Segmental Stability Research Articles

Outcome of Long Segment Posterior Spinal Stabilization Incorporating the Fractured Vertebra for Unstable Thoraco-Lumbar Junctional Brust Fracture

Objectives: To evaluate the outcome of long segment posterior spinal stabilization incorporating the fractured vertebra with posterolateral fusion for unstable thoraco-lumbar junctional brust fracture. Background: Thoracolumbar junction is the commonest site of traumatic spinal injury. Now a days, it is managed surgically most of the time because it is often associated with the spinal cord injury. Its mode of surgical management is a field of controversy. Huge debate is still going on between the superiority of long & short segment stabilization. In this study, we evaluated the outcome of long segment posterior spinal stabilization incorporating the fractured vertebra Materials & Method: This prospective interventonal study included 30 case of thoraco-lumbar junctional unstable brust fractures was carried out in the Spine unit of Orthopaedic surgery department of Bangabandhu Sheikh Mujib Medical University, Dhaka and other private hospital in Dhaka City, Bangladesh, from January 2016 to July 2022. All the patients with positive clinical findings, X-ray, MRI & CT scan findings and underwent long segment posterior spinal stabilization incorporating the fractured vertevra with posterolateral fusion. Average follow-up period was 12 months. Pre & Post-operatively, neurological assessment was done by the ASIA Impairment Score, improvement of pain control by VAS score, fusion rate by Bridwell’s criteria, Kyphotic angle was measured by Cobb’s angle measurement method & Overall functional assessment by modified Odom’s score. Results: Total number of patients was 30. Average age was 34 years (range 21- 47). ASIA score improved from B to C in 5 patients, B to D in 5 patients, C to D in 8 patients , C to E in 3 patients, patients, D to E in 7 patients. 2 patient did not improved following surgery. Fusion was achieved in 29 patients & 1 patient developed pseudoarthrosis. Pre & Post- operative VAS score was 7.30±1.9 & 3.3±1.8 respectively. The average kyphotic correction was 15 ∞. In our series, we have no bedridden patients after surgery. There was no radiographic progression after surgery. Conclusion: Early treatment within 21 days of injury with long segment posterior spinal stabilization incorporating the fractured vertevra with posterolateral fusion is a very effective surgical procedure with preservation of the motion segment to treat unstable thoracolumbar junctional brust fracture.

Intraoperative ultrasound guidance assisted oblique lateral interbody fusion for lumbar spinal stenosis

Compared to the posterior lumbar surgery, oblique lumbar interbody fusion (OLIF) can achieve immediate segmental stability and indirect decompression with less blood, less paravertebral muscle injury, and less facet joint violation, which has attracted much attention. However, limitations regarding the decompression efficacy of OLIF exist. Herein, we propose a new hypothesis that direct decompression can be well achieved by the intraoperative ultrasound guidance assisted OLIF (IUG-OLIF). This innovative technology will make it possible to treat serious lumbar spinal stenosis in a very minimally invasive and safe way.

C2 stentoplasty: an alternative to conventional vertebroplasty in the treatment of axis metastatic lesions: a systematic review with meta-analysis and case series.

Vertebroplasty has been recently described in the literature as a potential treatment for C2 metastatic lesions. Stentoplasty may represent a safest and equally alternative to the latter. To describe a novel technique, stentoplasty, as an alternative for the treatment of metastatic involvement of C2 and to assess its efficacy and safety. To systematically evaluate the pertinent literature regarding the clinical outcomes and complications of C2 vertebroplasty in patients with metastatic disease. A systematic review of C2 vertebroplasty, in the English language medical literature was conducted for the needs of this study. Additionally, a cohort of five patients, presenting with cervical instability (SINS > 6) and/or severe pain (VAS > 6) from metastatic involvement of C2 and treated with stentoplasty in our department is presented. Outcomes evaluated include, pain control, stability, and complications. Our systematic review yielded 8 studies that met the inclusion criteria, incorporating 73 patients that underwent C2 vertebroplasty for metastatic disease. There was a reduction in VAS scores following surgery from 7.6 to 2.1. Eleven patients had complications (15%), 3 (4%) required additional stabilization and decompression, 6 (8.2%) had odynophagia and the incidence of cement leak was 31.5% (23/73). With regard to our cohort, all 5 patients presented with severe neck pain (average VAS 6.2 (2-10)) with or without instability (average SINS 10 (6-14)) and underwent C2 stentoplasty. Mean duration of the procedures was 90min (61-145) and 2.6mls (2-3) of cement was injected. Postoperatively VAS improved from 6.2 to 1.6 (P = 0.033). No cement leak or other complications were recorded. A systematic review of the literature demonstrated that C2 vertebroplasty can offer significant pain improvement with a low complication rate. At the same time, this is the first study to describe stentoplasty in a small cohort of patients, as an alternative for the treatment of C2 metastatic lesions in selected cases, offering adequate pain control and improving segmental stability with a high safety profile.

