Patent ID: 12186258

DETAILED DESCRIPTION

With reference to the enclosed figures, and in particular to the example ofFIG.1, an improved orthopaedic external fixation system with removable rails or skates is disclosed.

It is worth noting that the figures represent schematic views and are not drawn to scale, but instead they are drawn so as to emphasize the important features of the disclosure. Moreover, in the figures, the different elements are depicted in a schematic manner, their shape varying depending on the application desired. It is also noted that in the figures the same reference numbers refer to elements that are identical in shape or function. Finally, specific features described in relation to an embodiment illustrated in a figure are also applicable to the other embodiments illustrated in the other figures.

Without limiting the scope of the present disclosure, the system ofFIG.1is globally and schematically indicated with the reference number1and may be considered part of the wide family of external fixation devices. Generally, external fixation devices are commonly used on both the upper and lower limbs for both adults and children in a variety of surgical procedures including limb lengthening, deformity correction and treatment of fractures, mal-unions, non-unions and bone defects.

One common external fixation device is known as Taylor Spatial Frame that is a hexapod type of device comprising at least two external fixator rings attached to bone segments by wires or half pins and connected together by six interconnecting struts that may be lengthened or shortened as necessary. Adjustment of strut lengths allows spatial manipulation of the bone segments in all the allowed six degrees of freedom (e.g., lengthening/shortening, external/internal rotation, anterior/posterior horizontal translation, medial/lateral horizontal translation, anterior/posterior angular translation, and medial/lateral angular translation) to correct linear, angular and rotational deformities simultaneously.

The system1of the present disclosure may be considered a hexapod type of device but the structure and configuration of the rings and the struts may even be similar to a Taylor Spatial Frame even if a TL-Hex hexapod frame is the preferred solution for adopting the improvement of the present disclosure.

First of all, the system1includes at least a proximal ring2realized from a suitably strong and rigid material such as a metal, metal alloy, plastic, composite, or ceramic. The body portion of the ring includes substantially equally spaced apertures or holes3positioned arcuately therein and extending through an upper ring surface to a lower ring surface.

Moreover, the ring2comprises substantially equally spaced angled flanges4extending radially from the outer surface of the ring and provided with two accessible lateral apertures5and central aperture6on their outer surface.

During an operation, the arcuately positioned holes3are used to connect wires and half pins inserted to the bone segments while angled flanges4and the accessible lateral apertures5are used for attachment of ball joints of the connection struts10and locking them in place by a conventional set screw of the central aperture6(not visible).

The apertures5are positioned obliquely in the angled flange4to provide the optimal range of motion for the strut10when connected to the fixator ring2. In addition, struts10can be connected to other accessible lateral apertures5on outer surfaces of the ring2.

Although the shape of the fixator ring or rings2is substantially circular, it is to be appreciated that the shape of this fixator external supports can vary to accommodate the physical contour of various body parts to which the fixation system1would be attached. For example, the fixator external supports can be configured to have an oval shape, D-shape, U-shape, C-shape, or other irregular shapes without departing from the principle of the present disclosure. In some exemplary embodiments, an elliptical fixator ring (not shown) may be particularly advantageous.

Moreover, the fixator external supports or rings2may be a complete circle (full ring) or a segment or portion of a circle (e.g., half ring, ⅓ ring, ¼ ring, ⅝ ring and other) that is either used alone or joined with other segments or portions of the ring to form a complete ring (not shown). In any case, a skilled in this art understands that a circular or semi-circular foot fixation element may include one of the above-mentioned portions of a circle.

The system1of the present disclosure includes at least a distal semi-circular external support or U-shaped foot plate7as a foot fixation element. We will later identify as front of the fixation system1the portion of the fixator located opposite to the curvature of the U-shaped portion.

This distal foot plate7includes a plurality of equally spaced apertures or holes8positioned arcuately therein and extending through an upper foot plate surface to a lower foot plate surface.

Moreover, the foot plate7comprises spaced angled flanges9extending radially from the outer surface of the foot plate and provided with an accessible aperture on their outer surface. As for the ring2, even for the foot plate7the arcuately positioned holes8are used to connect wires and half pins inserted to the bone segments while angled flanges9with their accessible apertures are used for attachment of connection struts10.

