Exam Detail:

Key Revision Focus: Radiographic parameters (11mm height, 22° inclination, 11° volar tilt), Eponyms (Colles vs Smith vs Barton), Criteria for instability (Lafontaine), and EPL rupture mechanism. Understanding the DRUJ is critical.

1. Clinical Overview

Distal Radius Fractures are the most common orthopaedic injury, accounting for 17% of all fractures. They represent a bimodal distribution: high-energy trauma in young patients and low-energy fragility fractures in the osteoporotic elderly.

Clinical Pearl:

The Median Nerve Trap: Acute Carpal Tunnel Syndrome (CTS) is the most urgent complication. If a patient has increasing paresthesia/numbness after reduction, the splint must be loosened. If symptoms persist -> Carpal Tunnel Release (often with ORIF).

Key Concepts

1. Anatomy (3 Columns):
   • Radial Column: Radial styloid + Scaphoid fossa.
   • Intermediate Column: Lunate fossa + Sigmoid notch (Critical for load).
   • Ulnar Column: DRUJ + TFCC + Ulnar Styloid.
2. Eponyms:
   • Colles: Extra-articular, Dorsal displacement ("Dinner Fork"). Commonest.
   • Smith: Extra-articular, Volar displacement ("Garden Spade"). Unstable.
   • Barton: Intra-articular shear fracture (Volar or Dorsal). Must operate.
   • Chauffeur: Radial styloid avulsion (Intrinsic ligament injury attached).
   • Die-Punch: Depressed lunate fossa fracture.
3. Radiographic "Normal":
   • Radial Height: 11-12 mm.
   • Radial Inclination: 22 degrees.
   • Volar Tilt: 11 degrees.
4. Lafontaine Criteria (Predictors of Instability):
   • Dorsal comminution >50%.
   • Palmar comminution.
   • Initial dorsal angulation >20°.
   • Initial shortening >5mm.
   • Intra-articular involvement.
   • Age >60 (Osteoporosis).
5. Watershed Line: The limit for volar plate placement. Placing metal distal to this risks flexor tendon (FPL) rupture.
6. EPL Rupture: Extensor Pollicis Longus travels around Lister's tubercle. Can rupture weeks later due to attrition (assoc. with non-displaced fractures).

Clinical Pearls

• The "Soalr" View: A 22° elevated lateral view helps visualize the removal of screws from the joint surface (screw penetration).
• Ulnar Styloid: Associated in >50% of cases. Usually asymptomatic. Only fix if DRUJ is unstable after radius fixation.
• Complex Regional Pain Syndrome (CRPS): Vitamin C (500mg daily for 50 days) reduces risk from 10% to 2% (The ZOLCOT Trial debate, but standard practice).

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2. Epidemiology

• Incidence: Most common upper extremity fracture.
• Bimodal:
  • Young Males: High energy (MVA, fall from height).
  • Elderly Females: Low energy (Fall from standing height - FOOSH). Often the "Sentinel Fracture" signaling osteoporosis.
• Risk Factors: Osteoporosis, Female gender, Early menopause, propensity to fall.

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3. Pathophysiology

Mechanism

• FOOSH: Fall On Outstretched Hand.
  • Wrist extension (40-90 degrees) -> Colles.
  • Wrist flexion -> Smith.
• Energy Transfer: 80% of axial load goes through the Radius (Lunate/Scaphoid fossa), 20% through the Ulna (TFCC).

Deforming Forces

• Brachioradialis: Attaches to radial styloid. Pulls the distal fragment proximally (shortening) and into radial deviation.
• Extensors/Flexors: Cause dorsal/volar angulation.

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4. Clinical Presentation

• Deformity: "Dinner Fork" (Dorsal angulation) is classic.
• Swelling: Rapid onset.
• Neurovascular: Check Median Nerve (sensation to thumb/index/middle). Check Radial Pulse (cap refill).
• Skin: Check for tenting or open wounds (especially volar ulnar side - rare but high risk).

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5. Clinical Examination

1. Look:
   • Gross deformity.
   • Skin integrity (Open fracture?).
   • Swelling fingers (Ring removal).
2. Feel:
   • Tenderness generally global.
   • Check DRUJ tenderness (ballottement painful).
3. Move:
   • Painful. Do not force.
   • Check FPL/EPL function (thumbs up/bend thumb).
4. Neurovascular (The most important step):
   • Median Nerve: "OK sign" (Motor - AIN). Sensation tip of index.
   • Ulnar Nerve: Cross fingers (Motor). Sensation little finger.
   • Radial Nerve: Thumbs up (Motor). Sensation dorsal webspace.

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6. Investigations

X-ray (Trauma Series)

• PA View: Measure Height (11mm) and Inclination (22°).
• Lateral View: Measure Volar Tilt (11°). Check for Teardrop angle.
• Oblique View: Good for intra-articular stepping.

