|---|
| B. Trigger finger | Caused by stenosing tenosynovitis of the flexor tendon sheath, resulting in finger locking and snapping. |
Incorrect Answer Table
| Choice | Why Incorrect |
|---|---|
| A. De Quervain’s | Affects the thumb extensor tendons at the radial styloid, not the digits. |
| C. Dupuytren’s | Causes progressive flexion deformity but not locking. |
| D. Carpal tunnel syndrome | Causes numbness and weakness, not mechanical locking. |
Clinical MCQ 2
Which test is used to assess blood flow in the palmar arches before cannulating the radial artery?
A. Froment’s sign
B. Phalen’s test
C. Allen’s test
D. Tinel’s sign
Correct Answer Table
| Correct Answer | Explanation |
|---|---|
| C. Allen’s test | Evaluates collateral circulation from the ulnar artery before procedures involving the radial artery. |
Incorrect Answer Table
| Choice | Why Incorrect |
|---|---|
| A. Froment’s sign | Assesses ulnar nerve palsy via thumb flexion. |
| B. Phalen’s test | Screens for carpal tunnel syndrome. |
| D. Tinel’s sign | Identifies nerve irritation, not blood flow. |
Radiologic MCQ 1
Which imaging modality best evaluates tendon motion in the hand in real-time?
A. X-ray
B. CT scan
C. Ultrasound
D. MRI
Correct Answer Table
| Correct Answer | Explanation |
|---|---|
| C. Ultrasound | Provides dynamic, real-time imaging of tendons during motion. Useful for diagnosing trigger finger or tenosynovitis. |
Incorrect Answer Table
| Choice | Why Incorrect |
|---|---|
| A. X-ray | Evaluates bone, not soft tissue motion. |
| B. CT scan | Great for bone detail but not soft tissue movement. |
| D. MRI | Shows soft tissues but is static, not dynamic. |
Radiologic MCQ 2
Which radiographic view is most appropriate for visualizing a suspected scaphoid fracture?
A. Lateral wrist view
B. PA hand view
C. Scaphoid view (ulnar deviation)
D. Oblique elbow view
Correct Answer Table
| Correct Answer | Explanation |
|---|---|
| C. Scaphoid view (ulnar deviation) | Positions the scaphoid more clearly across the imaging plane, improving detection of fractures. |
Incorrect Answer Table
| Choice | Why Incorrect |
|---|---|
| A. Lateral wrist view | Useful for alignment but not optimal for scaphoid detail. |
| B. PA hand view | Includes the scaphoid but not isolated well. |
| D. Oblique elbow view | Irrelevant to the carpal bones. |
Radiologic MCQ 3
What is the most common finding on X-ray in a patient with advanced rheumatoid arthritis of the hand?
A. Bone island
B. Joint space narrowing with ulnar deviation
C. Osteoblastic lesions
D. Posterior dislocation of the wrist
Correct Answer Table
| Correct Answer | Explanation |
|---|---|
| B. Joint space narrowing with ulnar deviation | RA commonly causes symmetric joint space loss and deformities including ulnar deviation of the MCP joints. |
Incorrect Answer Table
| Choice | Why Incorrect |
|---|---|
| A. Bone island | Benign, unrelated finding. |
| C. Osteoblastic lesions | Seen in metastases, not RA. |
| D. Posterior dislocation | Not a typical feature of RA. |
8. Memory Image
Page 7 – Memory Image
| Memory Image | Caption and Interpretation |
|---|---|
| (AI-generated image of an open human hand, each finger transforming into a functional tool: pliers, flashlight, scalpel, brush, and stylus.) | Caption: Each digit of the hand is represented as a tool, reflecting its multifunctional capacity: strength, sensation, precision, expression, and creativity. Interpretation: The hand is not only a physical structure but a composite of purpose-built units, each performing coordinated tasks to interact with the world. It reflects the union of anatomy and identity. |