METHOD OF SURGICAL FIXATION OF A ZONE OF BILATERAL SPONDYLOLYSIS OF L5 VERTEBRA USING A FIXING DEVICE WITH TRANSPEDICULAR POLYAXIAL SCREWS Russian patent published in 2023 - IPC A61B17/70 

FIELD: medicine; traumatology; orthopedics; neurosurgery.

SUBSTANCE: invention can be used for surgical treatment of a zone of bilateral spondylolysis of the L₅ vertebra using a fixation device with transpedicular polyaxial screws. An incision is made in the skin and subcutaneous fat along the line of the spinous processes. The top point of the incision is determined in the projection L₃-L₄ of the vertebrae and the incision is made to the level of L₅-S₁ with exposure of the bone tissue of the posterior vertebrae. At the intersection of the horizontal lines drawn through the upper third of the transverse processes of L₅ vertebra on the left and right, and the vertical lines drawn through the middle of the left and right facet joints of L₄-L₅ vertebrae, the posterior elements of the spine are skeletonized and hemostasis is performed. Using nippers, the lateral parts of L₅-S₁ facet joints are resected on the left and right. In the body of L₅ vertebra one fixing transpedicular polyaxial screw on the left and right for L₅ vertebra with a diameter of 5 to 7 mm and a length of 40 to 50 mm are installed. The arch of L₅ vertebra is exposed, the interspinous ligament L₅-S₁ is removed with pliers, while the supraspinous ligament L₅-S₁ is preserved, the zones of spondylolysis in the defect of the interarticular part of the arch of L₅ vertebra on the left and right are treated using Volkmann's spoons or a high-speed drill. A fixing device in the form of a metal fixing shaped plate is placed along the relief of the arch of L₅ vertebra, made using the results of computed tomography in accordance with the relief of the arch of L₅ vertebra of the patient, to fix the zone of bilateral spondylolysis of L₅ vertebra. The lower part of the fixing device is curved and repeats the anatomical relief of L₅ arch of the patient's vertebra, the lateral parts are provided with fixed rods along their edges curved taking into account their placement and subsequent fixation using locking nuts in the slots of the heads of the polyaxial screws of L₅ vertebra on the left and right. The width of the slots in the heads of the fixing transpedicular polyaxial screws is made corresponding to the diameter of the fixing rods of the lateral part of the fixing device, the heads of each transpedicular polyaxial fixing screw are pivotally connected using a self-aligning ball joint with its threaded part. The nut of the first transpedicular polyaxial fixing screw is preliminarily tightened so that the head can be moved along the upper part of the fixing rod to fix the zone of bilateral spondylolysis of L₅ vertebra, then the nut of the second transpedicular polyaxial fixing screw is screwed in the head of the second transpedicular polyaxial fixing screw. Using a contractor, the head of the first transpedicular polyaxial fixing screw is pressed against the lower part of the fixing rod to fix the zone of bilateral spondylolysis of L₅ vertebra. The head of the first transpedicular polyaxial fixing screw is moved along the horizontal part of the upper part of the fixing rod to fix the zone of bilateral spondylolysis of L₅ vertebra and create compression in the area of spondylolysis. The final fixation of the nut of the first lumbar transpedicular polyaxial fixing screw is performed, the head of the second lumbar transpedicular polyaxial fixing screw is pressed using a contractor to the lower part of the fixing rod, taking into account their installation in the heads of the lumbar fixing screws of L₅ vertebra. The head of the second lumbar fixing transpedicular polyaxial screw is moved along the horizontal upper part of the fixing rod to fix the zone of bilateral spondylolysis of L₅ vertebra and create compression in the area of spondylolysis. The final fixation of the nut of the second lumbar transpedicular polyaxial fixation screw is performed. In this case, the fixing device and transpedicular polyaxial fixing screws with nuts are made of a titanium alloy or stainless steel for medical purposes.

EFFECT: method makes it possible to perform reduction of the vertebrae, exclude disturbances in the anatomy of the posterior sections of the spine, reduce the rehabilitation period and improve the quality of life of patients due to the conformity of the fixing device used.

2 cl, 3 dwg, 3 ex