Percutaneous Full Endoscopic Lumbar Discectomy for Symptomatic Adjacent Segment Disease after Lumbar Fusion in Elderly Patients.

Treatment of adjacent segment disease (ASD) is still controversial. The aim of this study was to evaluate the short-term efficacy and safety and to analyze the technical advantages, surgical approach, and indications of percutaneous full endoscopic lumbar discectomy (PELD) in the treatment of ASD after lumbar fusion in elderly patients. A retrospective of 32 patients with symptomatic ASD were accepted for PELD from October 2017 to January 2020. All patients used the transforaminal approach and recorded the operation time and intraoperative conditions. Preoperative, 3, 12, 24 months of postoperative and at the last follow-up, the pain of back and leg of visual analog scale (VAS), Oswestry dysfunction index (ODI), and Japanese Orthopaedic Association Assessment Treatment Score (JOA) were performed, and the paired student's t test was used to the compare the continuous variables preoperatively and postoperatively. The clinical efficacy was evaluated according to MacNab standards. The lumbar MRI was performed to evaluate the decompression of the nerve roots, and the lumbar lateral and dynamic X-rays were performed to evaluate the stability of the surgical segment. A total of 32 patients were included in the study, including 17 males and 15 females. The follow-up time ranged from 24 to 50 months, with an average of (33.2 ± 8.1) months and an average operation time of (62.7 ± 28.1) minutes. Compared to preoperatively, the VAS score of the back and leg pain (p < 0.05), ODI (p < 0.05), and JOA (p < 0.05) postoperatively were significantly improved. At the last follow-up, according to the modified MacNab standard assessment, 24 cases were excellent, five cases were good, and three cases were fair, the excellent and good rate was 90.65%. As for complications, one case had a small rupture of the dural sac during the operation, which was found but not repaired during the operation, and one case recurred after the operation. At the last follow-up, there were three cases of intervertebral instability. PELD showed satisfactory short-term efficacy and safety in the management of ASD after lumbar fusion in elderly patients. Therefore, PELD might be an alternative choice for elderly patients with symptomatic ASD after lumbar fusion, but surgical indications must be strictly controlled.

Full-endoscopic foraminotomy in low-grade degenerative and isthmic spondylolisthesis: a patient-specific tailored approach.

To describe the surgical technique and methodology to successfully plan and execute an endoscopic foraminotomy in patients with isthmic or degenerative spondylolisthesis, according to each patient's unique characteristics. Thirty patients with degenerative or isthmic spondylolisthesis (SL) with radicular symptoms were included from March 2019 to September 2022. Treating physician registered patients' baseline and imaging characteristics, as well as preoperative back pain VAS, leg pain VAS and ODI. Subsequently, authors treated the included patients with an endoscopic foraminotomy according to a "patient-specific" tailored approach. Nineteen patients (63.33%) had isthmic SL and 11 patients (36.67%) had degenerative SL. 75.86% of the cases had a Meyerding Grade 1 listhesis. One of the transforaminal foraminotomies with lateral recess decompression in degenerative SL had to be aborted because of intense osseous bleeding. Of the remaining 29 patients, one patient experienced recurrence of the sciatica pain that required subsequent reintervention and fusion. No other intraoperative or post-operative complications were observed. None of the patients developed post-operative dysesthesia. In 86.67% of the patients, the foraminotomy was implemented using a transforaminal approach. In the remaining 13.33% of the cases, an interlaminar contralateral approach was used. Lateral recess decompression was performed in half of the cases. Mean follow-up time was 12.69months, reaching a maximum of 40months in some patients. Outcome variables such as VAS for leg and back pain, as well as ODI, showed statistically significant reduction since the 3-month follow-up visit. In the presented case series, endoscopic foraminotomy achieved satisfactory outcomes without sacrificing segmental stability. The proposed patient-specific "tailored" approach allowed to successfully design and execute the surgical strategy to perform an endoscopic foraminotomy through transforaminal or interlaminar contralateral approaches.

