Short Fusion Research Articles

Engineering a Silk Protein-Mediated Customizable Compartment for Modular Metabolic Synthesis.

Microbial cell factories provide a nontoxic, economical way for the synthesis of various chemicals and drugs, garnering significant attention from researchers. However, excessive dispersion of enzymes and accumulation of intermediate metabolites in the production process will weaken the reaction efficiency of the pathway enzyme. In this study, a cellular compartment was constructed to isolate the enzyme reaction space and optimize the modular metabolic synthesis. First, a special spider silk protein was designed and constructed to form protein condensates in microbial cells, and its synthetic microcompartment effects were investigated. Second, the interaction of short peptide pairs or direct fusion based on the silk protein was used to recruit a variety of enzymes to improve the efficiency of enzyme catalysis. Third, the 2'-fucosyllactose (2'-FL) de novo synthesis pathway and its modular optimization were carried out to verify the mode. Finally, a synthetic compartment was introduced into the pathway to directly aggregate the 2'-FL synthesis pathway, thus obtaining synthetic-compartment-mediated multienzyme aggregates. The experimental results showed that the titer of 2'-FL was significantly improved compared with those of wild-type and modular-optimized free enzymes. The utilization of this cell microcompartment offers a novel avenue for the aggregation of diverse enzymes, thereby offering an innovative approach for enhancing the efficiency of the microbial modular metabolic pathway.

Defining modern iatrogenic flatback syndrome: examination of segmental lordosis in short lumbar fusion patients undergoing thoracolumbar deformity correction.

Understanding the mechanism and extent of preoperative deformity in revision procedures may provide data to prevent future failures in lumbar spinal fusion patients. ASD patients without prior spine surgery (PRIMARY) and with prior short (SHORT) and long (LONG) fusions were included. SHORT patients were stratified into modes of failure: implant, junctional, malalignment, and neurologic. Baseline demographics, spinopelvic alignment, offset from alignment targets, and patient-reported outcome measures (PROMs) were compared across PRIMARY and SHORT cohorts. Segmental lordosis analyses, assessing under-, match, or over-correction to segmental and global lordosis targets, were performed by SRS-Schwab coronal curve type and construct length. Among 785 patients, 430 (55%) were PRIMARY and 355 (45%) were revisions. Revision procedures included 181 (23%) LONG and 174 (22%) SHORT corrections. SHORT modes of failure included 27% implant, 40% junctional, 73% malalignment, and/or 28% neurologic. SHORT patients were older, frailer, and had worse baseline deformity (PT, PI-LL, SVA) and PROMs (NRS, ODI, VR-12, SRS-22) compared to primary patients (p < 0.001). Segmental lordosis analysis identified 93%, 88%, and 62% undercorrected patients at LL, L1-L4, and L4-S1, respectively. SHORT patients more often underwent 3-column osteotomies (30% vs. 12%, p < 0.001) and had higher ISSG Surgical Invasiveness Score (87.8 vs. 78.3, p = 0.006). Nearly half of adult spinal deformity surgeries were revision fusions. Revision short fusions were associated with sagittal malalignment, often due to undercorrection of segmental lordosis goals, and frequently required more invasive procedures. Further initiatives to optimize alignment in lumbar fusions are needed to avoid costly and invasive deformity corrections. IV: Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

Long-term results of single-stage posterior hemivertebra resection and short segment fusion using pedicle screws fixation in thoracolumbar congenital early-onset scoliosis: an 8.97-year average follow-up study

BackgroundThis study aims to evaluate the long-term outcomes of one-stage posterior hemivertebra resection and short segment fusion with pedicle screw fixation in children with thoracolumbar congenital early-onset scoliosis (TLCEOS). It specifically investigates the durability of spinal correction and the incidence of complications over an average follow-up of 8.97 years.MethodsA retrospective review was conducted on 32 patients treated at a tertiary scoliosis referral center from April 2003 to December 2019. Inclusion criteria were thoracolumbar hemivertebra (T11-L1), treatment via posterior hemivertebra resection and short segment fusion (≤ 5 segments), age under 10 years at surgery, and a follow-up of at least 5 years. Exclusions included idiopathic, syndromic, or neuromuscular scoliosis. Data on demographics, surgical procedures, and radiographic outcomes were collected, and clinical outcomes were evaluated using the Scoliosis Research Society-22 (SRS-22) questionnaire. Statistical analysis was performed using SPSS and R software.ResultsThe study included 32 patients (22 males, 10 females) with a mean age of 5.00 ± 2.42 years at surgery and an average follow-up of 8.97 ± 2.81 years. On average, 3.47 ± 1.11 segments were fused. The main curve corrected from 38.64° ± 14.12° preoperatively to 9.06° ± 7.29° postoperatively, with a final correction rate of 61%. Significant improvements were observed in the SRS-22 domains of Appearance and Satisfaction with Treatment. There were 17 complications, including neurological, pulmonary, and mechanical issues, with some cases requiring revision surgery.ConclusionsOne-stage posterior hemivertebra resection and short segment fusion with pedicle screw fixation effectively correct TLCEOS long-term, offering significant improvements in patient appearance and satisfaction, with a manageable complication profile.

