1
|
Chen J, Lu S, Chen Y, Zhang X, Xi Z, Xie L, Li J. Space between bone cement and bony endplate can trigger higher incidence of augmented vertebral collapse: An in-silico study. J Clin Neurosci 2024; 125:152-158. [PMID: 38815301 DOI: 10.1016/j.jocn.2024.05.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 05/15/2024] [Accepted: 05/16/2024] [Indexed: 06/01/2024]
Abstract
BACKGROUND The pathogenesis of postoperative complications in patients with osteoporotic vertebral compressive fractures (OVCFs) undergoing percutaneous vertebroplasty (PVP) is multifaceted, with local biomechanical deterioration playing a pivotal role. Specifically, the disparity in stiffness between the bone cement and osteoporotic cancellous bone can precipitate interfacial stress concentrations, potentially leading to cement-augmented vertebral body collapse and clinical symptom recurrence. This study focuses on the biomechanical implications of the space between the bone cement and bony endplate (BEP), hypothesizing that this interface may be a critical locus for stress concentration and subsequent vertebral failure. METHODS Leveraging a validated numerical model from our previous study, we examined the biomechanical impact of the cement-BEP interface in the L2 vertebral body post-PVP, simulated OVCF and PVP and constructed three distinct models: one with direct bone cement contact with both cranial and caudal BEPs, one with contact only with the caudal BEPs and one without contact with either BEP. Moreover, we assessed stress distribution across cranial and caudal BEPs under various loading conditions to describe the biomechanical outcomes associated with each model. RESULTS A consistent trend was observed across all models: the interfaces between the bone cement and cancellous bone exhibited higher stress values under the majority of loading conditions compared to models with direct cement-BEP contact. The most significant difference was observed in the flexion loading condition compared to the mode with direct contact between BEP and cement. The maximum stress in models without direct contact increased by at least 30%. CONCLUSIONS Our study reveals the biomechanical significance of interfacial stiffness differences at the cement-BEP junction, which can exacerbate local stress concentrations and predispose to augmented vertebral collapse. We recommend the strategic distribution of bone cement to encompass a broader contact area with the BEP for preventing biomechanical failure and subsequent vertebral collapse.
Collapse
Affiliation(s)
- Ji Chen
- Department of Orthopedics, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Third Clinical Medical College, Nanjing University of Chinese Medicine, Nanjing 210028, Jiangsu Province, PR China; Orthopedic Center, Kunshan Hospital of Traditional Chinese Medicine Kunshan, Soochow 215300, Jiangsu Province, PR China
| | - Shihao Lu
- Naval Medical University, Xiangyin Road, Shanghai 200433, PR China
| | - Yong Chen
- Orthopedic Center, Kunshan Hospital of Traditional Chinese Medicine Kunshan, Soochow 215300, Jiangsu Province, PR China
| | - Xiang Zhang
- Orthopedic Center, Kunshan Hospital of Traditional Chinese Medicine Kunshan, Soochow 215300, Jiangsu Province, PR China
| | - Zhipeng Xi
- Department of Orthopedics, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Third Clinical Medical College, Nanjing University of Chinese Medicine, Nanjing 210028, Jiangsu Province, PR China
| | - Lin Xie
- Department of Orthopedics, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Third Clinical Medical College, Nanjing University of Chinese Medicine, Nanjing 210028, Jiangsu Province, PR China.
| | - Jingchi Li
- Department of Orthopedics, Luzhou Key Laboratory of Orthopedic Disorders, The Affiliated Traditional Chinese Medicine Hospital, Southwest Medical University, NO.182, Chunhui Road, Longmatan District, Luzhou, Sichuan Province, PR China.
| |
Collapse
|
2
|
Cha X, Zhou Q, Li J, Xu H, Xu W, Li J. Extending the intermedullary nail will not reduce the potential risk of femoral head varus in PFNA patients biomechanically: a clinical review and corresponding numerical simulation. BMC Musculoskelet Disord 2024; 25:405. [PMID: 38783225 PMCID: PMC11112938 DOI: 10.1186/s12891-024-07334-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Accepted: 03/05/2024] [Indexed: 05/25/2024] Open
Abstract
Femoral head varus is an important complication in intertrochanteric fracture patients treated with proximal femoral nail anti-rotation (PFNA) fixation. Theoretically, extending the length of the intramedullary nail could optimize fixation stability by lengthening the force arm. However, whether extending the nail length can optimize patient prognosis is unclear. In this study, a review of imaging data from intertrochanteric fracture patients with PFNA fixation was performed, and the length of the intramedullary nail in the femoral trunk and the distance between the lesser trochanter and the distal locking screw were measured. The femoral neck varus status was judged at the 6-month follow-up. The correlation coefficients between nail length and femoral neck varus angle were computed, and linear regression analysis was used to determine whether a change in nail length was an independent risk factor for femoral neck varus. Moreover, the biomechanical effects of different nail lengths on PFNA fixation stability and local stress distribution have also been verified by numerical mechanical simulations. Clinical review revealed that changes in nail length were not significantly correlated with femoral head varus and were also not an independent risk factor for this complication. In addition, only slight biomechanical changes can be observed in the numerical simulation results. Therefore, commonly used intramedullary nails should be able to meet the needs of PFNA-fixed patients, and additional procedures for longer nail insertion may be unnecessary.
