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Background Condoliase-induced chemonucleolysis is a less-invasive alternative treatment for lumbar disc herniation (LDH); however, its long-term clinical outcome is still unclear. This study aimed to investigate 1-year clinical outcomes and assess radiographs after chemonucleolysis with condoliase. Methods We enrolled patients with LDH who received condoliase injection with a follow-up period of >1 year. Sixty patients (37 men, 23 women; mean age, 44.5 ± 18.9 years; mean follow-up period, 22.0 ± 6.0 months) were analyzed. Changes in disc height and degeneration were evaluated using magnetic resonance imaging. Visual analog scale (VAS) scores for leg and back pain and the Oswestry disability index (ODI) were obtained. All data were assessed at baseline, 1-month, 3-month, and 1-year follow-up. Results Surgical treatment was subsequently required in 8 patients (12.5%) after condoliase therapy. Their ODI and VAS scores for leg pain and back pain significantly improved at 1 year, as in those who received condoliase therapy only. On MRI, progression of Pfirrmann grade was observed in 23 patients (44.2%) at 3 months; however, 8 patients recovered to baseline at 1 year. The mean disc height decreased at 3 months; however, it recovered at 1 year. Disc height recovery (disc recovery rate >50%) was observed in 30.8% of the patients. Patients with disc height recovery were significantly younger than those without. Patients with longer symptom duration (≥1 year) showed significantly lower rates of effectiveness compared with those with shorter symptom durations ( Conclusions Chemonucleolysis with condoliase is a safe and minimally invasive treatment. Disc degeneration induced by chemonucleolysis could be recovered, particularly in younger patients. Prolonged symptom duration had adverse effects on outcome; thus, therapeutic intervention at the optimal time is needed.

Background Surgical treatment for adolescent idiopathic scoliosis (AIS) has changed significantly with the advent of new medical devices and surgical procedures. Today, pre- and postoperative management differs widely between institutions. The purpose of this study is to establish consensus regarding the surgical management of AIS in Japan through the use of a questionnaire survey of experienced spine deformity surgeons. Methods From February to March 2020, experienced spine deformity surgeons who perform more than 25 cases of AIS surgery annually were asked to respond to a questionnaire request regarding AIS surgical management formulated by the International Affairs Committee of the Japanese Scoliosis Society. For each of the questions, consensus was achieved upon a 70% agreement among respondents. Results Responses were received from 25 of the 32 (78%) experienced spine deformity surgeons. The average age of the responding surgeons was 52 years with an average practice experience of 28 year. Consensus was achieved on 74 (76%) of the 97 aspects of care presented in the questionnaire and is broken down as follows: 12 of 17 items for preoperative management, all 5 items for perioperative management, 11 of 14 items for surgical technique, 9 of 15 items for implant selection, 6 of 8 items for bone grafting, 7 of 10 items for blood conservation, 5 of 7 items for postoperative management, all 17 items for postoperative evaluation, and 2 of 4 items for aftercare. Conclusions Expert consensus was achieved on 74 aspects of the surgical management of AIS in Japan. In implant selection and aftercare, consensus was obtained in less than 70% of the aspects, revealing differences in AIS management between institutions. These findings on AIS surgery in Japan, informed by expert opinion, will conceivably help spine deformity surgeons determine appropriate surgical management of AIS.

Study DesignCombination of retrospective and prospective study.PurposeWe aimed to compare the clinical outcomes between local fixation surgery and spinopelvic fixation surgery for the treatment of kyphosis secondary to osteoporotic vertebral fractures with spinopelvic malalignment.Overview of LiteratureThe clinical characteristics of patients with rigid kyphosis due to osteoporotic vertebral fracture differ from that of middle-aged patients with vertebral fractures in terms of bone fragility and presence of spinopelvic malalignment. Little is known about the surgical strategies for these deformities, most especially the extent of fusion of vertebra involved.MethodsWe analyzed 24 patients with vertebral osteotomy at the level of the fracture and spinal fixation without pelvic fixation (local group), and 22 patients with vertebral osteotomy and pelvic fixation (pelvic group). Radiographic parameters, the incidence of proximal junctional kyphosis (PJK), distal junctional kyphosis (DJK), rod fractures, and the Oswestry Disability Index (ODI) were compared between the two groups over a 2-year follow-up period.ResultsIn the pelvic group, postoperative spinopelvic parameters significantly improved, with the improvements maintained. No remarkable changes in spinopelvic parameters were seen in the local group. The mean ODI scores 2 years after surgery were 45.3 and 33.0 in the local and pelvic group, respectively (p-value

OBJECTIVE Extensive corrective fusion surgery was performed on elderly patients with adult spinal deformity (ASD) to improve abnormal posture. Varying improvements in postoperative walking function were expected owing to differences in muscular strength and bone quality between patients in their 40s and those over 75 years of age. The purpose of this study was to compare preoperative and postoperative gait posture and physical functionality in elderly patients with ASD who underwent extensive corrective fusion to the thoracic spine. METHODS A prospectively maintained surgical database was reviewed for patients with ASD who underwent corrective fusion surgery (thoracic spine to pelvis) between 2011 and 2016. The cohort was divided into three age groups: nonelderly (40–64 years), young-old (65–74 years), and old-old (> 75 years). Patients underwent a 4-m walk test preoperatively and 2 years postoperatively to measure gait-trunk tilt angle and walking speed (meters per minute). RESULTS Among 291 patients with ASD who underwent corrective fusion surgery, 56 patients (14 men and 42 women; mean age 68.8 years) were included. Mean preoperative gait-trunk tilt angle (12.9° vs 5.2°, p < 0.01) and walking speed (41.2 m/min vs 45.7 m/min, p < 0.01) significantly improved postoperatively. Intergroup analysis revealed that the mean preoperative gait-trunk tilt angles in the nonelderly (n = 13), young-old (n = 28), and old-old (n = 15) groups were 11.9°, 10.0°, and 19.3°, respectively; postoperatively, these improved to 4.5°, 4.5°, and 7.2°, respectively. Mean preoperative walking speeds of 47.9, 40.0, and 37.7 m/min improved to 52.4, 44.8, and 41.5 m/min postoperatively in the nonelderly, young-old, and old-old groups, respectively. There were no statistically significant differences in degree of improvement in gait-trunk tilt angle and walking speed among groups. CONCLUSIONS Extensive corrective fusion surgery improved the postoperative walking posture of patients with ASD. Statistical analysis of gait measurements demonstrated intergroup equivalence, indicating comparable improvement in physical functionality in elderly and middle-aged patients after corrective fusion surgery.

Purpose: To determine the effect of planned two-stage surgery using lateral lumbar interbody fusion (LLIF) on the perioperative complication rate following corrective fusion surgery in patients with kyphoscoliosis.Methods: Consecutive patients with degenerative scoliosis who underwent corrective fusion were divided into a control group that underwent single-stage posterior-only surgery and a group that underwent planned two-staged surgery with LLIF and posterior corrective fusion. We collected the patient background and surgical data and assessed the perioperative complication rates. We also investigated spinopelvic parameters and patient-reported outcome measurements (PROMs).Results: One hundred and thirty-eight patients of mean age 69.8 (range, 50–84) years who met the study inclusion criteria were included. The two-stage group (n=75) underwent a staged anterior-posterior surgical procedure and the control group (n=63) underwent single-stage surgery. There was no significant between-group difference in the incidence of perioperative complications, except for deep wound infection (reoperation is necessary for surgical site infection). Revision surgery within 3 months of the initial surgery was more common in the control group (n=8, 12.7%) than in the two-stage group (n=3, 4.0%). Spinopelvic parameters and PROMs were significantly better in the two-stage group at 2 years postoperatively.Conclusion: The complication rate for planned two-stage surgery was similar to that of previous posterior-only single-stage surgery. However, early reoperation was less common, and the degree of spinal correction and clinical results were significantly better after two-stage surgery.

Study Design: A finite element analysis study. Objective: Of proximal junctional failure, upper instrumented vertebra (UIV) fracture can causes severe spinal cord injury. Previously, we reported that higher occupancy rate of pedicle screw (ORPS) at UIV prevented UIV fracture in adult spinal deformity surgery; we had not yet tested this finding using a biomechanical study. The purpose of present study was to measure the differences in loads on the UIV according to the length of PS and ORPS. Methods: We designed an FE model of a lumbar spine (L1-S1) using FE software. The PS was set from L2 to S1 and connected the rod. The FE model simulated flexion (8 Nm) to investigate the loads at UIV (L2) according to the length of the PS. There were 5 screw lengths examined: 40 (ORPS 36.4%), 45 (48.5%), 50 (66.7%), 55 (81.8%), and 60 mm (93.9%). Results: Stress with bending motion was likely to occur at the upper front edge of the vertebral body, the pedicles, and the screw insertion point. The maximum equivalent stress according to screw lengths of 40, 45, 50, 55, and 60 mm were 45.6, 37.2, 21.6, 13.3, and 14.8 MPa, respectively. The longer screw, the less stress was applied to UIV. No remarkable change was observed between the screw lengths of 55 and 60 mm. Conclusions: Increasing ORPS to 81.8% or more reduced the load on the UIV. To prevent UIV fracture, the PS length in the UIV should be more than ORPS 81.8%.

Solitary fibrous tumors are rare mesenchymal neoplasms with highly recurrence rates after intratumor resection. We report 2 cases of solitary fibrous tumors treated with combination therapy with embolization and en bloc laminectomy using thread saw. To the best of our knowledge, this is the first such report. In the 2 cases, the hypervascular tumors were located in the spinal process and infiltrating the multifidus. Preoperative embolization was useful for decreasing intraoperative bleeding, and using thread saw was an ideal technique for deciding the cut surface height of the pedicle to achieve gross total resection.

