Search

EP-4424246-B1 - MULTI-SHIELD SPINAL ACCESS SYSTEM

EP4424246B1EP 4424246 B1EP4424246 B1EP 4424246B1EP-4424246-B1

Inventors

  • WANG, MICHAEL
  • WHITE, MICHAEL
  • THOMMEN, DANIEL
  • RICHTER, JOERN
  • ASSAKER, RICHARD
  • FESSLER, RICHARD
  • MEHREN, CHRISTOPH
  • TAN, SEANG BENG
  • TAYLOR, WILLIAM
  • BUEHLMANN, ERIC

Dates

Publication Date
20260513
Application Date
20180221

Claims (12)

  1. A system for accessing an intervertebral disc, comprising: a Mini-Flex-Arm and an access device for accessing an intervertebral disc, comprising: a) an outer shield (1) having a substantially tubular portion, a length adapted to extend from an incision to an articular process, a proximal end portion (3), a distal end portion (5), an outer surface (7), and a longitudinal throughbore (9) defining an inner surface (10), b) an inner shield (11) having i) a first substantially tubular portion (13) having a proximal end portion (15), a distal end portion (17), a longitudinal throughbore (19) defining an inner surface (21), and an outer surface (23) defining a diameter, and ii) a longitudinal flange (25) extending distally from the distal end portion (17) of the substantially tubular portion (13), wherein the outer surface (23) of the inner shield (11) substantially nests within the inner surface (10) of the outer shield (1) so that the flange (25) extends distally past the distal end portion (5) of the outer shield (1), wherein the outer shield (1) comprises a channel (557), wherein a depth adjustable endoscope system (561) is held in the channel (557), the endoscope system (561) consists of an endoscope and two tubes, one for irrigation (563) and the other one for suction (565), wherein the endoscope's channel (557) is parallel to the outer shield lumen, and wherein the channel (557) has a spring feature (559) capable of increasing the friction and therefore hold the endoscope in place, wherein the outer tube (1) comprises a non-detachable feature (555) capable for connecting with the Mini-Flex-Arm.
  2. The system of claim 1, wherein the outer surface (23) of the inner shield (11) substantially nests within the inner surface (10) of the outer shield (1) so that the distal end portion (17) of the substantially tubular portion (13) of the inner shield (11) extends distally past the distal end of the outer shield (1).
  3. The system of claim 1 or 2, wherein the proximal end portion (15) of the substantially tubular portion (13) of the inner shield (11) comprises a stop adapted to abut the proximal end portion of the outer shield, the stop (31) being adapted to prevent excessive distal movement of the inner shield (11), wherein preferably the stop (31) extends substantially radially about the proximal end portion (15) of the substantially tubular portion (13) of the inner shield (11), wherein more preferably the stop (31) further comprises a textured radial surface (33) adapted for gripping.
  4. The system of any of the preceding claims, wherein the flange (25) has an arcuate transverse cross-section, wherein preferably the arcuate transverse cross-section of the flange (25) defines an outer surface of the flange (25) having a curvature substantially similar to a curvature of the inner surface (10) of the outer shield (1).
  5. The system of any of the preceding claims, wherein the flange (25) defines a second substantially tubular portion (25) having a diameter less than the diameter of the first substantially tubular portion (13) of the inner shield (11), wherein preferably one of: the first and second substantially tubular portions (25) of the inner shield (11) are concentric or the first and second substantially tubular portions (15) of the inner shield (11) are not concentric.
  6. The system of any of the claims 1, 3 to 5, wherein the outer surface (23) of the inner shield (11) substantially nests within the inner surface (10) of the outer shield (1) so that the proximal end of the substantially tubular portion (13) of the inner shield (11) terminates within the outer shield (1), wherein preferably the distal end portion (5) of the outer shield (1) narrows distally to define a first radius, and the proximal end portion (15) of the inner shield (11) narrows distally to define a second radius, and the proximal end portion (15) of the inner shield (11) nests within the distal end portion (5) of the outer shield (1) to allow polyaxial pivoting of the inner shield (11).
  7. The system of any of the claims 1, 2, 4-6, wherein the inner shield (11) has a proximal elbow (51) that functions as a stop.
  8. The system of any of the preceding claims wherein the inner shield (11) has a sharpened distal tip (53) that functions as an anchor.
  9. The system of any of the preceding claims, further comprising c) a positioning ring (55) positioned between the proximal ends of the shields (1, 11), wherein the ring (55) is adapted to proximally fix the inner shield (11) upon the outer shield (1).
  10. The system of any of the preceding claims, wherein the inner shield (11) and the outer shield (1) together form a depth adjustment means (57).
  11. The system of any of the preceding claims, wherein the inner shield (11) further comprises a distally-extending rotating flange (71).
  12. The system of any of the claims 1 to 10, wherein the inner shield (11) further comprises distally-extending, rotating inner and outer flanges (81, 83).

