Patent Application
20230263686
The orthopedic field of hip preservation has grown tremendously in the past two decades. Very sophisticated surgeries are now being performed through arthroscopy at the hip joint. The hip joint is a ball and socket joint that has 3-degrees of motion, which means the hip moves not only linearly but also rotates. The post-operative rehabilitation of these patients is instrumental in the surgical and patient outcomes regarding pain, mobility and ultimately function.
One of the most significant and common post-operative complications is the formation of scar tissue and adhesions in the joint and surrounding soft tissue. Currently, continuous passive movement (CPM) machines or device (used interchangeably herein) are used post-operatively in an effort to help minimize scar tissue production and help prevent formation of adhesions between joint capsule and labrum.
The benefits of continuous passive movement are significant. Among the many benefits are that CPM helps to avoid joint stiffness in the first few days/weeks post-surgery, which in turn decreases the chance of progression to fibrosis of the joint. Further, CPM can increase synovial fluid in joint space, improve joint ROM by preventing soft tissue contractures, and improve active hip range-of-motion (ROM) (specifically hip abduction). CPM also helps with maintenance of articular cartilage, relieves pain and helps reduce muscle spasm. Other benefits include the assistance in the stimulation of tissue remodeling and enhanced nutrition, the minimization of joint hemarthrosis and periarticular edema and the decrease in the need for joint manipulation under anesthesia.
A post-operative hip joint ideally requires a motion that is not only linear but also rotational, commonly known as Hip Circumduction (HC), so that the full functional mobility of the joint is addressed. Post-operatively, patients need to complete a significant number of hours (4-6 hours typically) of CPM use on a daily basis. Typically, this treatment is required for the first 4-6 weeks after surgery. In some instances, involving micro-fracture treatment to the joint, CPM is recommended for up to 12 weeks post-operatively.
Currently, there are machines or devices that assist or provide linear motion to the hip joint. However, there are no medical devices that provide the critical circumduction of the hip. Instead, post-operative patients must use a knee CPM machine, which is severely limited in the movement it provides. These prior art knee CPM machines major disadvantage is that it provides only linear (hip flexion/hip extension) movement while the patient lies on their back (supine).
As a result, the HC motion must currently be provided by a licensed physical therapist. This is typically provided when the patients go to the therapist office for his/her physical therapy sessions. As a practical matter, these physical therapy sessions are typically scheduled only 3 times per week. Additional HC motion sessions should ideally be performed at a minimum of 6 times per day in at least 20 minute sessions. But this is often impractical or insufficient. These at-home sessions are typically provided by a caregiver at home that is unlicensed and, generally, insufficiently trained. The home caregiver is typically trained by the medical team on how to perform HC and is then asked to do this for 4-6 weeks.
Unfortunately, for a variety of reasons this arrangement leads to a high degree of non-compliance. First, the HC motion is physically challenging to perform and at-home caregivers tire very easily due to the strain of lifting the leg fully and a general unfamiliarity with the routine. Second, the patients usually have a poor ergonomic set up at home, which makes a difficult situation more challenging. Third, both patients and caregivers often have a low level of confidence that the motion (HC) is performed properly and adequately. These factors and others add up to produce poor compliance with the HC motion and poorer long-term outcomes as a result.
The prior movement machines all have significant drawbacks. Some post-operative patients attempt to use an infant device known as the Mamaroo in order to provide HC motion. In practice, patients fill the device with pillows or other soft material and then place their operative leg on top of it. The significant drawback to this technique is that it provides only a very small, minimal amount of rotation. The Mamaroo is designed as an infant seat that moves. As such, it is not safe to place it on a bed or table; patients instead attempt to get down onto the floor to use it and then safely get up off the floor while using 2 crutches, a hip brace and only apply 20 pounds of weight-bearing (WB) pressure through their operative leg.
There is a need for a device that allows for patients to safely receive both linear motion of hip flexion/hip extension and the rotational motion of hip circumduction. There is a need for a device that provides the rotational motion of hip circumduction to a patient while lying in their bed or on a physical therapy table.
A method and device or machine for safely providing or performing the motion of circumduction as well as linear hip flexion/extension to a patient in need is provided. The device or machine (used interchangeable herein) is preferably a continuous passive movement device. The device gives full support to the operative leg and controls the true amount of hip external/internal rotation by keeping the hip in a neutral position, relative to rotation. In operation, the patient is typically in a side-lying position with the operative leg on top. In this position, the motion of circumduction as well as linear hip flexion/extension can then be performed on the patients safely and effectively. Other positions of the patient can be used and will usually be patient specific.
