Historical Overview
- Examination of the extensor tendons is a long-established component of the routine clinical examination of the hand. The exam is used in the diagnosis of camptodactyly, as well as Kirners deformity1, Dupuytren’s disease,2 certain injuries to the digits,3 rheumatoid arthritis, and a of other diseases, disorders, and conditions.4
- The word, camptodactyly is derived from the Greek words “kampto,” which means to bend, and “daktylos,” which means finger.
- The term “camptodactyly” has been attributed to Louis Landouzy who, in 1906, described a variety of constitutionally crooked digits,5 and to RW Tamplin who, in 1846, used the term to describe a flexion deformity of the proximal interphalangeal (PIP) joint of the little finger in an antero-posterior direction.6
- Camptodactyly, meaning bent finger, is a congenital flexion deformity of the proximal PIP joint,3 typically of the little finger.
Description
- Camptodactyly, meaning bent finger, is a congenital flexion deformity of the proximal PIP joint,3 typically of the little finger. Although the term was originally used to describe contracture of the little finger, it is now used to describe the deformity in all fingers.7
- As noted camptodactyly is diagnosed primarily by observation of the patient’s little fingers. To compensate for the flexion contracture of the proximal interphalangeal (PIP) joint, the patient’s metacarpophalangeal (MP) joint is usually held in hyperextension.
Pathophysiology
- Campyodactyly can arise from absent extensor tendon function, skin contracture, volar plate anomalies, and articular incontruity.8
- It is a congenital deformity of the PIP joint.2 Camptodactyly may be sporadic or familial. When it is familial, it follows an autosomal dominant pattern of inherentance.5
- Camptodactyly has been associated with ≥70 syndromes2 including Trisomy 123, oculodentodigital syndrome, orofaciodigital syndrome, and Aarskog’s syndrome.11
- Camptodactyly may be congenital (type I), acquired (type II), or syndromic (type III).10 Type II camptodactyly is often observed in girls between the ages of 7 and 11.
Instructions
- Camptodactyly is diagnosed by OBSERVATION. This diagnosis is confirmed by completing a history, physical examination and by performing imaging studies if appropriate but careful observation is the basis of the camptodactyly diagnosis.
- The characteristic lesion is a flexion contracture of the proximal interphalangeal joint5
- It almost always affects the little finger1,2,5
- It is typically painless1
- Sensory or motor deficits are usually not associated with camptodactyly1
- There is normal capillary refill of the affected digit1
- Swelling, erythema, and warmth are not associated with camptodactyly (ie., it is not associated with infection)1
- Camptodactyly is not associated with trauma9
Variations5
- The degree of flexion may vary from a very slight deformity to an almost right-angled bend; it is seldom more than this
- The fourth to second fingers, in decreasing order of frequency, may be affected similarly
- The extent of the deformity is progressively less in the more radial fingers
- Often there is hyperextension of the metacarpophalangeal joints of the affected fingers
- Occasionally the proximal interphalangeal joints of some fingers are also hyperextended
- Rarely there is flexion deformity of the terminal interphalangeal joints as well
- Involvement of the thumb is unusual
- In advanced cases, there is ulnar deviation of the affected fingers, with radial rotation of the fifth finger, and the palm becomes cup-shaped
Related Signs and Tests
- Fingers can be bent at the PIP joint due to a variety of diseases, disorders, and conditions, including Kirners deformity1, Dupuytren’s disease,2 injury,3 and rheumatoid arthritis4
Diagnostic Performance Characteristics
- The findings of the history and physical define the condition. Therefore, a condition that meets the criteria described in the “Instructions” section, by definition, has a sensitivity (true positive rate; proportion of actual positives that are correctly identified as such) and specificity (true negative rate; proportion of actual negatives that are correctly identified as such) of 100%
- The ability of individual clinicians to apply these criteria will alter the sensitivity and specificity of this diagnostic exam