Yinge Wang1, Jiajia Wang2, Sha Tu3, Shuang Li2, Jiangpu Yi4, Haien Zhao2, Huanhuan Qiao2, Kang Yan5, Bo Liao6. 1. Department of Orthopedics, The Second Affiliated Hospital of Air Force Medical University, Xi'an, Shaanxi, China; Department of Orthopedics, The 922nd Hospital of Joint Logistics Support Force, Hengyang, Hunan, China. 2. Department of Orthopedics, The Second Affiliated Hospital of Air Force Medical University, Xi'an, Shaanxi, China. 3. Department of Nutrition, The 922nd Hospital of Joint Logistics Support Force, Hengyang, Hunan, China. 4. 3D Printing Research Center, The Second Affiliated Hospital of Air Force Medical University, Xi'an, Shaanxi, China. 5. Department of Orthopedics, The Second Affiliated Hospital of Air Force Medical University, Xi'an, Shaanxi, China. Electronic address: YanKang@fmmu.edu.cn. 6. Department of Orthopedics, The Second Affiliated Hospital of Air Force Medical University, Xi'an, Shaanxi, China. Electronic address: liaobo@fmmu.edu.cn.
Abstract
OBJECTIVE: The oblique lateral locking plate system (OLLPS) is a novel internal fixation with a locking and reverse pedicle track screw configuration designed for oblique lumbar interbody fusion (OLIF). The OLLPS is placed in a single position through the oblique lateral surgical corridor to reduce operative time and complications associated with prolonged anesthesia and prone positioning. The purpose of this study was to verify the biomechanical effect of the OLLPS. METHODS: An intact finite element model of L1-S1 (intact) was established based on computed tomography images of a healthy male volunteer. The L4-L5 intervertebral space was selected as the surgical segment. The surgical models were established separately based on OLIF surgical procedures and different internal fixations: 1) stand-alone OLIF (SA); 2) OLIF with a 2-screw lateral plate; 3) OLIF with a 4-screw lateral plate; 4) OLIF with OLLPS; and 5) OLIF with bilateral pedicle screw fixation (BPS). After validation of the intact model, physiologic loads were applied to the superior surface of L1 to simulate motions such as flexion, extension, left bending, right bending, left rotation, and right rotation. The evaluation indices included the L4/5 range of motion, the L4 maximum displacement, and the maximum stresses of the superior and inferior end plates, the cage, and the supplemental fixation. RESULTS: During OLIF surgery, the OLLPS provided multiplanar stability similar to that provided by BPS. Compared with 2-screw lateral plate and 4-screw lateral plate, OLLPS had better biomechanical properties in terms of enhancing the instant stability of the surgical segment, reducing the stress on the superior and inferior end plates of the surgical segment, and decreasing the risk of cage subsidence. CONCLUSIONS: With a minimally invasive background, the OLLPS can be used as an alternative to BPS in OLIF and it has better prospects for clinical promotions and applications.
OBJECTIVE: The oblique lateral locking plate system (OLLPS) is a novel internal fixation with a locking and reverse pedicle track screw configuration designed for oblique lumbar interbody fusion (OLIF). The OLLPS is placed in a single position through the oblique lateral surgical corridor to reduce operative time and complications associated with prolonged anesthesia and prone positioning. The purpose of this study was to verify the biomechanical effect of the OLLPS. METHODS: An intact finite element model of L1-S1 (intact) was established based on computed tomography images of a healthy male volunteer. The L4-L5 intervertebral space was selected as the surgical segment. The surgical models were established separately based on OLIF surgical procedures and different internal fixations: 1) stand-alone OLIF (SA); 2) OLIF with a 2-screw lateral plate; 3) OLIF with a 4-screw lateral plate; 4) OLIF with OLLPS; and 5) OLIF with bilateral pedicle screw fixation (BPS). After validation of the intact model, physiologic loads were applied to the superior surface of L1 to simulate motions such as flexion, extension, left bending, right bending, left rotation, and right rotation. The evaluation indices included the L4/5 range of motion, the L4 maximum displacement, and the maximum stresses of the superior and inferior end plates, the cage, and the supplemental fixation. RESULTS: During OLIF surgery, the OLLPS provided multiplanar stability similar to that provided by BPS. Compared with 2-screw lateral plate and 4-screw lateral plate, OLLPS had better biomechanical properties in terms of enhancing the instant stability of the surgical segment, reducing the stress on the superior and inferior end plates of the surgical segment, and decreasing the risk of cage subsidence. CONCLUSIONS: With a minimally invasive background, the OLLPS can be used as an alternative to BPS in OLIF and it has better prospects for clinical promotions and applications.