The Human Hand: Anatomy, Physiology, Disorders & Treatment Guide

1. Introduction

• The hand is one of the most complex and functional parts of the human body, allowing grasping, fine motor control, and sensory perception.
• It consists of 27 bones, numerous muscles, tendons, nerves, and blood vessels.
• Common hand disorders include fractures, carpal tunnel syndrome, arthritis, and tendon injuries.

2. Anatomy of the Hand

• Bones (27 Total):
  • Carpals (8): Wrist bones (e.g., scaphoid, lunate, trapezium).
  • Metacarpals (5): Bones of the palm.
  • Phalanges (14): Finger bones (proximal, middle, distal).
• Joints:
  • Wrist (Radiocarpal) Joint: Connects hand to forearm.
  • Metacarpophalangeal (MCP) Joints: Knuckles.
  • Interphalangeal (IP) Joints: Finger bending joints.
• Muscles & Tendons:
  • Flexor Tendons: Bend the fingers.
  • Extensor Tendons: Straighten the fingers.
  • Thenar & Hypothenar Muscles: Control thumb and pinky movement.
• Nerves:
  • Median Nerve: Controls thumb, index, middle fingers.
  • Ulnar Nerve: Controls ring and pinky fingers.
  • Radial Nerve: Controls back of hand and wrist extension.
• Blood Supply:
  • Radial & Ulnar Arteries: Provide circulation to the hand.

3. Physiology of the Hand

• Fine Motor Skills:
  • The hand allows precise movements like writing, typing, and grasping.
• Grip Strength & Dexterity:
  • Different types of grips (power grip, precision grip) allow for various tasks.
• Sensory Function:
  • The fingertips have a high density of Meissner’s corpuscles, making them highly sensitive to touch.
• Thermoregulation:
  • Blood vessels help regulate temperature by adjusting blood flow.

4. Common Disorders & Pathophysiology

A. Carpal Tunnel Syndrome (CTS)

• Cause: Compression of the median nerve in the wrist.
• Risk Factors: Repetitive hand movements, pregnancy, diabetes.

B. Arthritis

• Types:
  • Osteoarthritis (OA): Wear-and-tear damage.
  • Rheumatoid Arthritis (RA): Autoimmune joint inflammation.
• Symptoms: Joint pain, stiffness, swelling.

C. Trigger Finger (Stenosing Tenosynovitis)

• Cause: Inflammation of the flexor tendon sheath.
• Symptoms: Finger gets stuck in a bent position.

D. Fractures & Dislocations

• Common Types:
  • Scaphoid Fracture: Common in wrist falls.
  • Boxer’s Fracture: Break in metacarpals from punching.
• Risk Factors: Falls, contact sports, osteoporosis.

E. Tendon Injuries (Tendonitis, Ruptures)

• De Quervain’s Tenosynovitis: Pain in the thumb side of the wrist.
• Flexor/Extensor Tendon Ruptures: Affect grip and hand function.

5. Signs & Symptoms of Hand Disorders

• Early Symptoms:
  • Tingling, numbness in fingers (CTS).
  • Joint stiffness (arthritis).
• Advanced Symptoms:
  • Weak grip, dropping objects.
  • Visible deformity or swelling.
• Red Flags:
  • Sudden severe pain after injury.
  • Loss of movement in fingers.
  • Persistent numbness (nerve damage).

6. When to See a Doctor

• Persistent hand pain lasting more than 2 weeks.
• Weakness or numbness in the fingers.
• Joint swelling that does not improve with rest.

7. Emergency Signs Requiring Immediate Care

• Open wounds with exposed bone/tendons.
• Severe swelling, bruising, or inability to move fingers.
• Signs of infection (redness, warmth, pus).

8. Diagnostic Process

• Clinical Examination:
  • Grip strength testing.
  • Sensory testing for nerve function.
• Laboratory Tests:
  • Rheumatoid Factor (RF), Anti-CCP: For rheumatoid arthritis.
  • Inflammatory Markers (CRP, ESR): For systemic conditions.
• Imaging Tests:
  • X-ray: Identifies fractures, arthritis.
  • MRI: Detects tendon and ligament injuries.
  • Nerve Conduction Study (NCS): Confirms carpal tunnel syndrome.
• Specialist Procedures:
  • Joint Aspiration: Removes fluid for arthritis diagnosis.

9. Likely Diagnoses

• Carpal Tunnel Syndrome (CTS).
• Osteoarthritis or Rheumatoid Arthritis.
• Fractures or Dislocations.
• Tendonitis or Tendon Ruptures.
• Trigger Finger.

10. Treatment Options

A. Medications

• For Pain & Inflammation:
  • NSAIDs (Ibuprofen, Naproxen).
  • Acetaminophen (Paracetamol).
• For Arthritis:
  • DMARDs (Methotrexate, Hydroxychloroquine) for RA.
  • Biologic Therapies (Adalimumab, Etanercept).
• For Carpal Tunnel Syndrome:
  • Corticosteroid Injections (Methylprednisolone).
• For Infections:
  • Antibiotics (Amoxicillin-Clavulanate) for bacterial infections.
• Approximate Medication Costs (USD):
  • NSAIDs: $10–$50 per month.
  • DMARDs: $100–$500 per month.
  • Corticosteroid Injections: $50–$200 per dose.

B. Surgical/Procedural Interventions

• Carpal Tunnel Release Surgery ($3,000–$7,000).
• Joint Replacement (For Severe Arthritis) ($10,000–$30,000).
• Tendon Repair Surgery ($5,000–$15,000).
• Fracture Fixation (Pins, Plates) ($3,000–$10,000).

C. Lifestyle Modifications & Home Remedies

• For Carpal Tunnel & Tendonitis:
  • Wrist splints, ergonomic workspaces.
• For Arthritis:
  • Heat/cold therapy, hand exercises.
• For General Hand Health:
  • Strengthening exercises, avoiding repetitive strain.

11. Precautions & Prevention

• Use Proper Ergonomics: Reduce repetitive strain injuries.
• Wear Protective Gear: Prevent fractures in sports.
• Maintain Joint Health: Stay active, eat an anti-inflammatory diet.

12. Prognosis & Recovery

• Carpal Tunnel Syndrome: Symptoms improve with surgery.
• Arthritis: Progressive but manageable.
• Fractures: Heal in 6–8 weeks with immobilization.
• Tendon Injuries: Recovery takes 3–6 months, depending on severity.

13. Cost of Treatment

• X-ray: $100–$500.
• MRI: $1,000–$5,000.
• Carpal Tunnel Surgery: $3,000–$7,000.
• Hand Therapy (Physiotherapy): $50–$200 per session.

14. Frequently Asked Questions (FAQs)

1. Why do my hands tingle at night?
   • Possible carpal tunnel syndrome.
2. Can arthritis be reversed?
   • Osteoarthritis cannot, but rheumatoid arthritis can be controlled.
3. How do I strengthen my grip?
   • Hand exercises, squeezing a stress ball.
4. Is cracking knuckles bad for the joints?
   • No proven damage, but excessive cracking may loosen ligaments.
5. What is the best treatment for carpal tunnel syndrome?
   • Wrist splints, NSAIDs, surgery if severe.
6. How long does it take for a fractured hand to heal?
   • 6–8 weeks with proper immobilization.
7. What causes trigger finger?
   • Thickening of the tendon sheath, often due to overuse.
8. Can poor circulation cause hand pain?
   • Yes, especially in conditions like Raynaud’s disease.
9. Is hand surgery risky?
   • Risks include infection, stiffness, and nerve damage.
10. How can I prevent tendon injuries?

• Avoid repetitive strain, stretch regularly.