Midterm Outcomes of Muscle-Preserving Posterior Lumbar Decompression via Sagittal Splitting of the Spinous Process: Minimum 5-Year Follow-up

Background@#To overcome several disadvantages of conventional laminectomy for degenerative lumbar spinal stenosis (DLSS), several types of minimally invasive surgery have been developed. The purpose of the present study was to report the clinical and radiological mid-term outcomes of spinous process-splitting decompression (SPSD) for DLSS. @*Methods@#Seventy-three consecutive patients underwent SPSD between September 2014 and March 2016. Of these, 42 (70 segments) who had at least 5 years of follow-up were analyzed retrospectively. The visual analog scale for back pain and leg pain, Oswestry disability index, and walking distance without resting were scored to assess clinical outcomes at the preoperative and final follow-up. A subgroup analysis was performed according to the union status of the split spinous processes (SPs). For radiological outcomes, slip in the neutral position as a static parameter, anterior flexion-neutral translation, and posterior extension-neutral translation as a dynamic parameter were measured before and at the final follow-up after surgery. Spinopelvic parameters were also measured. Reoperation rate at the index levels was investigated, and predictive risk factors for reoperation were evaluated using multivariate logistic regression. Survival analysis was performed with reoperation as the endpoint to estimate the longevity of the SPSD for DLSS. @*Results@#All clinical outcomes improved significantly at the final follow-up compared to those at the initial visit (p < 0.05). The clinical outcomes did not differ according to the union status of the split SP. There were no cases of definite segmental instability and no significant changes in the static or dynamic parameters after surgery. Sacral slope and lumbar lordosis increased, and pelvic tilt decreased significantly at the follow-up (p < 0.05), despite no significant change in the sagittal vertical axis. The mean longevity of the procedure before the reoperation was 82.9 months. Five patients (11.9%) underwent reoperation at a mean of 52.2 months after the SPSD. There were no significant risk factors for reoperation; however, the preoperative severity of foraminal stenosis had an odds ratio of 7.556 (p = 0.064). @*Conclusions@#SPSD for DLSS showed favorable clinical and radiological outcomes at the mid-term follow-up. SPSD could be a good surgical option for treating DLSS.

The Feasibility of Multiple Fixation Points in C2

Methods@#We used 1.0-mm interval computed tomographic scan images of 100 patients (50 men and 50 women) and screw trajectory simulation software. The diameter of all screws was set at 3.5 mm, considering its common usage in real surgery. The anatomical feasibility of placing both pedicle and laminar screws on the same side was evaluated. For all feasible sides, the three-dimensional distance between the screw entry points was measured. @*Results@#In 85% of cases, both pedicle and laminar screws could be placed on both sides, allowing for the insertion of 4 screws. In 11% of cases, 2 screws could be placed on one side, while only 1 screw was feasible on the other side, resulting in the placement of 3 screws. In all 181 sides where both types of screws could be inserted, the distance between their entry points exceeded 16.1 mm, which was sufficient to prevent the collision between the screw heads. @*Conclusions@#C2 vertebra can accommodate three (11%) or four (85%) screws in 96% of cases.

A Novel Trajectory of C7 Laminar Screws Determined Using Three-Dimensional Computed Tomography and Surgical Simulation Software: Comparison with a Pre-existing Trajectory

Methods@#Computed tomographic scans of a total of 50 male and 50 female patients were utilized. The placement of C7 laminar screws was activated employing the new and old trajectories. The success rate, the causes of failure, and the maximum allowable length of each trajectory were compared. @*Results@#Employing the new trajectory, the success rates of the unilaminar and bilaminar screws were 93% and 83%, respectively, which were significantly better than the old trajectory (80%, p<0.0001 and 70%, p=0.0003). The most prevalent cause of failure was laminar cortical breach followed by facet joint violation. The new trajectory also offered significantly longer maximum allowable screw length in unilaminar (32.5±4.3 mm vs. 26.5±2.6 mm, p<0.001), bilaminar cephalic (29.5±3.8 mm vs. 25.9±2.6 mm, p<0.0001) and bilaminar caudal (33.1±2.6 mm vs. 25.8±3.1 mm, p<0.001) screws than the old trajectory. With the new and old trajectories, 70% vs. 6% of unilaminar, 60% vs. 2% of bilaminar caudal, and 32% vs. 4% of bilaminar cephalic screws could be protracted perfectly into the corresponding lateral mass without any laminar cortical or facet joint violation (p<0.0001). @*Conclusions@#The novel trajectory possesses a substantially higher success rate, longer maximum allowable screw length, and higher chance to be extended into the lateral mass (a condition known as a lamino-lateral mass screw) than the old trajectory.