Collapse
Affiliation(s)
- Xiaofeng Cha
- Department of Orthopaedics, Luzhou Hospital of Traditional Chinese Medicine, Luzhou, Sichuan Province, 646000, P.R. China
| | - Qin Zhou
- Department of Orthopaedics, Luzhou Hospital of Traditional Chinese Medicine, Luzhou, Sichuan Province, 646000, P.R. China
| | - Jujie Li
- Department of Orthopaedics, Luzhou Hospital of Traditional Chinese Medicine, Luzhou, Sichuan Province, 646000, P.R. China
| | - Hong Xu
- Department of Orthopaedics, Luzhou Hospital of Traditional Chinese Medicine, Luzhou, Sichuan Province, 646000, P.R. China
| | - Wenqiang Xu
- Department of Orthopaedics, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu Province, 210028, P.R. China.
| | - Jingchi Li
- Department of Orthopedics, Luzhou Key Laboratory of Orthopedic Disorders, The Affiliated Traditional Chinese Medicine Hospital, Southwest Medical University, Luzhou, Sichuan Province, P.R. China.
| |
Collapse
|
3
|
Zou Y, Ji S, Yang HW, Ma T, Fang YK, Wang ZC, Liu MM, Zhou PH, Bao ZQ, Zhang CC, Ye YC. Biomechanical Evaluation of 2 Endoscopic Spine Surgery Methods for Treating Lumbar Disc Herniation: A Finite Element Study. Neurospine 2024; 21:273-285. [PMID: 38317559 PMCID: PMC10992651 DOI: 10.14245/ns.2347076.538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Revised: 11/22/2023] [Accepted: 12/05/2023] [Indexed: 02/07/2024] Open
Abstract
OBJECTIVE This study aimed to evaluate the effects of 2 endoscopic spine surgeries on the biomechanical properties of normal and osteoporotic spines. METHODS Based on computed tomography images of a healthy adult volunteer, 6 finite element models were created. After validating the normal intact model, a concentrated force of 400 N and a moment of 7.5 Nm were exerted on the upper surface of L3 to simulate 6 physiological activities of the spine. Five types of indices were used to assess the biomechanical properties of the 6 models, range of motion (ROM), maximum displacement value, intervertebral disc stress, maximum stress value, and articular protrusion stress, and by combining them with finite element stress cloud. RESULTS In normal and osteoporotic spines, there was no meaningful change in ROM or disc stress in the 2 surgical models for the 6 motion states. Model N1 (osteoporotic percutaneous transforaminal endoscopic discectomy model) showed a decrease in maximum displacement value of 20.28% in right lateral bending. Model M2 (unilateral biportal endoscopic model) increased maximum displacement values of 16.88% and 17.82% during left and right lateral bending, respectively. The maximum stress value of L4-5 increased by 11.72% for model M2 during left rotation. In addition, using the same surgical approach, ROM, maximum displacement values, disc stress, and maximum stress values were more significant in the osteoporotic model than in the normal model. CONCLUSION In both normal and osteoporotic spines, both surgical approaches were less disruptive to the physiologic structure of the spine. Furthermore, using the same endoscopic spine surgery, normal spine biomechanical properties are superior to osteoporotic spines.
Collapse
Affiliation(s)
- Yang Zou
- Department of Orthopaedics, The First Affiliated Hospital of Bengbu Medical College, Bengbu, China
- Anhui Province Key Laboratory of Tissue Transplantation, Bengbu Medical College, Bengbu, China
| | - Shuo Ji
- Anhui Province Key Laboratory of Tissue Transplantation, Bengbu Medical College, Bengbu, China
| | - Hui Wen Yang
- Department of Orthopaedics, The First Affiliated Hospital of Bengbu Medical College, Bengbu, China
- Anhui Province Key Laboratory of Tissue Transplantation, Bengbu Medical College, Bengbu, China
| | - Tao Ma
- Department of Orthopaedics, The First Affiliated Hospital of Bengbu Medical College, Bengbu, China
- Anhui Province Key Laboratory of Tissue Transplantation, Bengbu Medical College, Bengbu, China
| | - Yue Kun Fang
- Anhui Province Key Laboratory of Tissue Transplantation, Bengbu Medical College, Bengbu, China
| | - Zhi Cheng Wang
- Anhui Province Key Laboratory of Tissue Transplantation, Bengbu Medical College, Bengbu, China
| | - Miao Miao Liu
- Department of Orthopaedics, The First Affiliated Hospital of Bengbu Medical College, Bengbu, China
| | - Ping Hui Zhou
- Department of Orthopaedics, The First Affiliated Hospital of Bengbu Medical College, Bengbu, China
- Anhui Province Key Laboratory of Tissue Transplantation, Bengbu Medical College, Bengbu, China
| | - Zheng Qi Bao
- Department of Orthopaedics, The First Affiliated Hospital of Bengbu Medical College, Bengbu, China
- Anhui Province Key Laboratory of Tissue Transplantation, Bengbu Medical College, Bengbu, China
| | - Chang Chun Zhang
- Department of Orthopaedics, The First Affiliated Hospital of Bengbu Medical College, Bengbu, China
- Anhui Province Key Laboratory of Tissue Transplantation, Bengbu Medical College, Bengbu, China
| | - Yu Chen Ye
- Department of Orthopaedics, The First Affiliated Hospital of Bengbu Medical College, Bengbu, China
