Frailty is not an independent risk factor for worse clinical outcomes in lumbar spinal surgery: a prospective cohort study.

PURPOSE: Recently, many studies revealed that frailty affects unfavorably on postoperative outcomes in lumbar spinal diseases. This study aimed to investigate the relationship between frailty and clinical outcomes while identifying risk factors associated with worse clinical outcomes following lumbar spinal surgery. METHODS: From March 2019 to February 2021, we prospectively enrolled eligible patients with degenerative lumbar spinal diseases requiring surgery. Frailty was assessed preoperatively. To identify the impact of frailty on lumbar spinal diseases, clinical outcomes, which were measured with patient-reported outcomes (PROs) and postoperative complications, were compared according to the frailty. PROs were assessed preoperatively and one year postoperatively. In addition, risk factors for preoperative and postoperative worse clinical outcomes were investigated. RESULTS: PROs were constantly lower in the frail group than in the non-frail group before and after surgery, and the change of PROs between before and after surgery and postoperative complications were not different between the groups. In addition, frailty was a persistent risk factor for postoperative worse clinical outcome before and after surgery in lumbar spinal surgery. CONCLUSION: Frailty persistently affects the clinical outcome negatively before and after surgery in lumbar spinal surgery. However, as the change of the clinical outcome is not different between the frail group and the non-frail group, it is difficult to interpret whether the frail patients are vulnerable to the surgery. In conclusion, frailty is not an independent risk factor for worse clinical outcome in lumbar spinal surgery.

Quantitative Analysis of the Effect of Stereotactic Radiosurgery for Postoperative Residual Cervical Dumbbell Tumors: A Multicenter Retrospective Cohort Study.

OBJECTIVE: Stereotactic radiosurgery (SRS) has been performed for spinal tumors. However, the quantitative effect of SRS on postoperative residual cervical dumbbell tumors remains unknown. This study aimed to quantitatively evaluate the efficacy of SRS for treating postoperative residual cervical dumbbell tumors. METHODS: We retrospectively reviewed cases of postoperative residual cervical dumbbell tumors from 1995 to 2020 in 2 tertiary institutions. Residual tumors underwent SRS (SRS group) or were observed with clinical and magnetic resonance imaging (MRI) follow-up (observation group). Tumor regrowth rates were compared between the SRS and observation groups. Additionally, risk factors for tumor regrowth were analyzed. RESULTS: A total of 28 cervical dumbbell tumors were incompletely resected. Eight patients were in the SRS group, and 20 in the observation group. The mean regrowth rate was not significantly lower (p = 0.784) in the SRS group (0.18 ± 0.29 mm/mo) than in the observation group (0.33 ± 0.40 mm/mo). In the multivariable Cox regression analysis, SRS was not a significant variable (hazard ratio [HR], 0.57; 95% confidence interval [CI], 0.18-1.79; p = 0.336). CONCLUSION: SRS did not significantly decrease the tumor regrowth rate in our study. We believe that achieving maximal resection during the initial operation is more important than postoperative adjuvant SRS.

Are there advantages in cervical intrafacetal fusion (cIFF) with minimal posterolateral fusion (PLF) compared to conventional PLF in posterior cervical fusion?

Objective: We propose that cervical intrafacetal fusion (cIFF) using bone chip insertion into the facetal joint space additional to minimal PLF is a supplementary fusion method to conventional posterolateral fusion (PLF). Methods: Patients who underwent posterior cervical fixation accompanied by cIFF with minimal PLF or conventional PLF for cervical myelopathy from 2012 to 2023 were investigated retrospectively. Radiological parameters including Cobb's angles and C2-7 sagittal vertical axis (SVA) were compared between two groups. In cIFF with minimal PLF group, cIFF location and PLF location were carefully divided, and the fusion rates of each location were analyzed by CT scan. Results: Among enrolled 46 patients, 31 patients were in cIFF group, 15 in PLF group. The postoperative change of Cobb's angle in 1-year follow-up in cIFF with minimal PLF group and conventional PLF group were 0.1˚ ± 4.0 and -9.7˚ ± 8.4 respectively which was statistically lower in cIFF with minimal PLF group (p=0.022). Regarding the fusion rate in cIFF with minimal PLF group in postoperative 6 months, the rates was achieved in 267 facets (98.1%) in cIFF location, and 244 facets (89.7%) in PLF location (p<0.001). Conclusion: Postoperative sagittal alignment was more preserved in cIFF with minimal PLF group compared with conventional PLF group. Additionally, in cIFF with minimal PLF group, the bone fusion rate of cIFF location was higher than PLF location. Considering the concerns of bone chip migration onto the spinal cord and relatively low fusion rate in PLF method, applying cIFF method using minimized PLF might be a beneficial alternative for posterior cervical decompression and fixation.