CT Scan

• Indicated for Intra-articular fractures (Barton, Die-punch).
• Evaluates step-off (>2mm predicts OA).
• Evaluates Sigmoid Notch (DRUJ) congruency.

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7. Management

Goal: Restore articular congruency (<2mm step) and anatomy to prevent OA and preserve rotation.

ASCII Algorithm:

          DISTAL RADIUS FRACTURE
                   ↓
┌──────────────────────────────────────┐
│        INITIAL MANAGEMENT            │
│ - Hematoma Block / Sedation          │
│ - Reduction (Traction + Molding)     │
│ - Sugar Tong / Backslab Splint       │
│ - Post-Reduction X-rays              │
└──────────────────────────────────────┘
                   ↓
┌──────────────────────────────────────┐
│           ACCEPTABLE?                │
│ (Height <5mm short, Tilt neutral,    │
│  Step <2mm, Inclin >15°)             │
├───────────────┬──────────────────────┤
│      YES      │          NO          │
└───────┬───────┴──────────┬───────────┘
        ↓                  ↓
┌───────────────┐  ┌───────────────────┐
│ CONSERVATIVE  │  │    SURGICAL       │
│ - Cast 6 wks  │  ├───────────────────┤
│ - Weekly Xray │  │ 1. Volar Plate    │
│               │  │    (Gold Std)     │
│               │  │ 2. K-Wires        │
│               │  │    (Kids/Simple)  │
│               │  │ 3. Bridge Plate   │
│               │  │    (Polytrauma)   │
│               │  │ 4. Ex-Fix         │
└───────────────┘  └───────────────────┘

1. Conservative Management

• Indication: Stable, extra-articular, elderly low demand, acceptable reduction.
• Reduction: Disengage fragments (traction) -> Palmar flex and Ulnar deviate (Colles).
• Immobilization: Below Elbow Cast in neutral/slight flexion. "Cotton Loader" position (extreme flexion/ulnar dev) is condemned (causes CTS and CRPS).
• Follow-up: X-ray weekly for 3 weeks. If it slips -> Surgery.

2. Surgical Management

A. Volar Locking Plate (VLP)

• The Workhorse.
• Approach: Modified Henry (FCR bed). Protect Median Nerve and Radial Artery.
• Mechanism: Fixed angle construct. Screws lock into plate, supporting the subchondral bone like a raft. Does not rely on bone purchase (good for osteoporosis).
• Watershed Line: Do not place plate distal to this prominent ridge or FPL will rub and rupture.

B. Dorsal Plating

• Indication: Specific dorsal rim fractures not reachable from volar.
• Cons: High rate of extensor tendon irritation/rupture.

C. K-Wires (Percutaneous)

• Indication: Young bone, simple extra-articular patterns.
• Technique: Kapandji intrafocal pinning vs Styloid pinning.
• Cons: Pin site infection, lacks rigid stability (cast needed).

D. External Fixation (Spanning)

• Indication: Massive comminution (ligamentotaxis resets fragments), Open fractures with soft tissue loss.

3. DRUJ Management

• After fixing radius, test DRUJ stability.
• Stable: Do nothing.
• Unstable:
  • Fix Ulnar Styloid (if large base fracture).
  • Pin DRUJ (supination) with K-wires for 4 weeks.
  • Immobilize in Sugar Tong (Supination) for 4 weeks.

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8. Complications

• Malunion: Shortening/Angulation -> Ulnar Impaction Syndrome (Ulnar-sided wrist pain).
• Median Nerve Neuropathy (Acute CTS):
  • Due to translation/pressure.
  • Management: Reduce fracture. If symptoms persist >24-48 hrs, release tunnel.
• EPL Rupture:
  • Painless inability to extend thumb IPJ.
  • Occurs 6-12 weeks post injury.
  • Attritional wear on Lister's tubercle or prominent screw.
  • Tx: EIP to EPL Transfer (Tendon transfer). Primary repair usually impossible (frayed).
• CRPS (Complex Regional Pain Syndrome):
  • Pain out of proportion, stiffness, glossy skin.
  • Prevention: Vitamin C 500mg. Early finger movement.
• FPL Rupture: Volar plate too distal (Watershed line violation).

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9. Prognosis & Outcomes

• Anatomic Reduction: Correlates with radiographic OA but not necessarily with functional outcome in the elderly (>65).
• Elderly: Functional outcomes of Cast vs Plate are often similar at 1 year, despite better X-rays with Plate. (DRAFFT Trial).
• Young: Anatomic reduction is mandatory to prevent OA.

