The incidence of biphalangeal fifth toe: Comparison of normal population and patients with foot deformity

The Prevalence of Biphalangealism for Each Toe in the Turkish Population: An Epidemiologic Study

BACKGROUND

Biphalangealism has been evaluated in many studies and has been shown as a common variant. Its frequency varies according to the populations. This epidemiological study aimed to determine the prevalence of biphalangealism for each toe in the Turkish population and compare it with other populations.

METHODS

The local hospital radiological database was searched for all consecutive foot radiographs, obtained between 2014 and 2018. Anteroposterior (AP) and oblique radiographs obtained to evaluate trauma or foot pathologies were included. Two-phalangeal toes according to radiographical views were defined as biphalangeal and other three-phalangeal toes were defined as normal.

RESULTS

A total of 2,881 radiographs of 2,710 adult patients met the incusion criteria. There were 1,558 (57.5%) female and 1,152 (42.5%) male patients. The cases were unilateral in 2,539 patients and bilateral in 171 patients. The overall prevalence of biphalangeal third toe was 0.29%, fourth toe was 1.29%, and fifth toe was 23.3%.

CONCLUSIONS

The presence of pedal biphalangealism is a common variant and its frequency varies according to the populations. The exact cause is still unclear. Further studies are required to assess the clinical impact of biphalangealism.

The Prevalence of Accessory Ossicles, Sesamoid Bones, and Biphalangism of the Foot and Ankle: A Radiographic Study

Background:

Accessory ossicles, sesamoid bones, and biphalangism of toes are the most common developmental variations of the foot. These bones may be associated with painful syndromes; however, their clinical importance is not well understood because the reported prevalence varies widely. Therefore, we aimed to investigate these variants in Turkish subjects.

Methods:

A total of 1651 foot radiographs were retrospectively assessed. Radiographs of feet were examined regarding the prevalence, sex, and bilaterality of accessory ossicles, sesamoid bones, and biphalangism in Turkish subjects.

Results:

Accessory ossicles (26.1%) and sesamoid bones (8%) were detected. The most common accessory ossicles were os trigonum (9.8%), accessory navicular bone (7.9%), and os peroneum (5.8%). Also, we detected os supratalare (0.48%), os calcanei secundarium (0.42%) os subfibulare (0.42%), os supranaviculare (0.36%), os vesalianum (0.30%), os subtibiale (0.24%), os intermetatarseum (0.12%), and os subcalcis (0.12%). We observed bipartite hallux sesamoid in 1.8% and interphalangeal sesamoid bone of the hallux in 0.7% of radiographs. Incidences of metatarsophalangeal sesamoid bones were found as 0.6%, 0.06%, 0.6%, and 5.8% in the second, third, fourth, and fifth digit, respectively. We observed biphalangeal toe in 0.5%, 1.7%, 3.5%, and 37.6% in the second, third, fourth, and fifth toe, respectively.

Conclusion:

This study is the first detailed report on the incidence of the most common variants of the foot and ankle in a wide-ranging patients’ series in Turkish subjects. Our study’s findings will contribute to reducing misdiagnosis.

Clinical Relevance:

The results of this study may provide anatomical data that could help clinicians in the diagnosis and management of disorders that present with pain and discomfort in the feet. Knowledge of these variants is important to prevent misinterpreting them as fractures.