Source: http://patents.com/us-6248110.html
Timestamp: 2013-12-10 12:48:40
Document Index: 29682020

Matched Legal Cases: ['arts 212', 'arts 12', 'arts 212', 'arts 212', 'arts 212', 'art 284', 'art 285', 'arts 284']

US Patent # 6,248,110. Systems and methods for treating fractured or diseased bone using
expandable bodies - Patents.com
United States Patent 6,248,110
Inventors: Reiley; Mark A (Piedmont, CA), Scholten; Arie (Fremont, CA), Talmadge; Karen D (Palo Alto, CA), Scribner; Robert M (Los Altos, CA) Assignee:
Related U.S. Patent Documents Application NumberFiling DatePatent NumberIssue Date 659678Jun., 1996 485394Jun., 1995 188224Jan., 1994 Current U.S. Class:
606/93 ; 606/192; 606/92
Current International Class: A61B 17/12 (20060101); A61F 2/46 (20060101); A61M 25/10 (20060101); A61B 10/00 (20060101); A61B 17/72 (20060101); A61B 17/88 (20060101); A61B 17/68 (20060101); A61F 2/44 (20060101); A61F 2/36 (20060101); A61F 2/40 (20060101); A61F 2/42 (20060101); A61B 17/00 (20060101); A61B 17/02 (20060101); A61B 17/74 (20060101); A61B 17/78 (20060101); A61B 19/00 (20060101); A61F 2/28 (20060101); A61B 19/02 (20060101); A61F 2/30 (20060101); A61F 2/00 (20060101); A61F 2/38 (20060101); A61B 017/58 ()
Field of Search: 606/92,93,94,60,61,62,86,91,191,192 623/7,8
Other References Melton, III, L. Joseph et al., "Perspective: How Many Women Have Osteoporosis", Journal of Bone and Mineral Research, vol. 7, No. 9, 1992, pp.
.Harrington, Kevin D., The Use of Methylmethacrylate as a Adjunct in the Internal Fixation of Malignant Neoplastic Fractures, The Journal of Bone and Joint Surgery, vol. 54A, No. 8, Dec. 1972, pp. 1665-1676.
.Instructoins entitled "Exeter Pressurizer System", by Howmedica Inc., Orthopaedics Division, 1979, 2 pages.. Primary Examiner: Recla; Henry J.
No. 08/188,224, filed Jan. 26, 1994 entitled, "Improved Inflatable Device
For Use In Surgical Protocol Relating To Fixation Of Bone", now abandoned.
Claims We claim:1. A method for treating bone comprising the steps of
2. A method according to claim 1 wherein the conveying step includes conveying bone cement for discharge through the nozzle.
4. A method for compacting cancellous bone comprising the steps of
5. A method according to claim 3 further including the step of filling the cavity with a material.
9. A method according to claim 3
wherein the first and second expandable bodies assume expanded geometries sequentially. Description FIELD OF THE INVENTION
When cancellous bone becomes diseased, for example, because of osteoporosis, avascular necrosis, or cancer, the surrounding cortical bone becomes more prone to compression fracture or collapse. This is because the cancellous bone no longer
There are 2 million fractures each year in the United States, of which about 1.3 million are caused by osteoporosis alone. There are also other bone disease involving infected bone, poorly healing bone, or bone fractured by severe trauma. These
U.S. Pat. Nos. 4,969,888 and 5,108,404 disclose apparatus and methods for the fixation of fractures or other conditions of human and other animal bone systems, both osteoporotic and non-osteoporotic. The apparatus and methods employ an
expandable body to compress cancellous bone and provide an interior cavity. The cavity receives a filling material, which hardens and provides renewed interior structural support for cortical bone.
One aspect of the invention provides systems and methods for treating bone using an expandable wall in association with a nozzle for discharging a material. According to this aspect of the invention, the systems and methods insert both the body
and the nozzle into a bone having cortical bone surrounding an interior volume occupied, at least in part, by cancellous bone. The systems and methods causing the body to assume an expanded geometry while occupying the interior volume in the presence of
the nozzle to compact cancellous bone and form a cavity in the interior volume. The systems and methods convey a material for discharge through the nozzle into the cavity at least partially while the body occupies the interior volume.
In a preferred embodiment, the systems and methods convey bone cement for discharge through the nozzle, while the body is in the expanded geometry or a partially expanded geometry. The systems and methods can also cause the expanded geometry of
Another aspect of the invention provides systems and methods for treating bone using first and second expandable bodies. The first expandable body is inserted into the interior bone volume through a first access path in cortical bone. The
second expandable body is inserted into the same interior bone volume through a second access path in cortical bone different than the first access path. The systems and methods cause each of the bodies to assume an expanded geometry for jointly
In one embodiment, the first and second access paths comprise different ipsilateral posterolateral accesses. In another embodiment, the first and second access paths comprise different transpedicular accesses. In yet another embodiment, the
Another aspect of the invention provides a body for insertion into a bone, which comprises two expandable zones. The first zone assumes an elongated expanded geometry. The elongated geometry presents a first dimension, which extends
substantially across the interior volume, to form a barrier within the interior volume. The elongated geometry also presents a second dimension less than the first dimension, which leaves a region of substantially uncompacted cancellous bone extending
from the barrier within the interior volume. The second expandable zone assumes a different expanded geometry, which compacts cancellous bone to form a cavity in the region. The barrier formed by the first zone directs expansion of the second zone in
FIG. 49 is an enlarged view of the expandable body associated with the system shown in FIG. 47 inside a bone for the purpose of harvesting bone marrow. The invention may be embodied in several forms without departing from its spirit or
essential characteristics. The scope of the invention is defined in the appended claims, rather than in the specific description preceding them. All embodiments that fall within the meaning and range of equivalency of the claims are therefore intended
This Specification describes new systems and methods to treat bones using expandable bodies. The use of expandable bodies to treat bones is disclosed in U.S. Pat. No. 4,969,888 and 5,108,404, which are incorporated herein by reference. Improvements in this regard are disclosed in U.S. patent application, Ser. No. 08/188,224, filed Jan. 26, 1994; U.S. patent application Ser. No. 08/485,394, filed Jun. 7, 1995; and U.S. patent application Ser. No. 08/659,678, filed Jun. 5, 1996,
The new systems and methods will be first described with regard to the treatment of vertebra. It should be appreciated, however, the systems and methods so described are not limited in their application to vertebrae. As will be described in
As FIG. 1 shows, the spinal column 10 comprises a number of uniquely shaped bones, called the vertebrae 12, a sacrum 14, and a coccyx 16(also called the tail bone). The number of vertebrae 12 that make up the spinal column 10 depends upon the
species of animal. In a human (which FIG. 1 shows), there are twenty-four vertebrae 12, comprising seven cervical vertebrae 18, twelve thoracic vertebrae 20, and five lumbar vertebrae 22.
