Patent Publication Number: US-2022226558-A1

Title: Bone Material Harvesting Device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of the filing date of U.S. Provisional Patent Application No. 62/804,987 filed Feb. 13, 2019, the disclosure of which is hereby incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to devices and methods for harvesting and processing bone and/or cellular material for use in various medical treatments. 
     Pseudarthrosis, also referred to as non-union of bone, is a common complication of fracture treatment. Non-union occurs when a particular patient&#39;s fracture site fails to heal within a specified period of time, and thus requires an intervention (e.g., surgical) in order to achieve proper union and mobility. In some cases, non-unions may be treated by bone grafting (e.g., allograft, autograft, or xenograft), through internal or external fixation, or a combination thereof. Bone grafting offers an opportunity to stimulate the fracture site so that bony formation occurs at the site to properly unionize the fracture. 
     Stem cells (e.g., Mesenchymal stem cells (MSCs), hematopoietic stem cells (HSCs), or other stem cells) are known to be useful with certain graft materials, or by themselves, to facilitate bone growth and formation when used appropriately. For example, adult MSCs are capable of differentiating into a variety of different cell types including osteoblasts (bone cells), chondrocytes (cartilage cells), and adipocytes (fat cells). As such, when incorporated with certain allograft material, stem cells can assist with the proper formation of bone and union of bone parts at a fracture site. Stem cells of the type discussed above must first be extracted from a patient and processed before use. As an example, extracted bone marrow of a patient can provide the necessary stem cells. 
     Bone marrow is typically extracted in a multi-staged procedure. In a first stage of the procedure, bone marrow is aspirated from a patient and then sent to a laboratory for processing. It is only then, in a second stage of the procedure, that the previously harvested bone marrow is processed for the patient&#39;s particular application. Bone marrow from the iliac crest is widely considered the “gold standard” for its superior biologic quality. The drawback of harvesting bone marrow from the iliac crest, however, is that the iliac crest naturally produces a limited quantity of marrow. For surgical interventions requiring a higher volume of bone marrow, such as trauma and orthopedic applications, bone marrow is often harvested from the medullary canal of a long bone (e.g., the femur or tibia), which naturally produces a higher volume of bone marrow than the iliac crest. Bone marrow harvested from the medullary canal has proven to be an effective alternative to bone marrow harvested from the iliac crest and is capable of providing significant regenerative potential. 
     In order to harvest the desired volume of marrow from the medullary canal, a surgeon must access and aspirate bone marrow located deep within the bone canal. This procedure is often performed using a harvesting system that is typically equipped with a reamer, an irrigation system, a suction source (OR suction) and a filter. Although these systems are generally sufficient in harvesting the desired bone material, they are aggressive and carry significant clinical risks such as severe blood loss that often necessitates blood transfusion treatments. In fact, while the medical community appreciates the regenerative potential of bone marrow harvested from the medullary canal of long bone, some medical professionals have begun to question whether harvesting the autograft materials is worth the significant clinical risks. 
     Known harvesting devices are also susceptible to clogging, which results in decreased aspiration function, especially while positioned deep within the medullary canal. Moreover, the harvested material is often diluted and/or contaminated by the water or other solution introduced by the irrigation system. Such dilution or contamination complicates the processing stage of the procedure and necessitates additional filtering or refining of the harvest. Therefore, new and improved bone harvesting devices and methods that address these shortcomings are desired. 
     BRIEF SUMMARY OF THE INVENTION 
     In accordance with a first aspect of the present invention, a device for harvesting bone and/or cellular material (e.g., cancellous bone, bone chips, bone marrow, and stem cells) for use in various medical applications is provided. Among other advantages, the device includes a dual tubed aspiration assembly that reduces clogging and improves aspiration efficiency. In part, due to the improved aspiration efficiency, the device is capable of performing clog-free transportation of even highly viscous material without the irrigation of fluids. As a result, the need for subsequent filtering and excessive processing is eliminated. Furthermore, the improved aspiration function reduces the surgeon&#39;s impulse to aggressively drill into the bone and, in turn, reduces the likelihood of severe blood loss and the clinical complications associated with sever blood loss. 
