Source: https://patents.google.com/patent/RU2513155C2/en
Timestamp: 2019-11-19 01:19:35
Document Index: 388693699

Matched Legal Cases: ['Application No. 20080140075', 'Application No. 20080097457', 'Application No. 20080140075', 'Application No. 20080140075', 'Application No.20080097457', 'application No. 20050131422', 'Application No. 10', 'application No. 20050131421', 'application No. 10', 'art 107']

RU2513155C2 - System and method for spine stabilisation using wired pedicle screw - Google Patents
System and method for spine stabilisation using wired pedicle screw Download PDF
RU2513155C2
RU2513155C2 RU2011113701/14A RU2011113701A RU2513155C2 RU 2513155 C2 RU2513155 C2 RU 2513155C2 RU 2011113701/14 A RU2011113701/14 A RU 2011113701/14A RU 2011113701 A RU2011113701 A RU 2011113701A RU 2513155 C2 RU2513155 C2 RU 2513155C2
RU2011113701/14A
RU2011113701A (en
Шервин ХУА
2009-09-30 Application filed by Шервин ХУА filed Critical Шервин ХУА
2012-11-10 Publication of RU2011113701A publication Critical patent/RU2011113701A/en
2014-04-20 Publication of RU2513155C2 publication Critical patent/RU2513155C2/en
230000003019 stabilising Effects 0 abstract title 3
SUBSTANCE: group of inventions refers to medicine. A bone stabilisation system comprises a first screw with a first screw head, a second screw with a second screw head, a spinal fastener, at least a first guide element and at least a second guide element. The spinal fastener is provided to be kept in the first and second screw heads. At least the first guide element extends from the first screw and can pass through a skin hole through which it has been introduced. At least the second guide element extends from the second screw and can pass through the skin hole. The first and second guide elements can overlap, and if overlapped, guide the spinal fastener until it contacts the first and second screw heads at an angle formed by the guide elements, including an angle non-parallel with the long axis of the both guide elements. The above screw used for the bone stabilisation comprises a screw column, a screw head with a support and at least one wire. The above support limits a canal receiving the spinal fastener. at least one wire extends from the screw head and is configured so that to direct the spinal fastener into the canal of the screw head support.
EFFECT: group of inventions provides a simple method of placing two or more pedicle screws using a small hole, better cosmetic and functional results using only a single small skin incision (about one to two cm long) irrespective of the number of the used screw, and a possibility to insert, place and manipulate a rod and a locking mechanism through the same small incision for the purpose of locking the rod inside the screws.
The present invention relates to medical devices, systems and methods for fixing bone. In particular, the invention is aimed at stabilizing neighboring vertebrae in the cervical, thoracic and lumbosacral spine. More specifically, the invention is directed to the implementation of spinal fusion or stabilization of the vertebrae in the lumbar spine in order to alleviate axial back pain. More specifically, the invention is aimed at improving minimally invasive surgical approaches to spinal fusion with transpedicular screws by reducing the number and size of incisions, as well as the size of the medical instruments inserted into them.
Some diseases of the lower back can be successfully treated with non-surgical methods, but spinal fusion is recommended for certain diseases when non-surgical methods are ineffective. Non-surgical methods include medication, physiotherapy, manual therapy, traction, epidural steroid administration, facet blocks or rhizotomy, weight loss, smoking cessation, and acupuncture. Diseases that usually indicate the need for spinal fusion or stabilization surgery can be divided into three general categories: (i) resulting from trauma, (ii) curvature, and (iii) degenerative.
Diseases caused by trauma include fractures and damage to ligaments. Fractures are usually the result of an accident and occur under the influence of external force or as a result of a fall, but can also be the result of pathological conditions such as cancer or osteoporosis. Fractures often have a compression nature and usually lead to pathological curvature of the spine, leading to the loss of natural lordosis in the lumbar and cervical spine, otherwise called kyphosis. Fractures of the spine also occur under the influence of translational or rotational forces applied perpendicular to the axis of the spine. The indicated forces lead to fractures of the facet or inter-articular parts. If the external forces are strong enough, the vertebrae can collapse, leading to an explosive fracture that can damage all three vertebral columns (front, middle and back column). Many traumatic injuries can be healed without surgery, but unstable lesions that carry a risk of neurological damage and / or pain require stabilization using a procedure such as spinal fusion.
A disease called spondylolisthesis, which is characterized by slipping of the bones of the spine or vertebrae relative to each other, may result from a fracture of the inter-articular parts called spondylolysis. Spondylolisthesis can also develop due to deformation of the arched joints due to degenerative arthritis, as well as due to congenital malformations and pathological conditions such as tumors. If the inter-articular parts are broken on both sides, the spinous process and the plate are essentially completely separated from the arch and body of the vertebra. This large fragment is called the body of Gill. Fractures of the interarticular parts are widespread in people of all ages (often they were received in adolescence). And despite the fact that in many patients the symptoms are mild and do not require surgical intervention, patients with progressive symptoms may need surgical decompression with or without spinal fusion. Spondylolisthesis leads to a deviation of the spine from the axis and increases the risk of pinching the nerve. Nerves pass inside the spinal canal, bounded by the vertebrae, and their roots exit from the curved openings in the lateral sides of the vertebrae called vertebral openings. It is assumed that these vertebral nerves are a source of back pain and radiculitis if they are pinched or if the nerve endings are irritated due to an uneven or sudden movement in the region of the disk, bone or joint. Spondylolisthesis may also be accompanied or enhanced by degeneration of the disc or the arched joint, which can lead to axial back pain.
The natural curvature of the lumbar and cervical spine is called lordosis, in which the back of these sections forms a concave bend. The thoracic spine normally has a kyphotic, or convex, bend. Diseases of these bends include straightening of the natural bend, as well as abnormal lordosis, abnormal kyphosis, or lateral / rotational curvature called scoliosis. Bend diseases can occur idiopathically in adolescence, i.e. adolescent idiopathic scoliosis, or develop as a secondary problem in situations where abnormal work of the muscles of the spine occurs, for example, with cerebral palsy, vertebral cleft or stretched spinal cord syndrome. Abnormal curvature of the spine is common during spinal degeneration, when the discs and joints degenerate asymmetrically, leading to progressive curvature (scoliosis, kyphosis or lordosis) due to a violation of the biomechanics of the spine. Bend disease also occurs after injuries associated with compression or blast fractures or damage to ligaments. In addition, bending diseases can occur iatrogenically after a previous vertebral surgery, during which the anatomy and biomechanics of the spine were changed. Such cases include the removal of the posterior bandage after laminectomy, as well as the change in physiological movement after spinal fusion, leading to compensation of the adjacent level and degeneration. Bending diseases lead to abnormal biomechanical pressure on the discs and arched joints, followed by compensatory measures such as joint or ligament hypertrophy. Patients may show both axial back pain and radiculitis. Surgery may be effective for patients who are not affected by traditional therapy and fixation. In these cases, surgery includes nerve decompression or spinal cord compression, as well as spinal fusion or stabilization. Curvature can be corrected surgically, and fusion prevents further aggravation of the curvature.
Degenerative diseases include vertebral arthritis and recurrent vertebral hernia. Vertebral arthritis most often indicates the need for spinal fusion and can exist in the form of significant degeneration of the disc (also called degenerative disc disease) or arterial disease. Degenerative arthritis can also cause spondylolisthesis in addition to the traumatic fractures described above. Degenerative diseases are usually accompanied by compression of the nerve, leading to radiculitis in the area of the receptor field of the nerve, which usually corresponds and is expressed as pain in the arms or legs. Exceptional nerve compression syndromes such as herniation of nucleus propulsus (herniation of the spinal disc) or foraminal stenosis (narrowing of the lateral spinal canals through which the nerves pass) can often be treated with decompression without spinal fusion. Exceptional disc degeneration syndromes can be treated with spinal fusion without nerve decompression. However, most often, disk degeneration occurs in conjunction with compression of the nerves, causing both axial back pain and radiculitis pain in the extremities. In such cases, fusion is combined with decompression of the nerves.