Classification of Emerging Scoliosis in Congenital Scoliosis After Hemivertebra Resection and Short Segmental Fusion.

Emerging scoliosis (ES) is a rare phenomenon after hemivertebra (HV) resection and short segmental fusion. Since the introduction of the ES, there have been rare in-depth studies. The aim of the present study was to further analyze the characteristics, risk factors, treatment, and prognosis of ES. A retrospective study analyzed patients with congenital scoliosis due to a single HV who underwent posterior correction and short fusion from 2002 to 2022. ES was defined as a Cobb angle ≥20° from its initial value and an apical vertebra located ≥2 levels away from the fusion region. ES patients and non-ES patients were matched at a 1:2 ratio. Both demographics and radiological parameters were compared. Univariate analysis and multivariate logistic analysis were used to identify the risk factors of ES. Among 261 patients, 13 patients (5.0%) experienced ES. There were eight females and five males. The mean age of the ES patients at the time of primary surgery was 6.6 ± 3.7 years old (2.0-13.2 years old), with a mean follow-up of 64.2 ± 47.9 months (12-156 months). The ES could be further divided into three types: balance-related ES, complication-related ES, and separated ES. There were three balance-related ESs, six complication-related ESs, and four separated ESs. At the last follow-up, six patients were under observation, six patients underwent brace treatment, and one patient underwent revision surgery. Multivariate logistic analysis showed that the magnitude of postoperative compensatory curve (CC) was an independent risk factor for ES (OR = 1.172, p = 0.014). ES is an extraordinary phenomenon after HV resection and short fusion, and it can be divided into three types. The magnitude of postoperative CC was an independent risk factor for ES. According to the severity of ES, observation, brace, or surgery can be chosen.

Outcome of Short Segment Fixation for Degenerative Scoliosis in Osteoporotic Patients Using Augmented Pedicle Screws; Prospective Case Series Study

Abstract Background When a patient’s general condition is taken into account, long-segment fusion may not necessarily be the best approach for degenerative scoliosis management. Often, a patient’s symptoms may be alleviated by short segment decompression and fusion surgery that is limited to the upper and lower vertebral boundaries of the scoliotic region. In osteoporotic patients studies reported good functional outcomes and very low revision rates with polymethylmethacrylate augmented screws. Aim of the Work This study aims to evaluate the clinical and radiological outcomes of short segment fixation for degenerative scoliosis in osteoporotic patients using augmented screws. Patients and Methods This is a prospective Case series study carried out at Ain Shams University hospitals which included 23 patients resistant back pain and lower limb claudication pain not relieved by medical treatment or physical therapy for at least 6 months. All cases managed with Posterior decompression and short segment fixation using pedicle screws augmented with cement (PMMA). Results As regards the VAS for leg pain, it showed improvement from 7.18 (± 0.07) to 1.91 (± 0.14). The VAS for back pain also improved from preoperatively 8.17 (± 0.11) to postoperatively 2.52 (± 0.24). As regards the ODI score, there was a significant decrease in the ODI scores from pre-surgery 68.09 (± 1.13) to 12 months post-surgery 25.57 (± 2.02). The Cobb angle decreased dramatically from pre-operative 15.9 (± 0.57) to post- operative, and then increased slightly but remained stable at 6 and 12 months with mean value at last follow up 4.85 (± 0.45). We did not have nonunion cases but only 3 delayed union cases at 6 months and was full united at 12 months that assessed by continuity of osseous bridging between transverse processes in plain X rays and CT scan. compared to similar published literatures This study technique has average blood loss, operation time and hospital stay and decrease the need for revision surgery but with increased hazards of high intraoperative radiation exposure. Conclusion Short segment fixation using augmented screws showed a very good clinical outcome in management of degenerative scoliosis with osteoporosis as regards VAS for back pain, VAS for leg pain and ODI score. According to radiological parameters it showed a good result in cobb angle correction, fusion rate, screws and construct stability after 1 year follow up, less pedicle screw loosening and less rate of revision surgery.

Impact of Segmental Lordosis Restoration During Degenerative Spinal Fusion on Two-Year Adjacent Segment Disease and Revision Rates.

