What is the step-by-step procedure for treating a fracture of the supracondylar humerus using plating?

Step-by-Step Procedure for Supracondylar Humerus Fracture Plating

Open reduction and internal fixation with anatomical plating is the recommended surgical approach for treating supracondylar humerus fractures in adults, providing superior fixation and better anatomic restoration of the distal humerus. 1

Preoperative Planning

1. Imaging Assessment

   • Obtain AP and lateral radiographs of the elbow
   • CT scan with 3D reconstruction for complex fracture patterns
   • Assess fracture pattern, displacement, comminution, and articular involvement

2. Patient Positioning

   • Place patient in lateral decubitus or prone position
   • Alternatively, supine position with arm table extension
   • Position the affected arm with elbow flexed at 90 degrees

Surgical Approach

1. Anesthesia and Preparation

   • General anesthesia with muscle relaxation
   • Apply tourniquet to upper arm
   • Prepare and drape the entire upper extremity

2. Incision and Exposure

   • Posterior Approach (Most Common)

     • Make a midline posterior incision (15-20 cm)
     • Identify and protect the ulnar nerve
     • Elevate skin flaps to expose the triceps
     • Use a triceps-splitting or TRAP (triceps-reflecting anconeus pedicle) approach

   • Alternative: Anterior Approach

     • Consider for specific fracture patterns
     • Make an anterior median incision over the distal humerus 2
     • Protect neurovascular structures (median nerve, brachial artery)

3. Fracture Identification

   • Identify fracture fragments
   • Clear fracture hematoma and debris
   • Protect and identify any exposed nerves (particularly ulnar nerve)

Reduction and Fixation

1. Fracture Reduction

   • Perform anatomic reduction of articular fragments first
   • Use K-wires for provisional fixation
   • Restore the articular surface with anatomic precision
   • Verify reduction under direct visualization and with fluoroscopy

2. Plate Application

   • Parallel Plating Technique (Preferred)

     • Apply two plates in parallel configuration on medial and lateral columns
     • Position plates in sagittal plane for maximum stability 3
     • Ensure plates extend proximally beyond fracture line for adequate fixation

   • Plate Selection

     • Use pre-contoured anatomical locking plates designed for distal humerus
     • Anatomical plates provide superior fixation compared to standard plates 1

3. Screw Insertion Principles

   • Every screw in distal fragments should pass through a plate
   • Maximize number of screws in distal fragments
   • Each screw should be as long as possible
   • Create interdigitation of screws for fixed-angle stability
   • Ensure screws engage multiple fragments when possible 3

4. Compression and Stability

   • Apply compression at supracondylar level for both columns
   • Ensure rigid fixation to allow early mobilization
   • Verify stability of construct with gentle range of motion

Wound Closure and Postoperative Care

1. Final Assessment

   • Perform final fluoroscopic check of reduction and hardware position
   • Test elbow range of motion to ensure stability of fixation
   • Irrigate wound thoroughly

2. Closure

   • Close deep fascia with absorbable sutures
   • Close subcutaneous tissue and skin in layers
   • Apply sterile dressing and posterior splint in 90° flexion

3. Postoperative Protocol

   • Remove splint within 1-2 weeks
   • Begin early controlled range of motion exercises
   • Progress to active-assisted and active exercises as tolerated
   • Avoid heavy lifting for 3 months

Critical Technical Pearls

• Ulnar Nerve Management: Always identify and protect the ulnar nerve; consider formal transposition if at risk
• Plate Positioning: Plates must be strong enough to resist breaking or bending before union occurs 3
• Bone Quality Considerations: In osteoporotic bone, use locking plates and maximize screw purchase
• Comminution Management: Severe metaphyseal comminution may require supracondylar shortening 3

Potential Complications and Prevention

• Ulnar Neuropathy: Careful identification and protection of nerve during surgery
• Elbow Stiffness: Early mobilization with stable fixation
• Hardware Failure: Use of anatomical locking plates with proper screw placement
• Nonunion: Anatomic reduction with rigid fixation and early surgery provide best results 1

This surgical approach focuses on anatomic reduction, rigid fixation, and early mobilization to achieve optimal functional outcomes for patients with supracondylar humerus fractures.