Prevalence of Morton's toe:  a systematic review and meta-analysis

When the second toe is longer than the big toe, it is referred to as Morton's toe. Although the occurrence of Morton's toe is considered normal and seen across many populations, its prevalence and associated risks have not been sufficiently explored. Some studies reported a very high occurrence of Morton's toe, whereas others reported it to be low. These differences in prevalence of Morton's toe and lack of a standard dataset regarding the associated risks of Morton's toe made us to perform a systematic review and meta-analysis on the prevalence of Morton's toe.

A systematic literature search was performed in Google Scholar, MEDLINE, PubMed, SciELO, and ScienceDirect data bases using "Morton's Toe" AND "Risks" AND "Prevalence," search terms adopting PRISMA guidelines.

Literature search yielded 935 article links, of which five studies met the inclusion criteria. These five studies comprised of 2636 feet, which were in the age range of 16-90 years. Our pooled analysis revealed that the prevalence of Morton's toe was 40% and in different populations, it was ranging from 28-66%. Statistical heterogeneity among studies was extremely high, with a heterogeneity of I ² = 97.5%, τ ² = 0.0347 (p < 0.0001), indicating that most of the variability in prevalence estimates was due to real differences between studies rather than sampling error alone.

This study provides a comprehensive picture of the prevalence of Morton's toe, which varies from population-to-population and is associated with certain risks such as overpronation (turning inward) of the foot, bunion deformity, hammertoe, and plantar fasciitis. Open Science Framework (OSF) registration: https://doi.org/10.17605/OSF.IO/BGKY2.