US20230149007A1 - Retractor Blades For Modular Retractor System And Method Of Use - Google Patents

Abstract

A retractor system used in preparation for an oblique lateral interbody fusion surgical procedure includes a first retractor blade having a first proximal portion and a first distal end; a second retractor blade having a second proximal portion and a second distal end; and a connecting device that is configured to connect the first retractor blade to the second retractor blade. The first distal end of the first retractor blade is configured to engage a posterior portion of the vertebra and the second distal end of the second retractor blade is configured to engage an anterior portion of the vertebra. The length of the first retractor blade is less than approximately 96 percent of the length of the second retractor blade, and the first distal end of the first retractor blade extends at a non-zero angle from the first proximal portion of the first retractor blade.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application is a continuation of U.S. patent application Ser. No. 17/155,903, filed Jan. 22, 2021, entitled “Retractor Blades for Modular Retractor System and Method of Use,” and published Nov. 4, 2021 as U.S. Application Publ. No. 2021/0338220, which application claims the benefit of Provisional Patent Application No. 62/939,143, filed on Nov. 22, 2019, and titled “MODULAR RETRACTOR SYSTEM.” The entire disclosures of the applications above are incorporated herein by reference.
BACKGROUND
• Retractor systems may be used in a variety of different surgical procedures to provide an opening through which the doctor may access the surgical site. In spinal surgeries, for example, a retractor system may be used to provide the surgeon with access to the patient's spine. The opening created by the retractor system may, for example, enable the doctor to insert surgical instruments into the body or enable visualization of the surgical site using X-ray.
• Retractor systems may include a plurality of blades. In use, the blades may be inserted into an incision and then retracted to displace tissue surrounding the incision, thereby exposing the surgical site. To minimize trauma to the tissue, this tissue displacement should be refined and controlled. However, current retractor systems do not provide desired control of the distraction. More particularly, the devices currently in use limit the ability of the surgeon to feel the resistance at the blades as tissue is being retracted. The devices currently in use also limit the surgeon's ability to position and rotate the blades independently. This limited control takes away the skilled surgeon's ability to finely adjust the movement of the retractor blades.
• There is a need in the art for a system and method that addresses the shortcomings discussed above.
SUMMARY
• In one aspect, a retractor system used to retract tissue in preparation for an oblique lateral interbody fusion surgical procedure to fuse a vertebra to adjacent bony tissue includes a first retractor blade having a distal end with a flanged tip, a second retractor blade having a distal end with a cambered tip, and a connecting device that is configured to connect the first retractor blade to the second retractor blade. The flanged tip of the first retractor blade is configured to engage a posterior portion of the vertebra. The cambered tip portion of the second retractor blade is configured to engage an anterior portion of the vertebra.
• In another aspect, a retractor system used to retract tissue in preparation for an oblique lateral interbody fusion surgical procedure to fuse a vertebra to adjacent bony tissue includes a first retractor blade having a first blade portion with a first length, a second retractor blade having a second blade portion with a second length, and a connecting device that is configured to connect the first retractor blade to the second retractor blade. An end of the first retractor blade is configured to engage a posterior portion of the vertebra. An end of the second retractor blade is configured to engage an anterior portion of the vertebra. The first length is substantially less than the second length.
• In another aspect, a method of positioning a retractor system within a body in preparation for an oblique lateral interbody fusion surgical procedure to fuse a vertebra to adjacent bony tissue includes steps of inserting a first retractor blade having a flanged tip into an incision in the body, positioning the first retractor blade so that the flanged tip engages a posterior side of the vertebra, inserting a second retractor blade with a cambered tip into the incision in the body, positioning the second retractor blade so that the curved tip portion engages an anterior side of the vertebra, and securing the first retractor blade to the second retractor blade to fix their relative positions.
• Other systems, methods, features and advantages of the embodiments will be, or will become, apparent to one of ordinary skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description and this summary, be within the scope of the embodiments, and be protected by the following claims.
BRIEF DESCRIPTION OF THE DRAWINGS
• The embodiments can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, with emphasis instead being placed upon illustrating the principles of the embodiments. Moreover, in the figures, like reference numerals designate corresponding parts throughout the different views.
• FIG.1 is a schematic view of a modular retractor system in use during a surgical procedure, according to an embodiment;
• FIG.2 is a schematic view of a modular retractor system, according to an embodiment;
• FIG.3 is a schematic disassembled view of multiple components that comprise a modular retractor system, according to an embodiment;
• FIG.4 is a schematic view of a blade-to-blade articulating arm, according to an embodiment;
• FIG.5 is a schematic exploded view of a retractor blade, according to an embodiment;
• FIG.6 is a schematic cut-away view of a portion of a retractor blade, according to an embodiment;
• FIG.7 is a schematic view of a retractor blade assembly in an uncoupled configuration, according to an embodiment;
• FIG.8 is a schematic view of a retractor blade assembly in a coupled configuration, according to an embodiment;
• FIG.9 is a schematic view of two retractor blades inserted adjacent a segment of the spine, according to an embodiment;
