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Objective : Although several commercialized bone cements are used during percutaneous vertebroplasty (PVP) for patients with osteoporotic vertebral compression fracture (OVCF), there are no reports using domestic products from South Korea. In this study, we investigated the safety and efficacy of Spinofill® (Injecta Inc., Gunpo, Korea), a new polymethyl methacrylate product.Methods : A prospective, single-center, and single-arm clinical trial of 30 participants who underwent PVP using Spinofill® for painful thoracolumbar OVCF was performed with 6-months follow-up. Clinical and surgical outcomes included the Visual analog scale (VAS), Korean-Oswestry disability index (K-ODI), and Odom’s criteria, complication rate, and recurrence rate. Radiological outcomes were evaluated by measuring the findings of postoperative computed tomography and simple radiograph.Results : The pain of VAS (from 8.95±1.05 to 4.65±2.06, p

Cervical artificial discs (CADs) are a surgical option in selected patients with cervical spinal disc degeneration. Although CADs have been available for many years, concerns persist regarding long-term safety, durability, and implant-related failure. We report a case of nucleus herniation of a Mobi-C implant without trauma, which is a rare complication. Two years after implantation of a Mobi-C implant, a 47-year-old man presented with acute paraplegia without a history of trauma. On cervical magnetic resonance imaging, a T2-high signal intensity lesion was noted in the ventral aspect of the spinal cord at the T1-2 level. During emergent surgery, nucleus herniation of the Mobi-C was detected. After surgery, the patient could walk without assistance. Posterior herniation of the Mobi-C nucleus without trauma is a rare complication that should be considered in surgical planning and follow-up.

STUDY DESIGN Retrospective cohort study. OBJECTIVE The aim of this study was to analyze postoperative complications and recovery patterns in different modified 11-item frailty index (mFI-11) groups after lateral lumbar interbody fusion (LLIF) surgery. SUMMARY OF BACKGROUND DATA The relationship between the mFI-11 score and LLIF surgery has not been previously reported. METHODS A single-center, consecutive series of patients who underwent LLIF with at least two years of follow-up were retrospectively reviewed. Complications after LLIF surgery were recorded. Clinical outcomes, including the visual analog scale (VAS) for back/leg pain and the Oswestry Disability Index (ODI), were evaluated preoperatively and at 1 and 2 years postoperatively. The proportions of patients who achieved substantial clinical benefit (SCB) for the VAS-B, VAS-L, and ODI were also analyzed. RESULTS One hundred fifty-two patients included in the present study were grouped according to their mFI-11 score: 0 (n = 39), 0.09 (n = 69), 0.18 (n = 31), and ≥0.27 (n = 13). An mFI-11 score ≥0.27 was a significant predictor of urinary complications (adjusted odds ratio: 3.829, P = 0.013). At 2 years postoperatively, patients in all frailty categories experienced improvements in the VAS for back pain, VAS for leg pain, and ODI, without significant differences between the four groups (p = 0.182, 0.121, and 0.804, respectively). There were also no significant differences in the proportions of patients achieving SCB for back/leg pain and the ODI between the four groups (P = 0.843, 0.957, and 0.915, respectively). CONCLUSION An mFI-11 score was found to be independently associated with urologic complications in patients who underwent LLIF. Patients in all frailty categories experienced significant improvements in back pain, leg pain, and the ODI at 1 year and 2 years postoperatively. LLIF surgery may be useful for patients with high frailty index.Level of Evidence: 4.

Objective We evaluated the effect of the total psoas area index (TPAI = total psoas muscle area [cm2]/height squared [m2]) on neurological complications and clinical outcomes after lateral lumbar interbody fusion and identified the appropriate TPAI to achieve a substantial clinical benefit (SCB). Methods A consecutive series of 123 patients who had undergone single-level lateral lumbar interbody fusion at a single center with ≥2 years of follow-up were retrospectively reviewed. The patient characteristics and operative data were evaluated. The neurological complications were classified as transient and persistent symptoms. The visual analog scale score for back pain was assessed preoperatively and at 1 and 2 years postoperatively. Results The present study included 31 men and 92 women. The mean TPAI was 8.97 cm2/m2 for the men and 5.04 cm2/m2 for the women. The mean TPAI was not significantly different between the patients with and without perioperative neurological complications. Multiple logistic regression analysis showed that solid interbody fusion was the most significant factor for achieving an SCB regarding back pain in men (odds ratio [OR], 2.453; P = 0.019) and women (OR, 2.906; P = 0.042). The TPAI was one of the predictors for achieving an SCB in men (OR, 1.251; P = 0.038) and women (OR, 1.795; P = 0.023). The optimal cutoff point of the TPAI for an SCB was 8.18 cm2/m2 for the men and 4.43 cm2/m2 for the women. Conclusions The TPAI had little effect on the incidence of perioperative neurological complications. However, the TPAI was identified as one of the predictors for achieving an SCB regarding back pain.

Objective Previous literatures have demonstrated widely variable clinical results after transsacral epiduroscopic laser decompression (SELD) and the factors predicting outcomes are not yet established. Therefore, we analyzed the clinical outcome and associated predictive factors of SELD in patients with lumbar disc herniation. Methods Between 2015 and 2018, 82 patients who underwent single-level SELD and followed up at least 6 months were enrolled. The overall success rate (excellent or good results at final follow-up) was 58.5% according to Odom’s criteria. Based on this result, patients were divided to 2 groups: a favorable group (n = 48) and an unfavorable group (n = 34). A retrospective review of the baseline characteristics and clinical outcome were conducted to reveal the predictive factors. Results As expected, improvement of pain and patient satisfaction, was more favorable in the favorable group (p < 0.05). Moreover, the rate of additional procedure was lower in the favorable group (4.2%, 2 of 48 patients) than in the unfavorable group (35.3%, 12 of 34 patients) (p = 0.011). Among the various baseline characteristics, the only significant predictive factor for favorable outcome was the presence of a high-intensity zone (HIZ) on preoperative magnetic resonance imaging (50.0% [24 of 48 patients] in the favorable group vs. 11.8% [4 of 34 patients] in the unfavorable group; odds ratio, 15.67; p = 0.024). Conclusion Although SELD for lumbar disc herniation resulted in a less favorable clinical outcome than that reported in previous studies, in patients with a HIZ, SELD can be an effective minimally invasive surgery to relieve low back pain and/or leg pain.

