Abstract:
A debridement method, device and system or kit are effectively used to debride a lesion, particularly an osteolytic lesion resulting from a hip or knee arthroplasty. In the lesion treatment, an effective amount of a debridement fluid with suspended particulate abrasive is delivered to a lesion area within body tissue to debride the lesion; and the fluid is intermittently aspirated from the area.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The invention relates to a method, device and kit for washing and debridement of a lesion. More particularly, the invention relates to an irrigation method, device and kit for debridement of an osteolytic lesion.  
         [0002]     Osteolysis is a common complication in total hip arthroplasty and a common cause of component failure. Osteolysis is a response to wear debris. It can develop around a hip or knee implant as a result of the presence of bearing surface wear debris, access of wear debris particles to an implant-bone interface and a biologic osteolytic response of a host bone to debris laden synovial or other physiological fluids to the wear particles. Osteolysis is mediated primarily by macrophages. Fibroblasts and endothelial cells also play a role. These cells are activated by the bearing surface wear debris, primarily polyethylene, but also metal and polymethylmethacrylate particles. The biologic reaction to these particles is a nonspecific foreign-body reaction. Particles in the submicron size range undergo phagocytosis by macrophages and release a variety of cytokines which ultimately stimulate osteoclasts to resorb bone. The most common source of wear debris is adhesive-abrasive wear between a femoral head and polyethylene liner. This wear can produce as many as 500,000 particles per gait cycle.  
         [0003]     Osteolysis can be asymptomatic until the lesions become very large. While some osteolytic lesions may be cleansed by washing and conventional debridement, surgery is a typical treatment. The surgery both treats the lesions and removes particles with attendant biofilm that could generate recurrence. With a stable acetabular component in acceptable alignment and with a modular liner, debridement and bone grafting of the lesions with retention of the acetabular shell and replacement of the polyethylene liner can be successful. However, if the acetabular shell is loose or malpositioned, then revision of the component is indicated.  
         [0004]     While washing and debridement procedures are preferred approaches to lesion management, these less invasive procedures are not uniformly successful. Lesions can be difficult to debride, particularly osteolytic lesions. Osteolytic lesions are often located in tortuous and remote anatomy that is difficult to access using traditional instruments and these lesions are often filled with obstructing bony spicules, gelatinous masses of necrotic and fibrous tissue. This tissue can be adherent or non-adherent to surrounding intact tissue that defines the border of the lesion.  
         [0005]     There is a need for an improved debridement method for osteolytic bone lesions that is minimally invasive and that does not require removal of a well-fixed previous implant. There is a need for a debridement method to effectively debride lesions in difficult anatomic locations and a need for a method to effectively break up soft tissue, clean the lesion edge and evacuate lesions that result with hip or knee implant procedures. There is a need for a device capable of breaking up the soft tissue, cleaning the lesion edge, removing the biofilms and evacuating the area through a substantially non-evasive arthroscopic methodology.  
       BRIEF DESCRIPTION OF THE INVENTION  
       [0006]     The invention relates to a debridement method, device and system or kit to effectively debride a lesion, particularly an osteolytic lesion resulting from a hip or knee arthroplasty. According to the invention, a method for treatment of a lesion, comprises: delivering an effective amount of a debridement fluid with suspended particulate abrasive to a lesion area within body tissue to debride the lesion; and intermittently aspirating the fluid from the area.  
         [0007]     In an embodiment, the invention is a method for removing unwanted material from a body cavity comprising: providing a fluid reservoir with abrasive particle-containing debridement fluid and a device comprising a tubular flexible line having a pickup end and an delivery/aspirator end, an inner cannula and an outer second cannula that extend concentric with one another longitudinally as part of the tubular flexible line; the inner cannula having at least one orifice at the delivery/aspirator end of the tubular flexible line to deliver the debridement fluid with suspended particulate abrasive from the fluid reservoir to a lesion area in need of debridement; and the outer cannula substantially open at the delivery/aspirator end of the tubular flexible line to aspirate fluid from the area; and delivering an effective amount of a debridement fluid with suspended particulate abrasive from the reservoir by the inner cannula into the lesion area to debride the lesion; and aspirating fluid from the area by the outer cannula.  
