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Background and Objectives: This study is a retrospective analysis aimed at understanding the incidence and risk factors of proximal junctional kyphosis (PJK) following long-instrumented spinal fusion from L1 to the sacrum in patients with mild to moderate sagittal imbalance. Materials and Methods: It recruited consecutive patients undergoing instrumented fusion from L1 to the sacrum for degenerative lumbar disease between June 2006 and November 2019 in a single institution. The patients' preoperative clinical data, muscle status at T12-L1 on magnetic resonance images, and sagittal spinopelvic parameters were analyzed. Univariate analysis was used to compare clinical and radiographic data between PJK and non-PJK patients. Logistic regression analysis was used to investigate the independent risk factors for PJK. Results: A total of 56 patients were included in this study. The mean age at surgery was 67.3 years and mean follow-up period was 37.3 months. In total, 10 were male and 46 were female. PJK developed in 23 (41.1%) out of 56; of these patients, 20 (87.0%) developed PJK within 1 year postoperatively. In the univariate analysis between PJK and non-PJK patients, the PJK group showed more frequent osteoporosis, lower body mass index, smaller cross-sectional area (CSA) and more fat infiltration (FI) in erector spinae muscle at T12-L1 and larger preoperative TLK and PT with statistical significance ( p < 0.05). In the logistic regression analysis, severe (>50%) FI in erector spinae muscle (OR = 43.60, CI 4.10-463.06, R 2 N = 0.730, p = 0.002) and osteoporosis (OR = 20.49, CI 1.58-264.99, R 2 N = 0.730, p = 0.021) were statistically significant. Conclusions: Preexisting severe (>50%) fat infiltration in the erector spinae muscle and osteoporosis were independent risk factors associated with PJK following instrumented fusion from L1 to the sacrum, but age was not a risk factor.

Background : Teriparatide is an anabolic agent for osteoporosis and is believed to improve the bone healing process. Previous studies showed that teriparatide could enhance not only fracture healing but also spine fusion. It has been reported that use of teriparatide could promote the spine fusion process and decrease mechanical complications. However, there was no consensus regarding optimal treatment duration. The purpose of this study was to compare surgical outcomes between short-duration and long-duration teriparatide treatment after lumbar fusion surgery in elderly patients. Materials and Methods : All consecutive patients older than 60 years who underwent 1-level lumbar fusion surgery for degenerative diseases between January 2015 and December 2019 were retrospectively reviewed. Based on the duration of teriparatide treatment (daily subcutaneous injection of 20 µg teriparatide), patients were subdivided into two groups: a short-duration (SD) group (<6 months) and a long-duration (LD) group (≥6 months). Mechanical complications, such as screw loosening, cage subsidence, and adjacent vertebral fractures, were investigated. Postoperative 1-year union rate was also evaluated on computed tomography. Clinical outcomes were recorded using visual analog scale (VAS) and Oswestry Disability Index (ODI). Between-group differences for these radiographic and clinical outcomes were analyzed. Results : Ninety-one patients were reviewed in this study, including sixty patients in the SD group and thirty-one patients in the LD group. Their mean age was 72.3 ± 6.2 years, and 79 patients were female. Mean T-score was -3.3 ± 0.8. Cage subsidence (6.7% vs. 3.2%), screw loosening (28.3% vs. 35.5%), and adjacent vertebral fracture (6.7% vs. 9.7%) were not significantly different between the SD and LD groups. Union rate at 1-year postoperative was 65.0% in the SD group and 87.1% in the LD group ( p = 0.028). Both groups showed improvement in VAS and ODI after surgery. However, the differences of VAS from preoperative to 6 months and 1 year postoperative were significantly higher in the LD group. Conclusions : Longer teriparatide treatment after lumbar fusion surgery resulted in a higher union rate at 1-year postoperative than the shorter treatment. Also, it could be more beneficial for clinical outcomes.

Background: To investigate the incidence and risk factors of coronal vertical vertebral body fracture (CV-VBF) during lateral lumbar interbody fusion (LLIF) for degenerative lumbar disease., Methods: Clinical data, including age, sex, body mass index, and bone mineral density, were reviewed. Radiological assessments, such as facet joint arthrosis, intervertebral disc motion, index disc height, and cage profiles, were conducted. Posterior instrumentation was performed using either a single or staged procedure after LLIF. Demographic and surgical data were compared between patients with and without VBF., Results: Out of 273 patients (552 levels), 7 (2.6%) experienced CV-VBF. Among the 552 levels, VBF occured in 7 levels (1.3%). All VBF cases developed intraoperatively during LLIF, with no instances caused by cage subsidence during the follow-up period. Sagittal motion in segments adjacent to VBF was smaller than in others (4.6° ± 2.6° versus 6.5° ± 3.9°, P = 0.031). The average grade of facet arthrosis was 2.5 ± 0.7, indicating severe facet arthrosis. All fractures developed due to oblique placement of a trial or cage into the index disc space, leading to a nutcracker effect. These factors were not related to bone quality., Conclusions: CV-VBF after LLIF occurred in 2.6% of patients, accounting for 1.3% of all LLIF levels. A potential risk factor for VBF involves the nutcracker-impinging effect due to the oblique placement of a cage. Thorough preoperative evaluations and surgical procedures are needed to avoid VBF when considering LLIF in patients with less mobile spine., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Objective: To analyze the characteristics of "severe" dynamic sagittal imbalance (DSI) in patients with adult spinal deformity (ASD) and establish criteria for them., Methods: We retrospectively analyzed 102 patients with ASD presenting four cardinal signs of lumbar degenerative kyphosis. All patients underwent deformity corrective surgery and were divided into three groups according to the diagnostic criteria based on the Oswestry disability index and dynamic features (△Time walk : time until C7 sagittal vertical axis [C7SVA] reaches ≥ 20 cm after the start of walking) of sagittal imbalance. The paravertebral back muscles were analyzed and compared using T2-weighted axial imaging. We performed a statistically time-dependent spinopelvic sagittal parameter analysis of full standing lateral lumbar radiographs. Lumbar flexibility was analyzed using dynamic lateral lumbar radiography., Results: The patients were classified into the mild (△Time walk  ≥ 180 s, 35 patients), moderate (180 s > △Time walk  ≥ 30 s, 38 patients), and severe (△Time walk  < 30 s, 29 patients) groups. The back muscles in the severe group exhibited a significantly higher signal intensity (533.4 ± 237.5, p < 0.05) and larger area of fat infiltration (35.2 ± 5.4, p < 0.05) than those in the mild (223.8 ± 67.6/22.9 ± 11.9) and moderate groups (294.4 ± 214.7/21.6 ± 10.6). The analysis of lumbar flexibility revealed significantly lower values in the severe group (5.8° ± 2.5°, p < 0.05) than in the mild and moderate groups (14.2° ± 12.4° and 11.4° ± 8.7°, respectively). The severe group had significantly lower lumbar lordosis (LL, 25.1° ± 22.7°, p < 0.05) and Pelvic incidence-LL mismatch (PI-LL, 81.5° ± 26.6°, p < 0.001) than those of the mild (8.2° ± 16.3°/58.7° ± 18.8°) and moderate (14.3° ± 28.6°/66.8° ± 13.4°) groups. On receiver operating characteristic curve analysis, PI-LL was statistically significant, with an area under the curve of 0.810 (95% confidence interval) when the baseline was set at 75.3°. The severe group had more postoperative complications than the other groups., Conclusions: Our results suggest the following criteria for severe DSI: C7SVA > 20 cm within 30 s of walking or standing, a rigid lumbar curve < 10° on dynamic lateral radiographs, and a PI-LL mismatch > 75.3°., (© 2024. The Author(s).)

Study Design: Retrospective comparative study., Objectives: To investigate the clinical and radiological outcomes after anterior column realignment (ACR) through pre-posterior release-anterior-posterior surgery (PAP) and minimally invasive surgery -lateral lumbar interbody fusion (MIS-LLIF) using hybrid anterior-posterior surgery (AP)., Methods: A total of 91 patients who underwent ACR with long fusions from T10 vertebra to the sacropelvis with a follow-up period of at least 2 years after corrective surgery for adult spinal deformity were included and divided into two groups by surgical method: AP and PAP. AP was performed in 26 and PAP in 65 patients. Clinical outcomes and radiological parameters were investigated and compared. A further comparison was conducted after propensity score matching between the groups., Results: The more increase of LL and decrease of PI-LL mismatch were observed in the PAP group than in the AP group postoperatively. After propensity score matching, total operation time and intraoperative bleeding were greater, and intensive care unit care and rod fracture were more frequent in the PAP group than in the AP group with statistical significance. Reoperation rate was higher in PAP (29.2%) than in AP (16.7%) without statistical significance., Conclusions: PAP provides a more powerful correction for severe sagittal malalignment than AP procedures. AP results in less intraoperative bleeding, operation time, and postoperative complications. Therefore, this study does not suggest that one treatment is superior to the other., Level of Evidence: III., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: The authors declare no competing interests regarding any of the materials or devices described in this article. No benefits in any form have been received or will be received from a commercial party directly or indirectly related to the subject of this study. JA, nothing to disclose; SIK, nothing to disclose; YCK, nothing to disclose; KTK, nothing to disclose; YHK, nothing to disclose; SMK, nothing to disclose; TK, nothing to disclose; KYH, nothing to disclose.