The Use of High-Density Pedicle Screw Construct with Direct Vertebral Derotation of the Lowest Instrumented Vertebra in Selective Thoracic Fusion for Adolescent Idiopathic Scoliosis: Comparison of Two Surgical Strategies

Methods@#We reviewed consecutive patients with Lenke 1 AIS who underwent STF from 2000 to 2017. The patients were divided into two groups based on the surgical strategy used: low-density (LD) construct without DVR of the LIV (LD group) versus HD construct with DVR of the LIV (HD group). We collected data on the patient’s demographic characteristics, skeletal maturity, operative data, and measured radiological parameters in the preoperative and final follow-up radiographs. The occurrence of adding-on (AO) and coronal decompensation was also determined. @*Results@#In this study, 72 patients (five males and 67 females) with a mean age of 14.1±2.3 years were included. No significant differences in the demographics, skeletal maturity, and Lenke type distribution were observed between the two groups; however, the follow-up duration was significantly longer in the LD group (64.3±25.7 months vs. 40.7±22.2 months, p <0.001). The HD group had significantly shorter fusion segments (7.1±1.3 vs. 8.5±1.2, p <0.001) and a more proximal LIV level (12.1±0.9 vs. 12.7±1.0, p =0.009). In the radiological measurements, the improvement of LIV+1 rotation (Nash–Moe scale) was significantly larger in the HD group (0.53±0.51 vs. 0.21±0.41, p =0.008). AO and decompensation occurred in 7 (9.7%) and 4 (5.6%) patients in the HD and LD groups, respectively, without any significant difference between the two groups. @*Conclusions@#In this study, the HD group had a significantly shorter fusion level and a more proximal LIV than the LD group; however, the two groups had similar curve correction and adverse radiological outcome rates.

Anterior Thigh Pain Following Minimally Invasive Oblique Lateral Interbody Fusion: Multivariate Analysis from a Prospective Case Series

Background@#Oblique lateral interbody fusion (OLIF) involves the antepsoas approach and psoas major muscle (PMM) retraction to insert the interbody cage orthogonally. Therefore, OLIF is often associated with postoperative anterior thigh pain (ATP) on the approach side. However, there is limited evidence on the nature and risk factors of ATP following OLIF. @*Methods@#Consecutive patients who planned to undergo minimally invasive OLIF and percutaneous pedicle screw instrumentation for lumbar degenerative diseases were prospectively enrolled. The visual analog scale (VAS) for ATP was recorded, and a pain map was drawn daily from the operation day to postoperative day 7 in all patients. We also prospectively collected the preoperative and intraoperative data to identify the risk factors associated with ATP. Radiologically, the total cross-sectional area (CSA), retraction length, and retraction CSA of PMM were measured from the preoperative T2-weighted axial magnetic resonance imaging scans at the L4–5 intervertebral disc level. The patients were stratified into two groups based on the experience of ATP with a VAS score of ≥ 7 at any time point. Additionally, a binary logistic regression analysis was performed to identify the associated factors. @*Results@#The current prospective study included 92 patients (31 men, 61 women) with a mean age of 70.4 years (range, 56–86 years), who underwent OLIF at our institution. The left-side approach was used in 73 patients (79.3%), while 19 (20.7%) underwent a right-side approach. Sixty-five of the total patients (70.6%) experienced approach-side ATP to any extent during postoperative 0–7 days following OLIF. The mean pain VAS (4.4 ± 2.1) and the prevalence (57.6%) were highest at postoperative 2 days. On postoperative day 7, there were 19 patients (20.7%) who complained of residual ATP with a mean VAS of 2.6 ± 1.8. In the multivariate analysis, the PMM retraction length was significantly associated with ATP of VAS ≥ 7 (adjusted odds ratio, 2.316; p = 0.044). @*Conclusions@#In this study, we prospectively collected and analyzed the ATP and associated factors following OLIF and identified the PMM retraction length as a potential independent risk factor for severe ATP in the immediate postoperative period following OLIF.

