Oblique lateral interbody fusion with internal fixations in the treatment for cross-segment degenerative lumbar spine disease (L2-3 and L4-5) finite element analysis.

Multi-segmental lumbar degenerative disease, including intersegmental disc degeneration, is found in clinical practice. Controversy still exists regarding the treatment for cross-segment degeneration. Oblique Lateral Interbody Fusion (OLIF) with several internal fixations was used to treat cross-segment lumbar degenerative disease. A whole lumbar spine model was extracted from CT images of the whole lumbar spine of patients with lumbar degeneration. The L2-3 and L4-5 intervertebral spaces were fused with OLIF using modeling software, the Pedicle screws were performed on L2-3 and L4-5, and different internal fixations were performed on L3-4 in Finite Element (FE) software. Among the six 10 Nm moments of different directions, the L3-4 no surgery (NS) group had the relatively largest Range of Motion (ROM) in the whole lumbar spine, while the L2-5 Long segmental fixation (LSF)group had the smallest ROM and the other groups had similar ROM. The ROM in the L1-2 and L5-S1 was relatively close in the six group models, and the articular cartilage stress and disc stress on the L1-2 and L5-S1 were relatively close. In contrast, the L3-4 ROM differed relatively greatly, with the LSF ROM the smallest and the NS ROM the largest, and the L3-4 Coflex (Coflex) group more active than the L3-4 Bacfuse (Bacfuse) group and the L3-4 translaminar facet screw fixation (TFSF) group. The stress on the articular cartilage and disc at L3-4 was relatively greater in the NS disc and articular cartilage, and greater in the Coflex group than in the Bacfuse and TFSF groups, with the greatest stress on the internal fixation in the TFSF group, followed by the Coflex group, and relatively similar stress in the Bacfuse, LSF, and NS groups. In the TFSF group, the stress on the internal fixation was greater than the yield strength among different directional moments of 10 Nm, which means it is unsuitable to be an internal fixation. The LSF group had the greatest overall ROM, which may lead to postoperative low back discomfort. The NS group has the greatest overall ROM, but its increased stress on the L3-4 disc and articular cartilage may lead to accelerated degeneration of the L3-4 disc and articular cartilage. The Coflex and Bacfuse groups had a reduced L3-4 ROM but a greater stress on disc compared to the LSF group, which may lead to disc degeneration in the long term. However, their stress on the articular cartilage was relatively low. Coflex and Bacfuse can still be considered better surgical options.

Brown Sequard syndrome in a patient with Klippel-Feil syndrome following minor trauma: a case report and literature review.

BACKGROUND: There are some cases of Klippel-Feil syndrome with spinal cord injury in clinical work. However, there is no literature report on Brown-Sequard syndrome after trauma. We report a case of Brown-Sequard syndrome following minor trauma in a patient with KFS type III. Her Brown-Sequard syndrome is caused by Klippel-Feil syndrome. CASE PRESENTATION: We found a 38-year-old female patient with KFS in our clinical work. She was unconscious on the spot following a minor traumatic episode. After treatment, her whole body was numb and limb activity was limited. Half an hour later, she felt numb and weak in the right limb and weak in the left limb. She had no previous hypertension, diabetes, or coronary heart disease. After one-month treatment of medication, hyperbaric oxygen, rehabilitation, and acupuncture in our hospital, her muscle strength partially recovered, but the treatment effect was still not satisfactory. Then, she underwent surgical treatment and postoperative comprehensive treatment, and rehabilitation training. She was able to take care of herself with assistance, and her condition improved from grade B to grade D according to the ASIA (ASIA Impairment Scale) classification. CONCLUSION: KFS, also known as short neck deformity, is a kind of congenital deformity characterized by impaired formation and faulty segmentation of the cervical spine, often associated with abnormalities of other organs. The cervical deformity in patients with KFS can alter the overall mechanical activity of the spine, as well as the compensatory properties of the spine for decelerating and rotatory forces, thus increasing the chance of spinal cord injury (SCI) following trauma. Many mechanisms can make patients more susceptible to injury. Increased range of motion of the segment adjacent to the fused vertebral body may lead to slippage of the adjacent vertebral body and altered disc stress, as well as cervical instability. SCI can result in complete or incomplete impairment of motor, sensory and autonomic nervous functions below the level of lesion. This woman presented with symptoms of BSS, a rare neurological disorder with incomplete SCI. Judging from the woman's symptoms, we concluded that previously she had KFS, which resulted in SCI without fracture and dislocation following minor trauma, with partial BSS. After the comprehensive treatment of surgery, hyperbaric oxygen, rehabilitation therapy, and neurotrophic drugs, two years later, we found her symptoms significantly improved, with ASIA Impairment Scale from grade B to grade D, and her ability to perform activities of daily living with aids.

