DISTAL RADIUS FRACTURES: HIGH-YIELD BOARD REVIEW

This comprehensive guide synthesizes AAOS/ASSH 2022 evidence-based guidelines 1111111 with contemporary evidence to optimize morbidity, mortality, and quality of life outcomes.

1. VISUAL MIND MAP: HIERARCHICAL TREE

DISTAL RADIUS FRACTURES
│
├── ANATOMY: 3-COLUMN THEORY
│   ├── Radial Column (Radial styloid)
│   ├── Intermediate Column (Lunate fossa - central articular surface)
│   └── Ulnar Column (DRUJ, sigmoid notch, ulnar styloid)
│
├── MECHANISM OF INJURY
│   ├── Low Energy: FOOSH (Fall On Outstretched Hand) - elderly, osteoporotic
│   └── High Energy: MVA, sports - younger patients, comminuted patterns
│
├── EPONYMOUS FRACTURES
│   ├── Colles: Dorsal angulation, dorsal displacement, extra-articular
│   ├── Smith (Reverse Colles): Volar angulation, volar displacement
│   ├── Barton: Intra-articular rim fracture with carpal subluxation
│   │   ├── Volar Barton (more common)
│   │   └── Dorsal Barton
│   ├── Chauffeur (Radial Styloid): Isolated radial styloid avulsion
│   └── Die-Punch: Depressed lunate fossa (central articular impaction)
│
└── AO/OTA CLASSIFICATION
    ├── Type A: Extra-articular
    │   ├── A1: Ulna intact, radius extra-articular
    │   ├── A2: Ulna fractured, radius extra-articular simple
    │   └── A3: Radius extra-articular multifragmentary
    ├── Type B: Partial articular (one cortex intact)
    │   ├── B1: Sagittal fracture
    │   ├── B2: Dorsal rim (Barton)
    │   └── B3: Volar rim (Reverse Barton)
    └── Type C: Complete articular (both cortices disrupted)
        ├── C1: Articular simple, metaphyseal simple
        ├── C2: Articular simple, metaphyseal comminuted
        └── C3: Articular comminuted (worst prognosis)

2. RADIOGRAPHIC PARAMETERS: INFOGRAPHIC TABLE

Parameter	Normal Value	Acceptable Post-Reduction	Clinical Pearl
Radial Height	11-13 mm	Loss <3 mm	>5 mm loss = DRUJ instability, poor grip
Radial Inclination	22-23°	>15°	<15° = ulnar impaction syndrome
Volar Tilt	11-12° volar	Neutral to 5° dorsal acceptable in elderly; <10° dorsal in young/active	>10° dorsal = DRUJ instability, poor outcomes
Articular Step-off	0 mm	<2 mm	>2 mm = post-traumatic arthritis risk
Ulnar Variance	Neutral (±1 mm)	Maintain pre-injury variance	Positive variance = ulnar impaction

Key Instability Predictors (Lafontaine Criteria - ≥3 = unstable):

Dorsal comminution
Dorsal angulation >20°
Intra-articular involvement
Associated ulnar fracture
Age >60 years
Radial shortening >5 mm

