K. I. Reddy1, J. Schultz2, L. Wollenman4, A. Rees5, S. Moore-Lotridge2,3, C. Louer2,3, N. Lempert2,3, J. Schoenecker2,3 2Vanderbilt University Medical Center, Department Of Orthopaedics, Nashville, TN, USA 3Vanderbilt University Medical Center, Division Of Pediatric Orthopaedics, Monroe Carell Jr. Children’s Hospital, Nashville, TN, USA 4Vanderbilt University Medical Center, Department Of Emergency Medicine, Nashville, TN, USA 1University Of Texas Health Science Center At Houston, Medical School, Houston, TX, USA 5Atrium Health, Department Of Orthopaedics, Charlotte, NC, USA
Introduction: Supracondylar humerus fractures (SCHF) are the most common elbow fracture in the pediatric population. Surgical treatment of these fractures involves first reducing the fracture (typically a closed reduction) and then pins are placed percutaneously across the fracture site to maintain the reduction. Prior literature has long suggested that Gartland Type 3 SCHF fixed with a two-pin construct have more post-operative complications such as loss of fixation than those fixed with three pins, but this comparison has not been extensively studied. The purpose of this study was to compare and analyze the post-operative outcomes of pediatric Type 3 SCHF patients treated with 2 pin constructs vs. 3 pin constructs.
Methods: We performed a retrospective cohort study of 884 pediatric Type 3 SCHF from a single tertiary teaching hospital (2007- 2017). Patients were divided into 2 groups: patients receiving 2 pins vs. patients receiving 3 pins intraoperatively. Post-operative data including loss of reduction, loss of fixation, pin tract infection, delayed union, malunion, deep infection, AVN, iatrogenic nerve injury, reoperations, and surgical duration data were analyzed to compare incidence between the 2 cohorts.
Results: A total of 884 subjects were included with 373(42.2%) having been treated with 2 pins and 511(57.8%) treated with 3 pins. Pre-operative demographics were similar between groups, as were pre-operative injury mechanisms. However, the rate of open fracture(p= 0.012) and neurovascular injury(p<0.001) was higher in the 3 pin cohort. Patients treated surgically with 2 pins showed no difference in loss of mechanical stability categories(p > 0.05) than those treated with 3 pins. The 3 pins cohort also had a higher percentage of patients incur pin tract infections (2pins:2.68%, 3pins:2.74%), iatrogenic nerve injuries (2pins:0%, 3pins:0.39%), and reoperations (2pins:1.07%, 3pins:2.54%), but these differences did not reach statistical significance. Additionally, there was a significant increase in the OR time needed to place 3 pins in the patient, compared to only 2 pins(p<0.001).
Conclusion: In the largest institutional cohort to date on pediatric elbow fractures, we saw that Type 3 SCHF treated with only 2 pins did not lose mechanical stability more frequently than those treated with 3 pins. These results suggest that if mechanical stability is achieved after the insertion of 2 pins, a 3rd pin is not required to mitigate a loss of fixation post-operatively. This challenges the often-stated dogma which has been taught to trainees (i.e. 2 pins for Type 2’s and 3 pins for Type 3’s) and this information can help optimize care by limiting the use of superfluous pins in these operations going forward.
