Posterior tibial tendoscopy: Description of an accessory proximal portal and assessment of tendon vascularization lesion according to portal

Abstract

Posterior tibial tendoscopy was codified in 1997 by Van Dijck, who described a portal between 1.5 and 2cm proximally and distally to the tip of the medial malleolus. However, this approach does not allow proximal exploration of the posterior tibial tendon (PTT). We here describe an accessory portal 7cm proximal to the medial malleolus, enabling complete PTT exploration. Posterior tibial tendoscopy was performed on 12 cadaver specimens, mapping PTT exploration and vascularization. The accessory portal enabled the whole PTT to be explored, from the myotendinous junction to the entry into the retromalleolar groove. PTT observation quality was improved compared to using a submalleolar portal. Dissection confirmed systematic presence of a vincula on the posterior side of the tendon, connected to the flexor digitorum longus (FDL) tendon, containing collateral vessels of the posterior tibial artery. None of these elements were damaged by the tendoscopy as long and the scope and motorized instruments were not rotated on the posterior side of the supramalleolar part of the PTT. This accessory entry portal provides complete PTT exploration without the risk of neurovascular bundle lesion.