SLR - December 2023 - Londono
Title: Computed Tomography Analysis of Distal Tibia Physeal Fracture Patterns: A Classification and Technique for Optimizing Screw TrajectoryReference: Sheth M, Kitziger R, Bindner C, Rosenfeld SB. Computed Tomography Analysis of Distal Tibia Physeal Fracture Patterns: A Classification and Technique for Optimizing Screw Trajectory. J Pediatr Orthop. 2023 Nov-Dec 01;43(10):598-602. doi: 10.1097/BPO.0000000000002498. Epub 2023 Aug 29. PMID: 37642467.
Level of Evidence: Diagnostic, Level III
Reviewed By: Susana Londono, DPM, MBA
Residency Program: John Peter Smith, Fort Worth, TX
Podiatric Relevance: Transitional fractures, also referred to as “Tillaux” or “triplane” fractures, occur in the anterolateral distal tibia and involve the physis and ankle joint. These fractures often require operative management in an attempt to achieve anatomic reduction and decrease the risk of post-traumatic arthritis. Accurate screw placement and anatomic reduction is crucial to adolescent transitional fractures as residual displacement of greater than 2.5 mm after treatment can lead to inferior functional outcomes. Through retrospective radiographic analysis of CT scans, this study identifies three different types of fracture patterns and offers guidance for reproducible screw placement and stable fracture reduction.
Methods: The authors of this study performed a retrospective analysis on adolescent patients aged 11-17 with Tillaux or triplane fractures. They measured the angle created by the plane of the main fracture line from the incisura as well as the width ratio of the fracture fragment and the anterior distal tibia in the mortise plane. These measurements were collected using an axial CT scan slice caudal to the level of the physeal scar. This angle and ratio were then added to a scatter plot and fracture patterns were identified using a cluster analysis.
Results: Of the 69 patients that met the inclusion criteria, 32 patients had Tillaux fractures (46.4%) and 37 patients (53.6%) had triplane fractures. The cluster analysis identified three different clusters, indicating three distinct fracture patterns. Mean patient age was 15.9 years. There was no difference between the patient's mean age and fracture pattern. Differences were instead noted secondary to the maturity of the distal tibial physis as well as to the mechanism of injury. A Type 1 fracture pattern, for instance, is the smallest and most anterolateral and thus likely the most skeletally mature when compared to the other types. Type 1 (n=16) had a mean of 24.5 degrees away from the incisura and a mean distance of 21.1% from the tibiofibular joint. For Type 2 (n=20), the mean angle was 58.6 degrees and the mean distance was 48.7%. For Type 3 (n= 33), the mean angle was 88.6 degrees and the mean distance was 49.1%.
Conclusions: This study is the first to identify fracture patterns with consistent fragment sizes and fracture planes as they occur in Tillaux or triplane pediatric fractures. Identification of fracture patterns of articular injuries can better inform surgeons on surgical approaches and reduction techniques to achieve reproducible satisfactory results. The authors offer a simple equation which can be utilized in pre-operative planning to guide operative technique and assist in screw placement under intraoperative fluoroscopy. With this information, foot and ankle surgeons can optimize screw start point and trajectory in the axial plane to improve outcomes for pediatric patients and diminish the long-term effects of such injuries.