Bilateral Uncemented Ceramic-on-Ceramic Total Hip Arthroplasty in a 26-Year-Old Man With Morquio Syndrome

Abstract not available. Introduction provided instead.

Morquio syndrome, also known as type IV mucopolysaccharidosis, is an autosomal recessive disorder caused by deficiency of N-acetyl-galactosamine-6-sulfate. Morquio,¹ in Uruguay, and Brailsford,² in England, simultaneously described this syndrome in 1929. Its incidence is unknown but is estimated to be between 1 in 75,000 (Northern Ireland) and 1 in 200,000 (British Columbia, Canada).^3,4 Morquio syndrome is characterized by a defect in degradation of keratan sulfate and chondroitin-6-sulfate resulting in accumulation of mucopolysaccharides,
which interfere with cell function.

A child with Morquio syndrome may appear normal at birth but usually begins showing manifestations of the disease between ages 2 years and 4 years. Major orthopedic problems result from a unique spondyloepiphyseal dysplasia and ligament laxity. There is severe growth retardation with short-trunked dwarfism, genu valgum, lumbar and thoracic kyphosis, abnormal hip development, and malalignment of the lower limbs.⁵ The pelvis typically shows both acetabular and femoral head dysplasia with varying degrees of hip subluxation, short and wide femoral necks with valgus deformity, and a wide symphysis pubis. Odontoid hypoplasia may lead to atlantoaxial instability, which can give rise to myelopathy, quadriplegia, and even sudden death.⁶

Other features are aortic valve incompetence, aortic stenosis, hepatomegaly, splenomegaly, inguinal hernia, mixed hearing loss, and ocular complications, particularly clouding of the corneas. Pulmonary complications include a restrictive defect, caused by kyphoscoliosis, which can result in pulmonary hypertension and cor pulmonale.

Although hip dysplasia leading to degenerative arthritis is one of the most significant orthopedic manifestations in Morquio syndrome, this problem has not received much attention in the literature. In the present article, we report the case of an active 26-year-old man with Morquio syndrome and advanced degenerative hip arthritis managed with bilateral uncemented ceramic-on-ceramic total hip arthroplasty (THA), followed up for 5 years. In this first English-language report on use of bilateral uncemented THA in Morquio syndrome, we highlight the unique aspects of the case.