METHOD OF TREATMENT OF PRESSURE SORES

FIELD OF THE INVENTION

The present invention relates to the field of medical treatment and, more particularly, to a method of treating pressure sores using subcutaneous implants.

BACKGROUND OF THE INVENTION

It is well known that patients who remain in bed or chairs for extended periods of time can develop pressure sores, also known as decubitus ulcers, decubiti, or bed sores, due to prolonged pressure on the skin causing circulatory restriction. Most people do not normally develop pressure sores because they constantly shift position without thinking, even when asleep. However, some people are incapable of normal movement and are therefore at high risk of developing pressure sores. This group includes people who are paralyzed, comatose, very weak, or restrained. Paralyzed and comatose people are at particular risk because they may be unable to sense discomfort or pain, signals that normally motivate people to move or to ask to be moved.

The skin has a rich blood supply that delivers oxygen to all its layers. If that blood supply is cut off for more than 2 or 3 hours, the skin dies, beginning at its outer layer (the epidermis). The dead skin breaks down and forms an open sore or ulcer. Once the skin is broken, bacteria may enter the opening and cause an infection.

Skin damage from pressure usually begins over bony prominences i.e. any place on the body where the bones are close to the skin surface. Bony prominences tend to put pressure on the skin from within. If there is also a firm surface on the outside, the skin will be pinched between the firm inside bone and the firm outside surface, resulting in a lack of circulation.

Pressure sores are most common on the heels and on the hips. Other areas at risk for pressure sores include the base of the spine, the shoulder blades, the backs and sides of the knees, and the back of the head.

The first sign of a pressure sore is a reddened area of the skin, which fades within 15 minutes after the pressure is removed. A continued lack of blood flow, and resultant lack of oxygen, cause cells to die and eventually cause the sores.

The time-frame for occurrence of these sores depends on various factors such as the firmness and friction of the surface against the patient's skin, temperature, moisture, and the health and susceptibility of the skin due to age or illness. A pressure sore may require several weeks, or even several months, of hospitalization or bed rest in order to heal.

Pressure sores may also occur as a result of bruises or scrapes, prolonged wetness on the skin (such as due to perspiration, stool or urine), burns (such as from heat, friction or chemicals), and frostbite. Pressure sores are more apt to occur after spinal cord injury due to lack of movement and sensation and to changes in circulation. Following spinal cord injury, the natural healing ability of the body is reduced, and pressure tolerance is decreased. The body of the patient is able to tolerate a small amount of pressure for a long time, but can only tolerate great pressure for a short time before the circulatory system is disrupted and a pressure or skin sore results. The decrease in circulation and lower tolerance for pressure is further aggravated by the lack of sensation after spinal cord injury, such that the patient may be unaware that a part of the body is under duress.

Due to the decrease in the rate of circulation that occurs following spinal cord injury, there is also less oxygen to the skin. This contributes to a lowering of the skin's resistance. If the skin is deprived of oxygen due to pressure, the body will try to compensate by sending more blood to the area. This may result in swelling, which will put even further pressure on the blood vessels and further block circulation.

Pressure sores are categorised into four key stages depending on their age and severity. In the first stage, the skin is not broken but is red or discoloured. The redness or change in colour does not fade within 30 minutes after pressure is removed. In the second stage, the epidermis is broken, creating a shallow open sore. Drainage may or may not be present. In the third stage, the break in the skin extends through the dermis into the subcutaneous and fat tissue. The wound is deeper than in

Stage Two. In the fourth stage, the breakdown extends into the muscle and can extend as far down as the bone. Usually lots of dead tissue and drainage are present.

Complications of pressure sores include cellulitis (which can also lead to sepsis and meningitis); bone and joint infections (resulting in damage to cartilage and tissue, and to bone death, causing reduced function of the joints and limbs), such as osteomyelitis; the life-threatening infection necrotizing fasciitis; myonecrosis (a severe form of gangrene, causing potentially fatal systemic problems); sepsis (a life- threatening condition causing shock and organ failure); autonomic dysreflexia; bladder distension; pyarthroses; amyloidosis; anemia; urethral fistula; and very rarely malignant transformations .

