US20230046670A1 - Minimally Open Retraction Device - Google Patents

Abstract

A retractor having a pair of blades is disclosed. A ring having an opening is attached to one end of the blades. The blades define a channel therebetween. The blades may be pivotally coupled to the ring. The retractor may have at least two conditions. In a first condition, the retractor is insertable through an incision in a patient's skin to an operative site. In a second condition, the retractor may be manipulated for retracting tissue surrounding the operative site. Instruments, prostheses, or tissue may be inserted or removed through the channel of the retractor.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application is a continuation of U.S. patent application Ser. No. 16/662,820, filed Oct. 24, 2019, which is a continuation of U.S. patent application Ser. No. 15/609,277, filed May 31, 2017, now U.S. Pat. No. 10,485,529, which is a division of U.S. patent application Ser. No. 14/833,609, now U.S. Pat. No. 9,681,863, filed Aug. 24, 2015, which is a division of U.S. patent application Ser. No. 14/228,639, filed on Mar. 28, 2014, now U.S. Pat. No. 9,131,934, which is a division of U.S. patent application Ser. No. 11/799,576, filed on May 2, 2007, now U.S. Pat. No. 8,696,560, which claims priority to, and the benefits of, U.S. Provisional Patent Application Ser. No. 60/796,921 filed on May 2, 2006, the entire contents of each of these prior applications are incorporated herein by reference.
BACKGROUND1. Technical Field
• The present disclosure relates generally to orthopedic spine surgery and, in particular, to a minimally open retraction device and methods for its use in a minimally open surgical procedure.
2. Background of Related Art
• In recent years minimally open surgical approaches have been applied to orthopedic spine surgery and more recently to spine fusions involving one or more vertebral bodies. Unlike minimally invasive procedures such as arthroscopic knee surgery or gallbladder surgery where the affected area is contained within a small region of the body, spine surgery involving a fusion typically spans a considerably larger length or portion of the body. For this reason, the idea of performing a minimally open procedure on the spine has only recently been approached.
• Minimally open surgery offers significant advantages over conventional open surgery. At the onset, the skin incision and subsequent scar are significantly smaller. By using more than one small incision rather than one large incision the need for extensive tissue and muscle retraction is greatly reduced. This leads to significantly less post-operative pain, shorter hospital length-of-stay and a faster recovery overall.
• A truly minimally open spine procedure should constitute the smallest damage or disruption possible to the surrounding anatomy. While there may be more than one incision or one long incision, depending on the number of levels needing attention, it is the amount of muscle retraction and scraping that will result in less operative trauma for the patient. A minimally open procedure is also less expensive, reduces hospitalization time, causes less pain and scarring, reduces the incidence of complications, such as surgical site infections, and has an increased speed of recovery.
• A typical spine fusion in the lumbar region, whereby at least two vertebral bodies are rigidly connected using screws implanted into the vertebral body and a solid metal rod spanning the distance between said screws, is by its nature not very conducive to a minimally open approach. Furthermore, a spine fusion is typically supported by implanting one or more interbodies into the disc space either using an anterior or posterior approach. An anterior approach requires a separate incision whereby the surgeon accesses the patient's spine through the abdomen. One advantage is the interbody used in this procedure closely matches the footprint of the adjacent vertebral bodies. The disadvantage is that an anterior procedure is typically performed at a different time and requires its own incision and access.
• A posterior approach to interbody implantation can be achieved through the same incision as that of the pedicle screws. Implantation of a Posterior Lumbar Interbody Fusion (PLIF) device requires bilateral removal of the facet joint while implantation of a Transforaminal Lumbar Interbody Fusion (TLIF) device can be achieved unilaterally and may require removal of only one facet joint. The advantage of the TLIF is that only one device is implanted into the disc space whereas a PLIF requires two bilateral implants.
• While the implantation of pedicle screws can be achieved with relatively little site preparation, interbody implantation requires considerable work. Once the facet joint is removed, the surgeon can begin removing the disc. One or more instruments may be needed to access the site at any time as well as sufficient lighting and suction. To perform these tasks the surgeon needs a suitable opening or channel to work through.
• There has been considerable development of retractors and retractor systems for minimally invasive procedures, with most of the new technologies being based on traditional types of surgical retractors for open procedures, predominantly table-mounted devices of various designs. These prior art devices are large and bulky and frequently do not adapt well to a less invasive approach. Standard hand-held surgical retractors are well known in the prior art and can be modified to fit the contours of these smaller incisions, but they require manual manipulation to maintain their position. Typical retractors also are positioned into the soft tissue and levered back to hold the wound open, frequently requiring re-positioning if they dislodge, obstruct the view, or the access ways.
• Several minimally open or minimally invasive access devices currently exist to achieve the goal of a suitable working channel. Most are either mounted to the surgical table or held in place by the surgeon or an assistant. Table mounted retractors offer little by way of flexibility. Furthermore, they do not offer a relationship or positional guidance with respect to the patient.
• Handheld retractors offer greater flexibility but require an extra hand to maintain position. They also may or may not offer a fixed relationship to the patient but in either case can easily be knocked out of position. Furthermore, handheld retractors typically offer a very long and narrow fixed channel to work through making the procedure even more challenging. Finally, any of the above mentioned retractors typically require a form of dilation to obtain the initial opening. Circular or oblong dilators are well known in the art.
SUMMARY
• The present disclosure is directed towards retractors configured for use in minimally invasive procedures. In particular, embodiments of the present disclosure include retractors that are configurable for insertion through a minimal opening in the patient's skin and are reconfigurable for retracting tissue surrounding a selected operative site.