     One embodiment of the bone harvesting device includes a main body having an internal cavity and a suction port adapted to be coupled to a suction source, an outer tube having an inner surface, an outer surface, a proximal end and a distal end, the proximal end of the outer tube being coupleable to the main body, an inner tube having an inner surface, an outer surface, a proximal end and a distal end, the inner tube being coupleable to the main body and at least partially disposed within the outer tube such that the inner tube is in fluid communication with the internal cavity, and a storage container coupleable to the main body such that the storage container is in fluid communication with the internal cavity for receiving bone and/or cellular material extracted from the patient. 
     In some embodiments, the storage container includes an outer sidewall extending from a base end to a top end, and an inner sidewall at least partially disposed within the outer sidewall and being concave with respect to the top end, the inner sidewall defining a collection space for receiving the extracted bone and/or cellular material. At least a portion of the inner sidewall is spaced a distance from the outer sidewall. 
     In another embodiment, the bone harvesting device may include a body having an internal cavity and a suction port adapted to be coupled to a suction source, an outer tube having an inner surface, an outer surface, a proximal end and a distal end, the proximal end of the outer tube being coupleable to the body, and an inner tube having an inner surface, an outer surface, a proximal end and a distal end. The inner tube may be in fluid communication with the internal cavity and at least partially disposed within the outer tube such that a venting channel is defined between at least a portion of the inner tube and at least a portion of the outer tube. 
     A method of collecting bone and/or cellular material during a bone harvesting procedure is also provided herein. The method includes the steps of (a) operating a reaming, milling, or drilling tool so that the tool reams, mills, or drills into a canal of a bone to generate bone and/or cellular material, (b) inserting a bone harvesting tool into the bone canal, the bone harvesting tool comprising an inner tube at least partially disposed within an outer tube such that a ventilation channel is formed between the inner and outer tubes, (c) generating negative pressure within an internal cavity of a bone harvesting tool, the negative pressure causing the bone and/or cellular material to flow from the patient through the inner tube and into the internal cavity of the bone harvesting tool, and collecting the bone and/or cellular material in a storage container fluidly connected to the internal cavity of the bone harvesting tool. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a bone harvesting device according to an embodiment of the invention. 
         FIG. 2  is an exploded view of the bone harvesting device of  FIG. 1 . 
         FIG. 3  is a partial cross-section of the bone harvesting device of  FIG. 1  taken along line A-A. 
         FIG. 4A  is a side view of an aspiration assembly of the bone harvesting device of  FIG. 1 . 
         FIG. 4B  is an enlarged, partial cross-section view of the proximal end of the aspiration assembly of  FIG. 4A  taken along line B-B. 
         FIG. 4C  is an enlarged, partial cross-section view of the distal end of the aspiration assembly of  FIG. 4  taken along line B-B. 
         FIG. 4D  is a partial, front-oriented perspective view of the aspiration assembly of  FIG. 4A . 
         FIGS. 5A-5F  are front plan views illustrating exemplary arrangements of the aspiration assembly. 
         FIG. 6  is a perspective view of the collection storage container of  FIG. 1 . 
         FIG. 7  is a cross-section view of the collection storage container of  FIG. 6  taken along line C-C. 
         FIG. 8  is flow chart illustrating a method of harvesting bone and/or cellular material from a patient according to an embodiment of the invention. 
         FIG. 9  is a schematic representation illustrating the bone harvesting device of  FIG. 1  aspirating bone and/or cellular material from a patient&#39;s femur. 
         FIG. 10  is a schematic representation illustrating a known bone harvesting device aspirating bone and/or cellular material from a patient&#39;s femur. 
