Objective: Despite their frequent occurrence, there is little clinical or biomechanical data associating the status of the fibula with any injury pattern of the tibial plafond. Similarly, the integrity of the fibula is not assessed in the commonly used tibial pilon fracture classification schemes. The purpose of this study was to determine whether there is a difference in the radiographic severity of tibial pilon injuries with fibular fractures compared with those without fibular fractures by using a rank-order method.
Design: Case-control, radiographic review.
Setting: Urban level-1, university trauma center.
Patients: During a 36-month period, 20 consecutive tibial pilon injuries without associated fibular fractures were retrospectively identified by using a prospectively gathered trauma database (group 1). During the same time period, an additional 197 tibial pilon injuries with fibula fractures were identified and classified according to the AO/OTA System. This included 48 AO/OTA 43B-type (24.4%) and 149 AO/OTA 43C-type (75.6%) fractures. From this larger group of patients, an age- (+/-5 years) and gender- matched cohort of 20 tibial pilon injuries with fibular fractures were randomly selected electronically (group 2).
Intervention: Digital concealment of the fibula on the anteroposterior and lateral injury radiographs.
Main outcome measure: Before definitive fixation, 3 orthopaedic traumatologists independently ranked the digitized anteroposterior and lateral radiographs of all 40 patients according to severity with 40 representing the most severe injury.
Results: Interobserver agreement between the 3 evaluators showed a significant positive association (Kendall's concordance coefficient = 0.87; P = 0.0001). The overall mean rank score for tibial pilon injuries with fibula fractures was 24.4, whereas those without fibula fractures was 16.7 (t test = 0.02). When evaluated within the AO/OTA classification system, the mean rank score for C-type tibial pilon fracture patterns was 10.3 in group 1 and 8.7 in group 2 (P = 0.5). AO/OTA C-type tibial pilon fracture patterns were observed more commonly in group 2 than in group 1 (P = 0.006).
Conclusions: This study demonstrates that, overall, tibial pilon injuries with fibular fractures were statistically ranked as more radiographically severe than those without fibular fractures. Fibular fractures are more commonly associated with C-type injuries than B-type injuries. There was no difference in severity in C-type injuries with or without fibular fractures; however, C-type injuries were ranked, as a group, significantly more radiographically severe than B-type injuries.