Biomechanical comparison of different interspinous process devices in the treatment of lumbar spinal stenosis: a finite element analysis.

BACKGROUND: Lumbar spinal stenosis (LSS) is a common disease among elderly individuals, and surgery is an effective treatment. The development of minimally invasive surgical techniques, such as the lumbar interspinous process device (IPD), has provided patients with more surgical options. OBJECTIVE: To investigate the biomechanical properties of different IPDs, including BacFuse, X-Stop and Coflex, in the treatment of LSS. METHODS: Based on the computed tomography images of a patient with LSS, four finite element (FE) models of L3-S5 were created in this study. The FE models included a surgical model of the intact lumbar spine and surgical models of the lumbar IPDs BacFuse, X-Stop, and Coflex. After validating the models, they were simulated for four physiological motions: flexion, extension, lateral bending and axial rotation, and range of motion (ROM). Stress distribution of discs and facet joints in each segment, stress distribution of the spinous process in the operated section, and stress distribution of the internal fixation were compared and analysed. RESULTS: Compared to the model of the intact lumbar spine, the other three models showed a decrease in ROM and disc and facet joint stresses in the surgical segment during movement and an increase in ROM and disc and facet joint stresses in the adjacent segments. These effects were greater for the proximal adjacent segment with BacFuse and more pronounced for the distal adjacent segment with Coflex, while X-Stop had the greatest stress effect on the spinous process in the surgical segment. CONCLUSION: BacFuse, Coflex and X-Stop could all be implemented to effectively reduce extension and disc and facet joint stresses, but they also increase the ROM and disc and facet joint stresses in adjacent segments, which may cause degeneration.

Oblique lateral interbody fusion combined with different internal fixations for the treatment of degenerative lumbar spine disease: a finite element analysis.

BACKGROUND: Little is known about the biomechanical performance of different internal fixations in oblique lumbar interbody fusion (OLIF). Here, finite element (FE) analysis was used to describe the biomechanics of various internal fixations and compare and explore the stability of each fixation. METHODS: CT scans of a patient with lumbar degenerative disease were performed, and the l3-S1 model was constructed using relevant software. The other five FE models were constructed by simulating the model operation and adding different related implants, including (1) an intact model, (2) a stand-alone (SA) model with no instrument, (3) a unilateral pedicle screw model (UPS), (4) a unilateral pedicle screw contralateral translaminar facet screw model (UPS-CTFS), (5) a bilateral pedicle screw (BPS) model, and (6) a cortical bone trajectory screw model (CBT). Various motion loads were set by FE software to simulate lumbar vertebral activity. The software was also used to extract the range of motion (ROM) of the surgical segment, CAGE and fixation stress in the different models. RESULTS: The SA group had the greatest ROM and CAGE stress. The ROM of the BPS and UPS-CTFS was not significantly different among motion loadings. Compared with the other three models, the BPS model had lower internal fixation stress among loading conditions, and the CBT screw internal fixation had the highest stress among loads. CONCLUSIONS: The BPS model provided the best biomechanical stability for OLIF. The SA model was relatively less stable. The UPS-CTFS group had reduced ROM in the fusion segments, but the stresses on the internal fixation and CAGE were relatively higher in the than in the BPS group; the CBT group had a lower flexion and extension ROM and higher rotation and lateral flexion ROM than the BPS group. The stability of the CBT group was poorer than that of the BPS and LPS-CTFS groups. The CAGE and internal fixation stress was greater in the CBT group.