Purpose: Adjacent segment disease (ASD) is a common complication in fusion surgery. In the event of solid segmental fusion, previous implants can be removed or preserved during fusion extension for ASD. To compare the surgical outcomes of patients with and without implants and analyzes the risk factors for postoperative mechanical complications., Methods: Patients who underwent fusion extension for lumbar ASD from 2011 to 2019 with a minimum 2 year follow-up were retrospectively reviewed. Spinopelvic parameters were measured preoperatively and postoperatively. Clinical outcomes and surgical complications were compared between groups with implants preserved and removed. Risk factors for mechanical complications, including clinical, surgical, and radiographic factors were analyzed., Results: Sixty-nine patients (mean age, 69.9 ± 6.9 years) were included. The mean numbers of initial and extended fused segments were 2.8 ± 0.7 and 2.7 ± 0.7, respectively. Previous implants were removed in 43 patients (R group) and preserved in 26 patients (P group). Both groups showed an improvement in clinical outcomes without between-group differences. The operation time was significantly longer in R group (260 vs 207 min, p < 0.001). Mechanical complications occurred in 13 patients (12 in R group and 1 in P group) and reoperation was needed in 3 patients (R group). Implant removal, index fusion surgery including L5-S1, and postoperative sagittal malalignment were risk factors for mechanical complications., Conclusion: Implant removal was a risk factor for mechanical complications. Index fusion surgery including L5-S1 and postoperative sagittal malalignment were also risk factors for mechanical complications., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: The purpose of this study was to investigate autophagy in an extruded disc and to compare this activity with the activity in the remaining disc after lumbar disc herniation in the same patient., Methods: In total, 12 patients (females 4, males 8) with the extruded type of lumbar disc herniation (LDH) were surgically treated. Their mean age was 54.3 ± 15.8 years (range: 29 ~ 78 years). The mean interval from the occurrence of symptoms to the operation was 9.8 ± 9.4 weeks (range: 2 ~ 24 weeks). The extruded discs were excised, and the remaining disc material removed, to prevent recurrence of herniation. Immediately after specimen collection, all tissues were stored at -70 °C prior to analysis. Autophagy was assessed immunohistochemically and via Western blotting for Atg5, Atg7, Atg12, Atg12L1, and Beclin-1. And the relationship between autophagy and apoptosis was investigated by correlation analysis of caspase-3 with autophagy proteins., Results: The expression levels of autophagic markers were significantly increased in the extruded discs compared to the remaining discs within the same patients. The mean expression levels of Atg5, Atg7, Atg12, and Beclin-1 in extruded discs were statistically significantly higher than those in the remaining discs (P < 0.01, P < 0.001, P < 0.01, and P < 0.001 respectively)., Conclusions: The autophagic pathway was more active in extruded disc material than in remaining disc material within the same patient. This may explain spontaneous resorption of the extruded disc after LDH., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: Junctional failures after long fusion stopping at L5 can present at both proximal and distal ends. The purpose of this study was to investigate incidences and risk factors of proximal junctional failure (PJF) and distal junctional failure (DJF) after long lumbar instrumented fusion stopping at L5 for adult spinal deformity., Methods: Sixty-three patients who underwent long fusion surgery stopping at L5 with a minimum follow-up of 3 years were reviewed retrospectively. PJF and DJF were defined as newly developed back pain and/or radiculopathy with corresponding radiographic failures. The incidence and risk factors of each junctional failure were analyzed using a log-rank test and Cox proportional hazards model., Results: Twelve men and 51 women were included in our study. Their mean age was 68.5 ± 7.0 years and the mean follow-up period was 84.5 ± 45.3 months. PJF and DJF occurred in 17 (27%) and 16 patients (25.4%), respectively. PJF and DJF developed at median durations of 32.1 months and 13.3 months, respectively, showing no significant difference between the two. Three patients presented with both PJF and DJF. Risk factors for PJF included lower body mass index, higher preoperative lumbar lordosis, and higher postoperative sagittal vertical axis (SVA) (hazard ratio, 0.570, 1.055, and 1.040, respectively). For DJF, higher preoperative SVA was an independent risk factor (hazard ratio, 1.010)., Conclusions: After long fusion surgery stopping at L5, PJF and DJF occurred at similar rates. Lower body mass index, higher preoperative lumbar lordosis, and higher postoperative SVA were risk factors for PJF. Higher preoperative SVA was an independent risk factor for DJF., (Copyright © 2023 Elsevier Inc. All rights reserved.)

(1) Background: Recently, Escherichia coli -derived recombinant human bone morphogenetic protein-2 ( E. coli -derived rhBMP-2) has been increasingly applied to different types of spinal surgeries and reported to achieve successful fusion. This pilot study aimed to evaluate the clinical efficacy and safety of rhBMP-2 in patients undergoing posterior instrumented fusions for unstable spinal fractures. (2) Methods: This study included ten consecutive patients undergoing spinal surgery using E. coli -derived rhBMP-2 with more than one year of follow-up. Radiologic outcomes were compared, including the average fracture healing period, local kyphosis correction, and clinical outcomes between preoperative and the last follow-up. (3) Results: The average time of radiographic union was 99.9 ± 45.4 (62-192) days, with an average use of 5.2 ± 3.9 months of anabolic agents. Radiologic parameters such as anterior vertebral height and vertebral wedge angle were significantly corrected postoperatively and at the last follow-up. Clinical outcomes other than leg pain were significantly improved after the surgery. In addition, four patients with preoperative neurologic deficits showed improved neurologic status. (4) Conclusions: Combined with the anabolic agents, applying E. coli -derived rhBMP-2 to the fractured vertebral body could be an effective surgical treatment for unstable spinal fractures. Further trials are needed to validate this result.

(1) Background: Although metastatic spine disease is increasing, the debate on therapeutic modality remains due to the heterogeneity of tumors and patients. This study aims to evaluate the efficacies of surgery and risk factors for patients' survival from potentially unstable spinal metastasis of non-small cell lung cancer; (2) Methods: Twenty-two patients undergoing surgery and radiotherapy (group I) were compared with 22 patients undergoing radiotherapy alone (group II) using propensity score matching in a 1-to-1 format. Clinical outcomes included the performance status and ambulatory status. In addition, independent risk factors for patients' survival were evaluated, including the molecular targeted therapy for mutations; (3) Results: deterioration in neurologic status was only observed in group II compared to group I (22.7% vs. 0%, p -value = 0.018). In addition, five patients in the surgery group showed improved Frankel grades. Regarding the patients' survival, a smoking history of more than ten pack-years (hazard ratio (HR) = 12.18), worse performance status (HR = 6.86), and absence of mutations (HR = 3.39) were the independent risk factors; (4) Conclusions: Spinal surgery with radiotherapy could have advantages for improving the neurologic status including ambulation for potentially unstable spine due to metastasis. Thus, surgery should be considered for patients with a longer life expectancy resulting from better performance status and use of the targeted therapy.

Purpose: To investigate the interaction of telomerase activity and telomere length on neuro-protection or neuro-degeneration effects after spinal cord injury (SCI)., Methods: A contusive SCI model was developed using 56 Sprague-Dawley rats. Seven rats were allocated into acute injury phase groups (1, 3, 8, 24, and 48 h), and sub-acute and chronic injury phase groups (1, 2, and 4 weeks). Telomerase activity was assessed by telomerase reverse transcriptase (TERT) and telomeric repeat binding factor-2 (TERF-2). Differentiation of activated neural stem cells was investigated by co-expression of neuronal/glial cell markers. Apoptosis expression was also investigated by caspase-3, 8, and 9 using terminal deoxynucleotidyl transferase dUTP nick end labelling staining. Immunofluorescence staining and western blotting were performed for quantitative analyses., Results: Expression of TERT increased gradually until 24 h post-injury, and was decreased following SCI (P < 0.05). TERF-2 also was increased following SCI until 24 h post-injury and then decreased with time (P < 0.05). Co-localization of TERT and TERF-2 was higher at 24 h post-injury. High expression of TERT was seen in neurons (Neu N Ab), however, expression of TERT was relatively lower in astrocytes and oligodendrocytes. Apoptosis analysis showed persistent high expression of caspases-3, -9, and -8 during the observation period., Conclusions: Increased TERT and TERF-2 activity were noted 24 h post-injury in the acute phase of SCI with TERF-2 maintaining telomeric-repeat length. Our results suggest that increased activity of telomere maintenance may be related to neuro-protective mechanisms against subsequent apoptosis resulting from DNA damage after acute SCI., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: The aim of this study was to investigate time-dependent rates and indications of unplanned reoperation and to evaluate the most common indication depending on the time interval after pedicle subtraction osteotomy (PSO) for correction of thoracolumbar kyphosis in patients with ankylosing spondylitis (AS)., Methods: A total of 321 consecutive patients with AS (284 men; mean age 43.8 years) with thoracolumbar kyphosis who underwent PSO were included. Patients who underwent reoperation after the index surgery were divided according to the duration of the follow-up period., Results: A total of 51 patients (15.9%) underwent unplanned reoperations. The reoperation groups had greater preoperative and postoperative C7 sagittal vertical axis (SVA), and less lordotic postoperative osteotomy angle (-4.3° ± 18.6° vs -15.0° ± 13.7°, p < 0.001). The perioperative change in SVA was not significantly different between groups (-10.0 ± 7.1 cm vs -10.0 ± 5.1 cm, p = 0.970), while that in the osteotomy angle was significantly different (-22.4° ± 21.3° vs -30.0° ± 11.5°, p = 0.014). Most reoperations (45.1%; 23/51) were performed within 2 weeks of the initial operation. Within 2 weeks, the most common cause of reoperation was neurological deficit in 10 patients, with a cumulative reoperation rate of 3.2%. After 3 years, the most common complications were mechanical complications in 8 patients, accounting for 15.7% (8/51) of patients. Overall, the most common indications for reoperation were mechanical complications (17 patients; 5.3%), followed by neurological deficits (12 patients; 3.7%)., Conclusions: PSO may be the most effective surgical procedure for the correction of thoracolumbar kyphosis in patients with AS. However, 51 patients (15.9%) required an unplanned reoperation.

Study Design: Retrospective case-control study., Objectives: The aim of this study was to develop a simple and reliable imaging parameter to predict postoperative ambulatory status in patients with metastatic epidural spinal cord compression (MESCC)., Methods: Sixty-three patients with MESCC underwent spine surgery because of neurologic deficits were included. On preoperative axial MRI, the cord compression ratio was analyzed for postoperative ambulatory status. The relationship between other imaging features, such as fracture of the affected vertebra and increased T2 signal intensity of the spinal cord at the compression level, and the postoperative ambulatory status were also analyzed., Results: Cord compression ratio and increased T2 signal change of the spinal cord were significantly different between the postoperative ambulatory group and the non-ambulatory group. Receiver operating characteristic analysis showed that the optimal cut-off value was 0.84. In the multivariate regression analysis, only a cord compression ratio of more than 0.84 was significantly associated with postoperative ambulatory status (odds ratio = 10.80; 95% confidence interval = 2.79-41.86; P = .001). Interobserver/intraobserver agreements were strong for the cord compression ratio, however those agreements were weak for increased T2 signal intensity., Conclusions: On preoperative MRI, the cord compression ratio may predict postoperative ambulatory status in patients with MESCC. The measurement of this imaging parameter was simple and reliable. This imaging predictor may be helpful for both clinicians and patients.

