title: Lateral Sesamoid Position Relative to the Second Metatarsal in Feet With and Without Hallux Valgus: A Prospective Study.
abstract: We sought to determine whether hallux valgus displaces the sesamoid bones laterally away from a stationary first metatarsal or whether the first metatarsal head is displaced medially from the stationary sesamoids, which remain in position relative to the rest of the forefoot. We reviewed weightbearing radiographs in the dorsal plantar view of 128 consecutive patients (149 feet) seen over 2 months in 2014. Of these, 82 feet (55%) had a hallux valgus angle of >15° (hallux valgus group) and 67 feet (45%) had an angle of no more than 15° (control group). We measured the absolute distances from the center of the lateral sesamoid and the first metatarsal head to the long axis of the second metatarsal. Next, the relative distances, defined as the ratio of these 2 absolute distances to the length of the second metatarsal, were calculated to adjust for foot size. Both the absolute and the relative distances from the center of the first metatarsal head to the second metatarsal differed significantly between the 2 groups and correlated positively with the hallux valgus angle and first intermetatarsal angle. However, neither the absolute nor the relative distance to the lateral sesamoid bone differed significantly between the groups, nor did they correlate with either of the 2 angles. Thus, despite medial shifting of the first metatarsal in hallux valgus, the lateral sesamoid retains its relationship to the second metatarsal in transverse plane. Its apparent lateral movement is a radiographic misinterpretation. Awareness of this misinterpretation should improve the success of corrective surgery.
authors.affiliation: Resident, Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Geng
authors.affiliation: Attending Physician, Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Professor, Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai, China. Electronic address: hsmaxin@163.com.
authors.forename: Xin
authors.initials: X
authors.lastname: Ma
authors.affiliation: Associate Professor, Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Wang
authors.affiliation: Attending Physician, Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Jiazhang
authors.initials: J
authors.lastname: Huang
authors.affiliation: Resident, Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Xu
authors.affiliation: Resident, Department of Orthopedics, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006215:Hallux Valgus / Q000000981:diagnostic imaging* / Q000601:surgery; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D008297:Male; D008682:Metatarsal Bones / Q000000981:diagnostic imaging* / Q000601:surgery; D008683:Metatarsophalangeal Joint / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D008875:Middle Aged; D010027:Osteotomy; D011379:Prognosis; D011446:Prospective Studies; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology*; D012716:Sesamoid Bones / Q000000981:diagnostic imaging* / Q000601:surgery; D055815:Young Adult
keywords: dorsal plantar radiographs; hallux valgus; second metatarsal; sesamoid subluxation