Study design Retrospective cohort study. Objective The purpose of this study was to analyze the long-term results for patients with lumbar spinal stenosis (LSS) treated with dynamic stabilization (DS) and to consider how we can improve the results. Summary of background data Few studies have reported long-term outcomes of DS surgery for LSS with or without spondylolisthesis. Methods A single-center, single-surgeon consecutive series of LSS patients who underwent DS surgery with at least five years of follow-up were retrospectively reviewed. Twenty-seven patients were included in the LSS group and 38 patients in the spondylolisthesis group. Patient characteristics, operative data, radiographic parameters, clinical outcomes, and complications were analyzed at baseline and follow-up. Results In the LSS group, all radiographic parameters (e.g., disc height, segmental lordosis, segmental range of motion [ROM] at the index level and proximal adjacent level, global lordosis, and global ROM) were maintained well until the last follow-up. In the spondylolisthesis group, global lordosis decreased from 36.5° ± 8.2° to 32.6° ± 6.0° at the last follow-up (p = 0.039), and global ROM decreased from 22.1° ± 6.9° to 18.8° ± 7.1° at the last follow-up (p = 0.012). In both groups, back pain, leg pain, and Oswestry Disability Index scores showed significant and sustained improvements. Screw loosening occurred in three patients (11.1%) in the LSS group and five patients (13.2%) in the spondylolisthesis group. Symptomatic adjacent segment degeneration (ASD) occurred in two patients (7.4%) in the LSS group and three patients (7.9%) in the spondylolisthesis group. Conclusions Decompression and DS surgery for LSS with or without spondylolisthesis showed favorable long-term surgical outcomes with an acceptable rate of complications and ASD. However, an improved physiological DS system should be developed.Level of Evidence: 4.

STUDY DESIGN Retrospective cohort study. OBJECTIVE The aim of this study was to investigate the prognosis of symptomatic pseudarthrosis observed at 1 year after lateral lumbar interbody fusion (LLIF) surgery and to analyze the risk factors for persistent pseudarthrosis for 2 years postoperatively. SUMMARY OF BACKGROUND DATA Few articles have evaluated the prognosis of symptomatic pseudarthrosis following LLIF surgery. METHODS One hundred fifty-two patients with a minimum follow-up of 2 years were screened. Fusion status was assessed at 1 year postoperatively, and unfused segments were reevaluated at 2 years postoperatively. Dynamic x-rays and computed tomography images were acquired to evaluate the fusion status. Demographic data were evaluated to identify the risk factors associated with persistent pseudarthrosis. Clinical outcomes, including the visual analog scale (VAS) for back/leg pain and the Oswestry disability index (ODI), were evaluated preoperatively and at 1 and 2 years postoperatively. RESULTS Symptomatic pseudarthrosis was detected in 42 patients at 1 year postoperatively. Among them, 23 patients (54.8%) exhibited solid bony fusion 2 years postoperatively without further intervention. Fourteen patients (33.3%) showed asymptomatic pseudarthrosis, and the remaining five patients (11.9%) showed symptomatic pseudarthrosis. Multivariable analysis showed that diabetes (adjusted odds ratio [OR]: 2.817, P = 0.007), smoking (adjusted OR: 6.497, P = 0.008), and fusion at more than three levels (adjusted OR: 2.525, P = 0.031) were risk factors for persistent pseudarthrosis. Improvements in the VAS scores for back pain and ODI scores were significantly lower in the persistent pseudarthrosis group than in the final solid fusion group at 2 years postoperatively. CONCLUSION It is not necessary to intervene for all patients in whom symptomatic pseudarthrosis is detected at 1 year postoperatively because only 11.9% of them will show persistent symptomatic pseudarthrosis. However, early revision surgery should be considered when severe symptomatic pseudarthrosis associated with diabetes, smoking, and fusion at more than three levels is present.Level of Evidence: 4.

Some of the improvements in DH, FH, and SLL achieved intraoperatively during lateral lumbar interbody fusion surgery were lost by the postoperative 1-week follow-up. An intraoperative radiograph can predict radiographic and clinical outcomes of the 2-year follow-up. The difference between preoperative DH and intraoperative DH should be4.18 mm.Retrospective cohort study The aim of this study was to evaluate whether the intraoperatively estimated parameters, as calculated on a cross-table lateral radiograph, are maintained in an upright position at discharge and at 2 years postoperatively and to identify the appropriate disc height (DH) to achieve substantial clinical benefit. The amount of correction retained following lateral lumbar interbody fusion (LLIF) surgery had not been reported. A single-center, consecutive series of patients who underwent single-level LLIF with at least 2 years of follow-up were retrospectively reviewed. Upright standardized preoperative, 1-week, and 2-year postoperative radiographs, as well as intraoperative lateral radiographs, were analyzed for DH, foraminal height (FH), and segmental lumbar lordosis (SLL) at the index level. Clinical outcomes were compared between preoperatively and 1 week and 2 years postoperatively. In total, 89 patients were evaluated (mean follow-up, 42.8 months [range, 24–83 months]). DH decreased from 12.5 ± 2.7 mm intraoperatively to 11.7 ± 3.1 mm at 1 week postoperatively, FH decreased from 15.9 ± 3.6 mm to 15.1 ± 3.6 mm, and SLL decreased from 13.6° ± 1.7° to 12.4° ± 1.7°. A linear correlation between intraoperative and 2-year postoperative parameters was found (R2 = 0.552, 0.518, and 0.616, respectively). Clinical outcomes, including back pain, leg pain, and Oswestry Disability Index (ODI), significantly improved 2 years postoperatively. The optimal cutoff point for substantial clinical benefit thresholds for the ODI was a 4.18 mm increase in DH (sensitivity, 64.3%; specificity, 80.3%; area under the curve, 0.793; 95% confidence interval, 0.642–0.855). Some of the improvements in DH, FH, and SLL achieved intraoperatively during LLIF surgery were lost by the postoperative 1-week follow-up. An intraoperative radiograph can predict radiographic and clinical outcomes of the 2-year follow-up. The difference between preoperative DH and intraoperative DH should be4.18 mm. Level of Evidence: 4.