Retrospective cohort study. Assess the impact of inadequate correction of L4-S1 lordosis during transforaminal lumber interbody fusion (TLIF) on adjacent segment disease and revision rates. Restoring alignment is an important consideration in spinal fusions. Failure to correct to level-specific alignment goals could promote the development of adjacent segment disease. As such, it is crucial to investigate the role of sagittal segmental alignment on clinical outcomes following short segment lumbar fusion. Patients who underwent 1- to 3-level transforaminal lumbar interbody fusion (TLIF) and had two-year outcomes data were included in this retrospective cohort study. Segmental lumbar lordosis was assessed in all patients with L3-L4, L4-L5, and L5-S1 constructs. Demographics, radiographic spinopelvic alignment, and complications were compared in a sub-group of patients fused at L4-S1 with adequate (i.e., within 35-45°) and inadequate (i.e., <35°) L4-S1 lordosis. Among the 168 included patients, mean age was 61.7 years, 56.0% were female, and mean follow-up was 32.3 months. Segmental lumbar lordosis did not change significantly after TLIF of L3-L4, L4-L5, or L5-S1 (P>0.05). Two-year postoperatively, 32.7% developed adjacent segment disease and 19.6% underwent revisions. After stratification by adequate (N=15) or inadequate (N=54) restoration of L4-S1 lordosis following initial TLIF surgery, adequately-restored patients had higher preoperative L4-S1 lordosis (Adequately-Restored=39.3° vs Inadequately-Restored=29.5°, P<0.001) and lower two-year postoperative adjacent segment disease (6.7% vs. 33.3%, P=0.032) and revision (5.7% vs. 25.9%, P=0.l33) rates. Adjacent segment disease patients had higher implant-related complications (Adjacent Segment Disease=36.8% vs No Adjacent Segment Disease=8.0%, P=0.008) and subsequent revisions (61.1% vs. 8.7%, P<0.001). Adjacent segment disease and revisions after degenerative lumbar spinal fusion are common. In this cohort, suboptimal restoration of L4-S1 lordosis was associated with higher rates of adjacent segment disease and subsequent revisions, thus highlighting the importance of restoring sagittal alignment in degenerative spine surgery. III.

Comparative analysis of early versus late surgical intervention for lumbosacral hemivertebra: a minimum 2-year follow-up retrospective study

BACKGROUND CONTEXTLumbosacral hemivertebra (LSHV) is a complex and unique congenital spinal deformity characterized by early severe trunk imbalance and progressive compensatory curve. Previous studies have proved the efficiency of posterior LSHV resection. However, the optimal timing for surgical intervention of LSHV still remains controversial. Few studies compare the surgical outcomes in patients of different age groups. PURPOSETo evaluate the influence of posterior-only LSHV resection surgery timing on clinical and radiographic results. STUDY DESIGNRetrospective analysis. PATIENT SAMPLEWe retrospectively analyzed 58 LSHV patients undergoing posterior-only LSHV resection with short-segment fusion at our institution between 2010 and 2020, with a mean follow-up of 7.5 years. OUTCOME MEASUREThe following data were observed for all cases: patient demographics, clinical outcomes measured by operating time, intraoperative blood loss, complications, and Health-Related Quality of Life, radiographic parameters included Cobb angles, trunk shift and sagittal spinal parameters. METHODSFrom 2010 to 2020, a consecutive series of 58 LSHV patients treated by posterior LSHV resection with short segmental fusion were investigated retrospectively, with a 7.5-year average follow-up period. Patients were stratified into 2 groups based on the timing of surgery: Group E (≤6 years old, representing the early-surgery) and Group L (>6 years old, representing the late-surgery). Radiographic assessments included pre- and postoperative measurements of main scoliosis, compensatory scoliosis, trunk shift, and sagittal balance parameters. Operative data, perioperative complications and SRS-22 questionnaires were also collected. RESULTSCompared to Group L, Group E exhibited a lower intraoperative blood loss (p<.001), higher final main curve correction rate (p=.037), smaller post-op compensatory curve (p=.031), higher sagittal vertical axis correction rates at immediate post-op (p=.045) and last follow-up (p=.027), and lower implant failure complications incidence (p=.006). CONCLUSIONThis study suggested that early surgical intervention in LSHV patients can achieve better correction outcomes, while reducing blood loss and postoperative complications in a large-scale cohort.

Lateral Anterior Column Release in Short Lumbar Fusion… Is It Worth It?