Radiographic Factors for Progression of Thoracolumbar Kyphosis in Achondroplasia Patients after Walking Age: A Generalized Estimating Equation Analysis

Background@#This study aimed to analyse the trends in changes of radiologic parameters according to age to predict factors affecting the progression of thoracolumbar kyphosis (TLK). @*Methods@#Records of patients with achondroplasia were retrospectively reviewed from July 2001 to December 2020. We measured imaging parameters (T10–L2 angle, sagittal Cobb angle, width, height, and number of wedge vertebrae, and apical vertebral translation [AVT]) of 81 patients with radiographically confirmed TLK. Based on the angle on X-ray taken in 36 months, 49 patients were divided into the progression group (P group, TLK angle ≥ 20°) and resolution group (R group, TLK angle < 20°). The mean values between the groups were compared using Student t-test, and the pattern of changes in each radiologic parameter according to age was analysed using a generalized estimating equation. @*Results@#Some imaging parameters showed significant differences according to age between P group and R group: T10–L2 angle (p < 0.001), sagittal Cobb angle (p < 0.001), AVT (p = 0.025), percentage of wedge vertebral height (WVH) (p = 0.018), and the number of severely deformed wedge vertebral bodies (anterior height less than 30% of posterior) (p = 0.037). Regarding the percentage of wedge vertebral widths (superior and inferior endplates), the difference between the two groups did not significantly increase with age, but regardless of age, it was higher in P group than in R group. @*Conclusions@#The difference in the TLK angle between P group and R group of the achondroplasia patients gradually increased with age. Among the imaging parameters, AVT and WVH could be factors that ultimately affect the exacerbation of kyphosis as the difference between the groups increased significantly over time.

Surgical Causes of Significant Intraoperative Neuromonitoring Signal Changes in Three-Column Spinal Surgery

Methods@#Multimodality IONM data, including somatosensory-evoked potentials (SSEP) and motor-evoked potentials (MEP), were reviewed in 64 patients who underwent three-column spinal surgery from 2011 to 2015. Surgical procedures included posterior vertebral column resection, pedicle subtraction osteotomy, total en bloc spondylectomy, piecemeal spondylectomy, and corpectomy with laminectomy (n=27) in three cervical, 34 thoracic, and 31 lumbar procedures. @*Results@#Significant IONM signal changes occurred in 11 of 64 (17.1%) patients. SSEP and MEP were changed in 11 patients. Postoperative neurologic deterioration occurred in 54.5% (6 of 11) of the patients, and two of them were permanent. There was no postoperative neurologic deterioration in patients without significant signal change. Suspected causes of IONM data changes are as follows: adhesion/tethering, translation, contusion, and perfusion. @*Conclusions@#Based on the results of this study, to enhance neurologic safety in three-column spinal surgery, surgeons should pay attention to protect the spinal cord from mechanical insult, especially when the spinal column was totally destabilized during surgery, and not to compromise perfusion to the spinal cord in close cooperation with a neurologist and anesthesiologist.

Medical Care Utilization Behavior for the Diagnosis and Treatment of Spine Disease: A Questionnairebased Study of Orthopaedic Spine Center Outpatients at a Tertiary Educational Hospital

Objectives@#The purpose of our study was to investigate medical care utilization behavior and the conceptions of disease treatment among spine disease patients.Summary of Literature Review: Analyzing the medical care utilization behavior and conceptions of disease treatment among spine disease patients is important. @*Materials and Methods@#A survey was administered to 500 first-time patients who visited the spine center of a tertiary educational hospital from May 2017 to August 2019. @*Results@#A total of 479 valid responses were analyzed. A minority of patients (16.1%) visited the tertiary educational hospital without having previously visited a private hospital. Spinal procedures and surgery were considered negatively by 52.6% of respondents, and 14.8% of patients reported negative perceptions of orthopedic drugs. @*Conclusions@#Extensive efforts will be required to improve unreasonable medical utilization behavior by changing patients’ incorrect knowledge and beliefs about hospitals, diseases, and treatments.

