J Korean Fract Soc.  2022 Jul;35(3):103-108. 10.12671/jkfs.2022.35.3.103.

Assessment of Noncontiguous Posterior Malleolar Fractures in Distal One-Third Tibia Shaft Fractures with Proximal Fibula Fractures

• Kim DG
• Kwack BH

• KMID: 2532157
• DOI: http://doi.org/10.12671/jkfs.2022.35.3.103

Abstract

Purpose
Posterior malleolar fractures after intramedullary nail surgery rarely occur in distal tibia shaft fractures. The importance of preoperative ankle evaluation in preventing these fractures is also common knowledge. There are no studies in the literature on posterior malleolar fractures in distal onethird tibia shaft fractures except for distal metaphyseal tibia fractures to the best of our knowledge. The purpose of this study was to evaluate the incidence and radiological features of posterior malleolar fractures in distal one-third tibia shaft fractures with proximal fibula fractures.
Materials and Methods
Thirty-one patients diagnosed with distal one-third tibia shaft fractures with proximal fibula fractures from January 2016 to May 2021 were retrospectively reviewed. With the aid of plain radiographs and computed tomography (CT) scans, the fracture patterns of the tibia and fibula were classified according to the AO Foundation/Orthopedic Trauma Association (AO/OTA) classification, and posterior malleolar fractures were identified. The fracture pattern was classified according to the Haraguchi classification, and the angle between the bimalleolar axis and the posterior malleolar fracture line was measured when there was a posterior malleolar fracture.
Results
Out of the 31 distal one-third tibia shaft fractures with proximal fibula fractures, 16 cases (51.6%) had noncontiguous posterior malleolar fractures that were confirmed on a CT scan, while 3 cases (18.8%) were visible on initial plain radiographs. There was no statistically significant variation seen in the presence of a posterior malleolar fracture in the tibia (p=0.15) and fibula (p=0.87) fractures. According to the Haraguchi classification, there were 15 posterolateral-oblique fractures (Type I) and 1 medial-extension fracture (Type II), and the mean angle was 24.5°.
Conclusion
Noncontiguous posterior malleolar fractures occurred in approximately half of the distal one-third tibia shaft fractures with proximal fibula fractures, and a CT scan was considered necessary to diagnose posterior malleolar fractures before surgery

Keyword

Bimalleolar axis; Fibula fracture; Intramedullary nail surgery; Plain radiographs; Posterior malleolar fracture; Tibia fracture