Molecular simulation studies on a zwitterionic peptide-dendrimer conjugate for integrin αvβ3 binding.

Zwitterionic dendrimer is an effective carrier, which can restore the natural conformation of peptide segments for high bioaffinity by a hydrogen bond-induced conformational constraint approach. However, it is still unknown whether the approach is applicable for the dendrimers with different geometric sizes. Therefore, the characteristics of conjugates made from zwitterionic poly(amidoamine) (PAM) and the arginine-glycine-aspartic acid (RGD) peptide were examined to elucidate the effects of the geometric sizes of the PAM dendrimer on the conformational structure and stability of the peptide. The results show that the RGD fragments had almost the same structure and stability when conjugated with PAM(G3, G4, or G5) dendrimers. However, when conjugated with PAM(G1 or G2) dendrimers, the structural stability of these fragments was found to be much worse. Also, the structure and stability of RGD segments conjugated with PAM(G3, G4, or G5) were not affected when additional EK segments were inserted. Moreover, we observed that RGD fragments conjugated with PAM(G3, G4, or G5) dendrimers were structurally stable and similar when the concentration of NaCl was 0.15 and 0.5M. Furthermore, we show that PAM(G3, G4, or G5)-RGD conjugates bind strongly to integrin αvβ3.

Biomechanical Analysis of Double-Level Oblique Lumbar Fusion with Different Types of Fixation: A Finite Element-Based Study.

One well-liked less invasive procedure is oblique lumbar interbody fusion (OLIF). The biomechanical characteristics of double-level oblique lumbar interbody fusion in conjunction with various internal fixations are poorly understood. The purpose of this study was to clarify the biomechanical characteristics of double-level oblique lumbar interbody fusion for osteoporosis spines using various internal fixation techniques. Based on CT scans of healthy male volunteers, a complete finite element model of osteoporosis in L1-S1 was established. After validation, L3-L5 was selected as the surgical segment to construct four surgical models: (a) two stand-alone cages (SA); (b) two cages with unilateral pedicle screws (UPS); (c) two cages with bilateral pedicle screws (BPS); and (d) two cages with bilateral cortical bone trajectory screws (CBT). Segmental range of motion (ROM), cage stress, and internal fixation stress were studied in all surgical models and compared with the intact osteoporosis model. The SA model had a minimal reduction in all motions. The CBT model had the most noticeable reduction in flexion and extension activities, while the reduction in the BPS model was slightly less than that in the CBT model but larger than that in the UPS model. The BPS model had the greatest limitation in left-right bending and rotation, which was greater than the UPS and CBT models. CBT had the smallest limitation in left-right rotation. The cage stress of the SA model was the highest. The cage stress in the BPS model was the lowest. Compared with the UPS model, the cage stress in the CBT model was larger in terms of flexion and LB and LR but slightly smaller in terms of RB and RR. In the extension, the cage stress in the CBT model is significantly smaller than in the UPS model. The CBT internal fixation was subjected to the highest stress of all motions. The BPS group had the lowest internal fixation stress in all motions. Supplemental internal fixation can improve segmental stability and lessen cage stress in double-level OLIF surgery. In limiting segmental mobility and lowering the stress of cage and internal fixation, BPS outperformed UPS and CBT.

Biportal Endoscopic Transforaminal Lumbar Interbody Fusion Using Double Cages: Surgical Techniques and Treatment Outcomes.

