Surgery – Instruments – Sutureless closure
Reexamination Certificate
1999-12-22
2001-05-29
Mancene, Gene (Department: 3732)
Surgery
Instruments
Sutureless closure
Reexamination Certificate
active
06238417
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates generally to surgical devices for fixation of two or more segments of tissue, and more particularly to a fixation device useful for securing two or more segments of bone in a desired spatial relation.
The use of both internal and external fixation devices to prevent major movement between two or more sections of bone is well known in the art. External casts and braces have commonly been employed to prevent movement between larger bone segments, and have been particularly useful in the fixation of long bone fractures in the extremities. For small bone segments and bones within the trunk of the body which may not be readily immobilized by braces and casts; plates, screws, nails, and wires have been implanted to maintain the relative position of these bones during the healing process. In some instances, a single screw with a uniform shaft is screwed between two bone segments to maintain these in place. Alternatively, a pinning device such as a nail may be driven into both of the bone segments to create fixation. In other applications, a lag screw is utilized with a first threaded portion passed through a first bone segment and threaded into a second segment of bone. A nut is then threaded onto a second machine threaded portion of the lag screw to reduce the fracture between the two bone fragments. Alternatively, a similar type of lag screw may be utilized in conjunction with a plate. Each of a series of lag screws is inserted into bone fragments and a plate is attached across the machine threaded portion of the lag screw. A nut is threaded onto each screw thereby attaching the plate to the bone and maintaining the spatial relationship of the bone fragments.
For smaller bones and bone fragments, small wires, commonly known as Kirschner wires (K-wires), have been inserted into the bone to immobilize the fragments. After the wires are inserted, the proximal section of the wire is cut to the desired length. While these devices have been generally successful, at least initially, in accomplishing the desired immobilization, there are a number of problems which have been encountered with their use. Specifically, it has been found that in some instances, the fixation wire can migrate from the point of its initial insertion leading to loss of fracture fixation or damage to surrounding bodily structures, such as nerves or blood vessels adjacent the entry or exit site of the wire. Moreover, cutting the wire can result in a wire end that may be sharp, leading to possible tissue irritation adjacent the wire. In an effort to limit migration of the wire, the cut end may be bent over or left protruding from the skin, also leading to possible tissue irritation and/or infection. Additionally, if the wire is trimmed too close to the bone and the wire migrates inward, the end could be lost well within the bone surface, making it impossible to retrieve without damaging the surrounding bone structure. Thus, there remains a need for an orthopedic fixation device having the beneficial affects of the above-referenced devices but offering ease of insertion, patient comfort after insertion, reduced chances for infection, and the ability to withdraw the device after a desired time period.
SUMMARY OF THE INVENTION
The present invention relates to an adjustable length fixation device comprising an elongated shaft and a head fixable to the shaft. The head includes an internal channel with an engaging portion movable between a first position and a second position. When the engaging portion is in the first position, the internal channel defines a first configuration adapted to slidingly receive the elongated shaft. When the engageable portion is in a second position, the internal channel defines a second configuration adapted to prevent movement of the head along the elongated shaft.
The present invention also contemplates a method for fixing two tissue segments. The method comprises providing an elongated shaft having a proximal end and a distal end, and a head having a channel for slidably receiving the elongated shaft. The elongated shaft distal end is inserted through a first tissue segment and into a second tissue segment. The head is positioned about the proximal end of the shaft and slidingly advanced along the shaft toward its distal end. The head is positioned adjacent the first tissue segment and locked to the shaft.
An apparatus according to the present invention further contemplates an instrument for removing a head from an adjustable length fixation device. The removal instrument comprises an outer member having a longitudinal axis and defining a longitudinally extending internal channel. The internal channel includes an anvil surface. An inner tube is sized to be received within the internal channel and includes a longitudinally extending cutting blade. The blade is disposed adjacent the anvil and upon rotation of the inner member in relation to the outer member, the blade is urged toward the anvil to cut a head disposed between the blade and anvil.
The present invention further contemplates an orthopedic fixation system including a plate in combination with an adjustable length fixation device according to the present invention. A fixation plate having at least one aperture, may be placed along the tissue to be fixed. An elongated shaft may extend through the aperture in the plate and into the tissue to be fixed. A head having an outer surface for engagement with the plate and an internal channel, is positioned on the shaft with the shaft extending through the internal channel. The head may then slide along the shaft until it engages the plate and is fixed in position to engage the plate and the shaft. In one preferred embodiment, the head includes a series of external threads to mate with a similar internal thread pattern in the plate. In another preferred embodiment, the aperture of the plate includes at least a partially spheroidal surface which is engaged by a corresponding surface on the head to permit non-perpendicular orientation of the shaft with respect to the plate.
One object of the present invention is to provide an adjustable fixation device. Another object of the present invention is to provide a K-wire fixation device with a head slidable along the shaft. A further object of the present invention is to provide a method for fixation of two or more bone segments with an elongated shaft and an adjustable head. Yet a further object of the invention is to provide a plate and adjustable length fixation device, the fixation device having angular freedom of movement with respect to an opening in the plate. Still a further object is the provision of an instrument to remove a head locked to a shaft according to the present invention. These and other objects of the present invention will become apparent to those skilled in the art, based on the following description.
REFERENCES:
patent: 2398915 (1946-04-01), Bell
patent: 2485531 (1949-10-01), Dzus et al.
patent: 4456005 (1984-06-01), Lichty
patent: 4640271 (1987-02-01), Lower
patent: 4688561 (1987-08-01), Reese
patent: 4796612 (1989-01-01), Reese
patent: 4869242 (1989-09-01), Galluzzo
patent: 4940467 (1990-07-01), Tronzo
patent: 4976712 (1990-12-01), VanderSlik
Mancene Gene
Robert Eduardo C.
Woodard Emhardt Naughton Moriarty & McNett
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