In order to allow blood to flow to the areas of restriction, the position of immobile patients must be changed regularly (about every 2 hours) by nursing or hospital personnel to reduce the occurrence of pressure sores. Frequent repositioning of the patient is not always possible, especially if the patient is not in a facility that provides such services.

Alternatively, the occurrence of pressure sores may be reduced by use of devices comprising support systems, such as mattresses, cushions, or pads, that are intended to more evenly redistribute the pressure under bony prominences, together with repositioning. Support systems include air-filled alternating-pressure mattresses, sponge rubber, silicone gel or water mattresses. Protective padding (such as sheepskin or a synthetic equivalent) at bony prominences may also be required.

A number of disadvantages are associated with such devices. For example, the device must be transferred to any location in which the patient is to be situated for any significant time period, which is obviously difficult in the case of a bulky and/or heavy mattress. Air or water-filled support systems are susceptible to physical damage, such as by puncturing. Cushions or pads may be misplaced by a senile patient, or by careless hospital staff or other caregivers. Furthermore, scrupulous cleanliness of the device is required to prevent maceration and secondary infection of the sore, which is particularly problematic in the case of incontinent patients. There is thus a widely recognized need for, and it would be highly advantageous to have, a method of preventing or reducing the occurrence of pressure sores, devoid of at least some of the above limitations.

SUMMARY OF THE INVENTION

According to one aspect of the present invention there is provided a method of treating a pressure sore in a patient in need thereof, comprising inserting a biocompatible subcutaneous implant under at least one skin layer at a bony prominence thereby redistributing pressure exerted on the skin of the patient by said bony prominence.

According to preferred embodiments, "treating" may optionally comprise one or more of preventing, ameliorating, reducing, alleviating, eliminating (partially or completely) or relieving. The bony prominence may be, for example and without limitation, a heel, a hip bone, the base of the spine, a shoulder blade, the side of a knee and the back of the head.

The skin layer may optionally comprise any layer of skin, including but not limited to one or more of an epidermis, a dermis, and a subcutaneous layer. The implant may be inserted under a connective tissue layer, a fascia, a muscle or against any bony prominence.

According to further features in embodiments of the present invention, an implant inserted by surgical insertion optionally and preferably comprises at least a first lumen filled with a first support material. Optionally and preferably, the support material is selected from the group consisting of a solid, a liquid, a semi solid, a gel, a colloid, a suspension, an emulsion, a gas, or a supercritical fluid. The implant may further optionally comprise a second lumen, optionally and preferably filled with a second material consisting of a liquid, a semi solid or a gel. The first and second materials may be the same or different. The liquid may comprise, for example, saline, which may optionally be filled into the first or the second lumen either before or after surgical insertion of the implant. The gel may comprise, for example, silicone gel.

According to yet further features in embodiments of the present invention, an implant inserted by surgical insertion may comprise at least one of expanded polytetrafluoroethylene and carvable solid silicone elastomer.

According to yet further features in embodiments of the present invention, a method comprising surgical insertion comprises performing an incision in the skin. The method optionally further comprises administering a local anaesthetic prior to

performing the incision, following with the implant is inserted through the incision.

The method further optionally comprises sealing the incision after inserting the implant.

According to further features in embodiments of the present invention, an implant inserted by injection may comprise at least one of silicone gel, collagen (such as donor collagen, auto-collagen, bovine-derived collagen, and bioengineered human collagen), artecoll, fascia, fat, putty-like radio-opaque polyrnethymethacrylate cement, and a hyaluronic acid-based filler.

Silicone gel used in any of the embodiments of the present invention may optionally be either biodegradable or non-biodegradable. Preferably, nonbiodegradable silicone gel is used for treatment of a patient suffering from an irreversible immobility; and biodegradable silicone is used for treatment of a patient suffering from a reversible immobility.

Biodegradable silicone optionally comprises porous silicone. The porous silicone may optionally further be configured for subcutaneous delivery of an active pharmaceutical substance.