To describe the surgical techniques and the treatment outcomes of biportal endoscopic transforaminal lumbar interbody fusion (BETLIF) using double cages. This study included 89 patients with 114 fusion segments between July 2019 and May 2021. One pure polyetheretherketone (PEEK) cage and 1 composite titanium-PEEK cage were used for interbody fusion. Clinical outcomes measures included visual analogue scale (VAS) scores for lower back pain and leg pain, Oswestry Disability Index (ODI), and Japanese Orthopedic Association (JOA) scores. Computed tomography (CT) of the lumbar spine 1 year postoperatively was used to evaluate the Bridwell interbody fusion grades. There were significant improvement in VAS for lower back pain from 5.2 ± 3.1 to 1.7 ± 2.1, VAS for leg pain from 6.3 ± 2.5 to 1.7 ± 2.0, ODI from 46.7 ± 17.0 to 12.7 ± 16.1, and JOA score from 15.6 ± 6.3 to 26.4 ± 3.2. The p-values were all < 0.001. The average hospital stay was 5.7 ± 1.1 days. The CT studies available for 60 fusion segments showed successful fusion (Bridwell grade I or grade II) in 56 segments (93.3%). Significant cage subsidence of more than 2 mm was only noted in 3 segments (5.0%). Complications included 1 dural tear, 2 pedicle screws malposition, and 2 epidural hematomas, in which 2 patients required reoperations. BETLIF with double cages provided good neural decompression and a sound environment for interbody fusion with a big cage footprint, a large amount of bone graft, endplate preservation, and segmental stability.

Differentiated tactics of surgical treatment of intervertebral disc herniation complicated by spinal canal stenosis

Objective: to conduct a retrospective analysis and evaluate the results of various methods of surgical treatment of patients with intervertebral disc herniation (IDH), which is complicated by spinal canal stenosis (SCS) of the lumbar spine.Materials and methods: 80 patients (36 (45%) men and 44 (55%) women) with a diagnosis of IDH complicated by SCS took part in the study. The average age of patients is under 50 years. All patients were operated on in the neurosurgery department of Zaporizhzhya Regional Clinical Hospital between 2016 and 2020. Patients were divided into two groups depending on the area of ​​the spinal canal and the method of surgical treatment. Group A (n=20) – relative SCS, area of the spinal canal – 75‒100 mm2, the presence of IDH &gt;6 mm (according to magnetic resonance imaging). These patients underwent a standard microdiscectomy. Group B (n=60) ‒ absolute SCS, spinal canal area &lt;75 mm2, the presence of IDH &lt;6 mm (according to magnetic resonance imaging). This category of patients underwent surgery with wide decompression of the spinal canal and stabilization of the spinal motion segment using the method of interbody and transpedicular fixation of the corresponding spinal motion segment. The postoperative follow-up period is up to 6 months. A visual analogue scale was used to assess the pain syndrome in the lower limb and back and the degree of its reduction in the postoperative period. The impact of surgical treatment on the quality of life of patients with IDH complicated by SCS was assessed using the Oswestry Disability Index questionnaire (ODI).Results. Before the operation in group B, an inversely proportional dependence of the pain syndrome level on the visual analogue scale on the age of the patients (p&lt;0.05) and the duration of the disease (p&lt;0.05) was recorded. No such dependence was found in group A. In both groups, a significant decrease in pain syndrome was noted at the end of the first day after surgery, with a further gradual decrease until the end of the observation period. When comparing groups at the end of the first day after surgery, after 3 and 6 months, no statistically significant differences were found (p&gt;0.05). In both groups, a significant decrease in the Oswestry index was registered immediately after surgery and its further decrease until the end of the follow-up period. When comparing the groups at the end of the first day after the operation, after 3 and 6 months, no statistically significant differences were found (p&gt;0.05), but preoperative Oswestry index was significantly higher in group B, (р=0.04 according to the Mann‒Whitney test).Conclusions. In group A, the treatment effectiveness of patients reached 80‒85%, in the observation period on the 3 and 6 months. In group B, the treatment effectiveness of patients was also high and amounted to 75‒80%, in the observation period on the 3 and 6 months. Thus, taking into account the high variability of clinical and morphological changes in patients with IDH complicated by SCS, it is optimal to use differentiated surgical treatment tactics.

