What is the step-by-step procedure for a posterior approach plating for a fracture of the supracondylar humerus?

Posterior Approach Plating for Supracondylar Humerus Fractures: Step-by-Step Procedure

The posterior approach with plating is the recommended surgical technique for adult supracondylar humerus fractures, providing optimal exposure for anatomical reduction and rigid fixation, allowing immediate postoperative movement for the best functional outcomes. 1

Preoperative Preparation

• Conduct appropriate imaging studies (X-rays in AP and lateral views)
• Position the patient in either:
  • Lateral decubitus position, or
  • Prone position with the affected arm supported on an arm board 1
• Prepare and drape the entire upper extremity to allow full manipulation

Surgical Procedure

Step 1: Incision and Exposure

• Make a straight posterior midline incision centered over the olecranon, extending proximally along the posterior aspect of the arm
• Deepen the incision through the subcutaneous tissue to expose the triceps mechanism

Step 2: Triceps Management

• Option A: Triceps-splitting approach
  • Split the triceps muscle and tendon in the midline
  • Reflect the muscle fibers laterally and medially to expose the posterior humerus
• Option B: Olecranon osteotomy approach (note: may lead to less good results) 2
  • Create a chevron-type osteotomy at the olecranon
  • Elevate the olecranon fragment with the attached triceps to expose the distal humerus

Step 3: Fracture Identification and Preparation

• Identify the fracture fragments
• Clear the fracture site of hematoma and debris
• Identify and protect the ulnar nerve, which is at risk during this procedure

Step 4: Fracture Reduction

• Anatomically reduce the fracture fragments
• Temporarily hold the reduction with K-wires

Step 5: Plate Application

• Select an appropriate anatomically contoured plate (typically a posterior or dual plate configuration)
• Apply the plate(s) to the posterior surface of the distal humerus
• Ensure proper plate positioning to avoid hardware prominence

Step 6: Fixation

• Secure the plate with screws proximally and distally to the fracture
• Confirm stable fixation and anatomical reduction
• Verify the alignment and stability under fluoroscopy

Step 7: Closure

• If olecranon osteotomy was performed, reattach the olecranon with tension band wiring or screws
• Repair the triceps mechanism meticulously if split
• Close the wound in layers
• Apply a sterile dressing and a posterior splint with the elbow in approximately 30° of flexion

Postoperative Management

• Begin early controlled mobilization as soon as pain allows to prevent stiffness 1
• Remove the posterior splint within 1-2 weeks
• Initiate physical therapy for range of motion exercises
• Progress to strengthening exercises as healing advances

Potential Complications and Prevention

• Ulnar nerve injury: Careful identification and protection during surgery
• Triceps weakness: Adequate repair of the triceps mechanism
• Elbow stiffness: Early mobilization
• Hardware prominence: Proper plate contouring and positioning
• Infection: Meticulous surgical technique 1

Important Considerations

• While closed reduction with percutaneous pinning is generally preferred for pediatric supracondylar fractures 3, open reduction and plating via posterior approach is often necessary for adult fractures to achieve anatomical reduction with rigid fixation 4
• Anatomical reduction with rigid fixation allowing immediate postoperative movement gives the least morbidity and best results in adult patients 4
• The triceps-splitting approach may provide better functional outcomes compared to olecranon osteotomy 2

This procedure requires meticulous attention to detail, particularly regarding nerve protection and anatomical reduction, to optimize functional outcomes and minimize complications.