As FIGS. 1 to 3 show, each vertebra 12 includes a vertebral body 26, which extends on the anterior (i.e., front or chest) side of the vertebra 12. As FIGS. 1 to 3 show, the vertebral body 26 is in the shape of an oval disk. As FIGS. 2 and 3
show, the vertebral body 26 includes an exterior formed from compact cortical bone 28. The cortical bone 28 encloses an interior volume 30 of reticulated cancellous, or spongy, bone 32 (also called medullary bone or trabecular bone). A "cushion, "
The vertebral arch 40 surrounds the spinal canal 37. The pedicle 42 of the vertebral arch 40 adjoins the vertebral body 26. The spinous process 44 extends from the posterior of the vertebral arch 40, as do the left and right transverse
The insertion of the body 56 into the interior volume 30 of a targeted vertebral body 26 can be accomplished in various ways. FIGS. 5A to 5Q show the insertion of the body 56 using a transpedicular approach, which can be performed either with a
In the described procedure, a patient lies on an operating table, while the physician introduces a conventional spinal needle assembly 60 into soft tissue in the patient's back. The patient can lie facedown on the table, or on either side, or at
an oblique angle, depending upon the physician's preference. Indeed, the procedure can be performed through an open anterior procedure or an endoscopic anterior procedure, in which case the tool 48 may be introduced from the anterior aspect of the
The spinal needle assembly 60 comprises a stylet 62 slidable housed within a stylus 64. The assembly 60 typically has, for example, about an 18 gauge diameter. Other gauge diameters can and will be used to accommodate appropriate guide pins, as
Under radiologic, CT, or MRI monitoring, the physician advances the assembly 60 through soft tissue (designated S in FIG. 5A) down to and into the targeted vertebra 12, as FIG. 5A shows. The physician will typically administer a local
anesthetic, for example, lidocaine, through assembly 60. In some cases, the physician may prefer other forms of anesthesia.
FIG. 5A shows gaining access to cancellous bone 32 through the pedicle 42, which is called transpedicular access. However, posterolateral access, through the side of the vertebral body 12 (designated P-L and shown in phantom lines in FIG. 5A),
After positioning the spinal needle assembly 60 in cancellous bone 32, the physician holds the stylus 64 and withdraws the stylet 62 (see FIG. 5B). Still holding the stylus 64, the physician slides a guide pin 66 through the stylus 64 and into
the cancellous bone 32 (see FIG. 5C). The physician now removes the stylus 64, leaving the guide pin 66 deployed within the cancellous bone 32, as FIG. 5D shows.
As FIG. 5E shows, the physician makes a small incision (designated I in FIG. 5E) in the patients back to accommodate a trocar 68. The physician inserts the trocar 68 through the soft tissue S along the guide pin 66 down to the pedicle 42. The
As FIG. 5F shows, the physician next slides an outer guide sheath 72 over the trocar 68. The distal end 74 of the outer guide sheath 72 is likewise tapped into the pedicle 42. The physician removes the trocar 68, leaving the guide pin 66 and
outer guide sheath 72 in place, as FIG. 5G shows. Alternatively, the trocar 68 and guide sheath 72 can be introduced together in one step.
As FIG. 5H shows, the physician advances a drill bit 76 (for example, 5 mm in diameter) over the guide pin 66 through the outer guide sheath 72. Under X-ray control (or using another external visualizing system), the physician operates the drill
bit 76 to open a passage 78 through the pedicle 42 and into the cancellous bone 32. The drilled passage 78 preferable extends no more than 95% across the vertebral body 26.
As FIG. 5J(1) shows, the physician next advances the catheter tube 50 and expandable body 56 through the outer guide sheath 72 and into the drilled passage 78 in the cancellous bone 32. As best shown in FIG. 5J(2), the body 56 is maintained in a
straightened, collapsed condition distally beyond the end of the catheter tube 50 during transport through the guide sheath 72 and into the drilled passage 78 by a generally rigid, external protective sleeve 73, which surrounds the body 56. Alternatively, an internal stiffening member (not shown) can extend within the body 56, to keep the body 56 in the desired distally straightened condition during passage through the guide sheath 72. Once the body 56 is located in the desired location
within the passage 78, the physician pulls the sleeve 73 back, to uncover the body 56. The expandable body 56 can be dipped into thrombin prior to its introduction into the vertebral body 26 to facilitate in situ coagulation.
The materials for the catheter tube 50 are selected to facilitate advancement of the body 56 into cancellous bone through the guide sheath 72. The catheter tube 50 can be constructed, for example, using standard flexible, medical grade plastic
materials, like vinyl, nylon, polyethylenes, ionomer, polyurethane, and polyethylene tetraphthalate (PET). The catheter tube 50 can also include more rigid materials to impart greater stiffness and thereby aid in its manipulation. More rigid materials
that can be used for this purpose include Kevlar.TM. material, PEBAX.TM. material, stainless steel, nickel-titanium alloys (Nitinol.TM. material), and other metal alloys.
Once the protective sheath 73 is withdrawn, the wall 58 of the body 56 is capable of assuming an expanded geometry within the interior volume 30(generally shown in FIG. 5K(1)). To accommodate expansion of the body 56, the catheter tube 50
includes a first interior lumen 80 (see FIG. 4). The lumen 80 is coupled at the proximal end of the catheter tube 50 to a pressurized source of fluid 82. The fluid 82 is preferably radio-opaque to facilitate visualization. For example, Renograffin.TM. can be used for this purpose.