- Anhui Province Key Laboratory of Tissue Transplantation, Bengbu Medical College, Bengbu, China
| |
Collapse
|
4
|
Huang F, Huang G, Jia J, Lu S, Li J. Intraoperative capsule protection can reduce the potential risk of adjacent segment degeneration acceleration biomechanically: an in silico study. J Orthop Surg Res 2024; 19:143. [PMID: 38365801 PMCID: PMC10870541 DOI: 10.1186/s13018-024-04550-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 01/09/2024] [Indexed: 02/18/2024] Open
Abstract
BACKGROUND The capsule of the zygapophyseal joint plays an important role in motion segmental stability maintenance. Iatrogenic capsule injury is a common phenomenon in posterior approach lumbar interbody fusion operations, but whether this procedure will cause a higher risk of adjacent segment degeneration acceleration biomechanically has yet to be identified. METHODS Posterior lumbar interbody fusion (PLIF) with different grades of iatrogenic capsule injury was simulated in our calibrated and validated numerical model. By adjusting the cross-sectional area of the capsule, different grades of capsule injury were simulated. The stress distribution on the cranial motion segment was computed under different loading conditions to judge the potential risk of adjacent segment degeneration acceleration. RESULTS Compared to the PLIF model with an intact capsule, a stepwise increase in the stress value on the cranial motion segment can be observed with a step decrease in capsule cross-sectional areas. Moreover, compared to the difference between models with intact and slightly injured capsules, the difference in stress values was more evident between models with slight and severe iatrogenic capsule injury. CONCLUSION Intraoperative capsule protection can reduce the potential risk of adjacent segment degeneration acceleration biomechanically, and iatrogenic capsule damage on the cranial motion segment should be reduced to optimize patients' long-term prognosis.
Collapse
Affiliation(s)
- Fei Huang
- Department of Orthopedics, Meishan Hospital of Traditional Chinese Medicine, Meishan, China
| | - Gang Huang
- Luzhou Key Laboratory of Orthopedic Disorders, Southwest Medical University, No. 182, Chunhui Road, Luzhou, 646000, Sichuan Province, People's Republic of China
| | - Junpengli Jia
- Luzhou Key Laboratory of Orthopedic Disorders, Southwest Medical University, No. 182, Chunhui Road, Luzhou, 646000, Sichuan Province, People's Republic of China
| | - Shihao Lu
- Department of Orthopedics, Changzheng Hospital Affiliated to the Naval Medical University, Xiangyin Road, Shanghai, 200433, People's Republic of China.
| | - Jingchi Li
- Department of Orthopedics, The Affiliated Traditional Chinese Medicine Hospital, Southwest Medical University, No. 182, Chunhui Road, Longmatan District, Luzhou, 646000, Sichuan Province, People's Republic of China.
- Luzhou Key Laboratory of Orthopedic Disorders, Southwest Medical University, No. 182, Chunhui Road, Luzhou, 646000, Sichuan Province, People's Republic of China.
| |
Collapse
|
5
|
Sun J, Wang J, Wu R, Zhao Z, Fan B, Cai J, Feng F. Comparison of bone reamer and trephine for foraminoplasty in percutaneous endoscopic lumbar discectomy based on 3D slicer and Digimizer software. J Orthop Surg Res 2024; 19:55. [PMID: 38217013 PMCID: PMC10785399 DOI: 10.1186/s13018-023-04270-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 10/07/2023] [Indexed: 01/14/2024] Open
Abstract
OBJECTIVE To explore the applicability of bone reamer and trephine for foraminoscopy in percutaneous endoscopic lumbar discectomy (PELD), and to provide a theoretical basis for foraminoplasty options in clinical practice. METHODS This study was a prospective cohort study. Sixty-three consecutive patients who underwent PELD for lumbar disc herniation between May 2021 and July 2022 were analysed. Foraminoplasty were performed by bone reamer or trephine. The amount of bone removed and the foramen area enlarged during foraminoplasty by both tools were measured by 3D slicer and Digimizer software, and the numbers of fluoroscopic views were recorded. RESULTS The bone reamer removed less bone in the Superior Articular Process (SAP) than the trephine (t = 17.507, P < 0.001), and the area enlarged by the bone reamer was smaller than that of the trephine (t = 10.042, P = 0.002). The overall numbers of fluoroscopic views were significantly more in the bone reamer group than in the trephine group (t = 19.003, P < 0.001). In the bone reamer group, when the area of preoperative (FPZ) was no less than 54.55 mm2, the mean number of fluoroscopic views significantly decreased (t = 14.443, P = 0.001). CONCLUSION Bone reamer was safer and trephine was more efficient for foraminoscopy in PELD. An area of preoperative (FPZ) of 54.55 mm2 can be used as a critical value: bone reamer reduced the risk for cases above the value, while trephine improved the efficiency for cases less than the value.