Objective: We investigated the long-term effects of bone cement-augmented instrumentation in multilevel lumbar fusions in a retrospective cohort study. The use of cement-augmented screws is one of the techniques used to reduce early mechanical failure in treating multilevel lumbar fusion, especially in the elderly. However, little information is available regarding the long-term effects., Methods: A total of 51 patients who had undergone ≥3 levels of lumbar fusion were divided into two groups according to the use of bone cement-augmented screw fixation involving the upper instrumented vertebra: 22 patients in the cement-augmented group (group I) and 29 patients in the non-cement-augmented group (group II). Analysis of radiographic adjacent disc segment degeneration (ASD) revealed patients with lumbosacral fusion with a similar degree of osteoporosis. Radiologic ASD was defined as progression of >2 UCLA (University of California, Los Angeles) grades at 2 years postoperatively. Other sagittal parameters and the preoperative magnetic resonance imaging Pfirrmann grades at the adjacent levels, possibly related to ASD, were also analyzed., Results: No significant differences were present in the preoperative demographic and radiographic parameters between the 2 groups. However, the postoperative kyphotic changes at 3 months were greater for the non-cement-augmented group. In terms of the long-term effects, the incidence of radiologic ASD (group I, n = 20 [95.2%]; vs group II, n = 15 [53.6%]) was significantly higher in the cement-augmented group. Logistic regression analysis of radiologic ASD, including other clinical and radiologic parameters, postoperative pelvic incidence-lumbar lordosis mismatch (odds ratio, 5.201; 95% confidence interval, 1.123-24.090; P = 0.035), and cement augmentation (odds ratio, 20.193; 95% confidence interval, 2.195-185.729; P = 0.008) showed a significant correlation with the development of radiologic ASD at 2 years postoperatively., Conclusions: Although bone cement-augmented screw implantation can prevent kyphotic deformation at the proximal junction of upper instrumented vertebra in the early postoperative stages of multilevel lumbar fusion, a careful selection of patients is required because of possibly accelerated degeneration of adjacent segments., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Lumbar interbody fusion (LIF) is an excellent treatment option for a number of lumbar diseases. LIF can be performed through posterior, transforaminal, anterior, and lateral or oblique approaches. Each technique has its own pearls and pitfalls. Through LIF, segmental stabilization, neural decompression, and deformity correction can be achieved. Minimally invasive surgery has recently gained popularity and each LIF procedure can be performed using minimally invasive techniques to reduce surgery-related complications and improve early postoperative recovery. Despite advances in surgical technology, surgery-related complications after LIF, such as pseudoarthrosis, have not yet been overcome. Although autogenous iliac crest bone graft is the gold standard for spinal fusion, other bone substitutes are available to enhance fusion rate and reduce complications associated with bone harvest. This article reviews the surgical procedures and characteristics of each LIF and the osteobiologics utilized in LIF based on the available evidence.

Background: We hypothesized that posterior osteotomy prior to ACR (Anterior column realignment) through P-A-P surgical sequence would permit a greater correction for deformity corrective surgery than the traditional A-P sequence without posterior osteotomy. This study aimed to determine the impact of the P-A-P sequence on the restoration of lumbar lordosis (LL) compared to the A-P sequence in deformity corrective surgery for adult spinal deformity (ASD) patients and to identify the characteristics of patients who require this sequence.  METHODS: Between 2017 and 2019, 260 ASD patients who had undergone combined corrective surgery were reviewed retrospectively. This study included 178 patients who underwent posterior osteotomy before the ACR (P-A group) and 82 patients who underwent the A-P sequence (A-P group). Sagittal spinopelvic parameters were determined from pre- and postoperative whole-spine radiographs and compared between the groups. To find better indications for the P-A-P sequence, we conducted additional analysis on postoperative outcomes of patients in the A-P group.  RESULTS: The P-A group showed a significantly higher change in LL (53.7° vs. 44.3°, p < 0.001), C7 sagittal vertical axis (C7 SVA: 197.4 mm vs. 146.1 mm, p = 0.021), segmental lordosis (SL) L2/3 (16.2° vs. 14.4°, p = 0.043), SL L3/4 (16.2° vs. 13.8°, p = 0.004), and SL L4/5 (15.1° vs. 11.3°, p = 0.001) compared to the A-P group. At the final follow-up, pelvic incidence (PI) minus LL mismatch (PI - LL mismatch) was significantly higher in the A-P group (13.4° vs. 2.9°, p < 0.001). Stepwise logistic regression analysis showed that age ≥ 75 years (odds ratio [OR] = 2.151; 95% confidence interval [CI], 1.414-3.272; p < 0.001), severe osteoporosis (OR = 2.824; 95% CI, 1.481-5.381; p = 0.002), rigid lumbar curve with dynamic changes in LL < 10° (OR = 5.150; 95% CI, 2.296-11.548; p < 0.001), and severe facet joint osteoarthritis (OR = 4.513; 95% CI, 1.958-10.402; p < 0.001) were independent risk factors for PI - LL mismatch ≥ 10° after A-P surgery., Conclusion: P-A-P sequence for deformity corrective surgery in ASD offers greater LL correction than the A-P sequence. Indications for the procedure include patients aged ≥ 75 years, severe osteoporosis, rigid lumbar curve with dynamic change in LL < 10°, or more than four facet joints of Pathria grade 3 in the lumbar region., (© 2022. The Author(s).)

Background: Despite being a promising strategy, current chemotherapy for gastric cancer (GC) is limited due to adverse side effects and poor survival rates. Therefore, new drug-delivery platforms with good biocompatibility are needed. Recent studies have shown that nanoparticle-based drug delivery can be safe, eco-friendly, and nontoxic making them attractive candidates. Here, we develop a novel selenium-nanoparticle based drug-delivery agent for cancer treatment from plant extracts and selenium salts., Results: Selenium cations were reduced to selenium nanoparticles using Kaempferia parviflora (black ginger) root extract and named KP-SeNP. Transmission electron microscopy, selected area electron diffraction, X-ray diffraction, energy dispersive X-ray, dynamic light scattering, and Fourier-transform infrared spectrum were utilized to confirm the physicochemical features of the nanoparticles. The KP-SeNPs showed significant cytotoxicity in human gastric adenocarcinoma cell (AGS cells) but not in normal cells. We determined that the intracellular signaling pathway mechanisms associated with the anticancer effects of KP-SeNPs involve the upregulation of intrinsic apoptotic signaling markers, such as B-cell lymphoma 2, Bcl-associated X protein, and caspase 3 in AGS cells. KP-SeNPs also caused autophagy of AGS by increasing the autophagic flux-marker protein, LC3B-II, whilst inhibiting autophagic cargo protein, p62. Additionally, phosphorylation of PI3K/Akt/mTOR pathway markers and downstream targets was decreased in KP-SeNP-treated AGS cells. AGS-cell xenograft model results further validated our in vitro findings, showing that KP-SeNPs are biologically safe and exert anticancer effects via autophagy and apoptosis., Conclusions: These results show that KP-SeNPs treatment of AGS cells induces apoptosis and autophagic cell death through the PI3K/Akt/mTOR pathway, suppressing GC progression. Thus, our research strongly suggests that KP-SeNPs could act as a novel potential therapeutic agent for GC., (© 2022. The Author(s).)

Hydroxyapatite (HA) derived from salmon bone byproducts is used as a green support for the nanostructured nickel catalysts applied in the methanation of carbon dioxide (CO 2 ). Undoped nickel catalysts and various ceria-doped nickel supported on hydroxyapatite (HA) were prepared by coimpregnation. Characteristics of the as-prepared catalysts were investigated by the various techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), hydrogen temperature-programmed reduction (H 2 -TPR), carbon dioxide temperature-programmed desorption (CO 2 -TPD), and energy-dispersive X-ray spectroscopy (EDX). The catalyst activity was assessed throughout CO 2 methanation in the low-temperature range of 225-350 °C with the molar ratio of H 2 /CO 2 = 4/1. The function of HA and ceria provided a high dispersity of nickel particles over the catalyst surface with the size range of 24.5-25.8 nm, leading to improvement in the reduction and CO 2 adsorption capacity of the catalysts as well as enhancing the catalytic efficiency in CO 2 methanation. The 10Ni/HA catalyst reduced at suitable conditions of 400 °C for 2 h showed the highest catalytic performance among the tested catalysts. CO 2 conversion and CH 4 selectivity reached 76.6 and 100% at a reaction temperature of 350 °C, respectively. The results show that the Ni/HA sample doped with 6.0 wt % ceria was the best, with the CO 2 conversion and the CH 4 selectivity reaching 92.5% and 100%, respectively, at a reaction temperature of 325 °C., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

Objective: The objective of this study was to investigate the incidence and risk factors of rod fractures (RFs) after a single-level lumbar pedicle subtraction osteotomy (PSO) using a side-tightening (ST) pedicle screw system., Methods: Fifty-seven consecutive patients who underwent a single-level lumbar PSO for the degenerative sagittal imbalance at a single institution were retrospectively reviewed. All surgeries were performed by a single surgeon using an ST pedicle screw system. Demographic, surgical, and radiographic data were analyzed to investigate the incidence and risk factors for RF., Results: Seven (12.3%) patients showed RF after PSO. Four patients had bilateral RFs, and 3 patients had unilateral RFs. The location of the RF was at the PSO level in 6 of 7 patients. The ratio of adjacent interbody fusion was significantly different between the group with RF and the group without RF (16.7% vs. 74.0%, P = 0.004). The preoperative segmental angle at the PSO vertebra (-6.1° ± 5.5° vs. -1.7° ± 4.6°, P = 0.049) and postsurgical change in lumbar lordosis (48.4° ± 8.8° vs. 37.8° ± 11.9°, P = 0.033) were significantly different between the 2 groups. Risk factor analysis using stepwise logistic regression analysis revealed that the absence of an adjacent interbody cage (odds ratio = 0.011, 95% confidence interval = 0.000-0.390, P = 0.013) was a significant risk factor., Conclusions: The incidence of RF after a single-level lumbar PSO using the ST pedicle screw system was 12.3% in our cohort. The absence of an adjacent interbody cage was a significant risk factor for RF., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Study Design: This is a retrospective comparative cohort study., Purpose: To investigate the prevalence of anterior resorption of the cervical spine in ankylosing spondylitis (AS) and its relationship with sagittal alignment., Overview of Literature: This study believes that no published reports exist regarding the relationship between anterior resorption and spinopelvic alignment., Methods: This retrospective study included 238 patients with AS who underwent surgical correction for thoracolumbar kyphosis. Of these, 80 patients with complete subaxial ankylosis were selected and divided into two groups: groups 1 (consisting of 28 patients with anterior bony resorption) and 2 (consisting of 52 patients without anterior resorption). Cervical sagittal parameters were analyzed and compared between the two groups., Results: The average lateral diameter measured in patients with C5 anterior resorption was 84.2%±7.8% (62.4%-96.8%). Cervical lordosis was 8.7°±13.4° and 10.9°±11.5° in groups 1 and 2 (p=0.556), respectively. No significant differences were noted between the two groups on spinopelvic alignment in the T1 slope (52.2°±11.1° and 53.3°±9.9° in groups 1 and 2, respectively; p=0.742), C2-C7 sagittal vertical axis (SVA; 6.2±1.7 cm and 6.2±1.8 cm in groups 1 and 2, respectively; p=0.978), C7 SVA (14.3±4.9 cm and 14.6±6.2 cm in groups 1 and 2, respectively; p=0.823), or T1 pelvic angle (27.1°±8.9° and 31.6°±11.2° in groups 1 and 2, respectively; p=0.382). Correlation analyses were significant between the extent of anterior resorption and sagittal parameters, C2-C7 lordosis (R2=-0.428, p=0.021), and T1-T4 kyphosis (R2=-0.375, p=0.045)., Conclusions: Anterior bony resorption could develop by stress concentration. However, the development was not related to the sagittal alignment. The particular segments involved in developing anterior resorption varied, possibly because of their dependence on the preceding pattern of ankylosis.