• FIG.10 is a schematic view of an end of a table arm being coupled to a retractor blade, according to an embodiment;
• FIG.11 is a schematic view of fastening tool being used to couple an end of a table arm to a retractor blade, according to an embodiment;
• FIG.12 is a schematic perspective view of a connecting portion of a table arm being partially fastened to a retractor blade, according to an embodiment;
• FIGS.13-14 are schematic cross-sectional views of a connecting portion of a table arm being fastened to a retractor blade, according to an embodiment;
• FIGS.15-16 are schematic views of a retractor blade being temporarily fixed to bony tissue using a fixation pin, according to an embodiment;
• FIGS.17-21 are schematic views showing three retractor blades being coupled together using two blade-to-blade articulating arms, according to an embodiment;
• FIG.22 is a schematic view of three retractor blades aligned with a vertebrae to facilitate insertion of an implant, according to an embodiment; and
• FIGS.23-27 are schematic views of different retractor blade geometries, according to an embodiment.
DETAILED DESCRIPTION
• The embodiments described herein are directed to a modular retractor system and its method of use. The modular retractor system comprises a set of retractor blades that can be used to retract soft tissue and anatomical features in preparation for a surgical procedure. The blades can be independently inserted and positioned adjacent a surgical site and then coupled together using one or more blade-to-blade articulating arms. One or more blades can also be coupled to a fixed structure, such as a surgical table, using a table arm which locks the position of the blade in place relative to the fixed structure.
• Each retractor blade can be attached to a releasable handle. A surgeon can insert and manipulate the position of the retractor blade easily using the releasable handle. This enables the surgeon to receive important tactile feedback, reducing the chances of tissue damage caused by imprecise manipulation of the blades. Moreover, since each blade is positioned independently before it is fixed in place relative to the other blades, blade placement is not constrained to fixed spatial configurations, such as positions along a fixed ring or rectangle. Instead, each blade can be placed in an ideal location that is compatible with the particular patient's anatomy before the blades are securely fixed in place and locked to the operating table.
• Because the blade-to-blade articulating arms provide a rigid connection between the blades, this eliminates the need for more than one table arm in the surgical area and reduces the need for additional assistance in holding the blades in place.
• The embodiments describe a particular use of the modular retractor system in preparing an incision for oblique lateral interbody fusion (or OLIF) spinal surgery. OLIF is a less invasive approach to spinal fusion surgery in which the surgeon accesses and repairs the lower (lumbar) spine from the front and side of the body (passing in a trajectory about halfway between the middle of the stomach and the side of the body). During an OLIF procedure, the surgeon uses a corridor between the psoas muscle and the peritoneum to access the spine. The psoas muscles connect the lower back to the thighs and enable movement and flexibility of the back, pelvis, legs, and hips. The peritoneum is the membrane that lines the abdominal cavity.
• Although the embodiments describe a particular configuration of the retractor system for use with OLIF procedures, it may be appreciated that the retractor system could be used for retracting skin and other tissue during other types of suitable surgeries. Moreover, for use in other kinds of surgeries, in some cases, the linkages between the blades as well as the specific configuration of blades themselves could vary from the configurations described below.
• The terms “proximal” and “distal” may be used in the description. As used herein, proximal means closer a surgeon or person holding a component, while distal means further from the surgeon or person holding the component. Likewise, the terms “posterior” and “anterior” may be used in the description. A structure (part, portion, etc.) is anterior to another structure when it is closer to the front of the body. A structure that is posterior to another is closer to the back of the body.
• FIG.1 is a schematic view of a patient undergoing surgery. Specifically,patient101 is undergoing a spinal fusion procedure that uses the oblique lumbar interbody fusion (OLIF) approach. In this particular example, the patient is undergoing surgery at the L5-S1 spinal motion segment, also known as the lumbosacral joint. As shown in an enlarged focal view withinFIG.1, aretractor system100 is being used to retract soft tissue and anatomical features in preparation for the procedure. Also visible inFIG.1 is asegment150 of the spinal column, which includes portions of the lumbar spine and the sacral spine in the lower back. For purposes of illustration, a portion of thevascular system160 is also shown inFIG.1, as OLIF surgery typically requires mobilization of at least some portions of this system, such as the iliac and femoral arteries. For reference, the left common femoral artery is indicated inFIG.1 asartery162.
• FIG.2 is a schematic view ofretractor system100 shown in isolation. Additionally,FIG.3 shows a schematic top down view of the various components that may compriseretractor system100 in a disassembled configuration.
• Referring now toFIGS.2 and3,retractor system100 may include one or more retractor blades. In the illustrated embodiment,retractor system100 includes afirst retractor blade202, asecond retractor blade204, and athird retractor blade206. Together, the three retractor blades may be used to retract opposing sides of an incision, as well as to mobilize distinct portions of the anatomy, thereby creating an opening for an oblique lateral approach to the lumbar spine. As discussed in further detail below, the ends of each blade may be curved or otherwise shaped in a manner that assists in retraction of soft tissue and/or bone. For example, some retractor blades could be vein retractors, which tend to have flanged or curled ends that can be used to displace veins or other soft tissue. Other retractor blades could be Hohmann retractors, which may have a rounded tip that facilitates positive engagement with the bone.
