The diagnosis can be made by fetal ultrasound by progressive discordance between the short femur length and biparietal diameter by age. The trident hand configuration can be seen if the fingers are fully extended.Another common characteristic of the syndrome is thoracolumbar gibbus in infancy. Treatment
There is no known cure for achondroplasia even though the cause of the mutation in the growth factor receptor has been found. Although used by those without achondroplasia to aid in growth, human growth hormone does not help people with achondroplasia, which involve a different hormonal pathway. Usually, the best results appear within the first and second year of therapy. After the second year of growth hormone therapy, beneficial bone growth decreases, so the therapy is not a satisfactory long-term treatment. As of December 2020, the treatment of achondroplasia with human growth hormone was approved only in Japan.An experimental drug called vosoritide has shown promise in stage 3 human trials, although its long-term effects are unknown.Limb-lengthening will increase the length of the legs and arms of someone with achondroplasia,  but little medical consensus exists regarding this practice. The age of surgery can vary from early childhood to adulthood.Research has also shown that introducing parents of children with achondroplasia to support and advocacy groups at the time of diagnosis can improve outcomes. Several patient advocacy groups exist to support people with achondroplasia and their families. Epidemiology
Achondroplasia is one of several congenital conditions with similar presentations, such as osteogenesis imperfecta, multiple epiphyseal dysplasia tarda, achondrogenesis, osteopetrosis, and thanatophoric dysplasia.
Diagnosis
Achondroplasia can be detected before birth by prenatal ultrasound, although signs are often subtle and not apparent before the 24th week of pregnancy. A DNA test can be performed before birth to detect homozygosity, wherein two copies of the mutant gene are inherited, a lethal condition leading to stillbirths. Postnatal diagnosis of achondroplasia is typically uncomplicated, involving an assessment of physical and radiographic features. Clinical features include megalocephaly, short limbs, prominent forehead, thoracolumbar kyphosis and mid-face hypoplasia. Complications like dental malocclusion, hydrocephalus and repeated otitis media can be observed. The risk of death in infancy is increased due to the likelihood of compression of the spinal cord with or without upper airway obstruction. Radiologic findings
A skeletal survey is useful to confirm the diagnosis of achondroplasia. The skull is large, with a narrow foramen magnum, and relatively small skull base. The vertebral bodies are short and flattened with relatively large intervertebral disk height, and there is congenitally narrowed spinal canal. The iliac wings are small and squared, with a narrow sciatic notch and horizontal acetabular roof. The tubular bones are short and thick with metaphyseal cupping and flaring and irregular growth plates. Fibular overgrowth is present. The hand is broad with short metacarpals and phalanges, and a trident configuration. The ribs are short with cupped anterior ends. If the radiographic features are not classic, a search for a different diagnosis should be entertained. Because of the extremely deformed bone structure, people with achondroplasia are often "double jointed".