The lumen 80 conveys the fluid 82 into the body 56 under pressure. As a result, the wall 58 expands, as FIG. 5K(l) shows. Because the fluid 82 is radio-opaque, body expansion can be monitored fluoroscopically or under CT visualization. Using
Expansion of the wall 58 enlarges the body 56 and compacts cancellous bone 32 within the interior volume 30. As FIG. 5K(2) shows, the presence of the sheath 73 serves to keep the proximal end of the body 56 away from edge-contact with the distal
The compaction of cancellous bone 32 forms a cavity 84 in the interior volume 30 of the vertebral body 26. The compaction of cancellous bone also exerts interior force upon cortical bone, making it possible to elevate or push broken and
compressed bone back to or near its original prefracture position. Using a single transpedicular access (as FIG. 5K(1) shows), the cavity 84 occupies about one-half of the interior volume 30. As will be described in greater detail later, using multiple
As FIG. 4 shows, the proximal end of the catheter tube 50 is preferably coupled by tubing to a source of negative air pressure 86. The negative pressure is conveyed through a second interior lumen 81 to one or more suction holes 88 on the distal
end of the catheter tube 50. Prior to and during the expansion of the body 56, suction is applied to remove fats and other debris through the suction holes 88 for disposal. A separate suction-irrigation tool can be deployed through the guide sheath 72
The body 56 is preferably left inflated for an appropriate waiting period, for example, three to five minutes, to allow coagulation inside the vertebral body 26. After the appropriate waiting period, the physician collapses the body 56 and
removes it through the outer guide sheath 72 (see FIG. 5L). To facilitate removal, the exterior surface of the body 56 can be treated, e.g., by ion beam-based surface treatment, to reduce friction during passage through the outer guide sheath 72. As
As FIG. 5M shows, an injector nozzle or tip 90, coupled by an injector tube 92 to an injector gun 94, is inserted through the outer guide sheath 72 into the formed cavity 84. The injector gun 94 carries a filling material 96. The filling
The injector gun 94 can comprise a cement gun made, for example, by Stryker Corporation (Kalamazoo, Mich.) This particular injector gun 94 has a manually operated injection grip 98 with a mechanical advantage of about 9 to 1. Other injection
guns may be used, having more or less mechanical advantage. Non-manually operated injection guns can also be used.
As FIG. 5M shows, the injector gun 94 pushes the filling material 96 into the cavity 84. While injecting the material 96, the physician preferably begins with the injector tip 90 positioned at the anterior region of the cavity 84 (as FIG. 5M
shows). The physician progressively moves the tip 90 toward the posterior region of the cavity 84 (as FIG. 5N shows), away from the flow of the material 96 as it enters and fills the cavity 84. The physician observes the progress of the injection
Upon removing the injector tube 92 from the outer guide sheath 72, the physician may, if necessary, tamp residual filling material 96 from the distal end 74 of the outer guide sheath 72 into the cavity 84. If fluoroscopic examination reveals
FIG. 7 shows an alternative technique for filling the cavity. In this technique, the injector tip 90 occupies the cavity 84 while the expandable body 56 is collapsing within the cavity 84. As the body 56 collapses, the tip 90 injects material
96 into the part of the cavity 84 that the collapsing body 56 no longer occupies. The increasing volume of the cavity 84 not occupied by the collapsing body 56 is thereby progressively filled by an increasing volume of material 96. The presence of the
As FIG. 8C shows, the catheter tube 652 has concentric inner and outer lumens, respectively 658 and 660. The inner lumen 658 communicates, by proximal tubing 664, with an injector gun 94, of the type previously described. The inner lumen 658
also communicates with an injector nozzle or tip 666 at the distal catheter tube end 656. Operation of the gun 94 serves to inject filling material 96 through the nozzle 666 (as FIG. 8A shows).
The outer lumen 660 communicates, via proximal tubing 668, with a source 82 of pressurized liquid. The outer lumen 660 also communicates with ports 670 formed on the distal catheter tube end 656 underlying the expandable body 662. Operation of
As FIG. 8A shows, the physician introduces the tool 650 into the cancellous bone 32. The physician expands the body 662 to create the cavity 84. Once the cavity 84 is formed, the physician begins to collapse the body 662, while injecting the
filling material 96 through the nozzle 666. The volume of the cavity 84 occupied by the collapsing body 662 is progressively filled by the increasing volume of filling material 96 injected through the nozzle 666.
As earlier described, the collapsing body 662 serves to compact and spread the filling material 96 more uniformly within the cavity 84. Under fluoroscopic monitoring, the physician progressively retracts the distal end 656 of the tool 650 from
The above described procedure, carried out in a minimally invasive manner, can also be carried out using an open surgical procedure. Using open surgery, the physician can approach the bone to be treated as if the procedure is percutaneous,
except that there is no skin and other tissues between the surgeon and the bone being treated. This keeps the cortical bone as intact as possible, and can provide more freedom in accessing the interior volume 30 of the vertebral body.
The material of the body wall 58 can be selected according to the therapeutic objectives surrounding its use. For example, materials including vinyl, nylon, polyethylenes, ionomer, polyurethane, and polyethylene tetraphthalate (PET) can be used. The thickness of the body wall 58 is typically in the range of 2/1000ths to 25/1000ths of an inch, or other thicknesses that can withstand pressures of up to, for example, 250-500 psi.
If desired, the material for the wall 58 can be selected to exhibit generally elastic properties, like latex. Alternatively, the material can be selected to exhibit less elastic properties, like silicone. Using expandable bodies 56 with
generally elastic or generally semi-elastic properties, the physician monitors the expansion to assure that over-expansion and wall failure do not occur. Furthermore, expandable bodies 56 with generally elastic or generally semi-elastic properties will
For example, expandable bodies 56 with generally elastic properties will exhibit the tendency to backflow or creep into the outer guide sheath 72 during their expansion. It is therefore necessary to internally or externally restrain a body 56
that is subject to creeping, to keep it confined within the interior bone region. In FIG. 6, an exterior sealing element 100 is provided for this purpose. In FIG. 6, the sealing element 100 takes the form of a movable o-ring.
The physician advances the o-ring 100 along the catheter tube 50 inside the guide sheath 72 using a generally stiff stylet 102 attached to the o-ring 100. The physician locates the o-ring 100 at or near the distal end 54 of the catheter tube 50
prior to conveying the liquid 82 to expand the body 56. The o-ring 100 is held in place by the generally stiff stylet 102, which provides a counter force to prevent backward movement of the o-ring 100 in the guide sheath 72 as the body 56 expands. The
o-ring 100 thereby keeps all or a substantial portion of the generally elastic body 26 confined inside the interior volume 30. The body 56 thereby serves to compact as much of the cancellous bone 32 as possible.
