Anatomical Study Of Sites And Footprints Of Tibial Posterior Tendon Attachment

Background: The purpose of this study was to clarify variations in the tibialis posterior tendon (TPT) attachment site using a large sample and to quantify the contribution of each attachment site by examining the surface area of the attachment region.Methods: We examined 100 feet from 50 Japanese cadavers. The TPT of attachment to the the navicular bone (NB), medial cuneiform bone [1], and lateral cuneiform bone (LCB) was set as the main attachment site (Type I). Type II was defined as one extra attachment site in addition to those of Type I, meaning attachment to a total of four sites. Classification up to Type VII was seen according to the number of additional attachment sites. Furthermore, surface area was measured using a 3-dimensional scanner to make the foot sample three-dimensional. Surface area was then calculated using 3-dimensional software.Results: Attachment to the NB, MCB, and LCB was present in all specimens. Attachment to the intermediate cuneiform bone was seen in 25 feet (25%), and to the cuboid bone in 66%. Among 1st–5th metatarsal bones, 4th metatarsal bone was the most attached, at 95%. The TPT attachment to the NB, MCB, and LCB were comprising 75.1% of total attachment surface area. The ratio of the NB, MCB and LCB in each type was about 90% in Types II and III, and 70–80% in Types IV–VII.Conclusion: Attachment of the TPT to the NB, MCB, and LCB may thus contribute to stability of the foot arch.