Immobilization after pinning of supracondylar distal humerus fractures in children: Use of the a-frame cast

Background: Circumferential casts can contribute to elevated compartment pressures in the setting of acute swelling. We have developed a novel casting method (A-frame cast) that allows cast placement while leaving the antecubital fossa free of casting material. The purpose of this study was to evaluate the safety, efficacy, and complications associated with acute placement of this definitive cast after closed reduction percutaneous pinning (CRPP) of acute supracondylar distal humerus fractures. Methods: A retrospective medical record reviewed 436 patients treated with CRPP of supracondylar fractures by 3 surgeons who routinely used an A-frame cast over a 12-year period. All complications or the need for cast modification were noted. Patients with open reduction, ipsilateral fractures, or patients lost to follow-up were excluded. Results: There were 387 patients who met inclusion criteria, including 204 type 2 fractures and 183 type 3 fractures. Forty-three patients had preoperative nerve palsy and 1 had preoperative vascular injury. Of these 387 patients, 369 (95.3%) had an uneventful postoperative course. Nineteen patients (4.9%) required either cast splitting (15) or strict elevation (4) secondary to pain and swelling. Seven of these 19 patients had preoperative nerve palsy and 1 had preoperative vascular injury. The average time from procedure to cast splitting was 17.6 hours. No patients lost their reduction or required a second surgical procedure related to a complication from casting. Conclusions: An "A-frame" cast provides sturdy immobilization without increased risk of compartment syndrome after CRPP of supracondylar fractures in the pediatric population. Consideration should be given to splitting the cast prophylactically in patients with preoperative neurological or vascular deficits. Level of Evidence: IV-Case Series.