The use of an external sealing element 100 to restrain the expandable body 56 may not be necessary when relatively inelastic materials are selected for the body 56. For example, the material for the body wall 58 can be selected to exhibit more
inelastic properties, to limit expansion of the wall 58 prior to wall failure. The body wall 58 can also include one or more restraining materials, particularly when the body wall 58 is itself made from more elastic materials. The restraints, made from
flexible, inelastic high tensile strength materials, limit expansion of the body wall 58 prior to wall failure. Representative examples of generally inelastic wall structures will be described in greater detail later.
imparted to the body 56, when it is substantially expanded. The shape and size can be predetermined according to the shape and size of the surrounding cortical bone 28 and adjacent internal structures, or by the size and shape of the cavity 84 desired
32 in the interior volume 30. A body 56 having a substantially expanded size and shape in the range of about 40% to about 99% of the cancellous bone volume is preferred.
the cancellous bone volume. In this embodiment, the drilled passage 78 extends directly to the localized site of injury, to enable targeted introduction of the body 26.
human skeletal anatomy, along with their knowledge of the site and its disease or injury. The physician is also able to select the materials and geometry desired for the body 56 based upon prior analysis of the morphology of the targeted bone using, for
example, plain films, spinous process percussion, or MRI or CRT scanning. The materials and geometry of the body 56 are selected to create a cavity 84 of desired size and shape in cancellous bone 32 without applying harmful pressure to the outer
In some instances, it is desirable, when creating the cavity 84, to move or displace the cortical bone 28 to achieve the desired therapeutic result. Such movement is not per se harmful, as that term is used in this Specification, because it is
indicated to achieve the desired therapeutic result. By definition, harm results when expansion of the body 56 results in a worsening of the overall condition of the bone and surrounding anatomic structures, for example, by injury to surrounding tissue
Formation of a desired cavity geometry in cancellous bone 32 using an expandable body 56 can be accomplished in diverse ways to achieve the desired therapeutic effect. The foregoing disclosure envisions the deployment of a single expandable body
FIG. 9 shows the representative deployment of multiple expandable bodies 56A and 56B through a single outer guide sheath 72, which is arranged to provide transpedicular access. It should be understood that deployment of multiple expandable
bodies can likewise be achieved through an outer guide sheath 72 arranged to provide a posterolateral access, through the side of the vertebral body 26 (as shown as P-L in phantom lines in FIG. 9). In FIG. 9, the expandable bodies 56A and 56B are
In the alternative embodiment shown in FIG. 10, a tool 109 comprising an array 108 of catheter tubes 50A and 50B is provided. Each catheter tube 50A and 50B each carries an expandable body 56A and 56B, which are shown in FIG. 10 in a collapsed
condition. In FIG. 10, the distal ends of the catheter tubes 50A and 50B are joined by a connector 106, for simultaneous deployment through an outer guide sheath 72 into the vertebral body 26, as FIG. 9 shows. As before described, a slidable protective
sheath 73 encloses the bodies 56A and 56B during passage through the guide sheath 72. Upon withdrawal of the protective sheath 73, expansion of the bodies 56A and 56B, either simultaneously or sequentially, creates a cavity 84. If desired, the
Alternatively, as shown in FIG. 11, the bodies 56A and 56B possess different geometries when substantially expanded, thereby presenting an asymmetric arrangement for compacting cancellous bone 32. A generally asymmetric cavity 84 results. By
in the cancellous bone 32. The deployment of multiple expandable bodies 56 makes it possible to form cavities 84 having diverse and complex geometries within bones of all types. Multiple expandable bodies having generally the same geometry can be
in phantom lines in FIG. 10), which is manipulated in the same as previously described in connection with FIGS. 5J(1) and 5J(2). There are, of course, other ways to straighten the bodies 56 for deployment into bone, such as through the use of internal
Deployed from dual access sites as shown in FIGS. 12 and 13, the multiple expandable bodies 56A and 56B each forms a cavity 84A and 84B (shown in FIG. 14). The cavities 84A and 84B are transversely spaced within the cancellous bone 32. The
transversely spaced cavities 84A and 84B may adjoin to form a single combined cavity (designated C in FIG. 14), into which the filling material 96 is injected. Alternatively, as FIG. 15 shows, the transversely spaced cavities 84A and 84B may remain
separated by a region of cancellous bone (designated by numeral 110 in FIG. 13). In this arrangement, the filling material 96 is injected into multiple, individual cavities 84A and 84B within the interior volume.
As another example, multiple expandable bodies 56A and 56B can access the vertebral body 26 from the same general region of the vertebra. FIG. 16 shows a representative dual ipsilateral posterolateral access, in which two outer guide sheaths 72A
Deployed from these access sites (see FIG. 17), the multiple expandable bodies 56A and 56B form vertically spaced, or stacked, cavities 84A and 84B. The vertically spaced cavities 84A and 84B may adjoin to form a single combined cavity
(designated C in FIG. 17), into which the filling material 96 is injected. Alternatively (see FIG. 18), the vertically spaced cavities 84A and 84B may be separated by a region of cancellous bone (designated by numeral 110 in FIG. 18), forming multiple
Systems for treating bone using multiple expandable bodies can include directions 79 (see FIG. 12) for deploying the first and second expandable bodies. For example, the directions 79 can instruct the physician to insert a first expandable body
In any of the above-described examples, each guide sheath 72A or 72B can itself accommodate a single expandable body or multiple expandable bodies. The size and shape of the bodies may be the same, or they may vary, according to the desired
FIG. 20 shows a representative embodiment of an expandable body, which is broadly denoted by the numeral 210. The body 210 comprises a pair of hollow, inflatable, non-expandable parts 212 and 214 of flexible material, such as PET or Kevlar. Parts 12 and 14 have a suction tube 216 therebetween for drawing fats and other debris by suction into tube 216 for transfer to a remote disposal location. The catheter tube 216 has one or more suction holes so that suction may be applied to the open
The parts 212 and 214 are connected together by an adhesive which can be of any suitable type. Parts 212 and 214 are doughnut-shaped, as shown in FIG. 20 and have tubes 218 and 220 which communicate with and extend away from the parts 212 and
214, respectively, to a source of inflating liquid under pressure (not shown). The liquid expands the body 210 as already described.
FIG. 21 shows a modified doughnut shape body 280 of the type shown in FIG. 20, except the doughnut shapes of body 280 are not stitched onto one another. In FIG. 21, body 280 has a pear-shaped outer convex surface 282 which is made up of a first
hollow part 284 and a second hollow part 285. A tube 288 is provided for directing liquid into the two parts along branches 290 and 292 to inflate the parts after the parts have been inserted into the interior volume of a bone. A catheter tube 216 may
or may not be inserted into the space 296 between two parts of the balloon 280 to provide irrigation or suction. An adhesive bonds the two parts 284 and 285 together.
