Ankle injuries in distal tibial spiral shaft fractures: results from an institutional change in imaging protocol

Introduction: Posterior malleolus and other articular ankle injuries are known to concomitantly occur with tibial shaft fractures, especially spiral fractures of the distal one-third diaphysis. Due to our heightened awareness of this combined injury, our department instituted a new preoperative ankle imaging protocol for all distal one-third spiral tibia shaft fractures. The purpose of this study was to evaluate the effectiveness of an imaging protocol involving radiographs, CT and magnetic resonance imaging (MRI) in a distal one-third spiral tibia fracture cohort.

Materials and methods: All operatively treated patients with a spiral distal one-third tibial shaft fracture from February 2012 to March 2013 underwent a standardized ankle imaging protocol. Patients had preoperative orthogonal ankle radiographs as well as a CT scan of the tibia that included the ankle. All ankle imaging was scrutinized for evidence of an ankle injury. If no ankle fracture was identified, patients would then undergo an ankle MRI.

Results: Twenty-five patients met the inclusion and exclusion criteria for this study. Concomitant osseous ankle injuries were identified by radiograph and CT in 56 % (14/25) of cases. The remaining 44 % (11/25) of patients had no evidence of a combined injury by radiograph or CT and therefore underwent an MRI. Of the MRI cohort, 64 % (7/11) were found to have an occult ankle fracture. The overall incidence of a combined injury using our protocol was 84 % (21/25). Identification of an occult injury led to a change in management for all of these patients.

Conclusions: Concomitant ipsilateral ankle and distal one-third spiral tibial shaft fractures are more common than previously reported. Utilizing a new imaging protocol, we found that the incidence of this combined injury was 84 %. Recognition of the ankle fracture component in this tibial shaft cohort can be important as it may alter the surgical plan and postoperative management.