• In the exemplary configuration, each of the three retractor blades may be utilized for a particular function in preparing the surgical site for an OLIF procedure. For example,first retractor blade202 may be designed for placement medially of the left common iliac vein, for a left sided up approach, or medially of the right common iliac vein/artery, for a right sided up approach.Second retractor blade204 may be designed for placement medially for the right common iliac vein/artery, for a left sided up approach, or medially of the left common iliac vein/artery for a right sided up approach.Third retractor blade206 may be designed for placement caudally of the bifurcation of the veins/arteries.
• Retractor system100 may be further comprised of components for attaching blades to one another in a manner that fixes the relative positions of the blades in a substantially rigid manner. In the illustrated embodiment, as shown inFIG.2,retractor system100 includes a first blade-to-blade articulating arm220 and a second blade-to-blade articulating arm222. As further shown inFIG.2, first blade-to-blade articulating arm220 is seen to connectfirst retractor blade202 withthird retractor blade206. Likewise, second blade-to-blade articulating arm222 is seen to connectsecond retractor blade204 withthird retractor blade206.
• To keep the retractor blades in an absolute fixed position, relative to the operating table, another articulating assembly may be used. For example, as seen inFIG.3, atable arm250 could be used. Unlike the blade-to-blade articulating arms,table arm250 may be used to connect a blade to a fixed structure in the operating area. Examples of fixed structures include, but are not limited to: operating tables, guide rails (on a bed or table), and/or any other structure in an operating area whose position is fixed during the procedure.
• Table arm250 may comprise an articulatingarm portion252 and aclamp portion254. Articulatingarm portion252 may further comprise abase segment260, a first articulatingsegment262, a second articulatingsegment264, and afastening segment266. When assembled, the free end ofsegment260 may be attached directly to clampportion254.
• First articulatingsegment262 may be coupled tobase segment260 by a ball-and-socket connector270, thereby allowing first articulatingsegment262 to articulate relative tobase segment260, as the position and orientation of the latter may be fixed relative to clampportion254. Second articulatingsegment264 may be coupled to first articulatingsegment262 by arotating connector272. As seen inFIG.3, rotatingconnector272 may include ahandle273 that can be used to tighten the connection and lock the rotational angle between the adjacent articulating segments.
• Fastening segment266 may be coupled to second articulatingsegment264 by another ball-and-socket connector274.Fastening segment266 may further include afastener276, which can be connected to corresponding fasteners on the retractor blades as discussed in more detail below.
• Referring again toFIG.1,table arm250 can be fixed at a first end to arail180 of an operating table viaclamp portion254.Clamp portion254 may be any type of mechanism suitable for removably securingtable arm250 torail180.Fastening segment266 can be fastened to a retractor blade (e.g., retractor blade202), thereby holding the blade in a fixed position relative torail180. The connection betweenfastening segment266 andretractor blade202 can be better seen inFIG.2. (For purposes of illustration, only a portion oftable arm250 is shown inFIG.2.)
• Although the exemplary embodiment shows a system comprised of three blades, in other embodiments only two blades could be used to retract an incision for a surgical procedure. In such an embodiment, the system may require only one blade-to-blade articulating arm to connect the two blades. Likewise, in still other surgical procedures, three or more blades could be used. When three or more blades are used, additional blade-to-blade articulating arms could be used to connect the additional blades to one of the first two blades.
• To facilitate positioning the retractor blades, the system may include a releasable handle for each blade. Once the retractor blade(s) are positioned, one or more of the releasable handles may be removed, e.g., via quick connect connections, from the blades in order to reduce clutter in the operating field.
• As seen inFIG.3, a retractor system can also include areleasable handle302. Releasable handle302 may be releasably attached to a retractor blade (such asfirst blade202,second blade204, or third blade206). Releasable handle302 may itself be further comprised of a graspingportion310 and aconnector portion312. In one embodiment,releasable handle302 may be a quick connect (QC) handle that utilizes a quick connection fastening system. Although a singlereleasable handle302 is shown inFIG.3, it may be appreciated that each blade may be configured with its own releasable handle.
• To assist in fastening the components of a retractor system to one another, a fastening tool such ashex driver320 could be used, as described in further detail below. For purposes of clarity a single hex driver is shown inFIG.3, however in other embodiments two or more different hex drivers may be used with a retractor system. In some embodiments, such a hex driver tool may be included with a kit of parts including all of the retractor components.
• FIG.4 is a schematic view of a blade-to-blade articulating arm400 (“assembly400”). Referring toFIG.4,assembly400 may comprise afirst segment402 and asecond segment404.First segment402 andsecond segment404 may overlap at corresponding inward ends (that is, ends located towards the center of the assembly). Moreover, these segments may be connected in a manner that facilitates rotation about acommon axis410. Arotating handle412 also rotates about the samecommon axis410 and allows the rotational angle between the segments to be locked into place when tightened.
• The outward ends of each segment include a blade-engaging connector that is pivotally connected to the segment by a ball-and-socket connector. Specifically,first segment402 is attached at its outward end to a first blade-engaging connector420 (“connector420”) by way of a first ball-and-socket connector430. Likewise,second segment404 is attached at its outward end to a second blade-engaging connector422 (“connector422”) by way of a second ball-and-socket connector432. To better illustrate the nature of the ball-and-socket connection, each blade-engaging connector is shown as exploded from its corresponding ball-and-socket connector. However, it may be appreciated that each blade-engaging connector may be fixedly attached to the male end of the associated ball-and-socket connector.