Needs and Attitudes of Older Chronic Back Pain Patients towards a Wearable for Ultrasound Biofeedback during Stabilization Exercises: A Qualitative Analysis.

Chronic back pain has a high prevalence, especially in older adults, and seriously affects sufferers' quality of life. Segmental stabilization exercise (SSE) is often used during physiotherapy to enhance core stability. The execution of SSE requires the selective contraction of deep abdominal and back muscles. Motor learning can be supported using ultrasound imaging as visual biofeedback. ULTRAWEAR is a mobile ultrasound system that provides deep learning-based biofeedback on SSE execution, which is currently under development. We interviewed 15 older chronic back pain patients (CBPPs) to investigate their pain management behavior, experience with SSE, as well as their needs and requirements for ULTRAWEAR. We also gathered information about future-usage scenarios. CBPPs reported a high willingness to use the system as a feedback tool both in physiotherapeutic practices and at home. The automated detection and evaluation of muscle contraction states was highlighted as a major benefit of the system compared to the more subjective feedback provided by traditional methods such as palpation. The system to be developed was perceived as a helpful solution to support learning about SSE.

The effect of sagittal alignment, coronal balance, and segmental stability on preoperative patient-reported outcomes in patients with degenerative lumbar spondylolisthesis

ObjectiveThe aim of this study was to investigate the association between spinal alignment and preoperative patient-reported outcomes (PROs) in patients with degenerative lumbar spondylolisthesis (DLS) and to identify the independent risk factors for worse preoperative PROs.MethodsIn total, 101 patients suffering from DLS were retrospectively studied within a single medical center. Age, sex, height, weight, and body mass index were uniformly recorded. PRO-related indicators include the Oswestry Disability Index (ODI), the Japanese Orthopedic Association’s (JOA) score, and the visual analog scale (VAS) for back and leg pain. Sagittal alignment, coronal balance, and stability of the L4/5 level were evaluated through whole-spine anteroposterior and lateral radiographs and dynamic lumbar X-ray.ResultsIncreasing age (P = 0.005), higher sagittal vertical axis (SVA) (P < 0.001), and global coronal imbalance (GCI) (P = 0.023) were independent risk factors for higher ODI. Patients with GCI had lower JOA scores (P = 0.001) than those with balanced coronal alignment. Unstable spondylolisthesis (P < 0.001) and GCI (P = 0.009) were two vital predictors of VAS-back pain. Increasing age (P = 0.031), local coronal imbalance (LCI) (P < 0.001), and GCI (P < 0.001) were associated with higher VAS-leg pain. Moreover, patients with coronal imbalance also exhibited significant sagittal malalignment based on the subgroup analysis.ConclusionDLS patients with higher SVA, unstable spondylolistheses, a combination of LCI/GCI, or increasing age were predisposed to have more severe subjective symptoms before surgery.

Biomechanical evaluation of Percutaneous endoscopic posterior lumbar interbody fusion and minimally invasive transforaminal lumbar interbody fusion: a biomechanical analysis

In order to analyze and evaluate the stability of lumbar spine and the risk of cage subsidence after different minimally invasive fusion operations, two finite element models Percutaneous endoscopic posterior lumbar interbody fusion (PE-PLIF) and minimally invasive transforaminal lumbar interbody Fusion (MIS-TLIF) were established. The results showed that compared with MIS-TLIF, PE-PLIF had better segmental stability, lower pedicle screw rod system stress, and lower risk of cage subsidence. The results suggest that the cage with appropriate height should be selected to ensure the segmental stability and avoid the risk of the subsidence caused by the cage with large height.

Biomechanical Evaluation of Rigid Interspinous Process Fixation Combined With Lumbar Interbody Fusion Using Hybrid Testing Protocol.