Radiographic adjacent segment disease (ASD) ranges from 10% to 84%, depending on technique. Occurrence of symptomatic ASD is lower, with a range of 1.9% to 13%. ASD can be very debilitating and necessitate further procedures, leading to high morbidity. Herein, we explore the occurrence of adjacent segment disease when performing anterior column release in lateral interbody fusion. After institutional review board approval, 120 total patients who underwent lateral lumbar interbody fusion (LLIF) at our facility from 2013 to 2020 were retrospectively reviewed, allowing for a minimum of 3years for follow-up time. Surgical variables and spinopelvic parameters were measured and collected by our team. Statistical measures of significance were calculated using IBM SPSS Statistics Version29. One hundred twenty total patients were included. 73.3% of patients had percutaneous screws, and 11.7% had open. Thirteen patients underwent LLIF with anterior column release (ACR). The mean lumbar lordosis (LL) was 50.1±12.9, pelvic incidence (PI) was 52.8±11.2, sacral slope was 33.6±9.2, pelvic tilt was 18.1±6.8, and sagittal vertical axis was 6.8mm±30.5.Twenty four total patients had ASD after LLIF. In univariable analysis, ACR (P < 0.001) and PI-LL Mismatch (P < 0.035) were risk factors for developing ASD. In multivariable analysis, greater PI-LL mismatch was predictive of ASD (P < 0.005, OR=1.097, and 95% confidence interval=1.029-1.171), as was ACR (P < 0.001, OR=9.667, and 95% confidence interval=2.669-35.09). Higher PI-LL mismatch after lumbar interbody fusion, and performance of an ACR during LLIF increased the likelihood of developing symptomatic ASD in our patients. Considering ACR to achieve the goal of correcting spinopelvic parameters should be carefully evaluated when undertaking a lateral approach.

Posterior-only approach cervical hemivertebrectomy and short fusion with pedicle screws in young children with cervical scoliosis: case report and technical note.

Cervical hemivertebrae (C3-6) causing significant osseous torticollis, head tilt and facial asymmetry are rare and complicated. Cervical hemivertebrectomy (CHVE) by a posterior-only approach was never reported because it is highly risky and its efficacy remains controversial. This study is to evaluate the feasibility and preliminary clinical outcomes of posterior-only approach for CHVE and torticollis correction in young children. Four young children aged 5-9 years old with significant torticollis caused by cervical hemivertebrae underwent deformity correction consisting of cervical pedicle screw (CPS) placement with O-arm-based intraoperative navigation, CHVE using ultrasonic bone scalpel and short-segmental posterior instrumentation and fusion. Details of this novel technique were presented. The preliminary short-term clinical and radiographic outcomes were assessed. On average, the operative time was 312.5 ± 49.9min, and the surgical blood loss was 375.0 ± 150.0ml. The structural cervical scoliosis was corrected from 31.5 ± 7.3° to 11.0 ± 4.1°, and the average correction rate was 64.9%. Head tilt was favorably corrected from 11.0 ± 4.2° to 3.5 ± 2.6°. The shoulder balance improved from 6.3 ± 1.3° to 1.5 ± 1.9°. One case with C6 CHVE had convex side radiating nerve root pain but no sign of muscle power weakness. Full recovery was achieved one month after surgery. No other complication occurred. CHVE by a posterior-only approach was a feasible alternative option for the treatment of congenital cervical scoliosis. It could resect the CHV effectively and achieve satisfactory torticollis correction without additional anterior access surgery. Successful CPS placement in this child population was essentially important to enable reliable osteotomy closure and firm posterior instrumentation.

P159. Presence of compensatory curve predicts postoperative curve progression in congenital scoliosis after thoracolumbar hemivertebra resection and short fusion

P159. Presence of compensatory curve predicts postoperative curve progression in congenital scoliosis after thoracolumbar hemivertebra resection and short fusion

Evaluation of the efficacy of posterior hemivertebrectomy combined with two or more segments fusion

BackgroundAlthough early hemivertebra (HV) resection and short fusion (within 4 segments) have been successful in treating congenital HV, there is limited research comparing the outcomes of the shortest-segment fusion (2 segments) versus 3 or 4 segments, particularly in young children. To evaluate the efficacy of posterior hemivertebrectomy combined with two or more segments fusion in children under the age of 10 years with a solitary simple lower thoracic or lumbar HV (T8-L5).MethodsThis retrospective study included patients under the age of 10 with lower thoracic or lumbar solitary simple HV who underwent hemivertebra resection (HVR) and transpedicular short fusion and were divided into HV ± 1 group (2 segment fusion) and HV ± 2 group (3 or 4-segment fusion). The study recorded preoperative, postoperative (1 week), and the latest follow-up radiographic parameters and complications. The results of the coronal and sagittal planes were analyzed, and the main curve, segmental scoliosis curve, compensatory scoliosis curve, segmental kyphosis curve, and trunk shift were compared.ResultsThe study included 35 patients (15 in the HV ± 1 group and 20 in the HV ± 2 group) with a mean age of 5.26 ± 2.31 years and a mean follow-up of 22.54 months (12–68). The mean preoperative Cobb angle was 32.66° ± 7.339° (HV ± 1) and 29.31°±6.642° (HV ± 2). The final Cobb angle was 10.99°± 7.837° (HV ± 1) and 8.22° ± 4.295° (HV ± 2). The main curve corrected by 72% (HV ± 1), 75% (HV ± 2) postoperatively and 67% (HV ± 1), 72% (HV ± 2) at the final follow-up (P > 0.05). There were no significant differences in the correction of the segmental scoliosis curve, compensatory scoliosis curve, segmental kyphosis curve, and trunk shift between the HV ± 1 and HV ± 2 groups (P > 0.05). The unplanned reoperation rate for HV in the thoracolumbar region (T11-L2) is significantly higher (P = 0.038).ConclusionIn the context of solitary simple lower thoracic or lumbar HV (T8-L5), HV ± 1 segment fusion suffices and yields comparable correction outcomes in the midterm period when compared to HV ± 2. The reoperation rate exhibited a statistically significant increase in the thoracolumbar region.