• According to one embodiment of the present disclosure, the minimally open retraction device includes first and second elongate members or blades. The blades are generally arcuate and define a generally funnel shaped channel that extends through the retractor. A ring member is attached to the distal ends of the blades. The ring member has an opening extending therethrough. The blades are repositionable between a closely approximated position and a spaced apart position. In the closely approximated position, the retractor is insertable and removable through the incision in the patient's skin. After the retractor is inserted into an operative site, the blades are manipulated by the practitioner to retract tissue surrounding the operative site. In addition, the ring member may include opposing rod portions for attaching the retractor to pedicle screws located in the operative site.
• According to another presently disclosed embodiment, the retractor includes first and second sections. Each section includes a ring portion attached to a distal end of an elongate member or blade. The blade has a generally arcuate configuration. A pair of rod portions extends outwards from opposing ends of the ring portion. The rod portions of one section include complementary structures for slidably engaging the corresponding rod portions of the other section such that the rod portions are slidable relative to each other. When assembled, the ring portions define an opening and the arcuate blades define a generally funnel shaped channel that is in communication with the opening. Since the rod portions are slidably coupled, the size and shape of the opening is variable. As in the previous embodiment, the retractor may be coupled to pedicle screws.
• In a further embodiment of the minimally open retraction device or retractor, the retractor includes a pair of elongate members or blades that are operatively coupled to a ring member. The ring member is located at the distal ends of the blades and has an opening therethrough. Each blade includes a hole near its distal end. The hole cooperates with a loop that is attached to the ring member such that each blade is pivotally coupled to the ring member. A pair of opposing rod portions is attached to the ring member. As such, the retractor blades can be repositioned into close approximation with each other that rotates the ring about an axis of the rod portions. In this state, the retractor has a minimal profile and may be inserted through a minimal incision or opening in the patient. Once inserted, the retractor is manipulated to a second state for retracting tissue surrounding the operative site. As in previous embodiments, the retractor may be attached to pedicle screws located in the operative site.
• In an alternative embodiment of the present disclosure, the minimally open retraction device or retractor includes an arcuate member having opposing rod portions extending from the ends of the arcuate member. One blade includes a hole that cooperates with a loop attached to the arcuate member. The other blade has an arcuately shaped cutout in its distal region and a pair of protrusions with bores. The bores are sized to cooperate with the rod portions such that the blade is rotatable about the rod portions. In addition, the arcuate cutout and the arcuate member define an opening in the retractor.
BRIEF DESCRIPTION OF DRAWINGS
• Embodiments of the presently disclosed minimally open retraction device are described herein with reference to the accompanying drawings, wherein:
• FIG.1A is a top view of a minimally open retraction device according to an embodiment of the present disclosure;
• FIG.1B is a front perspective view of the minimally open retraction device ofFIG.1A;
• FIG.1C is a front perspective view of the minimally open retraction device ofFIG.1A attached to a pair of pedicle screws;
• FIG.2A is a top view of a first section of a minimally open retraction device according to another embodiment of the present disclosure;
• FIG.2B is an enlarged bottom perspective view of a second section of the minimally open retraction device illustrating features of extension members;
• FIG.2C is a bottom perspective view of the two sections of the minimally open retraction device ofFIGS.2A and2B as assembled;
• FIG.3A is a side perspective view of a minimally open retraction device according to a further embodiment of the present disclosure in a first state;
• FIG.3B is a front view of the minimally open retraction device ofFIG.3A;
• FIG.3C is a top view of the minimally open retraction device ofFIG.3A shown in a second state;
• FIG.3D is a front perspective view of the minimally open retraction device ofFIG.3C;
• FIG.3E is a side perspective view of the minimally open retraction device ofFIG.3A attached to a pair of pedicle screws;
• FIG.4A is a side perspective view of a minimally open retraction device in a first state according to an alternate embodiment of present disclosure;
• FIG.4B is a side perspective view of the minimally open retraction device ofFIG.4A in a second state;
• FIG.4C is a top view of the minimally open retraction device ofFIG.4A;
• FIG.4D is a side perspective view of the minimally open retraction device ofFIG.4B attached to a pair of pedicle screws;
• FIG.4E is a top perspective view of an alternate embodiment of the minimally open retraction device ofFIG.4A;
• FIG.5A is a perspective view of a further embodiment of the presently disclosed minimally open retraction device;
• FIG.5B is a bottom perspective view of the minimally open retraction device ofFIG.5A shown in one configuration;
• FIG.5C is a bottom perspective view of the minimally open retraction device ofFIG.5A shown in a second configuration;
• FIG.6A is a top plan view of a minimally open retraction device according to a further embodiment of the present disclosure;
• FIG.6B is a side plan view of the minimally open retraction device ofFIG.6A;
• FIG.7A is a top perspective view of a minimally open retraction device according to an alternate embodiment of the present disclosure;
• FIG.7B is a bottom perspective view of the minimally open retraction device ofFIG.7A in an insertion condition;
• FIG.8 is a side perspective view of a temporary set screw; and
• FIG.9 is a top perspective view of the minimally open retraction device ofFIG.4E installed onto a pair of pedicle screws.
DETAILED DESCRIPTION OF THE EMBODIMENTS
• Embodiments of the presently disclosed minimally open retraction device will now be described in detail with reference to the drawing figures wherein like reference numerals identify similar or identical elements. In the drawings and in the description which follows, the term “proximal”, as is traditional, will refer to the end of the minimally open retraction device which is closest to the operator while the term “distal” will refer to the end of the device which is furthest from the operator.