Rigid interspinous process fixation (RIPF) has been recently discussed as an alternative to pedicle screw fixation (PSF) for reducing trauma in lumbar interbody fusion (LIF) surgery. This study aimed to investigate biomechanics of the lumbar spine with RIPF, and also to compare biomechanical differences between two postoperative stages (before and after bony fusion). Based on an intact finite-element model of lumbosacral spine, the models of single-level LIF with RIPF or conventional PSF were developed and were computed for biomechanical responses to the moments of four physiological motions using hybrid testing protocol. It was found that compared with PSF, range of motion (ROM), intradiscal pressure (IDP), and facet joint forces (FJF) at adjacent segments of the surgical level for RIPF were decreased by up to 8.4%, 2.3%, and 16.8%, respectively, but ROM and endplate stress at the surgical segment were increased by up to 285.3% and 174.3%, respectively. The results of comparison between lumbar spine with RIPF before and after bony fusion showed that ROM and endplate stress at the surgical segment were decreased by up to 62.6% and 40.4%, respectively, when achieved to bony fusion. These findings suggest that lumbar spine with RIPF as compared to PSF has potential to decrease the risk of adjacent segment degeneration but might have lower stability of surgical segment and an increased risk of cage subsidence; When achieved bony fusion, it might be helpful for the lumbar spine with RIPF in increasing stability of surgical segment and reducing failure of bone contact with cage.

Diffuse idiopathic skeletal hyperostosis: A functional enemy of vertebral stability - Case series and surgical consideration of craniovertebral junction involvement.

Diffuse idiopathic skeletal hyperostosis (DISH) or Forestier's syndrome may reduce vertebral mobility, thus affecting the stability of adjacent vertebral segments and promoting spinal stenosis, vertebral dislocation, and unstable fracture secondary to low-energy trauma. This study aimed to contribute with a case series of three patients affected by DISH undergone surgery with occipitocervical fixation for craniovertebral junction (CVJ) instability since the poor literature about CVJ instability and surgery in patients affected by DISH. This was a multicentric case series. Literature about CVJ instability and surgery in patients affected by DISH is poor. Thus, we present a case series of three patients affected by DISH, who underwent surgery with occipitocervical fixation with different clinical and radiological patterns. CVJ represents one of the most mobile joints of the spine and is at greater risk for instability. Moreover, instability itself may act as primum movens for several degenerative conditions such as cervical spondylosis, ossification of the posterior longitudinal ligament, and cervical deformities. On the contrary, DISH itself may worsen CVJ instability because of subaxial spine stiffness. In case of DISH, the rigid unit formed by several ossified vertebral bodies acts as a long lever arm, increasing the forces applied to the hypermobile CVJ and reducing the dynamic buffer capability of ossified spine. On the other hand, vertebral instability increases the odds of fractures. In such cases, CVJ posterior instrumentation and fusion is an effective and feasible surgical technique, aimed to restore vertebral stability and to halt the progression of spinal stenosis. Due to the altered dynamics cervical spine along with the possible comorbidities, treatment indication and surgery for patients affected by DISH must be tailored case by case.

Paraspinal muscles atrophy on both sides and at multiple levels after unilateral lumbar partial discectomy.

To identify the changes in cross-sectional areas (CSAs) and fatty infiltration of both sides of the paravertebral muscles and their associations with prognostic factors in patients who underwent unilateral lumbar discectomy. We retrospectively reviewed 27 patients who underwent magnetic resonance imaging before and after 1- or 2-level lumbar discectomy. The CSAs and functional cross-sectional areas of the paraspinal muscles were bilaterally measured from L1 to L2 to L5 to S1 based on T2-weighted axial images. These parameters were compared pre-and postoperatively. CSAs and functional cross-sectional areas decreased also in non-operative, non-surgical levels, not only in operated levels after discectomy. In the correlation analysis, the CSA of psoas major muscle at L1 to L2 was significantly decreased in patients with lower preoperative lordosis (r = 0.598, P = .040). The postoperative CSA of psoas major muscle at L4 to L5 was lower in those with the higher Pfirrmann grade (r = -0.590, P = .002); however, the CSA of quadratus lumborum muscle at L1 to L2 showed the opposite result (r = 0.526, P = .036). Similar results were also observed in the partial correlation adjusted for age and postoperative duration. Patients who underwent discectomy experienced overall paraspinal muscle atrophy in the lumbar region, including surgical and non-surgical sites. Such atrophic changes emphasized the need for core strengthening and lumbar rehabilitation from the early period after partial discectomy.

