The Hand in Multiple Epiphyseal Dysplasia

Sunday, February 26, 2017

The Hand in Multiple Epiphyseal Dysplasia

Multiple Epiphyseal Dysplasia (MED) is an uncommon anomaly of the bone and cartilage at the ends of the bones (epiphyses) in the growing child. There are 6 primary types of Multiple Epiphyseal Dysplasia. All are transmitted in an autosomal dominant fashion except type 4.

EDM1 is caused by a heterozygous mutation in the gene encoding cartilage oligomeric matrix protein (COMP). Most common.

EDM2 -a mutation in the COL9A2 gene

EDM 3 -a mutation in the COL9A3 gene

EDM 4 -a mutation in the DTDST gene. This type is autosomal recessive whereas the others are autosomal dominant.

EDM5 -a mutation in the MATN3 gene

EDM6 -a mutation in the COL9A1 gene

Historically, the more severe type of Multiple Epiphyseal Dysplasia was known as the Fairbank type (dominant) while the more mild form was known as the Ribbing type. The Ribbing type was thought to have normal or more normal wrist and hands. These terms are no longer utilized.

The abnormal epiphysis at the bone ends leads to progressively worsening ossification and this causes joint abnormalities often leads to stiff joints and arthritis. Onset varies by the particular type- more severe types present earlier with childhood pain, often in the hip or knees but also potentially involving the hands and wrists. The fingers may be short and stiff.

The diagnosis is based on a clinical suspicion but it can be a challenging diagnosis which is based on the patient’s history and examination. An experienced orthopedic surgeon or radiologist may detect x- ray changes- this experience is the key to making the diagnosis. The diagnosis may be confirmed by genetic testing as noted above.

There is no current treatment to prevent worsening or change the course of Multiple Epiphyseal Dysplasia. Ultimately, there is a future potential for genetic intervention. Currently, hand or physical therapy may be helpful to maintain motion and surgery can be helpful to contour the bone and joints and improve motion and decrease pain.

This is the case of an 8 year old child with Multiple Epiphyseal Dysplasia. I met the patient to assess the hands and wrists which had been stiff since a young age. There was discomfort with daily activities but the biggest issue was related to function given the finger stiffness (present for many years). The clinical pictures demonstrate the finger posture (most notably PIP joint stiffness) and the x- rays confirm loss of joint spaces.