Objectives The purpose of this study was to evaluate surgical outcomes and complications of spinal deformity associated with neurofibromatosis type-1 (NF-1). Methods From 2012 to 2018, patients suffering from spinal deformity associated with NF-1 who underwent surgical correction were identified. Demographic data and radiographic measures were retrospectively reviewed. Pre- and postoperative whole spine radiograph images were used to determine both coronal and sagittal Cobb angles. All of patients underwent 3-dimentional computed tomographic scan and magnetic resonance imaging scan to confirm dystrophic features. For evaluation of clinical outcomes, we surveyed the pre- and postoperative scoliosis research society-22r (SRS-22r) score. Results Seven patients with spinal deformity associated with NF-1 were enrolled in this study. The mean age of patients was 29.5±1.2 years old. The mean follow-up period was 2.8±1.4 years. The apex of the deformity was located in cervicothoracic (n=1), thoracic (n=4), and lumbar region (n=2). Most patients have poor bone quality and decreased bone mineral density with average T-score of -3.5±1.0. All patients underwent surgical correction via posterior approach. The pre- and postoperative mean coronal and sagittal Cobb angle was 61.6±22.6° and 34.6±38.1°, 56.8±18.5° and 40.2±9.1°, respectively. Mean correction rate of coronal and sagittal angle was 44.7% and 23.1%. Ultimate follow-up SRS-22r score (average score, 3.9±0.4) improved comparing to preoperative score (average score, 3.3±0.9). Only one patient received revision surgery due to rod fracture. No serious complication occurred, such as neurological deficit, and viscerovascular injury. Conclusion The surgical correction of patients having spinal deformity associated with NF-1 is challenging, however the radiographic and clinical outcomes are satisfactory. The all posterior approach can be a safe and effective surgical option for patients having dystrophic curves associated with NF-1.

Objective Even if analyzed through meta-analyses or systemic reviews ensued lately, we could say that at least it is inconclusive which of the surgical or non-surgical treatment to lumbar spinal stenosis is better particularly in short to intermediate-term. This study compared non-surgical and surgical outcomes in surgical candidates for lumbar spinal stenosis (LSS). Methods Surgical candidates for LSS were prospectively screened. Patients were offered the option to be enrolled in a randomized cohort, an observational cohort, or not to participate. Patient-reported outcomes were evaluated at baseline, and at 1, 3, 6, and 12 months. The primary outcomes were measures of pain and functional outcomes such as the Korean version of the Oswestry Disability Index (K-ODI), the EuroQol 5-Dimension instrument (EQ-5D), and 36-Item Short-Form Health Survey (SF-36). Results One hundred and ten patients were enrolled in the randomized cohort and 37 patients in the observational cohort. Among them, 97 patients received non-surgical treatment, and 50 patients underwent surgical treatment. At 12 months, the non-surgical treatment group had less improvements in the primary outcome measures of back pain (mean change: non-surgery, 2.34 vs. surgery, 3.99), leg pain (2.92 vs. 3.40), K-ODI (5.12 vs. 8.31), EQ-5D utility index (0.19 vs. 0.25), and EQ-5D VAS (9.68 vs. 16.0). Most SF-36 section parameters also showed less improvement in the non-surgical treatment group than in the surgical treatment group throughout the 12-month follow-up. Conclusions In LSS patients without instability, non-surgical treatment resulted in less pain improvement and functional recovery through 1 year.

Among patients with cervical myelopathy who were diagnosed with neuropathic pain (NP) by the LANSS test, the study participants were randomly assigned to one of the two study groups. The participants in one study group received opioids only, while those in the other group received opioids and pregabalin. Thirty-nine patients were analyzed in the study (20 patients in the opioid-only group and 19 in the pregabalin add-on group). The LANSS, neck pain, and arm pain scores in the pregabalin add-on group improved significantly compared with those in the opioid-only group after the first 4 weeks (p = 0.005, 0.001 and 0.035, respectively), but there was no significant difference between the two groups during the next 4 weeks (p = 0.615, 0.377 and 0.716, respectively). There was no significant difference in the neck disability index and EuroQol-5Dimension scores after four weeks and eight weeks of follow-up. Adverse events were reported by four patients (20.0%) in the opioid-only group and five patients (26.3%) in the pregabalin add-on group (p = 0.716). However, over time, the occurrence of side effects and dropouts increased in the pregabalin add-on group. This exploratory pilot study suggests that pregabalin add-on treatment is more efficient than the use of opioids alone at the beginning of NP treatment in cervical myelopathy patients. However, prescribing pregabalin add-on treatment for more than four weeks should be done cautiously.

OBJECTIVEThis study investigated the incidence and risk factors of rod fracture (RF) after multiple-rod constructs (MRCs) for adult spinal deformity (ASD) surgery.METHODSA single-center, single-surgeon consecutive series of adult patients who underwent posterior thoracolumbar fusion at 4 or more levels using MRCs after osteotomy with at least 1 year of follow-up were retrospectively reviewed. Patient characteristics, radiological parameters, operative data, and clinical outcomes (on the Scoliosis Research Society-22r questionnaire) were analyzed at baseline and follow-up.RESULTSSeventy-six patients were enrolled in this study. RF occurred in 9 patients (11.8%), with all cases involving partial rod breakage. Seven patients (9.2%) underwent revision surgery. There were no significant differences in baseline demographic characteristics, radiological parameters, and surgical factors between the RF and non-RF groups. Multivariable analysis revealed that interbody fusion at the L5–S1 and L4–S1 levels could significantly reduce the occurrence of RF after MRCs for ASD (adjusted odds ratios 0.070 and 0.035, respectively). The RF group had significantly worse function score (mean 2.9 ± 0.8 vs 3.5 ± 0.7) and pain score (mean 2.8 ± 1.0 vs 3.5 ± 0.8) compared with the non-RF group at last visit.CONCLUSIONSRF occurred in 11.8% of patients with MRCs after ASD surgery. Most RFs occurred at the lumbosacral junction or adjacent level (77%). Interbody fusion at the lumbosacral junction (L5–S1 or L4–S1 level) could significantly prevent the occurrence of RF after MRCs for ASD.