FIG. 22 shows another representative embodiment of an expandable body, designated 309. The body 309 has a generally round geometry and three expandable body units 310, 312 and 314. The body units 310, 312, and 314 include string-like external
restraints 317, which limit the expansion of the body units 310, 312, and 314 in a direction transverse to the longitudinal axes of the body units 310, 312, and 314. The restraints 317 are made of the same or similar material as that of the body units
A tubes 315 direct liquid under pressure into the body units 310, 312 and 314 to expand the units and cause compaction of cancellous bone. The restraints 317 limit expansion of the body units prior to failure, keeping the opposed sides 377 and
FIG. 23 shows another representative embodiment of an expandable body 230, which has a kidney-shaped geometry. The body 230 has a pair of opposed kidney-shaped side walls 232 and a continuous end wall 234. A tube 238 directs liquid into the
FIG. 24 shows another representative embodiment of an expandable body 242, which also has a kidney-shaped geometry. The body 242 is initially a single chamber bladder, but the bladder is branded along curved lines or strips 241 to form
attachment lines 244 which take the shape of side-by-side compartments 246 which are kidney shaped as shown in FIG. 25. A similar pattern of strips as in 240 but in straight lines would be applied to a body that is square or rectangular. The branding
The eventual selection of the size and shape of a particular expandable body or bodies to treat a targeted vertebral body 26 is based upon several factors. When multiple expandable bodies are used, the total combined dimensions of all expandable
The anterior-posterior (A-P) dimension (see FIG. 26) for the expandable body or bodies is selected from the CT scan or plain film or x-ray views of the targeted vertebral body 26. The A-P dimension is measured from the internal cortical wall of
the anterior cortex to the internal cortical wall of the posterior cortex of the vertebral body. In general, the appropriate A-P dimension for the expandable body or bodies is less than this anatomic measurement.
The appropriate side to side dimension L (see FIG. 26) for an expandable body or bodies is also selected from the CT scan, or from a plain film or x-ray view of the targeted vertebral body. The side to side distance is measured between the
internal cortical walls laterally across the targeted vertebral body. In general, the appropriate side to side dimension L for the expandable body is less than this anatomic measurement.
The height dimensions H of the expandable body or bodies (see FIG. 26) is chosen by the CT scan or x-ray views of the vertebral bodies above and below the vertebral body to be treated. The height of the vertebral bodies above and below the
vertebral body to be treated are measured and averaged. This average is used to determine the appropriate height dimension of the chosen expandable body.
Side to Posterior Side Height (H) (A-P) Dimension Dimension Dimension (L) of of Typical of Typical Typical Expandable Expandable Expandable Vertebra Body or Body or Body or Type Bodies Bodies Bodies Lumbar 0.5 cm to 0.5 cm to 0.5 cm to 4.0 cm 4.0 cm 5.0 cm Thoracic 0.5 cm to 0.5 cm to 0.5 cm to 3.5 cm 3.5 cm 4.0 cm
A preferred expandable body 56 for use in a vertebral body is stacked with two or more expandable members of unequal height (see FIG. 26), where each member can be separately inflated through independent tube systems. The total height of the
stack when fully inflated should be within the height ranges specified above. Such a design allows the fractured vertebral body to be returned to its original height in steps, which can be easier on the surrounding tissue, and it also allows the same
Like vertebrae, the interior regions of long bones substantially occupied by cancellous bone can be treated with the use of one or more expandable bodies. FIG. 43 shows representative regions of the human skeleton 600, where cancellous bone
regions of long bones can be treated using expandable bodies. The regions include the distal radius (Region 602); the proximal tibial plateau (Region 604); the proximal humerus (Region 606); the proximal femoral head (Region 608); and the calcaneus
anatomic position. This is a particularly important attribute for the successful treatment of compression fractures or cancellous bone fractures in the appendicular skeleton, such as the distal radius, the proximal humerus, the tibial plateau, the
FIGS. 27 and 28 show a representative expandable body 260 for use in the distal radius. The body 260, which is shown deployed in the distal radius 252, has a shape which approximates a pyramid but more closely can be considered the shape of a
humpbacked banana. The geometry of the body 260 substantially fills the interior of the space of the distal radius to compact cancellous bone 254 against the inner surface 256 of cortical bone 258.
The body 260 has a lower, conical portion 259 which extends downwardly into the hollow space of the distal radius 252. This conical portion 259 increases in cross section as a central distal portion 261 is approached. The cross section of the
body 260 is shown at a central location (FIG. 27), which is near the widest location of the body 260. The upper end of the body 260, denoted by the numeral 262, converges to the catheter tube 288 for directing a liquid into the body 260 to expand it and
FIG. 29A shows a representative embodiment of an expandable body 266 for use in the proximal humerus 269. The body 266 is spherical for compacting the cancellous bone 268 in a proximal humerus 269. If surrounding cortical bone has experienced
A mesh 270, embedded or laminated and/or winding, may be used to form a neck 272 on the body 266. A second mesh 270a may be used to conform the bottom of the base 272a to the shape of the inner cortical wall at the start of the shaft. These
The body 266 has a catheter tube 277 into which liquid under pressure is forced into the body to expand it to compact the cancellous bone in the proximal humerus. The body 266 is inserted into and taken out of the proximal humerus in the same
FIG. 29B shows another representative embodiment of an expandable body 266' for use in the proximal humerus 269. Instead of being spherical, the body 266' shown in FIG. 29B has a generally cylindrical geometry for compacting the cancellous bone
268 in a proximal humerus 269. Alternatively, the cylindrical body 266' can be elongated to form an elliptical or football-shaped geometry. Typical dimensions for a cylindrical or elliptical body vary from 0.6 cm to 3.0 cm in diameter to 3.0 cm to 14.0
FIG. 30A shows a representative expandable body 280 for treating a tibial plateau fracture. The body 280 may be introduced into the tibia from any direction, as desired by the physician, for example, from the top, or medial, lateral, anterior,
posterior, or oblique approach. In FIG. 30A, the body 280 has been introduced into cancellous bone 284 from the anterior side of the tibia 283 and is shown position in one side 282 of the tibia 283.
The body 280, when substantially inflated (as FIG. 30A shows), compacts the cancellous bone in the layer 284 surrounding the body 280. If the tibia plateau has experienced depression fracture, expansion of the body 280 also serves to move the
tibia plateau back to or near its anatomic elevation before fracture, as FIG. 30A shows. Fractures on both the medial and lateral sides of the tibia can be treated in this manner.
