Safety of Rigid Intramedullary Nailing in Skeletally Immature Tibia Fractures—Risk of Growth Disturbance is Not Zero

Background: Rigid intramedullary nail (RIMN) fixation is the standard treatment for tibial shaft fractures in adult patients. Recently, this technique has gained favor for usage in skeletally immature patients despite the required violation of the proximal tibial physis. The goal of this paper was to determine whether growth disturbance with resultant deformity could occur after RIMN treatment in patients with open physes. Methods: A retrospective radiographic review was performed of all patients undergoing RIMN placement for acute tibia fractures at 3 level I Pediatric Trauma Centers between January 2012 and June 2022. Patients with an open proximal tibial physis and radiographic follow-up of at least 6 months were included. Intraoperative radiographs were analyzed to determine the immediate postoperative medial proximal tibial angle (MPTA) and posterior proximal tibial angle (PPTA), as well as the skeletal bone age utilizing the Abbreviated Modified Fels Knee System. The final radiographs were assessed for changes in the MPTA and PPTA. Results: A total of 43 patients with an average chronological age of 14.5±1.3 years and skeletal age of 14.3±1.0 years met the inclusion criteria. There were a total of 37 males and 6 females with an average follow-up of 18.3±12.7 months. The average change in the MPTA was 1.0 ± 0.9 degrees ( P =0.566) with no patients having a change >3 degrees. The average change in the PPTA was a 2.3 ± 3.8 degrees ( P =0.007). Two patients progressed to a recurvatum deformity with 99 and 104 degrees of PPTA. With these 2 patients excluded, the average change in slope remained significant at 1.5 ± 1.6 degrees ( P =0.019). Conclusion: The use of RIMN in skeletally immature adolescents can lead to a statistically significant, but most likely clinically insignificant change in the posterior slope. Yet, cases of recurvatum deformity can occur in the setting of this procedure. Though our series confirms RIMN are generally safe in treating tibial shaft fractures in skeletally immature adolescents, 2 cases demonstrate that a true risk of a subsequent sagittal deformity does exist. Level of Evidence: Level IV—retrospective case series.