• Referring now in detail toFIGS.1A-1C, in which like reference numerals identify similar or identical elements, a minimally open retraction device, in accordance with a first embodiment of the disclosure, is generally designated as100.
• As shown inFIGS.1A and1B, a minimally open retraction device, orretractor100 includes first and second elongate members orblades110,120. Each of theblades110,120 include aproximal end112,122 and adistal end114,124. In addition, eachblade110,120 is arcuately shaped and formed from a resilient polymeric material. The distal ends114,124 are attached to aring130 that includes anopening132 therethrough. On opposing portions of thering130 are rod portions orextension members140,150. Thering130 and therod portions140,150 are formed from polyethylene. Although therod portions140,150 are illustrated as having a cross shaped configuration, other geometric shapes are contemplated (e.g. circular, hexagonal, or rectangular). It is contemplated that the distal ends114,124 of theblades110,120 are integrally formed with thering130.
• It is further contemplated that other suitable biocompatible materials (e.g. polyethylene, polypropylene, polycarbonate, polyetheretherketone, stainless steel, or titanium) may be used. In instances where a metallic material is selected, the material has a thickness that allows eachblade110,120 to bend and retract tissue. It is also contemplated that the thickness of eachblade110,120 may vary along its length, thereby adjusting its rigidity and flexibility for a selected procedure.
• Thering member130 is formed from a material that is more rigid than the material selected to formblades110,120. By forming thering member130 from a more rigid material than theblades110,120, the geometry of theretractor100 and theopening132 are maintained during retraction of the surrounding tissue. In addition, each of theblades110,120 include a plurality oforifices50. Theorifices50 are adapted to cooperate with a conventional instrument such as a Gelpi retractor.
• Eachblade110,120 is generally arcuate such that when theblades110,120 are moved towards each other (i.e. approximated), theretractor100 defines a funnel shapedchannel160 therebetween. Thechannel160 is in communication with theopening132 of thering130. As such, thechannel160 permits access to the operative site and the introduction and/or removal of surgical instruments, tissue, or prosthetic devices from the operative site.
• In addition, as shown inFIG.1C, theretractor100 may be coupled to a pair of pedicle screws10. As is known in the art, the pedicle screws may be monoaxial or polyaxial. Eachpedicle screw10 includes ahead12 defining achannel14. Aset screw16 may be threaded into thehead12. Thepedicle screw10 also includes a threadedshank18 for engagement with a selected bone structure (e.g. a vertebral body). Each of therod portions140,150 is configured and adapted to fit within thechannel14 of thepedicle screw10. When arod portion140,150 is positioned within thechannel14, theset screw16 is tightened and secures therod portion140,150 relative to thepedicle screw10. Theset screw16 may be loosened so that the practitioner may adjust the positioning of therod portion140,150 relative to thepedicle screw10 and then re-tightened when therod portion140,150 is in a desired position. In addition, the structural rigidity of thering member130 maintains the distance between the pedicle screws10 during the surgical procedure.
• Theretractor100 is installed through an incision or opening created in the patient's skin using techniques and instruments that are known in the art. In one embodiment, theretractor100 is installed through a minimal incision or opening. Once the incision is made in a desired location and the pedicle screws10 are positioned in the selected bone structures, theretractor100 is inserted into the incision. Working subcutaneously, the practitioner manipulates theretractor100 into a desired position and maneuvers therod portions140,150 into thechannels14 of the respective pedicle screws10. Theretractor100 may then be moved along an axis defined between the pedicle screws10, thereby allowing the practitioner to finely adjust the location of theretractor100. Once theretractor100 is in the desired location, the practitioner tightens theset screws16 to secure the position of theretractor100. Additionally, one or both of theset screws16 may be loosened or loosely installed in their respective pedicle screws10, thereby allowing the practitioner to reposition the retractor without necessitating removal and reinstallation of theretractor100. Subsequent to any repositioning, the practitioner tightens theset screws16 to lock theretractor100 in position.
• Once theretractor100 is in the desired location, the practitioner manipulates theblades110,120 by bending them outwards to retract tissue at the operative site, thereby increasing the size of the access opening at the operative site. As such, theretractor100 may be inserted through a relatively small opening and expanded to enlarge the opening for subsequent surgical procedures. Instruments, tissue, and/or prosthetic devices may then be inserted or removed through theopening132. Thechannel160 and theopening132 provide a convenient access portal for the practitioner to perform surgical procedures at the operative site.
• Advantageously, the shape of the access opening created using the devices and methods disclosed herein is generally funnel shaped, with a narrower section disposed within the incision localized on the area of interest between the pedicle screws, the location of the ring at the base of the funnel being secured relative to the pedicle screws. The funnel shape defined by the retractor with the flexible blades spread apart provides increased access space at the proximal portion of the incision, thereby providing increased visibility and the ability to insert and remove additional instrumentation such as suction, irrigation or lighting without interfering with the surgeon's ability to operate in the operative area at or below the bottom of the funnel shaped device.
• In an alternate embodiment of the present disclosure, a minimally open retraction device is illustrated inFIGS.2A-2C. The minimally open retraction device, or retractor is generally designated as200 (FIG.2C).FIG.2A illustrates onesection200aof theretractor200 with the other section200bbeing substantially similar. Thesection200aincludes an elongate member orblade210 having aproximal end212 and adistal end214. Theblade210 is arcuately shaped and formed from a flexible polymeric material similar to the materials used inmanufacturing retractor100. Anarcuate ring230 is attached to the distal end of theretractor200. Thearcuate ring230 is formed fromring portions230a,230bthat are at the distal ends214,224 of theblades210,220 (FIG.2C). It is contemplated that the distal ends214,224 are integrally formed with thering portions230a,230b. At the ends of thering member230, a pair of opposingrod portions240,250 is attached. Thering member230 and therod portions240,250 combine to define a substantially hemispherical structure. In particular, therod portions240,250 are attached to opposing ends of thering member230 and extend outwards therefrom. Thering member230 is formed from a resilient polymeric material and may be stretched or compressed accordingly.