Complications and health-related quality of life following lumbosacral hemivertebra resection and short segmental fusion: a retrospective cohort study

Previous literature has provided descriptions of postoperative complications. However, these studies have included heterogeneous cohorts of hemivertebra patients undergoing different surgical methods and addressing deformities at various locations. To assess independent risk factors for complications following lumbosacral hemivertebra (LSHV) resection and to further explored the potential association between complications and health-related quality of life (HRQOL). Retrospective cohort study. We retrospectively analyzed consecutive patients who underwent LSHV resection and short segment fusion at our institution between 2010 and 2022. In the current study, the outcome measure were complications and HRQOL. Between 2010 and 2022, a total of 64 consecutive patients with LSHV underwent hemivertebra resection. The diagnostic criteria for LSHV were delineated that the hemivertebra resides caudal to L5 and beyond. Electronic patient record and radiographic data were reviewed retrospectively in our electronic database. According to complications, the patients were divided into with and without complications, and further stratified as neurological, mechanical, and infectious complications. HRQOL outcomes were collected preoperatively, 3 months postoperatively, and at last follow-up using the Scoliosis Research Society-22 (SRS-22) questionnaire. Multivariate logistic regression models were used to determine independent risk factors affecting complications. A total of 64 patients were enrolled in this study for at least 2-year follow-up. The mean follow-up was 7.3±4.2 years. In the coronal plane, the mean main curve was corrected from 27.3° preoperatively to 8.0° postoperatively, and 9.3° at last follow-up. Global spine balance was significantly improved after surgery, and kept stable during the follow-up. In all, 18 complications were recorded in 15 (23.4%) patients. In the multivariate logistic regression model, 3 independent risk factors for complication were screened out, including age (OR=1.16, 95% CI 1.01-1.34, p=.042), anterior reconstruction (OR=3.40, 95% CI 1.03-11.2, p=.045), and preoperative CB (OR=1.06, 95% CI 1.00-1.12, p=.036). The mean SRS-22 total and domain scores for the entire cohort showed improvement at last follow-up. However, in the noncomplication group, the improvements in SRS-22 scores were more substantial. Postoperative neurological and mechanical complications are common medical events following LSHV resection. The age, anterior column reconstruction, and preoperative coronal balance were the independent risk factors. Compared to the noncomplication group, the improvements in HRQOL are blunted in the complication group.

Imaging characteristics and surgical effect for symmetrical lumbar hemivertebrae

Objective: To analyze the imaging characteristics and surgical effect for symmetrical lumbar hemivertebrae in pediatric patients. Methods: The data of 13 patients with hemivertebrae locating in the lumbar spine symmetrically were retrospectively analyzed, and all the patients were treated in Beijing Children's Hospital from January 2015 to September 2021. The mean age of the patients was 6.2 (2.9, 9.3) years. There were 8 males and 5 females. The data of coronal/sagittal plane including segmental Cobb angle, cranial/caudal compensatory curve, thoracic kyphosis, thoracolumbar kyphosis, sacral obliquity, and lumbar lordosis were recorded through long cassette spinal radiographs. Associated anomalies and the relationship between hemivertebrae and posterior component were recorded through computerized tomography (CT) and magnetic resonance imaging (MRI). All the patients received surgery, and their pre-and postoperative imaging data were compared. Results: A total of 26 hemivertebraes were found, in which 80.8% (21/26) located below L2. Hemivertebraes in 10 patients were separated by a mean 1-2 normal vertebrae. Most hemivertebraes along with the corresponding posterior component were unison (21/26, 80.8%). The Cobb angles of cranial compensatory curve (13.9°±7.2°) was more serious than that of caudal compensatory curve (5.5°±5.0°)(P=0.04). The lumbar lordosis and thoracic kyphosis was 20.2°±15.0° and 18.7°±9.2°, respectively. Six patients complicated with sacral obliquity, while 7 patients complicated with thoracolumbar lordosis. Associated anomalies were found in 6 (46.2%) patients through CT and MRI. Eleven patients received one-or two-stage posterior hemivertebrae resection with short segmental fusion, and 2 patients received one-stage hemivertebrae resection with long segmental fusion. All the surgery were completed successfully without serious complications such as nerve injury, infection, and implant failure. The mean follow-up period was (42.4±10.2) months. At the last follow-up point, the correction rate of segmental Cobb angle and cranial compensatory curve was 83.3%±15.6% and 38.1%±10.4%, respectively, showing significant improvement (P<0.05). Although the caudal compensatory curve, sacral obliquity, and thoracic kyphosis improved after surgery, the data showed no significant difference compared to that before surgery. Thoracolumbar lordosis in all patients were corrected. Conclusions: Most hemivertebraes in such spinal deformity locate in lower lumbar region with a high incidence of anomalies. Individualized treatment based on patients' condition is essential for the complicated spinal deformity.

