Isolated Radius Fractures

AO/OTA Classification System

The AO/OTA classification for forearm fractures uses the code 22 (forearm bones):

• 22-A: Simple fractures (transverse or oblique)
  • A1: Ulna alone
  • A2: Radius alone (This topic)
  • A3: Both bones
• 22-B: Wedge fractures (butterfly fragment)
• 22-C: Multifragmentary (comminuted) fractures

Understanding the AO classification helps guide treatment: Type A fractures can achieve absolute stability with compression plating, while Type C fractures require bridge plating techniques.

Anatomic Location Classification

Fracture location determines deforming forces and surgical approach:

• Proximal Third: Supination deformity. Hardest to access (PIN risk). Requires careful nerve protection during exposure.
• Middle Third: Neutral deformity. Apex of bow. Most common location for isolated radius fractures.
• Distal Third: Pronation deformity. Galeazzi risk. Must always assess DRUJ stability.

The location-based classification is clinically useful for preoperative planning and understanding the deforming forces that must be overcome during reduction.

Decision Tree for Isolated Radius Fractures

Step 1: Assess Displacement

• Non-displaced (less than 2mm): Cast immobilization with weekly monitoring
• Displaced (greater than 2mm): Surgical fixation required

Step 2: Evaluate Fracture Pattern

• Simple (Transverse/Oblique): Compression plating for absolute stability
• Comminuted (Wedge/Multifragmentary): Bridge plating for relative stability

Step 3: Determine Surgical Approach

• Proximal 1/3: Dorsal (Thompson) or Volar (Henry) - both require PIN protection
• Middle/Distal 1/3: Volar (Henry) approach is preferred

Step 4: Address Special Considerations

• Open Fractures: Immediate antibiotics, I&D, and immediate plating if wound clean
• Segmental Fractures: High risk of compartment syndrome and nonunion - consider staged approach
• Bone Loss: Staged Masquelet technique may be required
• Pathological: Biopsy first, then fix - oncologic principles take precedence

The goal is anatomic reduction with stable fixation to allow early motion and prevent complications.

Indications for Conservative Treatment

Non-operative management is rarely appropriate for adult isolated radius fractures:

• Indication: Isolated, non-displaced (less than 2mm), rotatory neutral fractures. Very rare in adults. Better for pediatric patients.
• Cast Type: Long Arm Cast with appropriate forearm rotation based on fracture level
• Position:
  • Supination for proximal third fractures
  • Neutral for middle third fractures
  • Pronation for distal third fractures
• Follow-up: Weekly X-rays for 4 weeks to monitor for displacement
• Failure Rate: High (40-60% displacement rate in adults)
• Conversion: Low threshold to convert to ORIF if any displacement occurs

Most adult isolated radius fractures will displace and require surgical fixation. Conservative management should only be considered in very low-demand elderly patients with minimal displacement.

The Workhorse:

• Incision: Line from Biceps tendon to Radial Styloid.
• Superficial Interval: Between Brachioradialis (Radial N) and FCR (Median N). Deep Dissection (Step-by-Step):

1. Radial Recurrent Vessels: aka "Leash of Henry". These are a fan of vessels (arteries and veins) crossing the field from medial to lateral just distal to the elbow. They must be individually ligated or cauterized.
2. Supinator: Once the leash is cut, you can see the Supinator muscle fibers wrapping around the proximal radius.
3. Supination: Supinate the forearm fully. This moves the PIN (which runs IN the Supinator) laterally and away from your incision.
4. Incision: Incise the Supinator insertion on the anterior aspect of the radius down to bone.
5. Elevation: Elevate the muscle laterally. Do NOT retract vigorously. The PIN is protecting within the muscle belly.
6. Exposure: This reveals the proximal third of the radius.

Plate Application:

• Contouring: The radius is not straight. It has a proximal bend and a distal bow.
• LCDCP vs LCP: Compression plating is preferred for simple transverse fractures. LCP (Locking) is reserved for osteoporotic bone or comminution (bridge mode).
• Screw Density: Aim for 3 bicortical screws on each side of the fracture.
• Torque: Do not over-torque screws in the forearm, the bone is hard but narrow.

Implant Selection (Synthes LCP Small Fragment Set):

• Plate: 3.5mm LCP (Locking Compression Plate) is standard.
• Screws:
  • 3.5mm Cortical Screws (Gold): Use for compression or lagging. Drill bit 2.5mm.
  • 3.5mm Locking Screws (Green): Use for osteopenic bone or bridge plating. Drill bit 2.8mm.
• Length: 7-hole or 8-hole plate typified.
• Material: Stainless Steel (316L) or Titanium (Ti-6Al-4V). Stainless steel is stiffer and cheaper.