Spinal fusion eliminates the movement in the space of the disk and the arched joints between adjacent vertebrae. The vertebrae provide a rigid structural shell of the spine, and the fibro-cartilage space of the disk acts as a pillow or shock absorber. Degradation of the disk space can distort the orientation and change the biomechanical pillow, which is provided by the adjacent vertebrae by the disk. The specified degradation changes the forces acting on the vertebrae and leads to axial back pain. Spinal fusion is designed to stop the relative movement of neighboring vertebrae by forming a dense bone bridge through the disk space and / or by creating a new bone formation in the posterolateral space in order to ensure stabilization, rigidity and strength. Sometimes spinal fusion involves the use of a bone graft taken from another point in the body (for example, an autograft from the iliac crest of the pelvis) or from an external source, i.e. allograft. Doctors often use the term "spinal fusion rate". Single-level fusion includes stabilization of two vertebral bones adjacent to the diseased disc. Two-level spinal fusion includes stabilization of three adjacent vertebral bones running along two problem spaces of the disc. Each vertebra is in contact (forms a joint) with neighboring vertebrae at three points - on paired arched joints located at the back, and on the intervertebral disk located in front. Thus, lumbar fusion can be directed to the posterior arched joints, or to the anterior interbody / disk space, or to both elements. If anterior interbody fusion is performed in combination with posterior fusion, the procedure is called 360-degree fusion. One of the widely used methods of posterolateral fusion is spinal fusion with a transpedicular screw, in which the screws are sent to the pedicular sections and bodies of neighboring vertebrae, and then the rods are connected to the screws in the disk space. Screws and rods hold adjacent vertebrae in a stationary state relative to each other and allow a bone graft placed either in the interbody (disk) space or in the posterolateral space to grow into a single bone. Known transpedicular screws and rods are made of metal, usually an alloy of titanium (Ti), but also previously made of stainless steel. Recently, rods are made of a polymer of minimal flexibility of polyetheretherketone.
Interbody fusion involves placing one or more spacers (usually pre-loaded with bone graft material) inside the interbody (disc) space between the bone bodies of the vertebrae after the degenerated disc has been cleaned and removed. The spacers are made of bone grafts, titanium, carbon fiber or polymers such as polyetheretherketone. Interbody fusion can be carried out on the basis of several approaches, including the anterior approach (anterior interbody fusion), the posterior approach (posterior interbody fusion or transforaminal interbody fusion) and the lateral approach (direct lateral interbody fusion, DLIF ™ - Medtronic, or extreme lateral spinal fusion, ™ - Nuvasive). The purpose of these approaches is to remove the degenerated disc and replace the disc with bone spondylodesis-causing material. In yet another embodiment, the disk may be replaced with an artificial joint / disk (described below). Each of these interbody approaches has its advantages and disadvantages. Anterior procedures require retroperitoneal dissection and carry the risk of damage to large blood vessels anterior to the spinal vertebrae. In addition, damage to the nerve plexus in front of the vertebrae can lead to sexual dysfunction. The lateral approach is promising, but limited to the upper and middle dorsal levels (rostral to L5, S1) due to an obstruction in the form of an iliac crest. The posterior interbody approach requires more time and usually more muscle dissection and retraction. However, the posterior approach allows you to place an interbody graft and perform posterior spinal fusion with a transpedicular screw and decompression of the nerves through one posterior incision (or incisions).
Although the anterior and lateral approaches can be performed independently (without posterior instruments), many surgeons duplicate or supplement the anterior or lateral interbody fusion by placing transpedicular screws in the back after the interbody cell or graft is placed. The specified 360-degree fusion limits movement to a greater extent than individual anterior or posterior fusion, increasing the rate of fusion. However, in the case of anterior interbody fusion and lateral interbody fusion (DLIF, XLIF), two groups of incisions are required for 360-degree fusion.
The posterior approaches (TLIF and PLIF) allow interbody fusion, transpedicular screw fusion, and neural decompression through the same posterior incision (or incisions). In the case of TLIF, one large interbody spacer is inserted from the side corresponding to the symptomatic side of the patient’s body after nerve decompression is completed. If both sides are symptomatic, decompression on both sides is required. The PLIF approach is accomplished by placing two interbody struts, one on each side. The posterior procedures can be performed as follows: (i) an open invasive procedure in which a large incision and / or several incisions are performed, (ii) a subcutaneous approach in which small incisions are made and / or a small number of incisions are performed, and theoretically (iii) an endoscopic approach, in which small incisions are made, and all instruments and devices are inserted through the mouth and visualization is provided on an external monitor.
As an alternative to fusion, recent discoveries in interbody stabilization have led to the development of artificial disc technology. Artificial discs replace degenerated discs and allow the movement of the joint. Both cervical and lumbar artificial discs have been developed. In addition, dynamic stabilization techniques have been developed for the back of the spine. For the implementation of these rear techniques, transpedicular screws and a dynamic shaft are used. Usually, a dynamic rod is equipped with a mechanism that allows it to bend under the influence of forces of a certain load, thereby absorbing a part of the pressure and tension applied to the spine. The advantage of dynamic stabilization is that mobility is maintained in the spine. However, there may be a problem with the wear resistance of these systems. In spinal fusion, a bone graft (interbody or posterolateral) fuses the vertebrae over time, eliminating the need for vertebral instruments (screws and rods). However, with dynamic stabilization, coalescence does not occur, and the screws and dynamic rods will be subjected to tension and forces acting on the spine all the time. Over time, the likelihood of loosening transpedicular screws or mechanical failure may increase. In some cases, the use of a small flexible rod, such as a rod made of polyetheretherketone, may ultimately enhance coalescence by lowering the insulation against pressure. Isolation from pressure occurs in rigid fusion structures that isolate the vertebral bone in contact with the bone graft from the pressures necessary for bone formation and correction.
Methods of posterior lumbar stabilization (spinal fusion and dynamic stabilization) have evolved over time into minimally invasive procedures, since such approaches with a minimum of exposure to surgical exposure reduce the likelihood of complications and accelerate the process of functional recovery of patients. Blood loss and hospital stay are reduced. The process of performing minimally invasive spinal fusion with a transpedicular screw is identical to the process of dynamic stabilization and includes two main stages. First, screws are inserted subcutaneously through the leg into the vertebral body. In minimally invasive systems, cannulated screws are inserted subcutaneously on a fluoroscopically (with x-ray image, which can be seen on the video screen) conducted wire. Usually two screws are used on each body of the fused vertebrae, one on the right side, the other on the left side. The second stage of the process involves connecting the screws to the rod and interlocking the rod and screws. In dynamic stabilization, the rod or rod-shaped device (flexible connector) is flexible, but the process of introducing said flexible rod is the same as in the case of fusion. For example, a rod-shaped device (flexible connector), like a rod, enters the screw heads, but may also include an element (shock absorber, spring, etc.), which allows movement to a certain extent. The differences between minimally invasive systems for the most part lie in the way the rod is positioned and the rod and screws interlocked through a minimum notch.
After inserting the screws and before inserting the spacer between the vertebral bodies, the damaged or degenerated disc in the disc space must be removed. With the TLIF approach, access to the disk space is through a facetectomy, in which the vertebral foramen around the nerve roots is opened with a bone-cutting tool, such as an ostiotome or high-speed drill. With the PLIF approach, a laminectomy or laminotomy is used to access disk space. Both TLIF and PLIF provide decompression of the tecal sac and nerve roots; however, a facetectomy in TLIF allows for maximum decompression of the escaping nerve root on the corresponding side. Thanks to the soft retraction of the tecal bag, access to the disk space is not difficult. You can then enter the tools used to clean out the degenerated disk into the disk space and complete the diskotomy.
After removing the disk, the surgeon must prepare the bone surfaces, called end plates, of the vertebral bodies on each side of the removed disk. Scraping the end plate with an instrument such as a curette causes bleeding, which stimulates healing and assimilation of the bone graft introduced into the interbody space. An inserted spacer or cell is typically made of bone, titanium, carbon fiber, or polymers such as polyether ether ketone. The spacer is typically hollow or at least porous to accommodate bone graft material. A bone fusion protein, such as a bone morphogenetic protein, is also often introduced into the spacer. After placement of the spacer and bone graft, the rods can be inserted into the transpedicular screws, and the screws can be tightened to secure the rods in place.
