Field of Search:
128/92EC,92EA,92C,92CA,92R,83,346,303 81/111 269/90,203,205 294/106,116 403/52,86,91,100,102,316,317 3/1
Claims:
The following is claimed as invention
1. A prosthesis holder including a pair of opposing jaws adapted for grasping a prosthesis, a short and a long locking stud, one stud mounted on each jaw for angular motion therewith, a locking member carried on the long stud for selectively engaging the short stud and urging the short stud into angular superposition over the long stud, thereby simultaneously urging said holder jaws into their prosthesis grasping position and hinge means for mounting the jaws to one another so as to permit relative angular motion therebetween, said hinge means being located between said jaws and said locking member.
2. A prosthesis holder according to claim 1 wherein said holder jaws each include a cylindrical mounting collar member, the mounting member in cross section describing substantially a circular arc of substantially 180°, and a liner member having an inner face adapted to engage the prosthesis and an outer face adapted to securely engage the jaw mounting collar.
3. A prosthesis holder according to claim 1 wherein each liner member includes tip portions formed to overhang and engage said mounting collar member and at least one guide slot formed to engage a locating stop lug formed on said mounting collar member.
4. A locking mechanism for a prosthesis holder having a pair of hinged jaws for angular motion to and from a prosthetic grasping position; said locking device including a short and a long locking stud, one stud mounted on each jaw for angular motion therewith, and a locking member carried on the long stud for selectively engaging the short stud and urging the short stud into angular superposition over the long stud, thereby simultaneously urging said holder jaws into their prosthetic grasping position.
5. A locking device according to claim 4 wherein said locking member is threadedly attached to said long stud for axial motion therealong, motion of the locking member toward said jaws bringing the locking member into engagement with said short stud, and further lock member motion toward the jaws urging the short stud into progressively more exact angular superposition over the long stud.
6. A locking device according to claim 4 wherein said locking member is a locknut having a conical interior surface for engaging a terminal portion of at least the short locking stud.
7. A locking device according to claim 6 wherein said locking mechanism includes a jam nut threadedly attached to said long locking stud for jamming said locking member in a given location on said long locking stud.
Description:
DESCRIPTION OF THE INVENTION
This invention relates generally to surgical instruments and more particularly concerns devices for holding a prosthesis.
In surgery involving the installation or other manipulation of a prosthesis, devices for holding the prosthetic member have long been used as valuable operating aids. Such devices must firmly grasp the prosthesis, and must present it for easy installation into the patient.
A number of prosthesis holders have previously been offered to meet these general objectives. The Charnley device provides a pair of relatively centrally located prosthesis-holding jaws connected at a relatively distal hinge. Handles and locking devices having a protruding mechanism are located proximal to the prosthesis. This device offers considerable clamping force, but removal of the instrument after installation of the prosthesis is sometimes difficult, since the jaws must be opened a relatively large distance to free it from the emplaced prosthesis. Further, the direction in which the holder must be removed from the prosthesis often makes removal difficult, since the device must be maneuvered upward over the prosthesis.
The Bechtol device grasps the prosthesis relatively distally and provides a locking device and handles located relatively centrally, and a jaw hinge located relatively proximally. While the holder may be more easily removed from the emplaced prosthesis, less grasping or clamping force is provided.
Both devices provide a locking mechanism actuating knob located at either a right or a left side of the instrument. While this knob location may be convenient for operations performed upon one side of the patient, the knob is almost inevitably obstructed when operation is to be performed upon the opposite side of the anatomy.
It is therefore the general object of the present invention to provide a prosthesis holder which firmly grasps a prosthesis, yet which can be easily and quickly removed from the emplaced prosthesis with a minimum of motion and effort by the surgeon.
It is a more specific object to provide a prosthesis holder wherein prosthesis gripping force is not sacrificed for ease of holder removal.
Another object is to provide a prosthesis holder wherein the locking device actuator does not become obstructed by reason of its location on the holder. A related object is to provide a holder having a jaw locking device which can be operated with either hand and with equal facility by the using surgeon. An associated object is to provide a holder having a locking device which is operable with a simple rotative motion of the thumb and forefinger.
It is yet another object of the invention to provide a prosthesis holder having interchangeable prosthesis-gripping jaw liners which can be removed and reattached quickly, easily, and without the use of tools.
It is still another object of the invention to provide a prosthesis holder which serves to protect the finely finished articulating surface of the prosthesis head.
It is a further object to provide a prosthesis holder having a locking device which urges the jaws into their prosthesis-gripping position with relatively great force. An associated object is to provide a locking device which permits the jaws to be conveniently opened through a wide angle.
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of the prosthesis holder showing a typical prosthesis in phantom outline;
FIG. 2 is an elevational view of the prosthesis holder in partial longitudinal section showing in detail the arrangement of gripping jaws, jaw liners, jaw locking devices and jaw hinge;
FIG. 3 is a sectional view taken substantially in the plane of line 3--3 in FIG. 2 and showing in further detail the prosthesis holder jaws, jaw liners, locking device and hinge;
FIG. 4 is a sectional view taken substantially in the plane of line 4--4 in FIG. 2 and showing in yet further detail the gripping jaws and jaw hinge;
FIG. 5 is an exploded plan view of a portion of the holder showing the jaws in an open position and the jaw liners removed therefrom;
FIG. 6 is a sectional view taken substantially in the plan of line 6--6 in FIG. 3 and showing in further detail the attachment of the jaw liners to the jaws;
FIG. 7 is a sectional view taken substantially in the plan of line 6--6 in FIG. 3 showing a modified form of the jaw liners; and
FIG. 8 is a sectional view taken substantially in the plan of line 8--8 in FIG. 7 and showing in further detail the modified form of jaw liner.