Presence of compensatory curve predicts postoperative curve progression in congenital scoliosis after thoracolumbar hemivertebra resection and short fusion.

To investigate the impact of preoperative compensatory curve on the postoperative curve progression in congenital scoliosis (CS) patients following thoracolumbar hemivertebra (HV) resection and short fusion. This study retrospectively reviewed a consecutive cohort of patients with CS who underwent thoracolumbar HV resection and short fusion with a minimum of 2 years follow-up. According to the preoperative curve pattern, patients were divided into compensatory curve group non-compensatory curve group. Based on the postoperative coronal curve evolution, patients were further divided into the progressed group (Group P, with curve decompensation ≥ 20°) and the non-progressed group (Group NP, characterized by well-compensated curves). A total of 127 patients were included in this study, with 31 patients in the compensatory curve group and 96 patients in the non-compensatory curve group. The incidence of postoperative coronal curve progression was significantly higher in the compensatory curve group than that in non-compensatory curve group (35.5% vs. 13.5%, p = 0.007). In the compensatory curve group, patients who experienced postoperative curve progression showed fewer fusion segments (p = 0.001), greater preoperative UIV translation (p = 0.006), greater preoperative LIV tilt (p = 0.017), and larger postoperative UIV tilt (p < 0.001) compared with patients in group NP. Multiple logistic regression demonstrated that the shorter fusion segments and greater postoperative UIV tilt were two independent risk factors for postoperative curve progression. The presence of the compensatory curve was associated with a higher incidence of postoperative curve progression in patients with CS who underwent thoracolumbar HV resection and short fusion. Shorter fusion segments and greater postoperative UIV tilt were found to be the risk factors for postoperative curve progression.

UMPL- VINS: Generalized SLAM for multi-scene metaverse applications

The use of line features to improve the localization accuracy of point-based visual inertial SLAM (VINS) is of increasing interest because of the additional constraints they can provide on the scene structure. It is found that although the introduction of line features improves the accuracy of relative position estimation in some scenes due to the additional constraints, the two constraints only achieve an equalization for the estimated relative position. Therefore, in some environments two constraints can reduce the accuracy of the single-feature constraint algorithm and also make the real-time performance of the system more challenging. To address such issues, in this paper, we design a generalized SLAM system with point-line features that can be applied to multiple metaverse scenarios. We first enhance the image frames used for feature extraction by eliminating motion blur frames through the fuzzy metric method and mutation modeling of velocity and rotation. Then we improve the traditional line detection model by short line fusion, uniform distribution of line features, and refinement of edge features to obtain high-quality line features for building SLAM. Finally, based on the application of point features and line features for different scenes, a point and line feature separation-union model is proposed. In addition, we design a transformation model for line-point features to enhance the processing of point-line features. Experimental results on EuRoc, TUM_VI, KITTI, PennCOSYVIO and our own recorded dataset prove that the method proposed in this paper realizes a generalized SLAM with point and line features applied to multi-scenes with good advantages.

Minimally Invasive Controlled Growing Rods for the Surgical Treatment of Early-Onset Scoliosis—A Surgical Technique Video