Unilateral Pediculectomy and Reduction with Short-Segment Pedicle Screw Fixation for Thoracolumbar Burst Fracture: A Case Series.

BACKGROUND: This study aimed to evaluate the efficacy of unilateral pediculectomy and reduction with short-segment pedicle screw fixation for thoracolumbar burst fracture. METHODS: We retrospectively reviewed patients who underwent a unilateral pediculectomy and reduction with short-segment fixation and interbody fusion for thoracolumbar burst fracture. The unilateral pediculectomy created sufficient space to approach the ventral side of the spinal cord for removing bone fragments and insertion of an interbody cage to correct kyphosis. Lumbar lordosis (LL), pelvic incidence (PI) minus LL, and segmental Cobb angle were measured at 3 time points: preoperatively, postoperatively, and final follow-up. Furthermore, sagittal vertical axis (SVA) was measured to assess global sagittal balance at the final follow-up. RESULTS: A total of 10 patients, with a mean age of 39.8 ± 21.0, underwent the surgical procedure. All patients had a thoracolumbar injury classification and severity score > 5. The mean follow-up period was 15.8 ± 13.9 months. The mean postoperative LL (46.0 ± 5.8) was significantly higher (P = 0.008) than the preoperative measurement (32.8 ± 8.2). The mean postoperative PI minus LL (2.2 ± 8.4) was not significantly lower (P = 0.051) than preoperative measurement (15.4 ± 12.6). The mean postoperative segmental Cobb angle (11.4 ± 8.4) was significantly higher (P < 0.001) than the preoperative measurement (-11.6 ± 10.9). At the final follow-up, the mean sagittal vertical axiswas 10.0 ± 28.8 mm. CONCLUSIONS: Unilateral pediculectomy and reduction with short-segment fixation and interbody fusion served as an efficient surgical method for thoracolumbar burst fracture.

Comparison of the Efficacy of an Anchored Cage with Unidirectional and Bidirectional Screw Fixation in Single-Level Cervical Discectomy and Fusion Surgery.

AIM: To compare, and to analyze the clinical and radiological signs between bidirectional and unidirectional screw fixation in single level cervical discectomy and fusion surgery. MATERIAL AND METHODS: We retrospectively reviewed the data collected from 90 patients and divided them into the upper or lower spine fixation group (unidirectional) and the normal upper and lower spine fixation group (bidirectional). The patients' demographic data and preoperative and postoperative (24 months) clinical outcomes were collected. Pre- and postoperative (immediately and at 3, 6, 12, and 24 months) changes in the segmental angle in the operating field (SA), cervical lordosis, C2-7 sagittal vertical axis, and active disc height (aDH) were evaluated. We also compared the rate of fusion and muscle size change between the groups. RESULTS: The operation time in the bidirectional screw fixation group was significantly longer than that in the unidirectional screw fixation group ( > 6 min; p=0.03). There was no significant difference between the two groups in radiographic parameters before and immediately after surgery. From 3 months postoperatively, the unidirectional group had significantly higher SA and aDH than the bidirectional group (p=0.03). The fusion rate was higher in the bidirectional screw fixation group than in the unidirectional group, but this was not statistically significant (97% vs. 88%, p=0.07). CONCLUSION: The results of this study suggest that unidirectional screw fixation surgery can be useful as it has been associated with simple surgery, short surgery time, and maintenance of the lordotic curvature of SA and disc height.

GSK-3ß and ß-Catenin Signaling Pathway is Involved in Myofibroblast Transition of Ligamentum Flavum in Lumbar Spinal Stenosis Patients.