Three-Dimensional Accuracy and Stability of Personalized Implants in Orthognathic Surgery: A Systematic Review and a Meta-Analysis.

This systematic review aimed to determine the accuracy/stability of patient-specific osteosynthesis (PSI) in orthognathic surgery according to three-dimensional (3D) outcome analysis and in comparison to conventional osteosynthesis and computer-aided designed and manufactured (CAD/CAM) splints or wafers. The PRISMA guidelines were followed and six academic databases and Google Scholar were searched. Records reporting 3D accuracy/stability measurements of bony segments fixated with PSI were included. Of 485 initial records, 21 met the eligibility (566 subjects), nine of which also qualified for a meta-analysis (164 subjects). Six studies had a high risk of bias (29%), and the rest were of low or moderate risk. Procedures comprised either single-piece or segmental Le Fort I and/or mandibular osteotomy and/or genioplasty. A stratified meta-analysis including 115 subjects with single-piece Le Fort I PSI showed that the largest absolute mean deviations were 0.5 mm antero-posteriorly and 0.65° in pitch. PSIs were up to 0.85 mm and 2.35° more accurate than conventional osteosynthesis with CAD/CAM splint or wafer (p &lt; 0.0001). However, the clinical relevance of the improved accuracy has not been shown. The literature on PSI for multi-piece Le Fort I, mandibular osteotomies and genioplasty procedure is characterized by high methodological heterogeneity and a lack of randomized controlled trials. The literature is lacking on the 3D stability of bony segments fixated with PSI.

Computational comparison of anterior lumbar interbody fusion and oblique lumbar interbody fusion with various supplementary fixation systems: a finite element analysis

Background and objectiveAnterior lumbar interbody fusion (ALIF) and oblique lumbar interbody fusion (OLIF) have shown a great surgical potential, while it has always been controversial which surgical approach and which type of fixation system should be selected. This study investigated the biomechanical response of ALIF and OLIF with various supplementary fixation systems using the finite element method.Materials and methodsLumbar L4–L5 ALIF and OLIF models stabilized by different supplementary fixation systems (stand-alone cage, integrated stand-alone cage, anterior plate, and bilateral pedicle screw) were developed to assess the segmental range of motion (ROM), endplate stress (EPS), and screw-bone interface stress (SBIS).Experimental resultsALIF showed lower ROM and EPS than OLIF in all motion planes and less SBIS in the most of motion planes compared with OLIF when the anterior plate or pedicle screw was used. ALIF induced higher ROM, while lower EPS and SBIS than OLIF in the majority of motion planes when integrated stand-alone cage was utilized. Using a stand-alone cage in ALIF and OLIF led to cage migration. Integrated stand-alone cage prevented the cage migration, whereas caused significantly larger ROM, EPS, and SBIS than other fixation systems except for the rotation plane. In the most of motion planes, the pedicle screw had the lowest ROM, EPS, and SBIS. The anterior plate induced a slightly larger ROM, EPS, and SBIS than the pedicle screw, while the differences were not significant.ConclusionALIF exhibited a better performance in postoperative segmental stability, endplate stress, and screw-bone interface stress than OLIF when the anterior plate or the pedicle screw was used. The pedicle screw could provide the greatest postoperative segmental stability, less cage subsidence incidence, and lower risk of fixation system loosening in ALIF and OLIF. The anterior plate could also contribute to the stability required and fewer complications, while not as effectively as the pedicle screw. Extreme caution should be regarded when the stand-alone cage is used due to the risk of cage migration. The integrated stand-alone cage may be an alternative method; however, further optimization is needed to reduce complications and improve postoperative segmental stability.

"Insert flipping technique:" An effective way of restoring segmental lordosis and disc height with tall bullet cages.