Background: Spinal deformities in children and adolescents can be easily divided into those occurring and diagnosed before the age of 10—early-onset scoliosis—and those occurring and diagnosed after the age of 10—late-onset scoliosis. When the curvature continues to progress and exceeds a Cobb angle of more than 60–65 degrees, surgical treatment should be considered. The most common treatment procedure for EOS is the surgical correction of the deformity using standard growing rods (SGRs), and in the case of congenital defects with additional hemivertebrae, it is the resection of the hemivertebra and short fusion. Minimally invasive controlled growing rods (MICGRs) need to be distracted every 6–9 months through a minimally invasive approach that involves sedation and neuromonitoring to obtain the best possible correction while minimizing complications. The aim of our study is to present a less-invasive surgical technique for MICGR implantation based on a two-case presentation—early-onset idiopathic scoliosis and congenital kyphosis. The surgical technique is the less-invasive percutaneous and subfascial implantation of MICGRs without long incisions in the back. Conclusions: The use of MICGRs is an alternative and safe surgical technique for patients undergoing surgical treatment for EOS. Without the risk of metallosis, like in other implant systems, and the need for replacement after 2 years of use, like in using magnetically controlled growing rods (MCGRs), the MICGR system can be used as a less-invasive procedure, allowing for the avoidance of many periodic invasive procedures in children with a wider opening of the spine (like in using standard growing rods), minimizing the number of planned hospitalizations, reducing the length of hospital stays, and reducing the physical and mental burdens on young patients, parents, and families.

How does cervical sagittal profile change after the spontaneous compensation of global sagittal imbalance following one- or two-level lumbar fusion.

This study aimed to evaluate the cervical sagittal profile after the spontaneous compensation of global sagittal imbalance and analyze the associations between the changes in cervical sagittal alignment and spinopelvic parameters. In this retrospective radiographic study, we analyzed 90 patients with degenerative lumbar stenosis (DLS) and sagittal imbalance who underwent short lumbar fusion (imbalance group). We used 60 patients with DLS and sagittal balance as the control group (balance group). Patients in the imbalance group were also divided into two groups according to the preoperative PI: low PI group (≤ 50°), high PI group (PI > 50°). We measured the spinal sagittal alignment parameters on the long-cassette standing lateral radiographs of the whole spine. We compared the changes of spinal sagittal parameters between pre-operation and post-operation. We observed the relationships between the changes in cervical profile and spinopelvic parameters. Sagittal vertical axis (SVA) occurred spontaneous compensation (p = 0.000) and significant changes were observed in cervical lordosis (CL) (p = 0.000) and cervical sagittal vertical axis (cSVA) (p = 0.023) after surgery in the imbalance group. However, there were no significant differences in the radiographic parameters from pre-operation to post-operation in the balance group. The variations in CL were correlated with the variations in SVA (R = 0.307, p = 0.041). The variations in cSVA were correlated with the variations in SVA (R=-0.470, p = 0.001). Cervical sagittal profile would have compensatory changes after short lumbar fusion. The spontaneous decrease in CL would occur in patients with DLS after the spontaneous compensation of global sagittal imbalance following one- or two-level lumbar fusion. The changes of cervical sagittal profile were related to the extent of the spontaneous compensation of SVA.

Spinopelvic morphology impacts on postoperative proximal junctional kyphosis in congenital scoliosis with thoracolumbar hemivertebrae.

It aims to investigate the lumbar and pelvic morphology in congenital scoliosis with thoracolumbar hemivertebrae and its impact on proximal junctional kyphosis (PJK) incidence after hemivertebra resection and short fusion. 23 congenital scoliosis patients with thoracolumbar hemivertebra aged between 10 and 18years were enrolled in the retrospective study. Spinopelvic sagittal parameters were analyzed on whole-spine standing lateral radiographs preoperatively, one-week postoperatively and at the final follow-up. Pearson correlations were calculated for local kyphosis (LK), lumbar and pelvic morphology parameters. Binary logistic regression and receiver operating characteristics (ROC) curve analysis were performed to identify the risk factors for PJK. Thoracolumbar hemivertebra caused LK of 29.2° ± 17.3°, an increased lumbar lordosis (LL) (-64.7° ± 16.3°), lower LL apex (52.2% at L5), and small pelvic incidence (PI) (36.8° ± 6.6°). LK was correlated with lumbar morphology parameters, including LL (r = -0.837), upper arc of LL (LLUA) (r = -0.879), thoracolumbar kyphosis (TLK) (r = 0.933), thoracic kyphosis (TK) (r = 0.762) and TK apex (TKA) (r = -0.749). Surgical treatment improved the lumbar morphology, but not pelvic morphology. At the final follow-up, LL had returned to its preoperative value (p = 0.158). PJK occurred in 30.4% of cases as a compensatory mechanism. Preoperatively, significant differences of parameters between non-PJK and PJK groups were observed in LK and TLK. Binary logistic regression identified three independent risk factors for PJK: preoperative LLA (OR = 0.005, 95%CI = 0.000-0.287, p = 0.011), preoperative TLK (OR = 1.134, 95%CI = 1.001-1.286, p = 0.048), and preoperative lumbar lordosis morphology type (OR = 5.507, 95%CI = 1.202-25.227, p = 0.028). However, residual LK after surgery was not correlated with PJK incidence. ROC curve analysis verified that preoperative TLK > 22.59° was associated with increased PJK incidence after surgery. Lumbar morphology changes as a compensatory mechanism beneath the thoracolumbar hemivertebra. However, a stable pelvis tends to allow the LL to return to its preoperative value. PJK occurred as a cranial compensatory mechanism for increasing LL and corrected TLK. A larger TLK (> 22.59°) was an independent risk factor for PJK incidence in patients with type 2 and 3A lumbar lordosis morphology.