The ring2and the foot plate7are interconnected as shown inFIG.1through a plurality of connection struts10, for instance six struts10to form a hexapod type fixation configuration.

The fixator rings2and the foot plate7may be constructed of any material that provides the structural rigidity necessary for fixation such as metal, metal alloy, carbon fibers, plastic, ceramic and so forth.

A skilled in this art will readily understand that numerous connection struts10may be attached at various positions about the external fixator rings2and7. The angle of each the connection struts10relative to the proximal external fixator ring2and the distal external fixator half-ring7may be varied; even the length of the connection struts10may be varied and adjusted.

The connection strut10includes opposite ball joints13and14that can be attached to the outer surface of a proximal fixation ring2or a distal foot plate7. More particularly, these joints13,14are structured with a ball stud15attached to the aperture5of the flange4.

According to embodiments of the present disclosure, a connection strut10of the system1is configured with a telescopic outer housing11and inner tube with a threaded rod17that allows for rapid adjustment in length. Gradual strut length adjustment is achieved by rotating a distraction knob12, which is provided for advancing or reducing the length of the threaded rod17.

In embodiments of the present disclosure the strut housing11may have graduation marks16indicating the lengths of the strut10as a relative value. The graduation marks16do not necessarily have to indicate the effective length of the strut10but could indicate the remaining length of the threaded rod for gradual strut length adjustment.

The orthopaedic external fixation system1of the present disclosure is further equipped with removeable rails or skates20allowing the patient to walk without abutting his/her foot on the walking surface on the ground.

Since these rail or skates20are identical to each other only one of them will be described in detail later with reference to the example ofFIG.2.

In accordance with the present disclosure, the system1further comprises connecting members30having a first end configured to be connected to an aperture in the distal foot plate7and a second end connected to a corresponding flange24or25of the skate20.

This connecting member30comprises a cylindrical body31extending along an axis that is substantially perpendicular to the skate20and has a through hole arranged transversely with respect to the extension axis of the cylindrical body31so as to be able to receive a bolt32for fixing to the skate20.

The cylindrical body31has a flat recessed portion around the hole so as to create a flat wall abutting against one of the flanges24,25.

The cylindrical body31has a blind threaded hole (not shown) at its opposite end to receive a fixing threaded rod for coupling to an aperture8of the foot plate7of the external fixation system1.

As a possible alternative, the cylindrical body31may also be structured like a shock absorber and be equipped with a central dumping spring33, for instance as shown inFIG.6. However, a shock absorbent spring might affect loading measurements and care should be taken to adopt springs of known and very accurate elasticity properties.

According to embodiments of the present disclosure the orthopaedic system1includes at least a load sensor40associated to at least one of said rails or skates20. The load sensor40may include load cells as sensitive elements as disclosed later in more detail. As an alternative, a different mechanisms of load measurement may be employed, for instance, a mechanism including strain gages or similar sensitive elements, etc.

Preferably, but not necessarily, a load sensor40is associated to connecting member30linking the foot plate7to the corresponding skates20. In the example ofFIGS.1and1Ait is shown a load sensor40associated to a connecting member30of the rear protruding portions25, that is to say the portion closer to the back end of the skate20.

In embodiments of the present disclosure the load sensor40may be coupled or associated to the skates20through a removable support.

In this respect, the load sensor40and its support may be considered an accessory device to be associated to an existing orthopaedic external fixation system equipped with removeable rails or skates to provide the same advantages of the present disclosure.

So, a rail or skate20equipped with the load sensor40may be considered a sensorized rail capable to detect a pressure force exerted on the foot or the limb.

In the example ofFIG.1it is also shown an envelope box60that may include and protect an electronic apparatus70cooperating with the fixation system1and that will be disclosed later. The envelope box60further includes a LED flag61and a speaker62. A proximity sensor63is also provided on the front portion of the envelope box60.

This proximity sensor is suitable for detecting the vicinity of a possible obstacle on the way of the patient and allows advising the patient of such an obstacle as we will see in the following description.

In this example ofFIG.1the electronic apparatus70is wired linked to the load sensor40though a wired connection44. However, a skilled in the art may easily understand that a wireless communication channel may be provided between the load sensor40and the electronic apparatus70of the envelope box60.