Background: Previous studies of patient positioning during spinal surgery evaluated intraoperative or immediate postoperative outcomes after short-instrumented lumbar fusion. However, patient positioning during long-instrumented fusion for an adult spinal deformity (ASD) might be associated with differences in intraoperative parameters such as blood loss and longer-term outcomes such as spine alignment, and comparing types of surgical tables in the context of these larger procedures and evaluating longer-term outcome scores seem important., Questions/purposes: (1) Do blood loss and the number of transfusions differ between patients who underwent multi-level spinal fusion with a Wilson frame and those with a four-poster frame? (2) Does restoration of lumbar lordosis and the sagittal vertical axis differ between patients who underwent surgery with the use of one frame or the other? (3) Do clinical outcomes as determined by Numeric Rating Scale and Oswestry Disability Index scores differ between the two groups of patients? (4) Are there differences in postoperative complications between the two groups?, Methods: Among 651 patients undergoing thoracolumbar instrumented fusion between 2015 and 2018, 129 patients treated with more than four levels of initial fusion for an ASD were identified. A total of 48% (62 of 129) were eligible; 44% (57 of 129) were excluded because of a history of fusion, three-column osteotomy, or surgical indications other than degenerative deformity, and another 8% (10 of 129) were lost before the minimum 2-year follow-up period. Before January 2017, one surgeon in this study used only a Wilson frame; starting in January 2017, the same surgeon consistently used a four-poster frame. Forty patients had spinal fusion using the Wilson frame; 85% (34 of 40) of these had follow-up at least 2 years postoperatively (mean 44 ± 13 months). Thirty-two patients underwent surgery using the four-poster frame; 88% (28 of 32) of these were available for follow-up at least 2 years later (mean 34 ± 6 months). The groups did not differ in terms of age, gender, BMI, type of deformity, or number of fused levels. Surgical parameters such as blood loss and the total amount of blood transfused were compared between the two groups. Estimated blood loss was measured by the amount of suction drainage and the amount of blood that soaked gauze. The decision to transfuse blood was based on intraoperative hemoglobin values, a protocol that was applied equally to both groups. Radiologic outcomes including sagittal parameters and clinical outcomes such as the Numerical Rating Scale score for back pain (range 0-10; minimal clinically important difference [MCID] 2.9) and leg pain (range 0-10; MCID 2.9) as well as the Oswestry Disability Index score (range 0-100; MCID 15.4) were also assessed through a longitudinally maintained database by two spine surgeons who participated in this study. Repeated-measures analysis of variance was used to compare selected radiologic outcomes between the two groups over time., Results: Blood loss and the total amount of transfused blood were greater in the Wilson frame group than in the four-poster frame group (2019 ± 1213 mL versus 1171 ± 875 mL; mean difference 848 [95% CI 297 to 1399]; p = 0.003 for blood loss; 1706 ± 1003 mL versus 911 ± 651 mL; mean difference 795 [95% CI 353 to 1237]; p = 0.001 for transfusion). Lumbar lordosis and the sagittal vertical axis were less restored in the Wilson frame group than in the four-poster frame group (7° ± 10° versus 18° ± 14°; mean difference -11° [95% -17° to -5°]; p < 0.001 for lumbar lordosis; -22 ± 31 mm versus -43 ± 27 mm; mean difference 21 [95% CI 5 to 36]; p = 0.009 for the sagittal vertical axis). Such differences persisted at 2 years of follow-up. The proportion of patients with the desired correction was also greater in the four-poster frame group than in the Wilson frame group immediately postoperatively and at 2 years of follow-up (50% versus 21%, respectively; odds ratio 3.9 [95% CI 1.3 to 11.7]; p = 0.02; 43% versus 12%, respectively; odds ratio 5.6 [95% CI 1.6 to 20.3]; p = 0.005). We found no clinically important differences in postoperative patient-reported outcomes including Numeric Rating Scale and Oswestry Disability Index scores, and there were no differences in postoperative complications at 2 years of follow-up., Conclusion: The ideal patient position during surgery for an ASD should decrease intra-abdominal pressure and induce lordosis as the abdomen hangs freely and hip flexion is decreased. The four-poster frame appears advantageous for long-segment fusions for spinal deformities. Future studies are needed to extend our analyses to different types of spinal deformities and validate radiologic and clinical outcomes with follow-up for more than 2 years., Level of Evidence Level: III, therapeutic study., Competing Interests: This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2021R1I1A1A01059501). Each author certifies that there are no funding or commercial associations (consultancies, stock ownership, equity interest, patent/licensing arrangements, etc.) that might pose a conflict of interest in connection with the submitted article related to the author or any immediate family members. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research® editors and board members are on file with the publication and can be viewed on request., (Copyright © 2021 by the Association of Bone and Joint Surgeons.)

Objective: Although radiotherapy (RT) is recommended for multiple myeloma (MM) involving spine, the treatment of choice between reconstructive surgery with RT and RT alone for pathologic vertebral fractures (PVFs) associated with structural instability or neurologic compromises remains controversial. The purpose of this study was to evaluate the clinical efficacies of reconstructive surgery with adjuvant RT for treatment of MM with PVFs by comparing with matched cohorts treated with RT alone., Methods: Twenty-eight patients underwent reconstructive surgery followed by RT between 2008 and 2015 in a single institution, for management of PVFs associated with structural instability of the spine and/or neurologic compromises (group I). Twentyeight patients were treated with RT alone (group II) after propensity score matching in a 1-to-1 format based on instability of the spine, as well as age and performance. Clinical outcomes including the overall survival rates, duration of independent ambulation, neurological status, and numeric rating scale (NRS) for back pain were compared., Results: Clinical and radiological features before treatment were similar in both groups. The median survival period was similar between the two groups. However, the mean duration of independent ambulation was significantly longer in group I (88.8 months; 95% confidence interval [CI], 66.0-111.5) than in group II (39.4 months; 95% CI, 25.2-53.6) (log rank test; p=0.022). Deterioration of Frankel grade (21.4% vs. 60.7%, p=0.024) and NRS for back pain (2.7±2.2 vs. 5.0±2.7, p=0.000) at the last follow-up were higher in the group II. Treatment-related complications were similar in both groups., Conclusion: In patients with unstable PVFs due to MM, reconstructive surgery may yield superior clinical outcomes compared with RT alone in maintaining independent ambulation and neurological status, as well as pain control despite similar median survival and complications.

Study Design: This study is a retrospective analysis of a case., Purpose: The purpose of this study is to investigate the fracture patterns and risk factors of sacral insufficiency fractures (SIFs) to improve their diagnosis in clinical practice., Overview of Literature: SIFs occur when normal stresses are applied to a bone with decreased density, most often due to osteoporosis. Individuals who receive lumbosacral fusion procedures may also suffer from increased incidents of SIFs because of decreased bone density related to aging., Methods: In total, 55 patients with SIFs were retrospectively investigated in this study. The study population was divided into lumbosacral fusion (n=20) and non-fusion (n=35) groups. Subsequently, the patients' demographic characteristics, comorbidities, medication history, results of diagnostic imaging studies, and bone mineral density were assessed. The fracture patterns were classified either according to the five typical types (H-pattern bilateral vertical plus horizontal component, unilateral vertical only, bilateral vertical only, unilateral vertical plus horizontal component, and horizontal only fracture) or atypical types., Results: In total, 44 of 55 patients (80%) suffered from more than one senile disease and received corresponding medications that caused secondary osteoporosis. A total of 12 patients had S1 lumbosacral fixation. Moreover, three of these 12 patients who developed a SIF immediately after a lumbosacral fracture had an unstable sacral U fracture. The remaining nine patients showed fracture patterns similar to the non-fusion patients. Single-photon emission computed tomography (SPECT)/computed tomography (CT) can identify fracture recurrence in previously healed fractures. In total, 24 patients (43.6%) had fractures of the pelvis, femur, and thoracolumbar spine., Conclusions: SIF develops in elderly patients with multiple adult diseases that can induce secondary osteoporosis. Such fractures may occur in the patients with instrumented lumbosacral fusion. Importantly, some patients showed stress fractures after multilevel instrumented lumbosacral fusion, whereas others showed insufficiency fractures. The different fracture patterns correspond to different grades of SIF, and SPECT/CT can easily identify the fracture status.

Background: Studies explaining the relationship between hip and spine reported that spinal corrective surgery affected acetabular orientation and changes in pelvic tilt were capable of influencing radiographic measures of acetabular coverage. This study aimed to assess the change in coronal parameters for acetabular coverage as a result of adult spinal deformity (ASD) correction and to analyze the relationship between the postoperative changes in sagittal spinopelvic parameters and coronal acetabular coverage parameters., Methods: Fifty-two consecutive patients who had undergone multilevel spinal surgical correction were enrolled and evaluated. Coronal acetabular coverage parameters included Tönnis angle (TA), lateral center edge angle (LCEA), and the angle of Sharp (SA). All radiographic parameters were evaluated at the preoperative and the postoperative 1 year. Paired t test was used to determine whether there were significant changes between the time points. Bivariate correlation and linear regression analysis were used to assess the relationship between the postoperative changes of spinal alignment and acetabular orientation., Results: The surgical correction resulted in significant decrease of TA, increase of LCEA and SA, respectively (p < 0.001). The changes in pelvic tilt (PT) demonstrated weak correlation on TA (β = 0.117, p < 0.001 for right; β = 0.111, p < 0.001 for left)., Conclusions: Although the surgical correction of ASD significantly changed PT resulting in increased acetabular lateral coverage parameters, the correlation between the changes of PT following sagittal correction of ASD and acetabular coverage parameters was low., Trial Registration: This study was retrospectively registered with approval by the institutional review board (IRB) of our institution (approval number: KHNMC-2020-10-010)., (© 2021. The Author(s).)

