Multiple epiphyseal dysplasia (MED), also known as Fairbank disease or multiple epiphyseal osteogenesis imperfecta (dysostosis epiphysealis multiplex), is a rare hereditary cartilage development defect characterized by abnormal ossification of multiple epiphyses, leading to growth disorders and short, thick fingers in patients. Fairbank first described this condition in 1935, noting its hereditary and familial nature. It is more common in males than females, with onset typically occurring in early childhood or adolescence. The condition most frequently affects the hip, shoulder, and ankle joints, followed by the knee, wrist, and elbow joints. The appearance of multiple irregular ossification centers causes the epiphyses to enlarge, sometimes extending into the diaphysis. Subsequently, the irregular fusion of these ossification centers results in uneven joint surfaces, leading to early-onset osteoarthritis.

bubble_chart Etiology

The cause of the disease is unknown. It is a congenital anomaly.

bubble_chart Clinical Manifestations

The main manifestations include pain in the hip and knee joints, limited mobility, difficulty walking, and a waddling gait. Shoulder joint movement is also restricted. The bone ends are often enlarged, and a few patients may exhibit joint flexion deformities or joint laxity. The hands become shorter, the fingers thicker, and the stature short. Since the disease affects the long bones of the limbs more prominently than the spine, it presents as a form of short-limbed dwarfism. Additionally, there may be genu varum, valgus deformity, unequal leg length, and kyphosis.

**X-ray Findings**: Symmetrical delayed appearance of epiphyseal ossification centers, slow development, and delayed fusion with the diaphysis. The characteristic feature is irregular ossification, with abnormal density in the ossification centers. These often appear spotty or mulberry fruit-like, with numerous small, scattered ossification centers surrounding larger ones, though not as numerous as in stippled epiphyseal dysplasia. These multiple ossification centers cause the bone ends to enlarge. The distal tibial epiphysis tilts outward, with reduced depth, and the fibula becomes elongated. The talus undergoes morphological changes to adapt to tibial deformities (seen in 50% of cases). The long bone shafts are shorter than normal, while the skull and teeth remain unaffected. It can be classified into two types: ① **Ribbing Type (Mild Form)**: Features multiple epiphyseal dysplasia, flattened epiphyses, and milder bone involvement in the hands. ② **Fairbank Type (Severe Form)**: Characterized by small, irregular epiphyses, delayed ossification of carpal bones, and significant changes in the metacarpals and phalanges.

Mainly relies on X-rays. It should be differentiated from the following diseases: ① Hypothyroidism (cretinism), with similar epiphyseal changes, but the patient's skin is dry, intellectual development is delayed, bone age is significantly delayed, and the vertebral bodies in the thoracolumbar region may show a special hook-shaped appearance. Symptoms improve after thyroid hormone treatment. ② Punctate epiphyseal dysplasia. The entire epiphysis appears as many scattered centers, more pronounced than in this disease. The talus may become scattered spots. Congenital internal visual obstruction (50%) is present. ③ Differentiation from Morquio-Brailford disease, spondyloepiphyseal dysplasia, and bilateral flat hips.

bubble_chart Treatment Measures

The disease has a tendency to improve on its own, but early-onset degenerative joint disease is inevitable. In childhood, external fixation is unnecessary, and surgery is even less advisable. Weight-bearing should be avoided when the condition is unstable. Occupations that involve minimal walking or standing should be chosen. The treatment principles for adult osteoarthritis are the same as for the general population, and corrective surgeries can be performed for conditions such as leg length discrepancy, genu varum or valgum, or spinal deformities.

bubble_chart Prognosis

In multiple epiphyseal dysplasia, the density of the epiphyses returns to normal during healing, but the irregular shape often remains partially or largely, leading to early-onset osteoarthritis in adulthood.