Apparatus for treating knee abnormalities

Abstract

A method of treating knee abnormalities includes securing the portion of the leg above the knee to a stationary object and securing the portion of the leg below the knee to a movable support. A force is applied to the movable support to stretch the knee joint. Apparatus for carrying out the method is also disclosed.

Claims

1. Apparatus for treating abnormalities in the knee comprising; a) a chair forming a seating surface for a patient, the chair having a lower laterally extending rod, b) means for securing an upper portion of the patient's leg above the knee to the seating surface, c) a support platform movable with respect to the seating surface, d) means for securing a lower portion of the patient's leg below the knee to the support platform, wherein the means for securing the lower portion of the patient's leg is axially movable relative to the support platform, e) means for applying a tension force to the support platform whereby a tension force is applied to the knee joint for causing the knee to be stretched in an axial direction and adjacent bone surfaces of the knee to move away from each other, and f) a main housing for supporting the support platform, the main housing being axially fixed to the seating surface during operation and the main housing being laterally adjustable along the seating surface via a tubular bearing that is slideably mounted on the rod of the chair; wherein the main housing includes side tracks extending along the axial direction and the main housing including a bottom surface having includes rollers, the side tracks and rollers being used to axially adjust the main housing with respect to the seating surface.

2. Apparatus as claimed in claim 1 wherein the support platform is slideably mounted for axial movement on the main housing.

3. Apparatus as claimed in claim 1 wherein the means for securing the lower portion of the leg to the support platform includes a strap and an inflatable bladder adapted to be positioned between the strap and the support platform.

4. Apparatus as claimed in claim 1 further including a force controller for regulating the means for applying a tension force.

5. Apparatus as claimed in claim 1 further including a foot support mounted on the support platform.

6. Apparatus as claimed in claim 1 including a force sensor for measuring the tension force applied by the means for applying a tension force.

7. A method of treating abnormalities in a knee of a human including the apparatus of claim 1, the method comprising; a) securing a portion of a leg above the knee to the seating surface, b) securing a portion of a leg below the knee to a support platform, by the means for securing a lower portion of the patient's leg, wherein the support platform is axially movable with respect to the seating surface, and wherein the means for securing an upper portion of the patient's leg is axially movable with respect to the support platform, and c) applying the tension force to the support platform, whereby adjacent bone surfaces of the knee are stretched in the axial direction.

8. The method of claim 7 wherein the leg is secured to the support platform at a location between the knee and an ankle of the human being treated.

9. The method of claim 7 including maintaining the portion of the leg above the knee and the portion of the leg below the knee in a generally axially aligned position as the tension force is applied to the support platform.

10. The method of claim 7, wherein the leg is fully extended when the knee is stretched in the axial direction.

11. The apparatus of claim 1, wherein the leg is fully extended when the knee is stretched in the axial direction.

Description

III. BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a side view of an embodiment of the invention.

(2) FIG. 2 is a frontal view of the embodiment of FIG. 1.

(3) FIG. 3 is a perspective view of an embodiment of the invention,

(4) FIG. 4 is a perspective of a portion of the apparatus.

(5) FIG. 5 is a perspective view of the extension mechanism for the lower leg support member.

(6) FIG. 6 is a perspective view of the front portion of the extender attached to the underside of the main housing member.

IV. DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE DRAWINGS

(7) As shown in FIGS. 1 and 3, an embodiment of the invention includes two components fixed together. The first component 6 is a seating arrangement for the patient. It includes a support frame 14, a back rest 13, and a seating surface 15. Support frame 14 includes a laterally extending rod 19.

(8) Seating arrangement 6 also includes a u-shaped cut out section 9 (FIG. 3) in a middle portion of the seat to accommodate a pair of strap guiding bars 52, 57 secured to the frame. The two sides of the chair include a support bar 53 and 54 to which a first end of the straps 71 are secured to. Portion 72 of the strap is adapted to be placed over the patient's upper leg portion, through loop 52 and then back over portion 72 as shown at 73.

(9) The lower leg support and stretching component includes a first guide housing 21 as shown in FIG. 4 that includes a tubular bearing 20 that is adapted to slide laterally on rod 19. A main housing member 16 which includes ground engaging rollers 20 is slideably attached to guide housing 21 by conventional side tracks 18 which slide in complementary shaped tracks attached to an inner wall of main housing 16. The axial position of main housing 16 with respect to guide housing 21 can be adjust by turning a knob 23 which has a pin sliding in slot 8 provided in the top surface of guiding housing 21. The pin is threaded to receive a nut which slides under grove 8.

(10) A lower leg support platform 25 is slideably mounted on the main housing 16 and includes a pair of downwardly extending side flaps 30. A plurality of adjustment holes 26 are located on the top surface of support platform 25. Holes 26 includes a slot portion and an enlarged portion to accommodate pins, which have an enlarged head portion, extending downwardly from cushions 29, 31 in a known manner. A first strap 80 tightly surrounds and is attached to cushion 29. A second strap 85 having end portions 83, 84 is secured to the top portion of first strap 80. Hook and loop fasteners are provided on end portions 83, 84 respectively so that the lower portion of the leg below the knee can be secured to cushion 29 which is secured to platform 25. Cushion 30 is for supporting the patient's foot and is optional. It may also include a securing strap. The support platform 25 includes side mounted tracks 22 as shown in FIGS. 1 and 5 that slide within complimentary shaped rails 51 secured to the outer surface of main housing 16. Rails and tracks that are commonly used in desk drawers may be used as an example, however any known mechanism for slideably supported one member within another may be used.

(11) Lower leg supporting platform 25 includes an end plate 50 as shown in FIG. 5. One end 27 of a progressive force linear actuator available from Progressive Automations is connected to end plate 50 via a force sensor 35. The other end 95 of the linear actuator is fixed to the underside of top surface 24 of main housing 16 by a bracket 58. Thus extension of the linear actuator will cause support platform 25 to move with respect to main housing 16 in an axial direction as depicted at 54 in FIG. 1.

V. MODE OF OPERATION

(12) In operation, a patient is seated and the leg is fully extended so that the lower portion of the leg below the knee is supported by cushion 29 and the foot rests on cushion 31. Housing 16 may be axially adjusted as necessary as shown at 55. Housing 16 is laterally moved so as to be aligned with the knee to be treated. The upper portion of a leg is secured to the chair frame 14 by a strap having hooks and loops fasteners for example. The strap may be mounted on one side of the chair at 53, placed over the knee at 72 and through the space between bar 52 and the U-shaped cutout, and then tightened folded back over the knee at 73 and secured to section 72 by a hook and loop fastener.

(13) The lower portion of the leg is secured to the movable platform 25 on cushion 29 in a similar manner, however the arrangement for securing both portions of the leg to the chair support frame and the moveable support platform may include any known arrangement.

(14) Optionally an inflatable bladder 55 having an air pump 40 may be positioned between the leg portion and the strap to firmly secure the leg portion to the support platform. With the leg secured above and below the knee, a linear force is applied to the knee via linear actuator 95, 27 and support platform 25 which results in the knee joint being stretched between 0.0 and 10 millimeters for example. The amount of force, duration of the force and intervals between the application of force can be varied by a suitable control mechanism known in the art. The amount of force applied may be in the range of five to thirty pounds, for example with intervals of 0 to thirty seconds, again for example. For a given cycle the applied force can vary from a given starting value to a greater end value, for example eighteen to twenty-two pounds. A control module 69 is attached to housing 16 for inputting data into a central processor which controls movement of the linear actuator.