Collapse
Affiliation(s)
- Jiewei Sun
- Cardiothoracic Surgery Department, The First People's Hospital of Fuyang, No. 429, Beihuan Road, Fuchun Street, Fuyang District, Hangzhou, 311400, Zhejiang, China
| | - Jun Wang
- The orthopaedic, Xiaoshan Hospital Affiliated to Wenzhou Medical University, Hangzhou, Zhejiang, China
| | - Ruiji Wu
- Second Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, 310005, Zhejiang, China
| | - Zhi Zhao
- The orthopaedic, Xiaoshan Hospital Affiliated to Wenzhou Medical University, Hangzhou, Zhejiang, China
| | - Bingkai Fan
- The orthopaedic, Xiaoshan Hospital Affiliated to Wenzhou Medical University, Hangzhou, Zhejiang, China
| | - Jie Cai
- The orthopaedic, Xiaoshan Hospital Affiliated to Wenzhou Medical University, Hangzhou, Zhejiang, China
| | - Fabo Feng
- Center for Plastic and Reconstructive Surgery, Department of Orthopedics, Zhejiang Provincial People's Hospital (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, Zhejiang, China.
| |
Collapse
|
6
|
Liu Y, Zhang Q, Ji N, Wang J, Li J, Du J, Zhao J, Ouyang P, Qin J, Li H, Wang D. Stability simulation analysis of targeted puncture in L4/5 intervertebral space for PELD surgery. Front Bioeng Biotechnol 2024; 11:1298914. [PMID: 38260730 PMCID: PMC10800398 DOI: 10.3389/fbioe.2023.1298914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 12/20/2023] [Indexed: 01/24/2024] Open
Abstract
Introduction: The application prospects of percutaneous endoscopic lumbar discectomy (PELD) as a minimally invasive spinal surgery method in the treatment of lumbar disc herniation are extensive. This study aims to find the optimal entry angle for the trephine at the L4/5 intervertebral space, which causes less lumbar damage and has greater postoperative stability. To achieve this, we conduct a three-dimensional simulated analysis of the degree of damage caused by targeted puncture-based trephine osteotomy on the lumbar spine. Methods: We gathered clinical CT data from patients to construct a lumbar model. This model was used to simulate and analyze the variations in trephine osteotomy volume resulting from targeted punctures at the L4/5 interspace. Furthermore, according to these variations in osteotomy volume, we created Finite Element Analysis (FEA) models specifically for the trephine osteotomy procedure. We then applied mechanical loads to conduct range of motion and von Mises stress analyses on the lumbar motion unit. Results: In percutaneous endoscopic interlaminar discectomy, the smallest osteotomy volume occurred with a 20° entry angle, close to the base of the spinous process. The volume increased at 30° and reached its largest at 40°. In percutaneous transforaminal endoscopic discectomy, the largest osteotomy volume was observed with a 50° entry angle, passing through the facet joints, with smaller volumes at 60° and the smallest at 70°. In FEA, M6 exhibited the most notable biomechanical decline, particularly during posterior extension and right rotation. M2 and M3 showed significant differences primarily in rotation, whereas the differences between M3 and M4 were most evident in posterior extension and right rotation. M5 displayed their highest stress levels primarily in posterior extension, with significant variations observed in right rotation alongside M4. Conclusion: The appropriate selection of entry sites can reduce lumbar damage and increase stability. We suggest employing targeted punctures at a 30° angle for PEID and at a 60° angle for PTED at the L4/5 intervertebral space. Additionally, reducing the degree of facet joint damage is crucial to enhance postoperative stability in lumbar vertebral motion units.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | - Haopeng Li
- Department of Orthopedics, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, China
| | - Dong Wang
- Department of Orthopedics, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, China
| |
Collapse
|
7
|
Xu C, Xi Z, Fang Z, Zhang X, Wang N, Li J, Liu Y. Annulus Calibration Increases the Computational Accuracy of the Lumbar Finite Element Model. Global Spine J 2023; 13:2310-2318. [PMID: 35293827 PMCID: PMC10538312 DOI: 10.1177/21925682221081224] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
STUDY DESIGN Mechanical simulations. OBJECTIVE Inadequate calibration of annuli negatively affects the computational accuracy of finite element (FE) models. Specifically, the definition of annulus average radius (AR) does not have uniformity standards. Differences between the elastic moduli in the different layers and parts of the annulus were not fully calibrated when a linear elastic material is used to define its material properties. This study aims to optimize the computational accuracy of the FE model by calibrating the annulus. METHODS We calibrated the annulus AR and elastic modulus in our anterior-constructed lumbar model by eliminating the difference between the computed range of motion and that measured by in vitro studies under a flexion-extension loading condition. Multi-indicator validation was performed by comparing the computed indicators with those measured in in vitro studies. The computation time required for the different models has also been recorded to evaluate the computational efficiency. RESULTS The difference between computed and measured ROMs was less than 1% when the annulus AR and elastic modulus were calibrated. In the model validation process, all the indicators computed by the calibrated FE model were within ±1 standard deviation of the average values obtained from in vitro studies. The maximum difference between the computed and measured values was less than 10% under nearly all loading conditions. There is no apparent variation tendency for the computational time associated with different models. CONCLUSION The FE model with calibrated annulus AR and regional elastic modulus has higher computational accuracy and can be used in subsequent mechanical studies.