• Therod portions240,250 are generally hemispherical structures. Each of therod portions240,250 include aplanar surface244,254. As shown inFIGS.2B and2C, theplanar surface244 ofrod portion240 is separated from theplanar surface254 ofrod portion250 by approximately 180°. Further still, theplanar surface244 includes arib242 that extends above the surface ofplanar surface244. Theplanar surface254 includes achannel252 that is recessed below theplanar surface254. Therib242 and thechannel252 are complementary in that they are both configured and dimensioned for slidably engaging one another.
• As assembled, the retractor200 (FIG.2C) includes first andsecond sections200a,200b. Thesections200a,200bare coupled together such that theribs242 slidably engage thechannels252 as described hereinabove. This arrangement permits the practitioner to vary the size of theopening232 as will be described in detail hereinbelow. As in the previous embodiment, theblades210,220 are bendable in relation to thering230 such that theretractor200 retracts tissue surrounding the operative site.
• Similar to the previous embodiment, the operative site is prepared by forming an incision or an opening in the patient's skin using known techniques and equipment. The pedicle screws10 may be installed in the selected bone structures either before the incision is made or subsequent to its creation. Once the incision is created at the operative site, the practitioner installs theretractor200.
• In a first technique, the practitioner couples the first andsecond sections200a,200bas described above and inserts the assembledretractor200 into the incision. The assembledretractor200 may be positioned between the pedicle screws10 using the techniques discussed with regards toretractor100. As such, theretractor200 may be substituted for theretractor100 that is illustrated inFIG.1C. The slidable arrangement between the first andsecond sections200a,200bpermits the practitioner to vary the size and configuration of theopening232. After the assembledrod portions240,250 are positioned in theirrespective channels14 of the pedicle screws10, the practitioner may slide therespective rod portions240,250 relative to one another, thereby expanding or contracting (i.e. re-configuring) theopening232. Thus, theretractor200 is capable of being installed through an incision and joining adjacent pedicle screws10 without the necessity of sizing theretractor200 to the operative site prior to commencing the surgical procedure. As such, the increased flexibility of theretractor200 allows the practitioner to install the pedicle screws10 in desired locations, form the incision between the pedicle screws10, install theretractor200, and adjust the size of theopening232 for accommodating the distance between the pedicle screws10.
• As shown inFIG.2C, theretractor200 is in its default condition. In this condition, the effective length of theretractor200 is defined by the distance between the distal ends of therod portions240,250 of eithersection200a,200b. If the distance between the pedicle screws10 is greater than the distance between the end regions of therod portions240,250, the practitioner merely slides therod portions240,250 away from each other (i.e. away from a center of the opening232) and effectively increases the overall length of theretractor200 such that it may be attached to the pedicle screws10 and locked in position using the set screws16. Alternatively, if the distance between the pedicle screws10 is less than the distance between therod portions240,250, the practitioner may slide therod portions240,250 towards each other (i.e. towards a center of the opening232) and effectively reduce the overall length of theretractor200 prior to securing it to the pedicle screws10 using the set screws16. In addition, by altering the effective length of theretractor200, the configuration of theopening232 inring230 is also altered. When the effective length of theretractor200 is increased, thering portions230a,230bare stretched and define a generally elliptical opening having its long axis along a longitudinal axis of therod portions240,250. When the effective length of theretractor200 is decreased, thering portions230a,230bare compressed forming a generally elliptical opening with its short axis along the longitudinal axis of therod portions240,250.
• Referring now toFIGS.3A-3E, a further embodiment of the present disclosure is illustrated. The minimally open retraction device or retractor is generally designated as300. Theretractor300 includes first and second elongate members orblades310,320. Eachblade310,320 includes aproximal end312,322 and adistal end314,324. In addition, eachblade310,320 has a generally arcuate shape. Thering member330 is attached to the distal ends314,324 of theblades310,320. Thering member330 is a circular structure having anopening332 and a pair of outwardly extendingrod portions340,350. As in each of the previous embodiments, the ring member is formed from a material having greater rigidity (i.e. structural strength) that the material used to form each of theblades310,320. By using a more rigid material, thering member330 maintains its geometry during the surgical procedure and further maintains the distance between the pedicle screws10 as will be discussed hereinbelow in connection withFIG.3E.
• Each of therod portions340,350 have a generally cylindrical shape and are located in opposition to one another such that they are approximately 180° apart from each other on an outer surface of thering member330. Therod portions340,350 may also have different geometric configurations such as rectangular, hexagonal, or cross shaped. Theblades310,320 are pivotally coupled to thering member330 and are positioned such that the points of attachment are approximately 180° apart on thering member330. In one embodiment, the distal ends314,324 are pivotally coupled to thering member330 vialoops316,326. Theloops316,326 are fixedly attached to thering member330, while each of theblades310,320 are movable along theloops316,326 via ahole318,328 (FIG.3E) in each of theblades310,320. Thus, theblades310,320 are capable of retracting surrounding tissue once theretractor300 is positioned in a desired location by urging theblades310,320 away from each other and retracting the surrounding tissue. As in the previous embodiments, one or both of theblades310,320 may be manipulated to retract tissue.