Comparison of the efficacy of the convex side short fusion combined with concave side single growing rod technique and the traditional bilateral growing rod technique in the treatment of early onset scoliosis

ObjectivesThe application of a growing rod technique can retain the growth and development potential of the spine and thorax while controlling the progression of scoliosis deformity. Theoretically, convex side short fusion combined with a concave side single growing rod technique can significantly reduce the asymmetric growth of the spine in the vertex region in most patients. However, the final clinical outcome of various techniques is yet to be clearly determined and compared between studies. Therefore, we compared the efficacy of these two growing rod techniques in treating early onset scoliosis.MethodsIn a retrospective study of 152 EOS patients seen between 2013.1 and 2019.12, 36 cases of EOS patients were selected for inclusion. Among the 36 cases, 11 cases were treated with convex side short fusion combined with a concave side single growing rod technique, group (A) The remaining 25 cases were treated with traditional bilateral growing rod technique, group (B) Age, gender, etiology, follow-up time, Cobb angle of main curve, T1-S1 height, coronal trunk shift, sagittal vertical axis (SVA), Cobb angle of thoracic kyphosis at last follow-up, and Cobb angle at proximal junction kyphosis of the first and last post-operation follow-up were recorded. In addition, internal fixation related complications, infection, nervous system complications were recorded as well.ResultsThere was no statistically significant difference between group A and group B in preoperative age, Cobb angle of main curve, coronal trunk shift, T1-S1 height, SVA, Cobb angle of thoracic kyphosis (p > 0.05). However, at the last follow-up (Group A, mean 4.4 ± 1.01 years; Group B, mean 3.6 ± 0.01 years) the Cobb angle of the main curve was less and T1-S1 height greater in group A compared with group B (p < 0.05). There was no statistically significant difference between group A and group B in the correction rate of the Cobb angle of the main curve or the growth rate of T1-S1 height (p > 0.05). There was no statistically significant difference in the coronal imbalance ratio, thoracic kyphosis abnormality ratio, or the occurrence PJK ratio between group A and group B at the last follow-up (p > 0.05), but the sagittal imbalance ratio and internal fixation abnormality ratio were higher in group A than in the group B (p < 0.05).ConclusionsDuring the treatment of EOS, both the convex side short fusion combined with concave side single growing rod technique and traditional bilateral growing rod technique can correct the Cobb angle of main curve with no significant hindering of the spinal growth observed. The traditional bilateral growing rod technique has advantages in control of the sagittal balance of the spine, and the complications associated with internal fixation were lower.

Benchmark Values for Construct Survival and Complications by Type of ASD Surgery.

The aim of this study was to provide benchmarks for the rates of complications by type of surgery performed. Prospective multicenter database. We have previously examined overall construct survival and complication rates for ASD surgery. However, the relationship between type of surgery and construct survival warrants more detailed assessment. Eight surgical scenarios were defined based on the levels treated, previous fusion status [primary (P) vs. revision (R)], and three-column osteotomy use (3CO): short lumbar fusion, LT-pelvis with 5 to 12 levels treated (P, R, or 3CO), UT-pelvis with 13 levels treated (P, R, or 3CO), and thoracic to lumbar fusion without pelvic fixation, representing 92.4% of the case in the cohort. Complication rates for each type were calculated and Kaplan-Meier curves with multivariate Cox regression analysis was used to evaluate the effect of the case characteristics on construct survival rate, while controlling for patient profile. A total of 1073 of 1494 patients eligible for 2-year follow-up (71.8%) were captured. Survival curves for major complications (with or without reoperation), while controlling for demographics differed significantly among surgical types ( P <0.001). Fusion procedures short of the pelvis had the best survival rate, while UT-pelvis with 3CO had the worst survival rate. Longer fusions and more invasive operations were associated with lower 2-year complication-free survival, however, there were no significant associations between type of surgery and renal, cardiac, infection, wound, gastrointestinal, pulmonary, implant malposition, or neurological complications (all P >0.5). This study suggests that there is an inherent increased risk of complication for some types of ASD surgery independent of patient profile. The results of this paper can be used to produce a surgery-adjusted benchmark for ASD surgery with regard to complications and survival. Such a tool can have very impactful applications for surgical decision-making and more informed patient counseling. Level III.