Stress radiography positioner

A knee positioning device for applying stress to a knee joint during a radiographic procedure. The device comprises at least one sectional support board having a plurality of slots therein, a plurality of holding members positioned within the slots, wherein each holding member is configured to support a positioning structure.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to devices for applying stress to joints and, more particularly, to a knee stress radiography device used to place stress on a knee joint in a desired position, particularly when an X-ray image of a knee is taken.

2. Description of Related Art

Certain diagnostic X-ray examinations of the knee can be made only when the knee is held in a specific position. In order to accurately perform stress radiography of the knee and other joints, applying stress to the knee is required. This requires a person to hold the patient's leg and apply stress to the knee joint, which causes this person to be in close proximity to the X-ray beam. Further, when the person is holding the patient's leg, the stress applied to the knee at one particular time may not be the same stress applied to the knee at a different time, thereby making it difficult to perform reproducible stress radiography of the knee.

A device for holding a patient's leg for stress radiography has been described in U.S. Pat. No. 4,232,681. This device is a leg positioning device for X-ray filming that has a support with which the leg can be fixedly held at two-spaced locations, a pressure element that can apply incremental variable pressure to the leg intermediate these locations and a device for measuring the applied pressure so that the same can be exactly reproduced whenever desired.

However, this prior art device and others similar to this device are bulky, expensive and do not adjust to fit all body sizes or adjust to apply pressure to the knee at multiple locations and, therefore, may not be used each and every time by a physician. Therefore, it is desirable to provide a stress radiography device that is inexpensive, lightweight, adjustable for all body sizes and positions, and easy to assemble in order for a physician to accurately and reproducibly perform stress radiography of the knee and other joints while remaining safely outside the X-ray beam.

SUMMARY OF THE INVENTION

The present invention provides for a knee positioning device for applying stress to a knee joint during a radiographic procedure. The device comprises at least one sectional support board having a plurality of slots therein, a plurality of holding members positioned within the slots, wherein each holding member is configured to support a positioning structure.

DETAILED DESCRIPTION OF THE INVENTION

An exemplary embodiment of the present invention provides for a device10for applying stress to a knee during a radiographic procedure as shown inFIGS. 1-10. The components of the device10include at least one sectional support board12(preferably two board sections12A and12B) having a plurality of spaced apart holes or slots14therein, and a plurality of holding members16such as pins or pegs adapted to be inserted into the holes14in order to support leg positioning structures S (discussed later) that are placed on the assembled support board sections12A and12B.

Referring toFIG. 2, the board section12A has one end18that includes a semi-circular opening20therein and board section12B has a corresponding end22that includes a semi-circular bar or pin24that is slidably received within the opening20of board end18such that board sections12A and12B are linearly and releasably attached to each other. The device10may also include a plurality of planar sectional boards12, wherein each board section has both a semi-circular opening20on one end and a semi-circular bar24on another end (not shown) such that a plurality of board sections may be attached to each other in order to accommodate larger size individuals. For example, the prior art devices are sized to accommodate both the small youth size and the largest adult size, thus making these devices very large and bulky. In contrast, the board sections12A and12B of device10may be sized to accommodate small to average sized individuals such that the assembled support board12is smaller and less bulky than the prior art frame or board. The advantage of device10is that additional planar board sections may be added on to accommodate large adult sized persons. Attachment of the support boards12to each other may be accomplished by any other manner known in the art such as the use of mechanical fasteners, for example, clamps hinge-pin arrangement or other means such as a snap-fit arrangement. The board sections12A and12B may be rectangular shaped and may be made of a lightweight material such as wood, plastic or a lightweight metal.

FIG. 3shows a plurality of holding members16inserted into the holes14of the support board12. The holes14in the sectional support board12may also be elongated slots adapted to receive the holding members16, wherein the holding members16are slidably moved along a longitudinal axis of the slots as shown inFIG. 11. The holding member16includes a first section28, a second section30and an annular flange32defined therebetween. As shown inFIGS. 3 and 4, the first section28is inserted into the holes14and the annular flange32abuts against the board12such that the second section30extends upwardly therefrom. The holding members16are placed in a desired position for placement of the positioning structures S.