• Theretractor300 is capable of being transitioned from a first condition (FIG.3A) to a second condition (FIG.3C). In the first condition, theretractor300 has a minimum profile, thereby facilitating its insertion into an operative site since theblades310,320 are in close approximation with each other and thering member330 is substantially parallel with at least one of the blades. By manipulating theblades310,320, the practitioner rotates thering member330 to a position that is substantially perpendicular to theblades310,320 (i.e. the second condition) when theretractor300 is located in the operative site, thereby defining the opening at the base of theretractor300 adjacent the pedicle screws10.
• Specifically referring toFIG.3E, theretractor300 is shown connected to a pair of pedicle screws10. The pedicle screws10 are attached to selected bone structures in the patient's body using techniques and instruments that are known in the art. Once the incision is made in a desired location and the pedicle screws10 are positioned in the selected bone structures, theretractor300 is inserted into the incision with theretractor300 initially in its first condition (i.e. a minimal profile). Working subcutaneously, the practitioner manipulates theretractor300 into a desired position and maneuvers therod portions340,350 into thechannels14 of the respective pedicle screws10. Theretractor300 may then be moved along an axis defined between the pedicle screws10 allowing the practitioner to finely adjust the location of theretractor300. Once theretractor300 is in the desired location, the practitioner tightens theset screws16 to secure the position of theretractor300. Alternatively, one or both of theset screws16 may be loosened or loosely installed in their respective pedicle screws10, thereby allowing the practitioner to reposition the retractor without necessitating removal and reinstallation of theretractor300. Subsequent to any repositioning, the practitioner tightens theset screws16 to lock theretractor300 in position.
• Once theretractor300 is in the desired location, the practitioner manipulates theretractor300 and spreads apart theretractor blades310,320, such that theretractor300 transitions from its first condition to its second, funnel-shaped condition, thereby allowing the practitioner access to the operative site and retracting tissue surrounding the operative site. In addition, the practitioner manipulates theblades310,320 by bending them outwards to retract tissue at the operative site, thereby increasing the size of the opening at the operative site. As such, theretractor300 may be inserted through a relatively small opening and expanded to enlarge the opening for subsequent surgical procedures. Instruments, tissue, and/or prosthetic devices may then be inserted or removed through theopening332. Thechannel360 and theopening332 provide a convenient access portal for the practitioner to perform surgical procedures at the operative site. In addition, since thering member330 is formed from a material that is more rigid than the material selected for theblades310,320, thering member330 maintains its geometric configuration during the retraction process. Additionally, since thering member330 resists deformation, it maintains the relative positions of the pedicle screws10 to each other during the retraction procedure.
• Another embodiment of the presently disclosed minimally open retraction device is illustrated inFIGS.4A-4D and is generally designated as400. The minimally open retraction device orretractor400 includes first and second elongate members orblades410,420. Eachblade410,420 includes aproximal end412,422 and adistal end414,424. In addition, eachblade410,420 has a generally arcuate shape. Thedistal end424 of theblade420 has an arcuately shapedcutout423. Anarcuate member430 is releasably and pivotably coupled to the distal ends414,424 of theblades410,420. Thearcuate member430 has a pair of outwardly extendingrod portions440,450. Each of therod portions440,450 has a generally cylindrical shape and is located in opposition to one another such that they are approximately 180° apart from each other on an outer surface of thearcuate member430. In particular, therod portions440,450 extend in opposing directions from ends of thearcuate member430.
• In this embodiment, oneblade410 is pivotally coupled to thering member430 via aloop416. Theloop416 is slidably attached to thering member430 and theblade410 is movable along thearcuate member430 by sliding theblade410 and theloop416. Thus, theblade410 is capable of retracting surrounding tissue once theretractor400 is positioned in a desired location by urging theblade410 away from the opposingblade420 and retracting the surrounding tissue. In addition, theblade410 may be repositioned relative to therod portions440,450 by sliding theblade410 and theloop416 along the arcuate path defined by thering member430. Theother blade420 has first andsecond protrusions426,428 depending therefrom. Each of theprotrusions426,428 has abore427,429 extending therethrough. Thebores427,429 are configured to cooperate with therod portions440,450 such that theprotrusions426,428 are rotatable about therod portions440,450. Accordingly, theblade420 is rotatable about therod portions440,450. When theblade420 is moved away from theblade410, thecutout423 and thearcuate member430 define acircular opening432 through theretractor400. Additionally, the arcuately shapedblades410,420 define a funnel shapedchannel460 when they are spaced apart from one another (FIG.4C) which is wider at the proximal portion of the incision and narrower adjacent the pedicle screws10. As in the previous embodiments, one or both of theblades410,420 may be manipulated to retract tissue. In addition, theretractor400 has at least a first condition and a second condition. In the first condition, theblades410,420 are in close approximation with each other and define a minimum profile (i.e. the first condition) for theretractor400. In the first condition, theretractor400 is adapted and configured for insertion into a relatively small opening or incision in the patient's skin. In the second condition, theretractor400 is configured and adapted for retracting tissue surrounding the operative site. Once theretractor400 is positioned in a selected location, the practitioner manipulates theblades410,420 away from each other and retracts the tissue surrounding the operative site. As theblade420 is manipulated, theprotrusions426,428 rotate relative to therod portions440,450 thereby increasing the size of theopening432. Retracting tissue using theretractor400 is substantially similar to retracting tissue with previous embodiments of the retractor. In addition, theretractor400 can be attached to a pair of pedicle screws in the same manner as theretractor300 as illustrated inFIG.4D. Thearcuate member430 is formed from a material that is more rigid than the material used to form theblades410,420 and has the attendant advantages discussed with respect to thering member330.