Moreover, the electronic apparatus70may even be located remotely from the fixation system1and the envelope box60that may remain just for hosting the flag61, the speaker62and the proximity sensor63, as will be later disclosed.

In the example ofFIG.2the skate20according to the present disclosure has a base21with a curved profile and a thinner orthogonally oriented connection body22arranged centrally and extended substantially for the whole length of the base21. The base21is curved with a curvature formed in accordance with requirements of the technology in this sector. The connection body22forms a kind of fin and projects from the base21of the skate20and extends over a length substantially equal to that of the skate1itself. The base21and the connection body22are shape coupled and fixed by means of at least a couple of protruding bumps26hosted by corresponding recesses formed

The upper profile23of this body22defines a couple of projecting flanges24,25.

The couple of flanges24,25are formed and shaped in the connection body23as protruding portions spaced one from the other for interconnecting with a fixation ring, more particularly with the distal foot plate7.

Each flange has a slot24a,25afor regulating the fixation of a connecting member30provided for fixing the rail or skate20under the foot plate7. a second end provided with a hole for allowing the connection to the slot24aor25aof the flanges24,25.

The two slots24a,25ahave dimensions which are different from each other; more specifically, the slot24awhich is arranged in the front of the skate20, with respect to the walking direction, has a longitudinal extension smaller than that of the other slot25awhich is arranged at the rear. For example, the longitudinal extension of the front slot24ais about 13 mm, while the longitudinal extension of the slot25aat the rear is about 20 mm, in a skate with a length of about 270 mm measured along a flat surface.

In addition, preferably the two protruding portions24and25are arranged at a different distance from the respective closest end of the skate20.

More particularly, the projecting member24, which could be defined as the front part, is placed closer to the front end portion28of the skate1compared to the distance between the other projecting member25and the rear-lying end portion29of the skate20.

In other words, there is a front protruding portions24and a rear protruding portions25, the front protruding portion24being placed closer to the front end portion28of the skate20than the rear protruding portion25with respect to the read end portion29of the same skate20.

Essentially, the two protruding portions24,25and consequently the respective slots24a,25b, are not arranged symmetrically with respect to a transverse central plane of the skate.

This skate base21hosts and supports a couple of load cells45representing in this case the load sensor40. In embodiments of the present disclosure even a single load cell45may be enough for the purposes of the present disclosure, for instance just the front load cell.

The load cells45are substantially flat and are hosted and protected in cavities41defined in the base21at the bottom of the skates20.

These load cells45present thinner flexible element46that is extended toward the end portion of the base21. An extreme end47of each flexible element46surfaces from the both the end portions of the skate20, as shown inFIGS.2and2A. In another embodiment of the present disclosure shown in the perspective view ofFIG.2Ba removeable cover element35is provided to be coupled to the curved base21of the skate20. This cover element35is a sort of overshoe of the base portion21of the skate20.

In this respect, the cover element presents opposite rounded portions34and36wrapping and overlapping the end portions28and29of the skate20.

For instance, this cover element35may be realized with a material having a rigidity different (e.g., softer or harder) with respect to the material forming the skate20. This cover element may be realized for instance like a sort of rubber tire.

Moreover, the bottom portion of the cover element35abutting the walking surface may be provided with a graven surface or a tread for dampening the impact of the walking steps.

If the cover element35is used just as an overshoe the extreme end47of the flexible element46of the load cells surfaces from the opposite end portions of the cover element, as shown inFIG.2B.

However, in a different embodiment shown in the example of theFIGS.2C and2D, the cover element35may host and support a couple of load cells45representing the load sensor40instead than the base21of the skate20.

In other words, the cover element35may be used to host the load cell45or an alternative structure of load sensor. In this manner, the load sensors are associated to the removable cover35instead than being hidden inside the skate structure.

Even in this embodiment of the present disclosure a single load cell45may be enough for the purposes of the present disclosure, for instance just the front load cell.

The load cells45hosted by the cover element35may be the same previously disclosed with reference to the base21of the skate20. More specifically, those load cells45are substantially flat and are hosted and protected in cavities defined in the cover element35abutting against the bottom curved profile of the base21of the skates20. Those load cells are kept as in a sandwich between the cover and the base21.

