SLR - October 2014 - Maureen Heurich

Peroneal Tendon Displacement Accompanying Intra-Articular Calcaneal Fractures

Reference: Toussaint RJ, Lin D, Ehrlichman LK, Ellington JK, Strasser N, Kwon JY. Peroneal Tendon Displacement Accompanying Intra-articular Calcaneal Fractures. (2014). The Journal of Bone and Joint Surgery, 96(4), 310-315.

Scientific Literature Review

Reviewed By: Maureen Heurich, DPM
Residency Program: Saint Vincent Charity Medical Center

Podiatric Relevance: The calcaneus is the most commonly fractured tarsal bone and is associated with myriad complications including infection, subtalar joint arthritis, malunion, chronic pain, ankle impingement, and peroneal tendinopathy. Peroneal tendon displacement or subluxation is often overlooked and therefore left untreated. Several studies have examined the relationship between intra-articular calcaneal fractures and peroneal tendon displacement; however this study expands on previous research by determining the prevalence of displacement with intra-articular fractures, the association of peroneal tendon displacement with fracture classifications, and the rate of missed diagnosis of subluxing peroneals on standard radiographs and computed tomography.

Methods: A retrospective review of all imaging studies of calcaneal fractures was performed over a five year period at three institutions. A total of 421 intra-articular calcaneal fracture cases were included in the study. Peroneal tendon displacement was determined by a previously published technique by Ho et al in the American Journal of Roentgenology as well as examining radiographs for an avulsion of the fibular cortex (“fleck sign”) at the superior peroneal retinaculum. Fractures were classified with the Sanders and Essex-Lopresti systems.

Results: Peroneal tendon displacement was identified in 28 percent of the cases on plain film or CT scan, however it was only correctly identified on radiology reports in 2.9 percent of the study population or 10.2 percent of the cases with diagnosed displacement. The presence of the fleck sign was highly suggestive of peroneal tendon displacement (p<0.001) and was identified in 10.5 percent of cases. Of patients who required ORIF (55.1 percent), a total of seven (10.8 percent) had surgically treated peroneal tendons. Repair of the subluxing peroneals was much more common if the radiologist correctly diagnosed the patient prior to surgery. Displacement of the peroneals was much more common in joint-depression fractures (31 percent) compared with tongue-type fractures (19 percent). Additionally, the rate of displacement increased with each additional level on the Sanders classification with 58 percent of cases having peroneal displacement in Sanders type IV fractures (p<0.002).

Conclusion: The prevalence of peroneal displacement was 28 percent in this group of 421 intra-articular calcaneal fractures. Despite this high prevalence, radiologists often missed the diagnosis of displacement. Given the fact that peroneal displacement may lead to chronic pain after repair of the calcaneal fracture, podiatric surgeons should be highly suspicious of this condition. Additionally signs of peroneal displacement are evident on CT and plain radiographs and may help guide treatment and surgical intervention.

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