gms | German Medical Science

Objectives/Interrogation: Phalangeal fractures are among the most frequent fractures of the skeleton. Lesions at the proximal phalanx are considered challenging because of the complexity of the anatomy in the region. The extensor tendon is a delicate structure that at the distal portion of the proximal phalanx spreads like a sheet, surrounding the bone surface with close contact.

Commonly seen in children and seldom in adults, fractures of the phalanx neck occur mostly at the proximal phalanx of the thumb and at the medial phalanx of the long fingers in adult patients. In nearly all cases described, the fracture shows dorsal displacement and is treated with K-wires fixation.

In the only study that specifically described proximal phalangeal neck fractures, Al Qattan reported on ten patients treated with non-displaced or dorsally-displaced fractures. In addition, that author employed the same classification to differentiate phalangeal fractures in adults and children, but it has neither mention of soft-tissue injury (extensor tendon injury) nor direction of fracture displacement.

There are no previous publications describing the treatment of choice for proximal phalangeal neck fractures with volar displacement.

Methods: We described the lesion and the treatment of two patients with proximal phalangeal neck fractures and severe volar displacement. We highlight that this type of deformity can cause a boutonniere-like lesion of the extensor tendon, with the distal stump of the central extensor tendon trapped at the fracture site (Figure 1 [Fig. 1]).

We propose an open reduction and internal fixation of the fracture with two 1.5-mm interfragmentary screws.

Results and Conclusions: We propose to add a division in the classification of Al Qattan for type II fractures in adults (displaced and with bone contact), in which IIA fractures show dorsal displacement (more common), and IIB fractures have palmar displacement (rarer and unstable).