Orthopaedic manifestations of chondroectodermal dysplasia: the Ellis-van Creveld syndrome

Ellis-van Creveld is a dwarfing syndrome transmitted as an autosomal recessive trait. The constant features of the condition include acromelic-micromelic dwarfism, ectodermal dysplasia involving the nails, teeth and gums, postaxial polydactyly of the hands and congenital heart disease. Congenital heart disease affects 50-60 % of all patients and nearly 50 % of patients die by 18 months of age from cardiopulmonary complications. This study is intended to characterise the orthopaedic manifestations of Ellis-van Creveld based on the authors' unique opportunity to interview and examine the largest group of patients to date in the literature.

Detailed interviews, physical examinations and/or radiographs were available on 71 cases of Ellis-van Creveld syndrome. Data were collected from physical examinations, radiographs, computed tomography (CT) reconstruction and magnetic resonance imaging (MRI) of the knee. Pathoanatomy of the knee was reinforced by the direct surgical observation of 25 limbs surgically managed during adolescence and puberty.

A number of interesting clinical and radiographic abnormalities were noted in the upper extremities and lower extremities, but by far the most significant orthopaedic finding was a severe and relentlessly progressive valgus deformity of the knee. Although many patients had difficulties making a "fist" with the hand, no patient reported any functional disability. The severe valgus deformity of the knee is the result of a combination of profound contractures of the iliotibial band, lateral quadriceps, lateral hamstrings and lateral collateral ligament, leading to lateral patellar subluxation and dislocation. The lateral portion of the upper tibial plateau presents with cupping and progressive depression of the lateral plateau, along with severe valgus angulation of the proximal tibia and fibula. A proximal medial tibial exostosis is seen in nearly all cases.

This is the largest group of Ellis-van Creveld syndrome patients identified in the literature. An understanding of the orthopaedic pathoanatomy of the knee deformity is critical to determining the appropriate surgical management. This paper characterises the orthopaedic manifestations of Ellis-van Creveld syndrome and especially identifies the pathoanatomy of the severe and progressive valgus knee deformity.

Level II.