Collapse
Affiliation(s)
- Chen Xu
- Department of Spine Surgery, Shanghai Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Zhipeng Xi
- Department of Orthopedics, Jiangsu Province Hospital on Integration of Chinese and Western Medicine, Nanjing, China
| | - Zhongxin Fang
- Fluid and Power Machinery Key Laboratory of Ministry of Education, Xihua University, Chengdu, China
| | - Xiaoyu Zhang
- Department of Orthopedics, Jiangsu Province Hospital on Integration of Chinese and Western Medicine, Nanjing, China
| | - Nan Wang
- Department of Orthopedics, Jiangsu Province Hospital on Integration of Chinese and Western Medicine, Nanjing, China
| | - Jingchi Li
- Department of Spine Surgery, Shanghai Changzheng Hospital, Naval Medical University, Shanghai, China
- Department of Orthopedics, Hospital (T.C.M) Affiliated to Southwest Medical University, Luzhou, China
| | - Yang Liu
- Department of Spine Surgery, Shanghai Changzheng Hospital, Naval Medical University, Shanghai, China
| |
Collapse
|
8
|
Mu G, Yue L, Sun H. Long-Term Radiographic and Clinical Outcomes in Patients Undergoing Transforaminal Endoscopic Lumbar Discectomy: A Propensity Score Matching Study. J Pain Res 2023; 16:3019-3027. [PMID: 37674818 PMCID: PMC10478952 DOI: 10.2147/jpr.s406071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 07/04/2023] [Indexed: 09/08/2023] Open
Abstract
Background Our study aims to investigate the long-term clinical and radiographic effects of transforaminal endoscopic lumbar discectomy (TELD) on lumbar disc herniation. Patients and Methods Radiographic and clinical data of patients undergoing TELD in our institution from January 2015 to January 2019 were retrospectively collected. LDH outpatients who had not received surgical treatment during the same period were 1:1 matched by propensity score matching as the conservative group. The radiographic parameters of the two groups at baseline and at the last follow-up (≥24 months) were analyzed. Results The study included 47 patients in the TELD group, matched with 47 patients in the conservative group. The disc height of the TELD group at the last follow-up was lower than that at the baseline (P < 0.001), and lower than that of the conservative group at the last follow-up (P < 0.05). The disc degeneration grade of the TELD group at the last follow-up was greater than that at the baseline, and greater than that of the conservative group at the last follow-up. There was no significant difference in the facet joint degeneration in the TELD group between the baseline and the last follow-up, and between the TELD group and the conservative group at the last follow-up (P > 0.05). The pain intensity and disability score in the TELD group at 3-month follow-up and at the last follow-up were significantly lower than those at the baseline (P < 0.001). Six patients in the TELD group required additional surgery during the follow-up period. Conclusion Our long-term follow-up data shows that the disc height of the operated level was significantly reduced and the disc degeneration was significantly aggravated in TELD-treated patients; in contrast, the facet joint degeneration did not show significant aggravation.
Collapse
Affiliation(s)
- Guanzhang Mu
- Orthopaedic Department, Peking University First Hospital, Beijing, People’s Republic of China
| | - Lei Yue
- Orthopaedic Department, Peking University First Hospital, Beijing, People’s Republic of China
| | - Haolin Sun
- Orthopaedic Department, Peking University First Hospital, Beijing, People’s Republic of China
| |
Collapse
|
9
|
Cai P, Xi Z, Deng C, Li J, Zhang X, Zhou Y. Fixation-induced surgical segment's high stiffness and the damage of posterior structures together trigger a higher risk of adjacent segment disease in patients with lumbar interbody fusion operations. J Orthop Surg Res 2023; 18:371. [PMID: 37208705 DOI: 10.1186/s13018-023-03838-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 05/06/2023] [Indexed: 05/21/2023] Open
Abstract
BACKGROUND Adjacent segment disease (ASD) is a commonly reported complication after lumbar interbody fusion (LIF); changes in the mechanical environment play an essential role in the generation of ASD. Traditionally, fixation-induced high stiffness in the surgical segment was the main reason for ASD. However, with more attention paid to the biomechanical significance of posterior bony and soft structures, surgeons hypothesize that this factor may also play an important role in ASD. METHODS Oblique and posterior LIF operations have been simulated in this study. The stand-alone OLIF and OLIF fixed by bilateral pedicle screw (BPS) system have been simulated. The spinal process (the attachment point of cranial ligamentum complex) was excised in the PLIF model; the BPS system has also been used in the PLIF model. Stress values related to ASD have been computed under physiological body positions, including flexion, extension, bending, and axial rotations. RESULTS Compared to the stand-alone OLIF model, the OLIF model with BPS fixation suffers higher stress values under extension body position. However, there are no apparent differences under other loading conditions. Moreover, significant increases in stress values can be recorded in flexion and extension loading conditions in the PLIF model with posterior structures damage. CONCLUSIONS Fixation-induced surgical segment's high stiffness and the damage of posterior soft tissues together trigger a higher risk of ASD in patients with LIF operations. Optimizing BPS fixation methods and pedicle screw designs and reducing the range of posterior structures excision may be an effective method to reduce the risk of ASD.