However, as an alternative solution shown inFIGS.2C and2D, the load sensor40may be configured as a flexible sensor48extended substantially for most of the length of the cover element35.

This flexible sensor48is structured as a strip sensible to resistive force and interconnecting sensing areas49. A commercial product known as “FlexyForce©” may be used for this purpose.

The flexible sensor48is laid down on the surface of the cover element35coupled to the bottom profile of the base21of the skate20while the external surface of the cover element35contacts the ground. In this manner the force discharged on the skate20is transmitted to the sensor48before discharging onto the ground.

The configuration of sensors45disclosed with reference to theFIGS.2and2A, or the alternative configuration of the flexible sensor48disclosed with reference to theFIGS.2C and2D, allows generating a map of the load acting on the surface covered by the sensors to obtain information not only on the quantity but also on the distribution of the load on the surface and on the modality of patient step.

The load sensors40,45or48are electrically coupled to an electronic controller50that may be either mounted directly onto the system1or used as a separate module wirelessly connected to load sensors.

In this respect,FIG.3shows a block diagram of an electronic apparatus70cooperating with the improved orthopaedic external fixation system1of the present disclosure.

The electronic apparatus70may be considered incorporating an electronic controller50and all the electric components allowing the implementation of a method for monitoring the pressure force exerted on a foot or a limb of a patient threated with the orthopaedic external fixation system1of the present disclosure.

Moreover, the same electronic apparatus70allows monitoring the dynamics of leg loading of a patient and preventing interference with surrounded objects while walking.

Those aims are achieved by a combination of hardware and software components that are disclosed hereinafter.

First of all, electronic apparatus70may be considered incorporating one or the other of the sensor components40,45or48previously disclosed. According to the previous passages of the present disclosure it is evident that one kind of sensor40,45or48may be adopted according to the different embodiment of the fixation system under consideration.

In any case, those sensors40,45or48have in common the possibility to generate a sensing signal linked or proportional to the pressure force exerted on a foot or a limb of the patient threated with the fixation system1.

Such a sensing signal may be an analog or a digital signal but for the purpose of the present disclosure we will take in consideration just digital signals to be elaborated by the electronic controller50and we will consider the analog signals as converted on site into digital signals.

Therefore, the load sensors40of the first embodiment disclosed inFIG.1may be considered equipped with a suitable analog-to-digital converter providing a digital signal corresponding to the analog detection.

The sensing signals detected by the sensors40,45or48are transmitted to electronic controller50through a transmitter and receiver52that is indicated inFIG.3as transceiver.

This transceiver52may be incorporated into the envelope box60mounted on the fixation system1or one or both the skates20. Therefore, the transceiver52is in communication with the proximity sensor63as well as with the LED flag61and the speaker62.

The transceiver52may be considered part of the envelope box60or may be considered an independent component associated for instance to the load sensor40.

The electronic controller50may be a structurally independent host device, for instance, a portable device such as a mobile phone or a smartphone, that is in communication with the electronic components of the apparatus70on board the fixation system1. The portable device may be a computer, a server, a laptop computer, a notebook computer, a tablet computer, a mobile phone, a wearable electronic device, a personal electronic device, or a portion or element of such devices.

The electronic controller50includes at least the following components: an input/output portion53, a timing portion54, a non-volatile memory portion55, for instance an embedded Flash memory, a volatile memory portion57, for instance a RAM. Other components are not disclosed being of a conventional type.

The electronic controller50is linked to a signaling portions58of the portable device, always part of the electronic apparatus70, including for instance a light flag56or a sound emitter59. The light flag56and the sound emitter59may be additional or alternative to the flag61and speaker62of the envelope box60on the fixation system1.

In more details, the electronic controller50receives signals from the load sensors40,45or48through the transceiver52and elaborates such signals according to computer programs stored in the non-volatile memory portion55.

The electronic controller50may elaborate the received signals comparing them with reference signals still stored in the non-volatile memory portion55.

