Variations of the plantar tarsometatarsal ligaments.

This study investigated the morphological variations of the plantar tarsometatarsal ligaments of the foot by classifying them based on their ligamentous components. Fifty embalmed feet from 27 adult Korean cadavers were used. The plantar tarsometatarsal ligaments comprised nine components (medial cuneiform-first metatarsal, pCn1-M1; medial cuneiform-second metatarsal, pCn1-M2; medial cuneiform-second and third metatarsals, pCn1-M2,3; median cuneiform-second metatarsal, pCn2-M2; lateral cuneiform-third metatarsal, pCn3-M3; lateral cuneiform-fourth metatarsal, pCn3-M4; lateral cuneiform-third and fourth metatarsals, pCn3-M3,4; cuboid-fourth metatarsal, pCb-M4; and cuboid-fifth metatarsal, pCb-M5). pCn1-M2 was newly observed in the present study. The number of the bands composing the ligament was one in the pCn1-M2, pCn2-M2, pCn3-M3, and pCn3-M4 components, and one or two in the pCn1-M1, pCn1-M2,3, pCn3-M3,4, pCb-M4, and pCb-M5 components. The plantar tarsometatarsal ligaments were classified into five types based on the combination of their components. The pCn1-M1, pCn1-M2,3, and pCn2-M2 components were consistently observed in types I-IV (88%), along with pCn3-M3,4 in type I, pCn3-M4 and pCb-M5 in type II, and pCn3-M3 in type IV. In type V (12%), the pCn1-M1 and pCb-M5 components were consistently present. Improved comprehension of the variations in plantar tarsometatarsal ligament anatomy is expected to help diagnose diverse injuries to this region, better understand the structural pathomechanism of the injuries, and contribute to successful treatment. Clin. Anat. 32:699-705, 2019.