Pharmaceutical substances for use in any of the embodiments of the method of the present invention, include, for example, a substance for the treatment of a complication of pressure sores, including, for example, cellulitis, sepsis, meningitis, bone and joint infections, fasciitis, myonecrosis, autonomic dysreflexia, pyarthroses, amyloidosis, anemia, urethral fistula and cancer. Non-limiting examples of suitable pharmaceutical substances in accordance with the method of the present invention include analgesics, antibacterials, antibiotics, antidepressants, antihistamines, antihelminths, antiinflammatory agents, antiirritants, antilipemics, antimicrobials, antimycotics, antioxidants, antipruritics, antiseptic, antiswelling agents, antiviral agents, astringents, topical cardiovascular agents, chemotherapeutic agents, corticosteroids, fungicides, hormones, hydroxyacids, lactams, non-steroidal antiinflammatory agents, progestins, sanatives and vasodilators and mixtures thereof.

The method of the present invention may optionally further comprise monitoring of the patient for indications of susceptibility to pressure sores, such as for example, immobility of the patient or the appearance of areas of reddening of the skin in the area of at least one bony prominence. Monitoring may also comprise monitoring for an indication of susceptibility of a patient to at least a second pressure sore,

indicated by the appearance of a first pressure sore. Monitoring may comprise, for example, visual inspection, electronic monitoring, monitoring of oxygen level, temperature measurement, use of inflammation markers, or use of biochemical markers. The method of the present invention may further comprise detection of an indication of susceptibility of a patient to a pressure sore.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.

In the drawings:

FIG. 1 is an illustration of the areas of bony prominence, FIG. 2 is an illustration of an implant inserted at an area of bony prominence; FIGS. 3a-3b illustrate examples of implants for use in an embodiment of the method of the present invention;

FIG. 4 presents a schematic representation of an embodiment of the method of the present invention; and

FIG. 5 is an illustration of a hydraulic delivery device for putty-like radio- opaque polymethymethacrylate cement.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is of a method of treating pressure sores which may develop in an immobile patient due to prolonged pressure exerted on the skin of the patient.

The method comprises subcutaneous insertion of a biocompatible implant between the skin of the patient and a bony prominence, thereby redistributing pressure exerted on the skin by the bony prominence.

As used herein the term "treating" is intended to include treating, curing, abrogating or preventing pressure sores.

As used herein, the term "bony prominence" refers to an area of the body at which a bone is prominent. In a patient having a low level of "padding" of fatty tissue or muscle at the site of a bony prominence, external pressure exerted on the skin overlying the bony prominence, such as when the patient sits or lies on a solid surface, causes the skin to be compressed between the solid surface and the prominent bone.

The implant is positioned over at least a portion of the surface of the bony prominence, between the bony prominence itself and the skin which overlies the bony prominence, particularly over the portion of the bony prominence which is in contact with the skin and gives rise to pressure sores.

Optionally, the implant surrounds at least a portion of the bony prominence, including areas which are not in contact with the skin. An implant for surrounding the bony prominence may be provided, for example, in the shape of a 'U', or in the shape of a ring. Such an implant distributes the pressure over a wider area than one which only covers the contact point between the bony prominence and the skin, thereby substantially preventing the occurrence of pressure sores.

Figure 1 illustrates the areas of bony prominence, which are most susceptible to the development of pressure sores in an immobile patient. As can be seen in the

Figure, such areas include, for example, the elbow 10, the inner knees 12, the back of the head 14, the shoulder blades 16, the base of the spine and buttocks 18, heels 20, and the hips 22.

As used herein, the term "implant" refers to any biocompatible material which may be inserted between the skin of the patient and a bony prominence, and which alleviates localized pressure at the site by redistributing over a wider area the force exerted on the skin by the bony prominence. The principles of a method of treating pressure sores according to the present invention may be better understood with reference to the drawings and accompanying descriptions.

Suitable implants are known and shown in the art. For example, implants currently used for breast enlargement, gum augmentation, testicular implants, penile implants, or for filling defects such as those due to birth defects or burn damage are suitable. These include surgically insertable implants and injectable implants.