Collapse
Affiliation(s)
- Ping Cai
- Department of Orthopedics, Lianyungang Hospital of Traditional Chinese Medicine, Lianyungang, Jiangsu, People's Republic of China
- Department of Orthopedics, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, Jiangsu, People's Republic of China
| | - Zhieng Xi
- Department of Spine Surgery, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, People's Republic of China
| | - Chao Deng
- Department of Orthopedics, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, Jiangsu, People's Republic of China
| | - Jingchi Li
- Department of Spine Surgery, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, People's Republic of China
| | - Xiaoyu Zhang
- Department of Spine Surgery, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, People's Republic of China
| | - Yingguang Zhou
- Department of Orthopedics, Lianyungang Hospital of Traditional Chinese Medicine, Lianyungang, Jiangsu, People's Republic of China.
| |
Collapse
|
10
|
Huang C, Liu Z, Wei Z, Fang Z, Xi Z, Cai P, Li J. Will the adjustment of insertional pedicle screw positions affect the risk of adjacent segment diseases biomechanically? An in-silico study. Front Surg 2023; 9:1004642. [PMID: 36713678 PMCID: PMC9877423 DOI: 10.3389/fsurg.2022.1004642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 09/20/2022] [Indexed: 01/13/2023] Open
Abstract
Background The fixation-induced biomechanical deterioration will increase the risk of adjacent segment diseases (ASD) after lumbar interbody fusion with Bilateral pedicle screw (BPS) fixation. The accurate adjustment of insertional pedicle screw positions is possible, and published studies have reported its mechanical effects. However, no studies clarified that adjusting insertional screw positions would affect the postoperative biomechanical environment and the risk of ASD. The objective of this study was to identify this issue and provide theoretical references for the optimization of insertional pedicle screw position selections. Methods The oblique lumbar interbody fusion fixed by BPS with different insertional positions has been simulated in the L4-L5 segment of our previously constructed and validated lumbosacral model. Biomechanical indicators related to ASD have been computed and recorded under flexion, extension, bending, and axial rotation loading conditions. Results The change of screw insertional positions has more apparent biomechanical effects on the cranial than the caudal segment. Positive collections can be observed between the reduction of the fixation length and the alleviation of motility compensation and stress concentration on facet cartilages. By contrast, no pronounced tendency of stress distribution on the intervertebral discs can be observed with the change of screw positions. Conclusions Reducing the fixation stiffness by adjusting the insertional screw positions could alleviate the biomechanical deterioration and be an effective method to reduce the risk of ASD caused by BPS.
Collapse
Affiliation(s)
- Chenyi Huang
- Department of Orthopedics, The Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University, Luzhou, China
| | - Zongchao Liu
- Department of Orthopedics, The Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University, Luzhou, China
| | - Zhangchao Wei
- Department of Orthopedics, The Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University, Luzhou, China
| | - Zhongxin Fang
- Fluid and Power Machinery Key Laboratory of Ministry of Education, Xihua University, Chengdu, China
| | - Zhipeng Xi
- Department of Spine Surgery, Jiangsu Province Hospital on Integration of Chinese and Western Medicine, Nanjing, China
| | - Ping Cai
- Department of Orthopedics, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China,Correspondence: Jingchi Li Ping Cai
| | - Jingchi Li
- Department of Orthopedics, The Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University, Luzhou, China,Correspondence: Jingchi Li Ping Cai
| |
Collapse
|
11
|
Eremina G, Smolin A, Xie J, Syrkashev V. Development of a Computational Model of the Mechanical Behavior of the L4-L5 Lumbar Spine: Application to Disc Degeneration. MATERIALS (BASEL, SWITZERLAND) 2022; 15:6684. [PMID: 36234026 PMCID: PMC9572952 DOI: 10.3390/ma15196684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/22/2022] [Accepted: 09/23/2022] [Indexed: 06/16/2023]
Abstract
Degenerative changes in the lumbar spine significantly reduce the quality of life of people. In order to fully understand the biomechanics of the affected spine, it is crucial to consider the biomechanical alterations caused by degeneration of the intervertebral disc (IVD). Therefore, this study is aimed at the development of a discrete element model of the mechanical behavior of the L4-L5 spinal motion segment, which covers all the degeneration grades from healthy IVD to its severe degeneration, and numerical study of the influence of the IVD degeneration on stress state and biomechanics of the spine. In order to analyze the effects of IVD degeneration on spine biomechanics, we simulated physiological loading conditions using compressive forces. The results of modeling showed that at the initial stages of degenerative changes, an increase in the amplitude and area of maximum compressive stresses in the disc is observed. At the late stages of disc degradation, a decrease in the value of intradiscal pressure and a shift in the maximum compressive stresses in the dorsal direction is observed. Such an influence of the degradation of the geometric and mechanical parameters of the tissues of the disc leads to the effect of bulging, which in turn leads to the formation of an intervertebral hernia.