During lateral lumbar interbody fusion (LLIF), unintended intraoperative endplate injury (IEPI) can occur and thereafter lead cage subsidence. The aim of this study was to investigate the incidence of IEPI during LLIF, and its predisposing factors. A retrospective review was conducted on consecutive patients (n = 186; mean age, 70.0 ± 7.6 years) who underwent LLIF at 372 levels. Patient's demographic and surgical data were compared between patients with and without IEPI. Also, the radiographic data of each level were compared between intact and IEPI segments. IEPI was identified at 76 levels (20.4%) in 65 patients. The incidences of IEPI at every 100 consecutive segments were not different. When 372 segments were analyzed independently, sagittal disc angle (DA) in the extended position (4.3° ± 3.6° at IEPI segments vs. 6.4° ± 4.0° at intact segments), the difference between sagittal DA in the extended position and cage angle (- 2.2° ± 4.0° vs. 0.0° ± 3.9°), and the difference between preoperative disc height and cage height (- 5.4 mm ± 2.4 mm vs. - 4.7 mm ± 2.0 mm) were different significantly. Also, endplate sclerosis was more common at intact segments than IEPI segments (33.2% vs. 17.3%). Multivariate analysis showed that male sex (odds ratio [OR] 0.160; 95% confidence interval [CI] 0.036-0.704), endplate sclerosis (OR 3.307; 95% CI 1.450-8.480), and sagittal DA in the extended position (OR 0.674; 95% CI 0.541-0.840) were significant associated factors for IEPI. IEPI was correlated not with surgeon's experience, but with patient factors, such as sex, preoperative disc angle, and endplate sclerosis. Careful surgical procedures should be employed for patients with these predisposing factors., (© 2021. The Author(s).)

Animal placentae can be used as health-promoting food ingredients with various therapeutic efficacies, but their use is limited by their unpleasant odor and taste. This study aimed to investigate the possibility of deodorization of sheep placenta via yeast fermentation. A yeast strain was successfully isolated and identified as a novel Brettanomyces strain ( Brettanomyces deamine kh3). The deodorizing efficacy of fermentation of the sheep placenta with B. deamine kh3 was evaluated by 42 panels, based on evaluation of preference, ranking, and aroma profiles, and compared with normal placenta and placenta fermented with B. bruxellensis . The results of the sensory evaluation indicated that fermentation of the sheep placenta with B. deamine kh3 may improve its palatability by increasing flavors such as that of grass (tree), rubber, and burnt, and by decreasing the odor and soy sauce flavor. Solid-phase microextraction-gas chromatography (SPME-GC) showed that major off-flavors in sheep placenta, such as ammonia, dimethyl disulfide, and 1,3-dioxolane, were completely diminished in the sheep placenta fermented with B. deamine kh3. This study presents those major volatile compounds, including 2-isobutyl\-4,4-dimethyl-1,3-dioxane, and 3-methyl-1-butanol, could be crucial in improving the palatability of the sheep placentae fermented with B. deamine kh3. This study provides a good starting point for the industrial application of a new deodorization method.

Objective: Recently, new patient-reported outcome measures (PROMs) of the spine were designed to overcome the limitations of previous spinal PROMs and to consider the whole spine as a single kinetic functional unit. Owing to the significance of spine-hip-knee and global body balance, the spine and lower extremities cannot be considered separately. However, no reports have evaluated lower-extremity functional outcome using PROMs after lumbar spine surgery. The authors aimed to elucidate changes in hip and knee PROMs after lumbar interbody fusion and to evaluate the sagittal spinopelvic radiographic parameters that were most strongly correlated with lower-extremity PROMs., Methods: In 2018, the authors consecutively evaluated patients who underwent lumbar interbody fusion surgery with at most three levels. Preoperative and 1-year postoperative clinical and radiographic data were assessed. Spinal functional outcomes were measured with the Oswestry Disability Index (ODI), visual analog scale (VAS) for pain, and Scoliosis Research Society-22r (SRS-22r) questionnaire. Lower-extremity functional outcomes were evaluated with the Harris Hip Score (HHS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Linear regression was used to evaluate the relationship between spinal and lower-extremity PROMs and spinopelvic radiographic parameters., Results: The authors enrolled 67 patients, with a mean age of 66.4 years. The average number of surgical levels was 1.7. All assessed PROMs improved significantly after surgery (p < 0.001 for ODI, p < 0.001 for VAS, p = 0.017 for SRS-22r, p = 0.042 for HHS, and p = 0.033 for WOMAC). Spinopelvic parameters, including lumbar lordosis (LL), pelvic tilt (PT), C7 sagittal vertical axis, and sagittal radiographic parameters of hip and knee, significantly improved after surgery. On linear regression analysis, HHS and WOMAC correlated with LL and PT, respectively (β = 0.554 and p = 0.043 for correlation of HHS with LL; β = 1.573 and p = 0.021 for correlation of WOMAC with PT)., Conclusions: The current study demonstrated that lumbar fusion surgery may induce postoperative improvements in lower-extremity functional and radiological outcomes. However, among radiographic parameters, changes in LL and PT were the most strongly associated with lower-extremity PROMs.

Background: More caudal osteotomy is believed to lead to greater sagittal correction; however, the osteotomy level and whether or not to use iliac screw fixation (ISF) are topics of on-going debate. The aim of this study was to compare clinical and radiographic outcomes after revisional lumbar pedicle subtraction osteotomy (PSO) for fixed sagittal imbalance (FSI) according to the osteotomy level and ISF., Methods: All consecutive patients who underwent revisional PSO (at L3 or L4) for FSI in a single institute from July 2006 to January 2014 were investigated retrospectively. Thirty-eight patients with at least 2-year follow-up were finally included. Clinical outcomes including the visual analogue scale (VAS) and Oswestry Disability Index (ODI) were investigated. Radiographic spinopelvic parameters were analyzed according to the level of PSO, the degree of correction, and the use of ISF., Results: The mean number of fused segments after PSO was 6.6 ± 1.8. Sagittal vertical axis (SVA) was restored after the surgery (12, 2.5, and 5.2 cm at preoperative, postoperative, and the last follow-up, respectively). PSO was performed at L3 in 16 patients and at L4 in 22 patients. The osteotomy level was not associated with any changes of spinopelvic parameters (pelvic tilt [PT] or lumbar lordosis) or sagittal alignment (T1-pelvic angle [TPA] or SVA). However, better TPA restoration was achieved with more osteotomy resection angle (P = 0.031). ISF group showed significant improvement in postoperative pelvic orientation (PT and ratio of PT to pelvic incidence) which was maintained until the last follow-up., Conclusions: Although postoperative sagittal alignment was different in FSI patients according to the osteotomy level, pelvic orientation improved in ISF group. Also, the degree of correction showed significant associations with sagittal alignment. When performing revisional PSO for FSI, spine surgeon should carefully consider how to correct rather than where to do the osteotomy, and the role of ISF., Competing Interests: Declaration of Competing Interest All authors declare no conflict of interest., (Copyright © 2020 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.)

Background: To date, there is a paucity of reports clarifying the change of spinopelvic parameters in patients with adult spinal deformity (ASD) who underwent long segment spinal fusion using iliac screw (IS) and S2-alar-iliac screw (S2AI) fixation., Methods: A retrospective review of consecutive patients who underwent deformity correction surgery for ASD between 2013 and 2017 was performed. Patients were divided into two groups based on whether IS or S2AI fixation was performed. All radiographic parameters were measured preoperatively, immediately postoperatively, and the last follow-up. Demographics, intraoperative and clinical data were analyzed between the two groups. Additionally, the cohort was subdivided according to the postoperative change in pelvic incidence (PI): subgroup (C) was defined as change in PI ≥5° and subgroup (NC) with change < 5°. In subgroup analyses, the 2 different types of postoperative change of PI were directly compared., Results: A total of 142 patients met inclusion criteria: 111 who received IS and 31 received S2AI fixation. The IS group (65.6 ± 26°, 39.8 ± 13.8°) showed a significantly higher change in lumbar lordosis (LL) and upper lumbar lordosis (ULL) than the S2AI group (54.4 ± 17.9°, 30.3 ± 9.9°) (p < 0.05). In subgroup (C), PI significantly increased from 53° preoperatively to 59° postoperatively at least 50% of IS cohort, with a mean change of 5.8° (p < 0.05). The clinical outcomes at the last follow-up were significantly better in IS group than in S2AI group in terms of VAS scores for back and leg. The occurrence of sacroiliac joint pain and pelvic screw fracture were significantly greater in S2AI group than in IS group (25.8% vs 9%, p < 0.05) and (16.1% vs 3.6%, p < 0.05)., Conclusions: Compared with the S2AI technique, the IS technique usable larger cantilever force demonstrated more correction of lumbar lordosis, and possible increase in pelvic incidence. Further study is warranted to clarify the clinical impaction of these results., (© 2021. The Author(s).)

Objective: The most catastrophic symptom of proximal junctional failure (PJF) following long instrumented fusion surgery for adult spinal deformity (ASD) is neurological deficits. Although previous reports have shown that PJF usually developed during the early postoperative period, some patients showed late neurological deficits. The aim of this study was to report the incidence, characteristics, and surgical outcomes of PJF with late neurological deficits., Methods: Patients surgically treated for ASD at a single institution were retrospectively reviewed. Among them, the patients requiring revision surgery for newly developed neurological deficits at least 6 months after the initial surgery were included. Patient demographic, radiographic, surgical, and clinical data were investigated. Neurological status was assessed using the Frankel grading system., Results: PJF with late neurological deficits developed in 18 of 385 patients (4.7%). The mean age at the onset of neurological deficits was 72.0 ± 6.0 years, and the median time from the initial surgery was 4.5 years. The most common pathology of PJF was adjacent disc degeneration and subsequent canal stenosis (11 patients). Five patients showed disc degeneration with aseptic bone destruction. Fractures at the upper instrumented vertebra (UIV), UIV + 1, and UIV + 2 occurred in 2, 3, and 2 patients, respectively. Ossification of the yellow ligament, which had not been found at the first surgery, was identified in 6 patients. Eight patients showed improvement of their neurological deficits and 10 patients showed no improvement by the final follow-up. Perioperative major complications occurred in 8 of 18 patients., Conclusions: The incidence of PJF with late neurological deficits following ASD surgery was 4.7% in this cohort. The patients showed several morphological features. After revision surgery, perioperative complications were common and the prognosis for improved neurological status was not favorable.