Description

BACKGROUND OF THE INVENTION Today, microsurgical spinal bone resections and spinal decompressions which are performed under microscopic view through mini-open tubes and retractors are becoming the standard of spinal surgical care. These access tools normally have inner diameters between about 16 mm and 30 mm. Where, as here, the approach and decompression technique are familiar to spinal surgeons, and where standard equipment and instruments can be used, these known technologies should be considered as a base from which further innovation can be made. However, the anatomic window of Kambin's triangle, through which safe disc access is possible, has very limited dimensions. This access window can be enlarged by resecting at least a part of the superior articular process. But either way, the length of a working shield needed to safely introduce the implant to the intervertebral space via this approach must be in the region of about 8-12 mm in diameter, reaching from the facet joint line to the disc entry point. US 5 792 044 A teaches devices and methods for performing percutaneous spinal surgery under direct visualization and through a single cannula are shown. A device is provided which includes an elongated cannula having a first inner diameter and an outer diameter sized for percutaneous introduction into a patient. The cannula defines a working channel between its ends, which has a second diameter equal to the diameter of the cannula sized for receiving a tool therethrough. An elongated viewing element is engageable to the cannula adjacent the working channel. The fixture includes a housing attachable to the proximal end of the cannula that defines a working channel opening, which is in communication with the working channel. The housing also defines an optics bore adjacent the working channel opening. Methods are also provided for performing spinal surgeries percutaneously with direct visualization and without the requirement for a fluid-maintained workspace. SUMMARY OF THE INVENTION In accordance with the present invention, there is provided a system for accessing an intervertebral disc, which is defined in he appended claims. The present inventors envision introducing a second, inner shield through the above-mentioned first, outer shield. The second inner shield extends past the first outer shield to arrive next to nervous tissue, thereby shielding the nerves from instruments or devices passing through to the disc space. During this step, the outer shield allows the visual, safe placement of the inner shield. In one embodiment, there is provided an outer shield (which can be, for example, a tube or a blade) comprising an access shield with a larger diameter (~12-30 mm) that reaches from the skin down to the bone line, with an inner shield having a second smaller diameter (~5-12mm) extending past the access shield and reaches down to the disc level. This combines the benefits of the direct visual from microsurgical/mini open approaches and percutaneous techniques (FIGS. 1a-b and 2). The outer shield has a number of features and advantages. First, it enables separation and protection of surrounding of soft tissue and visualization during a standard microsurgical decompression/ bone resection work under microscopic view - based on a standard procedure that a surgeon who is familiar with MIS techniques is able to perform. Second, it enables separation and protection of surrounding of soft tissue and visualization during detection and removal of the facet joint, or parts of the facet joint - based on a standard procedure that a surgeon who is familiar with MIS technique is able to perform. Third, it enables identification, preparation and protection of sensitive (e.g., neural) tissue (exiting nerve root, traversing nerve root, dura) under direct visual control underneath the border between retraction-sensitive and non-retraction sensitive tissues (e.g., the facet line) - based on a standard procedure that a surgeon who is familiar with MIS technique is able to perform. Fourth, it enables insertion of the inner shield and potential docking of the inner shield in the disc space or at the vertebrae under direct visual control. Likewise, the inner shield has a number of features and advantages. First, it enables protection of nervous tissue (exiting nerve root, transverse nerve root, dura) against instruments that are introduced into the intervertebral disc. Second, it enables guidance of intradiscal instrumentation (discectomy instruments, visualization instruments, discectomy verification instruments, implant insertion instruments, bone graft filling instruments). Third, because of its small size, the shield can be inserted with minimal damage or trauma to bone and soft tissue in the area of the posterior column of the spine, comparable to percutaneous access instruments Further disclosed but not forming part of the claimed invention is a method of accessing an intervertebral disc in a patient, comprising the