Reduction Maneuvers:

• Toggle: Insert a screw into one fragment, but leave it loose. Use the plate as a lever to toggle the reduction.
• Traction: Assistant provides traction (finger traps unnecessary for shaft, manual is fine).
• Rotation: Match the rotation of the fragments. Look at the interosseous border - it should be a sharp line. If it is dull or jagged, you are rotated.
• Clamps: Pointed reduction clamps (Weber) are useful but hard to place deeply. Verbal reduction (Traction, Rotate) is safer than aggressive clamping in the deep wound.

Top 5 Surgical Pearls:

• 1. Release the Brachioradialis tendon: If exposure is tight distally, partially releasing the BR tendon (distal release) allows much greater retraction.
• 2. Supinate for Proximal Exposure: You cannot see the proximal radius without full supination. If you can't supinate, release the pronator quadratus more distally or checking for block.
• 3. Plate the Tension Side: The volar surface is the tension side for the distal radius, but the radius is curved. The plate must be contoured to match the curve, otherwise tightening the screws will straighten the bone and lose the bow.
• 4. Use the correct screw length: Intra-articular screws in the DRUJ or PRUJ are disasterous. Shaft screws that are too long will irritate the dorsal tendons (EPL). Measure twice.
• 5. Don't strip the periosteum: Only strip what is under the plate. Preserve the soft tissue attachments elsewhere to maintain blood supply.

Always check the DRUJ one last time before leaving the theatre.

Thompson Approach for Proximal Third

The dorsal approach is useful for very proximal radius fractures where the Henry approach may be limited:

• Incision: Line from Lateral Epicondyle to Lister's Tubercle, following the interval between extensor compartments
• Interval: Between ECRB (Radial N) and EDC (PIN) - this is the internervous plane
• Danger: PIN is found emerging from Supinator at the distal border - must be identified and protected
• Exposure: Limited to proximal third of radius
• Plating: Apply plate dorsally. Harder to get soft tissue cover (thin skin over dorsal surface)
• Disadvantages:
  • Less soft tissue coverage
  • Risk of extensor tendon irritation
  • More difficult to extend distally

The Thompson approach is reserved for specific cases where proximal exposure is critical and the Henry approach cannot provide adequate visualization.

Principles of Forearm Fracture Fixation

Compression Plating (Absolute Stability):

• For simple transverse or short oblique fractures
• Over-bend the plate to compress the far cortex (eccentric compression)
• Achieves primary bone healing without callus

Lag Screw Technique:

• Interfragmentary screw through the plate or outside the plate for oblique fractures
• Creates interfragmentary compression
• Must be perpendicular to the fracture line

Screw Configuration:

• 3 bicortical screws (6 cortices) proximal and distal to the fracture minimum
• More screws may be needed for osteoporotic bone or comminution
• Locking screws for osteoporotic bone or bridge plating

Plate Selection:

• 3.5mm LCP plates are standard
• Length: 7-8 holes typical, longer for comminuted fractures
• Pre-contoured plates available but manual contouring often needed to match radial bow

Following these principles ensures stable fixation that allows early motion and prevents complications.

• Week 0-2 (Wound):
  • Splint: Posterior slab or removable splint.
  • Elevation: Critical to reduce swelling and compartment pressure.
  • Motion: Immediate active finger motion to prevent tendon adhesions and edema.
• Week 2-6 (ROM):
  • Sutures: Removal at 10-14 days.
  • Active Motion: Start Active elbow flexion/extension.
  • Rotation: Start Supination/Pronation. This is often the hardest to regain. Do it with elbow at 90 degrees (isolates forearm) and 0 degrees.
  • Restrictions: No heavy lifting (cup of coffee only).
• Week 6-12 (Strength):
  • X-ray: Check for calligraphy union.
  • Strengthening: Begin progressive resistance exercises if union is evident.
  • Work: Return to light duties.
• Month 3-6 (Return):
  • Sport: Contact sports allowed when cortical bridging is seen on 3 of 4 cortices.
  • Full Duty: Manual labor allowed.
• Specific Milestones:
  • Driving: allowed when out of splint and can grip wheel/turn comfortably (approx 6 weeks).
  • Typing: allowed immediately (fingers free).
  • Push-ups: Not allowed until 3 months (axial load).

• Rotation: Lost pronation is tolerated better than lost supination (shoulder abduction can compensate for pronation, but nothing compensates well for supination).
• Edema: Persistent edema leads to fibrosis of the IOM and stiffness. Aggressive early edema management is key.
• Scar: The Henry scar can be sensitive. Desensitization massage starts at 3 weeks.
• Proprioception: Use gyroscope ball or wobble board for wrist stability late in rehab.
• Occupational Therapy (OT):
  • Splinting: Dynamic splinting may be required if stiffness persists at 6 weeks (e.g., Turnbuckle splint for supination).
  • Heat/Cold: Contrast baths to maximize vascular flow and reduce swelling.
  • Functional Tasks: Practice turning doorknobs, using screwdrivers, pouring water.