3. MANAGEMENT ALGORITHM: DECISION TREE

ACUTE DISTAL RADIUS FRACTURE
│
├─→ INITIAL ASSESSMENT
│   ├── Check neurovascular status (median nerve most common)
│   ├── Assess soft tissue (open fracture, compartment syndrome)
│   ├── Obtain PA, Lateral, Oblique X-rays
│   └── CT if intra-articular comminution suspected
│
├─→ FRACTURE CLASSIFICATION
│   ├── Extra-articular vs Intra-articular
│   ├── Displaced vs Non-displaced
│   └── Apply Lafontaine Criteria
│
├─→ TREATMENT DECISION
│   │
│   ├── NON-DISPLACED / MINIMALLY DISPLACED
│   │   └─→ CONSERVATIVE MANAGEMENT
│   │       ├── Sugar-tong splint initially (controls pronation/supination)
│   │       ├── Convert to short-arm cast at 1 week
│   │       ├── Weekly X-rays × 3 weeks (monitor displacement)
│   │       └── Total immobilization: 4-6 weeks
│   │
│   ├── DISPLACED BUT REDUCIBLE + LOW DEMAND (elderly, low activity)
│   │   └─→ CLOSED REDUCTION & CASTING
│   │       ├── Hematoma block / procedural sedation
│   │       ├── Reduction maneuver: Traction → Disimpaction → Correct angulation
│   │       ├── Mold cast: 3-point pressure (volar distal, dorsal proximal/middle)
│   │       ├── Accept: Neutral to 5° dorsal tilt in elderly [1][1]
│   │       └── Weekly X-rays × 3 weeks
│   │
│   └── SURGICAL INDICATIONS (any of the following):
│       ├── Unstable fracture (≥3 Lafontaine criteria)
│       ├── Irreducible fracture
│       ├── Open fracture
│       ├── Young/high-demand patient with displacement
│       ├── Post-reduction loss of parameters (see table above)
│       └── Intra-articular step-off >2 mm
│
└─→ SURGICAL TECHNIQUE SELECTION
    │
    ├── VOLAR LOCKING PLATE (VLP) - **GOLD STANDARD** [1][2]
    │   ├── Indications: Most unstable fractures, intra-articular, high demand
    │   ├── Advantages: Rigid fixation, early mobilization, best functional outcomes
    │   ├── Approach: Henry (FCR-radial artery interval)
    │   └── Pitfalls: Flexor tendon irritation, screw penetration
    │
    ├── PERCUTANEOUS K-WIRES
    │   ├── Indications: Extra-articular, elderly low-demand, cost-limited settings [2]
    │   ├── Advantages: Minimally invasive, cost-effective
    │   └── Disadvantages: Pin tract infection, requires 4-6 weeks immobilization
    │
    ├── EXTERNAL FIXATION
    │   ├── Indications: Severe comminution, open fractures, soft tissue compromise
    │   ├── Technique: Ligamentotaxis for reduction
    │   └── Often combined with K-wires or fragment-specific fixation
    │
    └── DORSAL PLATING
        ├── Indications: Dorsal Barton, dorsal shear fractures
        └── Caution: EPL tendon rupture risk (remove hardware at 6-12 months)

4. COMPLICATIONS & CLINICAL PEARLS

MAJOR COMPLICATIONS

A. EPL TENDON RUPTURE (Extensor Pollicis Longus)

Incidence: 3-5% of distal radius fractures
Mechanism: Ischemia from fracture hematoma in 3rd dorsal compartment OR hardware irritation (dorsal plates)
Timing: Typically 4-8 weeks post-injury (can occur even with conservative treatment)
Clinical Pearl:
- Test EPL function at every follow-up (thumb IP extension against resistance)
- If dorsal plating used, remove hardware at 6-12 months
- Warn patients preoperatively about this risk
Management: EIP-to-EPL tendon transfer

B. MEDIAN NERVE NEUROPATHY / ACUTE CARPAL TUNNEL SYNDROME

Incidence: 5-15% acute compression, up to 30% chronic symptoms
Risk Factors: High-energy fractures, severe displacement, hematoma
Clinical Pearl:
- Document median nerve function pre-reduction (thenar strength, 2-point discrimination)
- Emergent carpal tunnel release if acute CTS (within 6-8 hours)
- Post-operative CTS from hematoma/swelling: release if no improvement in 24-48 hours
- Prophylactic CTR controversial but consider in high-risk fractures 1

C. MALUNION

Definition: Healed fracture with unacceptable alignment (see radiographic table)
Consequences:
- Dorsal malunion >10°: DRUJ instability, weak grip, pain
- Radial shortening >3 mm: Ulnar impaction, TFCC injury
- Intra-articular step-off >2 mm: Post-traumatic arthritis
Clinical Pearl:
- Most common cause = inadequate initial reduction or loss of reduction in cast
- Weekly X-rays × 3 weeks mandatory for all non-operative cases 1
- If displacement occurs, convert to surgery within 2 weeks (before callus formation)
Management: Corrective osteotomy if symptomatic (typically after 6-12 months)

D. COMPLEX REGIONAL PAIN SYNDROME (CRPS) Type I

Incidence: 10-25% (most underdiagnosed complication)
Budapest Criteria: Pain + sensory/vasomotor/sudomotor/motor changes
Clinical Pearl:
- Prevention is key: Early mobilization, vitamin C 500 mg daily × 50 days (moderate evidence) 1
- Avoid overly tight casts/dressings
- Aggressive hand therapy starting week 1-2 post-op
- If suspected: Early referral to pain specialist, consider stellate ganglion block
Management: Physical therapy, desensitization, gabapentin/pregabalin, sympathetic blocks