Typically, placement of subcutaneous screws is relatively straightforward. Insertion of the rod through the screw heads and mutual locking of the rod with the screws are the steps that are currently most difficult to achieve through a minimum incision. In most minimally invasive surgery systems in use today, the wire conductor is inserted subcutaneously under fluoroscopic control through the leg. Then expanding tubes and finally the tower are introduced through the wire in order to expand the fabric and to enable the screw to be inserted through the tower. Thus, the tower should be larger than the maximum diameter of the screw head. After the towers are placed at the desired point and the screws are inserted into each tower, a rod is introduced in one of various ways. The leading minimally invasive surgery system is Medtronic's Sextant ™. In this system, the rod is placed by forming a pendulum-like mechanism. Two or three towers (for one- and two-level fusion, respectively) are connected to each other to align the towers, and the rod swings through a separate incision above or below the towers like a pendulum. As soon as the rod has reached the desired point, locking caps are introduced and fixed through the towers. In another embodiment, in most other systems, the rod is inserted through one of the towers, and then the rod rotates about 90 ° in order to capture other screws in the other towers. Insertion of the rod through the screw heads in a minimally invasive system is carried out blindly, i.e. without direct visualization of the screw head. Because of this, the corresponding process is sometimes tiring and annoying.
The Sextant ™ system and other tower systems are limited by both the number of notches required and the size of each notch. Using a separate tower for each screw requires a separate cut for each screw. The Sextant ™ system also requires an additional incision for the shaft, and as a result, six incisions (one on each side) for single-level fusion and eight incisions for two-level fusion are necessary. Other tower systems that use the mechanism of direct insertion and rotation of the rod still require a single cut for each screw, and each cut should be larger than the size of the tower through which the screws are inserted. Typically, each notch is at least 15 mm long.
In US patent No. 7306603, entitled "Device and method for subcutaneous placement of lumbar transpedicular screws and connecting rods", Frank Boehm, ml. and others, and owned by Innovative Spinal Technologies (Mansfield, Mass.), disclosed a system for connecting a rod with transpedicular screws using a pin and recesses in the screw heads. According to this system, the rod can rotate around the longitudinal axis of the pin between the first position in which the rod is parallel to the longitudinal axis of the screw (i.e., oriented vertically) and the second position in which the rod is perpendicular to the axis in order to connect the screws on adjacent vertebrae. US Patent No. 7,306,603 includes various conductor systems (see FIGS. 5 and 6), rod holder systems (see FIGS. 8, 9, 10, and 11) and a rod conduction system (see FIG. 12), but does not include streamlined removable wire conductor system. The illustrated systems are tower-like with fairly large expanders (80 and 86 in FIGS. 6 and 8), stylet catheters (81 in FIG. 6) and / or an outer casing (120 in FIGS. 11 and 12).
U.S. Patent Application No. 20080140075, entitled "Pressed Pedicle Screw Assembly," by Michael Ensign, and owned by Alpinespine, LLC (American Fork, Utah), discloses attaching a rod to screw heads indirectly via a terminal apparatus. The terminal apparatus includes a casing, the inner diameter of which is smaller than the inner diameter of the screw head, so that the device is easily pressed into place on the screw head. Then the rod is placed by directly attaching it to the terminal apparatus after connecting the apparatus to the screw head. This application indicates the use of the Kirchner wire for inserting both transpedicular screws and the terminal element (see [0030], [0032], and [0045]), but does not disclose how the rods are guided to their location.
U.S. Patent Application No. 20080097457, entitled "Pedicle Screw Systems and Methods of Their Assembly / Installation," by David Warnick, does not belong to the company, and U.S. Patent Application No. 20080140075 also discloses the use of a terminal apparatus as an intervention to connect the rod to screws. In this system, instead of using a push-lock mechanism, the structure is clamped by rotating the inner element and the outer casing of the terminal apparatus relative to each other. In addition, as in U.S. Patent Application No. 20080140075, in U.S. Application No.20080097457, wire is only mentioned with respect to the use of K-wire to guide the insertion of transpedicular screws and the use of wire to guide rods is not disclosed.
US Pat. No. 7,179,261, entitled “Subcutaneous Access Devices and Bone Anchor Apparatus,” by Christopher Sivol et al., And owned by Depuy Spine, Inc., describes one of several tower systems for placing transpedicular screws subcutaneously. The patent describes a situation where the corners of the screws intersect, and the towers can interfere with each other. A similar situation is quite typical for lordosis of the lumbar spine, especially for the lumbosacral joint. In order to solve this problem, cuts in the tubes are described, due to which two tubes can intersect. Since the angles of the vertebrae vary depending on the patient, and the depth of the vertebra relative to the skin also varies significantly, many cutout options are needed. The present invention provides a maximum “cut-out” form where only the wire remains. Thus, interference in the form of several wires from neighboring vertebrae is not a problem. In addition, in the cut-out tubes described in US Pat. No. 7,179,261, screws or any other element introduced through the tubes must still be inserted through the tube at some point. Tubes with cutouts require that the screw (or other insertion element) be longitudinally oriented parallel to the long axis of the tube, since it is directed into the body until it reaches the cutout section, after which it can be rotated perpendicular to the long axis and directed to exit the lateral incision. In the present invention, through the use of a wire, an element inserted through it (i.e., a screw, a rod, etc.) does not need to be inserted through any cavity outside the body. In the present invention, when the screw is inserted by wire, the wire can simply be attached to the head of the screw. When the rod is inserted using the same wire, the wire can simply be fed through the outer edges of the rod body, attached with a retaining element or latch to the rod body, or between the outer edges of the rod body and the retaining element (holding thread). Thus, in the present invention, the inserted screws and rods can be oriented perpendicular to the long axis, or oriented in any other direction along the entire inlet path. This provides greater flexibility to avoid grazing of adjacent elements of the stabilization system and eliminates the need to identify areas with cuts by the surgeon before turning the screw / rod laterally and / or changing its orientation. USP '261 also does not disclose the use of cut-out tubes for accommodating spinal fixation elements such as rods. Only the use of tubes with cutouts for accommodating screws is disclosed (see 6: 9-61, 14: 9-31 and FIG. 2 with slots 60, 62). If the rods were inserted through the tubes and towers disclosed in USP '261, the rods would still have to be oriented parallel to the long axis of the tube (hypodermic access device) and initially inserted through the central cavity of the tube, as is the case with the rods, introduced through the tube without cuts. Tubes with cutouts are still tubes with a completely whole (not cut) circle at the proximal and distal ends, due to which the rod cannot pass across the entire tube transversely. The rod cannot pass through the tube if it is not oriented parallel to the long axis inside the cavity at some point, for example, at the initial entrance to the tube. In the traditional case with towers of transpedicular screws, the shaft must be precisely inserted through a small hole in each rigid tower. In the present invention, the wire can be controlled (straighten out or bent) in order to open the collection zone for the rod (see Fig. 13 and 14 of the present description). For the consideration of vertebral fixation and placement of elements in detail, USP '261 cites and includes by reference two related common patent applications. These methods of placing the rods are very different from the methods according to the present invention. In published application No. 20050131422 (US Patent Application No. 10 / 737,537), entitled "Methods and devices for placement of the vertebral fixation element", all procedures are performed through a single incision (see figure 10-11), and the rod must be inserted through the cavity tubes / towers at any point, but this point may be located outside the body. Inside the body, the second end of the rod should enter the lateral slot, and then you can rotate it perpendicular to the long axis of the route of administration. In published application No. 20050131421 (US patent application No. 10/738,130, in particular figure 10-16.) In the present invention, the same wire that is used to hold the screws can be used to accommodate the rods, thereby avoiding the step of introducing an additional device subcutaneous access. The present invention can be used to guide rods oriented perpendicular to the long axis of a conductive element (i.e., wire) at any point on the long axis.
The present invention is directed to improved minimally invasive (optionally adapted for use with the subcutaneous or endoscopic approach) TLIF and PLIF approaches, and to complement ALIF, DLIF and XLIF approaches. TLIF provides several benefits, including: (i) stabilization of both the front and back of the spine with a single back cut; (ii) the ability to fill a larger volume and various spaces with a bone graft material (anterior disk space with a spacer, between the screws and rods on the sides and in the back of the vertebra), which increases the chances of successful stabilization by developing and growing bone;
(iii) a spacer placed in the anterior disc space that maintains the natural height of the interbody disc in order to reduce pressure on the nerve roots (from bone spurs, thickenings, ligaments, etc .; and (iv) improved safety, since access to the spinal cord the canal is carried out only on one side, and this reduces the risk of pinching, stretching or other excitation of the vertebral nerves.The invention provides a Microfusion ™ product for minimally invasive posterior and / or transforaminal lumbar spinal fusion with a pedicle screw or stabilization procedures. References to "spinal fusion" below fully include stabilization, which provides somewhat more freedom of movement than complete bone fusion. Similarly, references to "spinal fusion" below fully include spinal fusion. The main cases when the surgeon can use the system Microfusion ™ is similar to Medtronic’s Sextant ™ system, and these include a minimally invasive TLIF procedure that includes: (i) micro-lumbar interbody fusion, MLIF ™, or (i i) a mini-open TLIF on the symptomatic side for decompression of neural compression, and spinal fusion with a pedicle screw through a minimally invasive incision on the opposite side. Similarly, the disclosed Microfusion ™ system is used bilaterally in the PLIF approach, and decompression and placement of the interbody strut are performed bilaterally. Alternatively, the Microfusion ™ system is ideal for “complementing” (with a rear cut of the minimum dimensions) the anterior interbody fusion (ALIF) and the lateral interbody fusion (XLIF ™ and DLIF ™). The entire MLIF ™ includes (i) transforaminal lumbar interbody fusion and stabilization, (ii) posterior lumbar interbody fusion and stabilization, (iii) anterior lumbar interbody fusion and stabilization, and (iv) lateral lumbar interbody fusion and minimization and stabilization micro "approach using a conductive system disclosed in the present description. Since lateral fusion is minimally invasive, a posterior incision of the smallest size for fusion of a pedicle with a pedicle is a very complementary element. Lateral interbody fusion is becoming more popular, and a growing number of companies specializing in the treatment of the spine are inventing their own lateral interbody fusion systems.