Malnutrition is reported as one of the risk factors for surgical site infection (SSI). The prognostic nutritional index (PNI) is a simple method for nutritional evaluation. However, little is known about the relationship between SSI and the PNI in patients after spine surgery. We aimed to determine independent predictors of SSI after spine surgery. We analyzed 1115 patients who underwent spine surgery (369 males, 746 females, mean age 56 years, follow-up period: at least 1 year). Patients were divided into SSI and non-SSI groups. Preoperative risk factors, including PNI (10 × serum albumin [g/dL] + 0.005 × total lymphocyte count [/μL]), were assessed. Postoperatively, 43 patients (3.9%) experienced SSI. Univariate analysis showed that preoperative PNI (48.5 vs 51.7; p

Purpose: There is controversy regarding age-related deterioration of spinal sagittal alignment in cross-sectional study. Although we reported that deterioration in spinal alignment originated at the cervical spine in males and the pelvis in females, others studies have indicated that the lumbar spine is initially implicated in both sexes. The purpose of this study was to clarify these differences in a longitudinal cohort study.Methods: Our analysis was based on 237 individuals aged 60-89 years who participated in our health screening study in 2014 and 2018. They were classified into 6 groups by birth-year and sex: 60-69 years (26 males, 49 females); 70-79 years (35 males, 88 females); and 80-89 years (19 males, 20 females). The following parameters were measured from standing radiographs: pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), thoracic kyphosis (TK), T1 slope (TS), cervical lordosis (CL), C7 sagittal vertical axis (C7 SVA), and C2-7 SVA.Results: In males, the first significant change was an increase in the PT angle (19°, in 2014, to 21°, in 2018) in the 80-89 years age group (P

OBJECTIVEMany complications are likely to occur in patients with malnutrition. The prognostic nutritional index (PNI) is often used when evaluating a patient’s nutritional condition. However, no studies have investigated the association between nutritional status and postoperative medical complications or prognosis by using the PNI in the field of spinal surgery. The purpose of this retrospective study was to investigate postoperative medical complications and prognoses of patients who had undergone adult spinal deformity (ASD) surgery, according to their preoperative nutritional status.METHODSAll patients aged ≥ 40 years who had undergone scheduled ASD surgery in the authors’ hospital between March 2010 and June 2017 were eligible for study inclusion and were divided into groups according to their PNI (< 50, group L; ≥ 50, group H). Medical complications diagnosed within 30 days postoperatively were evaluated; however, surgical site infection and death were evaluated until 1 and 5 years after surgery, respectively.RESULTSAmong the 285 eligible patients, groups L and H consisted of 118 and 167 patients, whose mean ages were 68.6 and 68.3 years, respectively. There was a significant difference in body mass index (22 vs 24 mg/kg2, respectively, p = 0.000), PNI (46 vs 55, p = 0.000), comorbidity of osteoporosis (50% vs 32%, p = 0.005) and autoimmune disease (13% vs 5%, p = 0.036), medical history of malignant disorder (17% vs 6%, p = 0.007), and medical complications (49% vs 23%, p = 0.000) between groups L and H. Multiple logistic regression analysis suggested that significant risk factors for postoperative medical complications were male sex (p = 0.000, OR 3.5, 95% CI 1.78–6.96), PNI < 50 (p = 0.000, OR 2.9, 95% CI 1.69–4.93), and days to ambulation (p = 0.003, OR 1.1, 95% CI 1.02–1.09).CONCLUSIONSMedical complication rates are significantly higher in patients with PNI < 50, those with delayed ambulation, and male patients. In malnourished patients scheduled for ASD surgery, improvement of preoperative nutritional status and postoperative early ambulation are important to avoid medical complications.

Several studies indicated the influence of age and sex on spinal alignment using spino-pelvic radiographic parameters. However, information regarding the geometrical assessment of the sagittal spinal plane in the elderly population remains limited. This study aimed to determine the apices of lumbar lordosis and thoracic kyphosis, and spinal inflection point in elderly individuals and clarify the effect of age, sex, and pelvic incidence (PI) on sagittal geometry.In total, 440 volunteers (193 men; 247 women) were enrolled. The spino-pelvic radiographic parameters were measured. The apices of thoracic kyphosis and lumbar lordosis, and the inflection point where the vertebral curvature changes from kyphosis to lordosis were investigated. We analyzed the differences in the sagittal curve shape according to the sex, age, and PI magnitude.On average, the apices of thoracic kyphosis and lumbar lordosis, and the inflection point were located at the levels of the T8/9 intervertebral disc, L3/4 disc, and L1 vertebra, respectively. Significant differences between men and women were observed with respect to the spino-pelvic parameters; however, the positions of the apices were significantly different only with respect to the lumbar apex offsets among individuals in their 70s. The inflectional point and apex of thoracic kyphosis among individuals aged80 years were located significantly anteriorly and caudally in comparison to those among individuals aged69 years. The apex of lumbar lordosis and the inflection point in individuals with high PI were located significantly anteriorly and cranially in comparison to those in individuals with low PI.The apices of thoracic kyphosis and lumbar lordosis, and the inflection point were located at the T8/9 intervertebral disc, L3/4 disc, and L1 vertebra, respectively. The shape of the sagittal spinal curve varied according to age and the magnitude of PI, and these findings cannot be evaluated using the conventional spino-pelvic parameters. Knowledge of standard geometrical spine shape could be useful for spinal deformity treatment in elderly patients.

Study design This was a retrospective analysis of a prospectively collected consecutive case series of patients with adult spinal deformity (ASD). Objective This study aimed to investigate the impact of the geometrical sagittal shape of the corrected spine on the development of proximal junctional kyphosis (PJK). Several studies have documented risk factors for PJK in ASD surgery. Geometrical assessment is vital for evaluating sagittal spinal deformity. It is essential to assess the postoperative geometrical shape of the spine and the location of the correction in the spine to decrease postoperative junctional stress and PJK. Methods Consecutive patients with ASD who underwent corrective fusion with long constructs to the pelvis were included. Patients with neuromuscular disease, congenital and adolescent scoliosis, infection, and spinal tumor were excluded. We investigated the spinopelvic and geometrical parameters of the whole spine. The locations of the thoracic and lumbar apical vertebrae and the inflection vertebrae (IV), where the curvature of the associated adjacent vertebral bodies changes from kyphosis to lordosis, were investigated. The subjects were divided into PJK included patients who underwent revision surgery for junctional failure or with a change in proximal junctional angle ≥ 20°, and non-PJK groups. Results A total of 139 patients (mean age, 69.6 years; range 18-82 years) were included. There were 47 and 92 patients in the PJK and non-PJK groups, respectively. The IV were located significantly cranial and posterior, the lumbar apex were located significantly posterior in the PJK group at the immediate postoperative time points. The significant risk factors for PJK on binary logistic regression were cranial IV and posterior lumbar apical vertebrae. The incidence of PJK in patients with IV at T12 or cranial tends PJK significantly higher (69%) than at L1 or caudal (26%). Conclusions Geometrical spinal shape should be taken into account to reduce the rate of postoperative mechanical complications. Level of evidence Level of evidence III.

OBJECTIVEThe Scoliosis Research Society-22r questionnaire (SRS-22r) has been shown to be reliable, valid, and responsive to change in patients with adult spinal deformity (ASD) undergoing surgery. The minimal clinically important difference (MCID) is the smallest difference in a health-related quality of life score that is considered to be worthwhile or clinically important to the individual. The authors hypothesized that the proportion of patients with ASD achieving an MCID in the SRS-22r score would be different between two culturally different cohorts. The purpose of this study was to compare the proportion of patients with ASD achieving MCID for the SRS-22r domains in North American (NA) and Japanese cohorts.METHODSA total of 137 patients from North America (123 women, mean age 60.0 years) and 60 patients from Japan (56 women, mean age 65.5 years) with at least 2 years of follow-up after corrective spine surgery for ASD were included. Except for self-image, published Japanese MCID values of SRS-22r for ASD were higher (function = 0.90, pain = 0.85, self-image = 1.05, subtotal = 1.05) than the published NA MCID values (function = 0.60, pain = 0.40, self-image = 1.23, subtotal = 0.43).RESULTSThere was a statistically significant improvement in all SRS-22r domain scores at 2 years compared to baseline in both cohorts. Except for mental health (NA = 0.32, Japanese = 0.72, p = 0.005), the mean improvement from baseline to 2 years was similar between the NA and Japanese cohorts. The proportion of patients achieving MCID was higher in North America for function (NA = 51%, Japanese = 30%, p = 0.006), pain (NA = 80%, Japanese = 47%, p < 0.001), and subtotal (NA = 72%, Japanese = 35%, p < 0.001), while there was no significant difference for self-image (NA = 53%, Japanese = 58%, p = 0.454).CONCLUSIONSDespite similar improvements in SRS-22r domain scores from baseline to 2 years postoperatively, the proportion of patients reaching SRS-22r MCID for function, pain, and subtotal after ASD surgery was higher in the NA cohort than in the Japanese cohort. This may imply that patients in North America and Japan may value observed changes in clinical status differently.