STUDY DESIGN: Histologic analysis of the ligamentum flavum (LF) in the lumbar spine. OBJECTIVE: The objective of this study is to investigate the levels of glycogen synthase kinase-3ß (GSK-3ß) and ß-catenin in the LF tissue of patients with lumbar spinal stenosis (LSS). SUMMARY OF BACKGROUND DATA: The hypertrophy of the LF is the primary cause of the progression of LSS. Recently, Wnt signaling has been proposed as one of the molecular processes contributing to LF hypertrophy. GSK-3ß and ß-catenin are recognized to play a crucial part in the control of this signaling pathway. MATERIALS AND METHODS: From May 2020 to July 2022, LF from 51 LSS patients (LSS group) and 18 lumbar disc herniation patients (control group) were prospectively collected during surgery. Histologic analysis was investigated to confirm the progression of LF fibrosis. The levels of α-smooth muscle actin, phosphorylation of GSK-3ß (p-GSK-3ß; inactive form), and ß-catenin were analyzed in LF with Western blot analysis to reveal the GSK-3ß/ß-catenin signaling pathway. Continuous variables are expressed as mean±SD and compared using the student t test. Categorical variables are compared using the χ 2 test or Fisher exact test, as appropriate. To determine the association between p-GSK-3ß and LF thickness, the Pearson correlation coefficient was calculated based on the results of Western blot analysis. RESULTS: The LSS group was older and had thicker LF than the controls. The LSS group showed increased collagen fiber and cellularity than the controls. The levels of α-smooth muscle actin, p-GSK-3ß, and ß-catenin in the LF of the LSS group were significantly higher than that of the control group. There was a strong positive correlation between p-GSK-3ß (Ser9) level and LF thickness in LSS patients ( r =0.69, P =0.01). CONCLUSION: This research proposes a molecular mechanism for the pathogenesis of LF hypertrophy in LSS. Specifically, GSK-3ß/ß-catenin signaling appears to be related to LF hypertrophy in LSS and a positive correlation exists between p-GSK-3ß level and LF thickness. LEVEL OF EVIDENCE: Level 3.

Effectiveness of intraoperative table modification for achieving lumbar lordosis in multilevel lumbar fusion surgery: a propensity score-matched study.

BACKGROUND: In multilevel posterior lumbar interbody fusion (PLIF) with posterior screw fixation, obtaining sufficient lumbar lordosis (LL) is difficult, especially in patients with osteoporosis. We performed intraoperative table modification (TM) using gravitational dropping of the patient's lumbar spine, to improve restoration of LL. METHODS: We retrospectively reviewed the medical records of patients who underwent three- or four-level PLIF between 2005 and 2019. One hundred eleven patients were enrolled, with 96 patients receiving non-TM-PLIF and 15 patients receiving TM-PLIF. Radiological parameters, including segmental lordosis (SL), LL, sacral slope (SS), pelvic incidence, and pelvic tilt, were measured. Clinical outcomes were measured using a visual analogue scale (VAS) for the back and leg preoperatively and at the last follow-up. Additionally, the correlation between the bone mineral density (BMD) and the radiological parameters was calculated for TM-PLIF. We performed propensity score matching between the groups to control the baseline difference. RESULTS: We found a statistically better correction between immediate and last follow-up postoperative SL (p = 0.04), as well as between preoperative and last follow-up SL (p < 0.01) in the TM-PLIF group compared to that in the non-TM-PLIF group. VAS for the back and leg were not significantly different between the two groups. Additionally, the efficacy of lordosis correction in the TM-PLIF group showed a statistically significant negative correlation between BMD and the SS change both before and after the surgery (rho = -0.60, p = 0.02). CONCLUSION: Whilst further study is required to conclusively establish its efficacy, TM-PLIF (table modification using gravitational dropping) shows potential advantages for restoring and maintaining LL in multilevel lumbar fusion, particularly in cases with low BMD.

Antibiotics Prophylaxis for Endoscopic Endonasal Approach for Skull Base Tumor Surgery: A Meta-Analysis.