DESCRIPTION
While the invention will be described in connection with a preferred embodiment, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention.
Turning first to FIG. 1 and 2, there is shown prosthesis holder 10 grasping a prosthesis 11. Speaking generally, the holder 10 includes a pair of jaws 12 and 13 inter-connected for relative angular motion by a hinge pin 14, to grasp the prosthesis 11 in a pinching or plier-like manner. The jaws 12 and 13 may be locked in their prosthesis-grasping position by a novel jaw locking mechanism 15. The holder is conveniently grasped and manipulated by means of a handle 16 which may be surfaced in any convenient manner, as by knurls 17.
As previously indicated, it is important that a prosthesis holder grasp the prosthesis 11 firmly, yet be easily and quickly removable from the installed prosthesis with a minimum of jaw motion. In accordance with one aspect of the invention, therefore, jaws 12 and 13 are hinged for relative angular motion about the hinged pin 14 at a point located between the jaws and the locking means.
As also indicated, utility of a prosthesis holder is enhanced if the holder jaw locking device can be easily and quickly operated from either side of the device by either hand. In accordance with this aspect of the invention, therefore, the locking device 15 includes a short locking stud 20 mounted on or formed integral with one jaw 13, and a long locking stud 21 mounted on or formed integral with the opposite grasping jaw 12. It will be noted that the studs 20 and 21, thus arranged, undergo the same angular motion as the jaws 12 and 13 when the jaws 12 and 13 are opened or closed.
The long locking stud 21 is provided with a threaded extension 23 which is secured to the handle 16 in the illustrated device. Also carried upon the threaded extension 23 is a locking member 25 or nut, which can be quickly and easily moved along the axis of the long locking stud 21 for engagement with the short locking stud 20. Here, this axial motion is produced simply by rotating the locking nut 25, since the nut is internally threaded for engagement with the threaded extension 23. Progressive motion of the lock nut 25 toward the jaws causes an internal conical surface 26 to engage a terminal portion 27 of the short locking stud 20 and to urge the short stud 20 into a progressively more exact angular superimposition over the long locking stud 21 in the position illustrated in FIG. 3. This stud motion toward the described superimposed position correspondingly urges the jaws 12 and 13 into their prosthesis-gripping positions.
In the illustrated embodiment, the lock nut 25 also engages a terminal portion 28 of the long locking stud shank 29. Those skilled in the art will understand that, by decreasing the altitude of the internal conical surface configuration, less axial motion of the lock nut 25 will be required to bring the lock nut into firm lock engagement with the locking studs. Conversely, a greater conical altitude will require relatively greater motion of the nut to engage or disengage the locking studs.
To secure the lock nut in a given location, whether locked or unlocked, along the long locking stud, a jam nut 30 can also be carried upon the threaded extension 23.
In accordance with another aspect of the invention, the internal prosthesis-grasping surface of the jaws 12 and 13 can be easily and quickly altered to accommodate various prosthesis shapes. To this end, each holder jaw 12 and 13 is provided with a removable liner 32 and 33, which can be replaced with a liner of alternate internal configuration. In the illustrated embodiment, the liners 32 and 33 are carried on the jaws 12 and 13 by respective mounting collar portions 34 and 35 which take the form of circular arcs of substantially 180°. Each liner member 32 and 33 is provided with an inner face 36 and 37 adapted to engage the prosthesis 11, and an outer arcuate face 38 and 39 adapted to securely engage the jaw mounting collars 34 and 35. To further orient the liners to the jaws, the liners 32 and 33 are each additionally provided with upper and lower lip portions 43, 44, 45 and 46 formed to engage the edges of the respective mounting collar members 34 and 35, and guide slots 49 and 50 formed to engage collar member locating stops 51 and 52. As illustrated in FIGS. 7 and 8, the internal surfaces 36 and 37 of the liners 32 and 33 can be formed in any of a variety of shapes to provide a good grasp of the associated prosthesis 11 and to assist in its accurate positioning relative to the prosthesis holder 10 itself.
Thus designed, the prosthesis holder can be deftly used. Assisting surgical personnel, who have been informed of the type prosthesis to be involved in the operation, install appropriate jaw liners 32 and 33 upon the jaws 12 and 13 by sliding the liners 32 and 33 over the mounting collars 34 and 35 with an arcuate twisting motion. The jaws are then opened, the prosthesis inserted, and the jaws closed from the position shown in FIG. 5 to that shown in FIG. 3. The lock nut 25 is next moved down the long locking stud 21 into engagement with the short locking stud 20 by a rotating motion of the thumb and forefinger of either hand. When the jaws have been firmly locked about the prosthesis, the lock nut 25 can be secured in place by rotating the jam nut 30 into contact therewith. The held prosthesis can then be confidently and easily manipulated and moved during subsequent surgical operations. When the prosthesis has been emplaced in the patient, the holder is removed by loosening and moving away the jaw nut 30, the lock nut 25, and by opening the jaws. If necessary the jaws can be opened with a finger motion urging the short locking stud 20 in the direction of the arrow shown in FIG. 5. When the jaws are opened, the prosthesis holder 10 can be removed from the prosthesis 11.