     
    
    
     DETAILED DESCRIPTION 
     As used herein, “axial” means along or parallel to the longitudinal axis of the bone harvesting device and “radial” means in the perpendicular direction thereto. “Interior” or “inner” means radially inward, either toward or facing the longitudinal axis, and “exterior” or “outer” means radially outward, or away from the longitudinal axis. The terms “proximal” and “distal” refer, respectively, to the end of the device nearest the surgeon or other user operating the device, and the opposite end of the device furthest from the user operating the device. 
     Bone harvesting device  10 , as shown in  FIGS. 1 and 2 , includes a body  100 , an aspiration assembly  200  for aspirating bone and/or cellular material from a patient, and a collection storage container  300  for collecting the aspirated material. The phrase bone and/or cellular material refers to material that is extractable from bone, which may optionally then be processed and/or separated to produce another material. For instance, bone and/or cellular material may include cancellous bone, cortical bone (in the form of chips or morselized bone), bone marrow, or stem cells produced from any of the foregoing materials. Such materials are frequently found, for example, in the iliac crest, or the medullary canal of a long bone, as well as the bone surrounding the medullary canal. Bone harvesting device  10  may be formed entirely, or in part, from a transparent medical grade glass or plastic, thereby permitting an operator using the device to observe the collection of bone and/or cellular material during a harvesting procedure. 
     Main body  100  includes a first connector, for example, a threaded bore  102 , for removably securing aspiration assembly  200  to the body, and a second connector, for example, a threaded, lid-shaped platform  104  for removably securing storage container  300  to the body. It will be appreciated, however, that the first and second connectors need not include threads. Instead, aspiration assembly  200  and storage container  300  may alternatively be coupled to the main body  100  via an interference or snap-fit connection, or any other connector known in the art. Main body  100  also defines a suction port  106 , for example, in lid-shaped platform  104  that is configured to be coupled to a suction source S such as a standard operating room suction source (OR suction). Suction port  106  may include a filter to prevent bone and/or cellular material from being drawn from storage container  300  into a suction tube connected suction source S. 
     With specific reference to  FIG. 2 , platform  104  has an aperture  108  that allows harvested bone and/or cellular material to flow from aspiration assembly  200  and into storage container  300  during a harvesting procedure. As shown, main body  100  may also include an ergonomically shaped handle  110  to aid a surgeon in positioning the bone harvesting device during operation. 
     Referring to  FIG. 3 , main body  100  defines an internal cavity  112  that is in fluid communication with aspiration assembly  200  and suction source S. Thus, when OR suction is applied, a negative pressure is produced within internal cavity  110 . This negative pressure draws bone and/or cellular material through aspiration assembly  200 , into the internal cavity, through the aperture  108  and into storage container  300 . 
     Aspiration assembly  200 , as shown in  FIGS. 4A-4D , includes a generally hollow adapter housing  202 , an outer tube  204  and an inner tube  206 . Outer tube  204  and inner tube  206  are formed of a resilient and flexible material that allows the tubes to bend, with respect to the main body  100  and with respect to one another, as the aspiration assembly navigates through the medullary canal of a long bone. Aspiration assembly  200  defines a length between a proximal end  208  and a distal end  210  of the assembly. Bone harvesting device  10  may include a single aspiration assembly  200  measuring approximately 500 mm in length, or a plurality of interchangeable aspiration assemblies having various lengths for harvesting bone of different length. 
     The proximal end  208  of aspiration assembly  200  includes threads  212  for threading adapter  202  within the bore  102  of main body  100 . Adapter  202  need not include threads, however, as aspiration assembly  200  may instead be removably coupled to main body  100  by an interference or snap fit connection, or any other connector known in the art. Adaptor  202  may also include a flange  214 , or similar protrusion having an ergonomic grip to aid a user in coupling and/or decoupling the aspiration assembly  200  to the main body  100 . 
