Deep branch of medial plantar artery

The deep branch of the medial plantar artery (MPA) is a significant vascular structure in the foot. The MPA typically bifurcates into a superficial branch and a deep branch. The deep branch of the MPA courses along the deep surface of the abductor hallucis muscle (AHM), supplying its proximal part. This branch is crucial for the vascularization of the medial side of the sole of the foot.

In a study by Macchi et al., three main patterns of the MPA were described[1]:

• In Pattern A (54%) the MPA divides into two branches. The deep branch reaches the deep surface of the AHM, supplying its proximal part, and the superficial branch courses between the AHM and the flexor digitorum brevis, to end as the first plantar metatarsal artery. The latter supplies two to three small branches to the distal part of the AHM. The fibers of the AHM end symmetrically on the two sides of the tendon and the muscle presents an arciform shape.

• In Pattern B (38%), The MPA lacks a deep branch and continues along the lateral border of the AHM as a superficial branch that supplies proximal and distal collaterals to the muscle. The muscle fibers of the AHM end mainly on the medial side of the tendon. The muscle belly presents an arciform shape and is located on the medial margin of the foot superomedially with respect to Pattern A.

• In Pattern C (8%) the MPA continues as a large deep branch on the deep surface of the AHM and ends as the medial collateral artery of the big toe. A smaller superficial branch of the MPA provides a few collaterals to the AHM from its proximal part and to the flexor digitorum brevis in its distal part.

Another study by Masadeh et al. found that the MPA bifurcates into superficial and deep branches in 81% of specimens, with the deep branch providing significant vascular supply to the medial plantar region.[2] This deep branch is critical for the viability of medial plantar artery flaps used in reconstructive surgeries.