The lumbar spine has lordosis, in which the lower levels, L4, L5 and S1, are oriented posteriorly, and the middle levels, L2-L3, are oriented directly or anteriorly. The specified bend creates a unique situation in which the trajectories through the legs (the trajectories along which the pedicle screws are inserted) from L2 to S1 are not parallel. Instead, trajectories usually intersect at a point slightly posterior to the skin. The indicated configuration is similar to wheel spokes, where the spokes (trajectories) meet at one central point (hub). Since many patients have a similar lordotic configuration of the lumbar spine, it is possible to insert transpedicular screws through a single incision centered in the middle of the lumbar curve. However, if a separate tower (or tube) was required for each screw (as in traditional tower / tube systems) so that several screws could exist simultaneously, the total cross-sectional area of the towers / tubes would not allow the use of only one small incision. Towers / tubes interfere with each other and interfere with each other due to their size. An alternative method is needed to minimize the number and size of incisions. Reducing the number and size of incisions minimizes tissue damage required to accommodate transpedicular screws for lumbar stabilization or fusion. An ideal system or procedure could make full use of the natural curvature of the lumbar spine in order to achieve this reduction.
One object of the present invention is to provide an easy way to place two or more transpedicular screws using one small hole. This ensures the best cosmetic and functional result using just one cut on a small skin (about 1 to 2 cm in length), regardless of the number of screws used.
Another objective of the present invention is to provide the ability to insert, place and manipulate the rod and the locking mechanism through the same small incision in order to lock the rod inside the screws. The invention provides innovative methods for introducing the rod into the transpedicular screws, and methods for locking the rod inside the screws using one small incision. The method includes attaching one or more flexible but strong wires (or threads, ropes, cords, cables, etc.) to each head of the transpedicular screw, after which they are used to guide the rod to the screw. Since flexible wire is used, currently used with each tower / tube screw is not required. Screws, rods and locking mechanisms can be placed through one small incision and still remain correctly connected to each other due to the natural bending of the lumbar spine. By attaching at least one wire to each side of the screw head, two or more symmetrically balanced wires help precisely position the screw head. The wires also stop or limit the movement of the rod, forcing it to fit between the wires and enter directly into the screw head.
The wires can also be used to hold the locking mechanisms to the screw heads in the embodiments according to which the locking mechanism is not part of the screw head itself (and is not already located inside). In such embodiments, wire conducting is not required for the locking mechanism, since it is integrated in or is part of the screw head. Examples of the latter case include a hinged door above the shaft, which swings and latches in position, holding the shaft in place in the screw head. In this case, the built-in locking mechanism (on the screw head) is inserted into the foot simultaneously with the screw.
In a preferred embodiment, the locking mechanism is also carried out to the screw by means of small loops placed on the sides of the insertion tools. The wires pass through the indicated loops (loops pass over the wires) for holding tools for insertion into the screws in order to place (i.e., discharge or detach) the rods and locking means. Due to the flexibility of the wire and the fact that it has high strength, while maintaining a small diameter, several wires can simultaneously be even in a small notch.
An alternative embodiment is a hybrid system where each screw is placed through short towers that are not suitable for the skin surface. The wires are attached to the top of the towers, thanks to which the screw, rod, locking mechanism and tools used for insertion, adjustment, compression, drawing and removal are carried out by wires located close to the skin, but through separate towers located close to the bone and transpedicular screw. Said hybrid system provides both the advantages of wire, i.e. the ability of several wires to coexist in a single incision at the skin level, as well as the advantages of the tower system, preserved at the bone level. To some surgeons who find the tower system convenient but want to take advantage of the wire system, a hybrid system may seem most useful.
Another objective of the present invention is to reduce the discomfort of the patient and the risk of iatrogenic damage. Providing a system and method adapted for use with a single notch helps in solving this problem. It is necessary to make only one qualitative incision. With each incision performed, there is at least a small risk of accidental damage, including nerve damage, even if the incision is performed by an experienced surgeon. However, the incision is not the only dangerous stage of the procedure and is not the only stage that can cause injury to the patient, but is potentially ready for improvement in order to reduce this risk and deficiencies. Another stage of the procedure, often causing postoperative discomfort and reduced motor / sensory function in patients, is the placement of the rods inside the screws. The wire not only leads the rods to the screws, but also performs the function of holding nerves and muscles outside the screw head for easier insertion of the rods and locking mechanisms. If the nerves and muscles are prevented from entering the paths along which the rods are delivered, the risk of pinching, tearing, or complete rupture of the nerve or muscle is reduced.
Other objectives and advantages of the invention are noted in the following description. The alleged modifications of the present invention based on precise descriptions will at least partially be apparent from the description or may be noted by practice of the invention. Such minor, predictable modifications and adaptations should be within the scope of the present invention. Additional advantages of the invention can be realized and obtained using technical means and combinations, especially noted below.
The accompanying drawings, which are part of and are part of this application, illustrate embodiments of the invention and, together with the general description given above and the detailed description of embodiments given below, serve to explain the principles of the invention.
Figure 1 illustrates a transpedicular screw with a conical shaft directed downward, a concave U-shaped screw head, and removable elongated conductive wires directed upward (one wire on each side of the head). Elongated conductive wires can be attached directly to the screw head (image on the left) or can be attached to two or more short wires on each side of the screw head. This configuration forms a wire cage that causes the screw head and the shaft to align relative to each other when the rod lowers into the base of the screw head.
Figure 2 illustrates the insertion of the head of the transpedicular screw into the pedicular part of the vertebra from the anatomically right side of the central plate.
Figure 3 illustrates two transpedicular screws in the final position on two adjacent vertebrae on one side of the spinal column, where the screw trunks are immersed in the vertebral bones and the U-shaped screw heads protrude from the surfaces of the arches. Also shown is a rod held downward (at an angle) to the screw heads, between each of two sets of wires, one for each screw.
Figure 4 illustrates the rod in the correct final position, fully inserted into the heads of the pedicle screws in neighboring vertebrae along one side with partial (half completed, the other side not yet stabilized) single-level stabilization. The locking mechanisms are not shown here, but can also be carried out by wire to the screw heads.
5 illustrates wires (for holding rods, locking mechanisms, etc.), separated from the pedicle screws along the anatomically right side of the spinal column, but with the screw-wire system still in place, on the anatomically left side of the spinal column, ready to accept and guide the rod to the transpedicular screws. Locking mechanisms not shown.
6 illustrates a second rod in a position inside the screw heads on the arches of the spinal column from the anatomically left side, where the removable wires of the screw head remain only on the anatomically left side.
7 illustrates a preferred embodiment, where the rod also has wires or threads (called rod retention threads) on each side between its longitudinal ends, forming a loop with the rod body for securing the rod along the wires of the screw head during placement.
Fig. 8 illustrates a rod with retention threads directed downward to two screw heads (one for each longitudinal end of the rod), along the conductive wires of the screw head (corresponding to each side of each head of the transpedicular screw) inserted through the rod retention loop on each side of the rod. The rod holding threads "capture" the conductive wires, so that the ends of the rod cannot be pushed out of the screw head.
9 illustrates a preferred embodiment in which two conductive wires are attached to the top of the screw head, one on each side. Three directions (from left to right) illustrate the process of lowering the rod into the screw head conducted by conductive wires (upper row), as well as the end position in which the rod is completely located inside the screw head (lower row).