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10. Evidence & Guidelines

Guidelines

• AAOS Guidelines: Strong recommendation for surgical fixation of unstable fractures. Vitamin C for CRPS prevention (Moderate strength).
• BOA Standards (UK): Fixation for intra-articular step >2mm or dorsal tilt >10 def in active patients.

Landmark Trials

• DRAFFT Trial (2014): Multicenter RCT. K-wires vs Volar Locking Plates for dorsally displaced fractures.
  • Result: No difference in PRWE (functional score) at 12 months.
  • Implication: K-wires are cheaper and quicker for simple patterns. However, modern practice still favors VLP for early mobilization. [PMID: 25186241]
• Arora et al (2011): Elderly patients (>65). Cast vs Plate.
  • Result: Plates gave better X-rays, but clinical range of motion and pain were the SAME at 1 year. Plates had more complications.
  • Implication: "Accept the malunion" in low-demand elderly. [PMID: 21653063]

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11. Patient Explanation

What is this fracture?

You have broken the end of the radius bone, the larger bone of the forearm that makes up the wrist. It is bent backwards ("Dinner Fork").

Do I need surgery?

It depends on 3 things:

1. Stability: Will it stay in place if we just pull it?
2. Surface: Is the joint surface smooth? If there is a step, it will grind (Arthritis).
3. You: Are you a violinist or active person? Or rarely use the hand?

The Plate Option

We make a cut on the palm side of the wrist. We put a titanium plate with screws to hold the bone in perfect position. The advantage is you can move the wrist sooner (often within 1-2 weeks) compared to a cast (6 weeks).

Risks

• Nerves: Numbness in the thumb/fingers (Carpal Tunnel) is possible.
• Tendons: The plate can irritate tendons. Rarely, the thumb tendon snaps (EPL rupture).
• Stiffness: Wrist stiffness is common regardless of treatment. Physiotherapy is key.

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12. References

1. Costa ML, et al. Percutaneous pinning versus volar locking-plate fixation for fractures of the distal radius in adults (DRAFFT): a multicentre, randomised controlled trial. BMJ. 2014 Aug 5;349:g4807. [PMID: 25186241]
2. Arora R, et al. A prospective randomized trial comparing nonoperative treatment with volar locking plate fixation for displaced and unstable distal radial fractures in patients sixty-five years of age and older. J Bone Joint Surg Am. 2011 Nov 16;93(22):2146-53. [PMID: 22090358]
3. Lafontaine M, et al. Instability of distal radial fractures. J Bone Joint Surg Br. 1989.
4. Orbay JL, Fernandez DL. Volar fixation for dorsally displaced fractures of the distal radius: a preliminary report. J Hand Surg Am. 2002 Mar;27(2):205-15. [PMID: 11901379]
5. ZOLCOT Trial: Zollinger PE, et al. Can vitamin C prevent complex regional pain syndrome in patients with wrist fractures? RC Trial. J Bone Joint Surg Am. 2007.
6. Jupiter JB, et al. Operative treatment of volar intra-articular fractures of the distal end of the radius. J Bone Joint Surg Am. 1996.
7. McQueen MM, et al. Redisplacement of distal radial fractures. J Bone Joint Surg Br. 1996.
8. Knirk JL, Jupiter JB. Intra-articular fractures of the distal end of the radius in young adults. J Bone Joint Surg Am. 1986. (Est. 2mm step off rule).
9. Lichtman DM, et al. AAOS Clinical Practice Guideline Summary: Treatment of Distal Radius Fractures. J Am Acad Orthop Surg. 2010.
10. Dolan LA, et al. The value of the 'watershed line' for volar plate placement. J Hand Surg Eur. 2012.

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13. Examination Focus

Common Exam Questions (FRCS/Boards)

1. What are the normal radiographic parameters? (Answer: H=11mm, I=22°, VT=11°).
2. Name the 4 eponymous fractures. (Answer: Colles, Smith, Barton, Chauffeur).
3. What is the watershed line? (Answer: The most distal volar rim of the radius. Plates past this risk FPL rupture).
4. How do you treat an EPL rupture? (Answer: EIP to EPL tendon transfer. Repair is not possible due to fraying).
5. Summarize DRAFFT Trial. (Answer: VLP vs K-wires showed no functional difference at 1 year for dorsally displaced fractures).

Viva "Buzzwords"

• "Watershed Line"
• "Volar Tilt"
• "Lafontaine Criteria"
• "Dinner Fork Deformity"
• "EIP Transfer"
• "Column Theory"

Common Pitfalls

• Plating past the watershed: Causes FPL rupture.
• Missing a Scaphoid fracture: Always check the scaphoid in wrist trauma.
• Missing Acute CTS: Must document Median Nerve status pre and post reduction.
• Assuming VLP is always better: In elderly, it adds risk with marginal functional gain (Arora/DRAFFT).