• A further embodiment of the retractor is illustrated inFIG.4E and is generally designated as500. Theretractor500 has substantially the same or similar components as theretractor400 with the differences being discussed in detail hereinafter. In this embodiment,blade520 has a proximal end512, an arcuate cut-out523, and a pair ofdistal end portions514a,514b. Aloop516 is attached to eachdistal end portion514a,51b. The loops are configured and adapted to encircle therod portions440,450 such that theblade520 is pivotable about therod portions440,450. The arcuate cut-out523 and thering member430 define anopening532. Theblades410,520 have a generally arcuate configuration and define a funnel shapedchannel560 therebetween when the instrument is in a second condition. As in the previous embodiments, theretractor500 can be manipulated between a first condition having a minimal profile for insertion into a minimal incision in the patient's skin and a second condition for retracting tissue and accessing the operative site. In the second condition, instruments, prosthetics, and/or tissue may be inserted or removed through thechannel560, which provides access to the operative site for the practitioner. Additionally, theblades410,520 include a plurality oforifices50.
• Referring now toFIGS.5A-5C, an alternate embodiment of the presently disclosed minimally invasive retraction device or retractor is illustrated and referenced as600. In this embodiment, theretractor600 is formed as an integrated unit similar to the retractor100 (FIG.1A). Theretractor600 includes elongate members orblades610,610 androd portions640,650. Each of theblades610,620 include a plurality oforifices50. Additionally, theblades610,620 include aproximal end612,622 anddistal end portions614,624. Thedistal end portions614 of theblade610 are spaced apart from one another and define an arcuate cut-out613. Similarly, thedistal end portions624 of theblade620 are spaced apart from one another and define an arcuate cut-out623. The arcuate cut-outs613,623 define anopening632 through theretractor600. Furthermore, each of thedistal end portions614,624 includes anotch634 that extends partially through the respectivedistal end portion614,624 and defines a flexion joint about which theblades610,620 may be bent that is best illustrated inFIGS.5B and5C. Astrut636 connects thedistal end portions614,624 to therod portions640,650.
• Theretractor600 is initially substantially planar (FIG.5A) and is manipulated by the practitioner such that theblades610,620 are moved towards each other with thenotches634 defining the point about which theblades610,620 bend. After theblades610,620 are bent (FIG.5B), theretractor600 is in a first condition and has a minimal profile, thereby allowing theretractor600 to be inserted into a minimal opening in the patient's skin. Once the retractor is positioned in a selected area of the patient's body, the practitioner can manipulate theretractor600 to place it in a second condition (FIG.5C) for retracting tissue surrounding the selected operative site. In the second condition, theblades610,620 define achannel660 therebetween. In particular, thechannel660 is in communication with theopening632 and permits access to the operative site for the introduction and/or removal of surgical instruments, tissue, or prosthetic devices from the operative site.
• Theretractor600 further includesrod portions640,650 for releasably coupling theretractor600 to a pair of pedicle screws using the same techniques previously discussed with respect to theretractor100.
• Theblades610,620 may be formed from suitable materials as previously discussed with regards to theblades110,120 of theretractor100. Thestruts636 are formed of a more rigid material than are theblades610,620. Using a more rigid material for thestruts636 provides the same benefits to theretractor600 as did thering member330 to theretractor300. Specifically, using a more rigid material for thestruts636 provides increased rigidity and stability of theretractor600 such that theretractor600 maintains its geometry during the retraction procedure and maintains theretractor600 in position relative to the installed pedicle screws. Consequently, the pedicle screws are also inhibited from movement away from their selected installation position. That is, the selected distance between the pedicle screws remains substantially constant throughout the surgical procedure.
• In a further embodiment of the present disclosure, the minimally open retraction device or retractor is illustrated inFIGS.6A-6B and referenced as700. Theretractor700 includes first andsecond blades710,720. Theblades710,720 includeproximal portions712,722 anddistal end portions714,724. Thedistal end portions714 of theblade710 are spaced apart from one another and define an arcuate cut-out713. Similarly, thedistal end portions724 of theblade720 are spaced apart from one another and define an arcuate cut-out723. Eachblade710,720 includes a pair offeet716,726 attached to the respectivedistal end portions714,724. Thefeet716,726 extend away from the arcuate cut-outs713,723 and are substantially orthogonal to a plane defined by therespective blades710,720. Eachfoot716,726 has ahole702 extending therethrough. Theholes702 may be circular, elliptical, or oblong. When theholes702 ofblade710 are aligned with theholes702 ofblade720, the arcuate cut-outs713,723 define anopening732 that permits access to the operative site similar to theopening632 discussed with respect to theretractor600. In this embodiment, theblades710,720 are formed from materials that were previously discussed with regards to theretractor100.
• Alternatively, as seen inFIGS.7A and7B, the minimally open retraction device or retractor may be formed as an integral unit that is referenced as800. Theretractor800 includesblades710,720 having respective proximal ends712,722. Theblades710,720 includedistal end portions714,724. Thedistal end portions714,724 are connected at their ends, thus theretractor800 is an integrated device. Thedistal end portions714 of theblade710 are spaced apart from one another and define an arcuate cut-out713. Similarly, thedistal end portions724 of theblade720 are spaced apart from one another and define an arcuate cut-out723. The arcuate cut-outs713,723 cooperatively define anopening832 that extends through theretractor800 and permits access through theretractor800 to the operative site similar to theopening632 ofretractor600. A pair offeet816 is attached to the region where thedistal end portions714,724 join together. Thefeet816 extend outwards from theopening832 and include ahole802. Theblades710,720 can be manipulated by the practitioner towards each other (FIG.7B) such that theretractor800 is in a first condition and ready to be inserted into a minimal incision in the patient's skin. Once theretractor800 is installed through the skin and into the operative site, theblades710,720 may be spread apart (i.e. a second condition) as previously discussed in detail hereinabove with respect to theretractor600.