• Each blade-engaging connector is configured with a ring of teeth that can engage corresponding teeth on one or more blades. Specifically,first connector420 includes a ring ofteeth421, whilesecond connector422 includes a ring ofteeth423.
• Each blade-engaging connector is also associated with a threaded fastener. For example,first connector420 includes afirst opening440 that receives a first threadedfastener450. Likewise,second connector422 includes asecond opening442 that receives a second threadedfastener452. These threaded fasteners are used to secure the first and second blade-engaging connectors to the retractor blades, as described below and shown, for example, inFIGS.12-14.
• As seen inFIG.4, each offirst connector420 andsecond connector422 has an inward portion, an outward portion, and a curved intermediate portion. For example,second connector422 may include anoutward portion480, aninward portion482, and anintermediate portion484. The outward portion includes teeth for engaging a blade and the inward portion includes an opening to receive a projection from a corresponding ball-and-socket connector. The curved intermediate portion creates a step-down like geometry between the outward and inward portions. This configuration may provide sufficient clearance between the articulating arm and a connector on a retractor blade. Specifically, when the outward end of the connector is attached to a first connector on a retractor blade, the inward end may be displaced away from the blade by a sufficient vertical distance so that the inward end does not come into contact with a second connector on the blade, even as the arm is pivoted about the first connector prior to tightening the connection.
• FIG.5 is a schematic exploded view of an embodiment of aretractor blade500. In this embodiment,retractor blade500 may itself be comprised of ablade portion502, a mountingportion504, and areleasable connector portion506.
• Blade portion502 may be substantially straight along its length and may include afirst side590 and asecond side592. The first side may define a first direction that extends away from the first side and which is normal to the first side. The second side may define a second direction that extends away from the second side and which is normal to the second side.
• Mountingportion504 may be continuously formed withblade portion502, however mountingportion504 may have a different orientation fromblade portion502. For example, in the embodiment ofFIG.5, aplanar surface510 associated with the length and width ofblade portion502 may be disposed at an angle to aplanar surface512 associated with the length and width of mountingportion504. Here, mountingportion504 is seen to extend away fromsecond side590 ofblade portion502. Because the mounting portion is oriented along the direction of the handle, this orientation for mountingportion504 relative toblade portion502 allows a surgeon to better grasp and manipulate the retractor blade as it is inserted into the body.
• Mountingportion504 may comprise two fastener openings: afirst fastener opening530 and asecond fastener opening532. Each opening may overlap with a corresponding opening onreleasable connector portion506. Specifically,fastener opening530 may correspond to afastener opening540 inreleasable connector portion506, whilefastener opening532 may correspond to afastener opening542 inreleasable connector portion506. These openings may further receive a first threaded connector550 (throughfastener opening530 and fastener opening540) and a second threaded connector552 (throughfastener opening532 and fastener opening542). Each connector includes threading that can engaging corresponding threading in the openings ofreleasable connector portion506. When fastened into place, these connectors securereleasable connector portion506 to mountingportion504.
• Additionally, each connector includes a ring comprised of teeth. Specifically,first connector550 includes an outer ring560 that is comprised ofteeth562. Likewise,second connector552 includes anouter ring570 that is comprised ofteeth572. The teeth of each connector are configured to engage corresponding teeth in one or more of the articulating arms (such asteeth421 orteeth423 shown inFIG.4).
• As seen inFIG.5,releasable connector portion506 includes aquick connect end580 that is sized and shaped to mate with a corresponding opening in a quick connect handle (such ashandle302 ofFIG.3).
• FIG.6 is a schematic perspective cross-sectional view of a portion ofretractor blade500. Referring toFIG.6,retractor blade500 may include afirst surface602 and an opposingsecond surface604. When inserted into the body,second surface604 may be placed against soft tissue and/or bone in order to retract or pull at the tissue.First surface602 may face inwardly towards a cavity created inside the body by the use of two or more retractor blades. In some cases, the body ofretractor blade500 may be curved so thatfirst surface602 takes on a concave geometry, whilesecond surface604 takes on a convex geometry. The curvature ofretractor blade500 may help provide additional strength and support over a substantially flat blade. Additionally, when used in conjunction with other concave blades, the concavity of the blades provides an enlarged opening through which the surgery may be performed. Further, the convex geometry ofsecond surface604 may be more gentle to tissue being retracted.
• Alongfirst surface602,retractor blade500 may further include two slots for receiving fixation pins (such as Steinman pins), K wires, or other devices used for fixation. Specifically,retractor blade500 may include afirst slot620 adjacent one edge, and asecond slot622 adjacent the other edge.
• First surface602 can further include a T-shapedchannel630 that runs through the center of the blade along a lengthwise direction.Channel630 may accommodate an illumination device. For example, inFIG.7 anillumination device750 can be seen extending throughchannel630.Illumination device750 could be a strip-like device that provides illumination, allowing a surgeon to better visualize the area where the blade has been inserted. Using a channel inside the surface of the blade allows the illumination device to be integrated into the blade without the illumination device protruding from the blade's surface, possibly impacting adjacent tissue. In one embodiment, the illumination device comprises a sheath or segment of malleable aluminum, so that once inserted to the desired position withinchannel630, the proximal end of the illumination device may be bent back to help keep the device in place and out of the way of the surgeon.
