Courtesy: Michael Taunton MD
Mayo Clinic
USA

Supracondylar Fracture of the Humerus: Operative Technique (Closed Reduction and Percutaneous Pinning)

Preoperative Setup

• Position the patient near the edge of the operating table.
• Position the C arm below the table.
• Place the fluoroscopy monitor directly opposite the surgeon.
• Use the C arm surface as the working platform.
• Secure the patient’s head to prevent movement during traction.
• Use padding or towels to stabilize the body.

Initial Step

• Attempt closed reduction before skin preparation and draping.
• Confirm that closed reduction is achievable.
• Ensure adequate fluoroscopic visualization.
• Plan open reduction if satisfactory reduction cannot be achieved.

Closed Reduction Technique

Coronal plane correction

• Correct medial and lateral displacement first.
• Grasp the arm firmly.
• Use the thumb to manipulate the distal fragment into alignment.

Sagittal plane correction

• Begin with the elbow flexed approximately 30 degrees.
• Place the thumbs over the posterior aspect of the medial and lateral columns.
• Push the distal fragment anteriorly and distally.
• Hyperflex the elbow to complete the reduction.

Assessment of reduction

• Confirm medial and lateral column alignment on the anteroposterior view.
• Ensure the anterior humeral line passes through the capitellum on the lateral view.

Draping

• Perform standard extremity draping.
• Maintain the C arm within the sterile field without repositioning.

Percutaneous Pin Fixation

Pin configuration

• Two divergent lateral pins.
• Two lateral pins with one medial pin for maximum stability.

Medial Pin Technique

• Identify the medial epicondyle.
• Make a small incision over the medial epicondyle.
• Use a mosquito clamp to palpate the epicondyle.
• Retract and protect the ulnar nerve.
• Insert the K wire from posterior to anterior.

Lateral Pin Technique

• Insert two divergent lateral K wires.
• Engage the opposite cortex with both pins.
• Place the first pin in a more transverse direction.
• Insert the second pin slightly posterior to the first.

Stability Assessment

• Confirm that all pins cross the fracture site.
• Ensure each pin engages the far cortex.
• Verify satisfactory alignment on anteroposterior and lateral fluoroscopic views.

Pin Management

• Bend the exposed ends of the K wires approximately 90 degrees.
• Leave 7 to 10 mm of the pin outside the skin.
• Apply protective pin caps.
• Place foam padding around the pins to prevent skin irritation.

Cast Application

• Apply an above elbow cast.
• Maintain the elbow at approximately 80 to 90 degrees of flexion.
• Avoid excessive elbow flexion.
• Provide adequate padding.

Cast molding

• Flatten the posterior aspect of the humerus to prevent extension redisplacement.
• Apply anterior molding around the condyles.

Cast Modification

• Bivalve the cast to accommodate postoperative swelling.
• Relieve pressure over the antecubital fossa.

Final Assessment

• Obtain final anteroposterior and lateral fluoroscopic images.
• Repeat a complete neurovascular examination.
• Apply the final dressing.

Surgical Pearls

• Always protect the ulnar nerve during medial pin insertion.
• Avoid elbow hyperflexion beyond 90 degrees to reduce the risk of brachial artery compression.
• Cross pinning with one medial and two lateral pins provides the greatest mechanical stability.
• Lateral only pinning reduces the risk of ulnar nerve injury but may provide slightly less rotational stability.
• Complete fracture reduction before definitive fixation.

Complications

• Ulnar nerve injury.
• Loss of fracture reduction.
• Compartment syndrome.
• Volkmann ischemic contracture.