Objective There is a lack of knowledge regarding whether decompression is necessary in treating patients with epidural spinal cord compression (ESCC) grade 2. The purpose of this study was to compare the outcomes of minimally invasive surgery (MIS) without decompression and conventional open surgery (palliative laminectomy) for patients with hepatocellular carcinoma (HCC) spinal metastasis of ESCC grade 2. Methods Patients with HCC spinal metastasis requiring surgery were retrospectively reviewed. Patients with ESCC grade 2, medically intractable mechanical back pain, a Nurick grade better than 3, 3-6 months of life expectancy, Tomita score ≥5, and Spinal Instability Neoplastic Score ≥7 were included. Patients with neurological deficits, other systemic illnesses and less than 1 month of life expectancy were excluded. Thirty patients were included in the study, including 17 in the open surgery group (until 2008) and 13 in the MIS group (since 2009). Results The MIS group had a significantly shorter operative time (94.2±48.2 minutes vs. 162.9±52.3 minutes, p=0.001), less blood loss (140.0±182.9 mL vs. 1534.4±1484.2 mL, p=0.002), and less post-operative intensive care unit transfer (one patient vs. eight patients, p=0.042) than the open surgery group. The visual analogue scale for back pain at 3 months post-operation was significantly improved in the MIS group than in the open surgery group (3.0±1.2 vs. 4.3±1.2, p=0.042). The MIS group had longer ambulation time (183±33 days vs. 166±36 days) and survival time (216±38 days vs. 204±43 days) than the open surgery group without significant difference (p=0.814 and 0.959, respectively). Conclusion MIS without decompression would be a good choice for patients with HCC spinal metastasis of ESCC grade 2, especially those with limited prognosis, mechanical instability and no neurologic deficit.

OBJECTIVE The object of this study was to compare, after a long-term follow-up, the incidence and features of adjacent segment disease (ASDis) following lumbar fusion surgery performed via an open technique using conventional interbody fusion plus transpedicular screw fixation or a minimally invasive surgery (MIS) using a tubular retractor together with percutaneous pedicle screw fixation. METHODS The authors conducted a retrospective chart review of patients with a follow-up period > 10 years who had undergone instrumented lumbar fusion at the L4–5 level between January 2004 and December 2010. The patients were divided into an open surgery group and MIS group based on the surgical method performed. Baseline characteristics and radiological findings, including factors related to ASDis, were compared between the two groups. Additionally, the incidence of ASDis and related details, including diagnosis, time to diagnosis, and treatment, were analyzed. RESULTS Among 119 patients who had undergone lumbar fusion at the L4–5 level in the study period, 32 were excluded according to the exclusion criteria. The remaining 87 patients were included as the final study cohort and were divided into an open group (n = 44) and MIS group (n = 43). The mean follow-up period was 10.50 (range 10.0–14.0) years in the open group and 10.16 (range 10.0–13.0) years in the MIS group. The overall facet joint violation rate was significantly higher in the open group than in the MIS group (54.5% vs 30.2%, p = 0.022). However, in terms of adjacent segment degeneration, there were no significant differences in corrected disc height, segmental angle, range of motion, or degree of listhesis of the adjacent segments between the two groups during follow-up. The overall incidence of ASDis was 33.3%, with incidences of 31.8% in the open group and 34.9% in the MIS group, showing no significant difference between the two groups (p = 0.822). Additionally, detailed diagnosis and treatment factors were not different between the two groups. CONCLUSIONS After a minimum 10-year follow-up, the incidence of ASDis did not differ significantly between patients who had undergone open fusion and those who had undergone MIS fusion at the L4–5 level.

Background Surgery for spinal metastasis is rapidly increasing in frequency with procedures ranging from laminectomy to spondylectomy combined with stabilization. This study investigated the effect of various surgical procedures for spinal metastasis of non-small cell lung cancer (NSCLC). Methods A single-center consecutive series of patients who underwent surgery for spinal metastasis of NSCLC were retrospectively reviewed. Patients' characteristics, radiographic parameters, operative data, clinical outcomes, and complications were analyzed. Surgical outcomes were assessed according to pain and performance status before and after surgery. Overall survival (OS) rate was estimated using the Kaplan-Meier method. Multivariate analysis was performed to detect factors independently associated with OS using a Cox proportional hazards model. Results Twenty-one patients were treated with laminectomy, 24 with corpectomy, 13 with spondylectomy (piecemeal or total en bloc fashion), and all procedures were combined with stabilization. Back pain and performance status improved significantly after surgical treatment among the three groups. Revision surgery due to tumor progression at the index level or spinal metastasis at another level were four patients (19.0%) in the laminectomy group, six patients (25.0%) in the corpectomy group, and one patient (7.7%) in the spondylectomy group. A Charlson comorbidity index and the number of spinal metastasis negatively affected OS (hazard ratio [HR], 19.613 and 2.244). Postoperative chemotherapy, time to metastasis, spondylectomy, and corpectomy had favorable associations with OS (HR, 0.455, 0.487, 0.619, and 0.715, respectively). Conclusion Postoperative chemotherapy was the most critical factor in OS of patients with metastatic NSCLC to the spine. An extensive surgical procedure (corpectomy/spondylectomy) with stabilization also could be beneficial for limited patients with spinal metastasis of NSCLC., Graphical Abstract

Spinal cord tumors are uncommon neoplasms that, without treatment, can cause significant neurologic morbidity and mortality. Spinal cord tumors can be divided into intraependymal, intrapial extraependymal, pial, intraarchnoidal extrapial, extraarachnoidal intradural, dural, and transcompartmental based on anatomical compartment. In this chapter, we reviewed spinal cord tumors in terms of epidemiological, clinical, and radiographic characteristics. Surgical and adjuvant treatment options are also reviewed.