• It may be appreciated that one or more blades in a retractor system could include slots for fixation devices (like pins) and/or channels for illumination devices. In the exemplary embodiment, bothfirst blade202 andthird blade206 are configured with these slots and channels, as seen inFIG.2.
• FIGS.7 and8 depict configurations ofretractor blade500 and a correspondingreleasable handle702, which are collectively referred to asblade assembly700. Specifically,FIG.7 showsretractor blade500 disconnected fromreleasable handle700, whileFIG.8 showsretractor blade500 connected toreleasable handle700. By using a quick connection between the blade and handle, a surgeon can easily remove the handle once the blade has been placed in the desired position, thereby helping clear the operative area of unnecessary components. This also reduces any chance that the handles may interfere with the placement of one or more articulating arms (either the blade-to-blade arms or the table arm).
• FIGS.9-21 depict schematic views of a procedure for assembling the retractor system at a surgical site in a manner that allows each blade to be individually inserted and positioned by a surgeon before the relative positions of the blades are fixed with respect to one another. For purposes of clarity, the exemplary procedure describes a process for inserting and assembling the retractor system in preparation for an OLIF surgical procedure. However, it may be appreciated that similar steps could be performed in preparing different parts of the body for other kinds of procedures. For purposes of illustration, only the components ofretractor system100 are shown, however it may be appreciated that the components are inserted, moved, and connected by a surgeon and/or surgical assistant(s).
• After an incision has been made and dissection to the spinal segment of interest (such as the L5-S1 segment) is completed, a surgeon may insertfirst retractor blade202 andsecond retractor blade204 into the incision area, as seen inFIG.9. In some cases, anillumination device910 may be used withfirst retractor blade202 to more easily identify the L5-S1 disc via direct visualization. As seen inFIG.9,first retractor blade202 is coupled toreleasable handle902, andsecond retractor blade204 is coupled toreleasable handle904. Using these handles facilitates easier blade manipulation for the surgeon.
• Upon insertion,second blade204 may be used to retract the medial aspect of the incision (not shown) andfirst blade202 may be used to retract the lateral aspect of the incision. Moreover,first blade202 may be placed on the medial or inner aspect of the left common femoral (artery920) artery to ensure there are no peritoneal contents between the blade and the L5-S1 disc.Second blade204, meanwhile, may be used to gently mobilize the prevertebral fascia over the L5-S1 disc space.
• With the two blades inserted,first blade202 can be provisionally attached totable arm250, which may have been previously clamped to a rail or other fixed structure. As seen inFIG.10,table arm250 can be attached tofirst blade202 by placingfastener276 over a corresponding connector onfirst blade202.
• As shown inFIG.9,first retractor blade202 can includefirst connector950 andsecond connector952.Fastener276 can be attached tofirst connector950 offirst retractor blade202 by eitherhand tightening fastener276 or by using a fastening tool. In the example shown inFIG.11,hex driver320 may be used to tightenfastener276.Hex driver320 may include an opening at its end that engages the hexagonal shaped body offastener276.
• FIGS.12-14 illustrate views of a connectingportion1220 oftable arm250 being fastened to a portion of aretractor blade1200. For purposes of illustration, connectingportion1220 is shown in isolation. InFIG.12, connectingportion1220 is aligned with aconnector1202 ofretractor blade1200, so thatfastener1230 can be inserted through a corresponding hole inconnector1202. Referring next to the cross-sectional views ofFIGS.13 and14, the threading1232 offastener1230 may engage corresponding threading1204 that is disposed in theinterior cavity1206 ofconnector1202. Rotatingfastener1230 by hand or using a tool drives the end of connectingportion1220 towardsconnector1202. As seen inFIG.14, when fully fastened,teeth1222 on connectingportion1220 may engageteeth1208 onconnector1202 to prevent any rotation between connectingportion1220 andconnector1202.
• It may be appreciated that this same connection mechanism can be used to connect the ends of any of blade-to-blade articulating arms with connectors on any of the retractor blades. In particular, each of the blade-to-blade articulating arms may be configured with similar connecting portions that can be fastened to connectors on the retractor blades.
• Referring now toFIGS.15 and16, withtable arm250 now secured tofirst retractor blade202,retractor blade202 can be further positioned if needed and then secured to the sacrum using a fixation device. In the exemplary embodiment, afixation pin1510 is inserted into a corresponding slot of thefirst retractor blade202. With the pin inserted,hex driver1504 can be placed over the head of the pin. Amallet1502 can be used to initiate insertion of the pin into the bone (FIG.15). Thehex driver1504 can then be used to fully insert thepin1510 intosacrum1520.
• FIG.16 showsretractor blade202 secured tosacrum1520 after bothfixation pin1510 andfixation pin1512 have been inserted into the bone using the above method.
• Afterfirst retractor blade202 has been secured tosacrum1520 using pins, any additional tightening of the connection betweenfirst retractor blade202 andtable arm250 can be done. Optionally, first releasable handle902 can be disconnected fromretractor blade202 and removed from the operating area, as shown inFIG.17, sincefirst retractor blade202 no longer needs to be manipulated during the procedure.
• Third retractor blade206 (withreleasable handle906 attached) can also be inserted at this time. In this example,third retractor blade206 is inserted at the bifurcation1704 of the artery. The surgeon can then manually adjust the position ofthird retractor blade206 as needed independently of the positions of bothfirst retractor blade202 andsecond retractor blade204.