Volumetric Assessment of Fusion Mass and Its Clinical Correlations in Posterior Lumbar Interbody Fusion Depending on the Type of Bone Graft

Objectives@#This study was conducted to analyze associations between the volume of the fusion mass and clinical outcomes 1 year after posterior lumbar interbody fusion (PLIF).Summary of Literature Review: No study has investigated associations between the size of the fusion mass and clinical outcomes after PLIF. @*Materials and Methods@#The volume of the fusion mass and its clinical correlations after PLIF were analyzed in all patients and in subgroups. When a sufficient amount of local bone was available for grafting, only local bone without a graft extender was used (LbG group, n=20). If an inadequate amount of local bone was present for grafting, a local bone graft with porous hydroxyapatite bone chips was used (LbHa group, n=20). The same amount of demineralized bone matrix was used in both groups. The primary outcome was the relationship between the size of the fusion mass and clinical outcomes in all patients 1 year after surgery. The secondary outcome was a comparison of the size of the fusion mass and clinical outcomes by group. @*Results@#The volume of the fusion mass was not correlated with any clinical outcomes 1 year after surgery, either in the overall group of patients or in the subgroup analysis. @*Conclusions@#The volume of the interbody fusion mass was not related to any clinical outcomes 1 year after surgery. Furthermore, in cases with an insufficient amount of local bone for grafting, porous hydroxyapatite could be a relatively good alternative as a graft extender.

Treatment Strategy for Impending Instability in Spinal Metastases

Background@#Determining surgical management of a spinal metastasis is difficult owing to the involvement of multiple factors.The spinal instability neoplastic score (SINS) system is a reliable tool to evaluate instability in spinal metastases. The intermediate SINS (scores 7–12) indicates impending instability, which makes it difficult to determine the proper treatment strategy. In this study, we aimed to compare the initial status and treatment outcomes of a conservative group versus an operative group among patients with spinal metastases with an intermediate SINS of 7–12. Further, we evaluated the time for conversion to surgery in patients who had initially undergone conservative treatment and identified the factors associated with the conversion. @*Methods@#Among the patients with a spinal metastasis with an intermediate SINS of 7–12 from May 2013 to December 2017, those who were followed up for more than 12 months were enrolled in this study. Patients with signs of a neurologic deficit or cord compression at the initial diagnosis were excluded. Finally, 79 patients (47 in the initially conservative group and 32 in the initially operative group) were enrolled in this study. The performance status, Tomita score, and Tokuhashi score were assessed for group comparison. Components of SINS, the Bilsky grade, and radiosensitivity of tumor were evaluated to determine factors associated with conversion to surgery. @*Results@#Average follow-up was 20.9 months (range, 12–46 months). The demographic variables, primary cancer type, and performance status were not significantly different between the 2 groups. However, the Tomita score was lower in the initially operative group (p = 0.006). The 1-year treatment outcome assessed based on the change in performance status and vertebral height collapse showed a tendency to deteriorate less in the initially operative group. The rate of conversion to surgery in the initially conservative group was 33% in the first year, after which there was little change in the incidence of conversion. When vertebral body collapse was less than 50% or the tumor was located in the semi-rigid region (T3–T10), the need for conversion to surgery increased statistically significantly (p = 0.039 and p = 0.042, respectively). @*Conclusions@#The rate of conversion to surgery in initially conservatively treated patients was about 33% in the first year. When a tumor is located in T3–T10 and less than 50% vertebral body collapse is present, surgery may be the better choice than conservative treatment.

