VERTEBRAL BODY ENDOPROSTHESIS FOR LOW INVASIVE (THORACOSCOPIC) SPONDYLOSYNDESIS, INSTRUMENT FOR ENDOPROSTHESIS IMPLANTATION WITH LOCKING DEVICE, AND METHOD FOR CLAIMED ENDOPROSTHESIS INSTALLATION WITH CLAIMED TOOLS AND LOCKING DEVICE Russian patent published in 2017 - IPC A61F2/44 A61F2/46 

FIELD: medicine.

SUBSTANCE: vertebral body prosthesis for low invasive spondylosyndesis is made in the form of a hollow cylinder. Surfaces that are not in contact with the bone slot walls, have a smooth surface without holes for osseointegration. The front and posterolateral surfaces that are in contact with the bone slot walls, have circumferential rows of holes intended for autobone material osseointegration in the endoprosthesis cavity into a damaged vertebral bone after slot formation therein. The entire circumference of the cylinder has separating grooves for cylinder cutting, spaced at a distance and at an angle relative to each other, passing through the rows of holes on its front and posterolateral surfaces and conventionally dividing the endoprosthesis into sections. The anterolateral surface has a longitudinal series of holes intended for locking device mounting. A tool for implantation of the said vertebral body hollow prosthesis with a prosthesis fixing device is designed as an impactor key consisting of outer and inner parts. The outer part is designed for direct introduction of the endoprosthesis, it is T-shaped and consists of a rod represented by a tube connected to the handle and froming an assembly. The handle has a through hole that extends and equal to inner hole of the rod. The impactor key interior comprises a rod and a removable T-handle. The removable T-handle consists of a handle and a base with a polygonal hole in a suitable form to insert the rod. The rod may be formed as a polyhedron or have a polyhedron portion at the unthreaded end, where the handle is put on, and has a hole with an internal thread at the other end in the center, designed for screwing a locking device consisting of a bolt and a nut. The bolt is installed from the inside of the endoprosthesis through one hole of the row of holes on the anterolateral surface, and the nut fixes it on the outside. The installation method of the said endoprosthesis by means of the said tool with a locking device includes low invasive ventral or thoracoscopic access, bone groove formation by resection of the bone tissue of the damaged vertebra, endoprosthesis installation from the interior to one of the holes located on the anterolateral surface of the locking device in the form of a fixing bolt, which is attached to the endoprosthesis by the nut from the outside, and endoprothesis filling with bone autotransplants or osteoinductive material, lowering in the chest cavity, and then deployment and retention, so that the anterolateral surface with the lockinging device was directed towards the surgical wound. Next, the implantation tool in the form of an impactor key is fixed to the remaining end of the bolt rod fix, for this, the impactor key interior is introduced via low minimally invasive ventral or thoracoscopic access and fixed to the protruding part of the bolt rod fixed to the endoprosthesis, twirling the impactor key interior with a threaded hole located at one end of the rod, using the T-shaped handle at the other end. Next, the outer T-shaped portion is imposed over the impactor key interior, after T-handle removal from the impactor key interior. The endoprothesis is introduced in the formed bone groove of the damaged vertebra by tapping on the impactor key outer T-shaped part with rod abutting directly against the endoprosthesis surface around the locking device nut. After endoprothesis introduction in the damaged vertebra body, the impactor key is dismantled by removing the outer part and unscrewing the interior rod from the fixing bolt rod. After impactor key removal, the nut is unscrewed.

EFFECT: invention provides minimally invasive implantation of the vertebral body prosthesis with low surgical access and large surgical wound depth for thoracic and lumbar spine bodies reconstruction after total or subtotal removal thereof in case of traumatic, inflammatory and neoplastic spine lesions, improved results of surgical treatment, reduced implantation time and reduced blood loss due to hard temporary locking device fixation to the deivery tool and implant, and more accurate and fast introduction in the bone groove prepared for implantation, simplified design, allowing to form an prosthesis of required size with faces having an angle corresponding to the angle of the end plates of adjacent vertebrae, allowing endoprosthesis filling with autobone material in sufficient quantities to form a fusion, and helping to reduce the risk of endoprosthesis migration, implementation of the possibility to fix the prosthesis to the tool directly in the surgical wound, preventing the late endoprosthesis migration due to creation of optimal conditions for high-grade biopolymer-bone block formation.

7 cl, 12 dwg