To compare lateral (direct [DLIF] or oblique [OLIF]) and posterior (posterior [PLIF] or transforaminal [TLIF]) lumbar interbody fusion results in patients with the same indication of discogenic low back pain.We enrolled 46 patients who underwent single-level DLIF/OLIF or PLIF/TLIF with at least 1 year of follow-up. Patients were divided into two groups: a lateral group (n=24) who underwent DLIF/OLIF and a posterior group (n=22) who underwent PLIF/TLIF. Clinical, surgical, and radiological outcomes were retrospectively evaluated.Baseline factors, including demographic data, preoperative symptoms, and preoperative radiological findings, were not significantly different between the two groups. In addition, the clinical and radiological outcomes at 1-year post-surgery did not differ between the two groups. However, the DLIF/OLIF procedure conferred significant advantages as follows: favorable postoperative low back pain and patient satisfaction at 1-week and 1-month post-surgery; shorter operation time (mean 173.33 ± 11.54 versus 208.64 ± 17.48 min, p0.001); less blood loss during surgery (mean 127.50 ± 41.36 versus 372.73 ± 123.21 mL, p0.001); and greater restoration of calibrated disc height at 1-year post-surgery (mean 5.80 ± 1.44 versus 0.50 ± 1.22, p=0.008). There was no statistically significant difference in the incidence of complications between the two groups. However, complications tended to be more frequent in the lateral group; 7 (29.2%) patients in the lateral group and 3 patients (13.6%) in the posterior group.Our findings suggest that the lateral group achieved better perioperative outcomes and disc height restoration than the posterior group, although there was no significant difference in the 1-year clinical outcomes.

Objective Expansion in the spinal canal area (SCA) after laminoplasty is one of the critical factors to relieve the preoperative symptoms. No previous study has compared the increases in SCA achieved by open-door laminoplasty (ODL) and double door laminoplasty (DDL) according to the preoperative lamina angle (LA). This study was designed to clarify the relationship between the laminoplasty opening angle (OA)/laminoplasty opening size (OS) and increases in the SCA following ODL and DDL according to the preoperative LA using a simulation model. Methods The simulation model was constructed and validated by comparing the clinical data of 64 patients who had undergone C3–C6 laminoplasty (43 patients with ODL and 21 patients with DDL). SCA expansion was predicted with a verified simulation model at various preoperative LAs (from 28° to 32°) with different OAs (40° to 44°) and OSs (10 mm to 14 mm) recruited from patient data. Results The constructed simulation model was validated by comparing clinical data and revealed a very high degree of correlation (r=0.935, p0.05). The difference was significant when the preoperative LA was narrower or much wider. Conclusion Based on clinical data, a simulation model was constructed and verified that could predict increases in the SCA following ODL and DDL. When applying this model, prediction in SCA increase using the OS parameter was more practical and compatible with clinical data. Both laminoplasties achieved enough SCA, and there was no significant difference between them in the usual range.

Background S2-alar-iliac (S2AI) screws improve stability across the lumbosacral junction in spinopelvic fixation procedures by crossing the cortical surfaces of the sacroiliac joint (SIJ), thereby increasing the biomechanical strength of the instrumentation. Objective To investigate the durability and failure types of S2AI screws after spinopelvic reconstruction surgery. Methods A single-center, single-surgeon consecutive series of patients who underwent spinopelvic fixation using bilateral S2AI screws with a ≥1-yr follow-up and at least 1 postoperative computed tomographic scan were retrospectively reviewed. Patient characteristics, radiographic parameters, operative data, clinical outcomes, and complications were analyzed. Results In total, 312 S2AI screws in 156 patients were evaluated (mean follow-up, 26.1 mo; range 12-71 mo). There were no significant differences in screw diameter, length, or insertion angle between right-side and left-side screws. Visual analogue scale scores for back pain, ambulatory status, and Oswestry Disability Index scores significantly improved. A total of 10 patients (3.2%) experienced SIJ pain after S2AI screw installation. SIJ pain improved in 8 of them following SIJ block. In total, 7 screws (2.2%) showed partial periscrew lucency. Set screw dislodgement occurred in 7 screws (2.2%). Screw fracture occurred in 6 screws (1.9%): 5 neck fractures and 1 shaft fracture. A total of 5 patients (1.6%) underwent revision surgery for S2AI screw failure. Distal device (L4-pelvis region) breakage occurred in 5 patients. Conclusion The radiographic and clinical outcomes of S2AI screw fixation were acceptable. However, S2AI screw fixation has several drawbacks, including screw fracture and dislodgement of the set screw. SIJ irritation symptoms after S2AI screw fixation occurred with considerable frequency.

Study design Retrospective cohort study of a nationwide sample database. Objective The objective of the present study was to compare the long-term incidence of reoperation for lumbar spinal stenosis (LSS) after anterior fusion, posterior fusion, and decompression. Summary of background data Surgical treatment for LSS can be largely divided into 2 categories: decompression only and decompression with fusion. A previous nationwide study reported that fusion surgery was performed in 10% of patients with LSS, and the 10-year reoperation rate was approximately 17%. However, with the development of surgical techniques and changes in surgical trends, these results should be reassessed. Methods The National Health Insurance Service-National Sample Cohort of the Republic of Korea was utilized to establish a cohort of adult patients (N = 1400) who first underwent surgery for LSS during 2005 to 2007. Patients were followed for 8 to 10 years. Considering death before reoperation as a competing event, reoperation hazards were compared among surgical techniques using a Fine and Gray regression model after adjustment for sex, age, diabetes, osteoporosis, Charlson comorbidity index, severity of disability, type of medical coverage, and type of hospital. Results The overall cumulative incidence of reoperation was 6.2% at 2 years, 10.8% at 5 years, and 18.4% at 10 years. The cumulative incidence of reoperation was 20.6%, 12.6%, and 18.6% after anterior fusion, posterior fusion, and decompression, respectively, at 10 years postoperatively (P = 0.44). The first surgical technique did not affect the reoperation type (P = 0.27). Decompression was selected as the surgical technique for reoperation in 83.5% of patients after decompression, in 72.7% of patients after anterior fusion, and in 64.3% of patients after posterior fusion. Conclusion The initial surgical technique did not affect reoperation during the 10-year follow-up period. Decompression was the most commonly used technique for reoperation. Level of evidence 4.