Figure 10 illustrates a locking mechanism that is lowered to attach it to a screw head to secure the shaft within it. The tool used to lock the locking mechanism on the screw head can also be held with a conductive wire, but is not shown in this diagram.
11 illustrates another preferred embodiment, where the conductive wires are connected to flexible strands. The strands are then connected to the top of the screw shaft or the base of the screw head. When the rod is lowered into the screw head by conductive wires, flexible strands are wrapped around the rod. Each strand has a length (approximately half the circumference of the rod), just enough to wrap it around the rod so that the ends of the conductive wires meet above the rod.
FIG. 12 illustrates how threads, such as in FIG. 11, can be wrapped around a shaft and brought together to hold a cannulated locking mechanism (i.e., a cap), as well as other cannulated instruments (not shown) to the screw head.
13 illustrates the insertion of a longer rod through 4 groups of conductive wires attached to 4 transpedicular screws during three-level stabilization. The left image shows the conductive wires in a neutral, straight position. The middle and right images show the conductive wires of the two upper vertebrae (L3 and L4) in an expanded form, so that the rod can be easily drawn between the wires.
14 illustrates a preferred embodiment in which a tool is used to separate conductive wires deep beneath the surface of the skin. Due to this, the incision in the skin remains small. A T-shaped tool with a hinged T-section is attached to the conductive wires and slides partially downward towards the screw head. When the hinged T-section opens, the middle portion of the conductive wires is separated. The specified open window allows the rod to pass between the conductive wires, especially in cases where the rod and the pedicle screws are inserted through separate incisions, as shown in Fig. 13 and Fig. 15.
15 illustrates two preferred embodiments of introducing the rod through conductive wires that come from a different incision than the rod itself. In this case, the two lower levels (L5 and S1) come from a common cut, and the upper two levels (L3 and L4) come from separate cuts. The retention threads of the rod extend only along the lower half of the rod and cover only the conductive wires of the two lower vertebrae (L5 and S1). The upper end of the shaft is then pushed through the conductive wires of the two upper vertebrae (middle drawing).
Alternatively, a thread attached to the upper end of the shaft can be used to pull the shaft through the conductive wires of the two upper vertebrae. The specified thread can be inserted between each set of conductive wires using a large surgical needle inserted through one incision and stretched through the next incision between the conductive wires.
Fig. 16 illustrates a preferred embodiment of flange mountings that help the rod to find the correct orientation for best entry into the screw head. As shown in the drawing, each fastener is preferably convex towards the rod, due to which, when the rod approaches the screw head, the entrance to the screw head can take the rod oriented at a number of angles, and nevertheless introduce the rod gradually aligning the orientation of the shaft as it approaches the base of the screw head.
Fig.17 illustrates the sequence of lowering the rod into a mis-oriented screw head (or, in another embodiment, lowering a mis-oriented rod into a correctly oriented screw head) using flange fasteners, as in Fig.16. The biconvex nature of the flange mounts allows the shaft to rotate and adjust when lowering. Otherwise, without flange fasteners, in a situation with incorrect orientation, the rod would hit the edges of the screw head, and further lowering would be impossible. Flange mountings are shown here as removable elements on the screw head; however, another preferred embodiment includes a flange and convex rod conductor embedded in the tops of opposite sides of the U-shaped screw head (i.e., it may be an integral part of the innermost portion of the screw head).
Fig. 18 illustrates another preferred embodiment, where the wire is connected to a screw with breakable elongated tabs. Extra long tabs are used to help insert the shaft into the screw head if the screw heads are not oriented correctly. The elongated tabs are removed by breaking off after the shaft is fixed in place. A wire attached to the elongated foot helps guide the shaft and locking mechanism into the screw head. The wire is removed by removing the elongated foot. The elongated tabs are cone-shaped or triangular in shape and work similarly to the flange mounts in FIGS. 16 and 17, leading the rod to the base of the screw head that is not correctly oriented.
19 illustrates another preferred embodiment, where the wire is connected to a latch or device holding the screw head. A preferred embodiment of the latch or device consists of at least two parts that can be disconnected after the rod is fixed in place, whereby parts of the device can be removed by wire. The latch or device is attached to the screw prior to insertion into the bone. The latch or device has a shape that does not prevent the rod from being placed in the base of the screw head. Parts of the latch are held together by a thin strand cut or torn after the shaft is fixed in place. The latch or device is made of metal, polymer or plastic materials, so that no waste remains after removing the latch.
The invention includes at least a screw, a rod and a locking mechanism, wire-wound down to the arches of the vertebrae, and the rod is fixed to stabilize the vertebrae. The locking mechanism may be integrated into the screw head or be a separate element. The locking mechanism may be held to the screw before or after insertion of the rod, depending on the structure of the locking mechanism used to secure the rod. In some cases, the locking mechanism is already on the screw head prior to insertion of the rod, and in other cases, the rod is first inserted into the screw head and is followed by the locking mechanism.
A preferred embodiment of the system of the present invention is the use of one wire 103 on each side of the head of the screw 102, that is, there are two wires 103 on each barrel of the screw 101 for tightly gripping the rod 104 above the barrel of the screw 101 inside the head of the screw 102. This embodiment is believed to be , provides the greatest stability of the rod 104 with the smallest volume of stabilizing elements (thereby allowing an extremely small incision to be made without stress on it). The wire 103 may be attached to the head of the screw 102 using (i) the wire itself, (ii) an elongated portion of the wire made of a material identical to that of which the wire itself is made, (iii) a filamentary material thinner than the wire, (iv) short turret or (v) an intermediate element, including an elongated tab 112, a flexible sheet, a flange 110, or a mechanical device / latch 113, as described below, as well as other features. A single wire 103 may be attached to the screw head 102 at one point or at two or more points 111, as shown in FIG. 1 illustrates a first configuration in which a single conductive wire 103 is attached to a screw head 102 (left image), and a second configuration in which one or more shorter wires 111 are attached to a screw head 102 and also attached to a single elongated wire 103 by others end (image in the center and on the right). Several short wires 111, attached directly to the head of the screw 102, can provide greater stability for easier alignment. To implement this configuration with multiple wires 111, insertion tools having side loops (not shown) through which the conductive wire passes also have side loops for a larger area created by the unfolded configuration of several short wires 111 in the vicinity of the screw head 102. Thus, the side loop attached near the tip of the insertion tool will have the same width as the screw head to accommodate all the short wires at the screw head. Above the transition zone (from several wires 111 to a single wire 103), the insertion tool will have smaller side loops that allow only a single wire to pass.
In an alternative embodiment, a single wire 103 can be made on only one side of each screw 101/102 or screw head 102. This embodiment further reduces the amount of stabilizing elements (screw head wires) that must pass through a minimum notch, but also reduces stability the rod. When only one wire of the screw head 103 is used for each transpedicular screw 101/102, it is also recommended to use at least one retaining thread of the shaft 105 (see FIGS. 7 and 8, illustrating the holding thread of the shaft 105). The screw head wire 103 should be inserted through a loop made by the retaining thread of the rod 105 along the lateral side of the body of the rod 104.
In another alternative embodiment, instead of one or more wires 103, one or more upward non-circular trunks (not shown) attached to the side of the screw head 102 may be used. The unique shape of the barrel prevents rotation or rotation of insertion tools around the barrel (i.e., when lowering them to the screw head 102). Thus, any non-cylindrical barrel will be capable of holding tools having a corresponding non-cylindrical barrel holder attached to the tool. For example, a barrel having an oval, square, rectangle, triangle, cross, trapezoid, star, or any other shape other than a circle in cross section will be able to prevent the insertion tool from rotating around the trunk if the insertion tool is provided with an appropriate shape holder to which the barrel fits exactly. The single-barrel mechanism, which is more dense than the wire, is most likely more rigid than the wire. However, if the screw head 102 is multi-axis, some flexibility will be retained when moving the barrel in the notch.
Screws 101 and screw heads 102 themselves can also have any of several different vertical and horizontal cross sections, including both round and non-round, rectangular, square, hexagonal, etc. The screws 101 and screw heads 102 are preferably made of an alloy of titanium or stainless steel.
The rods 104 are preferably cylindrical, but in the alternative, they may have a non-circular cross section (triangular, square, hexagonal, etc.) provided that the base of the screw head 102 has a suitable shape for tight insertion of the rod. The rods 104 are preferably made of polyetheretherketone (PEEK), but can also be made of any other biocompatible minimally flexible polymer or metal.
