Arthrogryposis

Diagnosis

The joint abnormalities can involve all four limbs (60%), the lower limbs only (30%) or the upper limbs (10%). It is usually symmetrical but different joints may show varying degrees of involvement. Typically, there is fixed joint flexion or extension with absent movement of the extremity. However, in some cases there is only distal involvement (distal arthrogryposis) or mild restriction in the range of motion. The ability of ultrasound to diagnose these conditions will depend on the type encountered, the gestational age at examination and the presence of associated anomalies but some cases can be diagnosed in the early 2nd trimester usually on the basis of abnormal fetal movement. Prenatal findings include lack or limited fetal motion, fixed joint flexion or extension, abnormal hand position, clubfeet, clubhand, lack of extension of fingers, absent breathing movements and polyhydramnios. A wide variety of associated anomalies have been described. Joint abnormalities are frequently overlooked in the setting of multiple or severe congenital anomalies and are only diagnosed after birth. More than 100 disorders that feature different degrees of arthrogryposis have been reported.