Upper instrumented vertebra (UIV) fracture in adult spinal deformity surgery leads serious complications, such as spinal cord injury in 0.5–0.8%. Although tip-apex distance is important for preventing screw cut-out in proximal femoral fracture surgery, this suggest that the screw occupancy rate for bone fragments is also important. The purpose of this study was to investigate how the occupancy rate of pedicle screws (ORPS) affects UIV fracture. Patients with UIV fracture 1 year after surgery were defined as the fracture group (F); others were defined as the no fracture group (NF). ORPS, cut-out of pedicle screw (PS), medications, and bone mineral density were evaluated. Significant differences (P

Study Design: Retrospective cohort study.Purpose: This study aimed to investigate how participation in sporting activity affects patient-reported outcome (PRO), including Neck Disability Index (NDI), in males and females.Overview of Literature: Previously, our study reported that factors with a negative influence on the NDI in females were a lack of sporting activities. However, it was still unclear why it affected poor scores of NDI.Methods: The subjects were 473 volunteers. They were divided into two groups (activity and non-activity) according to participation or non-participation in sporting activities using a self-filled questionnaire. The evaluation items were height, weight, grip strength, bone density, Hospital Anxiety and Depression Scale (HADS) score, standing radiographic parameters, PRO (evaluated by EuroQol-5 dimension [EQ-5D], Oswestry Disability Index [ODI]), and NDI.Results: There were 101 males in the non-activity group and 69 in the activity group and 178 females in the non-activity group and 125 in the activity group. For the males, the evaluation items with significant influence were cervical lordosis (non-activity group:activity group, 17°:22°) and T1 slope minus cervical lordosis (10°:6°, p p

Study design Four-year, longitudinal cohort study. Objective To investigate the effect of original spinal shape on incidental vertebral fractures and to identify the influence of changes in pre- and post-fracture geometrical spinal shape. Summary of background data Clinical evidence demonstrates that vertebral fractures cause spinal kyphosis, morbidities, and deteriorating quality of life in elderly people. However, knowledge of geometrical spinal shapes that affect incidental vertebral fractures is limited. Methods Three hundred and seventeen volunteers underwent whole spine radiography as part of a health screening in both 2012 and 2016. We extracted volunteers with incidental vertebral fracture in 2016. Sex- and age-matched volunteers without vertebral fracture were enrolled as controls. Baseline demographic variables, geometrical spinal shape, and spinopelvic parameters were compared between the two groups. In volunteers with incidental vertebral fracture, we investigated the association between baseline spinal shape and post-fracture shape. Results Twenty-seven volunteers (12 men; mean age 75.4 ± 5.4 and 15 women; mean age 71.6 ± 7.9) with vertebral fracture were enrolled, and 175 volunteers (48 men, 127 women) without vertebral fracture were selected as controls. In men with vertebral fracture, the thoracic kyphosis apex was located significantly more posteriorly and caudally than in those without vertebral fracture. In women with vertebral fracture, the lordosis apex was located significantly more posteriorly and caudally than in those without vertebral fracture. After fractures occurring above the inflexion vertebra, the low anterior apex spine (L5) changed its geometrical shape in that the posterior apex and the inflexion vertebra shifted significantly more posteriorly compared to the high anterior apex spine (L4/5). Conclusions Original geometrical spinal shape affected the occurrence of vertebral fracture, and post-fracture spinal shape depended on the positional relationship between the inflexion vertebra and fractured vertebra. Our study helps to understand the influence of geometrical spinal shape on the risks of vertebral fracture. Level of evidence 3.

Gastroesophageal reflux disease (GERD) is reported as one of the symptoms of adult spinal deformity (ASD). Little is known about the mid- to long-term improvement in GERD symptoms after ASD surgery. Therefore, this retrospective study from prospectively collected database aimed to investigate GERD symptoms in patients for a minimum of 2 years after ASD corrective surgery. Records from 230 patients (mean age: 64 years) who underwent ASD surgery were examined using the frequency scale for the symptoms of GERD (FSSG) questionnaires for the diagnosis of GERD. FSSG scores and radiographic parameters were investigated preoperatively and postoperatively at 6 months and 1, 2, and 5 years. In total, 90 (39%) patients were preoperatively diagnosed with GERD defined by FSSG score ≥ 8 points. Radiographic results showed that the corrective surgeries improved local and global alignments. In the GERD patients, preoperative FSSG scores (16.1 ± 7.3 points) significantly improved to 7.7 ± 7.4 points within 6 months postoperatively (p

Study design Case-control study from a continuous series OBJECTIVES.: To study the impact of perioperative sitting radiographs in adult spinal deformity (ASD) patients and determine whether proximal junctional kyphosis (PJK) can be prevented using preoperative sitting radiograph. Summary of background data Radiographic analysis of ASD comprises standing whole-spine radiography which cannot evaluate the relaxed posture without head-to-foot compensation. Methods Preoperative and postoperative whole-spine standing and sitting radiographs and proximal mechanical complications in surgically treated spinal disorders with a minimum of 1-year follow-up were studued. Whole-spinal alignment was defined by cervical lordosis (CL), sagittal vertical axis (SVA), T1 slope (T1S), thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), and level of kyphotic apex (KA). Proximal mechanical complication was described as a PJK (proximal junctional angle >20°) or reoperation due to proximal junctional failure. Results Surgically treated 113 patients were prospectively investigated. Patients were divided into either the ASD (thoracic to ilium posterior corrective fusion), or non-ASD groups. In the ASD group, ten patients had postoperative PJK, and three revision surgeries were carried out due to PJF with neurological deficit. Comparing standing with sitting positions, CL, TK, and PT became larger, SVA became frontal, LL and SS became smaller, and KA became caudal particularly in the ASD group. Logistic regression analysis demonstrated that the most influenced plumb line for PJK was the upper instrumented vertebra (UIV) to C2 plumb line distance, with a cutoff value of 115 mm for predicting PJK. Conclusions Our findings highlight the usefulness of sitting spinal alignment evaluation, particularly in ASD patients, with maximum effort of thoracic spine and lower extremity compensation at standing. Mechanical complications such as PJK could be predicted using the distance from the planned UIV to the C2 plumb line in preoperative sitting radiographs. Level of evidence 3.

A retrospective study.We aimed to evaluate the impact of mental status on the clinical outcomes of patients with adult spinal deformity (ASD).Limited information is currently available on how preoperative mental status affects postoperative health-related quality of life (HRQOL) in patients with ASD.We enrolled 165 patients with ASD who underwent corrective surgery at a single university hospital between March 2010 and September 2015. We compared Scoliosis Research Society-22r (SRS-22r) and Oswestry Disability Index (ODI) scores using various x-ray parameters at these time points: preoperative period and postoperative 2 years. Additionally, to determine the associations between perioperative complications and mental health disorders, we examined these x-ray parameters: lumbar lordosis, thoracic kyphosis, sacral slope, pelvic incidence, pelvic tilt, sagittal vertical axis (SVA), and T1 pelvic angle (TPA).We found correlations between the preoperative SRS-22r total score and preoperative ODI (r = -0.692, P 0.01) and postoperative ODI (r = -0.443, P 0.01). Preoperative SRS-22r mental domain correlated with preoperative ODI (r = -0.561, P ≤ 0.01) and postoperative ODI (r = -0.315, P ≤ 0.01). Perioperative (preoperative and postoperative) SRS-22r mental domain did not correlate with the postoperative x-ray parameters except for SVA and TPA. Postoperative mental health correlated with early infection (P 0.05), hematoma (P 0.05), deep vein thrombosis (P 0.05), and delirium (P 0.05). Regression analysis revealed that preoperative SRS-22r mental health score correlated with preoperative ODI (P 0.001) and postoperative ODI (P 0.001). The regression coefficient number between preoperative SRS-22r mental health score and perioperative (preoperative and postoperative) ODI improved from -17.3 to -10.2 from preoperative to postoperative periods.Diminished preoperative mental health worsened postoperative HRQOL. Perioperative complications influence postoperative mental status and HRQOL; hence, screening preoperative mental health is important.3.

Study Design: Retrospective multicenter study. Objective: Posterior decompression surgery for cervical spondylotic myelopathy (CSM) and ossification of the posterior longitudinal ligament (OPLL) is a common surgery; however, it can cause postoperative cervical deformity (CD). The purpose of this study was to investigate the risk factors for CD. Methods: The participants were 193 patients underwent laminoplasty or laminectomy for CSM or OPLL. CD was defined as a C2-7 sagittal vertical axis (SVA) ≥ 40 mm or a cervical lordosis angle (CL) ≤ −10°. The participants were divided into 2 groups: NCD (without CD before surgery), CD (with CD before surgery). NCD group was divided based on the presence of CD 1 year after surgery as follows: postoperative CD (PCD) and no PCD (NPCD). Results: There were 153 patients (NCD), 40 (CD), 126 (NPCD), and 27 (PCD). There was significant difference in the number of decompressed lamina (NPCD: PCD = 4.1:4.5), the presence of C2 decompression (2: 11%), and C5 palsy (0: 11%). The risk factors for onset of CD, PCD, and CL ≤ −10° as assessed by multiple logistic regression analysis were preoperative C2-7 SVA ≥ 30 mm (odds ratio [OR]: 19.0), decompression of C2 or C7 lamina (OR 3.1), and preoperative CL ≤ 2° (OR 42.0), respectively. Conclusions: To prevent postoperative CD, it is important to avoid decompression of the C2 or C7 lamina. Moreover, in case with C2-7 SVA ≥ 30 mm or CL ≤ 2° before surgery, it is important to explain the risks and consider adding fusion surgery.

