Prevalence and Predictors of Peroneal Tendon Instability Accompanying Calcaneal Fractures

Abstract

Background: We aimed to find the prevalence of peroneal tendon instability (PTI) accompanying different types of calcaneal fractures and to determine predictors of PTI based on preoperative CT scanning. Methods: In a retrospective cross-sectional study, preoperative CT scans of 400 consecutive calcaneal fractures undergoing surgery were reviewed for comminuted fragments in the lateral gutter of the ankle, fractures at the tip of the lateral malleolus, dislocated peroneal tendons, excessive displacement of the lateral calcaneal wall, calcaneal fracture-dislocation, superior peroneal retinaculum (SPR) avulsion fracture (fleck sign), and shape of the retromalleolar groove. The correlation of these variables with intraoperative SPR stress test, defined as the diagnostic criteria for PTI in calcaneal fractures, was evaluated. Results: In total, 369 patients (mean age, 39 ± 13; range, 11-72 years), with 321 (87.0%) of them male, were included. Among all calcaneal fractures, 67 cases (16.7%) had associated PTI as confirmed intraoperatively by an SPR stress test. A statistically significant association was found between PTI in calcaneal fractures and comminuted fragments in the lateral gutter of the ankle ( P = .03), dislocated peroneal tendons ( P < .001), calcaneal fracture-dislocation ( P < .001), SPR avulsion fracture ( P < .001), and Sanders type IV of calcaneal fracture ( P = .02). There was no statistically significant relationship between PTI and the mechanism of injury ( P = .98), side of fracture ( P = .30), uni- or bilateral calcaneal fractures ( P = .27), a fracture at the tip of lateral malleolus ( P = .69), shape of the retromalleolar groove ( P = .78), or excessive displacement of the lateral calcaneal wall ( P = .06). The most specific CT finding to predict PTI accompanying calcaneal fractures was calcaneal fracture-dislocation (99.1%). Conclusion: Following calcaneal fracture fixation, PTI was confirmed with intraoperative SPR stress test in one-sixth of cases. With the exception of calcaneal fracture-dislocation, preoperative findings on CT scanning and calcaneal fracture pathoanatomy are insufficient to diagnose PTI accompanying calcaneal fractures. Level of Evidence: Level III, retrospective case control study.

Peroneal Tendon Instability in Calcaneus Fractures: A Commentary

“…Therefore, early diagnosis of peroneal instability is important to maximize recovery after treatment of the primary injury and reduce the need for secondary stabilization procedures. Vosoughi et al 10 have provided a large retrospective cohort to corroborate prior studies, suggesting a notable prevalence (16.7%) of peroneal tendon instability in the setting of calcaneus fracture. These higher-energy injuries already lead to significant functional limitations, 9 and it is important to identify any features possible to improve patient outcomes.…”

“…Like many high-energy bony injuries, a calcaneus fracture is more than just the “fracture.” In this issue of FAI , Vosoughi et al 10 provide a large-scale cross-sectional evaluation of peroneal tendon instability in the setting of displaced intra-articular calcaneal fractures. They compared preoperative imaging findings to intraoperative stress testing to quantify the prevalence of peroneal dislocation in one of the largest cohorts to investigate this issue.…”