Surgical implants are preferably inserted following administration of a local anaesthetic, via a minimal incision made in the surface of the skin at an appropriate distance from the surface of the bony prominence. Undermining is then performed i.e. separation of the skin of the epidermal-dermal layer from the underlying tissue layers, in order to form a pocket for implant placement. Following insertion of the implant, the incision is closed, optionally and preferably by stitching, using either degradable or non-degradable thread.

Surgically insertable implants may comprise sacs which are filled with a support material, either before or after implantation of the sac into the body of the recipient. U-shaped or ring-shaped implants are preferably filled after implantation of the sac.

The support material may optionally comprise a solid, a liquid (such as saline), a gel (such as silicone gel), a semi solid, a colloid, a suspension, an emulsion, a gas, or a supercritical fluid. The sac may optionally be impregnated with an active pharmaceutical substance. Anchoring of the implant at the required location is generally not required, due to the discrete anatomical locations at which the implant is positioned. However, particularly in the case of a deep tissue, anchoring may be required. The anchoring may comprise, for example, stitching, "soldering" closed the edges of the pocket in which the insert is inserted, or gluing with a biocompatible glue

(such as an acrylic glue). The implant may optionally be provided with a silicone elastomer tab that enables implant to be sutures and secured into a set position, if this is desired.

Saline-filled implants preferably comprise a silicone sac that is inflated with a sterile saline solution, and may comprise a single lumen that is implanted into the body then filled with a volume of saline through a valve. The implant may optionally further comprise a detachable reservoir, through which saline is inserted following implantation of the sac, and which is removed once filling of the lumen is complete. As an alternative option, the implant may comprise a self-sealing injection site through which saline is filled into the implant.

Alternatively, the lumen may be pre-filled with a volume of saline prior to implantation. Saline-filled implants are optionally inserted endoscopically. Saline- filled implants have the advantage that if rupture of the outer lumen occurs, released saline is absorbed naturally by the body.

Silicone gel-filled implants may comprise, for example, a single lumen that is pre-filled with a fixed volume of silicone gel; a double lumen (one inside another) wherein the inner shell is pre-filled with a fixed volume of silicone gel and the outer lumen is filled with saline after placement in the body; a double lumen wherein the outer shell is pre-filled with a fixed volume of saline and the inner lumen is filled with saline after placement in the body; or a double lumen wherein the outer lumen is pre- filled with silicone gel and the inner lumen is filled with a gas, such as carbon dioxide, after placement in the body . In most patients, a fibrous capsule forms around the implant (ie, encapsulation). The capsule may be soft and nonpalpable or hard and resistant. When silicone-gel filled implants are used, rupturing may occur, which may be intracapsular rupture (such that occurs when silicone escapes the silicone sac but is contained in the fibrous capsule), or extracapsular (such that rupture involves the escape of free silicone gel through the fibrous capsule).

Gas-filled implants may optionally comprise an expandable sac, consisting of rubber or a similarly extendible material, into which gas is filled, either before or after subcutaneous insertion. Such an expandable sac is preferably further provided with a filling port and detachable filling tube. The gas may optionally comprise carbon dioxide. Alternatively, the gas may comprise hydrogen, helium, or a combination thereof.

Supercritical fluid filled implants may comprise, for example, carbon dioxide, compressed at high temperature and high pressure to form a supercritical fluid, which

has a state between that of a gas and a liquid. Carbon dioxide-containing implants may optionally comprise a sac comprising polymethylmethacrylate.

Alternatively, surgically insertable implants may comprise Goretex implants, made of plastic, expanded polytetrafluoroethylene (ePTFE), which are inserted through a small incision; or carvable solid silicone elastomer, which may be carved to a required shape.

Any of the fluid-filled implants described above may comprise two or more compartments in fluid communication with each other, such that transfer of fluid between compartments may occur. Transfer of fluid may occur, for example, in direct response to the exertion of pressure on one or more compartments, such that more even distribution of pressure is provided than in a single-compartment implant. The fluid may pass from one compartment to another, for example, via an open-ended fluid port, such as a tube. Alternatively, the fluid transfer may be controlled, for example, by the use of pressure-responsive valves. Preferably, fluid transfer is reversible, such that the amount of fluid in each compartment is adjusted and readjusted according to the amount of pressure exerted by a particular region of a bony prominence.