In another alternative embodiment, there may be more than two wires 103 per transpedicular screw 101/102. Preferably, if more than two wires are used per screw, there is at least one wire on each side of the screw and more than one wire on at least one side . An equal number of wires on each side increases stability and prevents distortions. However, the anatomy of each patient is slightly different, and when curvature (ie, scoliosis) and / or other aggravating diseases are present, stability with the insertion of the rod 104 can best be achieved by asymmetrically extending the wires of the screw head 103 around the perimeter of the screw head 102. B in any case, the surgeon is most qualified to make a decision on the selection of the wires of the screw head 103 and the retaining thread of the rod 105 based on the individual requirements of a particular patient.
The wires 103 on any single screw 101/10 can be placed at various points on the periphery of the screw (and not just on the sides) to improve stability and control. The term “screw 101/102” is used to mean the entire screw, including the barrel of the screw 101 and the head of the screw 102. The wires may be evenly distributed and symmetrical around the periphery, or may be asymmetric and uneven. For example, the presence of four wires on the screw head (i.e., one screw on each edge: north / top, east / right, south / bottom, west / left) allows the screw head 102 to be oriented along the axis of the rod 104 when moving the rod through notch and into the first screw head. Limiting open areas around the perimeter of the screw head 102 by creating essentially a wire cage can also cause the rod 104 to rotate in the right direction (or cause the screw head to rotate to accept the rod) when it moves from vertical longitudinal to lateral lateral orientation after placing the first end in the first screw head when the other end is guided for placement in the second screw head. The number of wires, their sizes (i.e. length and diameters), shapes, flexibility and strength can be changed based on the requirements of a particular procedure on a particular patient, based on the size of the notch to optimize the stability of the screw and facilitate alignment of the rod, while avoiding tangling the number of wires. Suggested embodiments include those with 1 to 10 wires per screw / screw head, especially those with 2 to 4 wires.
Instead of several long wires connected to the screw head 102 on each side, a single long wire 103 (or thread) is connected to several short wires 111, which in turn are connected to each side of the screw head. Thus, several wires 111 are still connected to each screw head 102, but these several wires are also connected to each other in a section above the screw head, forming a single wire 103 passing through the notch. The several wires 111 may still work to limit the movement of the rod 104 at least at the base of the screw head 102. The short wires 111 give the advantage of creating a wire cage that forces the rod 104 to enter the base of the screw head 102. A long single wire (or thread) 103 reduces confusion with a skin incision that occurs when there are a large number of wires. A few short wires 111 extending from the longitudinal axis of entry into approximately the same axis along which the rod 104 will eventually lie, also allows the long wire 103 and related tools to adjust the orientation and angle of the head of the screw 102 on this axis (the axis of the rod, approximately perpendicular to the longitudinal input axis used when inserting the bar). The screw head 102 is provided with a concave channel in which the rod 104 will be placed. The concave channel may be U-shaped in a vertical cross section, but any essentially concave shape suitable for holding the rod 104 and having dimensions corresponding to the dimensions of the rod 104 will be suitable . The upper edges of the screw head 102 itself or of the intermediate element 110/112/113 to which it is attached are capable of receiving an incoming rod in a wide range of angles and gently directing it to the correct angular configuration allowing entry into the screw base.
As an alternative to screws 101 or screw heads 102 attached directly to upwardly directed conductive wires 103 or conductive shafts, an intermediate flange, flange sheet, sheet 110, elongated tab 112, mechanical latch / device 113, or other element between the two can be formed. The screw 101/102 or screw head 102 at its outer edges can be turned into (as a unit) or attached to a separate element that is directly attached to the conductive wire / barrel 103, so that the screw 101/102 or screw head 102 and the conductive element 103 connected indirectly. The intermediate element is preferably adapted to move away from the screw 101/102 or the head of the screw 102 as desired, for example, after fixing the rod 104 in the correct position and locking it in place. Removal can be performed using a mechanical mechanism of breaking off / falling off, which can be activated by pressing a button on the proximal end of the surgeon's tool; by tearing along perforation; by cutting, turning, breaking off by swaying, annealing, heating, radial divergence, ultrasonic vibration, electrification / electric discharge, dissolution, loosening or any other method. In this case, where the conductive wires or upward trunks 103 are attached directly to the intermediate and easily removable element 110/112/113, the conductive wires 103 themselves can be more tightly attached to the intermediate element 110/112/113. For example, wires 103 may be soldered or welded to an elongated foot 112 that latches in / on and snapped off / from a groove or protrusion on the screw head 102. At least a portion of the elongated foot 112 may be threaded to fit screw 101/102 or a screw stem 101 having a corresponding thread, or to align a rod 104 having a corresponding thread.
The intermediate element can be made in the form of a sheet 110 of very thin material, which is flexible and can be stretched by stretching or tension. In the tensioned state, the sheet 110 is able to guide the rod 104 into the base of the screw head 102. Such a material may be rubber.
The intermediate element may be an inwardly tapering flange 110 attached to the inner upper edge of the screw head 102 and placed symmetrically around the base of the screw in which the rod 104 is located. Such a flange 110 is capable of allowing the incorrectly oriented rod 104 or screw head 102 to rotate and adjust relative to each other to a friend, when the rod is inserted into the base of the screw head, until the two elements are aligned to an acceptable degree. The tapering sides of the flange 110 may take the form of convex-curved wings 110, forming a channel for passing between the rod 104.
Alternatively, the intermediate element may be an elongated tab 112 with straight rather than convex sides. Preferably, the foot is triangular, which can be done by removing the corners of the initially rectangular foot. The wider base of the triangle can be attached to the head of the screw 102, as shown in Fig. 18.
The function of the screw head 102 or the intermediate element 110/112/113 is to form a channel into which the rod 104 can be easily held upwardly by the conductive wire 103 / conductive barrel. The screw head or the intermediate element is capable of taking a significant deviation in the orientation of the shaft and the base of the screw relative to each other and then guiding the shaft into the base of the screw until essentially perfect alignment is achieved. The advantage of this feature is that the system does not require starting anew, pulling out and reinserting the rod, if it turns out that the initial placement is not ideal.
The wires, threads, and intermediate elements described herein may be attached to the screw or screw head from the outside, inside, or through the cannulated portion of the upstream barrel 101. Many attachment points are possible if they do not interfere with the ability of the barrel 101 to drill into the bow and the shaft 104 and the locking mechanism 106 enter the base of the screw head 102.
The wire, thread or upwardly directed barrel 103 may be attached to the downwardly directed shaft of the screw 101, the head of the screw 102 or an intermediate element (i.e., flange, sheet 110, elongated tab 112) with glue, welding, thread, seams, rope, mechanical latch 113 etc.
In embodiments where the mechanical latch 113 is used to connect the upwardly conducting element 103 to the head of the screw 102, the latch 113 preferably has 2 sheets connected under the head 102 or at least under the line along which the rod 104 is lowered so as not to interfere with the rod . After closing the locking mechanisms 106 to secure the shaft 104 in place inside the head of the screw 102, the latches 113 can be removed. Removing the latches 113 from the head of the screw 102 also removes the wires 103 attached to the latches 113. The latches 113 can be removed in any way possible in a limited space, including (but not limited to): (i) removing the connection (as when removing the elongated tabs 112 ), (ii) cutting the material holding together 2 sheets, (iii) snapping off or opening, and (iv) detaching the Velcro.
Alternatively, in some embodiments, the locking mechanism may be part of the latch 113, due to which the latch is not removed, but continues to hold the rod 104 (see Fig. 19). In such cases, only the conductive wires 103 are simply removed from the latch-locking combination mechanism.
Instead of a mechanical latch with moving parts, the intermediate element (between the screw head 102 and the wires 103) may simply be a metal or plastic device without moving parts, but a tightly gripping head 102. The intermediate metal or plastic device can be removed by methods including ( i) breaking the thin central part connecting the two halves of the device, or (ii) cutting the rope connecting the two parts of the device. If the locking mechanism 106 for the rod 104 is separate from the intermediate metal or plastic device, then the device can be removed together with the wires after the rod is placed. If the locking mechanism is integral with or depends on an intermediate metal / plastic device, then the device should remain in place after the wires 103/111 are separated from it.