• As shown inFIG.18,third retractor blade206, once positioned, can be secured tofirst retractor blade202 using first blade-to-blade articulating arm220. Specifically, afirst end1802 of first blade-to-blade articulating arm220 is fastened to second connector952 (seeFIG.17) offirst retractor blade202. Asecond end1804 of first blade-to-blade articulating arm220 is then fastened to a connector1702 (seeFIG.17) ofthird retractor blade206. These components may be fastened together in a similar manner to the fastening oftable arm250 tofirst retractor blade202, a depicted inFIGS.12-14. As seen inFIG.18, ahex driver1820 may be used to tighten the corresponding fasteners onassembly220.
• The dynamic range of motion that can be accomplished by blade-to-blade articulating arm220 by way of the ball-and-socket connections at its ends, and the twisting connection at its center, allows blade-to-blade articulating arm220 to adapt to any relative configuration offirst retractor blade202 andthird retractor blade206. Moreover,rotating handle1810 can be used to lock the two main segments of the assembly in place. Once attached to bothfirst retractor blade202 andthird retractor blade206, first articulatingarm220 may provide a rigid connection between the blades that locks their relative positions in place. At this point,releasable handle906 can be released fromthird retractor blade206, as indicated inFIG.19.
• FIG.20 illustrates the system once second blade-to-blade articulating arm222 has been used to fix the position ofsecond retractor blade204. Specifically, second blade-to-blade articulating arm222 has been secured tothird retractor blade206 at one end, and tosecond retractor blade204 at another. Once second blade-to-blade articulating arm222 has been fastened in place and tightened as needed, second releasable handle904 can be released fromsecond retractor blade204, as seen inFIG.21.
• In this final configuration, each retractor blade is fixed in place relative to one another. Specifically,third retractor blade206 has a fixed position relative tofirst retractor blade202 by way of first blade-to-blade articulating arm220. Likewise,second retractor blade204 has a fixed position relative to third retractor blade by way of second blade-to-blade articulating arm222. Andsecond retractor blade204 andfirst retractor blade202 have fixed relative positions by way of their mutual attachments tothird retractor blade206. Additionally, the attachment offirst retractor blade202 totable arm250 fixes the positions of the blades within the operating area.
• FIG.22 depicts a schematic view of the retractor system aligned with avertebra2202 along a transverse plane through the body. As seen inFIG.22, different blades may have different shaped distal ends (or tips) to perform different functions in preparing for an implant. For example,first retractor blade202 includes aflanged tip2210 at its distal end that facilitates both retraction of the incision and may help support and stabilizefirst retractor blade202 against a posterior portion ofvertebra2202 during and after the fixation of the blade tovertebra2202 using Steinman pins (as inFIG.16). In some embodiments, theflanged tip2210 may be bent at an approximately90 degree angle away from the rest offirst blade portion2230.Third retractor blade206 may also have a flanged tip (see, for example, the side view ofthird blade206 inFIG.3) to hold the bifurcation of the artery in place. By contrast, thesecond retractor blade204 has a slightly curved (or “cambered”)tip2212 at its distal end. This slight curvature ofend2212 helps the end ofsecond retractor blade204 to better accommodate the convex surface along ananterior portion2242 ofvertebra2202.
• As illustrated inFIG.22, the curvature offlanged tip2210 is substantially greater than the curvature ofcambered tip2212. For clarity, the radius of curvature of each tip is indicated within enlarged views ofFIG.22.Flanged tip2210 has a first radius ofcurvature2250 andcambered tip2212 has a second radius ofcurvature2252, which is substantially larger than first radius ofcurvature2250. This increased radius of curvature corresponds with a smaller relative curvature forcambered tip2212, as curvature is inverse to the radius of curvature.
• Not only is the degree of curvature different betweenflanged tip2210 andcambered tip2212, but the direction of curvature is also different.Flanged tip2210 bends towards a direction that is normal tosecond side2231 offirst blade portion2230. In other words,flanged tip2210 bends behind the first retractor blade as it faces towards a retracted opening in the body. This ensures thatflanged tip2210 can be used to retract and keep tissue away from the retracted opening.
• By contrast,cambered tip2212 bends towards a direction that is normal tofirst side2233 ofsecond blade portion2232. This creates a concave surface forcambered tip2212 along thefirst side2233 ofsecond blade portion2232. This concave surface is adapted to engage the convex surface ofanterior portion2242 ofvertebra2202.
• FIG.22 also illustrates the difference in length betweenfirst retractor blade202 andsecond retractor blade204. Here,first blade portion2232 ofsecond retractor blade204 is seen to be slightly longer than a correspondingsecond blade portion2230 offirst retractor blade204. The difference in length accommodates the different distances between the incision and different locations along the vertebra. In particular, the distance between the incision andposterior portion2240 ofvertebra2202 is slightly less than the distance between the incision andanterior portion2242 ofvertebra2202, due to the orientation of the body during the OLIF procedure. Thus,first retractor blade202 has a slightly shorter length than the length ofsecond retractor blade204, to accommodate these different distances and ensure the end of each retractor blade is able to engage the appropriate portion ofvertebra2202. For purposes of illustration, the different lengths forfirst retractor blade202 andsecond retractor blade204 are indicated inFIG.3, asfirst length290 andsecond length292, respectively.