Objective: We investigated the characteristics and revision rate of junctional failure after surgical correction for thoracolumbar kyphosis in patients with ankylosing spondylitis., Methods: A total of 230 patients had undergone surgical correction for thoracolumbar kyphosis from 2010 to 2019. The state of ankylosis between the uppermost instrumented vertebra (UIV) and UIV+1 and between the lowermost instrumented vertebra (LIV) and LIV-1 was analyzed using a modified Stoke ankylosing spondylitis spine score. Proximal junctional failure (PJF) and distal junctional failure (DJF) were defined as any type of symptomatic junctional failure., Results: Of the 230 patients, 23 (10.0%) had developed junctional failure. Of these 23 patients, 16 had had partial ankylosis and 7 had had complete ankylosis. PJF had developed in 10 patients and DJF in 13. The most common type of junctional failure was a junctional fracture, which developed in 12 patients. PJF had developed by UIV fracture in 4 patients, UIV+1 fracture in 1 patient, and UIV+2 in 1 patient. DJF had developed by LIV fracture in 6 patients, metallic failure in 5, and progression of DJF in 2 patients. The average time to the development of PJF and DJF was 13 months and 12.4 months, respectively. All 10 patients with PJF and 7 of 13 patients with DJF (53.8%) had required reoperation. Of the 12 patients with junctional fracture, 11 (91.7%) had undergone reoperation., Conclusions: Of the 23 patients with junctional failure, 16 had had immature ossification of the anterior longitudinal ligament. Therefore, to prevent junctional failure, the state of ankylosis seems to be important for selecting the fusion level after osteotomy. Once junctional failure has developed, however, reoperation should be considered owing to the stress concentration at the UIV or LIV., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Study Design: A retrospective study., Objective: The aim of this study was to investigate proximal junctional kyphosis (PJK) after lumbosacral long fusion according to preoperative Roussouly and lumbar degenerative kyphosis (LDK) types., Summary of Background Data: Although previous studies have suggested some risk factors for PJK, the effects of preoperative grade of sagittal imbalance and paraspinal muscles degeneration on PJK remain unclear., Methods: Eighty-seven patients who had undergone lumbosacral fusion more than five levels with available clinical and radiological data were enrolled. The presence of PJK defined as sagittal Cobb angle ≥20° between the uppermost instrumented vertebra (UIV) and two supra-adjacent vertebrae at postoperative 2-year radiographs was recorded. Its occurrence was compared according to preoperative Roussouly and LDK types (Takemistu type) and the degree of paraspinal muscle degeneration at the upper level of UIV. Other sagittal radiographic parameters were also measured., Results: In this series, 28 patients (group I, 32.2%) showed radiological PJK, whereas 59 patients did not show radiological PJK (non-PJK patients, group II, 67.8%) at postoperative 2 years. PJK presented more prevalence in type III and type IV of LDK types (26/27, 96.3%). However, Roussouly types did not show any significant difference in PJK prevalence. In radiological parameters, a larger preoperative SVA (P = 0.018) and PI-LL (P = 0.015) were associated with PJK. Also, smaller quantity and lower quality of paraspinal muscles at T12-L1 level showed significant (P < 0.001) relationship with PJK. On multivariate logistic regression, higher LDK type (odds ratio [OR]: 2.11, 95% confidence interval [CI]: 1.24-3.56), smaller quantity (OR: 1.03, 95% CI: 1.00-1.07), and higher degree of paraspinal muscle degeneration (OR: 1.46, 95% CI: 0.92-2.31) were independent predictors of postoperative PJK., Conclusion: Although various factors are related to PJK following long segment fusion, preoperative conditions such as LDK types and degree of paraspinal muscle degeneration might be related to the development of PJK.Level of Evidence: 3., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

The purpose of this study was to report the characteristics of SIFs after ILSF and discuss its management focusing on pelvic deformation. We retrospectively reviewed all consecutive patients who underwent ILSF for degenerative disc diseases during the period between 2000 and 2017 and were diagnosed as SIF at our institute. The clinical and radiographic data were reviewed on their medical charts. Treatment outcomes for SIF were also investigated. Eight patients (all females) were included in this study. Mean age at SIF diagnosis was 72 years, and the mean follow-up period was 3.8 years (range 1-7 years). SIF developed average 7.5 years (range 1 month-17 years) after the index ILSF. Fracture patterns were unilateral vertical in four, bilateral vertical in three, and horizontal in 1 patient. Unlike patients with unilateral vertical SIF, patients with bilateral vertical or horizontal SIF showed a marked increase of pelvic incidence (PI) by mean 17.0°±5.0° and sagittal vertical axis (SVA) by mean 4.5 ± 2.2 cm, compared to the respective values before the onset of abrupt pain. All patients with unilateral vertical SIF were treated favorably by conservative management, however sacropelvic fixation was inevitable in patients with bilateral vertical or horizontal SIF. Bilateral vertical or horizontal SIF showed marked changes on sagittal radiographic parameters including PI and SVA. Although unilateral vertical SIF has benign courses that responded well to conservative management, bilateral vertical or horizontal SIF is likely to need surgical treatment. Treatment plan should be determined depending on fracture pattern and pelvic deformation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Study Design: A propensity score-matched cohort study., Objective: The objective of this study was to compare the radiologic and clinical outcomes of camptocormia in Parkinson disease (PD) with degenerative sagittal imbalance (DSI) patients., Summary of Background Data: Camptocormia in PD and DSI could be characterized by a dynamic deformity. However, no study has directly evaluated the outcomes of patients with camptocormia and DSI., Methods: Thirteen consecutive PD patients undergoing surgical correction for camptocormia were matched in a 1-to-2 format with 26 patients in the DSI group by propensity score-matching. Radiologic outcomes, including paravertebral muscle changes, and clinical outcomes were compared between the 2 groups. The rate of proximal junctional problems and reoperations were assessed., Results: PD patients with camptocormia had significantly greater preoperative coronal and sagittal malalignments (29.9 vs. 16.9 mm, P=0.019; 142.8 vs. 64.4 mm, P=0.0001, respectively) and weakness of paravertebral muscles compared with the DSI patients. Regarding the clinical outcomes, reoperations were significantly higher in the camptocormia group, compared with the DSI group (53.8% vs. 7.7%, P=0.001). Moreover, proximal junctional failure was developed in 8 patients in the camptocormia group, while 1 patient in the DSI group (61.5% vs. 3.8%, P=0.0001). In subgroup analysis, independent risk factors for the proximal junctional failure were the total fusion levels (hazard ratio=0.26, P=0.018) and the degree of fatty changes of the paravertebral muscles (hazard ratio=1.15, P=0.048)., Conclusions: PD patients undergoing spinal surgery for camptocormia had global malalignment and higher rates of complications compared with DSI patients. Patients should be appropriately counseled regarding the increased risk of operative complications and closely followed for incipient failure.

Study Design: Retrospective case-control study., Objective: To investigate the effects of postoperative sagittal alignment on radiographic adjacent segment degeneration (ASD) after lumbar fusion surgery., Summary of Background Data: ASD is one of inherent problems with fusion surgery. Many confounding factors are related to the development of ASD. Recently, sagittal alignment has been emphasized for its significance on ASD., Methods: Seventy-three patients who underwent four-level lumbar fusion surgery (L2-S1) were divided into two groups according to postoperative sagittal alignment (pelvic incidence-lumbar lordosis [PI-LL] ≥ or <9°): 44 patients (matched group, including 10 patients who underwent pedicle subtraction osteotomy [PSO] at L4) and 29 patients (mismatched group). The general demographics, radiographic parameters, and clinical outcomes were recorded. Preoperative disc degeneration at L1-2 was evaluated by Pfirrmann grade and Kellgren-Lawrence (K-L) grade. Disc degeneration at L1-2 was evaluated by the K-L grade on 2-year postoperative X-rays., Results: The incidence of radiographic ASD (11 [25%] vs. 16 patients [55%], P = 0.02) and Oswestry Disability Index (ODI) scores (36.9 ± 19.9 vs. 49.4 ± 20.7, P = 0.015) at postoperative 2 years were significantly higher in the mismatched group. There were no significant differences in other demographic and radiographic parameters between the two groups. On subgroup analysis between 10 PSO patients and the mismatched group, the mismatched group showed a higher incidence of radiographic ASD (16 [55%] vs. 1 patient [10%], P = 0.041) and worse ODI scores (49.7 ± 20.5 vs. 39.0 ± 20.7, P = 0.040). Preoperative Pfirrmann grade at L1-2 (odds ratio [OR] = 4.191, 95% confidence interval [CI]: 1.754-10.013, P = 0.001) and postoperative PI-LL mismatch (OR = 4.890, 95% CI: 1.550-15.427, P = 0.007) showed significant relationships with the development of radiographic ASD at postoperative 2 years., Conclusion: The restoration of optimal sagittal alignment, even with PSO, may provide a protective effect on the development of radiographic ASD, although the preoperative disc degeneration grade was a risk factor for radiographic ASD., Level of Evidence: 3.

Background: Decompressive laminectomy alone for degenerative lumbar scoliosis (DLS) is not recommended because it can lead to further instability. However, it is uncertain whether instability at the decompressed segments is directly affected by laminectomy or the natural progression of DLS. The purpose of this study was to evaluate the surgical outcome of decompressive laminectomy alone for DLS with spinal stenosis and to determine whether the procedure leads to post-laminectomy instability (PLI)., Methods: We retrospectively reviewed 60 patients with DLS. They were divided into 2 groups according to PLI criteria: stable group and PLI group. The PLI group was subdivided into 2 groups based on the level of PLI: the first group that showed PLI at the index laminectomy level (PLI-I) and the second group that showed PLI at another level other than the laminectomy level (PLI-NI). Radiological evaluation was performed to determine factors associated with the progression of DLS. Pain and disability outcomes were assessed., Results: There were 34 patients (56.7%) in the stable group and 26 patients (43.3%) in the PLI group. Twelve patients (20.0%) underwent revision surgery. Eleven patients (18.3%) showed PLI at the index segments (PLI-I group), and 15 patients (25%) showed PLI at the adjacent or cephalad segments, not related to the laminectomy site (PLI-NI group). Four patients underwent revision surgery in the stable group and 8 in the PLI group. Survivorship analyses revealed that the predicted survivorship of DLS was 90.0% at 12 months and 86.4% at 24 months after laminectomy., Conclusions: The development of PLI was not always related to laminectomy at the index level. However, PLI developed more rapidly at the index level, compared to the natural progression of the scoliotic curve at the adjacent segments., Competing Interests: CONFLICT OF INTEREST: No potential conflict of interest relevant to this article was reported., (Copyright © 2020 by The Korean Orthopaedic Association.)

