Device for intraoperative navigation of the guide pin in percutaneous transpedicular fixation of the spine

Description

[0001] The utility model relates to the field of medicine, in particular to the field of neurosurgery and traumatology, and can be used to improve the accuracy of positioning the Kirschner wire, guiding cannulated instruments and screws during operations of percutaneous metal fixation of the spine under computed tomographic (CT) navigation. This reduces the risk of unplanned displacement of the wire and the development of perioperative vascular, neurological and other complications [Heini P, Schöll E, Wyler D, Eggli S: Fatal cardiac tamponade associated with posterior spinal instrumentation. A case report. Spine (Phila Pa 1976) 23:2226-2230, 1998; Mamane W, Breitel D, Lenoir T, Guigui P: [Spinal migration of a Kirschner wire after surgery for clavicular nonunion. A case report and review of the literature.] Chir Main 28:367–369, 2009 (Fr); Was MT, Kurowski K, Francuz I: Migration of Kirschner wire into the spinal canal as a complication of inveterate shoulder luxation treatment—a case study. Ortop Traumatol Rehabil 12:370–375, 2010; Gubin AV, Ryabykh SO, Burtsev AV. Retrospective analysis of screw malposition after instrumental correction of thoracic and lumbar spine deformities / / Spine Surgery. 2015. Vol. 12, No. 1. P. 8–13; Bredow J, Boese CK, Werner CM, Siewe J, Löhrer L, Zarghooni K, Eysel P, Scheyerer MJ. Predictive validity of preoperative CT scans and the risk of pedicle screw loosening in spinal surgery. Arch Orthop Trauma Surg. 2016 Aug; 136(8):1063-7. doi:10.1007 / s00402-016-2487-8. Epub 2016 Jun 16. PMID: 27312862].

[0002] The widespread adoption of intraoperative CT navigation in the last decade has significantly simplified the performance of percutaneous transpedicular fixation (TPF) of the spine [Gelalis ID, Paschos NK, Pakos EE, Politis AN, Arnaoutoglou CM, Karageorgos AC, Ploumis A, Xenakis TA. Accuracy of pedicle screw placement: a systematic review of prospective in vivo studies comparing free hand, fluoroscopy guidance and navigation techniques. Eur Spine J. 2012 Feb;21(2):247-55. doi: 10.1007 / s00586-011-2011-3. Epub 2011 Sep 7. PMID: 21901328; PMCID: PMC3265579]. The main advantage of this technique is the ability to virtually visualize the position of navigated instruments and implants on the navigation station monitor screen without the use of fluorography. However, this technique does not require the navigation of guide wires.The standard surgical technique for inserting guide pins through a puncture navigated needle into the vertebra involves a combination of the surgeon’s manual sensations (“blind” insertion) with mandatory radiographic control of the position of the distal end of the pin in direct and lateral radiographic projections [Park P. et al. Minimally invasive pedicle screw fixation utilizing O-arm fluoroscopy with computer-assisted navigation: feasibility, technique, and preliminary results / / Surgical neurology international. - 2010. - Vol. 1. - P. 44; http: / / www.spinaldeformity.com / Educational / Surgical%20Technique%20Guides / Medtronic / CD%20HORIZON®%20LONGITUDE®%20II%20Surgical%20Technique.pdf]. Moreover, in 32.7% of cases, radiographic control can reveal the need to correct the position of the Kirschner wires with repeat radiography [Schuetze K. et al. Spine surgery in a state-of-the-art hybrid operating room: an experience of 1745 implanted pedicle screws in the thoracolumbar spine / / Journal of Robotic Surgery.- 2023. - T. 17. - No. 4. - pp. 1365-1370].

[0003] This technique for inserting guide pins during percutaneous TPF negates the benefits of intraoperative CT navigation in reducing the radiation dose and creates additional risk for medical staff and the patient. In this regard, some researchers have proposed performing percutaneous TPF under intraoperative CT navigation without using Kirschner wires [Gianaris TJ, Helbig GM, Horn EM Percutaneous pedicle screw placement with computer-navigated mapping in place of Kirschner wires / / Journal of Neurosurgery: Spine. - 2013. - Vol. 19. - No. 5. - Pp. 608-613]. However, this technique has not received widespread use, probably due to the increased risk of screw malposition.

