Patent Application
20060174895
Orthopedic procedures often require precise anatomical positioning. For instance, certain spinal surgical procedures require a fixed, known positioning of the spinal column. Surgeons often strive to place a patient's anatomy, such as the neck or back in a neutral position (e.g., having an appropriate lordosis or kyphosis) for better access during surgery and/or to place surgical devices or implants. Crude implements such as inflatable pads, saline bags, or rolled-up sections of material are sometimes used in an effort to accomplish this task.
Other diagnostic and pre-operation procedures may also require a known anatomical positioning. Imaging procedures such as X-Ray, CT or MR imaging provide invaluable information and are often used as a reference during surgical procedures. Positioning markers that appear in the resultant images are sometimes used to help identify reference points. However, the position of these markers as well as the position of the patient's anatomy should be repeatably established for maximum reliability. The locating markers are more accurate if the anatomical position is the same as when the images were taken. The relevant anatomy should also be stabilized and near-motionless during imaging process to enhance the resultant image quality.
Further, the relatively recent introduction of motion sparing devices as spinal implants entails a greater degree of positional precision as compared to that needed for fusion technology. Thus, the need for repeatable, accurate anatomical positioning has become even more crucial.
Accordingly, some effort has been made to use a positioning device to capture a desired anatomical position prior to surgery, perhaps during a consultation visit, and then transfer that position to the operating room table for surgery. However, it is often difficult for surgeons to accomplish this feat because of the bulkiness and lack of repeatable accuracy and adjustability found in conventional devices.
Embodiments of the present invention are directed to orthopedic positioning devices adapted to capture or register a desired anatomical position. Numerous embodiments are provided, each employing various mechanisms for capturing the desired anatomical position. Embodiments may include a plurality of independently deformable members or one or more support members forming a contact area adapted to contact the body and conform to the anatomical position when placed in contact with the body. One or more adjustment members may be used to permit alteration of the contact area either to conform to a neutral anatomical position or to set a desired anatomical position. A locking mechanism may further be included to lock the adjustment members to retain the shape of the contact area after the body is removed from the contact area.
The present invention is directed to embodiments of orthopedic devices and methods adapted to capture and retain a desired anatomical position. As a non-limiting example, the lordotic curvatures designated LC1 (cervical) and LC2 (lumbar) in
In any case, the present embodiments and methods of using said embodiments are well suited for establishing and repeatably determining an appropriate vertebral spacing and alignment. The devices disclosed herein may also be suitable for capturing desired skeletal and anatomical positions for other parts of the body, including for example, arms, legs, elbows, and knees. Various embodiments of devices adapted to accomplish these functions will now be described with reference to the Figures where corresponding parts are referenced throughout this description by similar numbers.
In one embodiment, the orthopedic device is designated generally by the number 10, as shown in
As shown in
The end chambers 12, 16 are disposed at opposite ends of the device 10, which is substantially rectangular as shown, but may also be round, oval, square, triangular, or other polygonal shapes. The end chambers 12, 16 form opposite ends of the device 10. The end chambers 12, 16 are separated from one another by intermediate chamber 14. The sides 30 of the device 10 are formed in part by each of the individual chambers 12, 14, 16. In one embodiment, end chamber 16 is disposed at a superior end of the device 10 while end chamber 12 is disposed at an inferior end. In one embodiment, end chamber 12 has an interior volume that is slightly larger than end chamber 16. In another embodiment, end chambers 12, 16 have substantially similar interior volumes. A central chamber 14 comprises a hammock section 26 that is suspended at opposite sides 30 of the device 10. Two open sections 32 are bounded by the hammock section 26 and one of the end chambers 12, 16.
The device 10 includes a fluid pressure regulating system 22 consisting of individual control valves 34, 36, 38 for controlling the flow of fluid from the fluid coupling 20 to the individual chambers 12, 14, and 16, respectively. The control valves 34, 36, 38 may be actuated to allow pressurized gas or liquid to flow from the fluid source (via coupling 20) into the respective chambers 12, 14, 16. Further, the same control valves 34, 36, 38 may also be actuated to release pressurized gas/liquid from the chambers 12, 14, 16 to the atmosphere or to a scavenging or collection mechanism. In this manner, the control valves 34, 36, 38 may be used to adjust the size, shape, rigidity and compliance of the individual chambers 12, 14, 16. Thus, as shown in
In another embodiment, an orthopedic device similar to that described in Embodiment 1 is designated generally by the number 40, as shown in
Each of the individual chambers 12, 16, 42, 44 of device 40 includes an inlet port 46 that may be used as a one-time fill port or as an inlet-outlet adjustment port. Further, each of the individual chambers 12, 16, 42, 44 may be filled with a common fluid, gas, or liquid or some combination thereof. In one embodiment, the individual chambers 12,16, 42, 44 may be filled, at the time when the patient's anatomy is to be captured or set, with a solidifying fluid such as a quick setting polyurethane or polystyrene foam. Thus, the device may be placed adjacent the patient's anatomy and a suitable amount of the solidifying fluid can be injected into the individual chambers. Once the contents of the chambers 12, 16, 42, 44 harden and cure, the desired anatomy will be advantageously captured. Alternatively, the individual chambers 12, 16, 42, 44 may also be pre-filled or lined with a thermoplastic or thermoplastic elastomer substance, which allows the device 40 to conform to the patient's anatomy when heated to a predetermined temperature, but which also hardens to retain the desired shape once cooled.