         [0008]     Another embodiment comprises a device for treatment of an osteolytic lesion, comprising: a fluid reservoir; abrasive particle-containing debridement fluid contained within the fluid reservoir; and a tubular conduit having a pickup end and delivery/aspirator end; an inner cannula and an outer cannula extending concentric to one another longitudinally as part of the tubular conduit, the inner cannula having at least one orifice at the delivery/aspirator end of the tubular conduit to deliver or aspirate debridement fluid with suspended particulate abrasive to or from a lesion area in need of debridement; and the outer cannula substantially open at the delivery/aspirator end of the tubular flexible line to deliver or aspirate fluid from the area.  
         [0009]     In yet another embodiment, the invention is a kit or system for treatment of a lesion, comprising: a fluid reservoir; abrasive particle-containing debridement fluid contained within the fluid reservoir; a tubular conduit having a pickup end and delivery/aspirator end an inner cannula and an outer cannula, extending concentric to one another longitudinally as part of the tubular conduit; the inner cannula having at least one orifice at the delivery/aspirator end of the tubular conduit to deliver debridement fluid with suspended particulate abrasive from the fluid reservoir to a lesion area in need of debridement; and the outer cannula substantially open at the delivery/aspirator end of the tubular flexible line to aspirate fluid from the area; and an imaging device to monitor delivery of the debridement fluid to the lesion area and aspiration of fluid from the area. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]      FIG. 1  is a schematic elevation of a lesion debridement device;  
         [0011]      FIG. 2  is a cross-sectional side view of a tubular flexible delivery tube end of the  FIG. 1  device;  
         [0012]      FIG. 3  is a schematic side elevation of a pulse-generating mechanism for the debridement device;  
         [0013]      FIG. 4  is a schematic perspective view of a user using a system or kit including a lesion debridement device and monitoring fluoroscope; and  
         [0014]      FIG. 5  shows a hip joint in need of treatment for a lesion and placement of a debridement device to effect irrigation of the lesion 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0015]     In the invention, a lesion is irrigated with a fluid with suspended particulate abrasive by an irrigation process, preferably by pulse irrigation (also called “pulse lavage”).  
         [0016]     Pulse lavage or pulse irrigation is one procedure for wound and lesion management. In this procedure, pulsating water is directed toward the wound or lesion area. This procedure is effective in removing debris and bacteria from wound and lesion areas. Pulse irrigation is used as part of a number of orthopedic procedures such as prosthetic joint replacement, in which it is used to remove bone fragments from an area of prosthesis. A controllable pulsating stream of liquid to a wound or lesion can provide a therapeutic action that promotes healing and decreases infection.  
         [0017]     Various fluids are used with lavage or irrigation procedures to induce proper healing. In McCarthy U.S. Pat. No. 3,288,140, for example a method and apparatus for treatment of surface wounds by fluids is disclosed. Saline is the McCarthy preferred fluid. Further, Vad U.S. Pat. No. 6,527,760 uses normal saline in combination with an antibiotic  
         [0018]     The debridement fluid of the invention can be water and other aqueous compositions, including any other typical irrigating or debridement solution. Preferably the fluid is a clear biocompatible debridement fluid such as warm isotonic saline or normal saline in combination with an antibiotic. However, many variations are possible. The solution may include buffers and a bicarbonate, citric acid and tanic acid in very low concentrations. Or the fluid can be a gas and liquid mixture. The gas can be oxygen or carbon dioxide or hydrogen peroxide useful for sterilization purposes. The fluid can include steroid and anti-inflammatory medicaments.  
         [0019]     A preferred debridement fluid comprises a mixture of inorganic salts and, optionally minerals, compounded to mimic an electrolyte concentration and a body fluid mixture in an isotonic state. The fluid typically comprises a halide salt of lithium, sodium, potassium, calcium, and other cations. Typically the halide is fluoride, chloride, bromide, or iodide, and most typically chloride. A typical electrolyzed solution of the present invention has a pH within the range of about 2 to about 5, an oxidation reduction potential within the range of about +600 mV to about +1200 mV, and hypohalous acid concentration in the range of about 10 ppm to about 200 ppm. The solution can have bactericidal, fungicidal, and sporicidal properties.  
         [0020]     The particulate abrasive can be a biosorable material, which preferably dissolves within several days. Preferably, the abrasive is resorbable and capable of passing through small gauge needles under lavage pressure. Calcium sulfate (CaSO 4 ) is a preferred material. The particulate abrasive can be present in the debridement fluid in a percent by weight between 0.1% and 65%; desirably between 1% and 40% and preferably between 3% and 15%.  
