Medical Terminology for Overlapping Toes
The medical term for overlapping toes is "overlapping toe deformity" or simply "overlapping toe." 1, 2
Specific Terminology by Location
The most common presentation is the overlapping fifth toe, which is characterized by the proximal phalanx dorsally subluxating and adducting on the fifth metatarsophalangeal joint. 2 This is a varus deformity that usually occurs bilaterally and is often familial. 1
When the hallux (big toe) crosses over the second toe, the specific term is "hallux valgus superductus." 3 Conversely, if the hallux moves under the second toe, it is termed "hallux valgus subductus." 3
For the second toe, traumatic horizontal deviation with medial overlap can occur due to rupture of the dorsal lateral metatarsophalangeal collateral ligament and lateral interosseous tendon. 4
Clinical Context and Importance
Overlapping fifth toe deformities may be congenital and present as asymptomatic findings in children, but can become painful and disabling in both pediatric and adult populations. 2
The deformity can be classified as flexible (correctable manually) or fixed (rigid), which determines treatment approach. 5
In diabetic patients with neuropathy and foot deformities, overlapping toes require special attention to offloading areas overlying bony deformities to prevent ulceration. 6
Custom-made footwear with extra depth is often needed to accommodate deformities such as overlapping toes, typically requiring a minimum of 5 mm additional depth compared to conventional footwear. 7, 8
Common Pitfall
Do not confuse overlapping toe with underlapping toe (also called "curly toe"), which is a distinct deformity where the proximal phalanx is in varus at the metatarsophalangeal joint with flexion, often with rotational malalignment. 2