Although rare, a dislocated knee in a newborn may be related to the position in the womb before birth. This defect can also occur in children who have Larsen syndrome, which consists of many dislocated joints (elbows, hips, and knees), clubfoot Clubfoot and Other Foot Defects Clubfoot (talipes equinovarus) is a birth defect in which the foot and ankle are twisted out of shape or position. The usual clubfoot is a down and inward turning of the hind foot and ankle... read more 
, and characteristic facial features (such as a prominent forehead, sunken nose, and wide-spaced eyes). It can also occur in children who have arthrogryposis multiplex congenita Arthrogryposis Multiplex Congenita Arthrogryposis multiplex congenita refers to a variety of conditions that involve limited joint movement. Any condition that impairs the movement of the baby while in the womb can result in... read more 
.
When the infant is examined, doctors find that the leg cannot be bent more than a few degrees.
Immediate treatment with physical therapy Physical Therapy (PT) Physical therapy, a component of rehabilitation, involves exercising and manipulating the body with an emphasis on the back, upper arms, and legs. It can improve joint and muscle function, helping... read more (flexing the infant's leg every day) and splinting the leg in a bent position usually results in a functional knee. Treatment is more complex in infants who have Larsen syndrome, arthrogryposis multiplex congenita, or other problems.
(See also Introduction to Birth Defects of the Face, Bones, Joints, and Muscles Introduction to Birth Defects of the Face, Bones, Joints, and Muscles Birth defects of the face and limbs are fairly common. They may involve only a specific body part, such as the mouth (cleft lip or cleft palate) or foot (clubfoot). Or they may be part of a... read more .)