     With specific reference to  FIG. 4B , adaptor  202  has one or more annular grooves  216  within its exterior surface. A gasket  218 , such as an  0 -ring, is provided within each groove  216  to seal the space between the adaptor  202  and the bore  102  of the main body at each location. Adapter  202  also includes first and second inwardly projecting ledges  220 ,  222 . The first ledge  220  is provided adjacent the proximal end of adapter  202 , while the second ledge  222  is positioned between the first ledge and the flange  214 . First ledge  220  protrudes further into the interior space of the adapter  202  than the second ledge  222 . 
     Outer tube  204  extends along a longitudinal axis L from a proximal end  224  to a distal end  226  and includes an exterior surface  228  and an interior surface  230 . The exterior surface  228  of outer tube  204  engages the interior surface of adapter  202 , while the proximal end  224  of the outer tube is bonded, welded, glued or otherwise sealed to a distal facing surface of the second ledge  222 . The distal end  226  of outer tube  204  is preferably rounded, as shown in  FIG. 4C , to reduce trauma as aspiration assembly  200  is operated within the medullary canal of bone. 
     Inner tube  206 , which is positioned at least partially within outer tube  204 , extends along a longitudinal axis L′ from a proximal end  232  to a distal end  234  and includes an exterior surface  236  and an interior surface  238 . Inner tube  206  is bonded, welded, glued or otherwise sealed to an inwardly facing surface of the first ledge  220 , thereby forming a venting channel  240  between the inner and outer tubes. 
     Adapter  202  further defines a vent  242  axially located between the first and second ledges  220 ,  222 . Vent  242  is in fluid communication with ambient air and venting channel  240 . As shown in  FIGS. 4C and 4D , this allows ambient air drawn into vent  242  to flow through venting channel  240  and into the medullary canal adjacent the distal end of the aspiration assembly, while bone and/or cellular material is concurrently aspirated through the inner tube  206  in the opposite direction (e.g., from the distal end of the aspiration assembly toward the main body). The ventilated air provides airflow through the medullary canal during the harvesting process and prevents the medullary canal from becoming negatively pressurized during aspiration and, as a result, reduces the amount of blood loss that occurs during bone and/or cellular aspiration as is further explained hereinafter. 
     In some embodiments, the distal end  234  of inner tube  206  may be proximal to the distal end  226  of outer tube  204 . The vented air is thus drawn around the distal end  234  of inner tube  206  and into the aspiration channel of the inner tube. This reduces clogging at the distal end of the aspiration assembly and maintains optimal suction or aspiration power. Moreover, because inner tube  206  is surrounded by the outer tube  204 , the inner is protected from being damaged. 
     Referring to  FIGS. 5A-5F , various exemplary configurations of the aspiration assembly are described.  FIG. 5A  illustrates a preferred aspiration assembly  200 A, in which inner tube  206   a  is coaxially positioned within outer tube  204   a.  Venting channel  240   a  is thus formed around the entire exterior surface of inner tube  206   a.    
       FIG. 5B  shows aspiration assembly  200   b,  in which the longitudinal axis L′ B  of inner tube  206   b  is offset with respect to the longitudinal axis L B  of outer tube  204   b,  and the exterior surface  236   b  of the inner tube is spaced from the interior surface  230   b  of the outer tube. Venting channel  240   b  entirely surrounds inner tube  206   b.    
       FIG. 5C  illustrates a third configuration, aspiration assembly  200   c,  in which the longitudinal axis L′ C  of inner tube  206   c  is offset with respect to the longitudinal axis L C  of outer tube  204   c.  In this configuration, however, a portion of the exterior surface  236   c  of inner tube  206   c  engages a portion of the interior surface  230   c  of outer tube  204   c.  Venting channel  240   c  is thus only formed around a portion of inner tube  206   c  (i.e., the portion of the exterior surface of the inner tube that is not engaged with the outer tube). 
