Multiple epiphyseal dysplasia.

Multiple epiphyseal dysplasia is a genotypically and phenotypically heterogeneous disorder affecting the epiphysis of long bones. Inheritance may be autosomal dominant or autosomal recessive. Autosomal dominant variants include mutations of the collagen oligomeric matrix protein, collagen type IX α-1, collagen type IX α-2, collagen type IX α-3, and matrilin-3 genes. The autosomal recessive variant is caused by a mutation of the sulfate transporter gene SLC26A2. These mutations cause disorganized endochondral ossification of the epiphysis, ultimately leading to destruction of the articular cartilage. Patients typically present in childhood, but some may not present until early adulthood. A presumptive diagnosis can be made with clinical history, physical examination, detailed family history, and radiographic findings. Definitive diagnosis requires genetic testing. Treatment is based on the age of the patient, the amount of limb deformity, the level of joint destruction, and the needs of the patient. Children can greatly benefit from limb realignment procedures, and adults can have excellent outcomes with joint arthroplasty.