Is the Apert foot an overlooked aspect of this rare genetic disease? Clinical findings and treatment options for foot deformities in Apert syndrome

BACKGROUND: Apert syndrome is characterised by the presence of craniosynostosis, midface retrusion and syndactyly of hands and feet, thus, synonymously referred to as acrocephalosyndactyly type I. Considering these multidisciplinary issues, frequently requiring surgical interventions at an early age, deformities of the feet have often been neglected and seem to be underestimated in the management of Apert syndrome. Typical Apert foot features range from complete fusion of the toes and a central nail mass to syndactyly of the second to fifth toe with a medially deviated great toe; however, no clear treatment algorithms were presented so far. This article reviews the current existing literature regarding the treatment approach of foot deformities in Apert syndrome. STATE-OF-THE-ART TOPIC REVIEW: Overall, the main focus in the literature seems to be on the surgical approach to syndactyly separation of the toes and the management of the great toe deformity (hallux varus). Although the functional benefit of syndactyly separation in the foot has yet to be determined, some authors perform syndactyly separation usually in a staged procedure. Realignment of the great toe and first ray can be performed by multiple means including but not limited to second ray deletion, resection of the proximal phalanx delta bone on one side, corrective open wedge osteotomy, osteotomy of the osseous fusion between metatarsals I and II, and metatarsal I lengthening using gradual osteodistraction. Tarsal fusions and other anatomical variants may be present and have to be corrected on an individual basis. Shoe fitting problems are frequently mentioned as indication for surgery while insole support may be helpful to alleviate abnormal plantar pressures. CONCLUSION: There is a particular need for multicenter studies to better elaborate surgical indications and treatment plans for this rare entity. Plantar pressure measurements using pedobarography should be enforced in order to document the biomechanical foot development and abnormalities during growth, and to help with indication setting. Treatment options may include conservative means (i.e. insoles, orthopedic shoes) or surgery to improve biomechanics and normalize plantar pressures. LEVEL OF EVIDENCE: Level V.