The restraints 288 can be in the form of strings or flexible members of any suitable construction. The restraints 288 limit expansion of the body 280 prior to failure. The restraints 288 make the sides 285 and 287, when the body 280 is
A tube 290 is coupled to the body 280 to direct liquid into and out of the body to expand it. The body is inserted into and taken out of the tibia in the same manner as that described above with respect to the vertebral bone. FIG. 30C shows a
Other geometries and configurations can also be used. For example, as FIG. 32 shows, two or more expandable bodies 280(1), 280(2), and 280(3) can be stacked one atop another to produce a different cavity geometry and to enhance plateau fracture
displacement. The multiple bodies 280(1), 280(2), and 280(3) can comprise separate units or be joined together for common deployment. When deployed as separate units, the bodies 280(1), 280(2), and 280(3) can enter through the same access point or from
As another example, as FIG. 33 shows, the body 280' can assume an egg shape when substantially inflated, to form a cavity and reshape broken bones. Other geometries, such as cylindrical or spherical, can also be used for the same purpose.
FIGS. 44 and 45 show multiple expandable zones 614 and 616 deployed in cancellous bone 620. One zone 614 serves as a platform to confine and direct the expansion of the other zone 616. For the purpose of illustration, FIGS. 44 and 45 show the
In the illustrated embodiment (as FIG. 44 shows), the first expandable body 614 is deployed through a first outer guide sheath 618(1) into cancellous bone 620 below the fracture 622. As FIG. 44 shows, when substantially expanded, the first body
614 expands more along its horizontal axis 624 (i.e., in a side-to-side direction) than along its vertical axis 626 (i.e., in an top-to-bottom direction). The greater expanded side-to-side geometry of the first body 614 compacts cancellous bone in a
relatively thin region, which extends substantially across the interior volume 628 occupied by the first body 614. The geometric limits of the body 614 will typically fall just inside the inner cortical walls of the proximal tibia, or whatever bone in
The expanded first body 614 creates a barrier 630 within the interior region 628. Due to the less expanded top-to-bottom geometry of the first body 614, a substantially uncompacted region 632 of cancellous bone is left above the body 614, which
extends from the formed barrier 630 upward to the fracture 622. In a representative deployment, the uncompacted region 632 extends about 2 cm below the tibial plateau fracture 622.
As FIG. 45 shows, the second expandable body 616 has a geometry, substantially like that shown in FIGS. 30A to 30C. When substantially inflated, the second body 616 compacts a large percentage of the cancellous bone in the region 632 above the
first expandable body 614. The presence of the barrier 630, which the expanded first body 614 creates (see FIG. 46 also), prevents expansion of the second body 616 in a direction away from the tibial platform fracture 622. Instead, the barrier 630
directs expansion of the second body 616 toward the fracture 622. Buttressed by the barrier 630, the expansion of the body 616 is directed against the fractured plateau 622, restoring it to its normal anatomic position, as FIGS. 45 and 46 show.
It should be appreciated that one or more expandable bodies can be used as platforms or barriers to direct the expansion of one or more other expandable bodies in other localized interior bone regions. The barrier makes possible localized cavity
formation in interior bone regions. Use of the barrier preserves healthy regions of cancellous bone, while directing the main compacting body toward localized fractures or localized regions of diseased cancellous bone.
FIG. 34 shows a representative embodiment of an expandable body 300 introduced inside the cortical bone 302 of the femoral head. As FIG. 34 shows, the femoral head is thin at the outer end 304 of the femur and increases in thickness at the lower
end 306 of the femur. A tube 309 directs liquid to expand the body 300. The tube 309 extends along the femoral neck and into the femoral head. The expandable body 300 compacts the cancellous bone 307 in this bone region, while also moving fractured
The femoral head is generally spherical in configuration, and the body 300 can have either a hemispherical (see FIG. 35) as well as spherical geometry (as FIG. 34 shows). The hemispherical shape is maintained in FIG. 34 by bonding overlapping
FIG. 36A shows a representative embodiment of an expandable body 410 having a "boomerang" geometry for use in preventing hip fracture. When substantially expanded (as FIG. 36A shows), the body 410 forms a cylinder, which gradually bends in the
Expansion of the body 410 is limited to achieve the described geometry by rings 430 of inelastic material. The rings 430 are held in a spaced apart relationship along one side of the body 410 by attachment to an inelastic band 416, which runs
the length of that side of body 410. The rings 430 are held in a farther spaced apart relationship along the opposite side of the body 410 by attachment to another, longer inelastic band 417, which runs the length of the opposite side of the body 410. A tube 419 conveys liquid to inflate the body 410.
Prior to deployment within the body, the body 410 is collapsed and rolled up and held against the inflation tube 419 using, for example, with frangible connectors that will break as the body is subject to expansion. To deploy the body 410 into
the hip, the surgeon uses a power drill under radiographic guidance to create a cavity 420, which is, for example, about 4 to 6 mm wide starting at the lateral femoral cortex 421 and proceeding into the femoral head 411. The body 410 is deployed through
a guide sheath 423, following the cavity 420. The body 410 is deployed, prior to expansion, facing the lesser trochanter 414, so that expansion occurs toward the femoral diaphysis 413, and not toward the greater trochanteric region 422.
The expansion of the body 410 is guided by the rings 430 and bands 416 and 417, which cause bending of the body 410 downward into the lesser trochanter 414. Optionally, a second cavity can be drilled down into the diaphysis 413, starting from
The body length is chosen by the physician to extend about 0.5 cm from the end of the femoral head, through the femoral neck and into the proximal femoral diaphysis, usually about 4 to 8 cm below the lesser trochanter. The body diameter is
chosen by measuring the inner cortical diameter of the femoral neck (the most narrow area) and subtracting 0.5 cm. The preferred dimensions of the body 410 are a total length of 10-20 cm and a diameter of about 1.0-2.5 cm.
(inserted at the same point and expanded prior to inserting any supporting material). Alternatively, the bent body 410 may be adapted to have a distal portion that approximates the shape of the femoral head body.