         [0021]     Other possible bioabsorbable materials can be injectable solid forms of: calcium phosphate, tri-calcium phosphate, hydroxyapatite, coral hydroxyapatite, demineralized bone matrix, and mineralized bone matrix. Further, the bioabsorbable material can be an injectable solid form of a biopolymer, for example, polylactic acid, polyglycolic acid, polygalactic acid, polycaprolactone, polyethylene oxide, polypropylene oxide, polysulfone, polyethylene, polypropylene, hyaluronic acid or bioglass.  
         [0022]     Though preferably the material is bioabsorbable, it is also possible that the material be merely bioimplantable, e.g., hydroxyapatite or PMMA. Material selection is based on the application. Hence, other abrasives may include calcium carbonate, perlite (an expanded silica abrasive), a colloid-forming clay, quartz, pumice, feldspar, tripoli and calcium phosphate, dextranomor microbeads, silicates of aluminum, calcium, lithium magnesium, lithium magnesium sodium, magnesium aluminum, magnesium, sodium and zirconium, attapulgite, bentonite, fuller&#39;s earth, hectorite, kaolin, montmorillonite, pyrophyllite, and zeolite. Other suitable particulate abrasives include biocompatible (resorbable and non-resorbable) ceramic and polymer particles such as hydroxyapatite, tetra-tri-calcium phosphate, tri-calcium phosphate, calcium sulfate, calcium aluminate and polymethylmethacrylate.  
         [0023]     In some embodiments, particle size of the abrasive may be important. For example, in some applications, a fine particle size that forms a viscous suspension with a particular lavash fluid may be desirable, in other instances, the fluid may be too viscous for effective delivery to a lesion site. In some applications, where heavy abrasive may be desirable, in other instances, the particle size may be too large to pass through the orifice of a delivery device. The abrasive useable in the invention is of a particulate size as to be capable of passing through small gauge needles such as arthroscopic size syringes like the injection syringe of a device of the invention. The particulate abrasive in water preferably is of an average particle size between 0.1 microns and 1500; desirably between 10 microns and 1000 microns and preferably between 50 microns and 400 microns.  
         [0024]     In an embodiment, the debridement fluid includes a proteolytic enzyme (protease) or chemonucleolytic component to further disrupt the matrix of lesion tissue. Suitable enzymes include vibriolysin, krill protease, chymotrypsin, trypsin, collagenase, elastase, dipase, proteinase K, Clostridium multifunctional protease, chymopapain, trypsin, chondroitinase, collagenase, Bacillus subtillis protease or a chemical, such as ethylenediaminetetraacetic acid (EDTA). These proteases are typically employed in therapeutic methods, demonstrate low incidence of undesirable side effects and are commercially available in pure, purified or genetically engineered forms. Other suitable proteases include papain, bromelain, plasminogen activator, plasmin, mast cell protease, lysosomal hydrolase, streptokinase, pepsin, and any or all fungal, bacterial, plant or animal proteases. In this embodiment, the debridement fluid may contain a single protease or a plurality of proteases. These additives are helpful when addressing biofilm or tissue remnants that are in difficult to access areas or areas in which a biofilm or remnant tissue is tightly adhered to the osteolytic lesion or to orthopeadic implant  
         [0025]     An embodiment of the invention comprises following progress of the lesion debridement by fluoroscopy. In this embodiment, contrast agent is injected into the lesion area through a catheter, or preferably through the inner expression cannula of the device of the invention along with debridement fluid. In an example, the debridement instrument is inserted directly into the lesion site. The contrast agent migrates so that the lesion can be radiographically imaged with a fluoroscope. The fluoroscope produces a planar (or two dimensional) image of the lesion area that can be evaluated to monitor the debridement method.  
         [0026]     Features of the invention will become apparent from the drawings and following detailed discussion, which by way of example without limitation describe preferred embodiments of the invention.  
         [0027]      FIG. 1  shows an invention embodiment comprising a debridement device  10  for the washing and debridement of wounds and lesions of a patient. The system  10  includes housing  12  with conduit  14  for the delivery of fluid under pressure. With reference to  FIGS. 1 and 2 , inner expression cannula  18  and outer aspirator circumferential cannula  20  are shown longitudinally form the conduit  14 . The conduit  14  includes a flexible pickup section  22  and a rigid delivery section  24 . The system  10  includes a pressurized lavash fluid reservoir  40  and a fluid transfer pump  50 , which is in fluid communication with inner expression cannula  18  and outer aspirator cannula line  20 .  
