SONOGRAPHIC ANATOMY AND SONOGRAPHIC MEASU REMENT OF THE TRANSVERSE ARCH OF THE FOOT

A new and original sonographic technique to document the morphology of normal feet and splay feet is presented: a standard sectional plane c uts the transverse arch from the plantar side using the sesamoids of t he first metatarsal bone and the head of the fifth metatarsal bone as reference points. A 5-MHz linear transducer and a rather simple custom -made platform with an integrated gelpad are required in order to get reproducible results. The morphology of the transverse arch can be cha racterized by the ''transverse arch index Q'' as the parameter of the relative height of the transverse arch. Based on this transverse arch index Q, splay feet can be distinguished from normal feet in a statist ically significant way (p < 0,01). Furthermore, grading of splay feet is possible and a documentation of rigidity/flexibility of the forefoo t in splay feet; thus, the decision on whether to use conservative or operative treatment can additionally be based on sonographic documenta tion, and the results of surgical reconstruction of the transverse arc h can be checked and documented sonographically.