Multiple Epiphyseal Dysplasia
Multiple epiphyseal dysplasia (MED) is a hereditary disorder characterized by abnormal epiphyses (bone extremities) that lead to early-onset joint pain and recurrent inflammation of cartilage and bone. There are five subtypes of MED, each with varying clinical manifestations and inheritance patterns.
Multiple epiphyseal dysplasia (MED) is a hereditary condition characterized by abnormal development of cartilage and bone. The epiphysis is the portion at the end of a long bone where growth occurs. Dysplasia is an abnormality in development leading to alteration in size, shape, and organization of cells. Thus, in MED, the epiphyses of the long bones are dysplastic and, as a result, joint pain and inflammation result. On x ray, the epiphyses will appear flattened and irregular. Cartilage in the joints becomes irregular and this leads to early-onset osteoarthritis. Patients often have short hands and stubby fingers.
MED can be divided into five subtypes, four of which are inherited in an autosomal dominant fashion (EDM1, EDM2, EDM3, and EDM5) and one of which is inherited in an autosomal recessive fashion (EDM4). All of the subtypes are characterized by early-onset joint pain, most often in the hips and knees. Most individuals with MED have adult heights that are in the low range of normal, although some may have slightly short stature.
The goal for patients with dominant MED is to decrease pain, restrict joint destruction, and prevent the development of osteoarthritis. Pain is often difficult to control in affected individuals, however, analgesics (i.e., nonsteroidal anti-inflammatory drugs) and physiotherapy have been shown to be effective in some cases. An orthopedic surgeon can advise patients on whether surgical procedures (i.e., realignment osteotomy or acetabular osteotomy) might slow the progression of symptoms. In some patients, joint replacement may be necessary. Affected patients should avoid obesity and activities that strain affected joints.
Individuals with recessive MED should seen by an orthopedist who can assess the possibility of treatment. This may include physiotherapy for the purpose of strengthening muscles, use of analgesics (i.e., nonsteroidal anti-inflammatory drugs), and the timing of surgery, if necessary. As in dominant MED, affected patients should avoid obesity and activities that strain affected joints.
Patients with dominant and recessive MED have a normal life expectancy and generally lead productive and healthy adult lives.
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Mary E. Freivogel, MS, CGC