SLR - April 2014 - Matthew Wagoner
Reference: Toussaint RJ, Lin D, Ehrlichman LK, Ellington K, Stasser N, Kwon JY. Peroneal Tendon Displacement Accompanying Intra-Articular Calcaneal Fractures. JBJS. 2014 Feb; 96(4):310-315
Scientific Literature Review
Reviewed By: Matthew Wagoner, DPM
Residency Program: Temple University Hospital
Podiatric Relevance: The calcaneus is the most frequently fractured tarsal bone and is associated with approximately 10-15 percent of the patients presenting with bilateral involvement, other lower extremity fractures, or fractures of the lumbosacral spine. Both operative and non-operative treatments of calcaneal fractures are prone to an extensive list of complications. It is important to recognize that the injury may not be confined to osseous structures and that the soft tissue structures should be adequately evaluated for any potential injury. Peroneal tendon subluxation or dislocation accompanying intra-articular calcaneal fractures are often missed and therefore not treated. The purpose of this study was to determine the prevalence of peroneal tendon displacement accompanying intra-articular calcaneal fractures, determine the association of tendon displacement with fracture classifications, determine the association of tendon displacement with heel width, and lastly to determine the rate of missed diagnosis of the tendon displacement on radiographs and CT scans and the resulting treatment rate.
Methods: Following approval from the institutional review board, imaging studies of calcaneal fractures were retrospectively reviewed. Studies from three institutions over a five-year period from June 2006 to June 2011 were identified. Those studies that were excluded included those in which CT scans were not available (forty-six), extra-articular fractures (ninety-seven), skeletally immature patients (thirteen), and one case that was a result of a gunshot wound. A total of 421 cases of intra-articular calcaneal fractures which radiographs and CT scans were available were evaluated. On CT scan, peroneal tendon displacement was evaluated on both the axial and coronal images. On the axial CT scan, the peroneal tendons reside in the triangle formed by the distal aspect of the fibula, superficial peroneal retinaculum, and calcaneofibular ligament. On the coronal image, the common peroneal tendon sheath should lie within the fibular groove. Radiographs were evaluated to identify the “fleck sign,” which represents the avulsion of the fibular cortex at the attachment of the superior peroneal retinaculum. The maximal heel width was measured on the transverse CT images. Radiology reports were reviewed to determine if the radiologists identified peroneal tendon displacement. Medical and operative notes were reviewed to determine the cases that involved peroneal tendon displacement which subsequently underwent operative treatment and if the surgeon treated the displaced peroneal tendons during surgery.
Results: Of the 421 intra-articular fractures, 321 were classified as joint-depression, and 100 as tongue-type according to the Essex-Lopresti classification. Forty-three were Sanders Type I, 169 Type II, 138 Type III, and 60 Type IV. Peroneal tendon displacement was evident in 118 (28 percent), of cases. The displacement was identified in radiology reports in 12 cases (2.9 percent) of the study population. The fleck sign was noted in forty-four (10.5 percent) of cases and found to have a sensitivity of 0.31, and specificity of 0.98 with a positive predictive value of 0.84. Sixty-five (55.1 percent) of the intra-articular fractures with peroneal tendon displacement had undergone internal fixation, and the peroneal tendons were surgically treated at the time of operation in seven (10.8 percent) of cases. Treatment of the peroneal tendons occurred more frequently if the radiologist had already identified the tendon displacement. The mean heel width on CT scans was significantly greater in cases with peroneal tendon displacement than in cases without displacement. Thirty-one percent of joint-depression fractures had accompanying peroneal tendon displacement compared with nineteen percent of tongue-type fractures. Based on the Sanders classification, as the fracture was more severe, the risk of peroneal tendon displacement increased.
- Conclusion: This study showed a 28 percent prevalence of subluxation or dislocation of the peroneal tendons in association of intra-articular calcaneal fractures. While the clinical significance of the failure to recognize peroneal displacement is unknown, it is known that tendon injury alone can be debilitating. It is important to recognize other injuries associated with calcaneal fractures, outside of the immediate osseous injuries. Radiographic and CT scan can be utilized to help assess peroneal tendon displacement and should be reviewed to assess soft tissue injury in conjunction with osseous injury.