Bone and Joint Dysplasias
Dysplasia is a term literally meaning abnormal growth. Applied to the skeletal system, the term encompasses a heterogenous group of >400 conditions in which abnormalities of growth can affect the epiphysis, metaphysis, physis, or diaphysis of developing bone and are broadly grouped under the heading of osteochondrodysplasias. Although each individual syndrome is rare, collectively the overall incidence is 1 in 5000 births. These dysplasias are heritable and can range in severity from devastatingly symptomatic or even fatal to mere radiologic curiosities. They should be considered in any individuals with disproportionate short stature and/or early-onset osteoarthritis. Many have head and facial dysmorphisms. The genetic cause has been identified for at least 56 of these disorders. Early identification allows initiation of treatment and genetic counseling.
- 1. An osteochondrodysplasia should be considered in any patient with premature osteoarthritis and/or disproportionate short stature.
- 2. Hypophosphatasia may mimic rickets and osteomalacia and is associated with low alkaline phosphatase (ALP) levels. Adults with milder disease frequently have a history of poorly healing metatarsal stress fractures.