CLINICAL ANATOMY OF TRAUMATIC DEFORMITIES OF FINGERS EXTENSOR APONEUROSIS

Abstract

The main traumatic deformities of the extensor expansion (EE) are the boutonnière lesion (BL) and the mallet finger (MF). The classical BL is characterized by flexion deformity at the proximal interphalangeal joint, with hyperextension of the metacarpophalangeal and terminal interphalangeal joint, caused by the rupture or division of the central slip of the EE in a finger. The MF is defined as a deformity resulting from loss of EE continuity to the distal finger joint. We analyzed the frequency of location for the two hands and for fingers II–V, on 2 consecutive series of 100 cases each. We noticed a slight predominance in the right hand fingers for both types of lesions: 54% for BL, and 57% for MF. Location of BL was as follows: 8% index finger (II); 42% middle finger (III); 29% ring finger (IV) and 21% little finger (V). There was no multidigital involvement in cases of traumatic BL. Location of MF was as follows: 34% index finger (II); 23% middle finger (III); 17% ring finger (IV) and 26% little finger (V). In three clinical cases there were two fingers involved (fingers IV and V). Traumatic lesions of the EE are more frequent in the dominant hand. The BL involve most often the fingers II and III (index and middle fingers), and MF lesions are more often located in fingers III and IV (middle and ring fingers). (Supported by CNMP 62054/2008).