• In one embodiment, a ratio between the first length and the second length may be in a range between approximately90 percent and approximately97 percent. That is,first blade portion2230 may be somewhere between 90 percent to 97 percent shorter thansecond blade portion2232. In one embodiment,first blade portion2230 has a length of140 mm, whilesecond blade portion2232 has a length of 150 mm. In another embodiment,first blade portion2230 has a length of approximately 170 mm, whilesecond blade portion2232 has a length of approximately 180 mm. In another embodiment,first blade portion2230 has a length of approximately 200 mm, whilesecond blade portion2232 has a length of approximately 210 mm.
• Once retraction is complete, discectomy and endplate preparation will be completed. Next, an implant specifically designed for the OLIF approach (approximately 25° off the coronal plane) will be implanted. When inserted using anapproach 25° off the coronal plane, the lordosis of the implant will be correctly aligned with the lordosis of the spine. InFIG.22, following retraction, animplant2204 has been successfully inserted betweenvertebra2202 and an adjacent vertebra or part of the sacrum.
• In some embodiments, each of the three blades that comprise the retractor system could have different geometries and/or dimensions. In one embodiment, for example,first retractor blade202 has the geometry ofretractor blade500 shown inFIG.5. The geometry ofthird retractor blade206 may be similar to that offirst retractor blade202 with some modifications. As an example, in some embodiments,third retractor blade206 may have the geometry of the blade shown inFIG.23. The geometry ofblade2302 may be similar in some respects toretractor blade500. In particular,retractor blade2302 may includesimilar channels2320 for receiving Steinman pins, as well as acentral channel2322 for receiving an illumination device. However, in some cases,retractor blade2302 may be substantially narrower thanretractor blade500. For example, in one embodiment,first retractor blade202 could have a width of approximately 30 mm, whilethird retractor blade206 could have a width of approximately 20 mm. This narrower width may helpthird retractor blade206 to better fit into the bifurcation of an artery.
• In some embodiments,second retractor blade204 may have a similar geometry toretractor blade2402 shown inFIG.24. As seen in comparingFIGS.23 and24,retractor blade2402 has a slightly different geometry toretractor blade2302. Specifically,retractor blade2402 lacks channels for receiving pins, though it does include acentral channel2404. Additionally, the rounded tip2406 may help engaging tissue for mobilization.
• Still other variations in blade design are possible. For example,FIGS.25 through27 illustrate schematic views of variations in the geometry of the blade ends. For example, some embodiments could include ablade2502 with a substantiallystraight end2504, as depicted inFIG.25. Some embodiments could include ablade2602 with abent end2604 having aconvex tip2606, as depicted inFIG.26. Other embodiments could include ablade2702 with abent end2704 having aconcave tip2706, as depicted inFIG.27. The type of blade tip geometry may be selected according to the type of tissue that must be retracted.
• As already discussed, the modular retraction system of the embodiments is configured to build a rigid frame outside of the body after the blades have been properly positioned by hand and pinned to a vertebral body.
• The present system gives the surgeon the flexibility to place the blades wherever they want without being limited by a rigid frame. This ensures that the blades are placed perfectly every time based on unique anatomic structures while still providing a rigid frame once the components of the system have been assembled and tightened. Placing the retractor blades by hand provides the surgeon with tactile feedback to help reduce the risk of vascular injury. Blade to blade fixation eliminates the need for someone (typically a physician assistant) to hold one of the blades in place during the procedure. If two blade to blade connections are used, this eliminates the need for a second table arm and removes clutter from the sterile field.
• While the exemplary embodiments describe using the modular retractor system to prepare for an OLIF approach at L5-S1 between the bifurcation, it can also be utilized for an OLIF approach at levels higher up in the lumbar spine. Furthermore, the retractor blades could be utilized for any surgical approach, spine or otherwise, that requires soft tissue retraction.
• It is contemplated that in some embodiments interchangeable parts of a modular retractor system could be prepared as kits that can be accessed prior to, or during, a surgical procedure. The kits could be prepared to include multiple retractor blades, releasable handles, blade-to-blade articulating arms, table arms, fixation pins, fastening tools such as hex drivers, and illumination devices.
• For each of the three retractor blades described above (e.g.,first retractor blade202,second retractor blade204, and third retractor blade206) a kit could be configured with interchangeable blades having different dimensions (for example, different lengths). As an example, a kit could include three different sizes associated withfirst retractor blade202. These could include a 140 mm length blade, a 170 mm length blade, and a 200 mm length blade. Additionally, a kit could include three different sizes of retractor blades associated withsecond retractor blade204. These could include a 150 mm length blade, a 180 mm length blade, and a 210 mm length blade. Furthermore, a kit could include three different sizes of retractor blades associated withthird retractor blade206. These could include a 140 mm length blade, a 170 mm length blade, and a 200 mm length blade.
• While various embodiments have been described, the description is intended to be exemplary, rather than limiting and it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible that are within the scope of the embodiments. Although many possible combinations of features are shown in the accompanying figures and discussed in this detailed description, many other combinations of the disclosed features are possible. Any feature of any embodiment may be used in combination with or substituted for any other feature or element in any other embodiment unless specifically restricted. Therefore, it will be understood that any of the features shown and/or discussed in the present disclosure may be implemented together in any suitable combination. Accordingly, the embodiments are not to be restricted except in light of the attached claims and their equivalents. Also, various modifications and changes may be made within the scope of the attached claims.