       FIG. 5D  illustrates aspiration assembly  200   d,  which is similar to aspiration assembly  200   c,  in that the longitudinal axis L′ D  of inner tube  206   d  is offset with respect to the longitudinal axis L D  of outer tube  204   d,  and in that a portion of the exterior surface  236   d  of the inner tube is engaged with a portion of the interior surface  230   d  of the outer tube such that venting channel  240   d  is formed only around a portion of the inner tube. In this configuration, however, the cross-section of outer tube  204   d  is elliptical. It will be appreciated that the inner tube or the outer tube, or both the inner tube and the outer tube, of any of the configurations shown in  FIGS. 5A-5F , may have a cross-section forming an ellipse, a rectangle, a hexagon or any other shape. 
     Aspiration assembly  200   e,  as shown in  FIG. 5E , includes first and second inner tubes  206   e   1 ,  206   e   2 . The longitudinal axis L′ E1  of first inner tube  206   e   1  and the longitudinal axis L′ E2  of second inner tube  206   e   2  are offset with respect to the longitudinal axis L E  of outer tube  204   e.  A portion of the exterior surface  236   e   1  of first inner tube  206   e   1  and a portion of the exterior surface  236   e   2  of second inner tube  206   e   2  are engaged with portions of the interior surface  230   e  of outer tube  204   e.  Venting channel  240   e  is thus formed only around the portions of inner tubes  206   e   1 ,  206   e   2  that are not engaged with outer tube  204   e.  It will be understood, however, that one or both of inner tubes  206   e   1 ,  206   e   2  may instead be spaced from the interior surface  230   e  of outer tube  204   e  such that venting channel  240   e  is formed entirely around the inner tube, or the inner tubes, spaced from the interior surface of the outer tube. 
       FIG. 5F  illustrates aspiration assembly  200   f.  In this configuration, first inner tube  206   f   1  is coaxially positioned within outer tube  204   f  and second inner tube  206   f   2  is coaxially positioned within the first inner tube. Venting channel  240   f  is thus positioned between the first and second inner tubes  206   f   1 ,  206   f   2 . 
     It will be appreciated that aspiration assembly  200  may be constructed as described in any one of the embodiments shown in  FIGS. 5A-5F  or as a combination of the same. Regardless of the specific construction, it is generally desirable that the aspiration channel (e.g., the opening of the inner tube(s)) has a cross-sectional area of at least 12 mm 2 . Moreover, to ensure that sufficient air is vented into the medullary canal, it is desirable that the ratio of the surface area of the cross-section of the venting channel relative to the surface area of the cross-section of the aspiration channel be between 0.15 and 1.0. It will be understood that  FIGS. 5A-5F  illustrate the inner and outer tubes in their unbent, or not flexed, condition. Any bending or flexing of inner tube  206 , relative to outer tube  204 , will change the location of the aspiration channel and, in turn, venting channel  240  relative to the outer tube, but will not modify the cross-sectional area of the aspiration channel or the cross sectional area of the venting channel. 
     Turning now to  FIGS. 6 and 7 , storage container  300  includes a stand  302  and a collection bowl  304 . Storage container  300  is preferably formed as an integral component of a plastic material, for example, through an injection molding process. Alternatively, stand  302  and collection bowl  304  may be coupled together after the components are separately manufactured. 
     Stand  302  may include a cylindrical sidewall  306  that extends from an annular base  308  to a top end  310  and that defines a diameter and height. Base  308  is planar and, thus, configured to rest on a flat surface, for example, an operating table. In a preferred embodiment, the diameter of stand  302  is at least 1.5 times greater than the height to save stance on soft and irregular surfaces. Base  308  may include a flange  312  for added stability. 
     Top end  310  preferably includes an inwardly extending lip  314  for receiving a gasket (not shown) to seal the connection between container  300  and main body  100 . Sidewall  306  may include a plurality of ergonomically shaped grips  316  to aid a user in connecting the storage container  300  to the main body  100  and for removing the container from the body. Grips  316  are also thickened areas of material that strengthen sidewall  306 . 