According to the invention, the patient typically lies on his or her side with the operative leg on the top. In this position, it is convenient to consider the Y-axis to be along the length of the body (head to feet), the X-axis to be the plane from the front of the body to the back of the body, and the Z-axis extends from the ceiling to the floor or through the vertical height of the pelvis. In this position, the method and hip CPM device safely generates motion of the patient's leg along all three (X, Y and Z) axes. Again, other positions are possible for the patient to be in, which will depend on the condition and needs of the patient. The arms of the device provide the necessary movement of the patient's leg that accurately simulates the movement of the patient's leg that a physical therapist would provide. Specifically, the CPM machine of the present invention creates multidimensional movement of the patient's hip as well providing the necessary therapeutic movement in a home or other environments, such as in and out-patient clinics.
The significant advantage of the present invention is that the patient no longer needs to depend on another person, i.e., medical professionals at an office or caregivers at home, to offer this CPM treatment. Further, the patient does not need multiple machines to achieve the necessary movements of the leg after hip surgery. Instead, a patient will need only one device to perform both necessary motions (Hip flexion/extension & Hip Circumduction). The patient will be able to get into and out of the hip CPM independently. Moreover, physical therapy clinics will be able to use the hip CPM instead of physical therapists manually performing this motion for 20 minutes of the patient's therapy session.
In some embodiments the CPM machine is adjustable in height and the components can fold in or fold down on itself towards the main body of the device. In the folded position the machine is compacted to a smaller and more convenient shape such that it is easily transportable, to patient's homes for example. Internally, the machine contains the means to move the arms in an orbital pattern along an oblong-type axis with the necessary mechanics/engineering that moves the leg in a circumduction, in both a clockwise and counterclockwise, manner as well as into hip flexion/extension. The movement generated will be three dimensional allowing for the robotic arm or arms to move towards and away from the body (X-axis, hip & knee flexion/extension), up towards the head and down towards the feet (Y-axis, hip & knee flexion/extension) and up and down towards the ceiling/floor (Z-axis, hip abduction/adduction).
Referring to the FIGs, embodiments of the hip CPM machine or device 1 are illustrated. The main body 10 is generally a rectangular shaped housing containing the means to move the arms e.g., the motor, gears, actuators etc. of the CPM machine 1. The main body 10 can be a variety of shapes, it is not necessarily rectangular. The main body 10 contains aperture or apertures 12 that permit an arm or arms 30 to be connected on the interior of the main body 10 and extend into the interior of the main body 10 and extend outward away from the main body 10 in a direction substantially parallel to the ground. The main body 10 may be constructed of any suitable material so long as it is sufficiently strong enough to house the necessary components of the device and support the weight of a leg.
The stand or base 20 provides support for the main body 10. The base 20 of the embodiment of
The device contains one or more robotic arms 30 extending from the main body 10 of the machine 1.
As discussed below, embodiments with more than one arm are envisioned. The robotic arm 30 hold and support the operative leg (not shown) at an area or areas of the leg to fully support the weight of the operative leg. The arm or arms 30 preferably extend out from the main body 10 of the device 1 substantially parallel to the ground and perpendicular to the main body 10. The arm or arms 30 are preferably of adjustable length so that the arms 30 can reach the patient when the main body 10 of the device 1 is on the floor and the patient is on a table or other support.
The arm 30 is attached or connected to the main body 10 via a band or sleeve 32 that substantially encircles the main body 10. The band or sleeve 32 moves up and down the height or a portion thereof of the main body 10, thereby moving the arm 30 in the up and down direction, shown with an arrow. The arm 30 moves in the up and down direction via the band 32. The band 32 is guided by vertical slots or channels 14 on the sides of main body 10. The band 32 is connected to an actuator and or motor assembly on the interior of the main body 10, which moves the band 32, which in turn moves the arm 30. The arm 30 can further move side-to-side and in-and-out with respect to the main body 30. Arrows illustrated how the arm 30 can move along three different axes with respect to the patient, thereby moving the patient's leg in three dimensions. The arm 30 can move in a side-to-side direction with respect to the body guided by horizontal slot 34 in the band 32. Finally, the arm 30 can move in the in and out direction with respect to the body 10. In this embodiment, the arm 30 has a telescopic sleeve 36 that moves the hand 40 in the in and out direction. The arm 30 can be programmed to move in both directions, i.e., clockwise and counterclockwise manner.
Each arm 30 has a hand 40 attached to the end 34 of the arm 30. The hand or hands 40 are shaped such that it can securely support the patient's leg but also move the patient's leg as the arm or arms 30 of the machine 1 move. Preferably the hand 40 is concave or U or V-shaped. Even more preferably the hand is adjustable to accommodate patient's legs of the different shapes and sizes. The hand 40 may be secured directly to the end 34 of the arm 30 as shown in the embodiment of
Alternatively, the hand 40 may be secured to the end 35 of the arm 40 by way of a joint or swivel to accommodate the movement of the arm 30 as illustrated in
In one embodiment, the movement generated by the machine 1 allows for the robotic arms to travel different distances (thigh arm vs lower leg arm) and the movements coupled (along more than one axis of movement at a time) in order to replicate human motion. In operation of this embodiment, the two arms 30a and 30b simulate human movement via the robotic arms 30a and 30b and the programmed movement. The arms 30a and 30b in this embodiment do not have to move in tandem, but the excursion/distance moved by each arm will be different, just as the movement of the arms of a human would be different.
