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The present disclosure is directed towards positioning instruments and related methods for implanting an energy absorbing system, and more particularly to tools and surgical procedures for implanting an energy absorbing system for treating joint members.
Joint replacement is one of the most common and successful operations in modern orthopedic surgery. It consists of replacing painful, arthritic, worn or diseased parts of a joint with artificial surfaces shaped in such a way as to allow joint movement. Osteoarthritis is a common diagnosis leading to joint replacement. Such procedures are a last resort treatment as they are highly invasive and require substantial periods of recovery and permanently alter the joint. Total joint replacement, also known as total joint arthroplasty, is a procedure in which all articular surfaces at a joint are replaced. This contrasts with hemiarthroplasty (half arthroplasty) in which only one bone's articular surface at a joint is replaced and unincompartmental arthroplasty in which the articular surfaces of only one of multiple compartments at a joint (such as the surfaces of the thigh and shin bones on just the inner side or just the outer side at the knee) are replaced.
Arthroplasty as a general term, is an orthopedic procedure which surgically alters the natural joint in some way. This includes procedures in which the arthritic or dysfunctional joint surface is replaced with something else, and procedures which are undertaken to reshape or realign the joint by osteotomy or some other procedure. As with joint replacement, these other arthroplasty procedures are also highly invasive procedures characterized by relatively long recovery times. A previously popular form of arthroplasty was interpositional arthroplasty in which the joint was surgically altered by insertion of some other tissue like skin, muscle or tendon within the articular space to keep inflammatory surfaces apart. Another previously done arthroplasty was excisional arthroplasty in which articular surfaces were removed leaving scar tissue to fill in the gap. Among other types of arthroplasty are resection(al) arthroplasty, resurfacing arthroplasty, mold arthroplasty, cup arthroplasty, silicone replacement arthroplasty, and osteotomy to affect joint alignment or restore or modify joint congruity. When successful, arthroplasty results in new joint surfaces which serve the same function in the joint as did the surfaces that were removed. Any chondrocytes (cells that control the creation and maintenance of articular joint surfaces), however, are either removed as part of the arthroplasty, or left to contend with the resulting joint anatomy. Because of this, none of the therapies which remove the joint surfaces are chondro-protective.
A widely-applied type of osteotomy is one in which bones are surgically cut to improve alignment. A misalignment due to injury, bone abnormality or disease in a joint relative to the direction of load can result in an imbalance of forces and pain in the affected joint. The goal of osteotomy is to surgically re-align the bones at a joint and thereby relieve pain by shifting forces across the joint to less damaged joint surfaces. This can also increase the lifespan of the joint. When addressing osteoarthritis in the knee joint, this procedure involves surgical re-alignment of the joint by cutting and reattaching part of one of the bones at the knee to change the joint alignment, and this procedure is often used in younger, more active or heavier patients. Most often, high tibial osteotomy (HTO) (the surgical re-alignment of the upper end of the shin bone (tibia) to address knee malalignment) is the osteotomy procedure done to address osteoarthritis and it often results in a decrease in pain and improved function. However, HTO does not address ligamentous instability—only mechanical alignment. HTO is associated with good early results, but results deteriorate over time.
It has been found that excess loading of the joint is the primary contributing factor in the progression of osteoarthritis disease. It has also been shown that a decrease in load, such as by weight loss can result in decrease in disease progression and in pain relief.
Certain approaches to treating osteoarthritis contemplate external devices such as braces or fixators which attempt to control the motion of the bones at a joint or apply cross-loads at a joint to shift load from one side of the joint to the other. A number of these approaches have had some success in alleviating pain by reducing loads on diseased joints but have ultimately been unsuccessful due to lack of patient compliance or the inability of the devices to facilitate and support the natural motion and function of the diseased joint.
Certain prior approaches to treating osteoarthritis have also failed to account for all of the basic functions of the various structures of a joint in combination with its unique movement. In addition to addressing the loads and motions at a joint, an ultimately successful approach should both acknowledge the dampening and energy absorption functions of the anatomy, and be implantable via a minimally invasive technique. Device constructs which are relatively rigid do not allow substantial energy storage. For these relatively rigid constructs, energy is transferred rather than stored or absorbed relative to a joint. By contrast, the natural joint is a construct comprised of elements of different compliance characteristics such as bone, cartilage, synovial fluid, muscles, tendons, ligaments, etc. as described above. These dynamic elements include relatively compliant ones (ligaments, tendons, fluid, cartilage) which allow for substantial energy absorption and storage, and relatively stiffer ones (bone) that allow for efficient energy transfer. The cartilage in a joint compresses under applied force and the resultant force displacement product represents the energy absorbed by cartilage. The fluid content of cartilage also acts to stiffen its response to load applied quickly and dampen its response to loads applied slowly. In this way, cartilage acts to absorb and store, as well as to dissipate energy.
Approaches for surgically implanting extra-articular mechanical energy absorbing apparatus have been developed. As precise and effective placement are important to the efficacy of an implanted extra-articular mechanical absorbing apparatus, further advancements in patient preparation and device-to-anatomy juxapositional relationships have been found to be both useful and necessary.
With the foregoing applications in mind, it has been found to be necessary to develop effective systems and tools for mounting an extra-articular energy absorbing apparatus to body anatomy.
