Clinodactyly: Causes, Symptoms, Diagnosis, and Treatment

abnormally bent or curved finger

It’s a term used to describe the abnormal curvature of a digit or finger caused by genetic issues.

Medical texts describe this condition as a rare congenital disorder associated with Down Syndrome. In this regard, 25% of children with Down Syndrome are prone to develop Clinodactyly.

This condition consists of an abnormally bent or curved finger, usually the 5th finger (commonly known as the “little finger” or “pinky”). The joint closest the nail bed ends up getting angulated toward the ring finger (or 4th finger).

It occurs because the bones in the finger change direction as they grow, and that results in trapezoidal or triangular shaped bones shifting the alignment of the affected digit.

Researchers are not entirely sure about the exact incidence of Clinodactyly because it’s somewhat hard to define the level of digit curvature experts can consider abnormal.

This condition is more prevalent in boys than girls; and while it usually affects the 5th finger, it’s uncommon to have Clinodactyly in both hands.

Causes of Clinodactyly

Medical experts consider that Clinodactyly is a congenital condition. Several people think this condition is related to other genetic disorders such as the ones listed here below:

Down Syndrome, which is a genetic disorder that results in intellectual impairment as well as physical abnormalities. The cause of this condition is the presence of a third copy of chromosome 21 instead of the usual two copies.

Klinefelter Syndrome, also known as XXY Syndrome, is a condition that affects male patients. The cause of this disorder is the presence of an additional X chromosome.

It interferes with the development of the testicles and diminishes the production of testosterone.

Turner Syndrome, it is a rare condition that affects female patients preventing their bodies from growing and maturing naturally. It occurs because of the complete or partial absence of the second X chromosome.

Fanconi Anemia, it is a term used to describe a rare genetic disease that consists of bone marrow failure that may result in hand or skeletal abnormalities along with a wide variety of physical characteristics.

Symptoms of Clinodactyly

The most noticeable sign of this condition is the abnormally curved finger. In most cases, Clinodactyly does not cause any pain or discomfort, neither does it feature swelling or inflammation.

However, if the curvature of the affected finger (usually the 5th one) exceeds 30°, then the function of the hand may get impaired. If this joint’s bent shape gets around 45° or above, then the 4th finger can start bending as well.


In some hospitals and medical centers, the first step a doctor or a general practitioner (GP) may take to confirm cases of Clinodactyly is performing a physical examination of the child’s finger and hand.

More often than not, medical experts recommend an X-ray to confirm a diagnosis of Clinodactyly.

The X-ray is one of the most common imaging tests used around the world. It produces images of bones, which can help clinicians or GPs to identify and examine the underlying structures of the hand.

When it comes to patients with Clinodactyly, doctors usually perceive a distinctive c-shaped bone in the middle structure of the affected finger.

Sometimes, after a thorough medical history, physical examination, and X-ray imaging, doctors may perform a Range of Motion (ROM) Testing, which refers to the measurement of movement around a joint.

Clinicians can use it to determine if the condition is affecting movement and dexterity around the affected area.


After performing an accurate diagnosis, medical experts can determine which is the best way to proceed based on the child’s age, the severity of the condition, the kid’s tolerance to any particular treatment, and the parents’ opinion.

Mild finger curvature doesn’t cause any significant functional problem, so these cases don’t require surgical treatment. Doctors will recommend monitoring the patient to ensure the condition doesn’t become worse.

However, when the finger curvature reaches 30° or above, it will likely impair the function of the hand and negatively impact daily activities.

In such cases, medical experts recommend surgery while the child is still young and the bones are still developing.

The surgical treatment used to deal with Clinodactyly consists of a phalanx-opening wedge osteotomy procedure.

It involves removing the wedge-shaped portion of the curved bone, stabilizing the finger, and lining up bones and soft tissues properly within the affected finger.