Treatment Strategy for Metastatic Spinal Tumors: A Narrative Review

Metastatic spinal tumors are common, and their rising incidence can be attributed to the expanding aging population and increased survival rates among cancer patients. The decision-making process in the treatment of spinal metastasis requires a multidisciplinary approach that includes medical and radiation oncology, surgery, and rehabilitation. Various decision-making systems have been proposed in the literature in order to estimate survival and suggest appropriate treatment options for patients experiencing spinal metastasis. However, recent advances in treatment modalities for spinal metastasis, such as stereotactic radiosurgery and minimally invasive surgical techniques, have reshaped clinical practices concerning patients with spinal metastasis, making a demand for further improvements on current decision-making systems. In this review, recent improvements in treatment modalities and the evolution of decision-making systems for metastatic spinal tumors are discussed.

Restoration of the Spinous Process Following Muscle-Preserving Posterior Lumbar Decompression via Sagittal Splitting of the Spinous Process

BACKGROUND: In lumbar spinal stenosis, spinous process-splitting decompression has demonstrated good clinical outcomes with preservation of the posterior ligamentous complex and paraspinal muscles in comparison to conventional laminectomy, but the radiological consequence and clinical impact of the split spinous processes have not been fully understood. METHODS: Seventy-three patients who underwent spinous process-splitting decompression were included. The bone union rate and pattern were evaluated by computed tomography performed 6–18 months after surgery and compared among subgroups divided according to the number of levels decompressed and the extent of spinous process splitting. The bone union pattern was classified into three categories: complete union, partial union, and nonunion. The visual analog scale (VAS) score, Oswestry disability index (ODI), and walking distance assessed both before and 24–36 months after surgery were compared among subgroups divided according to the union pattern of the split spinous process. RESULTS: Overall, the rates of complete union, partial union, and nonunion were 51.7%, 43.2%, and 5.1%, respectively. In the subgroup with partial splitting of the spinous process, the rates were 85.7%, 14.3%, and 0%, respectively; those of the subgroup with total splitting of the spinous process were 32.9%, 59.2%, and 7.9%, respectively. With single-level decompression, a higher rate of union was observed compared with multilevel decompression. The VAS, ODI, and walking distance were significantly improved after surgery and did not differ according to the degree of union of the split spinous process. CONCLUSIONS: We found that the single-level operation and partial splitting of the spinous process were favourable factors for obtaining complete restoration of the posterior bony structure of the lumbar spine in spinous process-splitting decompression.

Clinical Significance of Resection Type and Margin following Surgical Treatment for Primary Sarcoma of the Spine: A Multi-Center Retrospective Study

OBJECTIVES@#To analyze oncological outcomes according to the resection type and surgical margin following surgical treatment for primary spinal sarcoma.SUMMARY OF LITERATURE REVIEW: Previous studies using registry databases have shown that surgery and negative margins were associated with improved survival for primary spinal sarcoma. However, few studies have comprehensively analyzed the clinical significance of the resection type and surgical margin for the oncological outcomes of this rare malignancy.@*MATERIALS AND METHODS@#We retrospectively reviewed consecutive patients who underwent surgical resection for primary spinal sarcoma between 1997 and 2016 at two tertiary medical centers. Overall survival and the occurrence of local recurrence and distant metastasis were compared between the groups using Kaplan-Meier curve analysis and the log-rank test.@*RESULTS@#Thirty-three patients (21 males,12 females) with a mean age of 45.1 years and a median follow-up of 36 months were included. There were 13 (39.4%) chondrosarcomas, 12 (36.4%) osteosarcomas, and eight different histological diagnoses. The cohort was categorized into four groups: 1) total en bloc resection with a negative margin (n=12; 36.4%), 2) total en bloc resection with a positive margin: (n=5; 15.2%), 3) total piecemeal resection (n=12; 36.4%), and 4) subtotal resection (n=4; 12.1%). Total en bloc resection with a negative margin was associated with improved overall survival (p=0.030) and less distant metastasis (p=0.025) and local recurrence (p=0.004).@*CONCLUSIONS@#Achieving a negative margin through total en bloc resection, although technically demanding, improves oncological outcomes in primary spinal sarcoma.