• Referring now toFIGS.8 and9, in conjunction withFIG.4E, a method of using theretractor500 is disclosed. A method and supporting structures for using theretractor500 are disclosed in U.S. patent application Ser. No. 11/528,223, filed on Sep. 26, 2006, owned by the assignee of the present application, which published as U.S. Patent Application Publication No. 2007/0106123, the entire contents of which are hereby incorporated by reference. An example of atemporary set screw16ais illustrated inFIG.8. Thetemporary set screw16aincludesthreads18aat a distal end thereof. Thethreads18aare adapted to engage corresponding thread structures in thehead12 of the pedicle screw10 (FIG.1C). At the opposing end of thetemporary set screw16ais a head that is adapted to engage driving tools as are known in the art.
• Initially, the practitioner installs a pair of pedicle screws10 using known open or mini-open surgical techniques and instruments. Alternatively, percutaneous placement of the pedicle screws10 is contemplated by any suitable technique. In this regard, the methods and devices of the aforementioned U.S. patent application Ser. No. 11/528,223 may be particularly useful if the pedicle screws10 are installed percutaneously in the selected locations, with an incision made through the patient's skin such that the incision spans the distance between the pedicle screws. The practitioner then dissects a minimum amount of tissue between the pedicle screws10 and installs anarcuate member430 therebetween. Thearcuate member430 includesrod portions440,450 that are received in thechannels14 of the pedicle screws10. Subsequently, a pair oftemporary set screws16ais installed into theheads12 of the pedicle screws10 and secure thearcuate member430 in its desired position. By securing thearcuate member430 to the pedicle screws10, the relative position of the pedicle screws10 to each other is maintained throughout the surgical procedure.
• Alternatively, the practitioner may substitute a different retractor forretractor500. For example, theretractor700 is installed by inserting one of theblades710,720 into the incision such that the shafts of thetemporary set screws16apass through theholes702. Once the first blade is installed, the remaining blade is installed in the same manner. With theblades710,720 installed in the operative site, the practitioner spreads theblades710,720 apart from one another and retracts tissue surrounding the operative site. The practitioner may grasp theblades710,720 and retract the tissue or may use a conventional retractor, such as aGelpi retractor850, to move theblades710,720. Alternately, the practitioner may select theretractor800 for the procedure. In this instance, the practitioner inserts theretractor800 into the incision and positions theretractor800 such that theholes802 are aligned with thetemporary set screws16a. Moving theretractor800 towards the pedicle screws10 couples theretractor800 to the pedicle screws10 by inserting the shafts of thetemporary set screws16athrough theholes802 of theretractor800. The practitioner then manually separates the blades810,820 of theretractor800 and retracts tissue surrounding the operative site. After the tissue is retracted, the practitioner may perform procedures on the accessible region such as a diskectomy, rod stabilization, prosthetic installation, etc.
• Additionally, the minimally invasive retraction structures disclosed in U.S. patent application Ser. No. 11/528,223 may be used in conjunction with eitherretractor700 orretractor800. In this configuration, incisions and openings are created in the patient's skin using known techniques. The pedicle screws10 are then installed in their desired locations. The pedicle screws10 may be installed prior to installing the minimally invasive retractors60 or they may be installed as an assembled unit. Once the minimally invasive retractors60 are installed over the pedicle screws10, the practitioner either manually separates the blades to retract tissue surrounding thepedicle screw10 or employs a conventional retractor (e.g. a Gelpi retractor) to separate the blades and retract tissue around thepedicle screw10. Once the tissue around the pedicle screws10 is retracted, the practitioner then makes an incision between the pedicle screws10 and dissects a minimally open region for inserting the arcuate member830. Once the arcuate member is positioned, the practitioner performs the steps previously discussed.
• Each of the presently disclosed embodiments provides a retractor that can be inserted through a minimal opening. In addition, the retractors are reconfigurable after installation such that the practitioners can retract tissue surrounding the operative site. The presently disclosed embodiments of the retractor also include orifices on the blades that are configured for cooperating with a convention retraction instrument such as a Gelpi retractor. Further still, the retractors provide an access opening for inserting or removing various instruments, prosthetics, or tissue. In conjunction with the above, pedicle screws may be installed and act as anchors points for the retractors and further increasing the options available to the practitioner during surgical procedures.
• In each of the disclosed embodiments, a funnel-shaped access opening is defined which is wider at the proximal, skin level of the incision and narrower at the bottom, or lower section of the incision where the retractor is fixed in position relative to the pedicle screws. Contrary to prior devices which attempt to create an access opening of the reverse shape, i.e., a narrower opening at the skin level and a widened section below the skin adjacent the working area on the facets and interbody space, the access opening of the present devices provides improved visibility of the operative site and the widened top section allows insertion and removal of instruments and accessories (e.g., light, suction, irrigation) without interfering with surgical instruments already inserted into the opening and which the surgeon desires to leave in place despite also desiring to introduce other accessories as mentioned above. The fixation of the lower portion of the retractor structure to the set screw is important, as the narrower end of the funnel-shaped retractor is maintained in the desired position relative to the anatomy to be operated upon.
• It will be understood that various modifications may be made to the embodiments of the presently disclosed minimally open retraction devices or retractors. Therefore, the above description should not be construed as limiting, but merely as exemplifications of embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the present disclosure.

