Kirner’s deformity: progressiveness and classification

Abstract

In a 30-year-old man, bilateral Kirner's deformity has been diagnosed. In the fully extended finger, the long axes of the middle and terminal phalanges formed an angle of 10 degrees in the volar and 5 degrees in the radial direction. Owing to the altered morphology of the distal phalanx, its palmar surface was at an angle of 25 degrees to the long axis of the middle phalanx. The deformity has existed since birth and has not changed except in size. His mother had the same bilateral deformity. Other closer relatives showed a unilateral appearance of Kirner's deformity: his maternal grandmother and an uncle had in their right little finger and an aunt had in her left little finger. Although some authors reported that Kirner's deformity was progressive, the description only referred to a change in the deformity. Kirner's deformity may be classified according to its period of onset, i.e., a more frequently occurring early type and a late type of onset (with lower incidence) exists. Moreover, it can be further classified by typical morphologic changes as well as the family history of the affected person.

Reverse Kirner's Deformity: Case Report

“…4,7,19,20 A classification system recently proposed is based on age at onset and suggests that late-onset cases are more likely to be sporadic, with no family history. 21 The deformity in these cases takes between 3 months and 3 years to develop. In our case, the deformity was present at birth.…”

Camptodactyly and Kirner's Deformity in one Family

“…They both may be sporadic or familial 1,2,5,6,8 . In inherited forms of Kirner's deformity, it is an independent anomaly, but it can also occur as a minor part of different syndromes such as Down syndrome, pes cavus, osteomyelitis, and progressive myositis ossificans .…”

“…Kirner's deformity and camptodactyly have been regarded as independent congenital hand deformities [1][2][3] . They both may be sporadic or familial 1,2,5,6,8 .…”

“…Kirner's deformity is suggested to be inherited in an autosomal dominant trait with incomplete penetrance but sporadic cases were also reported. No specific genetic linkage has been identified 1,2,4 . Camptodactyly is a non-traumatic flexion contracture of the proximal interphalangeal (PIP) joints of one or more fingers, resulting in a permanent volar inclination of the affected digits.…”

“…Kirner's deformity and camptodactyly are rare and usually bilaterally occurring congenital hand deformities [1][2][3] . Kirner's deformity is characterized by palmar and radial deviation of the distal phalanx of the little finger with a varying degree of rotation and a small, dysmorphic watch-glass nail associated with swelling of the distal interphalangeal (DIP) joint.…”