In another embodiment, shown in FIG. 11, the wire 103 or an additional thread 107 located thereon may be attached to a portion inside the screw head 102, where the rod 104 will eventually be located, for example, at the base of the screw head and / or to the upper edge downward the barrel of the screw 101. For example, the wire 103 or its additional part 107 may be attached inside the cannulated portion of the cannulated screw. When using flexible wire or an additional thread 107, the wire / thread can be wrapped around the rod 104 when the rod is placed in the head of the screw 102. The wire / thread can then be pulled through the cannulated instruments and the cannulated locking mechanism 106 above the rod.
Optionally, color-coded wires 103 and / or screws 101 can be made to assist doctors, specialists, and medical personnel in identifying elements, performing the procedure, and monitoring progress during subsequent patient visits. Alternatively, another form of visual marking can be used, for example with specific materials and / or visible only under certain conditions, in order to distinguish between wires, screws and other elements (i.e. fluorescent markers, radioactive isotopes, radiopaque markers visible on x-rays, magnetic nanoparticles, etc.). Another alternative or additional way of marking can be tactile marking (different surface textures) or sound marking (tactile or sound) instead of or in addition to visual. The marking may correspond to the right and left sides of the body, the medial and lateral elements, the size of the wire / screw, the shape of the wire / screw, the flexibility of the wire and / or its strength, among other features. The indicated list of matches in the marking or labeling system is illustrative and incomplete. One preferred marking system provides markers or color coding for wires intended for the medial side of the bar and wires intended for the lateral side of the bar. This marking makes it easy to separate the wires 103 when the rod 104 is inserted. This marking also helps with the insertion of instruments and the locking mechanism 106 along the wires 103 of the medial side and the lateral side. Some elements (wires 103, screws 101, screw heads 102, rods 104, holding threads 105, locking mechanisms 106, etc.) with similar characteristics can be marked in groups, for example, all wires of the medial side can be red, and all lateral wires are green.
Any locking mechanism 106 may be used in the present invention. The exact implementation of the locking mechanism 106 is not important if it is able to hold the shaft 104 inside the head of the screw 102 for clear and long-term stabilization. Examples of locking mechanisms 106 that can be used include tightening nuts, pressure caps, quick-drying glue, small revolving gates or a latch door, a group of elements that can be inserted to seal around the periphery of the shaft, etc.
Since the rod connects two or more separate vertebrae, the rod can first be fixed in the appropriate position (locked or tightened) using the locking mechanism on the first vertebra, and then, sequentially, on the second vertebra. In some cases, after the rod is firmly attached to the screw of the first vertebra, the location of the vertebra can be adjusted by the surgeon by moving the vertebrae closer to each other or further apart before the rod is attached to the second vertebra. If only one side of the shaft is locked, the other side of the shaft can easily be brought to the desired position. For example, the rod may slide vertically forward or backward through the locking mechanism until the desired distance is reached over which the rod passes between the locking mechanisms.
Wire 103 may be attached to screw heads 102 by a variety of mechanisms. Holding threads 105 can be attached to the ends of the rods 104 using the same set of mechanisms. The simplest attachment mechanism is to weld or glue the wire / thread to the screw head / shaft. Solder or glue may be cut off or broken off later. Neither the lateral retaining filaments 105 on the rod 104, nor the upwardly directed conductive wires 103 on the screw 101/102 or on the head of the screw 102 are required after the rod 104 is tightly placed inside the head of the screw 102.
The holding threads 105 on the rod 104, which hold it close to the conductive wires 103 when held in place, are preferably made of a flexible material, including metal wire, nitinol, rubber, catgut, plastic, polymer and biodegradable material. The retaining thread 105 should be easily removed after the rod 104 is secured in the correct position at the base of the screw head 102 and locked.
Alternatively, the wire / thread can be twisted into a threaded connector on the side of the screw / rod head, whereby the wire / thread is unscrewed when the operation is completed.
Other embodiments include attaching the wire 103 / holding thread 105 with soluble catguts tied to the head of the screw 102 / rod 104 and to the end of the wire / holding thread with a small loop or grooves in the head of the screw / shaft. Suitable soluble catguts include biocompatible synthetic absorbable materials, for example those made primarily of polyglycolic acid and other proven compounds. Specific grades of materials include Vicryl ™ (from Ethicon), Biovek ™ (from Dynek), Visorb ™ (from CP Medical), Polysorb ™ (from Covidien's Syneture) and Dexon ™ (also from Covidien's Syneture). The materials can be adapted for degradation or absorption over a period of time that corresponds to sufficient internal healing to successfully maintain adhesion. For example, standard Vicryl ™ typically retains tensile strength for three to four weeks. The materials may also be saturated with drugs or biomolecules (i.e., triclosan) to accelerate the healing process and prevent infection. If the biodegradation period (i.e. bioabsorption, bioerosion, etc.) for the catgut is too long and there is no need for the catgut immediately after the procedure, the catgut can be immediately cut off or burnt at the end to separate the wire / retaining thread from the screw head / the rod.
Another variant of the mechanism of attaching the wire to the screw head and the retaining thread to the rod is fixing with a material that burns, breaks or dissolves under the influence of current (i.e., radio frequency current). This option allows you to easily break the connection by simply passing current through a wire or thread. Preferably, the wire / retaining thread breaks in response to current applied outside the skin. Alternatively, an insulated conductive wire may be used to apply current within the target and minimally invasive method. An insulated conductive wire allows current to flow directly from the outer end (outside the body) to the current-sensitive material at the inner end, next to the transpedicular screw.
In yet another preferred embodiment of the attachment, the selected material (i.e., elastic rope or elastic) is flexible and can be stretched by pulling or pulling. It is important to use a very thin material that can be flexible and stretchable at the same time. These dual properties allow the material to safely guide the bar and tools through a small incision, without tearing and adapting to a limited space. If the flexible stretchable rope / elastic material is not biodegradable, it will need to be cut / broken off / burned or tied off from the screw head and wire (or rod and retaining thread) at the end of the procedure.
Instead of using intermediate material to connect the wire to the screw head and / or to connect the retaining thread to the shaft, another possibility is to make the wire and / or retaining thread of the same materials from which the intermediate connectors described above are made. In this case, the wire itself or the retaining thread is cut off or burned at the end of the procedure.
The final result in all cases is a clean, successful spinal fusion with a transpedicular screw, similar to that performed with screws and rods in an open procedure, but with a smaller incision and fewer components.
The material by which the conductive rod of the wire is attached to the screw head may be the same as the material of which the wire itself is made, or other material. The wires themselves are preferably made of a biocompatible metal having strength and wear resistance. In a preferred embodiment, the wires are made of nitinol (an alloy of nickel and titanium).
The material by which the holding threads 105 of the rod 104 are attached to the ends of the rod may be the same as the material from which the holding threads themselves are made, or other material. The retaining threads themselves are preferably made of a biocompatible metal having strength and wear resistance. In a preferred embodiment, the holding threads are made of nitinol (an alloy of nickel and titanium). Alternatively, in another preferred embodiment, the holding threads of the rod are made of biodegradable threads, so that they do not need to be removed after placement. Another advantage of the thread is that it does not interfere with the shaft and the locking mechanism-cap 106, if it gets between the cap 106 and the threads of the screw head 102.
In addition to the wire conductors 103, the present invention also provides a special rod 104 with its own retaining threads 105, which can fit between the wires. By attaching a small loop or ring to the ends of the shaft, two threads can be threaded through loops with good tension along the sides of the shaft. In this case, the wires 103 will pass between the rod 104 and the thread 105 in order to prevent the rod from slipping out and around the uppermost or lower wires (see Figs. 7 and 8). The holding thread 105 may also be attached to the shaft by means other than the loops or rings at its ends. Holes or perforations may be made in the rod 104 to secure the threads therein. The core may have grooves at the ends for which the thread engages. Thread 105 can be glued near the ends of the shaft. The rod holding yarns 105 hold the rod 104 for passage through the wires 103 and eliminate the risk of internal displacement of the rod from the target point of the screw 102. The holding threads 105 also accelerate the placement of the rod 104 in the screws 102/101, reducing the overall duration of the procedure.
The holding thread may be in the form of a strip or a long sheet of material, rather than a conventional thread. The material of the holding thread should be flexible, durable and biocompatible.