In use, the hip CPM machine 1 will typically be positioned on the floor or other secure support.
The base, stand or legs 20 are secured to the bottom portion 12 of the main body 10. The base, stand and/or legs 20 are preferably adjustable and contains anti-tipping kick-stands or supports 24 that can be locked in positions (shown in
the hands 40a and 4b can swivel with respect to the arms 30a and 30b as the leg 52 is moved into different positions by the arms of the hip CPM device 1. Generally, the hand or hands 40 can be shaped and configured to support the leg 52 and foot of the patient 52 as needed. In operation in either embodiment, the arm or arms move in three dimensional patterns (which is preprogrammed by the user or operator) to passively move the leg 52 in a therapeutic motion.
The primary components can be modified in numerous ways to achieve the desired function.
In one embodiment, the device is programmable and allows for incremental changes in the amount of range of motion (ROM) provided to the leg 52. Preferably, the device includes a program storage device readable by the machine, tangibly embodying a program of instructions executable by the machine to cause the machine to move the arms of the machine in a prescribed motion. This is accomplished with integrated or even external software and hardware that drives the predefined motion of the arms 30 and hands 40 of the machine 1. Most typically, this would be accomplished with an integrated computer or the like receiving input from the user and transmitting signals to the actuator and/or motor controlling the arms. The specific path that the arm 30 is moved is defined by the operator and determined by the operator according to the specific needs of the patient.
This information and execution may be accessible via an application interface on a smart phone for example, which can be communicate with the device. The hip CPM device and/or the application may be set up for telemetry (data collection) of the patient for various parameters. The ROM provided may be correlated with post-operative protocol parameters, as per the medical provider's orders. The programmable device controls the direction, speed and special movement of each arm 30. Input parameters may include the height of the patient, length of the leg etc. so that the optimum movement is provided to the patient.
Preferably, the motion ranges accommodate the following types of movement and conditions, although other ranges are possible under certain situations. Since the hip will be held in a relatively neutral position for rotation, the arms can create the circumduction motion more so through the combined movements of hip flexion/extension and hip abduction/adduction. Hip abduction means that the thigh moves away from the body laterally. Hip adduction means that the thigh moves towards the midline of the body.
The resting/open-packed position of the hip is such that the hip is in about 5-8 degrees of abduction, so this would be our starting point with the thigh 5-8 degrees just north of the horizontal line. Preferably, the hip would not exceed 15 degrees of hip abduction during circumduction. With this limitation, the most adduction that would occur with the circumduction motion would be 25-30 degrees below the horizontal line. This angle will of course vary a bit based on the width of the patient's pelvis.
However, in other it is safe given post-operative precautions to slowly and gently bring the thigh towards the midline of the body especially if there are only 45 degrees of hip flexion occurring at the same time. This will be up to the medical professional to decide.
In the typical application for the typical patient, a medical professional may avoid a full 30 degrees of adduction while at 90 degrees of hip flexion. The motion range of the machine can be programmed accordingly. Again, these types of decisions will typically be determined by the medical professional according to the specific needs or the patient.
In some embodiments, the machine 1 will measure the weight of the patient's leg and determine the amount of force to exert to safely move the leg through its trajectory or path and the prescribed range of motion. The machine 1 in one embodiment uses a laser or similar technology to determine the proper position of the arms 30 and hands 40 to match the pelvic width of the patient. Through a mechanical, mechano-electrical and software engineering design, with an application interface, the side-lying hip CPM device 1 provides a customized intervention/treatment to the patient. Additionally, the app optionally provides telemetry so that data can be collected and analyzed.
The movement of the arms 30 can produced by any means know in the art. The means will typically be some type of actuator or motor or some combination of both. For one example an electric actuator or actuators is paired with a motor or motors to create the linear and/or rotary motion of the arms 30. Electric actuators are preferred as it tends to be more accurate, reliable and repeatable compared to hydraulic and pneumatic actuators. There's also less friction generated, which directly translates to less wear and tear and a reduction in the frequency of maintenance that is required. Electric actuators also provide a quieter operation, which can be especially helpful in-patient settings. The actuators and/or motors are coupled to the integrated or external computer.
There will be various modifications, adjustments, and applications of the disclosed invention that will be apparent to those of skill in the art, and the present application is intended to cover such embodiments. Accordingly, while the present invention has been described in the context of certain preferred embodiments, it is intended that the full scope of the invention be measured by reference to the scope of the following claims.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2022/031653 | 5/31/2022 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63195254 | Jun 2021 | US | |
| 63246903 | Sep 2021 | US |