Background: There is a paucity of reports clarifying the implication of knee osteoarthritis (OA) on spinal sagittal alignment of patients undergone surgery for lumbar spine. This study aimed to analyze how osteoarthritic knee affects radiographic and clinical results of degenerative lumbar disease patients undergone lumbar fusion., Methods: We retrospectively reviewed the medical records and radiographs of 74 consecutive degenerative lumbar disease patients who underwent posterior instrumentation and fusion surgery between May 2016 and June 2017 and were followed up for minimum 3 years postoperatively. The patients were divided into 2 groups according to the severity of knee OA by Kellgren-Lawrence grading (KLG) scale (group I, KLG 1 or 2 [n = 39]; group II, KLG 3 or 4 [n = 35]). Patient demographic data, comorbidities, spinal sagittal parameters and clinical scores were extracted and compared at preoperative, postoperative 1 month and the ultimate follow-up between the groups. In radiographic assessment, sagittal alignment parameters and sagittal balance were used. In clinical assessment, the scores of Oswestry disability index (ODI) and Scoliosis Research Society questionnaire (SRS-22) were used. For the frequency analysis of categorical variables across the groups, chi-square test was used and student t tests was used to compare the differences of continuous variables., Results: In radiographic assessment, TLK (thoracolumbar kyphosis), LL (lumbar lordosis), PT (pelvic tilt), C7 SVA (sagittal vertical axis) in both groups improved significantly after surgery (p <  0.05). However, LL, PT, C7SVA improved at postoperative 1 month in the group II were not maintained at the ultimate postoperative follow-up. In clinical assessment, preoperative Oswestry disability index (ODI, %) and all SRS-22 subscores of the group I and II were not different (p > 0.05). There were significant differences between the groups at the ultimate follow-up in ODI (- 25.6 vs - 12.1, p <  0.001), SRS total score (%) (28 vs 20, p = 0.037), function subscore (1.4 vs 0.7, p = 0.016), and satisfaction subscore (1.6 vs 0.6, p < 0.001)., Conclusion: Osteoarthritic knee with KLG 3 or 4 have a negative influence on maintaining postoperative spinal sagittal alignment, balance, and the clinical outcomes achieved immediately by posterior instrumentation and fusion for lumbar degenerative disease., Trial Registration: This study was retrospectively registered with approval by the institutional review board (IRB) of our institution (approval number: 2018-11-007).

Background: Spinal surgery holds a higher chance of unpredicted postoperative medical complications among orthopedic surgeries. Several studies have analyzed the risk factors for diverse postoperative medical complications, but the majority investigated incidences of each complication qualitatively. Among gastrointestinal complications, reports regarding postoperative ileus were relatively frequent. However, risk factors or incidences of hepatobiliary complications have yet to be investigated. The purpose of this study was to examine the incidence of gastrointestinal complications after spinal surgery, quantitatively analyze the risk factors of frequent complications, and to determine cues requiring early approaches., Methods: In total, 234 consecutive patients who underwent spinal fusion surgery performed by one senior doctor at our institute in one-year period were retrospectively enrolled for analyses. The primary outcomes were presence of paralytic ileus, elevated serum alanine transaminase (ALT) and aspartate transaminase (AST) levels, and elevated total bilirubin levels. Univariate logistic regression analyses of all variables were performed. In turn, significant results were reanalyzed by multivariate logistic regression. The variables used were adjusted with age and gender., Results: Gastrointestinal complications were observed in 15.8% of patients. Upon the risk factors of postoperative ileus, duration of anesthesia (odds ratio [OR], 1.373; P = 0.015), number of fused segments (OR, 1.202; P = 0.047), and hepatobiliary diseases (OR, 2.976; P = 0.029) were significantly different. For elevated liver enzymes, men (OR, 2.717; P = 0.003), number of fused segments (OR, 1.234; P = 0.033), and underlying hepatobiliary (OR, 2.704; P = 0.031) and rheumatoid diseases (OR, 5.021; P = 0.012) had significantly different results. Lastly, risk factors for total bilirubin elevation were: duration of anesthesia (OR, 1.431; P = 0.008), number of fused segments (OR, 1.359; P = 0.001), underlying hepatobiliary diseases (OR, 3.426; P = 0.014), and thoracolumbar junction involving fusions (OR, 4.134; P = 0.002) compared to lumbar spine limited fusions., Conclusion: Patients on postoperative care after spinal surgery should receive direct attention as soon as possible after manifesting abdominal symptoms. Laboratory and radiologic results must be carefully reviewed, and early consultation to gastroenterologists or general surgeons is recommended to avoid preventable complications., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2020 The Korean Academy of Medical Sciences.)

Lumbar interbody fusion (LIF) is an effective and popular surgical procedure for the management of various spinal pathologies, especially degenerative diseases. Currently, LIF can be performed with posterior, transforaminal, anterior, and lateral approaches by open surgery or minimally invasive surgery (MIS). Each technique has its own advantages and disadvantages. In general, posterior LIF is a well-established procedure with good fusion rates and low complication rates but is limited by the possibility of iatrogenic injury to the neural structures and paraspinal muscles. Transforaminal LIF is frequently performed using an MIS technique and has an advantage of reducing these iatrogenic injuries. Anterior LIF (ALIF) can restore the disk height and sagittal alignment but has inherent approach-related challenges such as visceral and vascular complications. Lateral LIF and oblique LIF are performed using an MIS technique and have shown postoperative outcomes similar to ALIF; however, these approaches carry a risk of injury to psoas, lumbar plexus, and vascular structures. Herein, we provide a detailed description of the surgical procedures of each LIF technique. We shall then consider the pearls and pitfalls, as well as propose surgical indications and contraindications based on the available evidence in the literatures.

Objective: To compare the radiologic union rates between autogenous iliac crest bone graft (ICBG) and local bone graft in 1- to 3-level lumbar fusion., Methods: We reviewed 178 consecutive patients who underwent 1- to 3-level lumbar fusion surgery because of lumbar spinal stenosis. Fusion status of the anterior or posterior column was evaluated by plain radiographs obtained at 24 months postoperatively. If at least either the anterior or posterior column was fused, that segment was regarded as having achieved fusion and was termed segment union. The definition of overall union was achieving union of all segments in a single patient., Results: For each ICBG group and local bone graft group, fusion rate of the anterior and posterior column, and rate of the segments and overall union at postoperative 2 years were not different between the groups, regardless of surgery level. In the overall union rate according to the fusion level, the ICBG group showed constant overall fusion rate according to the fusion level (i.e., 96.9%, 96.9%, and 93.1% for 1-, 2-, and 3-level fusion), but tended to decrease with increasing level in the local bone graft group (100%, 95.8%, and 85.7% for 1-, 2-, and 3-level fusion, respectively) without statistically significant differences., Conclusions: The union rate of 3-level fusion was not inferior to those of 1- or 2-level fusion in both ICBG and local bone graft patients. Local bone graft could be regarded as an adequate option for not only 1- or 2-level lumbar fusion but also 3-level lumbar fusion surgery., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objective: Few studies have addressed that dynamic sagittal imbalance can develop distal to the spinal fusion and cause sagittal malalignment, unlike proximal junctional kyphosis (PJK) in the proximal portion. The purpose of this study was to investigate risk factors between the 2 different types of postoperative sagittal imbalance after long fusion to the sacrum for the treatment of degenerative sagittal imbalance (DSI)., Methods: Eighty patients who had undergone surgical correction for DSI were included. Radiographic measurements included spinopelvic parameters on whole-spine plain radiographs and degeneration of paravertebral muscles on MRI. Univariate and multivariate analyses for clinical and radiological factors were conducted for respective risk factors. In subgroup analyses, the 2 different types of postoperative sagittal imbalance were directly compared., Results: Forty patients (50%) developed postoperative sagittal imbalance; of these patients, 22 (55.0%) developed static proximal kyphosis from PJK, and 18 patients (45.0%) developed dynamic sagittal imbalance without PJK. The independent risk factors in proximal kyphosis were greater postoperative pelvic tilt (HR 1.11) and less change in sacral slope (SS) (HR 1.09), whereas there were more fusion levels (HR 3.11), less change in SS (HR 1.28), and less change in thoracic kyphosis (HR 1.26) in dynamic sagittal imbalance. Directly compared with the proximal kyphosis group, dynamic sagittal imbalance was more commonly found in patients who had less correction of sagittal parameters as well as fatty atrophy of the paravertebral muscles. Clinical outcomes in the dynamic sagittal imbalance group were superior to those in the proximal kyphosis group., Conclusions: Optimal correction of sagittal alignment should be considered in long instrumented fusion for DSI, because insufficient correction might cause one of 2 different types of postoperative sagittal imbalance at different sites of decompression. Dynamic sagittal imbalance compared with proximal kyphosis was significantly associated with less correction of sagittal alignment, in conjunction with more fusion levels and degeneration of the paravertebral muscles.

Purpose: Authors assumed that the stability of iliac screw (IS) fixation could affect the development of proximal junctional kyphosis (PJK). The purpose of this study was to analyze the relationship between IS loosening and PJK after long fusion surgery for adult spinal deformity (ASD)., Methods: Sixty-eight ASD patients (6 males, 62 females; mean age, 68.1 years) who underwent long fusion surgery with IS fixation were reviewed. The incidence and risk factors of IS loosening were investigated. The relationship between IS loosening and PJK was also analyzed., Results: IS loosening and PJK appeared in 33 and 19 patients, respectively. The median time for IS loosening and PJK to develop was 6.0 months (range 1.3-59.2) and 9.1 months (range 1.3-73.2), respectively. PJK developed in patients without IS loosening more frequently than in patients with IS loosening. PJK did not develop in 28 patients who presented with IS loosening first. IS loosening developed 5 months postoperatively in those 28 patients, whereas IS loosening was present 11 months postoperatively in 4 patients who presented with PJK first. Preoperative PT (OR = 1.091) and IS loosening (OR = 0.343) were significantly related with the development of PJK. IS loosening was significantly associated with postoperative PI-LL > 10° (OR = 0.957), postoperative SVA (OR = 1.023), and postoperative PT (OR = 1.072)., Conclusion: Postoperative sagittal malalignment should be avoided to prevent IS loosening and PJK. IS loosening occurred earlier than PJK and seemed to affect the development of PJK. This relationship supports the hypothesis that distal stability of long constructs may increase proximal junctional stress., Level of Evidence: III. These slides can be retrieved under Electronic Supplementary Material.

Objective: The purpose of this study was to investigate the rate of and the risk factors for surgery-related complications demonstrated on radiography after pedicle subtraction osteotomy (PSO) for thoracolumbar kyphosis in patients with ankylosing spondylitis (AS)., Methods: The authors retrospectively reviewed the medical records of 230 consecutive patients with thoracolumbar kyphosis due to AS who had undergone 1-level PSO at a single institution in the period from 2010 to 2017. The causes of surgery-related complications were divided into two types: surgical/technical failure and mechanical failure., Results: The patients consisted of 20 women and 210 men, with an average age of 43.4 years. The average follow-up period was 39.0 months. The preoperative sagittal vertical axis was 18.5 ± 69.3 cm, which improved to 4.9 ± 4.6 cm after PSO. Of the 77 patients (33.5%) who experienced minor or major surgery-related complications, 56 had complications related to surgical/technical failure (overall incidence 24.3%) and 21 had complications related to mechanical failure (overall incidence 9.1%). Fourteen patients (6.1%) underwent reoperation. However, among the 77 patients with complications, the rate of revision surgery was 18.2%. The most common radiological complications were as follows: sagittal translation in 24 patients, coronal imbalance in 20, under-correction in 8, delayed union in 8, and distal junctional failure and kyphosis in 8. The most common causes of reoperation were coronal imbalance in 4 patients, symptomatic malposition of pedicle screws in 3, and distal junctional failure in 3. Delayed union was statistically correlated with posterior sagittal translation (p = 0.007)., Conclusions: PSO can provide acceptable radiographic outcomes for the correction of thoracolumbar kyphosis in patients with AS. However, a high incidence of surgery-related complications related to mechanical failure and surgical technique can develop. Thorough radiographic investigation before and during surgery is needed to determine whether complete ossification occurs along the anterior and posterior longitudinal ligaments of the spine.