Collapse
Affiliation(s)
- Galina Eremina
- Institute of Strength Physics and Materials Science, Siberian Branch of the Russian Academy of Sciences, Pr. Akademicheskii, 2/4, 634055 Tomsk, Russia
| | - Alexey Smolin
- Institute of Strength Physics and Materials Science, Siberian Branch of the Russian Academy of Sciences, Pr. Akademicheskii, 2/4, 634055 Tomsk, Russia
| | - Jing Xie
- State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China
| | - Vladimir Syrkashev
- Department of General Medicine, Siberian State Medical University, Moskovsky Trakt, 2, 634050 Tomsk, Russia
| |
Collapse
|
12
|
Li JC, Yang ZQ, Xie TH, Song ZT, Song YM, Zeng JC. Deterioration of the fixation segment’s stress distribution and the strength reduction of screw holding position together cause screw loosening in ALSR fixed OLIF patients with poor BMD. Front Bioeng Biotechnol 2022; 10:922848. [PMID: 36110315 PMCID: PMC9468878 DOI: 10.3389/fbioe.2022.922848] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 07/29/2022] [Indexed: 11/16/2022] Open
Abstract
The vertebral body’s Hounsfield unit (HU) value can credibly reflect patients’ bone mineral density (BMD). Given that poor bone-screw integration initially triggers screw loosening and regional differences in BMD and strength in the vertebral body exist, HU in screw holding planes should better predict screw loosening. According to the stress shielding effect, the stress distribution changes in the fixation segment with BMD reduction should be related to screw loosening, but this has not been identified. We retrospectively collected the radiographic and demographic data of 56 patients treated by single-level oblique lumbar interbody fusion (OLIF) with anterior lateral single rod (ALSR) screw fixation. BMD was identified by measuring HU values in vertebral bodies and screw holding planes. Regression analyses identified independent risk factors for cranial and caudal screw loosening separately. Meanwhile, OLIF with ALSR fixation was numerically simulated; the elastic modulus of bony structures was adjusted to simulate different grades of BMD reduction. Stress distribution changes were judged by computing stress distribution in screws, bone-screw interfaces, and cancellous bones in the fixation segment. The results showed that HU reduction in vertebral bodies and screw holding planes were independent risk factors for screw loosening. The predictive performance of screw holding plane HU is better than the mean HU of vertebral bodies. Cranial screws suffer a higher risk of screw loosening, but HU was not significantly different between cranial and caudal sides. The poor BMD led to stress concentrations on both the screw and bone-screw interfaces. Biomechanical deterioration was more severe in the cranial screws than in the caudal screws. Additionally, lower stress can also be observed in fixation segments’ cancellous bone. Therefore, a higher proportion of ALSR load transmission triggers stress concentration on the screw and bone-screw interfaces in patients with poor BMD. This, together with decreased bony strength in the screw holding position, contributes to screw loosening in osteoporotic patients biomechanically. The trajectory optimization of ALSR screws based on preoperative HU measurement and regular anti-osteoporosis therapy may effectively reduce the risk of screw loosening.
Collapse
Affiliation(s)
- Jing-Chi Li
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
| | - Zhi-Qiang Yang
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
| | - Tian-Hang Xie
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
| | - Zhe-Tao Song
- Department of Imaging, West China Hospital, Chengdu, China
| | - Yue-Ming Song
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
- *Correspondence: Yue-Ming Song, ; Jian-Cheng Zeng,
| | - Jian-Cheng Zeng
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
- *Correspondence: Yue-Ming Song, ; Jian-Cheng Zeng,
| |
Collapse
|
13
|
Li JC, Xie TH, Zhang Z, Song ZT, Song YM, Zeng JC. The Mismatch Between Bony Endplates and Grafted Bone Increases Screw Loosening Risk for OLIF Patients With ALSR Fixation Biomechanically. Front Bioeng Biotechnol 2022; 10:862951. [PMID: 35464717 PMCID: PMC9023805 DOI: 10.3389/fbioe.2022.862951] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 03/24/2022] [Indexed: 12/26/2022] Open
Abstract
The mismatch between bony endplates (BEPs) and grafted bone (GB) triggers several complications biomechanically. However, no published study has identified whether this factor increases the risk of screw loosening by deteriorating the local stress levels. This study aimed to illustrate the biomechanical effects of the mismatch between BEP and GB and the related risk of screw loosening. In this study, radiographic and demographic data of 56 patients treated by single segment oblique lumbar interbody fusion (OLIF) with anterior lateral single rod (ALSR) fixation were collected retrospectively, and the match sufficiency between BEP and GB was measured and presented as the grafted bony occupancy rate (GBOR). Data in patients with and without screw loosening were compared; regression analyses identified independent risk factors. OLIF with different GBORs was simulated in a previously constructed and validated lumbosacral model, and biomechanical indicators related to screw loosening were computed in surgical models. The radiographic review and numerical simulations showed that the coronal plane’s GBOR was significantly lower in screw loosening patients both in the cranial and caudal vertebral bodies; the decrease in the coronal plane’s GBOR has been proven to be an independent risk factor for screw loosening. In addition, numerical mechanical simulations showed that the poor match between BEP and GB will lead to stress concentration on both screws and bone-screw interfaces. Therefore, we can conclude that the mismatch between the BEP and GB will increase the risk of screw loosening by deteriorating local stress levels, and the increase in the GBOR by modifying the OLIF cage’s design may be an effective method to optimize the patient’s prognosis.
