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2022, Vol. 26 ›› Issue (3): 329-333Biomechanical stability of endoscopic transforaminal lumbar interbody fusion with unilateral pedicle screw combined with contralateral translaminar facet screw fixationLin Boying1, Shen Mao2
Abstract: BACKGROUND: Endoscopic transforaminal lumbar interbody fusion is a breakthrough technique for effective treatment of lumbar degenerative diseases. It has the advantages of less trauma, fast recovery, less bleeding, clear vision of water medium, decompression of nerve roots under direct vision, and treatment of the endplate under direct vision to increase the fusion rate. At present, there are few researches on the internal fixation based on endoscopic transforaminal lumbar interbody fusion. OBJECTIVE: To observe the effect of unilateral pedicle screw combined with contralateral translaminar facet screw fixation, unilateral pedicle screw fixation, and bilateral pedicle screw fixation on the biomechanics of lumbar vertebra after endoscopic transforaminal lumbar interbody fusion and to verify the reliability and effectiveness of unilateral pedicle screw combined with contralateral translaminar facet screw fixation. METHODS: By establishing an element model of endoscopic transforaminal lumbar interbody fusion, the effects of unilateral pedicle screw combined with contralateral translaminar facet screw fixation, unilateral pedicle screw fixation, and bilateral pedicle screw fixation on the overall displacement of the model, stress of intervertebral fusion cage and pedicle screw, and stress-strain of adjacent discs were analyzed. RESULTS AND CONCLUSION: (1) Compared with unilateral pedicle screw combined with contralateral translaminar facet screw fixation, overall displacement, screw and rod system stress, and intervertebral cage stress were significantly increased in models with unilateral pedicle screw fixation. (2) Overall displacement, screw and rod system stress, and intervertebral cage stress were basically the same under six operating conditions between the bilateral pedicle screw fixation and unilateral pedicle screw combined with contralateral translaminar facet screw fixation. (3) There was no significant difference in the stress of the adjacent intervertebral disc under the three fixation methods, and the change trend was basically the same. (4) It is confirmed that unilateral pedicle screw combined with contralateral translaminar facet screw fixation have good biomechanical properties. Key words:translaminar facet screw, endoscopic, transforaminal lumbar interbody fusion, unilateral fixation, bilateral fixation, finite element analysis |