Claims (20)

What is claimed is:

1. A retractor system used to retract tissue in preparation for an oblique lateral interbody fusion surgical procedure to fuse a vertebra to adjacent bony tissue, comprising:

a first retractor blade having a first distal end;

a second retractor blade having a second distal end; and

a connecting device that is configured to connect the first retractor blade to the second retractor blade;

wherein the first distal end of the first retractor blade is configured to engage a posterior portion of the vertebra;

wherein the second distal end of the second retractor blade is configured to engage an anterior portion of the vertebra;

wherein the length of the first retractor blade is less than approximately96 percent of the length of the second retractor blade; and

wherein the first distal end of the first retractor blade extends at a non-zero angle from the rest of the first retractor blade.

2. The retractor system according toclaim 1, wherein:

the first retractor blade further comprises a blade portion and an attachment portion, the blade portion having a first side and a second side, the first side defining a first direction that is normal to the first side and extends away from the blade portion, and a second direction opposite the first direction; and

the attachment portion extends in the second direction away from the second side of the blade portion.

3. The retractor system according toclaim 2, wherein the first distal end of the first retractor blade curves towards the second direction.

4. The retractor system according toclaim 1, wherein:

the second retractor blade further comprises a blade portion and an attachment portion, the blade portion having a first side and a second side, the first side defining a first direction that is normal to the first side and extends away from the blade portion, and a second direction opposite the first direction;

the attachment portion extends in the second direction away from the second side of the blade portion; and

the second end of the second retractor blade curves towards the first direction.

5. The retractor system according toclaim 4, wherein the first side of the blade portion of the second retractor blade is concave.

6. The retractor system according toclaim 1, wherein the connecting device is an articulating arm.

7. The retractor system according toclaim 1, further including a third retractor blade that is longer than the first retractor blade and shorter than the second retractor blade.

8. The retractor system according toclaim 7, wherein the third retractor blade includes a third distal end that is substantially similar to the first distal end of the first retractor blade.

9. The retractor system according toclaim 1, wherein the first distal end of the first retractor blade has a flanged tip that extends at an approximately90 degree angle from the rest of the first retractor blade; and

wherein the second distal end of the second retractor blade has a cambered tip.

10. A retractor system used to retract tissue in preparation for an oblique lateral interbody fusion surgical procedure to fuse a vertebra to adjacent bony tissue, comprising:

a first retractor blade having a first blade portion with a first length;

a second retractor blade having a second blade portion with a second length;

a connecting device that is configured to connect the first retractor blade to the second retractor blade;

wherein an end of the first retractor blade is configured to engage a posterior portion of the vertebra;

wherein an end of the second retractor blade is configured to engage an anterior portion of the vertebra;

wherein the length of the first retractor blade is less than approximately96 percent of the length of the second retractor blade; and

wherein the end of the first retractor blade extends at a non-zero angle from the rest of the first retractor blade.

11. The retractor system according toclaim 10, wherein the first length is approximately 140 mm and wherein the second length is approximately 150 mm.

12. The retractor system according toclaim 10, wherein the first length is approximately 170 mm and wherein the second length is approximately 180 mm.

13. The retractor system according toclaim 10, wherein the first length is approximately 200 mm and wherein the second length is approximately 210 mm.

14. The retractor system according toclaim 10, wherein the connecting device is an articulating arm.

15. The retractor system according toclaim 10, wherein the end of the first retractor blade has a flanged tip that extends at an approximately 90 degree angle from the rest of the first retractor blade.

16. A method of positioning a retractor system within a body in preparation for an oblique lateral interbody fusion surgical procedure to fuse a vertebra to adjacent bony tissue, the method comprising the steps of:

inserting a first retractor blade having a first distal end into an incision in the body;

inserting a second retractor blade with a second distal end into the incision in the body;

retracting tissue proximate the incision by moving the first retractor blade and the second retractor blade away from one another;

positioning the first retractor blade so that the first distal end engages a posterior side of the vertebra;

positioning the second retractor blade so that the second distal end engages an anterior side of the vertebra; and

securing the first retractor blade to the second retractor blade to fix their relative positions.

17. The method according toclaim 16, wherein positioning the second retractor blade occurs after the first retractor blade has been positioned.

18. The method according toclaim 16, wherein securing the first retractor blade to the second retractor blade includes attaching a first end of an articulating arm to the first retractor blade and attaching a second end of the articulating arm to the second retractor blade.

19. The method according toclaim 16, wherein the method further includes attaching the end of a table arm to at least one of the first retractor blade or the second retractor blade.

20. The method according toclaim 16, wherein the second retractor blade is longer than the first retractor blade;

wherein the first distal end of the first retractor blade has a flanged tip that extends at an approximately90 degree angle from the rest of the first retractor blade; and

wherein the second distal end of the second retractor blade has a cambered tip.

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