The electronic controller50is coupled to the signaling portion58of the electronic apparatus70and may issue a flag signal upon detection of a threshold pressure force on said at least one of said rails or skates that overcomes a predetermined reference value stored in the memory portion55. The flag signal may be a video or audio signal such as a simple light or a warning alarm. This visual signal may be emitted by the led flag61or by the flag56of the portable device. Similarly, the sound signal may be emitted by the speaker62or by the sound emitter59of the portable device. Obviously, both the light or sound emitters of the electronic apparatus may be activated by the electronic controller50.

The electronic apparatus70has been disclosed in general terms limited to the understanding of the present disclosure. However, the electronic apparatus70may incorporate suitable hardware components comprising at least:a power supply battery;a microprocessor for data processing;volatile and non-volatile memory portions;an accelerometer for monitoring movement,a pair of interfaces for force sensors,an RGB LED light or display;a speaker;a USB port for IN/OUT data transmission,a module for wireless IN/OUT data transmission with Bluetooth and Wi-Fi protocol to external devices such as PCs, smartphones, wearable devices, or other devices with compatible connectivity.

Those components may be hosted inside the envelope60or, as previously disclosed, being part of an external accessory attachable to other devices such as a smartphone.

This electronic controller50is also equipped with dedicated software (downloadable smartphone application) that allows the processing of digital signals converted by force and movement analog signals. Moreover, the electronic controller50is configured for the storage and tracing of data and for handling remote connections with external devices.

The software applications installed on this controller50or in a non-volatile memory55also permits the surgeon to connect his PC via wireless or USB connection to an electronic unit assigned to the patient and through a dedicated graphic interface and to set a therapeutic protocol defined by configuring certain parameters including amount of load transmitted via the skates on the ground and/or number of steps per day performed by the patient.

More particularly, the software application verifies and confirms that the force and/or movement values transmitted by the sensor(s) falls within a range of force and/or movement values (minimum and maximum) defined by the surgeon. If this condition is not verified, the software sends visual and/or audio feedback via the appropriate interfaces (LED, speaker, smartphone, smartwatch, etc.).

Therefore, the fixator system according to the various embodiments of the present disclosure allows implementing a method for monitoring the pressure force exerted on a foot or a limb of a patient threated with said orthopaedic external fixation system with removable rails or skates; the method comprising the steps of:connecting at least a pair of rails or skates to a foot fixation element;associating a load sensor to at least one of said rails or skates;detecting an electric signal issued by the load sensor;elaborating said electric signal in an electronic controller coupled to said load sensor for issuing at least a flag signal upon detection of a threshold pressure force on said at least one of said rails or skates.

The four steps (Step 1, . . . , Step 4) of this method are reported inFIG.7as a sort of flow chart diagram.

As alternative, the fixator system according to the various embodiments of the present disclosure allows implementing a method for monitoring the dynamics of leg loading of a patient and preventing interference with surrounded objects while walking; the patient having a foot or a limb threated by said orthopaedic external fixation system with removable rails or skates connected to a foot fixation element; the method comprising:associating a load sensor to at least one of said rails or skates;detecting an electric signal issued by the load sensor;elaborating said electric signal in an electronic controller coupled to said load sensor for issuing at least a flag signal upon detection of a threshold pressure force on said at least one of said rails or skates.

The software incorporated into the controller50also stores the data related to the movement and the forces acting on the pads, calculating the frequency of events in which, in the face of feedback from the device, the force and/or movement value read by the sensors has/have remained unchanged (feedback ignored).

This system supports a patient to follow the medical protocol in compliance with signaling when he exceeds, for example, the load to be exercised on the joint, or when the number of daily steps taken is less or greater than that prescribed.

The figures from 4 to 6 shows alternative embodiments of the fixation system of the present disclosure wherein a different combination of load sensors and/or signaling components are provided.

For instance, as shown inFIG.4, and differently from the example ofFIG.1, the disclosed configuration may include a fixation system100with two load sensors40for each skate20resulting in two front sensors and two rear sensors to measure the overall amount of load transmitted to lower limb as well as to compare amount of that load on the lateral and medial sides as well as anterior and posterior sides of the foot during the gait cycle. The two front load sensors may even have a different sensibility if compared to the other rear load sensors, thus allowing to detect if the patient is walking properly or is applying a wrong load on the heel or the front portion of the foot. Each load sensor40is associated to connecting member30linking the foot plate7to the corresponding skates20.