Study design A retrospective study. Purpose To investigate the incidence of iliac screw loosening with a two-rod vs. multi-rod construct and the effect on clinical and radiographic outcomes after surgery for adult spinal deformity (ASD). Overview of literature Multi-rod construct is useful for preventing rod fracture in ASD surgery. However, limited information is available regarding the incidence of iliac screw loosening after corrective fusion surgery using a multi-rod construct. Methods Total 106 patients with ASD (24 men and 82 women; mean age, 68 years) who underwent corrective fusion surgery using bilateral iliac screws and were followed up for at least 1 year were reviewed. The following variables were compared between patients who underwent surgery with a two-rod and multi-rod construct: age, sex, bone mineral density (BMD), fusion level, high-grade osteotomy, L5/S interbody fusion, screw loosening (upper instrumented vertebra [UIV], S1, and iliac), rod fracture, proximal junctional kyphosis, spinopelvic parameters, and Oswestry Disability Index (ODI) score. We also compared patients with and without iliac screw loosening in the multi-rod construct group. Results Of the 106 patients, 55 underwent surgery with a conventional two-rod construct and 51 with a multi-rod construct (three rods in 16, four rods in 35). Iliac and UIV screw loosening was observed in 24 patients (21%) and 35 patients (33%), respectively. The multi-rod group showed significantly higher incidence of iliac and UIV screw loosening and lower incidence of rod fracture. Patients with iliac screw loosening had a lower BMD than those without screw loosening; however, no significant differences were observed in the spinopelvic parameters or the ODI score. Conclusions The use of multi-rod constructs led to a higher incidence of junctional screw loosening than the use of conventional two-rod constructs, especially in patients with osteoporosis. Iliac screw loosening did not affect sagittal alignment or clinical outcome in the short term.

OBJECTIVEIntraoperative neuromonitoring may be valuable for predicting postoperative neurological complications, and transcranial motor evoked potentials (TcMEPs) are the most reliable monitoring modality with high sensitivity. One of the most frequent problems of TcMEP monitoring is the high rate of false-positive alerts, also called “anesthetic fade.” The purpose of this study was to clarify the risk factors for false-positive TcMEP alerts and to find ways to reduce false-positive rates.METHODSThe authors analyzed 703 patients who underwent TcMEP monitoring under total intravenous anesthesia during spinal surgery within a 7-year interval. They defined an alert point as final TcMEP amplitudes ≤ 30% of the baseline. Variations in body temperature (maximum − minimum body temperature during surgery) were measured. Patients with false-positive alerts were classified into 2 groups: a global group with alerts observed in 2 or more muscles of the upper and lower extremities, and a focal group with alerts observed in 1 muscle.RESULTSFalse-positive alerts occurred in 100 cases (14%), comprising 60 cases with global and 40 cases with focal alerts. Compared with the 545 true-negative cases, in the false-positive cases the patients had received a significantly higher total propofol dose (1915 mg vs 1380 mg; p < 0.001). In the false-positive cases with global alerts, the patients had also received a higher mean propofol dose than those with focal alerts (4.5 mg/kg/hr vs 4.2 mg/kg/hr; p = 0.087). The cutoff value of the total propofol dose for predicting false-positive alerts, with the best sensitivity and specificity, was 1550 mg. Multivariate logistic analysis revealed that a total propofol dose > 1550 mg (OR 4.583; 95% CI 2.785–7.539; p < 0.001), variation in body temperature (1°C difference; OR 1.691; 95% CI 1.060–2.465; p < 0.01), and estimated blood loss (500-ml difference; OR 1.309; 95% CI 1.155–1.484; p < 0.001) were independently associated with false-positive alerts.CONCLUSIONSIntraoperative total propofol dose > 1550 mg, larger variation in body temperature, and greater blood loss are independently associated with false-positive alerts during spinal surgery. The authors believe that these factors may contribute to the false-positive global alerts that characterize anesthetic fade. As it is necessary to consider multiple confounding factors to distinguish false-positive alerts from true-positive alerts, including variation in body temperature or ischemic condition, the authors argue the importance of a team approach that includes surgeons, anesthesiologists, and medical engineers.

Retrospective study of postoperative outcomes of adult spinal deformity (ASD) surgery.To clarify the differences in postoperative outcomes depending on the presence or absence of thoracic compensatory changes among patients with a T1 slope (TS) more than 40°.Loss correction after ASD surgery is more likely to occur when preoperative TS is more than 40°. When preoperative TS is more than 40°, some cases involve compensatory changes in the thoracic spine and decreased thoracic kyphosis (TK); others involve increased TK without compensatory changes.Seventy-nine patients with TS more than 40° who underwent ASD surgery were enrolled and separated into compensated and noncompensated groups (group C: TK40°; group NC: TK ≥40°). Radiographic parameters obtained by whole-spine standing x-ray, the Oswestry Disability Index (ODI), and Scoliosis Research Society-22 (SRS-22) questionnaire were assessed.There were 41 patients in group C and 38 patients in group NC. Preoperative significant differences in TS did not disappear after surgery (preoperative TS: group C and group NC = 46° and 55°, P 0.001; just after surgery: group C and group NC = 27° and 40°, P 0.001; 2 years later: group C and group NC = 34° and 47°, P 0.001). There were no significant differences in ODI and all domains of the SRS-22 before surgery. However, 2 years after the surgery, ODI (38%), pain (3.5), self-image (3.0), and total (3.2) values of the SRS-22 for group NC were significantly worse than those (28%, 4.0, 3.4, and 3.5, respectively) for group C (P 0.05).Changes in the thoracic spine (TS and TK40°) result in poor postoperative outcomes. Extending the upper instrumented vertebra (UIV) to the upper thoracic spine must be considered. Even when TS is more than 40°, TK less than 40°, and upper instrumented vertebra set to the lower thoracic level result in good postoperative outcomes.3.

Introduction: There is currently a lack of translatable, preclinical models of low back pain (LBP). Chymopapain, a proteolytic enzyme used to treat lumbar intervertebral disc (IVD) herniation, could induce discogenic LBP. The current study developed a behavioral model of discogenic LBP in nonhuman primates. Significant brain activation is observed in clinical LBP. Thus, the current study also sought to define brain activation over time in a macaque with discogenic LBP. Methods: Responses to pressure applied to the back at L4/L5 were measured in eight adult male Macaca fasciculata using a pressure algometer. The nucleus pulpous of the IVD between L4 and L5 was aspirated and chymopapain (1 mg/mL) was injected under fluoroscopic guidance (n = 2). In two macaques, the nucleus pulpous was only aspirated. Brain activation in response to pressure applied to the lower back was assessed using a 3.0T magnetic resonance imaging scanner in four macaques before and 1, 3, 9, and 14 days after treatment. Results: The mean (±SD) response pressure before treatment was 1.4 ± 0.1 kg. One day after chymopapain treatment, the response pressure decreased to 0.6 ± 0.05 kg (P < 0.01), suggestive of pressure hypersensitivity. Over time, the pressure thresholds following chymopapain treatment gradually returned to normal. Following aspiration only, the response pressure was 1.4 ± 0.05 kg, which was not significantly different from the uninjured controls. There was activation of the secondary somatosensory cortex and insular cortex one and three days after chymopapain treatment; there was no activation following aspiration only. Conclusions: Enzymatic treatment of the nucleus pulpous leads to acute LBP and pressure-evoked activation in pain-related brain areas. The current model of discogenic LBP parallels clinical LBP and could be used to further elaborate the mechanism of acute LBP.

Study design A retrospective study of postoperative delirium after adult spinal deformity (ASD) surgery. Objective To identify the risk factors of post-ASD surgery delirium, including nutritional state before surgery. Summary of background data Recently, malnutrition was reported as one of the risk factors of delirium. The prognostic nutritional index (PNI) and controlling nutritional status index (CONUT) scores are simple methods of nutritional evaluation. However, there are no reports that verify that delirium is related to the PNI and CONUT score in patients who have undergone ASD surgery. Methods A consecutive 319 patients who underwent ASD surgery were divided into a delirium group (group D) or nondelirium group (group ND). Preoperative risk factors, including PNI, were assessed. Results Group D consisted of 30 patients and group ND consisted of 289 patients. There was significant difference in age (group D:group ND = 73:62, P = 0.000), serum albumin (4.2:4.3, P = 0.028), operative time (422:395 min, P = 0.029), PNI score (49:52, P = 0.011), and CONUT score (1.7:1.1, P = 0.046). Using multiple logistic regression analysis, we found significant risk factors for delirium to be age (P = 0.006, odds ratio = 1.11, 95% confidence interval = 1.03-1.19) and PNI (P = 0.003, odds ratio = 0.87, 95% confidence interval = 0.79-0.96). A receiver operating characteristic curve showed that the cut-off value of PNI and age for delirium were 49.7 and 68.5 years, respectively. Conclusion The risk factors of postoperative delirium after ASD surgery were PNI less than 49.7 and age more than 68.5 years. Patients who undergo ASD surgery beyond these preoperative cut-off values should be cautioned about delirium and be required to provide adequate informed consent. Level of evidence 3.

In the current study, we aimed to analyze the lipid changes in the dorsal root ganglion (DRG) after sciatic nerve transection (SNT) using matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS). We found that the arachidonic acid-containing phosphatidylcholine (AA-PC), PC(16:0/20:4) largely increased, while PC(16:0/18:1), PC(18:0/18:1) and phosphatidic acid (PA)(36:2) levels largely decreased in the DRG following nerve injury. Previous studies show that the increase in PC(16:0/20:4) was associated with neuropathic pain and that decrease in PC(16:0/18:1), PC(18:0/18:1), and PA(36:2) were due to producing lysophosphatidic acid (LPA), an initiator for neuropathic pain. These results suggest that the lipid changes in DRG after SNT could be the result of changes for the cause of neuropathic pain. Thus, blocking of LPA could be potential for treatment of neuropathic pain.

