Multipin clamp and rod attachment

#The present invention relates to a traumatologic device, and, more particularly, to an improved traumatologic device for reducing long-bone fractures that require external fixation.

#A variety of traumatologic devices for reduction of bone segments are known in the art. For example external bone fixation devices (commonly referred to as external fixators) are known. Typically external fixators are used to reduce fractures of the long bones in the human body. These devices are always placed in position under anesthesia. In order to reduce the duration of the anesthesia, fixator devices have been developed to allow positioning at every possible angle, while still allowing easy adjustment by a surgeon.

#The early development of external fixator devices, such as that exemplified by U.S. Pat. No. 2,250,417 to Ettinger, was aimed at producing a simple and lightweight fracture reduction device which is practical to leave in place to serve as a retention device, thereby rendering a cast unnecessary. As disclosed, the Ettinger device allows two separate sets of dual bone pins or screws, each transcutaneously installed in the bone on either side of a fracture, to be connected and fixed at variable points to a single bone fixation rod running roughly parallel to the longitudinal axis of the affected bone. This resultant connection of opposing pin/screw sets provides the immobilization necessary to allow proper healing of the fracture. Ettinger discloses the use of multiple sleeve and post connections between the bone pins/screws and the bone fixation rod to allow the bone pins or screws to be installed at varying angles relative to the bone fixation rod. Ettinger additionally discloses the use of a rod and sleeve configuration whereby one of the two bone pin/screw couplings is fixed to the bone fixation rod, while the second comprises an internally threaded sleeve that is threaded over the opposite end of the bone fixation rod, and whose position is adjustable relative to the fixed coupling via rotation of the bone fixation rod.

#The features and advantages of the present invention will become more readily apparent from the following detailed description of the invention in which like elements are labeled similarly and in which:

#FIGS. 1A, 1B and 1C are two exploded perspective views and an elevation view of a bone pin vise portion, a bone pin vise opposing plate and star grind cover, and a bone pin vise opposing plate incorporating triangular bone pin clamping grooves, respectively, of the bone pin locking assembly of the current invention;

#FIG. 2 is an exploded perspective view of a rod attachment portion of the bone pin locking assembly of the current invention;

#The traumatological device of the present invention is discussed herein with reference to a preferred embodiment adapted to be used in the consolidation and fixation of a fractured long bone. It is to be understood that the invention finds applicability for use in any circumstance in which it is desired to fix the orientation of bone segments on either side of a fracture.

#Referring more particularly to the drawings, FIG. 1A shows an exploded view of a bone pin vise portion. As shown in FIG. 1A, the bone pin vise portion 1 comprises first and second opposing plates 2 and 2′ with engaging faces 4 and 4′, and outside faces 6 and 6′. Each engaging face is characterized by a plurality of spaced parallel grooves 8 and 8′ which are cylindrically arcuate and which are in confronting relation to the spaced parallel grooves on the face of the opposite plate. The parallel grooves 8 and 8′ coordinate to receive the proximal ends of bone pins 28 (shown in FIG. 6) installed on one side of a fractured bone. When the pin vise portion is in the clamped condition, the bone pins 28 are nested in the respective grooves formed by the conjunction of parallel grooves 8 and 8′ (of engaging faces 4 and 4′). It will be understood that the number and shape of the grooves is not critical to the operation of the device.

#The opposing plates 2 and 2′ are connected by two vise bolts 12 and 12′ which operate to draw together engaging faces 4 and 4′ in order to grip the proximal ends of bone pins 28 which have been installed in a bone. Vise bolts 12 and 12′ are slideably accepted by corresponding bores 14 and 14′ in each end of first opposing plate 2, and are threadably accepted by threaded bores 16 and 16′ in each end of second opposing plate 2′. The internal threads of bores 16 and 16′ of second opposing plate 2′ correspond with the external threads of vise bolts 12 and 12′ such that a clockwise rotation of vise bolts 12 and 12′ acts to draw opposing plates 2 and 2′, and therefore engaging faces 4 and 4′, together. Further, first opposing plate 2 incorporates bolt head bearing surfaces 30 and 30′ to provide uniform bearing contact with the bottoms of the heads of pin vice bolts 12 and 12′. The vise bolts 12 and 12′ may be provided with washers 18 and 18′ positioned between the heads of the vice bolts 12 and 12′, and bolt head bearing surfaces 30 and 30′ of the pin vise portion opposing plate 2. The washers serve to reduce friction between the vise bolts and bolt head bearing surfaces, thereby easing final tightening of the vise bolts.