Alternatively, fluid transfer between compartments may be controlled externally, such as by use of a remotely-controlled device provided within the implant, which opens and closes a valve.

Optionally the fluid filled implant described above may further comprise a pressure sensor, optionally and preferably in the form of a Micro Electro-Mechanical Systems (MEMS) pressure sensor; however any implantable small pressure sensor may be used. Optionally a plurality of compartments may comprise a pressure sensor, optionally comprising an array of pressure sensors within the implant. Optionally a plurality of pressure sensors may be differentially arranged within the implant, for example optionally and preferably providing a region that is more sensitive to pressure fluctuations.

When the pressure sensor detects a change in pressure in the implant of the present invention, the pressure sensor preferably produces an electric current. The resultant electric current may then be used to optionally and preferably alter the implant characteristics to apply a counteracting force against the pressure and hence to overcome the change in pressure. For example, a pressure sensor integrated into the

implant of the present invention preferably detects an increase in pressure over a particular region of the implant, thereby producing an electric current. The electric current then causes a change in the properties of the fluid injectable material within the implant, preferably with respect to the fluid's resistance or viscosity. The change in resistance or viscosity within the implant is preferably proportional to the change in pressure in the region where a change in pressure has been detected, thereby preferably overcoming the change in pressure with a counteracting force.

Optionally and preferably the implant of the present invention may further comprise a motor, more preferably in the form of a MEMS motor. Optionally and more preferably, the motor may act in connection with the pressure sensor to drive the injectable fluid material of the implant of the present invention in response to the sensed change in pressure. For example, when a pressure change is sensed by the pressure sensor, it optionally drives a motor which then acts on the implanted material to compensate for the change in pressure. The motor may optionally compensate for the change in pressure by opening a pressure valve, or moving compartments of implanted material to an area of need. Optionally the motor may act to produce an electric current to change the resistance properties of the implanted material.

Optionally and preferably the implant of the present invention may further comprise a processor and one or more components for wireless communication. Optionally, the sensor may be associated with such a processor and one or more components for wireless communication including but not limited to Bluetooth, IrDA protocol and/or any type of optical communication means. A sensed pressure change optionally and preferably produces an electric current which optionally and preferably causes the wireless communication component(s) to communicate with an external device for example including but not limited to a mobile phone, PDA, computer or the like, to communicate or display the change in pressure within the implant. Optionally and preferably the pressure distribution may then be mapped by the external device, for example optionally providing a method for gauging pressure changes within the implant. Optionally, based on the change in the pressure distribution, the implant may be changed or more material injected to compensate for the displayed pressure distribution.

Optionally and preferably the external device, including but not limited to a mobile phone, PDA and/or a computer, may communicate with one or more

components for wireless communication to control any one of the motor or processor in order to control the injectable fluid material distribution within the implant to compensate or control the pressure distribution.

Optionally and preferably the components comprising the implant of the present invention may be used independently or in any combination to produce an electric current that may optionally and preferably be used to apply an electric current to the pressure sore to preferably generate wound healing processes of the wound tissue. Optionally the processor may control the properties of the current used while optionally the motor may be used to generate sufficient current, while optionally the pressure sensor may be used to identify the location requiring treatment.

Injectable materials include silicone gel, collagen (for example, bovine-derived collagen, auto-collagen i.e. collagen extracted from a different location in the body of the patient, collagen extracted from deceased human donors, or bioengineered human collagen); artecoll (a synthetic filler material); fascia (a specific type of connective tissue, harvested from the patient's body or form a deceased human donor); fat (such as from the thighs or abdomen of the patient); putty-like radio-opaque polymethylmethacrylate cement or a hyaluronic acid-based filler (such as HylaForm™ or restylane™). The injectable material is inserted by subcutanous injection at an appropriate distance from the site of the bony prominence, preferably with the needle inserted substantially parallel to the surface of the overlying skin. The amount of injectable material required is dependant upon the surface area of the bony prominence which exerts pressure on the skin, which is itself a factor of the particular bony prominence which is responsible for causing a pressure sore, as well as on the height of the patient. The required amount may easily be calculated by a person skilled in the relevant art.