Clinical Significance of Resection Type and Margin following Surgical Treatment for Primary Sarcoma of the Spine: A Multi-Center Retrospective Study / 대한척추외과학회지

STUDY DESIGN: A retrospective multi-center study.OBJECTIVES: To analyze oncological outcomes according to the resection type and surgical margin following surgical treatment for primary spinal sarcoma.SUMMARY OF LITERATURE REVIEW: Previous studies using registry databases have shown that surgery and negative margins were associated with improved survival for primary spinal sarcoma. However, few studies have comprehensively analyzed the clinical significance of the resection type and surgical margin for the oncological outcomes of this rare malignancy.MATERIALS AND METHODS: We retrospectively reviewed consecutive patients who underwent surgical resection for primary spinal sarcoma between 1997 and 2016 at two tertiary medical centers. Overall survival and the occurrence of local recurrence and distant metastasis were compared between the groups using Kaplan-Meier curve analysis and the log-rank test.RESULTS: Thirty-three patients (21 males,12 females) with a mean age of 45.1 years and a median follow-up of 36 months were included. There were 13 (39.4%) chondrosarcomas, 12 (36.4%) osteosarcomas, and eight different histological diagnoses. The cohort was categorized into four groups: 1) total en bloc resection with a negative margin (n=12; 36.4%), 2) total en bloc resection with a positive margin: (n=5; 15.2%), 3) total piecemeal resection (n=12; 36.4%), and 4) subtotal resection (n=4; 12.1%). Total en bloc resection with a negative margin was associated with improved overall survival (p=0.030) and less distant metastasis (p=0.025) and local recurrence (p=0.004).CONCLUSIONS: Achieving a negative margin through total en bloc resection, although technically demanding, improves oncological outcomes in primary spinal sarcoma.

The Spinal Instability Neoplastic Score (SINS) as a Surgical Decision-Making Tool for the Treatment of Spine Metastasis

OBJECTIVES@#To investigate the potential clinical use of the spinal instability neoplastic score (SINS) for determining the surgical strategy, especially regarding the need for anterior support.SUMMARY OF LITERATURE REVIEW: The SINS seems to enable an improved qualitative and quantitative assessment of spinal instability in patients with spinal metastasis.@*MATERIALS AND METHODS@#We retrospectively reviewed 69 consecutive patients who underwent surgical treatment for spinal metastasis. We assessed the patients' preoperative status with respect to each component of the SINS. Multiple logistic regression was performed to calculate odds ratios (ORs) representing the associations among SINS, age, Eastern Cooperative Oncology Group performance status, modified Tokuhashi score, as well as the preoperative Nurick grade variables and reconstruction of the anterior spinal column.@*RESULTS@#Among the 6 items in the SINS, those indicating the degree of collapse and alignment had significantly higher scores in those who underwent corpectomy and anterior support (p<0.001). Multiple logistic regression revealed that the total SINS was the only factor significantly associated with predicting whether anterior support should be performed (adjusted OR=1.595). Receiver operating characteristic (ROC) curve analysis suggested that a cut-off value of 10 points on the SINS scale could be used to decide whether anterior support following corpectomy should be performed (AUC=0.706).@*CONCLUSIONS@#The SINS, insofar as it assesses the degree of collapse and alignment, is a potentially useful tool for determining the surgical strategy in patients with spinal metastasis, especially for deciding upon the necessity of additional anterior support procedures.

Radiographic and Clinical Outcomes of Robot-Assisted Posterior Pedicle Screw Fixation: Two-Year Results from a Randomized Controlled Trial