Referring toFIGS. 4-10, each of the positioning structures S of the device10includes an opening (not shown) for receiving the second section30of the holding members16, thus securing the structure S to the sectional board12. The positioning structures S may include, but are not limited to, femoral and/or tibial stabilizing pads40and40′, which are spaced apart and attached to opposite ends of the sectional board12(FIG. 4), a force producing device52attached to a side part of the sectional board12(FIG. 5), a foot support44secured to a front part of the sectional board12(FIGS. 6 and 7) and an angled knee pad46positioned adjacent the force producing device52and attached to a center part of the sectional board12(FIG. 8). As shown inFIGS. 5-10, the force producing device52may be as simple as a support frame42having an end E attached to the support board12and a knee pad screw assembly50attached to the support frame42. The assembly50may include a base plate60having a pad62attached thereto and a threaded member64extending laterally therefrom, wherein a knob48is attached to the member64such that rotation of the knob48causes the pad62to advance or retract, thus forming the force producing device52. The force producing device52may also be any device known in the art for applying desired force or pressure such as, but not limited to, a spring-loaded type device, a plunger-type device with a stop or a tension band. A dial gauge G as shown inFIG. 10, which can be a digital (e.g., LED display) or an analog display, may also be attached to the force producing device52to indicate the pressure being applied. It is advantageous that the gauge G is of a type known in the art, such as a drag-type pointer, i.e., a pointer which remains in an indicating position even after the pressure has been removed so that the indicated value remains visible. Such pointers are readily released by, for example, depressing a button. Alternatively, an indicator light may also be used to indicate when the desired pressure is applied. Each of these positioning structures S can be located at various positions on the sectional board12depending on the body size of the patient's leg. Further, not all of the above-described positioning structures S need to be used during a radiographic procedure. For example, three positioning structures S may be used such as a foot support44, a force producing device52and a pad40opposite the force producing device52so long as these structures S can hold the patient's leg and place adequate stress on the knee joint being X-rayed.

Additional positioning structures S may be used at various positions on the board12in order for a physician to apply stress on the leg at one or more desired locations. For example, either one or more force producing devices52or other positioning structures S may be used to apply a varus, valgus, anterior, or posterior directed pressure to the knee or other joint of a patient during a radiographic procedure. Each of the positioning structures S, including the holding members16and sectional board12, can be coated with a bactericidal material, such as a Microban coated vinyl, for hygienic purposes.

In operation as shown inFIG. 9, a patient's leg is placed into the device10so that the knee region is supported by the foot support44which affixes the foot due to the engagement of the foot with the foot support44. The back of the knee is placed on the angled pad46and the thigh and ankles are supported on one side by the stabilizing pads40,40′, respectively. Pressure is exerted on the knee joint by the force producing device52wherein the leg is stabilized in its desired position. The leg and foot can be held in any necessary position because of the ability to add additional board sections and the ability to place any positioning structure S at any location on the sectional board12.

FIG. 11shows a second embodiment of a device10′ for applying stress to a knee that is somewhat similar to device10except for the differences noted below. Like reference numerals are used for like parts. The device10′ includes a base board70having a plurality of slots72therein, adjustable holding members16′ for engagement with the slots72and positioning structures S′ supported on the holding members16′. The holding members16′ may be of any type known in the art, such as a nut and bolt arrangement or clamp arrangement, so long as the holding member16′ can be slidably moved along the slot axis thereby providing the capability to adjust or move the positioning structures S′ to a desired position on the base board70. The positioning structure S′ of device10′ may include a foot support44′, a force producing device52′ and a ruler74for measuring the position of a patient's leg. Here, the foot support44′ uses a boot that can support both the foot and ankle thus eliminating the stabilizing pads40,40′ as in device10. Further, the force producing device52′ is similar to the force producing device52and includes a support frame42′, a pad62′ attached to a member64′ extending laterally therefrom, wherein a knob48′ is attached to the member64′ for advancing and retracting the pad. The positioning structure S′ as shown inFIG. 11may be used interchangeably with the corresponding positioning structure S shown inFIGS. 5-10. Adapting the holding members16and16′ to support any of the positioning structures S and S′ is also well known in the art.