Putty-like radio -opaque polymethymethacrylate cement may be administered by a hydraulic delivery system, such as that produced by Disc-O-Tech Medical Technologies Ltd., Herzliya, Israel. The delivery system provides directional cement introduction through a beveled tip or a side-firing introducer needle. The cement is delivered in an immediate putty-like phase, with no liquid phase, thereby enabling delivery of the cement to be accurately controlled, with no leakage of liquid beyond the desired delivery site.

As used herein, the term "radio-opaque" means a material which is not transparent to x-rays or other forms of radiation.

Silicone gel used in any of the embodiments of the method of the present invention may optionally be porous silicone (such as that produced by pSiMedica, UK), which has been found to be biodegradable in vitro (L.T. Canham: Properties of porous silicone, IEE EMIS Datareview No. 18, IEE publications, Stevenage). Non- porous silicone may be converted into porous silicone by etching nanometer-sized pores into the silicone surface using hydrofluoric-acid based solutions. The "porosity" (the fraction of the total volume that is void) can be varied, for example by selection of electrolyte composition and applied current density. Use of a biodegradable implant is beneficial for the treatment of a temporarily immobile patient, avoiding the requirement for surgical removal of the implant when no longer required as the patient regains mobility. The rate of degradation of the silicone can be controlled, according to the estimated period over which it is expected that the implant will be required, by varying the level of porosity, since it has been found that highly porous silicone degrades faster than lightly porous silicone.

A further advantage of porous silicone for the purpose of the present invention is that it is able to anchor itself to bone, such that it remains securely in place. Furthermore, the elasticity of the silicone implant can be adjusted by varying the level of porosity to match that of the bone. This avoids the problem of "stress shielding" which occurs with an implant which takes all the load, causing nearby healthy bone to die, since bone is a tissue which thrives on stress.

For chronically immobile patients, non-porous, non-degradable silicone is preferred, such that degradation and consequent replacement of the implant is minimized.

Optionally, a biodegradable silicone implant may further serve as a "scaffold" that encapsulates an active pharmaceutical substance, such as, for example, an antibiotic to prevent bone infection at the pressure site. The active substance may, for example, be in a liquid form which is initially drawn into the porous silicone by capillary action, and be gradually released as the surface of the silicone scaffold erodes within the body. The rate of release of the drug from the porous silicone can itself be controlled by varying the level of porosity in the silicone. The rate of release can also be controlled by derivitizing the surface of the porous silicone, i.e. by replacing the

hydrogen atoms at the end of the silicone skeleton with other groups, such as amino acids or hydrophilic chains of carbon atoms.

An active pharmaceutical substance for use in any of the embodiments of the present invention may be, for example, a substance for the treatment of a complication of pressure sores, such as an agent for the treatment of cellulitis, sepsis, meningitis, bone and joint infections (such as osteomyelitis), fasciitis, myonecrosis, autonomic dysreflexia, pyarthroses, amyloidosis, anemia, urethral fistula or cancer.

Suitable active substances for use in any of the embodiments of the present invention include topical or systemically active substances. Non-limiting examples of suitable substances include analgesics, antibacterials, antibiotics, antidepressants, antihistamines, antihelminths, antiinflammatory agents, antiirritants, antilipemics, antimicrobials, antimycotics, antioxidants, antipruritics, antiseptic, antiswelling agents, antiviral agents, astringents, topical cardiovascular agents, chemotherapeutic agents, corticosteroids, fungicides, hormones, hydroxyacids, lactams, non-steroidal anti-inflammatory agents, progestins, sanatives and vasodilators and mixtures thereof.