For energy absorbing apparatus to function optimally, they must not cause an adverse disturbance to joint motion. Therefore, what is needed is a refined surgical approach to implanting a device which addresses both joint movement and varying loads as well as complements underlying or adjacent anatomy.
The present disclosure satisfies these and other needs.
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OF THE DISCLOSURE
Briefly and in general terms, the present disclosure is directed towards treating diseased or mal-aligned body joints, typically affected by osteoarthritis, using an energy absorbing system without limiting the range of motion of the patient's articulating joint. The positioning instruments and related methods are described herein for implanting such energy absorbing system.
A method of implanting a device at a joint comprising inserting a first reference marker into a first bone of the joint, inserting a second reference marker into a second bone of the joint, connecting the first and second reference markers to a verification tool, moving the joint through a predetermined range of motion and utilizing the verification tool to determine whether the first and second reference markers move in a desired kinematic pattern with respect to one another throughout the predetermined range of motion, relocating one of the reference markers if the desired kinematic pattern is not achieved, and implanting the device across the joint.
A verification tool for verification of a location for implantation of an extra-articular energy absorbing device at a joint, the tool comprising a tool body, a first connection member on the tool body, the first connection member configured to be connected to a first reference marker located in a first bone, the first connection member allowing rotation of the tool with respect to the first bone, a second connection member on the tool body, the second connection member configured to be connected to a second reference marker located in a second bone, the second connection member allowing rotation of the tool with respect to the second bone, wherein at least one of the first and second connection members is movable with respect to the tool body, and a gauge configured to provide a user with information about the location of at least one of the first and second reference markers as the joint is articulated.
A system for placing an energy absorbing device at a joint comprising a base configured to be secured to a bone adjacent a joint, a placement guide removably attachable to the base, wherein the placement guide includes an offset member one end of which is connected to the placement guide and an opposite end of which is configured to contact the bone.
A method for locating a center of rotation for an implantable articulating joint device, the method comprising locating an anatomical reference location on a bone with a tool having radiopaque markers, and marking a target location for an implantable articulating joint device at a predetermined distance and direction away from the anatomical reference location by inserting a marker through an opening in the tool.
A method of implanting an energy absorbing device at a joint comprising securing a first base member to a bone on a first side of a joint, affixing an absorber to the first base member, the absorber having at least one articulation, temporarily restraining the articulation of the absorber to a limited range of motion less the a full range of motion of the articulation with a removable restraint, positioning and securing a second base member to a bone on a second side of the joint while the articulation of the absorber is temporarily restrained, and removing the restraint.
A system for placing an energy absorbing device at a joint comprising a base configured to be secured to a bone adjacent a joint and including a first placement guide mounting surface and a first connector component, a placement guide including a second placement guide mounting surface, a second connector component adapted to mate with the first connector component, and an offset member, the placement guide being attachable to the base in an attached position such that the first and second placement guide mounting surfaces abut when the first and second connector components mate.
A method for positioning a base for an implant at a joint, comprising inserting a first elongated reference marker into a first bone of the joint so that one end of the first reference marker is inserted into the bone and the other end of the first reference marker is free, placing a preassembled combination of a base and a placement guide on the bone of the joint so that the first reference marker extends through a first guide hole in the placement guide, inserting a second elongated reference marker through a second guide hole in the placement guide and into the bone of the joint while orienting the combination and the second reference marker so that, when the second reference marker is inserted into the bone, the second reference marker extends in a predetermined relation to the first bone and a second bone of the joint.
A tool for selecting one base from among a plurality of bases having different base geometries for an implant at a joint, comprising, a tool body having a bone contacting surface shape generally corresponding to a bone contacting surface shape of the plurality of bases from which the one base is to be selected, a guide opening on the tool body through which an elongated reference marker is adapted to extend, indicia corresponding to at least some of the plurality of bases, wherein, when the tool body is positioned on a bone of the joint so that the reference marker extends through the guide opening and the tool body is in a desired alignment with the bone, the reference marker is disposed in a position relative to the indicia that indicates one base is to be selected.
A method for selecting a base from among a plurality of bases having different base geometries for an implant at a joint, comprising, inserting an elongated reference marker into a bone of the joint so that one end of the reference marker is inserted into the bone and the other end of the reference marker is free, positioning a trial so that a surface of the trial is in a desired alignment with the portion of the bone and so that the free end of the reference marker extends through a guide opening on the trial, and selecting one base from among the plurality bases depending upon a position of the reference marker relative to one or more indicia associated with the guide opening.
Other features of the energy absorbing system and device will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
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FIG. 1 is a perspective view, depicting an extra-articular implantable mechanical energy absorbing system;
FIG. 2 is a side view, depicting the absorber of the system of FIG. 1 with the sheath removed;
FIG. 3 is a side view, of a position verification tool for location of a correct position for the energy absorbing system of FIG. 1;
FIG. 4 is a perspective view, of the verification tool of FIG. 3 in use on a patient;
FIG. 5 is a perspective view, of the verification tool of FIG. 3;
FIG. 6A is a perspective view of a bullseye tool for inserting a reference marker into a bone at a desired location;
FIG. 6B is a top view of a portion of the bullseye tool of FIG. 6A;
FIG. 7A is a top perspective view of a placement guide used to facilitate correct positioning of the base;
FIG. 7B is a side perspective view of the placement guide of FIG. 7A;
FIG. 8 is a top view of the placement guide of FIG. 7A temporarily attached to a base;