Study design Retrospective study. Purpose To calculate the minimum clinically important difference (MCID) for total and individual domains of the Oswestry Disability Index (ODI) and assess score distribution and changes over time in surgically treated adult spinal deformity (ASD) patients. Overview of literature Despite the common use of ODI for assessing ASD, there are no robust studies defining MCID values for this index. Methods This study included 240 consecutive ASD patients with a minimum of 2 years of follow-up. We calculated MCID values for total and individual ODI domains using all or part of the Scoliosis Research Society-22R questionnaire as anchors. Using current MCID values, we measured the acquisition rates in patients who acquired MCID at follow-up in both total and individual ODI domains. Differences in pathology, age, and locations of the upper and lower instrumented vertebrae were analyzed. Results MCID of the total ODI score was 11%, with an area under the curve of 0.737. Each domain ranged from 0 to 2, with 1 being the most common value. In the pain and standing domains, >60% of the patients acquired MCID, although acquisition rates of the personal care, lifting, sleep, and sexual activity domains were relatively low (20%-35%). Patients with MCID had more radiographic improvement in lumbar lordosis, sagittal vertical axis, and T1 pelvic angle than those without MCID (p Conclusions To our knowledge, this is the first study to describe MCID of ODI (11%) after ASD surgery. In the pain and standing domains, most patients acquired MCID although the rates of acquisition of MCID in the personal care, lifting, sleep, and sexual activity domains were low. Spine surgeons should counsel their patients regarding the benefits and setbacks of ASD surgery.

Objective We investigated the relationship between cross-sectional area (CSA) of paravertebral muscle and trunk tilt at standing and walking in adult spinal deformity (ASD) surgery. Summary of Background Data Although the importance of back muscles for the development of spinal kyphosis was well described, the influence on maintaining the sagittal balance was unclear. Methods Forty-five female patients (mean age, 68.8 years) with ASD were studied. We measured sagittal vertical axis [SVA], pelvic tilt [PT], and pelvic incidence–lumbar lordosis [PI-LL]) by lateral spine radiograph. For the assessment of trunk tilt standing-trunk tilt angle (STA) by lateral standing radiograph, gait-trunk tilt angle (GTA) by lateral gait images, and the increasing trunk tilt angle (ITA) by subtracting the STA from the GTA were calculated. Using L1/2 and L4/5 axial MRI, the CSAs of bilateral multifidus muscles (MF) and elector spinae (ES) removed fat by Image J software were calculated. We examined the correlation between trunk tilt angle (STA, GTA, and ITA) and spinopelvic parameters (SVA, PT, and PI minus LL) and also the correlation among muscle CSA, trunk tilt angle (STA, GTA, and ITA), and Oswestry Disability Index (ODI). Results The mean STA, GTA, and ITA were 4.2°, 13.0°, and 8.8°, respectively. The CSAs of back muscles were 278 mm 2 at L1/2 MF, 1,687 mm 2 at L1/2 ES, 636 mm 2 at L4/5 MF, and 1,355 mm 2 at L4/5 ES, respectively. Trunk tilt angle had significant relations with spinopelvic parameters. Concerning about muscle CSA, significant correlations were observed between STA and L4/5 MF (r = −0.517), GTA and L1/2 ES (r = −0.461) and L4/5 MF (r = −0.476), and ITA and L1/2 ES(r = −0.429). ODI showed significant correlation with STA and GTA. Conclusions Paravertebral muscles were crucial to keep upright posture during walking as well as standing.

Mini abstractPatients with poor preoperative health-related quality of life were more likely to achieve functional improvement after extensive corrective fusion surgery for adult spinal deformity. Postoperative improvement to sagittal vertical axis increased the likelihood of MCID for the SRS-22r Subtotal domain., Structured abstractStudy design: Retrospective longitudinal cohort study.Objective: This study aimed to elucidate factors affecting the likelihood of achieving minimum clinically important difference (MCID) to patient-reported outcomes defined by the Scoliosis Research Society-22r (SRS-22r) among patients with adult spinal deformity (ASD) who underwent extensive corrective fusion surgery from the thoracic spine to the pelvis.Summary of background data: Achieving MCID for SRS-22r parameters was a measure of surgical efficacy. Patient characteristics and surgical and radiographic factors that affect the likelihood of achieving MCID for SRS-22r parameters are unknown.Methods: Data from patients with ASD who underwent extensive corrective fusion surgery from the thoracic spine to the pelvis during 2010-2016 were retrospectively reviewed. Data from a total of 167 patients with ≥2 years of follow-up were included. Multivariate analysis was used to investigate factors associated with the likelihood of achieving MCID for each of the SRS-22r domains (Function, Pain, Subtotal) 2 years after surgery. The following MCID values were used: 0.90 for Function, 0.85 for Pain, and 1.05 for the Subtotal.Results: MCID achievement rate was 36.5% for Function, 46.1% for Pain, and 44.3% for the Subtotal domain. In multivariate analysis, preoperative SRS-22r Function (OR=0.204, 95% CI, 0.105-0.396) increased the likelihood of achieving MCID for SRS-22r Function. Preoperative SRS-22r Subtotal (OR=0.211, 95% CI, 0.107-0.413), preoperative pelvic tilt (OR=1.072, 95% CI, 1.012-1.136), preoperative pelvic incidence minus lumbar lordosis (OR=0.965, 95% CI, 0.934-0.997), and postoperative sagittal vertical axis (OR=0.985, 95% CI, 0.974-0.995) affected the likelihood of achieving MCID for the SRS-22r Subtotal.Conclusions: Patients with poor preoperative health-related quality of life were more likely to achieve improvement in SRS-22r parameters after extensive corrective fusion surgery for ASD. Achieving postoperative sagittal alignment increased the likelihood of achieving MCID for the SRS-22r Subtotal domain., Key points• Patients with poor preoperative health-related quality of life were more likely to achieve improvement in SRS-22r parameters after extensive corrective fusion surgery for adult spinal deformity.• Postoperative improvement to sagittal vertical axis increased the likelihood of MCID for the SRS-22r Subtotal domain.• Revision surgery negatively affected the likelihood of meaningful functional improvements; therefore, minimizing the risk of revision surgery is important.

Study design A retrospective case series. Objective To introduce the prevention of total hip arthroplasty (THA) dislocation using an implant impingement simulation after spinal corrective fusion and to verify the outcomes. Summary of background data A high dislocation rate was found among patients who underwent spinal deformity corrective fusion with prior total hip arthroplasty (THA). To avoid dislocation, an appropriate position of the stem and cup is important, but the pelvic inclination may change after corrective fusion for spinal deformity. Methods Twelve consecutive patients [2 men, 10 women; average age, 72.1 (range, 55-81) years during spine surgery] with prior THA were included. Data were retrospectively retrieved from a single-center's prospectively collected database of adult spinal deformity operation. Before surgery, anterior implant impingement simulation in THA was performed using computed tomography-based software. The tolerable pelvic tilt (PT) in which the anterior implant impingement occurred in the hip at the 120° flexion position was measured. The lumbar lordosis angle was deliberately reduced during spinal surgery according to the tolerable PT. The effect of the implant impingement simulation was verified by comparison with patients who underwent surgery prior to simulation (before 2014). Results THA dislocation occurred in six patients; four of five (80%) in the non-simulation, and two of seven (28.6%) in the simulation group. The difference between the preoperative and tolerable PT angles were -25° to 33°, and three patients had negative angles. In these three patients, the risk of anterior impingement and THA dislocation significantly increased with correction of lumbar lordosis if the PT was anterior. Two patients experienced repeated THA dislocation with postoperative and tolerable PT angle differences of 2 ° and -23 ° CONCLUSIONS.: Our simulation of anterior implant impingement and subsequent adjustment of the degree of spinal correction was useful to prevent dislocation. However, this method did not prevent dislocation in some patients. Level of evidence 4.

Attenuation of the secondary injury of spinal cord injury (SCI) can suppress the spread of spinal cord tissue damage, possibly resulting in spinal cord sparing that can improve functional prognoses. Granulocyte colony-stimulating factor (G-CSF) is a haematological cytokine commonly used to treat neutropenia. Previous reports have shown that G-CSF promotes functional recovery in rodent models of SCI. Based on preclinical results, we conducted early phase clinical trials, showing safety/feasibility and suggestive efficacy. These lines of evidence demonstrate that G-CSF might have therapeutic benefits for acute SCI in humans. To confirm this efficacy and to obtain strong evidence for pharmaceutical approval of G-CSF therapy for SCI, we conducted a phase 3 clinical trial designed as a prospective, randomized, double-blinded and placebo-controlled comparative trial. The current trial included cervical SCI [severity of American Spinal Injury Association (ASIA) Impairment Scale (AIS) B or C] within 48 h after injury. Patients are randomly assigned to G-CSF and placebo groups. The G-CSF group was administered 400 μg/m2/day × 5 days of G-CSF in normal saline via intravenous infusion for five consecutive days. The placebo group was similarly administered a placebo. Allocation was concealed between blinded evaluators of efficacy/safety and those for laboratory data, as G-CSF markedly increases white blood cell counts that can reveal patient treatment. Efficacy and safety were evaluated by blinded observer. Our primary end point was changes in ASIA motor scores from baseline to 3 months after drug administration. Each group includes 44 patients (88 total patients). Our protocol was approved by the Pharmaceuticals and Medical Device Agency in Japan and this trial is funded by the Center for Clinical Trials, Japan Medical Association. There was no significant difference in the primary end point between the G-CSF and the placebo control groups. In contrast, one of the secondary end points showed that the ASIA motor score 6 months (P = 0.062) and 1 year (P = 0.073) after drug administration tend to be higher in the G-CSF group compared with the placebo control group. Moreover, in patients aged over 65 years old, motor recovery 6 months after drug administration showed a strong trend towards a better recovery in the G-CSF treated group (P = 0.056) compared with the control group. The present trial failed to show a significant effect of G-CSF in primary end point although the subanalyses of the present trial suggested potential G-CSF benefits for specific population., Koda et al. present the results of a randomized phase 3 trial comparing granulocyte colony-stimulating factor versus placebo in patients with acute spinal cord injury. While the primary endpoint was not met, a sub-analysis revealed a trend towards superior efficacy of G-CSF versus placebo in an elderly population.