The diagnosis of discogenic low back pain (LBP) from disc degeneration of the lumbar spine is often evaluated with discography. Noninvasive, simple screening methods other than invasive discography are useful, as evidence supporting clinical findings and magnetic resonance imaging (MRI) have come to the forefront.To investigate disc height (DH) discrepancy between supine and standing positions on simple radiography to clarify its clinical screening value in individuals with discogenic LBP.Retrospective matched cohort design.Ninety-two patients with early to middle stage disc degeneration (Pfirrmann grade II, III, or IV).Each subject underwent simple radiographs and MRI. Baseline characteristics, including demographic data and MRI findings, and radiological findings, including DH discrepancy, segmental angle, and sagittal balance, were analyzed. DH discrepancy ratio was calculated as (1 - [calibrated DH on standing radiography/calibrated DH on supine radiography]) × 100%.We matched LBP group of 46 patients with intractable discogenic pain (≥7 of visual analog scale scores) confirmed by discography with control group of 46 patients with similar stage disc degeneration with mild LBP (≤4 of visual analog scale scores). Binary regression analysis, receiver operating characteristic curve analysis, and cut-off value for diagnosis were used to evaluate and clarify diagnostic value of various factors.There was no significant difference between the two groups in terms of baseline characteristics, including age, sex, body mass index, pathological level, and magnetic resonance findings such as disc degeneration, high intensity zone, and para-spinal muscle volume. Among the various radiological findings, the calibrated mean DH in the standing position (20.87±5.65 [LBP group] vs. 26.95±3.02 [control group], p.001) and the DH discrepancy ratio (14.55±6.13% [LBP group] vs. 1.47±0.75% [control group], p=.007) were significantly different between the two groups. The cut-off value for DH discrepancy ratio to screen discogenic LBP was ≥6.04%. Additionally, as a compensation for pain, sagittal vertical axis (3.43±2.03 cm [LBP group] vs. -0.54±3.05 cm [control group], p=.002) and pelvic incidence (54.74±6.76° [LBP group] vs. 43.98±8.67° [control group]; p=.006) were different between the two groups.The results suggest that DH discrepancy between the supine and standing positions could be a screening metric for discogenic LBP in early to middle stage disc degeneration of the lumbar spine.

A retrospective cohort study.The aim of this study was to identify the risk factors for acute progression of myelopathic symptoms (PMS) associated with ossification of the posterior longitudinal ligament (OPLL) after minor trauma and to compare the prognosis between an acute PMS group and a chronic PMS group.Although the prevalence of OPLL among patients with cervical myelopathy is high, few studies have been published regarding the risk factors for acute PMS associated with OPLL after minor trauma.Patients with OPLL who had histories of minor trauma and had undergone surgery were divided according to clinical course into an acute (within 48 hours, n = 38) and a chronic PMS group (n = 32). The type of trauma and the clinical and radiologic characteristics were compared. The clinical outcomes were also compared at admission and at 1 and 2 years postoperatively.The types of trauma were significantly different between the two groups (P 0.05). Univariate analysis revealed that older age, a narrower space available for the cord, and a higher rate of stenosis in the spinal canal were associated with acute PMS after minor trauma (P = 0.014, 0.020, and 0.006, respectively). However, the rate of stenosis in the spinal canal was the only risk factor that was identified in a multivariate analysis (P = 0.023; odds ratio, 0.872; 95% confidence interval, 0.774-0.982). The Japanese Orthopedic Association scores at the initial visit and at postoperative years 1 and 2 were significantly lower in the acute PMS group than in the chronic PMS group (P 0.001, P 0.001, and P 0.001, respectively).One risk factor for acute PMS in patients with OPLL after minor trauma is a higher rate of stenosis of the spinal canal. Patients with acute PMS exhibited unfavorable neurologic outcomes. Preventive surgical treatment may be recommended for patients with significant OPLL with mild cervical myelopathy.3.

Transforaminal endoscopic lumbar discectomy (TELD) is useful for soft lumbar disc herniation (LDH). Although the transforaminal approach can reach the foraminal disc zone, the risk of exiting nerve root irritation along the path is considerable. Few studies have assessed the difficulties of TELD for foraminal LDH. The objective of this study is to compare the clinical results of TELD between foraminal or far-lateral LDH and paramedian LDH. Between June 2016 and July 2017, 135 consecutive patients with single-level LDH were treated with TELD for 2 years. Among them, 25 patients had foraminal or far-lateral LDH (foraminal group), and the remaining 110 patients had central or subarticular LDH (paramedian group). Perioperative data and clinical outcomes were evaluated using the visual analog pain scale, Oswestry Disability Index, and modified Macnab criteria. The foraminal group showed a higher rate of significant access pain (24.00% vs 8.19%, P

A retrospective cohort study of a nationwide sample database.The objective of the present study was to compare the long-term incidence of reoperation for lumbar herniated intervertebral disc disease (HIVD) after major surgical techniques (open discectomy, OD; laminectomy; percutaneous endoscopic lumbar discectomy, PELD; fusion).HIVD is a major spinal affliction; if the disease is intractable, surgery is recommended. Considering both the aging of patients and the chronicity of lumbar degenerative disease, the effect of surgical treatment for the lumbar spine should be durable for as long as possible.The National Health Insurance Service-National Sample Cohort (NHIS-NSC) of Republic of Korea was utilized to establish a cohort of adult patients (N = 1856) who underwent first surgery for lumbar HIVD during 2005 to 2007. Patients were followed for 8 to 10 years. Considering death before reoperation as a competing event, reoperation hazards were compared among surgical techniques using the Fine and Gray regression model after adjustment for age, gender, Charlson comorbidity score, osteoporosis, diabetes, the severity of disability, insurance type, and hospital type.The overall cumulative incidences of reoperation were 4% at 1 year, 6% at 2 years, 8% at 3 years, 11% at 5 years, and 16% at 10 years. The cumulative incidences of reoperation were 16%, 14%, 16%, and 10% after OD, laminectomy, PELD, and fusion, respectively, at 10 years postoperation, with no difference among the surgical techniques. However, the distribution of reoperation types was significantly different according to the first surgical technique (P 0.01). OD was selected as the reoperation surgical technique in 80% of patients after OD and in 81% of patients after PELD.The probability of reoperation did not differ among OD, laminectomy, PELD, and fusion during the 10-year follow-up period. However, OD was the most commonly used technique in reoperation.4.