The geometry of the single, restrained body 410 can be approximated by multiple expandable bodies deployed separately, or coupled together, or stacked together. FIG. 36B shows a representative embodiment of the use of multiple expandable bodies
As FIG. 36B shows, a first expandable body 410(1) is introduced through a first outer guide sheath 423(1) in the proximal lateral cortex of the femoral shaft. The first body 419(1) is deployed across the femoral neck 480 into the femoral head
One or both of the bodies 410(1) and 410(2) can include external restraints to limit expansion, in the manner described with regard to the body 410. Expansion of the bodies 410(1) and 410(2) compacts cancellous bone to form a cavity having a
In FIG. 37A, the body 450 is deploy into the calcaneus 452 by a posterior approach, through the tuberosity. Other approaches can be used, as desired by the physician. A power drill opens a passage 466 through the tuberosity into the calcaneus. An outer guide sheath 470 is positioned within the passage 466, abutting the posterior of the calcaneus, in the manner previously described in obtaining access to a vertebral body. The body 450 is introduced through the guide sheath 470 and formed
Expansion of the body 450 is limited within the confines of the calcaneus by inelastic peripheral bands 454 (see FIG. 37B). The bands 454 constrain expansion of the body 450 to an asymmetric, pear-shaped geometry, best shown in FIG. 37B. The
pear-shaped geometry has a major dimension Hi occupying the region of the posterior facet 454. The major dimension Hi is located here, because the part of the calcaneus most likely to require elevation and realignment during expansion of the body 450 is
Expansion of the body 410 compacts cancellous bone 470 within the calcaneus 452. The expansion also lifts a depression fracture of the posterior facet 454 back to or near its original anatomic elevation adjacent the talus 456. When collapsed
FIG. 38 shows another representative embodiment of an expandable body 450' for use in treating fractures in the calcaneus. The body 450' in FIG. 38 has a more spherical or egg-shaped geometry than the pear-shaped body 450 shown in FIG. 37B. Like the pear-shaped body 450, the body 450', when expanded within the calcaneus, forms a cavity within cancellous bone and realigns fractured cortical bone at or near its normal anatomic position.
The choice of the shape and size of a expandable body takes into account the morphology and geometry of the site to be treated. As before stated, the shape of the cancellous bone to be compressed, and the local structures that could be harmed if
bone were moved inappropriately, are generally understood by medical professionals using textbooks of human skeletal anatomy along with their knowledge of the site and its disease or injury. Precise dimensions for a given patient can be further
fracture) is the loss of cancellous bone mass (as in osteoporosis). The preferred range is about 30% to 90% of the cancellous bone volume. Compacting less of the cancellous bone volume can leave too much of the diseased cancellous bone at the treated
site. The diseased cancellous bone remains weak and can later collapse, causing fracture, despite treatment.
Another general guideline for the selection of the geometry of the expandable body is the amount that the targeted fractured bone region has been displaced or depressed. The expansion of the body within the cancellous bone region inside a bone
However, there are times when a lesser amount of cancellous bone compaction is indicated. For example, when the bone disease being treated is localized, such as in avascular necrosis, or where local loss of blood supply is killing bone in a
limited area, the expandable body can compact a smaller volume. This is because the diseased area requiring treatment is smaller.
Another exception lies in the use of an expandable body to improve insertion of solid materials in defined shapes, like hydroxyapatite and components in total joint replacement. In these cases, the body shape and size is defined by the shape and
Yet another exception is the delivery of therapeutic substances, which will be described in greater detail later. In this case, the cancellous bone may or may not be diseased or adversely affected. Healthy cancellous bone can be sacrificed by
significant compaction to improve the delivery of a drug or growth factor which has an important therapeutic purpose. In this application, the size of the expandable body is chosen by the desired amount of therapeutic substance sought to be delivered. In this case, the bone with the drug inside is supported while the drug works, and the bone heals through exterior casting or current interior or exterior fixation devices.
placement or in a vertebral body, where the spinal cord is nearby. Using relatively inelastic bodies, the shape and size can be better predefined, taking into account the normal dimensions of the outside edge of the cancellous bone. Use of relatively
inelastic materials also more readily permits the application of pressures equally in all directions to compress cancellous bone. Still, substantially equivalent results can usually be achieved by the use of multiple expandable bodies having highly
FIGS. 39A to 39D show a multiple stage process for introducing filling material into a cavity formed by an expandable body in cancellous bone. The process is shown in association with treating a vertebral body. This is for the purpose of
illustration. It should be appreciated that the process can be used in the treatment of all bone types.
Use of the multi-stage process is indicated when pre-examination of the targeted bone reveals that a portion of the cortical wall 28 has fractured or failed (as FIG. 39A shows at the anterior region of the vertebral body 26). The failed cortical
wall 28 creates gaps and cracks (designated G in FIG. 39A). Typically, remnant chips 500 of the failed cortical bone 28 may lay in the cancellous bone 32 in the region where cortical wall failure has occurred. Filling material can flow or seep through
The process begins at the point where the outer guide sheath 72 has been positioned and the guide pin removed in the manner previously described. The physician introduces a first expandable body 502 into the cancellous bone 32 near the failed
cortical bone region, as FIG. 39A shows. The first expandable body 502 is sized, when substantially expanded, to occupy a relatively small volume (i.e., less than about 20%) of the volume of cancellous bone 32 in interior volume 30.
In a short time interval (before the filling material 96(1) is allowed to substantially set and harden), the physician withdraws the injector tip 90 and introduces a second expandable body 506 into the cancellous bone 32 (see FIG. 39C). The
second expandable body 506 is larger than the first body 502. The second body 506 is sized to create the desired geometry for the therapeutic main cavity 508 in cancellous bone 32.
As FIG. 39C shows, expansion of the second body 506 displaces the earlier injected aliquot of filling material 96(1) in the cavity 504 toward the failed cortical wall region. The aliquot of filling material 96(1) will envelop remnant chips 500
of cortical bone lying in its path. The material 96(1) and enveloped chips 500 are pressed against the failed cortical bone region as expansion of the second body 506 progresses. The first aliquot of filling material 96(1) will begin to set and harden
as the main therapeutic cavity 508 is being formed by the expansion of the second body 506. The second body 506 is collapsed and removed, leaving the main cavity 508.