In the aforementioned embodiments and in the embodiments described below, a reference datum may be used in conjunction with the orthopedic device 10, 40 to establish the desired anatomical position. The reference datum may then be used during subsequent anatomical re-positioning as a verification that the desired anatomy is in fact replicated. Those skilled in the art will comprehend that a variety of different measuring reference tools may be used. For instance, a linear measurement to a data point or between surfaces may be taken. To that end, a datum feature 15 may be included on the device 10 as shown in
Another non-limiting example of a reference feature is an inclinometer 35 as shown in
In one embodiment, the orthopedic device is designated generally by the number 50, as shown in
One end 54 (the fixed end) of the flexible sheet 52 is fixedly attached to the rail 62 using a pin, screw, rivet or other suitable attachment means 64. The opposite end 56 (the free end) of the flexible sheet 52 is coupled, directly or indirectly, to the moveable adjustment knob 60. The adjustment knob 60 and its integral pinion gear move toward or away from the fixed end 54 as the knob 60 is rotated. The adjustment knob 60 may be locked in place to retain the curvature of the flexible sheet 52 using a dedicated locking device (not specifically shown). Alternatively, the knob 60 may be frictionally locked by the presence of an interference between the rack 58 and pinion gears.
As shown in
The device 50 may also include a set of linear bearings 66 that couple the rail 62 to a base plate 68, which may be mounted onto a table or wall (not shown). Alternatively, the rails 62 may be coupled to a table or wall using the linear bearings 66. Alternatively, the rails 62 may be coupled directly to a table or wall without any linear bearings 66. The bearings 66 allow adjustment of the position of the device 50 as a whole. Thus, the device 50 may be repositioned as needed to accommodate patients having a different height or different anatomy.
In another embodiment, an orthopedic device similar to that described in Embodiment 3 is designated generally by the number 65, as shown in
In one embodiment, the orthopedic device is designated generally by the number 70, as shown in
The individual adjustment mechanisms 80 include extending or telescoping support members 82 that move the rollers 78 in the Y-direction. The support members 82 extend between the rollers 78 and a base member 84. The support members 82 may be threaded, pneumatic, or spring biased to impart motion to the rollers 82 in the Y-direction. The position of each individual roller 82 in the Y-direction is set by manipulating an actuator 86 that serves to control the appropriate translation mechanism (e.g., threads, air pressure, spring-bias lock, etc. . . . ). Similarly, the position of each adjustment mechanism 80 in the Z-direction is set by manipulating an actuator 88 that serves to control that appropriate translation mechanism, which may also comprise pneumatic, spring biased, or threaded mechanisms. The actuators 86, 88 may inherently function as locking members, but dedicated locking mechanisms (not shown) may be appropriate and perhaps even desirable for added stability. Appropriate locking mechanisms will vary according to the translation mechanism implemented and are known by those skilled in the art. Some non-limiting examples include friction locks, gear locks, pins, clamps, seals (in the case of pneumatic devices), and the like.
In practice, this device 70 may be mounted to a wall or mounted or laid to rest on a table. The subject anatomy is then brought into contact with the flexible sheet 72 and the actuators 86, 88 are then manipulated to adjust the position of the individual rollers 78, and consequently the flexible sheet 72, to closely match the anatomy. Alternatively, the rollers 78 may be adjusted to impart a desired position different than the existing neutral position for the subject anatomy.
In one embodiment, the orthopedic device is designated generally by the number 90, as shown in FIGS. 13,14,15, and 16. The device 90 resembles a pillow and comprises a flexible sheet 92 that covers an array of blunted or rounded pins 96. Initially, the pins 96 are held in place in an extended first position by a perforated base 98, as shown in
A dedicated locking mechanism may be employed (as shown in
As with other embodiments described above, the orthopedic device 90 may be used to capture or register a desired anatomical position. The patient (standing or lying) is brought into contact with the device 90 with the desired anatomy in the desired position. The desired position may be a natural or neutral position or a target position. As the patient contacts the device 90, the pins 96 retract into the suspension base 100. Then, once the pins are secured in position with the appropriate locking mechanism (e.g., actuator 102, curing material 104), the patient may simply lift the desired anatomy off the device 90. At this point, the flexible sheet 92, which follows the contour formed by the top of the pins 92, forms a negative of the desired anatomical position. In one embodiment, the pins directly contact the patient and there is no flexible sheet 92.
In one embodiment, the orthopedic device is designated generally by the number 110, as shown in
The device 110 further comprises a control box 120 from which positive (+) 122 and negative (−) 124 leads are electrically coupled to magnetizing terminals 126 positioned on the frame 114. The controlling function may also be implemented in a controller (not shown) implemented directly on or attached to the frame 114. The magnetizing terminals 126 may comprise plates that are opposed to one another so that the presence of an energy source provided by the control box 120 via the leads 122,124 creates a magnetic field between the terminals 126. The resulting magnetic field is advantageously strong enough to cause the MR fluid 118 to solidify in its present shape.
In practice, the desired anatomy is placed in the desired position on or against the bladder 112 and the uncharged MR fluid 118 flows to conform to the desired anatomy. Once the appropriate position is achieved, the control box 120 is activated to impart a magnetic field on the MR fluid 118 to retain the desired shape. Rechargeable battery sources (not shown) may be coupled to the control box 120 (and hence, the magnetic terminals 126) to retain the desired shape for an extended period of time at least until the desired contour is no longer needed. Furthermore, the use of rechargeable batteries enhance the portability of the overall device 110.
In each of the above embodiments, suitable materials for the orthopedic devices 10, 40, 50, 65, 70, 90, and 100 may include aluminum, plastic resin, or some other radiolucent materials. Alternatively, to create a distinctively different object during imaging processes, radio-opaque materials may be used to distinguish the subject anatomy.
The present invention may be carried out in other specific ways than those herein set forth without departing from the scope and essential characteristics of the invention. For example, while the various embodiments have been described as discrete entities, the characteristics of each embodiment may be combined to form even more embodiments. For instance, the MR fluid may also be suitably implemented in the multi-chamber devices discussed above. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.