The steps for placing transpedicular screws and rods in a “micro-open” approach are described below. First, using fluoroscopy or stereotactic orientation, a single small incision is made on the skin 1-4 centimeters to the side of the midline through which all transpedicular screws will be inserted. Then, using a subcutaneous approach with a Jamshedi / Kirchner (K-wire) wire, a Wilcet muscle separation approach or a tubular system, place transpedicular screws (see FIG. 2). The pedicle screw insertion has loop loops that hold the side wires of the pedicle screw in place. After each transpedicular screw is placed, the side wires are pulled away from the notch to free up space for the other screws and to avoid tangling. After all the screws are placed, the screw head rotator is introduced and held down to the screw heads along each pair of conductive wires to align the screw heads in preparation for accepting the rods (see the aligned screw heads in FIG. 3).
After the screw heads are aligned, the side wires are divided into the medial and lateral sides. Then the rod slides between the medial and lateral wires in the screw heads. Preferably, the shaft should be bent prior to insertion. Markers on conductive wires at a certain distance from the tip of the conductive wires can help the surgeon to bend the shaft according to natural bending. Conducting wires emerging from a single notch are similar to light beams focused by a convex lens. These rays of light converge at a certain point and then create a virtual mirror image on the other side of the focal point. The same principle can be used to create a mirror image of the bending of the rod to perform the bending of the rod so that it fits exactly into the screw heads (see FIGS. 4 and 15). After each end of the shaft is correctly positioned inside the screw head, locking nuts or covers are screwed onto the screw heads to hold the shaft in place. Alternatively, a wire-driven compressor is used to compress the transpedicular screws, and then, during compression, final fixing can be performed. The conductive wires of the screw heads are then removed by any method, including cutting, turning, breaking off by swaying, annealing, radial divergence, dissolution, loosening, etc. (see FIG. 5 and FIG. 6, left). When the screws and rods in all fused vertebrae on one side of the vertebral column are stabilized, their “mirror” equivalents should be placed along the back side of the same vertebrae using similar fluoroscopic localization and other imaging means (see Fig. 5 with one rod, when preparing to the second, and Fig.6 with two rods placed).
The present invention can be used for dynamic stabilization or fusion of the vertebrae, while at the same time allowing you to remove a defective intervertebral disc and insert a spacer in its place. The spacer may include bone graft material or material for bone fusion to facilitate healing. Exemplary materials for bone fusion include bone morphogenetic protein, tricalcium phosphate, hydroxyapatite, and collagen.
Various elements (wires, screws, screw heads, rods, holding threads, locking mechanisms, etc.) according to the present invention can be provided in various sizes, shapes, strength, flexibility and other physical characteristics that are most suitable for specific patients and specific use cases.
13 illustrates how three-level stabilization can be carried out downward by the wires on the first screw head, while the wires on the second and third screw heads are pulled outward or bent to open a collection zone into which the rod can easily enter. In the traditional case with towers of transpedicular screws, the shaft had to be precisely inserted through a small hole in each rigid tower. The present invention eliminates this complexity.
As shown in FIG. 14, a thin T-shaped tool 108/109 can be used to separate the wires 103. This action prevents them from tangling (or untangles them) and opens the space between them, so that the rod can freely pass through them to enter screw head. The horizontal handles 109 of the T-tool extend outward, perpendicular to the longitudinal axis of insertion 108. These handles 109 can be folded in parallel along the main longitudinal body during insertion and removal. They can also be located inside the main body and released from the inside by telescopic extension or a spring-like mechanism. The end of each horizontal handle may be in the form of a letter U, a letter V, or a rounded shape so that the wire 103 can be held inside it. If the ends are in the form of letters U or V, the T-shaped tool 108/109 can be easily separated from the wire 103 after expansion by folding the handles along the longitudinal axis of the insertion 108 or by folding inside the main body. If the ends are in the form of a closed loop and the wires 103 are fed through and captured by them, the loops must be able to open to release them (like latches for jewelry) after tool 108/109 has completed its work.
The present invention is not limited to the embodiments described above. Various changes and modifications can certainly be made without departing from the scope of the present invention.
Additional benefits and modifications will be apparent to those skilled in the art. Thus, the invention in its broad aspect is not limited to the specific details and exemplary embodiments shown and described herein. Accordingly, various modifications can be made without departing from the scope of the concept of the present invention defined in the attached claims and their equivalents.
1. System for bone stabilization, containing:
first screw with first screw head,
a second screw with a second screw head,
dorsal fastener made with the possibility of its retention in the first and second screw heads,
at least a first guide element extending from the first screw and configured to pass through a skin hole through which it is inserted; at least a second guide element extending from a second screw and configured to pass through a skin hole,
moreover, the first and second guide elements are made with the possibility of overlapping and the possibility, when overlapping, of the direction of the spinal fastening element to contact with the first and second screw heads at an angle allowed by the guide elements taking into account an angle that is not parallel to the longitudinal axis of both guide elements.
2. The system according to claim 1, in which the first and second screws, the dorsal fastener and the first and second guide elements are made with the possibility of their introduction through an identical percutaneous incision or minimally invasive skin incision, the size of which is less than the sum of the smallest cross-sectional dimensions of the first and second screws .
3. The system according to claim 1, in which the first and second screws are made to be inserted through an identical percutaneous incision or minimally invasive skin incision, the size of which is less than the sum of the smallest cross-sectional dimensions of the first and second screws, and the dorsal fastener is inserted through the skin incision, different from the cut for screws.
4. The system according to claim 1, in which the first guide element contains at least one wire connected to the first screw head, and the second guide element contains at least one wire connected to the second screw head.
5. The system according to claim 4, in which the first guide element comprises at least one wire part connected to each side of the first screw head, and the second guide element contains at least one wire part connected to each side of the second screw head.
6. The system according to claim 4, in which the wires are attached to the screw heads by means of elongated legs attached to the screw heads and made with the possibility of easy detachment from them.
7. The system according to claim 1, in which the first and second guide elements are attached respectively to the first and second screws by means of a mechanical latch or a holding device tightly holding the corresponding screw heads, the latch or holding device made with the possibility of removal together with the guide elements after contact of the dorsal fastener with the first and second screw heads.
8. The system according to claim 1, in which at least the first and second guide elements comprise a rigid tower.
9. The system of claim 8, in which the first and second guiding elements contain rigid towers.
10. The system according to claim 1, in which the first and second guide elements or one of them contains a short tower and at least one wire or barrel, and the short tower is made with the possibility of its location below the skin hole, and at least one wire or the trunk passes through the skin opening when the corresponding screw is inserted into the bone.
11. The system according to claim 1, in which the dorsal fastener is a rod containing a holding element for holding the rod, made with the possibility of its direction at least by means of guide elements to facilitate insertion of the rod to the first and second screw heads.
12. The system according to claim 11, in which the retaining element for holding the rod is a detachable wire attached to a part located near the end of the rod passing through the guide elements to raise, lower, advance, pull and rotate the back fastener to the position in screw heads.
13. The system of claim 12, wherein the lead thread or wire is gripped through a skin incision in the screw head or guide member and attached to the holding member to hold the rod after threading the lead thread or wire through the guide elements and / or screw heads by means of a screw threading device , such as a large surgical needle, introducing the leading thread through the guiding elements and providing the ability to attach the rod to the leading thread and pulling it into position in the screw heads cut the same incision, which placed screws.
14. The system according to claim 1, in which the first and second guide elements or one of them contains at least one long wire attached to short wires connected to the corresponding screw head.
15. The system according to claim 1, further comprising a locking mechanism configured to attach the spinal fastener to the first and second screw heads.
16. The system of clause 15, in which the locking mechanism is made as a whole with the first and second screw heads or as part of them.
17. The system according to claim 1, in which the guide elements are configured to intersect at the intersection and which further comprises measuring means for measuring the depths of each guide element below the intersection and reflection of the measured depths above the intersection to create a virtual reflected image of the relative positions of the screws for providing the possibility of bending along the length or contour of the dorsal fastening element or the possibility for the surgeon to select its length or contour with an accuracy of bending and zmera.
a screw head with a base defining a channel for receiving the spinal fastener,
at least one wire extending from the screw head and configured to guide the spinal fastener into the channel of the base of the screw head.
19. The screw of claim 18, comprising a first wire portion extending from one side of the screw head and a second wire portion extending from the other side of the screw head.
20. The screw according to claim 18, comprising a tower attached to the screw head, wherein at least one wire is attached to the tower.
21. The screw of claim 18, further comprising a locking mechanism configured to attach the spinal fastener in the channel.
RU2011113701/14A 2008-10-01 2009-09-30 System and method for spine stabilisation using wired pedicle screw RU2513155C2 (en)
RU2011113701A RU2011113701A (en) 2012-11-10
RU2513155C2 true RU2513155C2 (en) 2014-04-20