As FIG. 39D shows, the first aliquot of filling material 96(1) provides a viscous or (in time) hardened boarder region along the anterior edge of the cavity 508. As subsequent injection of additional filling material 96(2) into the main cavity
508 proceeds, as FIG. 39D shows, the viscous or hardened boarder region 96(1) impedes passage of the additional filling material 96(2) as it fills the main cavity 508. The viscous or hardened boarder region 96(1) serves as a dam, keeping the additional
FIGS. 40 and 41 show the use of an interior mesh 510 in association with the introduction of filling material into a cavity formed by an expandable body in cancellous bone. The mesh 510 is shown in association with treating a vertebral body, but
disease or a complex fracture, to adequately fill the failed cortical bone region by compacting using an expandable body. Flowable cement material can flow or seep through the unfilled gaps or cracks (designated G in FIG. 41) present in the failed
The mesh 510 comprises a woven structure made from biocompatible material like Goretex.TM. material, Nitinol.TM. material, or Dacron.TM. material. The mesh presents a surface area, which is about 1/3rd to 1/2 of the interior area of the main
Before deploying the injector tip 90 into the formed cavity 84 (which is deployed in FIG. 41 by posterolateral access), the physician drapes the mesh 510 over the tip 90, as FIG. 40 shows. As FIG. 41 shows, the viscous flow of filling material
96 injected from the tip 90 carries the mesh 510 into the cavity 84 in advance of the filling material 96. The mesh 510 is urged by the filling material 96 into contact with the anterior region of the bone, including the failed cortical bone region. The mesh 510, permeated with viscous material 96 and resting over the failed cortical bone region, impedes passage of filling material, until hardening occurs.
An expandable body can compact infected cancellous bone to create a space which can be filled with the antibiotic gel in an open or minimally invasive procedure. The cavity places and holds the required amount of drug right at the site needing
Not only can the dose be optimized, but additional doses can be applied at later times without open surgery, enhancing the therapeutic outcome. If the required cavity for the optimal drug dose weakens the bone, the bone can be protected from
The therapeutic substance put into bone may act outside the bone as well. A formulation containing chemotherapeutic agent could be used to treat local solid tumors, localized multiple myeloma or even a nearby osteosarcoma or other tumor near
The cavity formed by an expandable body can be filled with an appropriate supporting material, like acrylic bone cement or biocompatible bone substitute, which carries a therapeutic substance. Alternatively, the therapeutic substance can be
separately delivered before injection of the filling material. Thus, using an expandable body, the physician is able to treat a fracture while also delivering a desired therapeutic substance (like an antibiotic, bone growth facer or osteoporosis drug)
agent to coat the body with the above-mentioned substance before it is inserted into a bone being treated. Optionally, the body can be wholly or partially expanded before the coating is performed. optionally, the coated body can be dried with air or by
other means when the applied formulation is wet, such as a liquid or a gel. The body is refolded as required and either used immediately or stored, if appropriate and desired. Coated on the body, therapeutic substances can be delivered while cancellous
The methods described above can also be used to coat Gelfoam or other agents onto the body before use. Inflating the Gelfoam-coated body inside bone will further fill any cracks in fractured bone not already filled by the compressed cancellous
FIGS. 42A to 42C schematically illustrate one system and method for delivering a therapeutic substance to the bone using an expandable body 529. The body 529 is carried at the end of the catheter tube 530, which conveys liquid to expand the body
As shown in FIG. 42A, the expandable body 529, in a substantially expanded condition, is stabilized with a clip 531 that couples the catheter tube 530 to a wire 532. As shown in FIG. 42B, a measured amount of gel formulation containing the
desired amount of substance 533 is uniformly dispensed from a container 534, preferably in thin lines 535, onto the outer surface of the body 536. The coating substance can be the desired compound alone in its natural state (solid, liquid or gas) or in
an appropriate formulation, including a dry powder, an aerosol or a solution. As shown in FIG. 42C, the coated body 537 is collapsed and allowed to dry until the gel sets. Alternatively, the body 536 can also be coated without prior expansion. The
optional drying time will, of course, depend on the nature of the compound and its formulation. The coated body 237 is suitable for packaging for use by a surgeon.
Delivering a therapeutic substance on the outside of expandable body used to compact the bone, or with an expandable body introduced after the bone is compacted, is qualitatively different than putting formulated drug into the cavity. When
delivered while the bone is compressed, the therapeutic substance becomes incorporated into the compacted bone. This can serve as a way to instantly formulate a slow release version of the substance.
For example, the cavity can accommodate a typical dose of the antibiotic, gentamicin, to treat a local osteomyelitis (bone infection). A typical dose is about 1 gram, although the therapeutic range for gentamicin is far greater, from 1 nanogram
to 100 grams, depending on the condition being treated and the size of the area to be covered. A medically-suitable gel formulated with appropriate gel materials, such as Polyethylene glycol, can contain 1 gram of gentamicin in a set volume of gel, such
Other antibiotics that can be used to treat bone infection include, for example, ancef, nafcillin, erythromycin, tobramycin, and gentamicin. Typical bone growth factors are members of the Bone Morphogenetic Factor, Osteogenic Protein, Fibroblast
Growth Factor, Insulin-Like Growth Factor and Transforming Growth Factor alpha and beta families. Chemotherapeutic and related agents include compounds such as cisolatin, doxcrubicin, daunorubicin, methotrexate, taxol and tamoxifen. Osteoporosis drugs
the minimally-invasive procedure. During open surgery, the physician can approach the bone in the same way.
The system 700 employs a bone marrow harvesting tool 704. The tool 704 includes a catheter tube 706, which carries an expandable body 708 at its distal end. The tool 704 can be deployed into the bone 702 using a minimally invasive approach, as
The catheter tube 706 has three concentric and independent lumens 710, 712, and 714 (see FIG. 48). The outer lumen 710 communicates with the interior of the body 78 and is coupled to a source 718 of an inflation liquid. The middle lumen 712
communicates with a source 720 of rinse liquid and a distal opening 716 on the catheter tube 706. The center lumen 714 communicates with a collection container 722 and a second distal opening 724 on the catheter tube 706.
As FIG. 48 shows, the body 708 is constrained by selection of relatively inelastic materials or by exterior restraints (as previously described) to assume an elongated shape. Expansion of the body 708 creates a relatively shallow area of
compaction 726 in cancellous bone 728 along a relatively long length. The size and shape of the body 708 will depend upon the geometry of the harvest site and the amount of bone marrow required. In long bones, like the distal radius, and in bones with
As FIG. 48 also shows, as the body 708 expands, rinse liquid, which can be saline or another suitable biocompatible liquid, is conveyed from the source 720 into the area 726 (shown by arrows 730 in FIG. 48). The rinse liquid loosens up
biological components (such as red blood cells, bone cells, and immune-.beta. cells) within the defined area 726, forming component-rich suspension 732.
The above sequence of expansion, rinsing, collapse, and aspiration can be repeated to collect additional component-rich suspension 732 in the container 722. The position of the expandable body 708 in the bone 702 can be changed, if desired, to
Use of the expandable body 708 to form the long but shallow compaction area 726 permits the harvest of a significant concentration of therapeutic biological components with less damage to bone that conventional harvesting methods. If desired,