BACKGROUND: The regimen of prophylactic antibiotic for endoscopic endonasal skull base surgery (EE-SBS) varies considerably depending on surgeons and their institutes. The purpose of the present meta-analysis is to assess the effect of antibiotic regimens on EE-SBS surgery for anterior skull base tumor. METHODS: The PubMed, Embase, Web of Science, and Cochrane clinical trial databases were systematically searched through October 15, 2022. RESULTS: The 20 included studies were all retrospective. The studies included a total of 10,735 patients who underwent EE-SBS for skull base tumor. The proportion of patients with postoperative intracranial infection across all 20 studies was 0.9% (95% confidence interval [CI] 0.5%-1.3%). The proportion of postoperative intracranial infection in the multiple antibiotics group did not show statistically significant difference to that of the single antibiotic agent group (proportion: 0.6%, 95% CI 0%-1.4% vs. proportion: 1%, 95% CI 0.6%-1.5%, respectively, P = 0.39). The ultra-short duration maintenance group showed lower incidence of postoperative intracranial infection, although it did not reach statistical significance (ultra-short group: 0.7%, 95% CI 0.5%-0.9%; short duration: 1.8%, 95% CI 0.5%-3%; and long duration: 1%, 95% CI 0.2%-1.9%, P = 0.22) The combination of the multiple antibiotics group did not show meaningful low incidence of postoperative intracranial infection (antibiotics combination group: 0.6%, 95% CI 0%-1.4%; cefazolin single group: 0.8%, 95% CI 0%-1.6%; and single antibiotics other than cefazolin: 1.2%, 95% CI 0.7%-1.7%, P = 0.22). CONCLUSIONS: Multiple antibiotics did not show superiority compared with single antibiotic agent. Also, long maintenance duration of antibiotics did not reduce the incidence of postoperative intracranial infection.

Comparison of the Efficacy of Romosozumab and Teriparatide for the Management of Osteoporotic Vertebral Compression Fractures.

OBJECTIVE: Romosozumab is increasingly employed to manage osteoporosis. However, no studies have analyzed its effects on recent osteoporotic vertebral compression fractures (OVCFs). Therefore, this study aimed to evaluate the efficacy of romosozumab compared with teriparatide in managing OVCFs. METHODS: The electronic medical records of postmenopausal patients with recent OVCFs who were administered romosozumab or teriparatide for one year from March 2018 to August 2022 were retrospectively reviewed. We compared the 2 groups for demographics, radiological outcomes (compression ratio, Cobb angle, and bone mineral density [BMD]), and clinical outcomes (Numerical Rating Scale [NRS] for back pain). RESULTS: Fifty-five patients with OVCFs, 32 patients treated with romosozumab and 23 with teriparatide, were included in this study. The change of BMD (g/cm2) values was significantly higher (p = 0.016) in the romosozumab (0.04 ± 0.06) than in the teriparatide group (0.00 ± 0.08) in the femur total. Furthermore, in subgroup analysis, the change of BMD (g/cm2) values in the lumbar spine was significantly higher (p = 0.016) in the romosozumab (0.12 ± 0.06) than in the teriparatide group (0.07 ± 0.06) in the lumbar spine. The decrease in NRS was significantly higher (p = 0.013) in the romosozumab (6.6 ± 2.0) than in the teriparatide group (5.5 ± 2.1). However, there was no significant difference in radiologic outcomes between the 2 groups. CONCLUSION: Our findings suggest that romosozumab may be more effective than teriparatide in treating OVCFs in postmenopausal females, particularly in improving BMD and reducing back pain as measured by NRS.

Management of Cerebrospinal Fluid Leakage by Pump-Regulated Volumetric Continuous Lumbar Drainage Following Anterior Cervical Decompression and Fusion for Ossification of the Posterior Longitudinal Ligament.

