Key Insights On Conservative And Surgical Management Of Ectrodactyly

Having never seen ectrodactyly outside of textbooks and journals, I was intrigued when a patient presented to clinic with split-hand/split-foot malformation. She was the third generation in her family with the deformity, having inherited it from her mother.

Ectrodactyly is a congenital limb deformity characterized by a deep median cleft of the hand and/or foot with an absence of the central rays.^1,2 Other names for this include ectrodactyly-ectodermal dysplasia-clefting syndrome or split-hand/split-foot malformation.^1,3 When there is ectrodactyly in the foot, one may see syndactyly of the digits, median clefts of the feet or aplasia/hypoplasia of the phalanges or metatarsals.¹ Any number of the three central rays can be affected.² Accordingly, split-hand/split-foot malformation may present in a variety of ways with some cases having greater deformity than others.

Split-hand/split-foot malformation is one of the most common types of hereditary ectodermal dysplasias.³ Ectodermal dysplasia is the abnormality of two or more of the organs that arise from the ectoderm. This can include abnormalities in the hair, teeth, finger and toenails, sweat glands, conjunctiva, tear ducts, external ear and the central nervous system. Dermatologically, patients with ectrodactyly-ectodermal dysplasia-clefting syndrome may present with fine hair, dermatitis or folliculitis, thickening and yellowing of all 10 fingernails and toenails, and/or hyperkeratosis of the palms and soles.⁴

Split-hand/split-foot is most commonly inherited in an autosomal-dominant pattern with reduced penetrance.¹ In the autosomal-dominant form with bilateral cleft hands and cleft feet, the incidence is reportedly 1 in 90,000.² In some cases, however, ectrodactyly may result from random chromosomal deletions and duplications, leading to unilateral cleft hands or feet.^1,2 Sporadic gene mutation is even rarer with an incidence of 1 in 150,000.²

Blauth and Borisch proposed a classification system that is in wide use for describing split foot deformities.⁵ This classification system is based on the presence or absence of the metatarsal bones (see image below).

A Closer Look At Conservative Treatment

From a standpoint of ambulation, most patients are able to function just fine and have no difficulty with walking.⁵ Patient complaints with split-hand/split-foot malformation usually center around the inability to wear normal shoes. Conservative treatment may begin with shoe modifications to alleviate discomfort. Patients may be required to purchase wider or larger shoes to accommodate the deformity.

Our patient with split-hand/split-foot malformation purchased a pair of soft Ugg brand boots. These boots allowed her to have pain-free ambulation throughout the winter months because of the soft lamb’s wool material. In the summer, she often transitioned into a pair of open toe sandals that strapped around the ankle. 

Custom orthotics can facilitate better propulsion.^5,6 These can have a filler to accommodate for missing metatarsals or a median cleft.⁶ One can add additional felt, lamb’s wool or Plastazote-type foam padding in areas prone to callus formation. Patients may develop painful calluses that require frequent debridement. It is common for patients to experience bursitis pain of the unaffected metatarsophalangeal joints. Bursitis may respond well to local steroid injection or padding and offloading.

When Patients With Ectrodactyly Need Surgery

Authors have proposed a variety of surgical treatments, most of which focus on syndactylization and/or amputation of the deformity.⁵ As with conservative treatment, surgical interventions should be patient specific and based on the present deformities. Surgical intervention should ideally create a more normal-sized foot, fill the cleft and correct any other deformities while maintaining good ambulation and function.⁵ Give special consideration in the pediatric population to obtain a more acceptable cosmetic result because of the potential psychological impact of this deformity.⁷ 

In patients with Blauth and Borisch type I-III deformities, in which there is little to no central ray deficit, one may close the cleft via simple syndactylization.⁸ Unfortunately, simple closure becomes more difficult as the central ray deficit increases. Authors have proposed staged surgical correction in more difficult cases with the first stage reducing the width of the foot and the second stage addressing digital abnormalities.⁹

Abraham and colleagues proposed a clinical classification system with subsequent surgical recommendations.¹⁰ Type I feet had a central ray deficiency extending to the mid-metatarsal level without splaying or the medial or lateral rays. The authors recommended correction with soft tissue syndactylization and hallux valgus correction if indicated. Type II had a deeper cleft up to the tarsal bones with forefoot splaying. The correction for this was the same as that for type I if the patient was 5 years old or younger. For patients over the age of 5, the authors suggest first ray amputation.¹⁰ Type III patients demonstrated the complete absence of the first through third or fourth rays. These patients did not require surgical intervention, according to the classification.

Our patient is not currently amenable to surgery as her mother had a painful and complicated syndactylization. We will continue with shoe modifications and conservative care for the patient.

References

1. Duijf PHG, Bokhoven HV, Brunner HG. Pathogenesis of split-hand/split-foot malformation. Human Molecular Genetics. 2003; 12(1):R51-R60.
2. Choudry Q, Humar R, Turner PG. Congenital cleft foot deformity. Foot Ankle Surg. 2010; 16(4):e85-e87.
3. Leon-Mateos A, Monteagudo B, Rodriguez L, Suarez I, Zulaica A. Patient with “lobster claw” hands and feet: ectrodactyly-ectodermal dysplasia-clefting syndrome. Actas Dermosifiliogr. 2008;99(6):822-23.
4. Available at https://nfed.org/uploads/Clouston%20Syndrome.pdf .
5. Blauth W, Borisch NC. Cleft feet: proposals for a new classification based on roentgenographic morphology. Clin Orthop. 1990;258:41-8.
6. Caselli M. Ectrodactyly of the foot. Podiatry Management. 2009; 28(1):165-172.
7. Pena DA, Nova AM, Pena JA, Ruiz SH. Cleft foot and ectrodactyly-ectodermic dysplasia- cleft lip/palate syndrome: review of the literature and report of two new cases. The Foot. 2004; 14(2):221-226.
8. Sumiya N, Onizuka T. Seven years’ survey of our new cleft foot repair. Plast Reconstr Surg. 1980; 65(4):447-59.
9. Tani Y, Ikula Y, Ishida O. Surgical treatment of the cleft foot. Plast Reconstr Surg. 2000; 105(6):1997-2002.
10. Giorgini RJ, Capa CJ, Potter GK. Two stage surgical correction of cleft foot. J Am Podiat Med Assoc. 1985;75(9):481-7.
11. Abraham E, Waxman B, Shirali S, Durkin M. Congenital cleft foot deformity treatment. J Pediatr Orthop. 1999; 19(3):404-410.