     Collection bowl  304  includes a sidewall  318  that is connected to lip  314  such that a first portion  320  of the collection bowl sits within the sidewall  306  of stand  302  and a second portion  322  of the collection bowl extends above the top end  310  of the stand. 
     As shown, the second portion  322  includes threads  324 , for example, steep or bayonet threads for coupling the storage container  300  to the lid-shaped platform  104  of the main body. Collections bowl  304  may alternatively include any connector capable of removably coupling the storage container and the main body. 
     The inner surface of sidewall  318  is preferably smooth and hemispherical in shape. In contrast to an ordinary container having a flat base and a sidewall, the interior surface of hemispherical collection bowl  304  is devoid of edges. Because bone and/or cellular material is harvested in relatively small and finite quantities, and through an invasive surgical procedure, it is desirable to preserve all of the material that is harvested from the patient for subsequently processing. The hemispherical shape of the collection bowl  304  assists in this effort as it allows a user to easily remove all of the highly viscous bone and/or cellular material without requiring that the user attempt to scrape material from the edges or the corners of the container before inevitably leaving traces of the material behind. Thus, the hemispherical collection bowl  304  saves the user both time and hassle and maximizes the bone and/or cellular material that is eventually processed. To aid the user in removing bone and/or cellular material from collection bowl  304 , the open end of sidewall  318  is preferably at least 80 mm in diameter, thereby allowing the user to easily fit his or her hand into the collection bowl and to scoop out the material, for example, using his or her fingers. 
     In some embodiments, an indicator scale  326  may be molded to, or imprinted on, storage container  300  such that the user can easily determine the volume of bone and/or cellular material that is present within collection bowl  304 . 
     Bone harvesting device  10  may be used to harvest bone and/or cellular material in a harvesting method as provided herein. The method generally includes extracting bone and/or cellular material from a patient and then sending it to a storage, separation and processing facility (e.g., a “biobank”) for use in a later surgical procedure involving that patient, or a different patient. 
     In many instances, a patient is scheduled to undergo a surgical procedure that necessitates resection of bone and/or reaming of a medullary canal of bone, but in which harvesting bone and/or cellular material is not the primary objective of the surgical procedure. For example, intramedullary nailing (IM nail) procedures, hip replacements, and knee revisions, each require a substantial amount of resection and/or reaming of bone, and therefore, generate bone and/or cellular material as a byproduct of the surgery. 
     During an IM nail procedure, for example, a surgeon seeking to remedy a fracture in the tibia typically first makes an incision in the patient&#39;s skin adjacent the knee. A K-wire is then introduced through the patient&#39;s skin and into an entry point on the patient&#39;s tibial plateau. In a reamed technique, the surgeon then uses the K-wire to guide a reamer through the entry point and into the medullary canal of the long bone. With the K-wire extending into the long bone and past the fracture site (e.g., so that the fracture can be properly reduced), one or more reamers are then used to bore through cortical and cancellous bone, as well as bone marrow of the patient. Because harvesting bone and/or cellular material is not the primary objective of the IM nail procedure, and extraction of these materials can often result in sever blood loss and other complication, bone and/or cellular material is generally only extracted from the medullary canal of the tibia to the extent necessary to make room for the IM implant. Any cortical bone, cancellous bone and bone marrow material that is extracted during the reaming procedure is often discarded. Using harvesting device  10 , however, bone and/or cellular materials can be safely extracted from the patient for subsequent processing and reuse without placing the patient at risk. 
     Referring to  FIGS. 8 and 9 , a method of extracting bone and/or cellular material from a patient is described, using an IM nail procedure remedying a patient&#39;s fractured femur as an illustrative example. It will be understood, however, that bone harvesting device  10  significantly reduces surgical complications when used to aspirate bone and/or cellular material within a medullary cavity and, thus, may likewise be used to harvest material from within the medullary canal of the tibia or any other bone from which bone and/or cellular material may be harvested. 
