Applied Anatomy – Hand
1. Definition Table
| Category | Explanation |
|---|---|
| What is it? | – Complex structure at the distal end of the upper limb – Specialized for manipulation, sensation, and fine motor control |
| Most unique feature | – Extraordinary dexterity and sensitivity – Opposable thumb enabling precision grip |
| Structurally characterized by | – 27 bones divided into carpal bones (wrist), metacarpals (palm), and phalanges (fingers) – Intricate network of tendons, ligaments, nerves, and blood vessels |
| Functionally characterized by | – Enables grasping, holding, pinching, and sensory exploration – Critical for communication (gestures, writing) and tool use |
| Composed of | – Carpals (8): Scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate, hamate – Metacarpals (5): Hand bones – Phalanges (14): Fingers and thumb (proximal, middle, distal) |
| Common diseases | – Fractures (scaphoid, metacarpal, phalanges) – Carpal tunnel syndrome – Tendon injuries (e.g., flexor/extensor tendon rupture) – Osteoarthritis and rheumatoid arthritis |
| Diagnosis – Clinical | – Pain, swelling, deformity – Loss of grip strength – Sensory changes (numbness, tingling) |
| Diagnosis – Imaging | – X-ray: First-line for fractures – MRI: Soft tissue injuries (tendons, ligaments, nerves) – Ultrasound: Dynamic tendon and vascular evaluation |
| Diagnosis – Labs | – ESR, CRP, rheumatoid factor for inflammatory arthritis – CBC if infection suspected |
| Treatment (Rx) | – Splinting or casting for fractures – Surgical repair for displaced fractures or tendon injuries – Steroid injections for inflammatory conditions – Physical therapy for functional recovery |
2. Parts Table
| Part | Description |
|---|---|
| Carpal bones | – 8 small bones forming the wrist – Two rows: Proximal (scaphoid, lunate, triquetrum, pisiform); Distal (trapezium, trapezoid, capitate, hamate) |
| Metacarpals | – 5 bones forming the skeleton of the palm – Numbered 1–5 from thumb to little finger |
| Phalanges | – 14 bones – Each finger has 3 phalanges (proximal, middle, distal) – Thumb has 2 phalanges (proximal and distal) |
| Thumb (Pollex) | – Most mobile digit – Allows opposition and precision grip |
| Tendons | – Flexor tendons on palmar side (gripping) – Extensor tendons on dorsal side (releasing) |
| Ligaments | – Maintain stability between bones – Important for joint integrity |
| Nerves | – Median, ulnar, and radial nerves supply motor and sensory innervation |
3. Historical Note
| Era | Highlights |
|---|---|
| Ancient Times | – Early splinting of hand injuries in Egyptian medicine – Recognition of importance of thumb in gripping by Aristotle |
| Classical Era | – Galen described anatomy of tendons, nerves, and muscles of the hand – Early understanding of hand deformities |
| Modern Era | – Development of microsurgical techniques for tendon and nerve repair – Advancements in imaging for diagnosing soft tissue injuries – Hand surgery became a specialized field (pioneered in WW2 era) |
4. MCQs
🧠 Basic Science
Q1: How many carpal bones are present in each hand?
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A. 6
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B. 7
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C. 8
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D. 9
Answer: C. 8
Explanation:
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8 (Correct): Arranged in two rows of four bones each.
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6 (Incorrect): Too few.
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7 (Incorrect): Incomplete set.
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9 (Incorrect): Extra bone count.
Q2: Which bone is most commonly fractured in the wrist?
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A. Lunate
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B. Scaphoid
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C. Capitate
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D. Hamate
Answer: B. Scaphoid
Explanation:
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Scaphoid (Correct): Located at the base of the thumb; prone to fracture during falls.
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Lunate (Incorrect): More commonly associated with dislocations.
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Capitate (Incorrect): Rarely fractured.
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Hamate (Incorrect): Less common fracture site.
🩺 Clinical
Q3: Compression of the median nerve at the wrist causes:
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A. Carpal tunnel syndrome
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B. De Quervain’s tenosynovitis
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C. Ulnar nerve entrapment
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D. Radial nerve palsy
Answer: A. Carpal tunnel syndrome
Explanation:
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Carpal tunnel syndrome (Correct): Caused by compression of the median nerve under the flexor retinaculum.
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De Quervain’s tenosynovitis (Incorrect): Affects the tendons of the thumb, not a nerve compression.
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Ulnar nerve entrapment (Incorrect): Occurs at the elbow or wrist (Guyon’s canal).
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Radial nerve palsy (Incorrect): Causes wrist drop, unrelated to median nerve.
Q4: Which feature is most commonly affected in rheumatoid arthritis of the hand?
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A. Thumb CMC joint<br>- B. MCP (metacarpophalangeal) joints<br>- C. DIP (distal interphalangeal) joints<br>- D. Carpal bones
Answer: B. MCP joints
Explanation:
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MCP joints (Correct): Preferentially involved in rheumatoid arthritis leading to deformities.
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Thumb CMC joint (Incorrect): Commonly involved in osteoarthritis.
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DIP joints (Incorrect): Typically involved in osteoarthritis.
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Carpal bones (Incorrect): May be affected later but not primarily.
🖼️ Imaging
Q5: What is the imaging study of choice for evaluating flexor tendon injury?
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A. X-ray
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B. MRI
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C. CT scan
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D. Bone scan
Answer: B. MRI
Explanation:
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MRI (Correct): Best modality for soft tissue injuries like tendons.
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X-ray (Incorrect): Primarily for bone fractures.
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CT scan (Incorrect): Bone-focused imaging, limited for tendons.
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Bone scan (Incorrect): Metabolic activity evaluation, not ideal for tendons.
Q6: Which view on X-ray best visualizes scaphoid fractures?
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A. Lateral wrist view
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B. Anteroposterior wrist view
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C. Oblique wrist view
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D. Scaphoid (navicular) view
Answer: D. Scaphoid (navicular) view
Explanation:
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Scaphoid view (Correct): Specifically angled to better visualize scaphoid fractures.
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Lateral wrist view (Incorrect): Good for alignment, not optimal for scaphoid.
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Anteroposterior wrist view (Incorrect): General overview; may miss scaphoid fractures.
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Oblique wrist view (Incorrect): Helps but not best for scaphoid detail.
5. Memory Image Idea 💡
| Concept | Components |
|---|---|
| The Living Toolbox | – Visualize the hand as a versatile toolbox – Carpal bones = small gears and pivots in the toolbox lid (wrist motion) – Metacarpals = support beams of the toolbox (palm strength) – Phalanges = fine instruments (pliers, tweezers) inside the toolbox – Thumb = the universal tool that can grip or oppose everything – The box opens and closes, adapting tools for any job – Title: “The Living Toolbox – TheCommonVein.com“ |