OBJECTIVE: Cerebrospinal fluid (CSF) leakage is a major concern related to anterior cervical decompression and fusion for ossification of the posterior longitudinal ligament (OPLL). We propose a management algorithm for CSF leakage following anterior cervical decompression and fusion for OPLL involving the use of pump-regulated volumetric continuous lumbar drainage. METHODS: We retrospectively reviewed patients who underwent anterior cervical decompression and fusion for OPLL and were managed with the proposed algorithm between March 2018 and July 2022. The proposed management algorithm for CSF leakage by pump-regulated volumetric continuous lumbar drainage was as follows. On exposure of the arachnoid membrane with or without CSF leakage, a dural sealant patch was applied to manage the dural defect. In case of persistent CSF leakage despite application of the dural sealant patch, patients underwent pump-regulated volumetric continuous lumbar drainage. RESULTS: Fifty-one patients were included in the study. CSF leakage occurred in 14 patients. Of these 14 patients, 9 patients underwent lumbar drain insertion according to the proposed management algorithm. Successful resolution of CSF leakage was observed in 8 of the 9 patients who underwent lumbar drainage. All patients were encouraged to ambulate without concern of CSF overdrainage due to gravity, because it could be avoided with pump-regulated volumetric continuous CSF drainage. Therefore, complications associated with absolute bed rest or CSF overdrainage were not observed. CONCLUSION: The proposed management algorithm with pump-regulated volumetric continuous lumbar drainage showed safety and efficacy for management of CSF leakage following anterior decompression and fusion for OPLL.

Sacropelvic Fixation for Adult Deformity Surgery Comparing Iliac Screw and Sacral 2 Alar-Iliac Screw Fixation: Systematic Review and Updated Meta-Analysis.

OBJECTIVE: Two commonly used techniques for spinopelvic fixation in adult deformity surgery are iliac screw (IS) and sacral 2 alar-iliac screw (S2AI) fixations. In this article, we systematically meta-analyzed the complications of sacropelvic fixation for adult deformity surgery comparing IS and S2AI. METHODS: The PubMed, Embase, Web of Science, and Cochrane clinical trial databases were systematically searched until March 29, 2023. The proportion of postoperative complications, including implant failure, revision, screw prominence, and wound complications after sacropelvic fixation, were pooled with a random-effects model. Subgroup analyses for the method of sacropelvic fixation were conducted. RESULTS: Ten studies with a total of 1,931 patients (IS, 925 patients; S2AI, 1,006 patients) were included. The pooled proportion of implant failure was not statistically different between the IS and S2AI groups (21.9% and 18.9%, respectively) (p = 0.59). However, revision was higher in the IS group (21.0%) than that in the S2AI group (8.5%) (p = 0.02). Additionally, screw prominence was higher in the IS group (9.6%) than that in the S2AI group (0.0%) (p < 0.01), and wound complication was also higher in the IS group (31.7%) than that in the S2AI group (3.9%) (p < 0.01). CONCLUSION: IS and S2AI fixations showed that both techniques had similar outcomes in terms of implant failure. However, S2AI was revealed to have better outcomes than IS in terms of revision, screw prominence, and wound complications.

Meta-Analysis on the Effect of Hypothermia in Acute Spinal Cord Injury.

OBJECTIVE: Acute spinal cord injury (SCI) can result in debilitating motor, sensory, and autonomic dysfunction. As a treatment option, therapeutic hypothermia has been researched to inadequate pharmaceutical treatment, except for methylprednisolone. In this article, we systematically meta-analyzed to clarify the effect of hypothermia in acute SCI on neurological outcomes. METHODS: The PubMed, Embase, Web of Science, and Cochrane clinical trial databases were systematically searched until June 30, 2022. The proportion of cases with improved neurological status after hypothermia in acute SCI were pooled with a random-effects model. Subgroup analyses for the method of hypothermia and injury level were conducted. RESULTS: Eight studies with a total of 103 patients were included. Hypothermia in acute SCI improved neurological function by 55.8% (95% confidence interval [CI]: 39.4%-72.1%). The subgroup analysis revealed that the pooled proportion of cases showing neurological improvement was higher with systemic hypothermia (70.9%) (95% CI, 14.9%-100%) than with local hypothermia (52.5%) (95% CI, 40.4%-64.5%), although the subgroup difference was not statistically significant (p = 0.53). Another subgroup analysis revealed that the proportion of cases with neurological improvement did not differ statistically between the cervical spine (61.4%) (95% CI, 42.2%-80.6%) and thoracic spine injury groups (59.4%) (95% CI, 34.8%-84.0%) (p = 0.90). CONCLUSION: This meta-analysis identified that more than 50% of patients showed neurological improvement after hypothermia following acute SCI in general. A multicenter, randomized, double-blind study with larger sample size is necessary to validate the findings further.

