Hand And Or Wrist Injuries

Introduction to MCCQE1 Preparation

Hand and wrist injuries are extremely common presentations in Canadian Emergency Departments and Family Medicine clinics. For the MCCQE1, candidates are expected to demonstrate the Medical Expert role by diagnosing and managing common fractures, ligamentous injuries, and overuse syndromes. Furthermore, the Communicator and Collaborator roles are vital when discussing return-to-work plans (often involving WSIB/WorkSafe) and referrals to orthopedic or plastic surgery.

This guide focuses on high-yield pathologies, distinguishing features, and Canadian-specific management guidelines to help you excel in your MCCQE1 preparation.

Functional Anatomy & Physical Exam

A systematic approach to the hand and wrist exam is crucial. Failure to identify specific deficits can lead to permanent disability.

Common Fractures and Dislocations

Scaphoid Fracture

This is the most common carpal bone fracture and a very high-yield topic for the MCCQE1 due to the risk of complications.

Distal Radius Fractures

Differentiating between Colles and Smith fractures is essential for the exam.

Boxer’s Fracture

• Definition: Fracture of the 5th Metacarpal neck.
• Mechanism: Punching a solid object.
• Management:
  • Assess for rotation (fingers should point to scaphoid when flexed).
  • Ulnar Gutter Splint if stable and minimal angulation (<40 degrees for 5th MC).
  • Bite Wounds: If skin is broken over the knuckle (fight bite), treat as an open fracture. Eikenella corrodens coverage (Amoxicillin-Clavulanate) is required.

Soft Tissue and Overuse Injuries

De Quervain’s Tenosynovitis

Stenosing tenosynovitis of the first dorsal compartment (APL and EPB tendons).

• Population: New mothers (lifting baby), repetitive thumb users.
• Test: Finkelstein’s test (Patient makes fist with thumb inside, examiner deviates wrist ulnarward).
• Treatment: NSAIDs, Thumb Spica splint, Steroid injection.

Carpal Tunnel Syndrome (CTS)

Compression of the median nerve at the wrist.

• Symptoms: Paresthesia in radial 3.5 digits, nocturnal pain, thenar atrophy (late sign).
• Risk Factors: Pregnancy, Hypothyroidism, Diabetes, Rheumatoid Arthritis, Repetitive use.
• Diagnosis: Clinical (Phalen’s/Tinel’s). EMG/NCS is the gold standard for confirmation/severity grading.
• Management:
  1. Wrist splints (neutral position) mostly at night.
  2. Steroid injection.
  3. Surgical release (if refractory or thenar atrophy present).

Mallet Finger vs. Jersey Finger

These represent opposite injuries to the DIP joint mechanism.

Canadian Guidelines & Clinical Context

When preparing for the MCCQE1, understand how Canadian healthcare resources influence management.

Choosing Wisely Canada

Recommendations relevant to hand/wrist:

• Don’t order MRI for suspected scaphoid fractures unless plain films are normal and clinical suspicion remains high, and the results will alter management (e.g., return to work/sport).
• Don’t order X-rays for simple subungual hematoma if the nail edge is intact and there is no significant deformity (though practice varies).

Workplace Injuries (WSIB/WorkSafe)

In Canada, hand injuries are a leading cause of lost-time claims.

• Form 8 (or provincial equivalent): Physicians must complete initial reports for work-related injuries.
• Return to Work: Prioritize “modified duties” over complete rest when safe, to maintain connection to the workplace.

Referral Criteria (Orthopedics/Plastics)

• Open fractures.
• Neurovascular compromise.
• Intra-articular fractures with step-off >2mm.
• Unstable fractures (e.g., Smith’s, displaced Scaphoid).
• Flexor tendon injuries.
• High-pressure injection injuries (Surgical Emergency).

Key Points to Remember for MCCQE1

• Scaphoid Tenderness: Treat as a fracture until proven otherwise (Thumb Spica + follow-up).
• Bite Wounds: “Fight bites” require antibiotics covering Eikenella and Staph aureus. Never close these wounds primarily.
• Compartment Syndrome: Pain out of proportion to injury, pain on passive stretch. Urgent fasciotomy.
• Gamekeeper’s Thumb: Ulnar Collateral Ligament (UCL) injury. Test stability. If unstable (>30 deg laxity or no endpoint), requires surgery (Stener lesion).
• Amputated Digits: Wrap part in saline-moistened gauze, place in a watertight bag, and place that bag on ice (do not place part directly on ice or in water).

Sample Question

Clinical Scenario

A 24-year-old male presents to the Emergency Department after falling on an outstretched hand while playing hockey. He complains of pain in his right wrist. On physical examination, there is no obvious deformity, but he has significant tenderness in the anatomical snuffbox and pain with axial loading of the thumb. Neurovascular status is intact. An initial radiograph of the wrist, including scaphoid views, shows no evidence of fracture.

Question

Which one of the following is the most appropriate next step in management?

• A. Reassure the patient and discharge with NSAIDs
• B. Apply a short arm thumb spica splint and arrange for repeat X-rays in 10 to 14 days
• C. Order an immediate MRI of the wrist to rule out fracture
• D. Apply a compression bandage and encourage early range of motion exercises
• E. Order a bone scan to be performed within 24 hours

Explanation

The correct answer is:

• B. Apply a short arm thumb spica splint and arrange for repeat X-rays in 10 to 14 days

Detailed Explanation: This clinical scenario is classic for a suspected scaphoid fracture. The scaphoid is the most commonly fractured carpal bone, typically resulting from a fall on an outstretched hand (FOOSH).

• Why B is correct: Scaphoid fractures are notorious for being “occult” on initial X-rays (up to 20% are not visible immediately). Due to the retrograde blood supply of the scaphoid, missed fractures can lead to avascular necrosis and non-union. Therefore, the standard of care (and the MCCQE1 keyed response) for a patient with clinical signs of a scaphoid fracture (snuffbox tenderness) but negative X-rays is to immobilize (thumb spica splint/cast) and re-evaluate with repeat imaging in 10-14 days. By that time, bone resorption at the fracture site usually makes the fracture line visible.

• Why A and D are incorrect: Discharging without immobilization risks fracture displacement and non-union complications. Early motion is contraindicated if a fracture is suspected.

• Why C is incorrect: While MRI is the gold standard for immediate diagnosis and is used in some settings (e.g., professional athletes or where resources allow), the most appropriate initial step in the general Canadian context, given resource stewardship and standard guidelines, is immobilization and follow-up. MRI is typically reserved for cases where the diagnosis remains unclear after follow-up or for immediate return-to-work decisions in specific high-demand populations.

• Why E is incorrect: Bone scans are sensitive but less specific and involve radiation and delay. They are rarely the first-line choice in the acute setting given the availability of CT/MRI if advanced imaging is truly needed later.

References

1. Medical Council of Canada. MCCQE Part I Clinical Decision-Making and Multiple-Choice Question Guidelines.
2. Choosing Wisely Canada. Emergency Medicine and Orthopedics recommendations. Link 
3. Canadian Orthopaedic Association. Clinical Practice Guidelines.
4. UpToDate. Scaphoid fractures: Clinical manifestations and diagnosis.
5. Toronto Notes 2024. Orthopedics Chapter: Hand and Wrist.
6. WorkSafeBC. Evidence-Based Practice Group: Diagnosis and Treatment of Scaphoid Fractures.