The Os Peroneum incidence - A cadaveric study.

BACKGROUND: The Os Peroneum (OP) is a small sesamoid bone, which can be found in the Peroneus Longus Tendon (PLT) sheath, near the calcaneocuboid joint. Size and shape variability is quite common as well as a multipartite OP that can be found in some cases. Trying to explore and understand this variability, this study was carried out in order to provide us with answers about the presence and shape of OP in our specimens. METHODS: Twenty cadaveric lower extremities were obtained according to the body donation program of our institution. Dissections were performed to expose the OP (when present) starting proximally at the origin of the PLT and Peroneal Brevis Tendon (PBT) finalizing at the insertion of the PLT in the first metatarsal. RESULTS: In twenty feet, nine distinct OP were found, whilst six feet had a thickening of the tendon. On the remaining five foot, we did not identify an OP. CONCLUSIONS: In this study, 45% of the feet analyzed had an OP. The authors believe the variability of OP prevalence reported in the literature can be associated with differences in its definition.

Insertional anatomy of peroneal brevis and longus tendon - A cadaveric study.

BACKGROUND: Peroneal Tendon (PT) complex is formed by the Peroneus Longus Tendon (PLT) and Peroneus Brevis Tendon (PBT), their synovial sheath, the superior and inferior retinaculum, and the Os Peroneum (OP). Their insertion is associated with some anatomic variability. Knowing these variants helps to understand the PT pathology and it may support the decision-making concerning the operative approach. The purpose of this study was to assess anatomical variability in PT insertion. METHODS: Twenty fresh-frozen cadaveric feet were used. The lateral part of the ankle, foot and sole were dissected to expose PLT and PBT course and distal insertions. RESULTS: Concerning the PBT, eleven feet had a normal insertion in the base of the fifth metatarsal; the other nine had a variability. Regarding the PLT, thirteen out of twenty had the normal insertion in the first metatarsal; the remaining seven had anatomical variants. CONCLUSIONS: In this study, we found a great variability in the insertional anatomy of PBT and PLT. CLINICAL RELEVANCE: It is important that orthopedic surgeons are aware of the great variability of PT anatomical insertion when performing foot and ankle surgery, in order to avoid possible complications, for instance a PLT injury during preparation of tarso-metatarsal arthrodeses.