Claims (20)

1. A system, comprising:

a first extension having a proximal end and a distal end, the first extension having a first attachment at the distal end; and

a first pedicle screw assembly including a first pedicle screw having a head and a shank,

wherein the first extension is coupleable to the first pedicle screw assembly by the first attachment such that the first attachment encircles at least a portion of the shank of the first pedicle screw.

2. The system ofclaim 1, wherein the first attachment creates a closed loop around the shank of the first pedicle screw.

3. The system ofclaim 1, wherein the first extension is a blade.

4. The system ofclaim 3, wherein the blade includes a plurality of holes spaced apart along a longitudinal axis of the blade.

5. The system ofclaim 3, wherein the blade is a flexible blade.

6. The system ofclaim 3, wherein the blade includes a living hinge.

7. The system ofclaim 1, further comprising a central longitudinal axis, wherein the first extension is on a first side of the central longitudinal axis.

8. The system ofclaim 1, wherein the first attachment includes an opening larger than the shank of the first pedicle screw and smaller than the head of the first pedicle screw.

9. The system ofclaim 8, wherein the first attachment further includes a relief region configured to allow the head of the first pedicle screw through the opening to separate the first extension from the first pedicle screw.

10. The system ofclaim 1, wherein the first attachment includes a concave surface adapted to mate with the head of the first pedicle screw.

11. The system ofclaim 1, wherein the first pedicle screw is a polyaxial screw.

12. The system ofclaim 1, further comprising a second pedicle screw assembly.

13. The system ofclaim 12, further comprising:

a second extension having a proximal end and a distal end, the second extension having a second attachment at the distal end; and

a second pedicle screw assembly including a second pedicle screw having a head and a shank,

wherein the second extension is coupleable to the second pedicle screw assembly by the second attachment such that the second attachment encircles at least a portion of the shank of the second pedicle screw.

14. The system ofclaim 13, wherein the second attachment creates a closed loop around the shank of the second pedicle screw.

15. The system ofclaim 13, further comprising an intermediate retractor blade.

16. The system ofclaim 15, wherein the intermediate retractor blade is configured to be coupled to the first and second pedicle screw assemblies via an intervening structure.

17. The system ofclaim 16, wherein

the intervening structure is shaped to be received within a first channel defined by the head of the first pedicle screw and a second channel defined by the head of the second pedicle screw.

18. The system ofclaim 17, wherein the intervening structure includes first and second rod portions shaped to be received within the respective first and second channels.

19. The system ofclaim 16, wherein the intervening structure includes a pair of feet each having an opening therethrough for receiving a portion of a respective one of the first or second pedicle screws.

20. The system ofclaim 19, wherein the respective one of the first or second pedicle screw portions are temporary set screws.

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