         [0028]     The conduit  14  has a pickup end  16  at lavash fluid reservoir  40  to operatively connect the inner cannula  18  from the reservoir  40  (through fluid transfer pump  50 ) to fluid aspirator/expression end  26  of rigid section  24 . The outer aspirator cannula  20  is operatively connected from the fluid transfer pump  50  to fluid delivery/aspirator end  23  to fluid aspirator/discharge end  26  of rigid section  24 . In this example, the fluid within the reservoir  40  is a saline solution. The saline solution comprises 10 weight percent suspended calcium sulfate particulate having a particle size of about 150 microns.  
         [0029]     Fluid transfer pump  50  includes a drivable motor  52  having an elongated rotor shaft  54 . A fluid pressure generating pump  58  is arranged at a first end  56  of the rotor shaft  54 . The pump  58  provides fluid pressure to the dual cannula flexible tube  22  from reservoir  40 . A second end  60  of rotatable shaft  54  is attached to a suction pump  62 , also located within the housing  12 . Suction pump is in fluid communication with a screened disposable collection bottle  34  to provide a vacuum incentive for drainage of fluids to the bag  34 . In this embodiment, a common empowered motor  52  with an extended shaft  54  provides drive for both pressure pump  58  and vacuum source  62 . The arrangement provides for a dual continuous pulsed feed of fluid to a patient lesion area shown in FIGS.  5  for a continuous withdrawal of fluid from the area after treatment of a wound or lesion.  
         [0030]      FIG. 2  is a cut away depiction of rigid delivery section  24  of the conduit  14  including inner cannula  18  and outer cannula  20 . While the section  24  is described as “rigid” it can be a flexible articulating section as well. The section  24  can be of any material that resists degradation from the expressing particles. Inner cannula  18  provides a passageway for lavash fluid from fluid reservoir  40 . The fluid is expressed from syringe end  70  of the inner cannula  18  to a wound or lesion area. An outer wall  30  of conduit  14  forms outer cannula  20  with wall  26  of inner cannula  18  to provide a fluid passageway for aspirating fluid from wound or lesion area after lavage treatment. While this description identifies inner cannula  18  as a passageway to deliver the fluid and outer cannula  20  as a passageway to aspirate, the invention covers other configurations of the conduit  14 . For example, outer cannula  20  can be configured to deliver fluid, while inner cannula  18  aspirates.  
         [0031]     In an embodiment shown in  FIG. 3 , pulsating pump  84  has a rotating wheel  88  arranged to spin within sinusoidal inner surface  90 . The sinusoidal operation of the wheel  88  intermittently squeezes and releases flexible fluid feedline  92 . Feedline  92  includes pickup end  16  at fluid source  40  (shown in  FIG. 1 ). A fluid feed section  96  extends to form inner expression cannula  18 , shown in  FIG. 1 . Rotation of wheel  88  within the sinusoidal surface  90  generates intermittent pulses that are discharged through the pressured inner expression cannula  18  to be expressed at syringe end  70 . In an embodiment, the suction side of the fluid transfer pump  50  is effected in a pulsed manner similar to the fluid pressure side. The suction or vacuum side  62  of the pump  50  can be in-phase or out-of-phase with the fluid pressure pulsating pump  58 .  
         [0032]      FIG. 5  shows a hip joint in need of treatment for a lesion  136  and placement of aspirator/expression end  26  of the debridement device  10  to effect irrigation of the lesion  136 . Further,  FIG. 4  illustrates fluoroscopic monitoring of the debridement.  
         [0033]     First, referring to  FIG. 4 , a user  112  is shown using a system or kit (delineated by dashed outline  110 ) including a support member  114  supporting a monitoring fluoroscope  116 , an image display  118  such as a flat panel television monitor and a lesion debridement device  10 . The user  112  grasps the rigid delivery section  24  of the debridement device  10  and inserts it into a hip joint  124 , shown interiorly in  FIG. 5 , of a patient (the patient&#39;s outline beneath a sheet is indicated at  126 ).  FIG. 5  shows a hip implant  128  that has been surgically implanted into the proximal femur (hip)  130 . The implant  128  may be of any form; for example, fixed, modular, primary, revision, ceramic head or metal head. In non-diseased portions of hip  130 , implant  128  is well-fixed between cortical bone  132  and cancellous bone  134 . In a diseased portion of hip  130 , osteolytic lesion  136  takes up space that would normally be filled with cancellous bone  134 . Lesion  136  is often soft and spongy. Though lesion  136  is depicted in this embodiment as being in the area of the proximal stem, it could be in the area of the distal stem or in another area.  