Objective: We sought to compare the radiologic outcomes for different distal fusion levels in a rigid curve with major thoracolumbar and lumbar (TL/L) adolescent idiopathic scoliosis (AIS) using rod derotation (RD) with direct vertebral rotation (DVR) after pedicle screw instrumentation (PSI)., Methods: This study finally enrolled 28 patients who were diagnosed with AIS in rigid curve with major TL/L curves, treated by PSI with RD and DVR and with a minimum 2-year follow-up. Patients were divided into 2 groups, L3 and L4, on the basis of the distal fusion level at the lowest instrumented vertebra (LIV) of L3 or L4., Results: There was no significant difference in TL/L curve, thoracic (minor), and compensatory (caudal) curves between the L3 and L4 groups either postoperatively (P = 0.162, 0.426, and 0.762, respectively) or at the last follow-up (P = 0.952, 0.620, and 0.562, respectively). The overall prevalence of unsatisfactory results was 42.9% (12/28 patients). The prevalence of unsatisfactory results was 61.1% (11/18) in the L3 group and 10% (1/10) in the L4 group, which was significantly different (P < 0.05)., Conclusions: Unsatisfactory results occurred more often in the L3 group than in the L4 group, and unsatisfactory results had significant influence on progression of TL/L and distal compensatory curves. Such progression was closely correlated with deteriorating LIV disk angle in the L3 group. Therefore if the curve is rigid, LIV should be extended to L4 to avoid the adding-on phenomenon in the treatment of major TL/L AIS using RD with DVR after PSI., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Study Design: This was a retrospective comparative study., Objective: The main objective of this article was to evaluate the clinical and radiologic efficacies of minimally invasive lateral lumbar interbody fusion (LLIF) for clinical adjacent segment pathology (ASP)., Summary of Background Data: Minimally invasive techniques have been increasingly applied for spinal surgery. No report has compared LLIF with conventional posterior lumbar interbody fusion for clinical ASP., Methods: Forty patients undergoing LLIF with posterior fusion (hybrid surgery) were compared with 40 patients undergoing conventional posterior lumbar interbody fusion (posterior surgery). The radiologic outcomes including indirect decompression in hybrid surgery group, and clinical outcomes such as the Oswestry Disability Index (ODI) and Visual Analog Scale (VAS) were assessed. Postoperative major complications and reoperations were also compared between the 2 groups., Results: Correction of coronal Cobb's angle and segmental lordosis in the hybrid surgery were significantly greater postoperatively (2.8 vs. 0.9 degrees, P=0.012; 7.4 vs. 2.5 degrees, P=0.009) and at the last follow-up (2.4 vs. 0.5 degrees, P=0.026; 4.8 vs. 0.8 degrees, P=0.016) compared with posterior surgery. As regards indirect decompression of the LLIF, significant increases in thecal sac (83.4 vs. 113.8 mm) and foraminal height (17.8 vs. 20.9 mm) were noted on postoperative magnetic resonance imaging. Although postoperative back VAS (4.1 vs. 5.6, P=0.011) and ODI (48.9% vs. 59.6%, P=0.007) were significantly better in hybrid surgery, clinical outcomes at the last follow-up were similar. Moreover, intraoperative endplate fractures developed in 17.7% and lower leg symptoms occurred in 30.0% of patients undergoing hybrid surgery., Conclusions: Hybrid surgery for clinical ASP has advantages of segmental coronal and sagittal correction, and indirect decompression compared with conventional posterior surgery. However, LLIF-related complications such as endplate fracture and lower leg symptoms also developed. LLIF should be performed considering advantages and approach-related complications for the clinical ASP.

Case: A 73-year-old man with instrumented fusion of L3-4-5 underwent the removal of previous pedicle screws and posterior instrumented fusion of L1-2-3. The solid dorsal fusion mass of L3-5 was identified intraoperatively and preoperatively. At 3 years after the second surgery, he presented with abrupt radiating pain in the left leg. Plain radiographs showed a collapse of the intervertebral disc space, and magnetic resonance imaging showed disc herniation of L3-4., Conclusions: Disc herniation even in solid fused segments may occur. Removal of pedicle screws and cranial extension of interbody fusion may increase the intradiscal stress associated with physiologic cantilever motion of the disc.

Effects of anti-osteoporosis medications such as anti-resorptive and anabolic agents on healing of osteoporotic spinal fracture were retrospectively investigated. The use of anabolic agent significantly enhanced fracture healing, reduced progressive collapse, and presented good pain relief. These findings suggest that proper selection of medication could improve initial management of acute osteoporotic spinal fractures (OSFs)., Introduction: Although anti-osteoporosis medications have beneficial effects on prevention of osteoporotic spinal fractures (OSFs), few studies have compared effects of medications on fracture healing following OSFs. Therefore, the purpose of this study was to elucidate the effects of different anti-osteoporosis medications on radiological and clinical outcomes after acute OSFs., Methods: A total of 132 patients diagnosed with acute OSFs were enrolled and allocated into three groups [group I (n = 39, no anti-osteoporosis medication), group II (n = 66, bisphosphonate), and group III (n = 27, parathyroid hormone (PTH)]. Radiological parameters including magnetic resonance (MR) classification, occurrence of intravertebral cleft (IVC), and clinical outcomes such as numerical rating scale (NRS) and Oswestry disability index were assessed. Risk analyses for IVC and progressive collapse were done along the related factors and medication type., Results: IVC sign was observed in 30 patients. The rate of IVC sign was lower in group III (7.4%) than that in group I (20.5%) or group II (30.3%), although the difference was not statistically significant. Moreover, the degree of NRS improvement was better in group III than that in group I or group II (5.7 vs. 3.1 vs. 3.5, p < 0.001). On multiple regression analysis, mid-portion type fracture in MR classification was a significant risk factor for progressive OSFs. The use of PTH showed significant lower incidences of occurrence of IVC (odds ratio (OR) = 0.160) and increase in height loss (OR = 0.325)., Conclusions: Different anti-osteoporosis medications presented different clinical and radiological results after acute OSFs. The use of anabolic agent significantly enhanced fracture healing, reduced progressive collapse, and presented better clinical outcomes. Proper selection of medication might improve initial management of acute OSFs.

Background: The optimal choice of antibiotics is challenging in culture-negative pyogenic spondylitis (PS). The empiric use of glycopeptides is suggested depending on various risk factors, although clinical data are sparse. This study aimed to analyze the clinical characteristics and outcomes of patients with culture-negative PS and evaluate the effect of empiric glycopeptide use on clinical outcomes in these patients., Materials and Methods: Data on the characteristics, treatment, and outcomes of 175 patients diagnosed with PS were retrospectively obtained from the electronic database of a tertiary referral hospital from 2009 to 2016. Patients with negative culture results were grouped by the duration of glycopeptide treatment: glycopeptide therapy <28 days (Group A) and glycopeptide therapy ≥28 days (Group B)., Results: Of 89 patients with negative culture results, 78 were included in the analysis (Group A, n = 66; Group B, n = 12). The mean age of patients with negative culture results was 65.5 years, and 52.6% were male. The median follow-up duration was 573 (interquartile range [IQR], 83 - 1,037) days. The duration of intravenous glycopeptide therapy was 0.0 (IQR, 0.0 - 0.0) days and 55.5 (IQR, 37.0 - 75.7) days for Groups A and B, respectively. Patients who used glycopeptide longer empirically (Group B) had more commonly undergone a previous spinal procedure, including surgery ( P = 0.024). The length of hospitalization, erythrocyte sedimentation rate, and C-reactive protein level were significantly higher in Group B compared with those in Group A ( P <0.001, P <0.001, and P = 0.006, respectively). Regarding treatment modalities, patients in Group B underwent surgery more frequently ( P = 0.017). The duration of parenteral antibiotic treatment was longer in Group B ( P <0.001). Recurrence was noted in 7 patients (9.0%), and the recurrence rate was not significantly different between the 2 groups (Group A, 5/66 [7.6%]; Group B, 2/12 [16.7%]; P = 0.293)., Conclusion: The recurrence rate among patients with culture-negative PS was not different based on the duration of empiric glycopeptide use. However, considering the small sample size and heterogeneity of our study population, we suggest that it is reasonable to administer glycopeptide antibiotics in these patients depending on clinical risk factors. Further large-scale prospective studies are needed to obtain more evidence for appropriate antibiotic treatment., Competing Interests: No conflicts of interest., (Copyright © 2019 by The Korean Society of Infectious Diseases and Korean Society for Antimicrobial Therapy.)

Objective: To analyze the effects of direct vertebral rotation (DVR) on radiologic outcomes in the treatment of thoracic adolescent idiopathic scoliosis after selective thoracic fusion with pedicle screw instrumentation., Methods: Adolescent idiopathic scoliosis patients with single thoracic curves (n = 110) treated by selective thoracic fusion with a minimum of 2 years of follow-up were retrospectively analyzed. The patients were separated into 2 groups: non-DVR (n = 63) and DVR (n = 47)., Results: There was a significant difference in fused segments between the non-DVR and DVR groups (P < 0.001). There was also a significant difference in main thoracic curve postoperatively (P = 0.001) and at the last follow-up (P = 0.006) between the non-DVR and DVR groups. However, there was no significant difference in proximal thoracic and lumbar curves postoperatively (proximal thoracic curve: P = 0.186; lumbar curve: P = 0.155) and at the last follow-up (proximal thoracic curve: P = 0.250; lumbar curve: P = 0.060) between the 2 groups. Significant improvements in the lowest instrumented vertebra tilt and disc angle were noted but then slight deteriorations in such were observed during the follow-up period in the non-DVR group. The prevalence of unsatisfactory results was 20.6% (13 of 63) in the non-DVR group and 19.1% (9 of 47) in the DVR group, with no significant difference (P = 0.522)., Conclusions: For correcting single thoracic adolescent idiopathic scoliosis by selective thoracic fusion with pedicle screw instrumentation, the addition of DVR to the surgical procedure showed comparable radiologic outcomes compared with non-DVR procedures., (Copyright © 2019 Elsevier Inc. All rights reserved.)