Apert syndrome occurs in 1 of every 55,000 individuals, and is caused by a mutation in FGFR2 on chromosome 10. Although the inheritance of Apert syndrome follows an autosomal dominant pattern, most cases are isolated [1,2]. Apert syndrome combines premature craniosynostosis, midfacial bone hypoplasia, and bony brachydactyly. Therefore, during surgery for bony syndactyly with Apert syndrome, unilateral multiple interdigital formation should be avoided because of other potential complications that could occur; furthermore, Apert hand is more complex and severe than other genetic diseases, and is difficult to treat owing to its associated circulation as well as the potential for infection [1,2].

Webplasty for syndactyly is usually conducted with a combination of full-thickness skin grafts and various local flaps; however, this may be associated with problems such as large areas requiring full-thickness skin grafts or a lack of appropriate skin harvesting sites [3,4]. Apert hand is the most complex and severe form of syndactyly; therefore, its associated problems are especially serious. Skin grafting during webplasty is not considered desirable by many parents of these patients, which is why these parents often refuse such treatment. Various full-thickness skin grafting sites and local flap techniques have been researched and developed to alleviate these problems [4]. Additionally, an external fixator can be attached to the phalanx, thus extending it laterally, to perform webplasty. Therefore, webplasty has been conducted for Apert hand by combining lateral extension with an external fixator and full-thickness skin grafting [5,6]. However few studies have been reported on webplasty only using an external fixator without skin graft.

During this study, we aimed to enable webplasty for Apert hand without any skin grafting. For this purpose, we created a custom-made small external fixator, inserted a fixation pin into each phalanx of two adjacent digits, and secured the soft tissue by performing lateral extension.