PURPOSE: We prospectively assessed the early radiographic and clinical outcomes (minimum follow-up of 2 years) of robot-assisted pedicle screw fixation (Robot-PSF) and conventional freehand pedicle screw fixation (Conv-PSF). MATERIALS AND METHODS: Patients were randomly assigned to Robot-PSF (37 patients) or Conv-PSF (41 patients) for posterior interbody fusion surgery. The Robot-PSF group underwent minimally invasive pedicle screw fixation using a pre-planned robot-guided screw trajectory. The Conv-PSF underwent screw fixation using the freehand technique. Radiographic adjacent segment degeneration (ASD) was measured on plain radiographs, and clinical outcomes were measured using visual analogue scale (VAS) and Oswestry disability index (ODI) scores regularly after surgery. RESULTS: The two groups had similar values for radiographic ASD, including University California at Los Angeles grade, vertebral translation, angular motion, and loss of disc height (p=0.320). At final follow-up, both groups had experienced significant improvements in back VAS, leg VAS, and ODI scores after surgery (p < 0.001), although inter-group differences were not significant for back VAS (p=0.876), leg VAS (p=0.429), and ODI scores (p=0.952). In the Conv-PSF group, revision surgery was required for two of the 25 patients (8%), compared to no patients in the Robot-PSF group. CONCLUSION: There were no significant differences in radiographic ASD and clinical outcomes between Robot-PSF and Conv-PSF. Thus, the advantages of robot-assisted surgery (accurate pedicle screw insertion and minimal facet joint violation) do not appear to be clinically significant.

The Spinal Instability Neoplastic Score (SINS) as a Surgical Decision-Making Tool for the Treatment of Spine Metastasis / 대한척추외과학회지

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To investigate the potential clinical use of the spinal instability neoplastic score (SINS) for determining the surgical strategy, especially regarding the need for anterior support. SUMMARY OF LITERATURE REVIEW: The SINS seems to enable an improved qualitative and quantitative assessment of spinal instability in patients with spinal metastasis. MATERIALS AND METHODS: We retrospectively reviewed 69 consecutive patients who underwent surgical treatment for spinal metastasis. We assessed the patients' preoperative status with respect to each component of the SINS. Multiple logistic regression was performed to calculate odds ratios (ORs) representing the associations among SINS, age, Eastern Cooperative Oncology Group performance status, modified Tokuhashi score, as well as the preoperative Nurick grade variables and reconstruction of the anterior spinal column. RESULTS: Among the 6 items in the SINS, those indicating the degree of collapse and alignment had significantly higher scores in those who underwent corpectomy and anterior support (p<0.001). Multiple logistic regression revealed that the total SINS was the only factor significantly associated with predicting whether anterior support should be performed (adjusted OR=1.595). Receiver operating characteristic (ROC) curve analysis suggested that a cut-off value of 10 points on the SINS scale could be used to decide whether anterior support following corpectomy should be performed (AUC=0.706). CONCLUSIONS: The SINS, insofar as it assesses the degree of collapse and alignment, is a potentially useful tool for determining the surgical strategy in patients with spinal metastasis, especially for deciding upon the necessity of additional anterior support procedures.

Prognosis of Single Spinal Metastatic Tumors: Predictive Value of the Spinal Instability Neoplastic Score System for Spinal Adverse Events

STUDY DESIGN: This was a retrospective cohort study. PURPOSE: We evaluated the predictive value of the Spinal Instability Neoplastic Score (SINS) system for spinal adverse events (SAEs) in patients with single spinal metastatic tumor. OVERVIEW OF LITERATURE: The SINS system was developed to assess spinal instability in patients with single metastatic spinal tumor. However, the system’s potential predictive value for SAEs has been partially studied. METHODS: This system was applied to a retrospective cohort of 78 patients with single spinal metastatic tumors. The patients underwent surgical treatment and were postoperatively followed up for at least 2 years or until death. The attribution of each score and total SINS to SAE (vertebral compression fracture [VCF] and spinal cord compression [SCC]) occurrence was assessed using the Cox proportional hazards model. RESULTS: SAEs occurred on average 7 months after diagnosis of spinal metastasis. The mean survival rate post diagnosis was 43 months. Multivariate analysis using the Cox proportional hazards model revealed that the pain (p=0.029) and spinal alignment (p=0.001) scores were significantly related to VCF occurrence, whereas the pain (p=0.008) and posterolateral involvement (p=0.009) scores were related to SCC occurrence. CONCLUSIONS: Among the components of the SINS system, while pain and spinal alignment showed a significant association with VCF occurrence, pain and posterolateral involvement showed association with SCC occurrence.