     In reducing a fractured femur, a surgeon may first approach the fracture by making an incision in the patient&#39;s skin adjacent the hip. The surgeon may then resect the greater trochanter, thereby creating an opening to the medullary canal of the femur. Resection of the greater trochanter generates loose cortical and cancellous bone, which may optionally be collected, either by hand or using bone harvesting device  10 . To collect the loose cortical and cancellous bone using harvesting device  10 , a user turns on the OR suction S, which generates a negative pressure in the internal cavity  112  of main body  10 . Using handle  110 , the user may position the distal end  210  of the aspiration assembly adjacent the resected bone, causing the loose cortical and cancellous bone to be drawn through the aspiration channel of inner tube  206 , into the internal cavity, through aperture  108  in lid  104  and into storage container  300 . After the loose cortical and cancellous bone has been collected, the user may turn off the OR suction S. 
     A K-wire may then be introduced through the patient&#39;s skin and into the medullary canal of the femur. The surgeon may then use the K-wire to guide one or more reaming, milling or drilling tools through an entry point and into the medullary canal of the femur. With the K-wire extending within the medullary canal and past the fracture site, the tool is used to bore through cortical and cancellous bone, as well as bone marrow of the patient, generating bone and/or cellular material in the medullary canal. After the surgeon is satisfied that a bore of sufficient size has been created to receive the IM implant, the tool may be removed from the patient. The surgeon may then optionally collect the residual bone and/or cellular material that adhered to the tool(s) during the reaming, milling or drilling of the medullary canal. 
     Before implanting the IM nail, the surgeon may utilize harvesting device  10  to safely collect bone and/or cellular material from the medullary canal of the femur. In doing so, the OR suction S is again activated. With a negative pressure generated in the internal cavity  112  of main body  110 , the surgeon may position the distal end  210  of the aspiration assembly into the medullary canal of the femur such that the main body is positioned outside the patient. 
     Referring to  FIG. 9 , schematically illustrating only inner tube  206  for clarity, ambient air enters vent  242  ( FIG. 4B ) and flows through venting channel  240  ( FIG. 4 c   ) and into the medullary canal. At the same time, the negative pressure generated within the internal cavity  112  of main body  100  draws bone and/or cellular material through the aspiration channel of inner tube  206  and into storage container  300 . Because air is continually vented within the medullary canal adjacent the distal end  210  of aspiration assembly  200 , the medullary canal does not become negatively pressurized during aspiration of the bone and/or cellular material. Moreover, in the embodiment in which the distal end  234  of inner tube  206  is provided proximal to the distal end  226  of outer tube  204 , the vented air is drawn around the distal end of the inner tube and into the aspiration channel thereof. The curling of the air adjacent the distal end  210  of aspiration assembly  200  guides bone and/or cellular material into the aspiration channel of inner tube  206  such that clogging is reduced and optimal suction or aspiration power is maintained. 
     In contrast, as is shown in  FIG. 10 , illustrating a known bone harvesting device that does not include the described venting features, as bone and/or cellular material is aspirated though the aspiration assembly, the medullary canal becomes negatively pressurized. The negative pressure results in the aspiration of blood and can result in sever blood loss. Additionally, as the medullary canal drops in pressure, the aspiration power of the assembly is reduced, resulting in decreased aspiration efficiency and often clogging of the assembly. 
     Referring back to  FIG. 8 , the user may optionally combine the bone and/or cellular materials into a cumulate harvest. In order to do so, the user first uncouples storage container  300  from main body  100 , sticks his or her hand into collection bowl  304  and scoops out all of the bone and/or cellular material. The bone and/or cellular material may then be combined with the residual bone and/or cellular material collected from the reaming, milling or drilling tools and/or the loose bone and/or cellular material generated during the bone resection step. 
     After the bone and/or cellular material has been harvested, the surgeon may implant the IM nail and finish the IM nail procedure. 
     The bone and/or cellular material may then be sent to a biobank as separate collections, or as a cumulate harvest, for subsequent processing and use in a later surgical procedure involving that patient, or a different patient. 
     Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.