Outcomes and Predictors of Popliteal Artery Injury in Pediatric Trauma

Background: Popliteal artery injury (PAI) is a rare occurrence in pediatric patients with significant consequences. Delays in diagnosis lead to severe complications such as lifelong disability and limb loss. We sought to identify outcomes and clinical predictors of PAI in the pediatric trauma population. Methods: The Pediatric Trauma Quality Improvement Program (2014-2016) was queried for patients <= 17 years old with PAI. Patient demographics and outcomes were characterized. A comparison of patients sustaining blunt versus penetrating PAI was performed. A multivariable logistic regression analysis was used to identify predictors of PAI. Results: From 119,132 patients, 58 (<0.1%) sustained a PAI with 74.1% from blunt trauma. Most of the patients were male (75.9%) with a median age of 15 and median Injury Severity Score of 9. A majority of the patients were treated with open repair (62.1%) in comparison to endovascular repair (10.3%) and nonoperative management (36.2%). The rates of open and endovascular repair and nonoperative management were similar between blunt and penetrating PAI patients (P = not significant). Concomitant injuries included popliteal vein injury (PVI) (12.1%), posterior tibial nerve injury (3.4%), peroneal nerve injury (3.4%), and closed fracture/dislocation of the femur (22.4%), patella (25.9%), and tibia/fibula (29.3%). Overall complications included compartment syndrome (8.6%), below-knee amputation (6.9%), and above-knee amputation (3.4%). The overall mortality was 3.4%. Patients with PAI secondary to penetrating trauma had a higher rate of concomitant PVI (26.7% vs. 7%, P = 0.04) and posterior tibial nerve injury (13.3% vs. 0%, P = 0.02) but a lower rate of closed fracture/dislocation of the patella (0% vs. 34.9%, P = 0.008) and tibia/fibula (0% vs. 39.5%, P = 0.004) compared to patients with PAI from blunt trauma. Predictors for PAI included PVI (odds ratio [OR] 296.57, confidence interval [CI] = 59.21-1,485.47, P < 0.001), closed patella fracture/dislocation (OR 50.0, CI = 24.22-103.23, P < 0.001), open femur fracture/dislocation (OR 9.05, CI = 3.56-22.99, P < 0.001), closed tibia/fibula fracture/dislocation (OR 7.44, CI = 3.81-14.55, P < 0.001), and open tibia/ fibula fracture/dislocation (OR 4.57, CI = 1.80-11.59, P < 0.001). PVI had the highest association with PAI in penetrating trauma (OR 84.62, CI = 13.22-541.70, P < 0.001) while closed patella fracture/dislocation had the highest association in blunt trauma (OR 52.01, CI = 24.50-110.31, P < 0.001). Conclusions: A higher index of suspicion should be present for PAI in pediatric trauma patients presenting with a closed patella fracture/dislocation after blunt trauma. PVI is most strongly associated with PAI in penetrating trauma. Prompt recognition of PAI is crucial as there is a greater than 10% amputation rate in the pediatric population.