Though there are several reports on the high dislocation rates following total hip arthroplasty (THA) before or after spinal surgery, the literature specific to extensive spinal corrective fusion with pelvic fixation for adult spinal deformity is limited. This study determined the rate and risk of hip dislocation after THA and extensive spinal corrective fusion. We retrospectively analyzed the data of 23 adults (27 hips) who underwent both extensive spinal corrective fusion with pelvic fixation and THA between 2010 and 2018. Surgery-related characteristics were investigated from medical records, while standing anteroposterior pelvic radiographs and lateral spinal radiographs were used to measure spinal alignment parameters and THA acetabular orientation. Patients were grouped based on the occurrence of dislocation, and the rate and risk of dislocation were compared. The rate of THA dislocations was extremely high—22% (6 of 27 hips) of patients. All dislocations occurred posteriorly in patients with prior THAs that were performed using the posterior approach. The pelvic tilt was significantly greater in patients with THA dislocations (p = 0.02) than in those without. Cup radiographic anteversion in the supine (p = 0.02) and standing (p = 0.05) positions was significantly smaller in patients with dislocations than in those without. Total hip arthroplasty concurrent with extensive spinal corrective fusion with pelvic fixation for adult spinal deformity has an extremely high rate of posterior hip dislocation. The posterior surgical approach and prior THA were high risk factors for dislocation. Hip and spine surgeons need focused pre-surgical planning to account for this risk.

L5 pedicle subtraction osteotomy (PSO) is a demanding technique; thus, PSOs are usually performed at the L3/L4 level to correct the lack of lumbar lordosis. Mid- to long-term improvements in clinical outcomes after L5 PSO are unknown. We aimed to determine the efficacy and safety of L5 PSO for rigid kyphosis deformities. We retrospectively reviewed the records of 57 patients with a rigid kyphosis deformity (mean age: 68 years) who underwent extensive corrective surgery incorporating PSO with a > 2-year follow-up. Radiographic parameters, postoperative complication rates, and the Oswestry Disability Index (ODI) scores were compared in the L5, L4, and L1-3 PSO groups preoperatively and at 1, 2, and 5 years postoperatively. There were 12, 25, and 20 patients in the L5, L4, and L1-3 PSO groups, respectively. Significant between-group differences were found in preoperative L4–S1 lordosis (L5:L4:L1-3 PSO groups = − 8.9°:8.9°:16.2°, P

Background. Sagittal spino-pelvic malalignment in patients with chronic low back pain (CLBP) have been reported in the past, which may also affect cervical spine lesions. The purpose of this study is to investigate the cervical alignment in patients with CLBP.Method. Of the patients who visited an orthopedic specialist due to low back pain lasting more than three months, 121 cases (average 71.5 years old, 46 male and 75 female) with whole standing spinal screening radiographs were reviewed (CLBP group). Cervical parameters included cervical lordosis (CL), C2-C7 sagittal vertical axis (C2-7 SVA), and the T1 slope minus CL (T1S-CL). Cervical spine deformity was defined as C2-7 SVA>4cm, CL

Retrospective study. To investigate pelvic obliquity prevalence and its coronal alignment effects in patients with adolescent idiopathic scoliosis (AIS). Pelvic obliquity observed on standing radiographs could affect coronal alignment; however, its incidence or relationship with coronal alignment remains unclear. Data of 141 patients with AIS (11 men, 130 women; mean age, 14.2 years) were retrospectively analyzed. Pelvic obliquity (pelvic coronal obliquity angle (PCOA) value ≥ 3°) was evaluated on standing radiographs; PCOAs were classified into two groups: right-upward and left-upward. Cobb angle and flexibility of proximal thoracic, main thoracic, thoracolumbar/lumbar curve, radiographic shoulder height (RSH), L4 tilt, and coronal balance were measured. Iliac crest and femoral head height differences were measured to evaluate correlations between pelvic obliquity and leg length discrepancy. We compared patients with and without pelvic obliquity according to Lenke classifications. Among 141 patients, 33 (23%) showed pelvic obliquity: 12 were type 1, 3 were type 2, 1 was type 3, 13 were type 5, and 4 were type 6. Right-upward obliquity was observed in 25 patients (76%), all B or C curves; left-upward obliquity was observed in 8 (24%) and most were lumbar modifier A curves. PCOA and iliac crest height difference correlated with femoral head height difference. Among patients with Lenke type 1 with and without pelvic obliquity, those with right-upward pelvic obliquity showed significantly greater absolute RSH values, while those with left-upward pelvic obliquity showed significant smaller absolute RSH values. Among patients with Lenke types 5 and 6, those with pelvic obliquity showed significantly greater L4 tilt absolute values. Pelvic obliquity was frequently observed in patients with AIS, especially lumbar scoliosis. Right–upward pelvic obliquity influenced by lumbar curves promoted shoulder imbalance and left-upward obliquity compensated for shoulder imbalance in Lenke type 1. Level 3.

Background Spinal shortening osteotomy (SSO) reduces the tension indirectly in the spinal cord and minimizes perioperative complications. However, the most effective and safe length to which the spine can be shortened is still unknown. In our practice, we use somatosensory-evoked potentials, motor-evoked potentials, and intraoperative ultrasonography when performing SSO. This study aimed to introduce the clinical outcomes of our SSO technique for tethered cord syndrome (TCS) in adults. Methods This retrospective study included 7 adult patients (2 males and 5 females) with TCS treated between December 2010 and December 2018. The average age and average preoperative duration were 40 and 5 years, respectively. All patients received SSO with somatosensory-evoked potentials, motor-evoked potentials, and ultrasonography. After surgery, all patients were followed for an average of 4 years. Results The mean operation time was 328 (284–414) min for SSO. The mean blood loss was 828 ml (501–1252 ml). Postoperative bony fusion was confirmed in all patients. Postoperative computed tomography (CT) demonstrated an average of 16 mm (11–20 mm) of spinal column shortening, compared with preoperative CT. Clinical improvements were obtained in all 7 cases, and there was no case of exacerbation. An indicator of shortening is that the ultrasonography gives pulsation and relaxation of the spinal cord. There were no abnormalities observed while monitoring the spinal cord. Conclusions Spinal shortening should be done under somatosensory-evoked potentials, motor-evoked potentials, and intraoperative ultrasonography to obtain safe and sufficient shortening.

Background Diffuse idiopathic skeletal hyperostosis (DISH) is associated with increasing age, obesity, and diabetes mellitus. However, little is known about the clinical impacts of DISH on physical function and spinal deformity in elderly populations. The purpose of this study was to elucidate the influence of DISH on physical function, spinal deformity, and health-related quality of life (HRQOL) in elderly populations. Methods We enrolled 504 volunteers (203 men and 301 women, mean age 74.0 years). Height, weight, body mass index (BMI), blood pressure, grip strength, one-leg standing time, sit-and-reach, functional reach, and bone mineral density (BMD) were measured. Using whole spine standing X-rays, the prevalence, location, and numbers of fused vertebra of DISH and spinopelvic parameters were measured. HRQOL measures, including the Oswestry Disability Index and the EuroQuol-5D were also obtained. We compared DISH subjects with control subjects of age and sex matching. We compared DISH subjects in the thoracic spine (T-DISH) to those in the thoraco-lumbar spine (TL-DISH). Results DISH occurred more frequently in men (14.3%) than in women (4.3%). The mean age was significantly higher of subjects with DISH than of those without DISH. The mean number of fused vertebra by DISH was 5.5 ± 1.5, and T-DISH was observed in 57% cases. DISH group showed greater body weights, BMIs, blood pressures, and BMD in the lumbar spine compared to the control group. No inter-group differences were observed in physical function, HRQOL and spinopelvic parameters. Subjects with TL-DISH had significantly lower values of sit-and-reach and functional reach than those with T-DISH. Conclusions Subjects with DISH showed greater body weights, BMIs, blood pressures, and BMD compared to age- and sex-matched controls, while physical function, spinal alignment, and HRQOL were comparable between groups.

Introduction: Correction of lumbar lordosis is the primary goal of surgical treatment of adult spinal deformity. However, only limited research has evaluated the effects of this correction on the adaptive curvature of the thoracic spine. The purpose of this study is to evaluate the change in thoracic curvature after corrective surgery to restore lumbar lordosis in patients with adult spinal deformity. Methods: We completed a retrospective analysis of the radiological data of 65 patients, 50 years old, who underwent corrective surgery of lumbar spine lordosis from any level below T8 to the ilium. Patients with insufficient correction, defined by a pelvic incidence minus lumbar lordosis angle (PI-LL) > 10°, were excluded, with the data of 43 patients included in the analysis. The following radiological measures of spinal alignment were measured at three time points, preoperatively, on the first day of standing postoperatively and at 2 years post-surgery: sagittal vertical axis (SVA), lumbar lordosis (LL), thoracic kyphosis (TK), pelvic tilt (PT), and PI-LL. Results: Postoperative change in TK was correlated to preoperative TK and age. The increase in TK was larger for patients 75 years, TK remained largely unchanged at 37.8° just after surgery but increased substantively to 50.1° at the 2-year follow-up. The postoperative change in TK immediately after surgery was determined using equation “predict change in TK = −0.21 × age − 0.6 × preoperative TK + 41.8” by multiple regression analysis. Conclusions: Reciprocal change in TK after lumbar spine correction is correlated to preoperative TK and age.

