An anatomical and radiological study of the fascia cruris and paratenon of the Achilles tendon

BackgroundThe Achillon jig permits the placement of sutures deep to the fascia cruris and the paratenon through the substance of the ruptured tendon, permitting a safe minimally invasive repair. Our experience has suggested that these two layers may not be as clearly delineated as first thought or may merge at an, as yet, undefined level.MethodsWe performed an anatomical and radiological (US and MRI) study of the layers of tissue superficial to the Achilles tendon in cadaveric specimens.ResultsThe mean distance for the confluence of the fascia cruris and paratenon from the postero-superior calcaneal tubercle (PSCT) was found to be 37.3 mm (range 17–58 mm). Ultrasound examination was found to be less distinct than MRI scanning.ConclusionsWe recommend careful identification of the fascia cruris and paratenon and insertion of the central branches of the jig adjacent to the tendon substance when using this method for repair.