Clinodactyly


Clinodactyly is a medical term describing the curvature of a digit in the plane of the palm, most commonly the fifth finger towards the adjacent fourth finger.
It is a fairly common isolated anomaly which often goes unnoticed, but also occurs in combination with other abnormalities in certain genetic syndromes. The term is from the Ancient Greek κλίνειν klínein meaning "to bend" and δάκτυλος dáktulos meaning "digit".

Genetics

Clinodactyly is an autosomal dominant trait that has variable expressiveness and incomplete penetrance.
Clinodactyly can be passed through inheritance and presents as either an isolated anomaly or a component manifestation of a genetic syndrome. Many syndromes are associated with clinodactyly, including those listed below,, but the phenotype, by itself, is not a sensitive or specific diagnostic test for these syndromes.
When identified prenatally, in conjunction with other features of Down syndrome, for example during obstetric ultrasonography, it may be an indication for intrauterine sampling for fetal chromosome analysis.

Pathophysiology

Due to a developmental arrest there is an abnormal alignment of the joint surfaces at either interphalangeal joint causing angulation in the plane of the palm. The finger may be slightly bent or have a very prominent bend.

Diagnosis

There is no consensus on what degree of angulation justifies a diagnosis; an incline between 15° and 30° is typical. A similar-sounding term, camptodactyly, is a fixed flexion deformity of a digit.

Management

Treatment is only necessary if the degree of curvature is sufficient to cause disability or if it causes emotional distress. Splinting does not routinely correct the deformity. Surgical treatments are closing wedge osteotomy, opening wedge osteotomy, and reversed wedge osteotomy. Radiographs of the fingers are useful in planning the surgical procedure. Severe clinodactyly may require soft tissue alterations to the digit such as release of skin, extensor tendon relocation, and collateral ligament advancement.

Epidemiology

Minor degrees of curvature are common. Reports of incidence vary between 1% and 19.5%.