Prevalence of Frailty in Patients with Osteoporotic Vertebral Compression Fracture and Its Association with Numbers of Fractures

PURPOSE: To assess the association between frailty and osteoporotic vertebral compression fracture (OVCF) and to evaluate the relationship between numbers of OVCFs and frailty. MATERIALS AND METHODS: We enrolled 760 subjects, including 59 patients (with OVCF) and 701 controls (without OVCF). Successful matching provided 56 patient-control pairs. We analyzed principal clinical and demographic information, which included sex, age, height, weight, body mass index (BMI), variable frailty phenotypes, and Oswestry Disability Index (ODI) and EuroQol 5-dimension questionnaire (EQ-5D) scores. The association between frailty and OVCF was ascertained. In addition, the degrees of disability and quality of life attributable to frailty were determined. RESULTS: The prevalence of frailty was significantly higher in the OVCF group than in the control group (p < 0.001). Most of the frailty phenotypes, such as exhaustion, physical inactivity, slowness, and handgrip strength, were also significantly observed in the OVCF group. Within the OVCF group, the participants with frailty had significantly higher disability and lower quality of life than those in a robust state (p < 0.001 for ODI and EQ-5D). In addition, the multivariate logistic regression analysis demonstrated that the patients with low BMI [odds ratio (OR)=0.704; 95% confidence interval (CI), 0.543–0.913] and ≥3 fractures (OR=9.213; 95% CI, 1.529–55.501) within the OVCF group were associated with higher odds of frailty. CONCLUSION: The present study showed significant relationships between frailty and OVCF, severity of symptoms, and disability induced by OVCF. Furthermore, frailty could be a causal and/or resulting factor of OVCFs.

Prevalence of Neuropathic Pain and Patient-Reported Outcomes in Korean Adults with Chronic Low Back Pain Resulting from Neuropathic Low Back Pain

STUDY DESIGN: A noninterventional, multicenter, cross-sectional study. PURPOSE: We investigated the prevalence of neuropathic pain (NP) and patient-reported outcomes (PROs) of the quality of life (QoL) and functional disability in Korean adults with chronic low back pain (CLBP). OVERVIEW OF LITERATURE: Among patients with CLBP, 20%–55% had NP. METHODS: Patients older than 20 years with CLBP lasting for longer than three months, with a visual analog scale (VAS) pain score higher than four, and with pain medications being used for at least four weeks before enrollment were recruited from 27 general hospitals between December 2014 and May 2015. Medical chart reviews were performed to collect demographic/clinical features and diagnosis of NP (douleur neuropathique 4, DN4). The QoL (EuroQoL 5-dimension, EQ-5D; EQ-VAS) and functional disability (Quebec Back Pain Disability Scale, QBPDS) were determined through patient surveys. Multiple linear regression analyses were performed to compare PROs between the NP (DN4≥4) and non-NP (DN4 < 4) groups. RESULTS: A total of 1,200 patients (females: 65.7%; mean age: 63.4±13.0 years) were enrolled. The mean scores of EQ-5D, EQ-VAS, and QBPDS were 0.5±0.3, 55.7±19.4, and 40.4±21.1, respectively. Among all patients, 492 (41.0%; 95% confidence interval, 38.2%–43.8%) suffered from NP. The prevalence of NP was higher in male patients (46.8%; p < 0.01), in patients who had pain based on radiological and neurological findings (59.0%; p < 0.01), and in patients who had severe pain (49.0%; p < 0.01). There were significant mean differences in EQ-5D (NP group vs. non-NP group: 0.4±0.3 vs. 0.5±0.3; p < 0.01) and QBPDS (NP group vs. non-NP group: 45.8±21.2 vs. 36.3±20.2; p < 0.01) scores. In the multiple linear regression, patients with NP showed lower EQ-5D (β=−0.1; p < 0.01) and higher QBPDS (β=7.0; p < 0.01) scores than those without NP. CONCLUSIONS: NP was highly prevalent in Korean patients with CLBP. Patients with CLBP having NP had a lower QoL and more severe dysfunction than those without NP. To enhance the QoL and functional status of patients with CLBP, this study highlights the importance of appropriately diagnosing and treating NP.