Overview
Closed reduction and percutaneous pinning provides reliable stabilization for displaced pediatric supracondylar humeral fractures while avoiding the need to maintain reduction in a tightly flexed cast. The priorities are a well-perfused hand, safe alignment, stable fixation and avoidance of an iatrogenic ulnar nerve injury. This guide principally addresses extension-type injuries; flexion-type and multidirectionally unstable fractures require modified reduction strategies (Tachdjian, Chapter 29).
Assessment and Urgency
Record skin condition, swelling and any anterior puckering before manipulation. A metaphyseal spike may have buttonholed through brachialis and trapped soft tissues.
Document radial pulse, capillary refill, hand temperature and color, together with median/anterior interosseous, radial and ulnar nerve function as cooperation permits. Repeat the examination after splinting and reduction.
Look for ipsilateral forearm or wrist injury. A palpable pulse does not exclude evolving compartment syndrome.
Increasing analgesic requirements and anxiety are important warning signs in children. Pain on passive finger extension may also occur; late pallor, paralysis and sensory loss should not be awaited.
Open injury, threatened skin, severe swelling or an abnormal neurovascular examination warrants emergency treatment. A comfortably perfused limb with intact skin and a normal examination can be managed on an urgent schedule with observation, as described in the source.
(Tachdjian, Chapter 29.)
Imaging and Indications
Finding | Implication |
|---|---|
Gartland II with coronal malalignment or unstable medial column | Reduction and fixation are favored because a cast may not control varus or valgus collapse. |
Gartland III | Completely displaced fracture, usually treated with reduction and percutaneous pins. |
Gartland IV | Instability in flexion and extension, often recognized during surgery; do not rely on a periosteal hinge. |
Varus, rotation or medial column collapse | Requires careful correction; distal humeral varus has limited remodeling potential. |
Anterior humeral line and capitellum | Assess sagittal reduction on a true lateral view, accounting for age-related variation. |
Obtain appropriate AP and lateral views of the distal humerus. Assess column alignment, translation and Baumann's angle using a consistent convention; positioning changes can alter measured angles. Selected type IIA injuries without coronal deformity may be managed by reduction and casting, but require surveillance for loss of position (Tachdjian, Chapter 29).
Positioning and Setup
Under general anesthesia, position the child at the table edge with the arm on a radiolucent support, allowing AP, lateral and oblique fluoroscopy.
Arrange the team so an assistant can maintain reduction while pins are inserted.
Prepare smooth K-wires appropriate to the child's size, pin protection, a splint and equipment for open reduction if necessary.
Plan to move the image intensifier rather than repeatedly rotate an extremely unstable fracture to obtain views.
(Tachdjian, Chapter 29.)
Surgical Technique
Closed Reduction of an Extension-Type Fracture
If anterior puckering is present, gently free the interposed muscle and skin using the milking maneuver described in the source before attempting reduction.
Apply steady longitudinal traction with countertraction and the elbow extended. Restore length, then correct coronal translation and varus-valgus deformity.
Maintain traction while directing the proximal fragment posteriorly and the olecranon/distal fragment anteriorly.
Flex the elbow in a controlled manner. Pronation can help stabilize a posteromedially displaced fracture; supination may assist a posterolaterally displaced pattern, depending on the remaining hinge.
Confirm reduction fluoroscopically. Do not force an unstable fracture into hyperflexion if this produces coronal malalignment; maintain the position that preserves reduction and perfusion.
Avoid repeated vigorous manipulations. If adequate safe reduction cannot be obtained, proceed to an appropriate open approach rather than increasing soft-tissue injury.
(Tachdjian, Chapter 29, Fig. 29.42.)
Lateral-Entry Pin Fixation
Maintain reduction and insert at least two lateral-entry pins, confirming their paths in orthogonal planes.
Ensure that each pin crosses the fracture, engages the proximal fragment and achieves bicortical purchase.
Maximize separation at the fracture site and capture both columns. Pins clustered at one point or with marginal proximal purchase do not provide reliable control.
Add a third lateral pin if stability is insufficient. The Tachdjian authors commonly use two lateral pins for type II and three for type III injuries.
Extend the elbow after fixation and assess alignment and pin placement on orthogonal views. Confirm that the construct maintains reduction during the necessary assessment.
(Tachdjian, Chapter 29.)
When a Medial Pin Is Needed
A medial-entry pin may be necessary for persistent instability or a proximal/oblique pattern that cannot be controlled with lateral pins. Protect the ulnar nerve directly, reduce elbow flexion and use a small incision with blunt identification of the bony entry point when swelling obscures landmarks. The source advises less than 80 degrees of flexion for medial pin placement and avoidance of excessive flexion afterward. A medial pin should not be inserted blindly into a swollen, hyperflexed elbow (Tachdjian, Chapter 29).
Final Checks and Immobilization
Confirm acceptable coronal and sagittal alignment, pin spread and bicortical purchase.
Reassess pulse and hand perfusion after reduction, fixation and application of the dressing.
Bend and cut pins with enough length for later removal, and protect the skin around the exposed pins.
Use a posterior splint or widely split cast that accommodates swelling. The source describes approximately 60–85 degrees of flexion, with particular restraint when a medial pin is present.
(Tachdjian, Chapter 29.)
Vascular and Neurologic Monitoring
A persistently pale or cool hand requires urgent reassessment and vascular exploration when indicated. A pink but pulseless hand is a separate problem: the source describes Doppler-guided assessment and close inpatient observation after reduction when perfusion is adequate. Absence of a Doppler signal or deterioration of temperature, color or perfusion changes the plan. A viable hand does not justify discharge without serial assessment; the authors describe observation for 24–48 hours in this setting (Tachdjian, Chapter 29).
New ulnar symptoms with a medial pin require prompt assessment of elbow position and the pin. The Tachdjian authors recommend removing the medial pin when symptoms persist despite appropriate positioning (Tachdjian, Chapter 29).
Postoperative Care
Educate the family about elevation, swelling, cast tightness and increasing pain. The source commonly reassesses at 7–10 days with radiographs, then repeats assessment around 3 weeks for pin and immobilization removal when healing allows. Motion returns gradually; avoid forced manipulation. Follow-up at approximately 7–10 weeks evaluates alignment, motion and readiness to resume activities. These are the source's typical intervals and must be adjusted for fracture stability and healing (Tachdjian, Chapter 29).
Complications
Loss of reduction and cubitus varus, usually related to inadequate reduction or fixation.
Pin-site inflammation or infection and, rarely, deep infection.
Iatrogenic ulnar nerve injury with medial pinning.
Vascular compromise, compartment syndrome and injury-related nerve palsy.
Temporary stiffness; persistent deformity or instability can have later consequences.
(Tachdjian, Chapter 29.)
References
Herring JA, ed. Tachdjian's Pediatric Orthopaedics: From the Texas Scottish Rite Hospital for Children. 6th ed. Elsevier; 2022. Chapter 29, Upper Extremity Injuries, supracondylar humeral fractures, pp. 1192–1212; closed reduction and pin fixation, pp. 1201–1207.