Ethnic differences in spino-pelvic parameters among a healthy population are poorly defined in the literature. The purpose of this study was to document sagittal spino-pelvic parameters in a sample of African Americans and to compare them with previously reported data for Caucasians and Asians. African American individuals without spine pathology who had standing lateral radiographs were identified. Radiographs were measured to determine the following parameters: lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS). Data of adult subjects were compared with those previously published for Caucasians (n = 709) and Asians (n = 312). These measurements (LL, PI, PT, and SS) obtained for the 36 African American subjects aged 18 years or older [15 men and 21 women; mean age 26.6 ± 8.7 range (18–53)] The mean LL, PI, PT and SS values were 57.2°, 57.7°, 15.9° and 41.4°, respectively. A comparative analysis showed the means values for PI was greater in the African American than in Caucasian (57.7° vs. 52.6°, p = 0.007), and than in Asian (57.7° vs. 48.7°, p

Study design Retrospective study. Purpose We aimed to determine the utility of transcranial motor evoked potential (TcMEP) monitoring for the detection of intraoperative nerve root injury. Overview of literature Intraoperative neuromonitoring is important for the prediction of neurological injuries or postoperative paralysis. Nerve root injury can develop as a complication of adult spinal deformity (ASD) surgery. Methods We analyzed 295 patients who underwent ASD surgery using multi-channel TcMEP monitoring between 2010 and 2016 (58 men, 237 women; median age, 68 years; follow-up period ≥1 year). We defined the alarm point as a TcMEP amplitude l30% of that at baseline, and nerve root injury as meeting the focal TcMEP alerts shortly following surgical procedures with the presence of postoperative motor deficits in the selected muscles. Patients were classified into two groups, as those with nerve root injury and those with true-negatives. Results Seven patients (2.4%) exhibited neurological events related to nerve root injury, comprising six true-positive and one falsenegative cases. TcMEP monitoring from multiple myotomes was effective in detecting nerve root injury. Compared to the 248 truenegative cases, the seven cases of nerve root injury were associated with significantly different preoperative pelvic tilt (PT) values, sacral slope values, and degree of change in PT. The cutoff for the degree of change in PT for predicting nerve root injury, with the best sensitivity and specificity, was 17.5°. Multivariate logistic analyses revealed that a change of g17.5° in PT (odds ratio, 17.5; 95% confidence interval, 1.994-153.560; p =0.010) was independently associated with intraoperative nerve root injury. Conclusions Multi-channel TcMEP monitoring may be useful for detecting nerve root injuries. A change in PT of g17.5° may be a significant risk factor for neurological events related to intraoperative nerve root injury.

The Scoliosis Research Society-22r (SRS-22r) has been shown to be reliable, valid and responsive to change in patients with adult spinal deformity (ASD) undergoing surgery. The minimum clinically important difference (MCID) quantifies a threshold value of improvement that is clinically relevant to the patient. Health-related quality of life scores depend on age. The purpose of this study was to assess MCID threshold values stratified by age for SRS-22r domains in patients with ASD undergoing surgical correction.We identified a consecutive series of 184 Japanese ASD patients who completed the SRS-22r and Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) preoperatively and 1 year postoperatively. Effectiveness as measured on the JOABPEQ was used as the anchor to determine MCID for the Function, Pain, and Mental health domains using receiver-operating-characteristic (ROC) curve analysis. We performed MCID analysis stratified by age (70 or ≥70).Mean preoperative SRS-22r Function score was 2.69 improving to 3.23 at postoperatively (p 0.001). Mean preoperative SRS-22r Pain score was 3.04 improving to 3.78 at postoperatively (p 0.001). Mean preoperative SRS-22r Mental health score was 2.72 improving to 3.25 at postoperatively (p 0.001). There was a statistically difference in change in domain score between "not effective" and "effective" (p 0.001). The ROC curve analysis methods yielded MCID values of 0.58 for Function, 0.55 for Pain, and 0.70 for Mental health domains. There was difference of MCID value for Function and Mental health domain between aged70 and ≥70; 0.78 and 0.55 for Function; 0.70 and 0.48 for Mental health.Results of this study showed that MCID threshold values for SRS-22 Function and Mental health domains in older than 70 was lower than in younger than 70, potentially implying that older patients have lower expectation.

STUDY DESIGN Longitudinal cohort. OBJECTIVE The present study aimed to document changes in posture and lower extremity kinematics during gait in patients with adult spinal deformity (ASD) after extensive corrective surgery. SUMMARY OF BACKGROUND DATA Standing radiographic parameters are typically used to evaluate patients with ASD. Previously, preoperative walking and standing posture discrepancy were reported in patients with ASD. We did not include comparison between before and after surgery. Therefore, we thought that pre- and postoperative evaluations for patients with ASD should include gait analysis. METHODS Thirty-nine patients with ASD (5 men, 34 women; mean age, 71.0 ± 6.1) who underwent posterior corrective fixation surgeries from the thoracic spine to the pelvis were included. A 4-m walk was recorded and analyzed. Sagittal balance while walking was calculated as the angle between the plumb line on the side and the line connecting the greater trochanter and pinna while walking (i.e., the gait-trunk tilt angle [GTA]). We measured maximum knee extension angle during one gait cycle, step length (cm), and walking speed (m/min). Radiographic parameters were also measured. RESULTS The mean GTA and the mean maximum knee extension angle significantly improved from 13.4° to 6.4°, and -13.3° to -9.4°(P

This study aimed to investigate the treatment effects of low-intensity pulsed ultrasound (LIPUS) on progressive-stage spondylolysis. Spondylolysis is a stress fracture of the pars interarticularis. Based on the results of computed tomography, spondylolysis was classified into three categories: early, progressive, and terminal. Bone healing was prolonged or not obtained in progressive-stage spondylolysis. The progression of spondylolysis to nonunion has been associated with an increased incidence of spondylolisthesis. To prevent these clinical conditions, achieving bony healing of the spondylolysis site should be the goal of treatment. 15 consecutive pediatric patients with progressive-stage spondylolysis (defects) with MRI high-signal change were analyzed. Nine patients were treated conservative treatment including avoidance of any sport activity and the use of a brace during treatment (conventional). Six patients were treated using LIPUS everyday during treatment in addition to conservative treatment. Approximately every 1.5 months, bone healing was evaluated via CT. Cases that retained defects after 4.5 months were defined as nonunion. Two patients dropped out during the study period. A total of 13 patients (mean 14.6 ± 2.5 years) from the database met with 19 interarticularis defects. The bone union rate in LIPUS group was significantly higher than that in conventional group (66.7 vs. 10.0%, p = 0.020). The treatment period to bone union was 3.8 months and 2.7 ± 0.3 months in conventional and LIPUS groups. This study revealed that LIPUS treatment might be effective for bone union in patients with progressive-stage spondylolysis with MRI high-signal change. 4.

STUDY DESIGN Retrospective case series. OBJECTIVE The present study aimed to determine the characteristics of patients with adult spinal deformity (ASD) with a discrepancy between standing and walking postures. SUMMARY OF BACKGROUND DATA Standing radiographic parameters are typically used to evaluate patients with ASD. Patients with ASD with relatively good sagittal alignment on standing radiography have, however, been reported to walk with a forward trunk tilt. METHODS Patients with ASD (n = 93; 13 men, 80 women; mean age, 65.0 yr) who underwent corrective surgery and preoperative gait analysis at our hospital between 2011 and 2013 were included. Spine radiographs and gait analysis data were acquired preoperatively. Standing-trunk tilt angle (STA) on lateral standing x-ray, gait-trunk tilt angle (GTA) from lateral gait images, and radiographic parameters of the spine and pelvis (lumbar lordosis [LL], pelvic tilt, and sagittal vertical axis) were measured. We calculated the increasing trunk tilt angle (ITA), by subtracting the STA from the GTA, for use as an index of discrepancy between standing posture and sagittal balance during walking. We examined the relation between radiographic parameters and ITA. RESULTS The mean preoperative STA and GTA were 3.5° and 11.1°, respectively. The mean preoperative ITA, which represents the degree of discrepancy between standing posture and sagittal balance during walking, was 7.6°. The mean preoperative sagittal vertical axis, LL, pelvic incidence (PI), pelvic tilt, and PI minus LL were 102.6 mm, 20.3°, 52.9°, 32.1°, and 32.6°, respectively. The PI minus LL mismatch was positively correlated with the ITA (R = 0.237, P = 0.023). In particular, patients with ASD with a PI minus LL mismatch of more than 40° had a significantly greater ITA. CONCLUSION Gait analysis revealed that a preoperative standing-walking discrepancy is associated with severe PI - LL mismatch. LEVEL OF EVIDENCE 4.

