Fixed angle dual prong pin fixation system

Abstract

A bone fixation system and method are provided. The system includes a dual prong pin and a bone screw. The pin is especially configured and contoured to fixate fractures of the proximal phalanx, especially hyperextension fractures. Fracture of other long bones of the hand, foot or elsewhere may be managed with this bone fixation system.

Description

CROSS REFERENCES TO RELATED APPLICATIONS[0001]This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 61 / 086,822, filed on Aug. 7, 2008, the complete disclosure of which is incorporated herein by reference in its entirety.FIELD OF THE INVENTION[0002]A bone fixation system and method suitable, for example, for fracture fixation of the proximal phalanx of the hand or foot, especially of the hyperextension type, are provided. The system is also suitable for fixating fractures of other long bones of the hand, such as the middle phalanx or the metacarpals, and of the metatarsals in the foot. The system is also suitable for fixating fractures in other bones outside of the hand or foot.INTRODUCTION[0003]Hyperextension fractures of the proximal phalanx are typically problematic, especially in the elderly, because such fractures are very difficult to stabilize. Current techniques and devices can often lead to very significant functional impairment and ...

AI Technical Summary

Benefits of technology

[0011]In an illustrated embodiment, the two prong device has a single locking domain to which a single bone screw may be mated. In another embodiment, the dual prong pin may have two locking domains to which two bones screw may be mated. More complex configurations can be devised for accommodating more than one screw or to provide an additional buttress in between the locking domains to provide additional fixation and buttress support.

[0012]In another embodiment, the two prong pin has a retaining feature configuration located on the distal portion of the prongs. This retaining configuration can take the form of raised rings or protrusions or barbs on the shank of the prongs. These configuration variations help increase the gripping power of the prongs, thus preventing separation of the fracture.

Problems solved by technology

Hyperextension fractures of the proximal phalanx are typically problematic, especially in the elderly, because such fractures are very difficult to stabilize.

Current techniques and devices can often lead to very significant functional impairment and disability.

These hyperextension fractures of the proximal phalanx usually result in less optimal outcomes than fractures of larger bones such as the distal radius.

Despite their versatility, pins have limitations especially with fractures that have a significant amount of fragmentation (comminution) of the bone at the fracture site or when the fractured bone is too soft resulting in premature loosening of the pins.

However, use of plates usually results in scaring which frequently limits the proper gliding motion of the surrounding tendons, especially the extensor tendon.

This approach often results in a large scar in the most visible part of the hand (not readily received by most female patients).

In the presence of significant comminution and osteoporosis, as is often the case scenario in the elderly female population with these fractures, plate fixation of hyperextension fractures of the proximal phalanx is usually not able to hold the alignment of the fracture because the plate has limited mechanical ability to buttress these fractures and loss of reduction is often frequent after plate fixation.

In addition, conventional plating of the long bones of the hand frequently results in malalignment of the involved bone after the plate is applied; the operated finger will tend to abnormally scissor or overlap onto an adjacent finger.

Thus, plating requires absolute precision because even a small amount of angular malalignment is not well tolerated.

However, the nail and sleeve configuration is not much different from pins and has limited ability to control hyperextension fractures of the proximal phalanx which frequently results in loss of fracture reduction.

In addition, a significant portion of the hardware is prominent outside of the bone, irritating the tendons.

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