Incidence and recognition of peroneal tendon dislocation associated with calcaneal fractures

- Incidence of peroneal tendon dislocation associated with calcaneal fractures is 24%.
- Diagnosis was missed at initial presentation in 53% of cases.
- A bony fleck sign was present in 14% of tendon dislocators.
- Likelihood of tendon dislocation rises with larger size of lateral malleolar swelling.
- Beware of tendons that relocate and peep around posterolateral fibular corner on CT.

BackgroundQuestions abound regarding natural history and medicolegal implications of untreated peroneal tendon dislocation (PTD) associated with calcaneal fractures.MethodsWe retrospectively analyzed CT scans and anteroposterior ankle radiographs of 79 consecutive calcaneal fractures presenting over 4 years at a single institution.ResultsNineteen patients (24%) had associated PTD, which was initially missed in 10 (53%). Bony fleck was present in 11 (13.75%). Soft tissue swelling at lateral malleolar level, present on radiographs of 18 tendon dislocators (95%), raises likelihood of PTD with increasing specificity the greater the swelling. In 6 patients, surgeons failed to identify on CT spontaneously relocated tendons that then peeped around the posterolateral fibula, a finding not appreciable on 3-dimensional volume-rendering.ConclusionsDespite a significant association of PTD with calcaneal fractures, it still passes unrecognized all too frequently. Anatomical fracture fixation does not guarantee stable tendon reposition. Further studies are required to elucidate functional outcome of untreated PTD.