Should cervicothoracic junctions be avoided in long cervical posterior fusion surgery? Analysis of clinical and radiologic outcomes over two years.

PURPOSE: This study aimed to confirm the usefulness of surgery that avoids the cervicothoracic junction (CTJ) by comparing the clinical and radiographic outcomes after posterior cervical fusion at C5/6 with those at C7/T1. METHODS: Patients who underwent laminectomy and posterior cervical instrument fusion for cervical spondylotic myelopathy (CSM) from 2012 to 2019 were retrospectively reviewed and divided according to whether the end level was at C5/6 (group 1) or C7/T1 (group 2). Demographic variables and incidence of distal junctional kyphosis (DJK) were compared between the groups. Clinical outcomes (visual analog scale [VAS] score for arm and neck pain and the Neck Disability Index value) and radiologic outcomes (T1 slope, cervical lordosis, segmental lordosis, C2-7 sagittal vertical axis, T1 slope-cervical lordosis mismatch) were compared over time. RESULTS: Sixty-seven patients were included. There were 32 patients in group 1 and 35 in group 2. The VAS score for neck pain was significantly lower in group 1 than in group 2 at 2 years after surgery (p = 0.03). The C2-7 sagittal vertical axis was significantly larger in group 2 than in group 1 at 1 year and 2 years postoperatively (p = 0.04). The incidence of DJK was higher in group 2 than in group 1 (28.57% vs 9.37%, p = 0.04). CONCLUSION: This study found that when CTJs are included in the posterior cervical long fusion surgery, although it would be better than preoperation, postoperative kyphosis and consequent neck pain may progress. The results of this study advocate the concept of avoiding CTJ fusion if possible.

Surgical strategy for metastatic spinal tumor patients with surgically challenging situation.

The incidence of spinal metastasis is increasing as cancer patients live longer owing to the improvement of cancer treatments. However, traditional surgery (TS) which fixates at least 2 levels above and 2 levels below the affected vertebrae is sometimes difficult to perform as it is burdensome to the patients. In this article, we introduce our experience and strategy in treating spinal metastasis, focusing particularly on challenging cases. We retrospectively reviewed the data of 110 patients who underwent spinal surgery for metastatic spinal tumors from April 2018 to March 2020. Among them, 5 patients who received anterior approach surgery were excluded. The remaining 105 patients were enrolled. In addition to TS, we also performed cervical pedicle screw, cervicothoracic junction fixation, thoracolumbar short fixation, and decompression surgery, depending on the characteristics of the tumor. The overall survival was analyzed, and the local tumor control rate was evaluated using magnetic resonance imaging. Perioperative clinical characteristics including Spine Oncology Study Group Outcomes Questionnaire, visual analog scale, Eastern Cooperative Oncology Group performance score, and Karnofsky Performance Score were also investigated. The overall survival rate was 57.9% at 1 year, and the local tumor control rate was 81.1% after surgery. There was a statistically significant difference according to the type of the tumor in the survival analysis: the overall survival rates were 72.7% for favorable tumors and 48.6% for unfavorable tumors at 12 months after surgery (P = .04). Spine Oncology Study Group Outcomes Questionnaire, visual analog scale, Eastern Cooperative Oncology Group performance score, and Karnofsky Performance Score was improved after surgery. All surgical methods, including TS, cervical pedicle screw, cervicothoracic junction fixation, thoracolumbar short fixation, and decompression surgery, showed good clinical and radiological outcomes. Optimized surgical methods show similarly good clinical outcomes in managing spinal metastasis as TS.

Change in the Alignment and Distal Junctional Kyphosis Development after Posterior Cervical Spinal Fusion Surgery for Cervical Spondylotic Myelopathy - Risk Factor Analysis.

