Method and apparatus for performing spinal fusion surgery

#This application relates to implants, instruments, and methods for performing surgical procedures on the spine, including one or more of creating an operative corridor to the spine, delivering implants to the spine, fusing one or more segments of the spine, and fixing one or more segments of the spine.

#Spinal discs serve to cushion and stabilize the spine in addition to distributing stress and damping cyclic loads. The discs may become damaged due to injury or age and symptoms of a damaged disc may include severe pain, numbness or muscle weakness. Fusion is one method of reducing the magnitude of the symptoms of damaged spinal discs, or for any pathology that would suggest direct spinal decompression as a treatment. The primary goals of fusion procedures are to provide stability between the vertebrae on either side of the damaged disc and to promote natural fusion of those adjacent vertebrae. One of the most common fusion techniques utilized is the transforaminal lumbar interbody fusion (TLIF) in which the intervertebral disc space is accessed and operated on through a posterolateral approach. Generally, the TLIF procedure is performed through an “open” approach requiring a large incision and the separation and/or cutting of muscle and tissue, resulting in long recovery times and post-operative pain related to the procedure. To reduce the drawbacks associated with open procedures, minimally invasive techniques that reduce incision size and muscle cutting are becoming more popular. However, working through the smaller exposures brings other challenges, for example, decreased visualization and decreased flexibility in manipulating surgical instruments, among others, and thus the skill, training, and experience required for performing minimally invasive TLIF procedures is significantly higher than for open surgeries. A need therefore exists for improvements relating to the performance of minimally invasive TLIF procedures. The instruments and methods described herein are directed to addressing these needs.

#The present application describes implants, instruments, and methods for performing surgical procedures on the spine, including one or more of creating an operative corridor to the spine, delivering implants to the spine, fusing one or more segments of the spine, and fixing one or more segments of the spine.

#Many advantages of the present invention will be apparent to those skilled in the art with a reading of this specification in conjunction with the attached drawings, wherein like reference numerals are applied to like elements and wherein:

#FIG. 1 is a perspective view of an example of a surgical fixation system according to one embodiment of the present invention;

#FIG. 2 is an exploded perspective view of the surgical fixation system of FIG. 1;

#Illustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure. The systems and methods for performing transforaminal lumbar interbody fusion disclosed herein boast a variety of inventive features and components that warrant patent protection, both individually and in combination.

#FIGS. 1-5 illustrate an example of a surgical fixation system 5 according to one embodiment of the present invention. The surgical fixation system 5 includes a variety of sub-components dimensioned to allow for retraction of a soft tissue in order to establish an operative corridor through a patient's skin to a surgical target site. By way of example only, the surgical target site referred to herein throughout is an intervertebral disc space situated between two adjacent vertebrae. Although particularly suited for use in lumbar spine fixation, it will be readily appreciated by those skilled in the art that the surgical fixation system of the present invention may be employed in any number of suitable orthopedic fixation approaches and procedures, including but not limited to anterior, posterior, lateral, anterolateral, posterolateral, cervical spine fixation, thoracic spine fixation, as well as any non-spine fixation application such as bone fracture treatment.

#By way of example only, the surgical fixation system 5 includes a tissue retraction assembly 10, a plurality of hoop shims 6, and a plurality of bone anchors 7. According to one broad aspect of the present invention, the tissue retraction system 10 includes retractor body 12, a first retractor blade 14, a second retractor blade 16, and a third retractor blade 18 (also referred to herein throughout as the medial blade 18). The retractor blades 14, 16, 18 may be provided in any size and shape suitable to establish and maintain an operative corridor to the surgical target site, however, certain benefits may be achieved utilizing one or more aspects of the various shaped retractor blades described, which features should be apparent from the discussion herein. The bone anchor 7 may be one of the type shown and described in U.S. patent application Ser. No. 12/820,136, filed Jun. 21, 2010 and entitled “Polyaxial Bone Screw Assembly,” the entire contents are hereby incorporated by reference into this disclosure as if set forth fully herein. The tissue retraction assembly 10 may be configured such that the retractor blades 14, 16, 18 may be advanced to the surgical target site individually (e.g. sequentially) or together (e.g. simultaneously). For example, for simultaneous advancement, two or more of the retractor blades 14, 16, 18 may be attached to the retractor body prior to advancement to a surgical target site. As will be explained by way of example in further detail below, the tissue retraction assembly 10 is particularly suitable for individual advancement of each blade 14, 16, 18 to a surgical target site. For instance, the first retractor blade 14 may be advanced through an incision and securely attached to a first bone segment within the surgical target site. The second retractor blade 16 may then be advanced through an incision and securely attached to a second bone segment within the surgical target site. Once the first and second retractor blades 14, 16 are secured to the first and second bone segments, the retractor blades 14, 16 may then be attached to the retractor body 12. Thereafter, the first and second retractor blades 14, 16 may be further moved by the retractor assembly to a second “open” position to establish and maintain a second operative corridor (or working channel). This operative corridor may be variable in size and approach angle to the surgical target site, providing the ability to establish numerous custom working channels. The medial retractor blade 18 may then be attached to the retractor body 12 and used as desired.