BACKGROUND In cervical open-door laminoplasty for cervical myelopathy, a high-speed rotatory drill and rongeurs are used to make unicortical troughs and bicortical openings in the laminae. The lamina is reflected at the trough to enlarge the spinal canal, followed by bone healing on the hinge side to stabilize laminoplasty. The ultrasonic bone scalpel (UBS) has been used due to theoretical advantages including a better hinge union rate, less soft tissue trauma, less neurological injury, and shorter operative time. OBJECTIVE To assess the superiority of UBS for hinge union compared to the drill through randomized controlled trial. METHODS In 190 randomly allocated cervical myelopathy patients, the trough and opening at the lamina were made using either the drill (n = 95) or UBS (n = 95) during 2015 to 2018. The primary outcome was the hinge union rate on 6-mo postoperative computed tomography. Secondary outcomes included the hinge union rate at 12 mo, the operative time, intraoperative/postoperative bleeding, neurological injury, complications, and clinical outcomes over a 24-mo follow-up. RESULTS Hinge union in all laminae was achieved in 60.0% (drill) and 43.9% (UBS) of patients at 6 mo (intention-to-treat analysis; P = .02; odds ratio, 2.1) and in 91.9% (drill) and 86.5% (UBS) at 12 mo. Dural injury only occurred in the drill group (2.1%), and the UBS group showed significantly less intraoperative bleeding (P

Objective Subsidence of the interbody graft into the vertebral bodies is one of the major complications of direct lateral interbody fusion (DLIF), resulting in pseudoarthrosis and severe pain. Low bone mineral density (BMD) has been known to increase the risk of subsidence. This study aims to determine whether or not the osteopenia should influence the surgical results in DLIF surgery. Methods We retrospectively reviewed the data collected prospectively on all patients who underwent single-level DLIF at our institution. A total of 84 patients were included in this study, comprised of 41 in the osteopenia group and 43 in the normal BMD group. The clinical and radiologic characteristics were compared at preoperative and postoperative 1 and 2 years. Results At postoperative two years, there was a statistically significant difference in disc height and intervertebral foramen height at index level between the two groups (p = 0.039, 0.044, respectively), but there was no significant difference in total lumbar lordosis (p = 0.179). At 24-month postoperative, 92.7% of the osteopenia group and 95.3% of the normal BMD group were solidly fused (p = 0.672). All postoperative clinical scores (VAS back pain, VAS leg pain, and ODI) improved similarly in both groups without significant difference. The overall incidence of cage subsidence with >3 mm was 17.1% in the osteopenia group and 9.3% in the normal BMD group (p = 0.345). Conclusions Patients with osteopenia who undergo single-level DLIF combined with posterior fixation exhibited comparable clinical and radiological outcomes as patients with normal BMD.

To evaluate the learning curve of percutaneous endoscopic transforaminal lumbar discectomy (PETLD) from the novice stage to the proficient stage, we performed retrospective study for patients with lumbar disc herniation who underwent PETLD performed by a single surgeon and evaluated the surgeon's learning curve and the effect of surgical proficiency on outcomes. A total of 48 patients who underwent PETLD at the lower lumbar level (L3–S1) with a minimum 1-year follow-up were enrolled. The learning curve of the surgeon was assessed using cumulative study of operation time and linear regression analyses to reveal the correlation between operation time and case series number. Because the cutoff of familiarity was 25 cases according to the cumulative study of operation time, the patients were allocated into two groups: early group (n = 25) and late group (n = 23). The clinical, surgical, and radiological outcomes were retrospectively evaluated and compared between the two groups. According to linear regression analyses, the operation time was obtained using the following formula: operation time (minutes) = 69.925–(0.503 × [case number]) (P

Residual disc fragments are observed on immediate postoperative magnetic resonance imaging (MRI) in 2.8-15% of patients after percutaneous endoscopic lumbar discectomy (PELD). Considering the known postoperative longitudinal outcomes in patients with residual disc tissue, a 'watchful waiting' strategy may be preferable to immediate re-operation in patients with asymptomatic residual disc material.The aim of the present study was to compare the longitudinal clinical outcomes between PELD patients in whom the complete removal of disc fragments was achieved (complete group) and those in whom residual disc fragments were observed on postoperative MRI (residual group).Retrospective nested case-control study.A total of 225 patients were included (complete group, n=187 and residual group, n=38). Clinical assessments were performed using the visual analog pain score for the leg (VAS-L, x/10) and back (VAS-B, x/10) and the Korean version of the Oswestry Disability Index (K-ODI, x/45). A linear mixed-effects model was used to analyze changes during the first 24 postoperative months.One month after surgery, significant improvements in the VAS-L, VAS-B and K-ODI values were observed and were maintained during the first 24 postoperative months. No differences in these changes were noted between the groups. Early re-operation (during the first 3 postoperative months) was performed in 3 patients in the residual group (7.9%) and in 4 patients in the complete group (2.1%) (P = 0.10).First, the study design was retrospective. Moreover, the number of patients was relatively small and therefore insufficient to achieve robust statistical power. Second, we did not explore the radiological outcomes in patients with asymptomatic residual disc material because follow-up MRI was only obtained to document symptom recurrence.When residual disc tissue is observed in asymptomatic patients, a 'watchful waiting' strategy may be preferable to immediate re-operation. However, an increased early re-operation rate is expected for patients with residual disc tissue.Discectomy, endoscopes, longitudinal studies, patient-reported outcome, percutaneous, reoperation, spine, residual disc.

