Fairbanks disease or multiple epiphyseal dysplasia (MED) is a rare genetic disorder (dominant form: 1 in 10,000 births) that affects the growing ends of bones. Long bones normally elongate by expansion of cartilage in the growth plate (epiphyseal plate) near their ends. As it expands outward from the growth plate, the cartilage mineralizes and hardens to become bone (ossification). In MED, this process is defective. Signs and symptoms
Children with autosomal dominant MED experience joint pain and fatigue after exercising. Their x-rays show small and irregular ossifications centers, most apparent in the hips and knees. There are very small capital femoral epiphyses and hypoplastic, poorly formed acetabular roofs. A waddling gait may develop. Knees have metaphyseal widening and irregularity while hands have brachydactyly (short fingers) and proximal metacarpal rounding. Flat feet are very common. The spine is normal but may have a few irregularities, such as scoliosis.By adulthood, people with MED are of short stature or in the low range of normal and have short limbs relative to their trunks. Frequently, movement becomes limited at the major joints, especially at the elbows and hips. However, loose knee and finger joints can occur. Signs of osteoarthritis usually begin in early adulthood.Children with recessive MED experience joint pain, particularly of the hips and knees, and commonly have deformities of the hands, feet, knees, or vertebral column (like scoliosis).
Diagnosis
Diagnosis should be based on the clinical and radiographic findings and a genetic analysis can be assessed. Treatment
Symptomatic individuals should be seen by an orthopedist to assess the possibility of treatment (physiotherapy for muscular strengthening, cautious use of analgesic medications such as nonsteroidal anti-inflammatory drugs). Although there is no cure, surgery is sometimes used to relieve symptoms. Surgery may be necessary to treat misalignment of the hip (osteotomy of the pelvis or the collum femoris) and, in some cases, malformation (e.g., genu varum or genu valgum). In some cases, total hip replacement may be necessary. However, surgery is not always necessary or appropriate.Sports involving joint overload are to be avoided, while swimming or cycling are strongly suggested. Cycling has to be avoided in people having ligamentous laxity. Weight control is suggested.The use of crutches, other deambulatory aids or wheelchair is useful to prevent hip pain. Pain in the hand while writing can be avoided using a pen with wide grip. History
Multiple epiphyseal dysplasia was described separately by Seved Ribbing and Harold Arthur Thomas Fairbank in the 1930s.In 1994, Ralph Oehlmanns group mapped MED to the peri-centromeric region of chromosome 19, using genetic linkage analysis. Michael Briggs group mapped PSACH to the same area. COMP gene was firstly linked to MED and PSACH in 1995. In 1995, the group led by Knowlton did a "high-resolution genetic and physical mapping of multiple epiphyseal dysplasia and pseudoachondroplasia mutations at chromosome 19p13.1-p12. "Research on COMP led to mouse models of the pathology of MED.