Clinodactyly, Camptodactyly, Kirner's Deformity, and Other Crooked Fingers

Curvature of the fingers is fairly common. While it is frequently seen without associated abnormality, it has been noted in conjunction with other pathological conditions often enough that its presence should alert the physician to their possibility. Since the lesion is usually asymptomatic, it is mentioned only briefly in radiologic textbooks. A book on congenital hand anomalies (2) shows crooked fingers in a variety of hand anomalies, but mentions no associated abnormalities. The purpose of this communication is to describe the various types of curved fingers and the conditions with which they are related, as well as the significant associated findings which may aid in a specific diagnosis. The study is based on a review of clinical material from the Henry Ford Hospital in Detroit and the University Hospital in Ann Arbor, as well as a review of the literature. The presence of curved fingers has been appreciated in the medical literature for many years. In an article on mongolism, Smith in 1896 (68) published the first roentgenogram illustrating clinodactyly. We1ch (72) quotes Tamplin who in 1846 described camptodactyly as an entity distinct from Dupuytren's contracture. Clinodactyly and camptodactyly were noted by some of the great masters and depicted in their art. Bruno (7) shows illustrations of camptodactyly by Botticelli and da Vinci. The presently used terminology for crooked fingers was defined between 1910 and 1930 (26,27,54). There has been much confusion in the use of the terms clinodactyly and camp-todactyly. Some authors use them contrary to their common usage and may show an illustration of camptodactyly while labeling it clinodactyly (43). Others use the terms interchangeably. Dutta (11) traces the historical background of the usage of these terms. The following terminology will be used in this text. Terminology Clinodactyly (Gr. klinein to bend + daktylos finger) (11, 28) refers to a curvature of a finger in a mediolateral plane. It may be radial or ulnar in direction and may involve any finger. It usually refers to a radial deviation of the fifth finger at the distal interphalangeal joint and is most often associated with a short middle phalanx which is shorter on its radial than ulnar side (Fig. 1). Some authors (27) use the term clinodactyly in reference to the fifth finger only. In this paper the term will be used in its more general sense. When the fifth finger is referred to, it will be called clinodactyly 5. Camptodactyly (1, 8, 26, 67, 70, 72) (Gr. kamptos bent + daktylos finger) denotes a permanent flexion of one or more of the fingers. The deformity is located at the proximal interphalangeal joint and also usually involves the fifth finger (Fig. 2). Its cause is not known. The condition is probably related to a fascial abnormality (8, 70) but may be related to contracture of the flexor digi-torum sublimis (67).