Anat Cell Biol.  2023 Sep;56(3):401-403. 10.5115/acb.23.092.

Separated muscle belly of the flexor digitorum brevis for the fifth toe: a case report

• Park HJ
• Baeg JW
• Hur MS

• KMID: 2546470
• DOI: http://doi.org/10.5115/acb.23.092

Abstract

This case report describes a variation of the flexor digitorum brevis (FDB) with a separated muscle belly and tendon at the fifth toe. The narrow tendon and muscle belly for the fifth toe arose from the intermuscular septum between the FDB and abductor digiti minimi adjacent to the arising fibers of the FDB, separating from its other fibers. The tendon and muscle belly for the fifth toe became wider at the base of the metatarsal bones and narrower as it coursed toward the toes in a fusiform shape. The tendon and muscle belly for the fifth toe became thin at the midfoot and coursed just beneath the flexor digitorum longus tendon and entered the digital tendinous sheath. FDB variations including that described herein should be considered when performing various surgical procedures and evaluating the biomechanics of the foot.

Keyword

Flexor digitorum brevis; Fifth toe; Muscle belly; Tendon; Variation

Figure

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  Fig. 1 Separated muscle belly (arrowheads) and tendon (arrows) of the FDB for the fifth toe. The narrow tendon and muscle belly for the fifth toe arose from the intermuscular septum between the FDB and ADM adjacent to the arising fibers of the FDB, separating from its other fibers. The tendon and muscle belly for the fifth toe became wider at the base of the metatarsal bones and narrower as it coursed toward the toes in a fusiform shape. The tendon and muscle belly for the fifth toe became thin at the midfoot and coursed just beneath the flexor digitorum longus tendon and entered the digital tendinous sheath. The other FDB fibers were cut at the digital tendinous sheath of the toes and were reflected posteriorly. FDB, flexor digitorum brevis; ADM, abductor digiti minimi; AH, abductor hallucis; FDL, flexor digitorum longus; LPN, lateral plantar nerve; MPN, medial plantar nerve; TN, tibial nerve; QP, quadratus plantae.

Reference

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