[0004] Official instrument sets for percutaneous TPF under CT navigation do not include devices for navigating the guide wire (Kirschner).

[0005] Our device visualizes the distal portion of the navigated needle on the navigation station monitor screen, allowing for continuous monitoring of its position relative to the spine and other navigated instruments, without the use of additional X-rays. The device's operating principle is based on a previously developed technology for capturing and fusing patient CT data with the position of the instrument in the surgical field using optical infrared conjugation.

[0006] The purpose of the utility model is to improve the safety of percutaneous TPF under intraoperative CT navigation, through navigation and precise positioning of guide pins, thereby reducing the frequency of malposition of implanted cannulated screws and preventing damage to vascular and neural structures, as well as reducing radiation exposure to medical personnel and the patient.

[0007] The solution to the stated problem is ensured by the fact that the device for frameless navigation consists of two bushings, coaxially connected to each other by means of a housing with a locking screw, characterized in that the bushings form a single axial hole, with a diameter of no more than 3 mm, for placing a guide spoke in it, with the possibility of fixing it inside the axial hole using a locking screw through a threaded hole in the housing, on the opposite side of which there is another threaded hole and slots for attaching a tracker retainer of the navigation system, the shapes and sizes of which depend on the configuration of the tracker retainer.

[0008] This goal is achieved by temporarily fixing the device to the Kirschner wire and optically coupling it to the navigation system. This ensures visualization of the wire on the navigation station monitor screen as it is guided through a pre-installed puncture needle or cannulated instrument at any stage of implantation. This allows the surgeon to accurately determine the position of the guide wire at any time without resorting to additional X-ray control.

[0009] If migration of a previously inserted guide wire is suspected during surgery, its position can be rechecked by re-positioning the Device on the guide wire at the level of the reference mark. The reference mark is applied to the guide wire using a sterile marker at an equal distance from the guide wire tips. This allows intraoperative monitoring of guide wire position at any stage of implantation, eliminating additional radiation exposure for the patient and the surgical team.

[0010] Fig. 1 shows a diagram of the device, and Fig. 2 shows the external appearance of the device. The device consists of two bushings (1), coaxially connected to each other by means of a housing (2) with a locking screw (3). A distinctive feature of the utility model is that the bushings form a single axial hole with a maximum diameter of no more than 3 mm, which allows the navigation spoke (4) to be fixed in the device using a locking screw (3). On the opposite side of the housing (2) there is a threaded hole and slots designed to secure the tracker from the navigation system. The size and shape of the hole and slots strictly depend on the configuration of the tracker retainer and can have various design options.

[0011] Thus, the Frameless Navigation Device is a utility model with the necessary characteristics for navigating a pin pre-installed before transpedicular screw insertion into a vertebra. The utility model ensures reliable and accurate performance of its intended tasks and has the necessary technical characteristics for use with navigation equipment.

[0012] Clinical case. Patient H., 57 years old. Diagnosis: LIII-LIV spondylodiscitis. Due to pain and signs of spinal instability, the following surgery was performed: LIII-LIV discectomy, spondylodiscitis debridement, interbody fusion with a titanium mesh, and percutaneous TPF under intraoperative CT navigation. Partial resection of the vertebral bodies affected by the purulent process complicated the process of screw implantation into the LV vertebral body. A decision was made to use a device to reduce the risk of screw malposition. Fig. 3 shows the use of the device at the stages of registering the guide pin through conjugation with the reference frame (Fig. 3-a), and inserting the pin into the vertebra through a Yamshidi needle (Fig. 3-b). Achieving optimal depth and position of the pin was ensured by optical coupling with the navigation system (Fig. 4). Accurate placement of screws in the vertebral bodies was confirmed by control computed tomography (Fig. 5).

Claims

A device for intraoperative navigation of a guide pin during percutaneous transpedicular fixation of the spine, consisting of two bushings coaxially connected to each other by means of a housing with a locking screw, characterized in that the device is designed with the possibility of fixation on the pin and optical coupling with a navigation station, wherein the bushings form a single axial hole with a diameter of no more than 3 mm for placing a guide pin in it, with the possibility of fixing the guide pin inside the axial hole using a locking screw through a threaded hole in the housing, on the opposite side of which a second threaded hole and slots for fastening the tracker retainer of the navigation station are made, the shapes and dimensions of which are made in accordance with the configuration of the tracker retainer.

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