         [0034]     Usually lesion  136  is surrounded by cancellous bone  134 , and usually also cortical bone  132 . And, typical treatment to debride the lesion  136  is significant and invasive, sometimes involving removal of the implant  128 , open debridement of the lesion area  136  (which enlarges the intramedullary area even further), and implantation of a revision implant. In another typical treatment, location of the lesion  136  is identified by fluoroscope or other imaging process, first and second holes are bored to access the lesion area and lavage fluid is expressed through one hole and is suctioned out the second hold. This procedure operates blindly without assurance that fluid expressed through the first hole delivers lavage to the lesion area. Additionally, the lesion can be tough and resistant to a typical fluid that would be used in the first and second hole procedure.  
         [0035]     The present invention provides a minimally-invasive and accurate approach to treating lesions without removal of implants and revision and without two hole bodily invasion. The invention accurately delivers lavage to assure complete debridement of the lesion. In the present invention, a lavage fluid is utilized that comprises abrasive particles that completely debride even an osteolytic lesion that may be filled with resistant gelatinous masses of nacrotic and fibrous tissue. Additionally, in an embodiment of the invention, insertion of the rigid delivery section  24  of the debridement device into the hip joint, the orientation of the syringe expressing end  70  of the delivery section  24 ; impingement of expressed debridement fluid the lesion and aspirating of fluid containing the nacrotic and fibrous tissue and spent fluid and particles can be monitored to assure complete debridement.  
         [0036]     The lesion debridement is monitored in  FIG. 4  by viewing a fluoroscopic image of the hip joint  124 , lesion area  136 , and inserted rigid delivery section  14 . The patient  126  resides on table  120 , which is essentially transparent to x-rays. A support member  122  supports a fluoroscope and a television monitor  118 . The fluoroscope  116  can be supported by a C-shaped arm  142  device, as shown. Table  120  and patient  126  are positioned within the C formed by arm  142 . Fluoroscope  116  is an x-ray tube unit at a lower end of the C-shaped arm. The x-ray tube unit  116  emits an x-ray beam in a generally upward vertical direction through a diaphragm  146 . The x-ray beam is directed upward through the table  120  and the hip joint  124  of patient  126 . The x-ray beam is received by image intensifier  148 , which includes a television camera (not shown). A fluoroscopic field of view received by the camera at image intensifier  148  is projected on television monitor  118 .  
         [0037]     In operation, patient  126  is aligned between tube unit  116  and image intensifier  148  so that the internal patient&#39;s hip joint  124  is visible on television monitor  116 . User  112  performs a puncture of the patient&#39;s hip area toward the joint  124  with the elongated rigid delivery section  24  of debridement device  10 . The user  112  positions the puncture so that the inserted delivery section  24  syringe end is generally perpendicular to a central axis of an x-ray beam, which is directed upward from fluoroscope x-ray tube unit  116  to image intensifier  148 . The fluoroscopic field of view of fluoroscope  116  is then narrowed to display an image on monitor  116  to permit positioning aspirator/expression end  26  of delivery section  24  within the cancellous bone  134  of hip joint  124  at a location of the osteolytic lesion  136 .  
         [0038]     The user  112  manipulates the aspirator/expression end  26  of delivery section  24 , while remaining outside of the path of the x-ray beam between x-ray tube unit  116  and image intensifier  148  as shown in  FIG. 4 . The user  112  views the location and orientation of aspirator/expression end  26  of delivery section  24  on television monitor  116  while activating the pulse lavage action of the debridement device  20 . Throughout the procedure, the user  112  monitors the location and orientation of the aspirator/expression end  26  to express the particulate abrasive-containing lavage fluid from reservoir  40 . In an embodiment, the user  112  delivers the debridement fluid and aspirates the fluid by alternating pulse lavage. This procedure effectively debrides the lesion  136  and intermittently aspirates resistant osteolytic lesion constituents including nacrotic and fibrous tissue and spent particulate abrasive-containing lavage fluid.  
         [0039]     While preferred embodiments of the invention have been described, the present invention is capable of variation and modification and therefore should not be limited to the precise details of the above examples. For example, the cannulas of the drawings are shown concentric. However, they can be side by side or of any suitable configuration. Also, the invention can relate to a kit that is packaged to include the above-described components for sale, shipment. The invention includes changes and alterations that fall within the purview of the following claims.