Overexpression of lncRNA-NEF regulates the miR-155/PTEN axis to inhibit adipogenesis and promote osteogenesis.

Osteoporosis is characterized by osteopenia and bone tissue microstructure degradation. Adipose-derived stem cells (ADSCs) are multipotent adult stem cells that have the ability to yield mesenchymal stem cells and have the potential to undergo osteogenesis and bone regeneration. Therefore, ADSCs have the potential to treat osteoporosis, but the molecular mechanism of these cells in the process of osteogenesis and osteoclasts is still not clear. In the present study, we collected serum samples from 10 clinical osteoporosis patients to detect long noncoding RNA-neighboring enhancer of FOXA2 (lncRNA-NEF) and miR-155 expression levels. Half of these patients were senile and half were postmenopausal women, and nine of them have used steroids for a long time, in which ADSCs were cultured and induced to adipogenic and osteogenic differentiations. Quantitative real-time polymerase chain reaction was used to detect the expression of genes in ADSCs. Overexpression of lncRNA-NEF in ADSCs were undertaken to verify its regulatory function on cell osteogenic and adipogenic differentiations. A luciferase activity experiment was performed to determine the relationship between miR-155 and phosphatase and tensin homologue deleted on chromosome 10 (PTEN). The level of lncRNA-NEF was downregulated, and miR-155 was upregulated, in serum samples from patients with clinical osteoporosis. LncRNA-NEF showed different expression levels in the induction of osteogenic or adipogenic differentiation, which increased during osteogenic induction and decreased during adipogenic induction. Overexpression of lncRNA-NEF or downregulation of miR-155 in ADSCs promoted osteogenic differentiation and inhibited adipogenesis progression. PTEN was the direct target of miR-155 and was involved in the regulation of osteogenic differentiation. Overexpression of lncRNA-NEF regulated the miR-155/PTEN axis to inhibit adipogenesis and promote osteogenesis in ADSCs.

TGF-ß1-containing exosomes derived from bone marrow mesenchymal stem cells promote proliferation, migration and fibrotic activity in rotator cuff tenocytes.

OBJECTIVE: This study aimed to investigate effects of TGF-ß1-containing exosomes derived from bone marrow mesenchymal stem cells (BMSC) on cell function of rotator cuff tenocytes and its implication to rotator cuff tear. METHODS: The primary BMSC and rotator cuff tenocytes were extracted and cultured. Identification of BMSC were performed by observing cell morphology and measurement of surface biomarkers by flow cytometry. BMSC-derived exosomes were extracted and identified by using electron microscopy, nanoparticle-tracking analysis (NTA) and western blotting. Cell proliferation and cell cycle were measured by CCK-8 assay and flow cytometry assay, respectively. Transwell assay was used for detection of tenocytes migration. The fibrotic activity of tenocytes was determined via qPCR and western blotting assays. RESULTS: BMSC and BMSC-derived exosomes were successfully extracted. Treatment of BMSC-derived exosomes or TGF-ß1 promoted cell proliferation, migration and increased cell ratio of (S + G2/M) phases in tenocytes, as well as enhanced the expression levels of fibrotic activity associated proteins. However, inhibition of TGF-ß1 by transfection of sh-TGF-ß1 or treatment of TGFßR I/II inhibitor partially reversed the impact of BMSC-derived exosomes on tenocytes function. CONCLUSION: Taken together, TGF-ß1-containing exosomes derived from BMSC promoted proliferation, migration and fibrotic activity in rotator cuff tenocytes, providing a new direction for treatment of rotator cuff tendon healing.