Three-dimensional analysis of flatfoot deformity: cadaver study

Area of Science:

• Orthopedics
• Biomechanics
• Podiatry

Background:

• Flatfoot, or pes planus, is a common condition affecting foot alignment.
• Accurate assessment of tarsal alignment is essential for effective treatment.

Purpose of the Study:

• To quantitatively define the three-dimensional tarsal alignment changes in flatfoot (pes planus).
• To provide a detailed understanding of the complex deformities in flatfoot for surgical guidance.

Main Methods:

• Utilized fresh-frozen cadaver foot specimens (n=11).
• Employed a magnetic tracking system to measure the 3D position of the talus, calcaneus, navicular, and first metatarsal relative to the tibia.
• Compared alignment in intact feet versus simulated flatfoot conditions.

Main Results:

• Significant deviations in metatarsal-to-talar alignment (abduction, dorsiflexion, eversion) were observed in flatfoot.
• Calcaneal-to-talar alignment showed significant abduction and eversion.
• Navicular-to-talar alignment exhibited significant abduction, dorsiflexion, and eversion.
• Talar-to-tibial alignment showed significant dorsiflexion.
• Average arch height was reduced by 6.0 mm in the flatfoot condition.

Conclusions:

• Flatfoot deformity is complex, affecting multiple joints and all three planes of motion.
• Detailed understanding of these multi-planar alignment changes is vital for successful hindfoot reconstruction.