Open Reduction and Pin Fixation of Pediatric Lateral Humeral Condylar Fractures.

BACKGROUND: Lateral condylar fractures of the humerus are the second most common elbow fracture seen in pediatrics, behind supracondylar humeral fractures. All practicing orthopaedic surgeons should be able to identify and treat these injuries appropriately, as the intra-articular and transphyseal nature of this fracture pattern contributes to the relatively high complication rate. Treatment has evolved with time as classification systems better characterize the different types of lateral condylar fractures, aiding in decision-making for management. This video article reviews the diagnostic findings and classification systems for lateral condylar fractures and then details the surgical technique for open reduction and internal fixation of displaced lateral condylar fractures.

DESCRIPTION: Position the patient supine with the arm extended on a hand table with a sterile tourniquet. Center the incision over the capitellum. Follow the rent in the fascia to the fracture. Open the capsule anteriorly to view across the joint, avoiding excess posterior dissection to protect the blood supply. Clear soft tissue from the anterior surface of the fracture fragment, which will allow visualization of the fragment without excessive posterior dissection. Using a long retractor anteriorly to maintain visualization of the articular surface, reduce the fracture with a valgus force. Insert 2 pins percutaneously posterior to the incision. One pin should be parallel to the joint surface; the other should diverge >45° and fixate the medial metaphysis. Confirm reduction by direct visualization as well as by anteroposterior, lateral, and internal oblique radiographs. Cut and bend the pins outside the skin and close the incision with absorbable suture. Apply a long-arm cast.

ALTERNATIVES: Nonoperative management is reserved for fractures with <2 mm of displacement. Closed reduction can be attempted for fractures with 2 to 4 mm of displacement. Screw fixation may be utilized in some cases.

RATIONALE: Management of fractures displaced 2 to 4 mm is controversial and surgeon-dependent. Although cast immobilization for these fractures has been reported historically as successful1 , close follow-up is required as these fractures can have late displacement. Many authors have a low threshold for operative intervention if close follow-up cannot be guaranteed or if there is concern for increasing displacement2 . Both closed reduction and percutaneous pinning with an arthrogram and open reduction with direct visualization and fixation are acceptable treatment methods3 . There is consensus that surgery is warranted for a displaced lateral condylar fracture with malrotation or articular incongruity. Although there is 1 report of percutaneous reduction and fixation in substantially displaced fractures4 , most surgeons perform open reduction with either pin or lag screw fixation for fractures displaced >4 mm. Although lag screw fixation is biomechanically superior5 and has higher union rates6,7 and lower infection rates8 , a second surgery is necessary for implant removal because of growth concerns9 .

EXPECTED OUTCOMES: Bone union and good clinical results can be obtained in children with a lateral condylar fracture10 . Lateral overgrowth in the form of a "lateral spur" and cubitus valgus are the most common residual deformities seen10 . Nonunion, osteonecrosis, fishtail deformity, and ongoing range of motion limitations are seen less commonly in lateral condylar fractures11-13 .

IMPORTANT TIPS: Reserve nonoperative management for minimally displaced fractures that can be followed closely.An arthrogram is required for closed reduction to ensure joint surface congruity.Avoid posterior dissection as it risks the blood supply to the distal fragment.Counsel parents that lateral overgrowth is to be expected and results in no functional limitations to the patient.