OBJECTIVE: This study analyzed the risk factors in patients who developed distal junctional kyphosis (DJK) after posterior cervical fusion. METHODS: We retrospectively analyzed the clinical and radiographic outcomes of 64 patients, aged ≥18 years (51 and 13 male and female patients, respectively), who underwent single-staged multilevel (3-6 levels) posterior cervical fusion surgery due to multiple cervical spondylotic myelopathy. The surgeries were performed by a single spinal surgeon between January 2012 and December 2017. Demographic data, clinical outcomes, and radiological results were collected. We divided the patients into a DJK group and a non-DJK group according to the presence of DJK and investigated the risk factors by comparing the differences between the two groups. RESULTS: Of the 64 patients, 13 developed DJK. No significant differences in clinical results were observed between the two groups before and immediately after the surgery. At the final follow-up, a higher visual analog score for neck pain was observed in the DJK group compared to the non-DJK group (p<0.01). The DJK group had a significantly lower T1 slope and a significantly higher C2-7 sagittal vertical axis (SVA) before surgery compared to the non-DJK group (p=0.03 and p<0.01, respectively). Immediately after surgery, the difference between the two groups decreased and no significant difference was observed. However, at the last followup, a significantly higher C2-7 SVA was observed in the DJK group (p<0.01). At the last follow up, there is no discrepancy in T1S-CL. In multiple logistic regression analysis, preoperative higher C2-7 SVA and preoperative lower T1 slope were identified as independent risk factors (p=0.03 and p<0.01, respectively). As a result, it was confirmed that DJK occurred along the process of returning to preoperative values. CONCLUSION: DJK can be considered to be caused by cervical misalignment due to excessive change in the surgical site in patients with low T1 slope and high C2-7 SVA before surgery. This also affects the clinical outcome after surgery. It is recommended to refrain from excessive segmental lordosis changes during multilevel cervical post fusion surgery, especially in patients with a small preoperative T1 slope and a large SVA value.

The risk factors of intracerebral hemorrhage in deep brain stimulation: does target matter?

BACKGROUND: Although deep brain stimulation (DBS) is a relatively safe and effective surgery compared with ablative surgeries, intracerebral hemorrhage (ICH) is a serious complication during DBS that could result in a fatal prognosis. We retrospectively investigated whether ICH incidence differed between patients who underwent DBS in the subthalamic nucleus (STN) and in the globus pallidus interna (GPi), together with previously identified risk factors for ICH. METHODS: We retrospectively reviewed the medical records of 275 patients (527 DBS targets) who received DBS for Parkinson's disease or dystonia from April 2001 to December 2020. In cases that developed intra- or postoperative ICH, patients were classified as asymptomatic, symptomatic with temporary neurological deficit or symptomatic with permanent neurological deficit, according to patient clinical status. RESULTS: ICH occurred in 12 procedures (2.3%) among the 527 DBS procedures (275 patients) evaluated. In multivariable logistic regression analysis, the risk factor for all cases of ICH was systolic blood pressure (BP) during surgery (cut-off value 129.4 mmHg) (OR = 1.05, 95% CI = 1.01-1.09, P = 0.023). In addition, for ICH with permanent neurological deficit, STN target site (P = 0.024) and systolic BP during surgery (cut-off value: 148.3 mmHg) (P = 0.004) were identified as risk factors in univariable analyses. CONCLUSION: Even though the risk factor for all ICH in DBS was BP during surgery, when focused on ICH evoking permanent neurological deficit, the target location as well as systolic BP during surgery proved to be related.

Benefits and Pitfalls of O-Arm Navigation in Cervical Pedicle Screw.

BACKGROUND: Cervical pedicle screw (CPS) with O-arm-based intraoperative navigation has demonstrated satisfactory results in recent studies. In this article, we introduce our experience and discuss important considerations for CPS placement with O-arm navigation. METHODS: We retrospectively reviewed the data of 51 patients with 156 pedicle screws who underwent O-arm navigated CPS from July 2020 to October 2021. The accuracy of each screw placement was evaluated at the initial screw location using intraoperative 3D reconstructed O-arm images and the final screw location using postoperative computed tomography (CT). The screw accuracy was assessed in the axial image. RESULTS: The initial accuracy of screws on intraoperative 3D reconstructed O-arm images was 93.6% (146 of 156). The accuracies of the mid-cervical level (C3, C4, C5) were relatively low (83.3%-85.0%) compared with those of C2, C6, and C7 (93.3%-100.0%) at the initial screw due to the rotation of the vertebral body. Among 10 violated screws, 5 were converted to lateral mass screws or removed intraoperatively, and the other 5 were retained because the violations were minimal. After converting the screw, the final accuracy of the screws in postoperative CT was 96.7% (146 of 151). CONCLUSIONS: CPS with O-arm navigation showed relatively low accuracy at the mid-cervical level due to vertebral rotation. However, the opportunity to convert the screw from intraoperative 3D reconstructed O-arm images is the advantage of the O-arm navigation, and it showed excellent accuracy.

