Hallux varus, also commonly referred to as ''sandal gap'', is a clinical condition characterized by medial deviation of the great toe at the metatarsophalangeal joint.
This condition, when acquired by adults, is usually caused by sports injury, surgical overcorrection of
hallux valgus
A bunion, also known as hallux valgus, is a deformity of the MTP joint connecting the big toe to the foot. The big toe often bends towards the other toes and the joint becomes red and painful. The onset of bunions is typically gradual. Compli ...
, or underlying causes such as
arthritides.
A sandal gap that is congential and not caused by an injury can be a normal variant, and can be visible on a pre-natal ultrasound as early as the second trimester. However, it is also considered to be a "soft sign" associated with an increased likelihood of a genetic abnormality, including
Down's Syndrome,
CLOVES syndrome, and at least forty other rare conditions. One 2011 study of the common morphological features in
autistic
Autism, also known as autism spectrum disorder (ASD), is a neurodevelopmental disorder characterized by differences or difficulties in social communication and interaction, a preference for predictability and routine, sensory processing di ...
children (sample size of n=421) found that 59% of the children in the study had a sandal gap, the most common morphological abnormality in the group.
In places where modern shoes
whose toe boxes are excessively narrow have not been worn, normal feet can be mistaken for hallux varus.
The
sandal gap is a phenomenon in which, due to the lack of a restrictive
toe box
The toe box is the section of footwear that surrounds the toes on closed-toe shoes. Toe boxes that are too tight can cause injuries and foot deformity, foot deformities, whereas wider toe boxes may be used to treat or prevent common foot condition ...
in sandals, the toes can actuate unrestricted, so one may end up with any number of aligned and misaligned toes depending on how often one uses either sandals or narrow toe box shoes at any given time throughout one's life.
Photos
Hallux varus.jpg, Radiography
Radiography is an imaging technology, imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object. Applications of radiography include medical ("diagnostic" radiog ...
of the left foot of a young male showing progressive hallux varus
References
External links
''Related term'': sandal gap - https://www.ncbi.nlm.nih.gov/gtr/conditions/C1840069/
Foot diseases
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