The invention relates to the treatment of bone conditions in humans and other animals.
There are 2 million fractures each year in the United States. There are also other bone diseases involving infected bone, poorly healing bone, or bone fractured by severe trauma. These conditions, if not successfully treated, can result in deformities, chronic complications, and an overall adverse impact upon the quality of life.
The invention provides improved systems and methods for treating bone using one or more expandable bodies. The systems and methods insert an expandable body in a collapsed configuration into a space defined between cortical bone surfaces. The space can, e.g., comprise a fracture or an intervertebral space left after removal of the disk between two vertebral bodies. The systems and methods cause expansion of the expandable body within the space, thereby pushing apart the cortical bone surfaces. The expansion of the body serves, e.g., to reduce the fracture or to push apart adjacent vertebral bodies as part of a therapeutic procedure, so that healing can occur without deformity.
Features and advantages of the inventions are set forth in the following Description and Drawings, as well as in the appended Claims.
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 to be embraced by the claims.
The use of expandable bodies to treat bones is disclosed in U.S. Pat. Nos. 4,969,888 and 5,108,404. The systems and methods disclosed in these patents treat bone from the inside out. That is, the systems and methods deploy an expandable body into the interior volume of the bone. Expansion of the body inside the bone compacts or compresses surrounding cancellous bone. The compaction of cancellous bone inside the bone exerts interior force upon outside cortical bone, making it possible to elevate or push broken and compressed cortical bone back to or near its original prefracture position.
There are times, however, when fracture reduction is indicated by applying external pressure directly on cortical bone surfaces.
According to the invention (as
Access can be achieved either with a closed, mininimally invasive procedure or with an open procedure.
The materials for the catheter tube 22 are selected to facilitate advancement of the body 20 into position against the cortical bone surfaces 18 through the cannula 24. The catheter tube 22 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 22 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™ material, PEBAX™ material, stainless steel, nickel-titanium alloys (Nitinol™ material), and other metal alloys.
The body 20 is caused to assume an expanded geometry within the fracture 16, which is shown in FIGS. 5 and 6. To provide expansion of the body 20, the catheter tube 22 includes an interior lumen 28. The lumen 22 is coupled at the proximal end of the catheter tube 22 to a source of fluid 30. The fluid 30 is preferably radio-opaque to facilitate visualization. For example, Renograffin™ can be used for this purpose.
The lumen 28 conveys the fluid 30 into the body 20. As fluid 30 enters the body 20, the body 20 expands, as
Expansion of the body 20 exerts pressure directly against surrounding the cortical bone surfaces 18. The pressure exerted by expanding body 20 moves surrounding the cortical bone surfaces 18 apart at the fracture 16. The exerted pressure lifts surrounding cortical bone surfaces 18 at the fracture 16 (shown by arrow 26 in
As
The catheter tube 42 includes an interior lumen 48, which is coupled at the proximal end of the catheter tube 42 to a source of fluid 50 (which is preferably radio-opaque, such as Renograffin™). The lumen 48 conveys the fluid 50 into the body 38 to cause it to expand. As
It should be appreciated that, in the embodiments shown, the use of more than one expandable body 20 or 38 may be indicated to move the targeted surfaces of cortical bone apart. For example, as
The material of the expandable body or bodies used 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 expandable body or bodies 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 with generally elastic or generally semi-elastic properties, the physician monitors the expansion to assure that over-expansion and body failure do not occur. Furthermore, expandable bodies with generally elastic or generally semi-elastic properties may require some form of external or internal restraints. For example, the material for the body can be selected to exhibit more inelastic properties, to limit expansion of the wall 58 prior to wall failure. The body can also include one or more restraining materials, particularly when the body is itself made from more elastic materials. The restraints, made from flexible, inelastic high tensile strength materials, limit expansion of the body prior to failure.
When relatively inelastic materials are used for the body, or when the body is otherwise externally restrained to limit its expansion prior to failure, a predetermined shape and size can be imparted to the body, when it is substantially expanded. The shape and size can be predetermined according to the shape and size of the surrounding cortical bone. The shape of the surrounding cortical bone and the presence of surrounding local anatomic structures are generally understood by medical professionals using textbooks of 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 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 objective is to push cortical bone surfaces apart to meet the therapeutic objectives without harm. By definition, harm results when expansion of the body results in a worsening of the overall condition of the bone and surrounding anatomic structures, for example, by injury to surrounding tissue or causing a permanent adverse change in bone biomechanics.
It should be appreciated that expandable bodies as described possess the important attribute of being able to push apart cortical bone in fractured or deformed bone structures, back to or near normal anatomic position. This attribute makes these expandable bodies well suited for the successful treatment of fractures or deformities in the spine, as well as throughout the appendicular skeleton, such as the distal radius, the proximal humerus, the tibial plateau, the femoral head, hip, and calcaneus.
The features of the invention are set forth in the following claims.
This application is a divisional of co-pending U.S. patent application Ser. No. 11/656,158, filed Jan. 22, 2007 and entitled “Systems and Methods Using Expandable Bodies to Push Apart Cortical Bone Surfaces,” which is a divisional of co-pending U.S. patent application Ser. No. 10/010,576, filed Nov. 13, 2001, and entitled “Systems and Methods Using Expandable Bodies to Push Apart Cortical Bone Surfaces” (now U.S. Pat. No. 7,166,121), which is continuation of U.S. patent application Ser. No. 08/986,876, filed Dec. 8, 1997 (now abandoned), which is a continuation-in-part of U.S. patent application Ser. No. 08/871,114, filed Jun. 9, 1997 and entitled “Systems and Methods for Treatment of Fractured or Diseased Bone Using Expandable Bodies” (now U.S. Pat. No. 6,248,110), which is a continuation-in-part of U.S. patent application Ser. No. 08/659,678, filed Jun. 5, 1996 (now U.S. Pat. No. 5,827,289), which is a continuation-in-part of U.S. patent application Ser. No. 08/485,394, filed Jun. 7, 1995 (now Abandoned), which is a continuation-in-part of U.S. patent application Ser. No. 08/188,224, filed Jan. 26, 1994 entitled, “Improved Inflatable Device For Use In Surgical Protocol Relating To Fixation Of Bone” (now Abandoned), all of which are incorporated herein by reference.
Number | Date | Country | |
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Parent | 11656158 | Jan 2007 | US |
Child | 11978373 | Oct 2007 | US |
Parent | 10010576 | Nov 2001 | US |
Child | 11656158 | Jan 2007 | US |
Number | Date | Country | |
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Parent | 08986876 | Dec 1997 | US |
Child | 10010576 | Nov 2001 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 08871114 | Jun 1997 | US |
Child | 08986876 | Dec 1997 | US |
Parent | 08659678 | Jun 1996 | US |
Child | 08871114 | Jun 1997 | US |
Parent | 08485394 | Jun 1995 | US |
Child | 08659678 | Jun 1996 | US |
Parent | 08188224 | Jan 1994 | US |
Child | 08485394 | Jun 1995 | US |