Posterior Thoracic Cage Interbody Fusion Offers Solid Bone Fusion with Sagittal Alignment Preservation for Decompression and Fusion Surgery in Lower Thoracic and Thoracolumbar Spine.

OBJECTIVE: It is challenging to make solid fusion by posterior screw fixation and laminectomy with posterolateral fusion (PLF) in thoracic and thoracolumbar (TL) diseases. In this study, we report our experience and follow-up results with a new surgical technique entitled posterior thoracic cage interbody fusion (PTCIF) for thoracic and TL spine in comparison with conventional PLF. METHODS: After institutional review board approval, a total of 57 patients who underwent PTCIF (n=30) and conventional PLF (n=27) for decompression and fusion in thoracic and TL spine between 2004 and 2019 were analyzed. Clinical outcomes and radiological parameters, including bone fusion, regional Cobb angle, and proximal junctional Cobb angle, were evaluated. RESULTS: In PTCIF and conventional PLF, the mean age was 61.2 and 58.2 years (p=0.46), and the numbers of levels fused were 2.8 and 3.1 (p=0.46), respectively. Every patient showed functional improvement except one case of PTCIF. Postoperative hematoma as a perioperative complication occurred in one and three cases, respectively. The mean difference in the regional Cobb angle immediately after surgery compared with that of the last follow-up was 1.4° in PTCIF and 7.6° in conventional PLF (p=0.003), respectively. The mean durations of postoperative follow-up were 35.6 months in PTCIF and 37.3 months in conventional PLF (p=0.86). CONCLUSION: PTCIF is an effective fusion method in decompression and fixation surgery with good clinical outcomes for various spinal diseases in the thoracic and TL spine. It provides more stable bone fusion than conventional PLF by anterior column support.

Posterior Floating Laminotomy as a New Decompression Technique for Posterior Cervical Spinal Fusion Surgery.

OBJECTIVE: In the cervical spine, many surgical procedures have been developed to achieve optimal results for various disorders, including degenerative diseases, traumatic injury, and tumor. In this study, we report our experience and follow-up results with a new surgical technique for cervical spine entitled posterior floating laminotomy (PFL) in comparison with conventional laminectomy and fusion (LF). METHODS: Data for 85 patients who underwent conventional LF (n=66) or PFL (n=19) for cervical spine disorders between 2012 and 2019 were analyzed. Radiological parameters, including cervical lordosis (CL), T1 slope (T1S), segmental lordosis (SL), and C2-7 sagittal vertical axis (SVA), were measured with lateral spine X-rays. Functional outcomes, comprising the modified Japanese Orthopaedic Association (mJOA), neck disability index (NDI), and visual analog scale (VAS) scores, were also measured. For the patients who underwent PFL, postoperative magnetic resonance image (MRI) was performed in a month after the surgery, and the degree of decompression was evaluated at the T2-weighted axial image, and postoperative computed tomography (CT) was conducted immediately and 1 year after the operation to evaluate the gutter fusion. RESULTS: There was no difference in CL, T1S, SL, and C2-7 SVA between the groups but there was a difference in the preoperative and postoperative SL angles. The mean difference in the preoperative SL angle compared with that at the last follow-up was -0.3° after conventional LF and 4.7° after PFL (p=0.04), respectively. mJOA, NDI, and VAS scores showed significant improvements (p<0.05) during follow-up in both groups. In the PFL group, postoperative MRI showed sufficient decompression and postoperative CT revealed gutter fusion at 1 year after the operation. CONCLUSION: PFL is a safe surgical method which can preserve postoperative CL and achieve good clinical outcomes.