Figure 2.

The metatarsal-sesamoid position is typically measured on a 7-point scale and increases with progressive deformity of the first metatarsal in a medial direction. In a well-aligned 1st metatarsal-phalangeal joint, the tibial sesamoid lies completely medial to the longitudinal bisection of the first metatarsal, whereas with significant deformity the tibial sesamoid may lie completely lateral to the longitudinal bisection of the first metatarsal. It may help to visualize the sesamoids lying in the stationary position while the metatarsal translates off of them medially during deformity progression, and then the surgical procedure moves the metatarsal back on top of them during deformity correction.

[Figure reprinted with permission from Ramdass R, Meyr AJ. The multiplanar effect of first metatarsal osteotomy on sesamoid position. J Foot Ankle Surg. 2010 Jan–Feb; 49(1): 63–7.]