The configuration ofFIG.4includes four load sensors40(two on each skate20) but with one load sensor dedicated to the anterior portion of the rail or skate and the other one on the posterior portion of the skate.

This further possible configuration allows to study load distribution on the lateral-anterior, medial-anterior, lateral posterior and medial-posterior areas of the foot during the standing as well as gait cycle. This analysis may include counting of the number of steps with certain proscribed amount of load on the certain areas of the foot.

Furthermore, the system guarantees the possibility for the surgeon to remotely monitor the correct execution of the medical prescription, for example by assessing the ignored feedback, being able to intervene in a timely manner, changing the protocol and/or making contact with the patient for optimize the recovery process.

In another possible configuration, shown in the examples of theFIGS.5and5A, a fixation system100′ of the present disclosure includes the envelope box60located in the middle of each skate20.

Distance measuring sensors63(e.g., ultrasound-based sensors or proximity sensors) are attached to the front of the rails allowing to avoid interference (impact) with surrounded objects (e.g., wall) at the certain predetermined distance by sending a visible or hearable signal (e.g., audible signal). This will be beneficial in patients with significantly reduced or absent sensitivity on the foot (e.g., Charcot disease patients).

In addition, similar sensors65can be attached on the outside surface of the envelope60that is to say at the lateral portion of the rail to produce even better control on surrounding objects.

In another possible configuration, shown inFIG.6, a fixation system100″ includes a proximity sensors63interfaced with small lights61at the front of the rails. Those sensors63are electrically coupled to the electronic controller50and can turn-on those interfaced lights61automatically e.g., at dark areas or at dusk. Working as small flashlights, those lights61can significantly improve visibility of the objects in the front of the patients again to avoid toes impact with those surrounding objects.

In another possible configuration, the system100′ or100″ includes shock absorbing or damping mechanisms to lessen the impact forces on the bone-wire of bone-pin interface. This may be accomplished by the addition of shock absorbing material, e.g. the cover35on the bottom of the rails, while the use of an alternative mechanical components such as central dumping spring33disclosed with reference toFIG.6(or other dynamization modules located between the rails and the foot plate) would require a particular care to calibrate the response of those elements.

As can be understood from the above description, the system according to the present disclosure may be configured to combine the different embodiments disclosed in the figures and is able to meet the requirements and overcome the drawbacks mentioned above in the introductory part of the present description with reference to the prior art.

It will be understood that embodiments described herein are shown by way of illustration and not as limitations of the invention and can be combined to obtain different possible configurations falling under the scope of the enclosed claims. The principal features of this invention can be employed in various embodiments without departing from the scope of the invention. Those skilled in the art will recognize or be able to ascertain using no more than routine experimentation, numerous equivalents to the specific procedures described herein. Such equivalents are considered within the scope of this invention and are covered by the claims.

All publications and patent applications mentioned in the specification are indicative of the level of skill of those skilled in the art to which this invention pertains. All publications and patent applications are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.

The use of the word “a” or “an” when used in conjunction with the term “comprising” in the claims and/or the specification may mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.” The use of the term “or” in the claims is used to mean “and/or” unless explicitly indicated to refer to alternatives only or the alternatives are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and “and/or.” Throughout this application, the term “about” or “substantially” is used to indicate that a value includes the inherent variation of error for the device, the method being employed to determine the value, or the variation that exists among the study subjects.

As used in this specification and claim(s), the words “comprising” (and any form of comprising, such as “comprise” and “comprises”), “having” (and any form of having, such as “have” and “has”), “including” (and any form of including, such as “includes” and “include”) or “containing” (and any form of containing, such as “contains” and “contain”) are inclusive or open-ended and do not exclude additional, unrecited elements or method steps. It should be appreciated that the present application provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the fixation device disclosed herein and do not delimit the scope of the application, and their usage does not delimit the application, except as outlined in the claims.

Obviously a person skilled in the art, in order to satisfy any specific requirements which might arise, may make numerous modifications and variations to the invention described above, all of which are contained moreover within the scope of protection of the invention, as defined by the following claims.