The study design was a retrospective study. The objectives of the present study are dual; to describe a simple and effective way of restoring intervertebral disc (IVD) height by the "Insert Flip Technique" of cage insertion and to demonstrate effective restoration of IVD height and segmental lordosis (SL) and their influence on the functional outcome postoperatively. IVD height and SL were recorded pre- and postoperatively. Each motion segment was instrumented with pedicle screws to allow segmental stabilization. Patients were called for follow-up at 6 weeks, 3 months, and 1 year postoperatively and were assessed clinically for back pain and leg pain (VAS and Oswestry Disability Index scores recorded).The bullet cages are designed such that they are lordotic in the superior-inferior plane and neutral in the mediolateral plane. Usually, the cage is inserted with superior and inferior surfaces of the cage impacting against superior and inferior end plates of the adjacent vertebral body. However, with the proposed technique, the cages were inserted such that the narrower mediolateral surfaces of the cage engaged with superior and inferior vertebral end plates. The cage was then flipped within the disc space such that the superior-inferior surfaces of the bullet cage impacted against the superior and inferior end plates of the vertebral body to create desired lordosis. There was a significant improvement seen in the postoperative Cobb's angle and disc height after placement of a tall bullet cage compared to the preoperative Cobb's angle and disc height. This modification of technique helped in gaining lordosis with taller bullet cages in minimally invasive surgery transforaminal lumbar interbody fusion with no/minimal complication and also reduced the need for bone resection during insertion of the cage.

Spinal anesthesia efficiency in thoracolumbar stabilizations.

<p>Spinal surgery has an important place in neurosurgery practice. Surgical procedures on the lumbar spine include stabilization, discectomy, foraminotomy and decompression. Lumbar and lower thoracic spinal surgery can be safely performed under spinal anesthesia (SA). However, there are not many studies on the safety and efficacy of spinal anesthesia in patients who have undergone long segment stabilization surgery.<br><br></p>. <p>Patients who underwent lumbar and lower thoracic spinal instrumentation operations with general anesthesia (GA) or spinal anesthesia were included in the study. Demographic characteristics and American Society of Anesthesiologists (ASA) physical status of the patients were all recorded. Visual analog scale and quality of life scores were obtained before and after the operation.</p>. <p>572 patients with SA and 598 patients with GA were included in the study, 352 / 347 had only-lumbar region and 220 / 251 had thoracolumbar region operations, respectively. All patients underwent short/long segment stabilization. Mean operating time was 106.1 / 156.7 minutes. Average blood loss was 375 / 390 mL. All patients were mobilized 16-24 / 24-36 hours after surgery. In our patient group, there were both high-risk and normal-risk subgroups in terms of ASA physical status. During the clinical follow-up, a statistically significant improvement was found for VAS and quality of life scores for both groups (p&lt;0.05).</p>. <p>Spinal anesthesia appears to be a very effective method in lumbar and thoracolumbar surgery. Along with careful patient selection, using this highly effective method provides a comfortable space for the surgeon.</p>.

The Segmentation of Mobile Application Users in The Hotel Booking Journey

Aim/Purpose: This study aims to create customer segmentation who use Online Travel Agent (OTA) mobile applications in Indonesia throughout their hotel booking journey. Background: In the context of mobile hotel booking applications, research analyzing the customer experience at each customer journey stage is scarce. However, literature increasingly acknowledges the significance of this stage in comprehending customer behavior and revenue streams. Methodology: This study employs a mixed-method and exploratory approach by doing in-depth interviews with 20 participants and questionnaires from 207 participants. Interview data are analyzed using thematic analysis, while the questionnaires are analyzed using descriptive statistics. Contribution: This study enriches knowledge in understanding customer behavior that considers the usage of mobile apps as a segmentation criterion in the hotel booking journey. Findings: We developed four user personas (no sweat player, spotless seeker, social squad, and bargain hunter) that show customer segmentation based on the purpose, motivation, and actions in each journey stage (inspiration, consideration, reservation, and experience). Recommendations for Practitioners: The resulting customer segmentation enables hospitality firms to improve their current services by adapting to the needs of various segments and avoiding unanticipated customer pain points, such as incomplete information, price changes, no social proof, and limited payment options. Recommendation for Researchers: The quality and robustness of the customer segment produced in this study can be further tested based on the criteria of homogeneity, size, potential benefits, segment stability, segment accessibility, segment compatibility, and segment actionability. Impact on Society: This study has enriched the existing literature by establishing a correlation between user characteristics and how they use smartphones for tourism planning, focusing on hotel booking in mobile applications. Future Research: For future research, each customer segment’s demographic and behavioral factors can be explored further.