ADDITIONAL COMPLICATIONS & PEARLS

Complication	Incidence	Prevention Strategy	Management
Flexor Tendon Irritation (VLP)	5-10%	Plate positioning: Proximal to watershed line, smooth contouring	Hardware removal if symptomatic
Screw Penetration (dorsal cortex)	2-5%	Intra-op fluoroscopy: Lateral view, pronated oblique view, direct visualization	Screw exchange/removal
DRUJ Instability	10-15%	Restore radial height/volar tilt, assess DRUJ intra-op	TFCC repair, ulnar styloid fixation if >2 mm displaced
Stiffness	20-30%	Early mobilization (week 1-2), hand therapy	Aggressive PT, consider manipulation under anesthesia if <12 weeks
Infection (surgical)	<2%	Prophylactic antibiotics, sterile technique	Antibiotics, I&D if deep, hardware retention if stable

CRITICAL SURGICAL PEARLS: SAFE-VLP CHECKLIST 2

S - Safe Plate Position

Proximal to watershed line (avoid flexor tendon zone)
Distal screws within 3 mm of subchondral bone

A - Appropriate Screw Length

Check dorsal cortex penetration on lateral + pronated oblique views
Palpate dorsal cortex directly intra-op

F - Fixation Stability

Minimum 3 distal locking screws in distal fragment
Assess DRUJ stability after fixation

E - Early Rehabilitation

Start finger ROM immediately post-op
Wrist ROM at 2 weeks (if stable fixation)
Avoid heavy lifting × 6-8 weeks

AAOS 2022 GUIDELINE KEY RECOMMENDATIONS 1111111

Strong Evidence (Grade A):

Vitamin C supplementation (500 mg daily × 50 days) reduces CRPS incidence
Surgical fixation improves early functional outcomes in unstable fractures (but long-term outcomes converge with conservative management in elderly low-demand patients)

Moderate Evidence (Grade B):

Arthroscopic assistance may improve detection of intra-articular pathology (TFCC, scapholunate ligament injuries) but does not consistently improve functional outcomes 1
Volar locking plates provide superior stability compared to K-wires or external fixation for unstable fractures

Limited Evidence:

Optimal timing of surgery (early vs delayed within 2 weeks shows no difference)
Routine DRUJ assessment/fixation protocols

CONTEXT-SPECIFIC ALGORITHMS

Elderly Low-Demand Patient (>65 years, sedentary)

Accept more displacement: Neutral to 5° dorsal tilt, radial shortening <5 mm 12
Prefer conservative management unless:
- Intra-articular step-off >2 mm
- Severe comminution preventing cast stability
- Patient desires early return to activities
If surgery needed: Consider K-wires over VLP (cost-effective, equivalent long-term outcomes) 2

Young High-Demand Patient (<50 years, active/working)

Anatomic reduction mandatory: Restore all radiographic parameters
Low threshold for surgical fixation (VLP preferred)
Accept <2 mm articular step-off only if peripheral (not central lunate fossa)

Resource-Limited Settings (LMICs) 2

High-quality casting for stable/low-demand patients
Percutaneous K-wires for moderate instability (cost-effective alternative)
Day-surgery VLP for unstable/working-age patients
Tele-rehabilitation strategies to reduce follow-up burden

FOLLOW-UP PROTOCOL

Conservative Management:

Week 1: Clinical assessment, repeat X-rays (check reduction maintenance)
Week 2: Repeat X-rays
Week 3: Repeat X-rays (last critical window for displacement)
Week 6: Cast removal, X-rays, start hand therapy
Month 3: Final X-rays, assess union

Surgical Management:

Week 2: Wound check, start wrist ROM (if stable fixation)
Week 6: X-rays, advance strengthening
Month 3: X-rays, return to full activities if healed
Month 6-12: Consider hardware removal if symptomatic (especially dorsal plates)

BOTTOM LINE: The 2022 AAOS/ASSH guidelines 1111111 emphasize individualized treatment based on fracture stability (Lafontaine criteria), patient functional demand, and radiographic parameters. Volar locking plates remain the gold standard for unstable fractures in high-demand patients, while conservative management is appropriate for stable fractures and elderly low-demand patients with acceptable alignment. Early mobilization and vitamin C supplementation reduce CRPS risk. Weekly radiographic surveillance for 3 weeks is mandatory for all non-operative cases to detect early displacement requiring surgical conversion.

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