The method of the present invention may optionally further comprise monitoring of the patient for indications of susceptibility to pressure sores. For example, immobility of the patient may be considered as a sufficient indication of susceptibility, without the requirement for further monitoring, such that an implant is inserted into an immobile patient prior to the appearance of any signs of development of a pressure sore. Alternatively, monitoring may comprise monitoring for the appearance of areas of reddening of the skin in the area of at least one bony prominence. Monitoring may also comprise monitoring for an indication of susceptibility to at least a second pressure sore, indicated by the appearance of a first pressure sore, either in the vicinity of the same bony prominence or in a different area. Monitoring may comprise, for example, visual inspection, electronic monitoring, monitoring of oxygen level, temperature measurement, use of inflammation markers, or use of biochemical markers. The method of the present invention may further comprise detection of an indication of susceptibility to a pressure sore.

Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details set forth in

the following description or exemplified by the Examples. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting. As used herein the term "about" refers to ± 10 %.

Referring now to Figure 2a, there is shown an implant 30 inserted into an elbow 32 of a patient, in accordance with an embodiment of the method of the present invention. As shown in Figure 2a, implant 30 is positioned between the olecranon process of the ulna 34 (the bony prominence at the very tip of the elbow) and the skin 36 covering the olecranon process 34. Alternatively, the implant may be inserted between the skin of the patient and a bony prominence including but not limited to a heel, a hip bone, the base of the spine, a shoulder blade, the side of a knee and the back of the head.

Figure 2b shows an implant 40, such as a U-shaped or ring-shaped implant, which is inserted into elbow 32 of a patient, and positioned beneath the skin 36 covering the olecranon process 34, so as to at least partially extend around the olecranon process of the ulna 34.

Figures 3a-b illustrate an exemplary implant 50 for use in an embodiment of the method of the present invention. Implant 50 comprises a sac 52 having a fill port 54. Silicone gel or saline is optionally filled into sac 52 via port 54 prior to insertion of sac 52 into the body, such that implant 50 is inflated to the required dimension. Port 54 is then closed, and may be further sealed, for example by a biocompatible adhesive patch (not shown).

Alternatively, sac 52 may be subcutaneously implanted prior to filling, and subsequently filled with saline following implantation. As shown in Figure 3b, a post- insertion implant 50 may optionally further comprise a detachable fill tube 56 and reservoir 58, which are removed following completion of filling. Fill port 54 is then sealed with a valve (not shown), such as a leaf valve, a kink valve or a diaphragm valve. Figure 4 presents a diagrammatic representation of an optional but preferred embodiment of an exemplary method of the present invention. A bedridden and immobile patient, such as one suffering from spinal cord injury is regularly monitored in stage 60 for the appearance of early signs of pressure sores, detectable as areas of

reddened skin. Following detection in stage 62 of a severely reddened area on the surface of the skin in the vicinity of a bony prominence, a local anaesthetic is administered in sta'ge 64 in the vicinity of the reddened area, and a minimal surgical incision in stage 66 is made in the surface of the skin at an appropriate distance from the bony prominence. An implant, such as a pre-fϊlled silicone gel implant is inserted in stage 68 through the incision. The incision is then closed in stage 70, such as by stitching. Following insertion of the implant, force originating from pressure against the shoulder blade bone is distributed over the entire area of the insert, resulting in less pressure at any given point. Alternatively, stages 64-70 may optionally be performed to substantially prevent the appearance of bedsores, optionally even without monitoring and/or before monitoring detects a sign of a pressure sore.

According to preferred embodiments of the present invention, a material such as a putty-like cement may optionally be used in addition to or in place of the above describe implant material.

Figure 5 shows an exemplary, illustrative hydraulic delivery system 80 for introduction of putty-like radio-opaque polymethymethacrylate cement into the body of a patient. The system comprises an introducer needle 82, a reservoir 84 containing the cement, a water reservoir 86 containing sterile water, and an extension tube 88.

Additional objects, advantages, and novel features of the present invention will become apparent to one ordinarily skilled in the art upon examination of the following examples, which are not intended to be limiting. Additionally, each of the various embodiments and aspects of the present invention as delineated hereinabove and as claimed in the claims section below finds experimental support in the following examples.

It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination.

Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention.