Physeal Fractures of the Distal Tibia Predictive Factors of Premature Physeal Closure and Growth Arrest

Background: A retrospective review of 124 patients was undertaken to determine the incidence of physeal growth arrest (premature physeal closure [PPC]) after physeal fractures of the distal end of the tibia in children. We also sought to identify clinical predictors of PPC. Methods: We defined PPC as radiographic evidence of physeal closure as compared to the uninjured side in this patient population. We reviewed the charts of 124 pediatric patients with distal tibia physeal fractures. All patients were followed up until symmetric growth was noted (by Harris growth lines) for a minimum of 1 year or until physiologic closure of the growth plates had been documented radiographically. We calculated the overall incidence of PPC and the incidence by fracture type. Cox multivariate regression analysis was also performed for a number of clinical variables. Results: The mean follow-up was 57 weeks. Fifteen fractures (12.1%) were complicated by PPC. In our study, 67% of the PPC observed occurred in Salter-Harris II fractures, followed by 13% in Salter-Harris III, 13% in Salter Harris IV, and 7% in triplane fractures. We did not observe any physeal arrest in the Salter-Harris I or Tillaux fractures. Using a Cox multivariate regression analysis, we were able to demonstrate statistically significant correlations between mechanism of injury and PPC and between the amount of initial fracture displacement and the rate of PPC. There was a strong relationship between mechanism of injury and PPC. There were trends seen about residual displacement after reduction and the number of attempted reductions and the rate of PPC, but these correlations were not statistically significant. For each millimeter of initial displacement, there was a relative risk of 1.15 (P < 0.01). Conclusions: Recent articles have shown a much higher rate of PPC after distal tibia physeal fracture than what was observed in our cohort. The amount of initial fracture displacement and the mechanism of injury have a statistically significant predictive value in determining the likelihood of PPC development after distal tibia physeal fracture. Trends were seen regarding residual displacement and the number of fracture reductions but were not statistically significant in predicting the occurrence of a PPC.