Collapse
Affiliation(s)
- Jing-Chi Li
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
| | - Tian-Hang Xie
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
| | - Zhuang Zhang
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
| | - Zhe-Tao Song
- Department of Imaging, West China Hospital, Chengdu, China
| | - Yue-Ming Song
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
- *Correspondence: Yue-Ming Song, ; Jian-Cheng Zeng,
| | - Jian-Cheng Zeng
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine for Sichuan University, Chengdu, China
- *Correspondence: Yue-Ming Song, ; Jian-Cheng Zeng,
| |
Collapse
|
14
|
Xu C, Huang C, Cai P, Fang Z, Wei Z, Liu F, Li J, Liu Y. Biomechanical Effects of Pedicle Screw Positioning on the Surgical Segment in Models After Oblique Lumbar Interbody Fusion: An in-silico Study. Int J Gen Med 2022; 15:1047-1056. [PMID: 35140507 PMCID: PMC8818966 DOI: 10.2147/ijgm.s352304] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 01/20/2022] [Indexed: 11/23/2022] Open
Abstract
Background Bilateral pedicle screw (BPS) is the “gold standard” of fixation methods for patients with lumbar interbody fusion. Biomechanical deterioration initially triggers complications in the surgical segment. Studies proved that BPS positions and trajectory changes affect the local biomechanical environment. However, no study illustrates the biomechanical effect of insertional screw positions’ change on the surgical segment. Methods Oblique lumbar interbody fusion (OLIF) with different BPS insertional positions has been simulated in a well-validated lumbo-sacral model. Fixation stability and stress responses on the surgical segment were evaluated under identical loading conditions. Results There is no clear variation tendency for the risk of BPS failure and the change of strain energy density of the grafted bone. However, shifting the insertional screw position close to the surgical segment will increase the range of motions (ROM) in the surgical segment and lead to stress concentration of bony structures, especially in the caudal side of the surgical segment. Conclusion Adjusting the insertional position of BPS close to the surgical segment in OLIF models will lead to stress concentration of bony structures and surgical segmental instability. Therefore, reducing BPS’s fixation length was not recommended, which may increase the risk of segmental instability, non-union, and cage subsidence.
Collapse
Affiliation(s)
- Chen Xu
- Department of Spine Surgery, Shanghai Changzheng Hospital, Naval Medical University, Shanghai, 200003, People’s Republic of China
| | - Chenyi Huang
- Department of Orthopedics, Hospital (T.C.M) Affiliated to Southwest Medical University, Luzhou, 646000, Sichuan, People’s Republic of China
| | - Ping Cai
- Department of Orthopedics, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, Jiangsu, People’s Republic of China
| | - Zhongxin Fang
- Fluid and Power Machinery Key Laboratory of Ministry of Education, Xihua University, Chengdu, People’s Republic of China
| | - Zhangchao Wei
- Department of Orthopedics, Hospital (T.C.M) Affiliated to Southwest Medical University, Luzhou, 646000, Sichuan, People’s Republic of China
| | - Fei Liu
- Department of Orthopedics, Hospital (T.C.M) Affiliated to Southwest Medical University, Luzhou, 646000, Sichuan, People’s Republic of China
| | - Jingchi Li
- Department of Spine Surgery, Shanghai Changzheng Hospital, Naval Medical University, Shanghai, 200003, People’s Republic of China
- Department of Orthopedics, Hospital (T.C.M) Affiliated to Southwest Medical University, Luzhou, 646000, Sichuan, People’s Republic of China
- Jingchi Li, Department of Orthopedics, Hospital (T.C.M) Affiliated to Southwest Medical University, No. 182, Chunhui Road, Luzhou, Sichuan Province, 646000, People’s Republic of China, Email
| | - Yang Liu
- Department of Spine Surgery, Shanghai Changzheng Hospital, Naval Medical University, Shanghai, 200003, People’s Republic of China
- Correspondence: Yang Liu, Department of Spine Surgery, Shanghai Changzheng Hospital, Naval Medical University, 415th Fengyang Road, Shanghai, 200003, People’s Republic of China, Email
| |
Collapse
|
15
|
Negative biomechanical effects of large grade nuclectomy in the transforaminal endoscopic discectomy increased the risk of adjacent segment diseases: A finite element study. J Clin Neurosci 2021; 93:141-146. [PMID: 34656238 DOI: 10.1016/j.jocn.2021.09.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 09/05/2021] [Accepted: 09/07/2021] [Indexed: 11/20/2022]
Abstract
PURPOSE The protection of articular processes (AP) in the transforaminal endoscopic discectomy (TED) was proven to optimise post-operative biomechanical environments. Published studies reported a large grade of nuclectomy leading to poor prognosis, but the underlying biomechanical mechanism was unclearly illustrated. This study aimed to investigate the changes of biomechanical environments after an in-out TED with intact AP and a large grade of nuclectomy and an out-in TED with limited foraminoplasty and a smaller grade of nuclectomy. METHODS A previously constructed and validated lumbo-sacral model was used in this study, and in-out TED with intact AP and out-in TED with limited foraminoplasty, a smaller grade of nuclectomy was simulated. Biomechanical changes in the L5-S1 segment related to the degeneration acceleration were computed under different directional loading conditions. RESULTS Post-operative biomechanical changes after the out-in TED with limited foraminoplasty were slight, except for the facet contact pressure under the extension position. By contrast, significant biomechanical deterioration, both in the adjacent disc and zygapophyseal joints, is observed under extension in the model after the in-out TED with large nuclectomy. CONCLUSION A large grade of nuclectomy is regarded as an independent risk factor of adjacent segment disease in the caudal functional spinal unit after the in-out TED.
Collapse
|