BackgroundCondoliase is a novel, potent chemonucleolytic drug available for clinical use for lumbar disc herniation (LDH) in Japan. The aim of this study was to assess the clinical outcome of condoliase therapy in patients with LDH, as well as factors affecting the clinical outcome.MethodsWe enrolled patients with LDH who were receiving condoliase injection. The following baseline data were collected: symptom duration; herniation level and type; T2 signal intensity of herniation; adverse events; rates of spondylolisthesis, posterior intervertebral angle of ≥5°, and vertebral body translation of ≥3 mm. Change in disc height, disc degeneration, herniation size, visual analogue scale (VAS) for leg and back pain, and Oswestry Disability Index (ODI) were evaluated at the baseline, and 3-month follow-up. These data were compared between patients with efficacious (VAS improvement of ≥20 mm; group E) and inefficacious (VAS improvement

Study design A retrospective case series. Objective To clarify the mid-term results of extensive spinal fusion surgery in patients with Parkinson disease (PD) or atypical Parkinsonism, especially with respect to their activities of daily living (ADL) over time SUMMARY OF BACKGROUND DATA.: Postural disorders associated with PD lead to spinal imbalance and deformity, resulting in significant disabilities. Clinical outcomes of extensive fusion surgeries in patients with PD over a medium-term follow-up period are currently unknown. Methods Patients with PD who underwent extensive fusion surgery more than 5 years prior were included. The patients' backgrounds, surgical and radiographic parameters, perioperative and mechanical complications, and indoor ADL over time were assessed. To assess the activities of severely disabled patients, indoor ADL was classified into four stages: independent; or cane, walker, and wheelchair use. Results Twenty-two patients (mean age, 70.6 yrs) were included. The mean blood loss, duration of surgery, and fusion levels were 2039 mL, 424 minutes, and 11.9 levels, respectively. Sagittal vertical axis improved from 220 mm preoperatively to 95 mm postoperatively. Perioperative complications were observed in 17 cases (77%). Before surgery, 1, 5, 12, and four cases were independent in ADL, T-cane, walker, and wheelchair use, respectively, which improved to seven, four, six, and four, respectively in 1 year. Revision surgeries were performed in eight patients (36%) within 3 years of surgery. In the 3 to 5 years after the surgery, the ADL of nine patients worsened due to deterioration of PD. Fifteen cases were followed up over 5 years, at which one, two, four, and seven cases were independent in ADL, cane, walker, and wheelchair use, respectively. Conclusion Surgical intervention in PD patients with spinal deformities leads to good short-term outcomes; however, the patients' conditions deteriorated because of complications within 3 years and worsening of PD over 3 years after the surgery. Level of evidence 4.

OBJECTIVETranscranial motor evoked potential (TcMEP) monitoring may be valuable for predicting postoperative neurological complications with a high sensitivity and specificity, but one of the most frequent problems is the high false-positive rate. The purpose of this study was to clarify the differences in the risk factors for false-positive TcMEP alerts seen when performing surgery in patients with pediatric scoliosis and adult spinal deformity and to identify a method to reduce the false-positive rate.METHODSThe authors retrospectively analyzed 393 patients (282 adult and 111 pediatric patients) who underwent TcMEP monitoring while under total intravenous anesthesia during spinal deformity surgery. They defined their cutoff (alert) point as a final TcMEP amplitude of ≤ 30% of the baseline amplitude. Patients with false-positive alerts were classified into one of two groups: a group with pediatric scoliosis and a group with adult spinal deformity.RESULTSThere were 14 cases of false-positive alerts (13%) during pediatric scoliosis surgery and 62 cases of false-positive alerts (22%) during adult spinal deformity surgery. Compared to the true-negative cases during adult spinal deformity surgery, the false-positive cases had a significantly longer duration of surgery and greater estimated blood loss (both p < 0.001). Compared to the true-negative cases during pediatric scoliosis surgery, the false-positive cases had received a significantly higher total fentanyl dose and a higher mean propofol dose (0.75 ± 0.32 mg vs 0.51 ± 0.18 mg [p = 0.014] and 5.6 ± 0.8 mg/kg/hr vs 5.0 ± 0.7 mg/kg/hr [p = 0.009], respectively). A multivariate logistic regression analysis revealed that the duration of surgery (1-hour difference: OR 1.701; 95% CI 1.364–2.120; p < 0.001) was independently associated with false-positive alerts during adult spinal deformity surgery. A multivariate logistic regression analysis revealed that the mean propofol dose (1-mg/kg/hr difference: OR 3.117; 95% CI 1.196–8.123; p = 0.020), the total fentanyl dose (0.05-mg difference; OR 1.270; 95% CI 1.078–1.497; p = 0.004), and the duration of surgery (1-hour difference: OR 2.685; 95% CI 1.131–6.377; p = 0.025) were independently associated with false-positive alerts during pediatric scoliosis surgery.CONCLUSIONSLonger duration of surgery and greater blood loss are more likely to result in false-positive alerts during adult spinal deformity surgery. In particular, anesthetic doses were associated with false-positive TcMEP alerts during pediatric scoliosis surgery. The authors believe that false-positive alerts during pediatric scoliosis surgery, in particular, are caused by “anesthetic fade.”

Degenerative lumbar scoliosis (DLS) is one of the most frequent spinal deformities of the aging spine. The purpose of our study was to clarify the independent predictors of pre-existing DLS progression and their influence on the health related quality of life (HRQOL).This study included 356 volunteers (127 men and 229 women; mean age, 72.2 years; follow-up period, 4 years) who underwent musculoskeletal screening. Standing whole-spine radiographic measurements included the Cobb angle of DLS and C7-center sacral vertical line (C7-CSVL; shift to the concave side of the DLS curve indicated a positive value). A baseline Cobb angle ≥10° indicated pre-existing DLS, and Cobb angle deterioration of ≥4° was considered DLS progression. For HRQOL assessment, the Oswestry Disability Index (ODI) was used. Pre-existing DLS cases were divided into progression and non-progression groups.Among 93 cases (26.1%) with pre-existing DLS at baseline, 23 cases (pre-existing DLS progression group) showed DLS progression. The mean C7-CSVLs were 10.5 and -3.1 mm in the pre-existing progression and non-progression groups, respectively (p 0.01). The optimal cutoff C7-CSVL length was 5 mm, with high sensitivity and specificity. Multivariate logistic regression analysis showed that a C7-CSVL ≥5 mm (odds ratio, 3.8; 95% CI: 1.42-10.34; p 0.01) was independently associated with pre-existing DLS progression. ODI scores deteriorated significantly more in the pre-existing progression group than the non-progression group (+9.8% versus +3.9%; p 0.05).Pre-existing DLS progression is associated with a shift to the concave side of C7-CSVL and influences HRQOL deterioration. It is important to assess coronal global alignment for prediction of a DLS progression.

A retrospective analysis of a prospectively collected consecutive case series of patients with adult spinal deformity who underwent 3-column osteotomy (3-CO) with pelvic fixation. The objectives were to verify the effect of additional rods and determine the optimal type of additional rod for preventing rod fracture (RF). RF is a frequent complication following 3-CO surgery in patients with adult spinal deformity. Two types of additional rod constructs were utilized to prevent RF. We evaluated data retrieved from a prospectively collected single-center database. Patients were classified into two groups depending on rod constructs: conventional 2-rod and 2-rod constructs with additional rods. The additional rod constructs were also stratified into two groups according to the location that they covered: only osteotomy site (short additional rod) or osteotomy site and lumbosacral junction (long additional rod). A total of 48 patients (average age 67.6 years; follow-up rate: 90.6%; 2-rod: 25 cases and additional rod: 23 cases) were included. No significant difference was observed in age, fusion level, operation time, blood loss, and rod composition. The incidence of RF in the additional rods (36%) was significantly lower than that in the 2-rod constructs (68%). Comparing the additional rod constructs, RF occurred in 7 cases (64%) in short additional rod and 2 cases (17%) in long additional rod. RF occurred at the level below the additional rod construct in 6 of 7 RF cases with short additional rod. Additional rods covering the osteotomy site and lumbosacral junction reduced the incidence of RF following 3-CO surgery with pelvic fixation in short term. 3.

Study design: Retrospective longitudinal cohort study. Objective: To investigate postoperative medical complications in patients with malnutrition after cervical posterior surgery. Methods: A total of 256 patients were participated and divided into PNI < 50 group (group L) or PNI ≥ 50 (group H). Patient data, preoperative laboratory data, surgical data, hospitalization data, JOA score, complication data were measured. Results: Group L and group H were 127 and 129 patients, each PNI was L: 44.8 ± 4.3, H: 54.6 ± 4.0, P < 0.01. There was significant difference in mean age (L: 72.2 years vs H: 64.8 years, P < 0.01), BMI (23.1 vs 24.7, P < 0.01), serum albumin (L: 3.9 ± 0.4 g/dl vs H: 4.4 ± 0.3 g/dl, P < 0.01), total lymphocyte count (L: 1.3 ± 0.5 103/µL vs H: 2.1 ± 0.7 103/μL, P < 0.01), hospital stay (L: 25.0 days vs H: 18.8 days, P < 0.05), discharge to home (87.5% vs 57.5%, P < 0.01), delirium (L: 15.9% vs H: 3.9%, P < 0.01), medical complications (L: 25.2% vs H: 7.0%, P < 0.01), pre- and post- operative JOA score (L: 11.3 ± 2.8 vs H: 12.4 ± 2.6, P < 0.01; L: 13.3 ± 3.0 vs H: 14.1 ± 2.4, P = 0.02). Multiple logistic regression analysis showed that significant risk factors for medical complications were PNIConclusion: Medical complications are significantly higher in patients with PNI < 50 and higher age. The results showed that PNI is a good indicator for perioperative medical complications in cervical posterior surgery. Improvement of preoperative nutritional status is important to avoid medical complications. Level of evidence: 3