Among the spinal disorders, the treatment approach for spinal deformities has been discussed least among department of neurosurgery. But nowadays, more and more neurosurgeons are interested in spinal deformities as well as complex spinal disorders and are doing not a few surgeries for these kinds of disease. Nevertheless, it is mandatory to understand the course of spinal deformity, principles of treatment, and surgical outcomes and complications. Understanding of the biology, biomechanics and metallurgy of the spine and instrumentation are also required for successful spinal deformity surgery. We need senior mentors and good surgical and neurophysiologic monitoring team. Knowledge of spinal deformity may be augmented with spine fellowships and surgical experience. Step by step training such as basic knowledge, orthopedic as well as neurosurgical disciplines and surgical skills would be mandatory. Neurosurgeons can have several advantages for spinal deformity surgeries. By high-level technical ability of the spinal cord handling to preserve neurological function and familiarity with microscopic surgery, better synergistic effect could be expected. A fundamental understanding of pediatric spinal deformity and growing spine should be needed for spinal deformity surgery.

Objective Examining spine surgery patterns over time is crucial to provide insights into variations and changes in clinical decision making. Changes in the number of surgeries, surgical methods, reoperation rates, and cost-effectiveness were analyzed for all patients who underwent surgery for lumbar spinal stenosis without spondylolisthesis in 2003 (2003 cohort) and 2008 (2008 cohort). Methods The national health insurance database was used to create the 2003 cohort (n = 10,990) and 2008 cohort (n = 27,942). The surgical methods were classified into decompression and fusion surgery. The cumulative reoperation probability between those surgeries was calculated using the Kaplan-Meier method in the 2003 cohort and 2008 cohort. Comparison of the incremental cost-effectiveness ratios showed the additional direct cost of a 1% change in the reoperation probability. Results The surgical volume increased 2.54-fold in the 2008 cohort. The age-adjusted number of surgeries per 1 million people increased 2.6-fold (from 154 in the 2003 cohort to 399 in the 2008 cohort) in aged patients and 1.9-fold (from 154 in the 2003 cohort to 291 in the 2008 cohort) in patients 20–59 years old in the 2008 cohort. The proportion of fusion surgeries increased from 20.3% in the 2003 cohort to 37.0% in the 2008 cohort. In total, the 5-year reoperation probabilities increased from 8.1% in the 2003 cohort to 11.2% in the 2008 cohort. Fusion decreased the reoperation probability by 1% at the cost of 1,711 U.S. dollars. Conclusions The increased numbers of spinal surgeries, fusion surgeries, and surgeries in older patients in a recent cohort were noteworthy. However, the increased surgical volume and fusion surgeries did not reduce the reoperation rate.

Herniated intervertebral disc disease (HIVD) is a common cause of lower back and leg pain. Percutaneous endoscopic lumbar discectomy (PELD) is indicated when non-surgical treatments such as medication and interventions are intractable. Ruptured discs and loose fragments inside discs are removed during PELD. Nerve root decompression is usually assessed by visualizing the free movement of the traversing nerve root or epidural fat, the free passage of a probe into the epidural space, the depression of the annulus, and the removal of the expected ruptured discs and loose fragments based on preoperative magnetic resonance images (MRI). However, these criteria are subjective, and the quantity of the disc removal necessary for successful outcomes after PELD has not been investigated.The present study investigates the amount of discectomy of PELD and its clinical and radiological outcomes.A retrospective case study (IRB Number H-1611-015-803).University Medical Center, Seoul, Korea.PELD was performed in 109 consecutive patients (M:F = 53:56; mean age, 37.4 years) using the transforaminal or interlaminar route. Ruptured disc fragments were first removed in all patients, and the graspable loose fragments under the disc were removed. After surgery, all removed disc fragments were placed into disposable syringes and manually compressed to measure their volume. The volume of herniated disc outside the disc boundary was calculated in MRI. The measured and calculated disc volumes were retrospectively compared. Clinical success was defined as an improvement in both the Oswestry Disability Index (ODI) and leg pain, as well as no recurrent symptoms. Radiological success was defined as the disappearance of herniated disc material outside the disc boundary based on postoperative MRI taken within one day after surgery. The follow-up period was 7.2 ± 5.2 months.Successful clinical outcomes were obtained in 96/109 (88.1%) patients in a median time of 3 months. Re-operation was performed in 3 patients due to recurrent discs in 2 patients and a residual disc in one patient. Predictors of clinical success were not identified, and the quantity of the removed disc was not associated with the clinical outcome. Radiological success was achieved in 93/109 (85.3%) patients. Of 13 patients with radiological failure, 2 patients showed clinical failure. A logistic regression analysis showed that the relative volume of the removed disc (%) compared with the volume of preoperative herniated disc based on the MRI was the only significant predictor (P0.001; OR = 0.96). When 100% of the calculated disc amount was removed during the operation, the probability of residual disc was 30%. When 131% of the calculated disc amount was removed, the probability of residual disc was 10%.This study employed a retrospective design, and its inherent selection bias and limited statistical power should be considered.The amount of disc removal during PELD was not a significant predictor of clinical success after the primary ruptured fragments were removed. The relative volume of the removed disc based on the preoperative MRI might predict the postoperative MRI.Disc, lumbar vertebra, discectomy, surgery, endoscopy, volume.

A 42-year-old man presented with a one-month history of upper back pain and a two-week history of progressive spastic paraparesis. Thoracic spinal MRI showed an epidural mass with spinal cord compression at T6-8 but no bony involvement. The patient underwent T6-8 laminectomy for decompression. Lumbosacral MRI and CT scans revealed bony abnormalities on the sacrum and left posterior iliac bone. Immunohistochemical studies confirmed the diagnosis of multiple myeloma (MM). Thus, this patient suffered from extraosseous MM without adjacent bony involvement or distant skeletal involvement.

There are a number of complications associated with ventriculoperitoneal shunt (VPS) surgery. The authors present a rare case of iatrogenic common carotid artery injury during VPS surgery.