Prevalence and distribution of Schmorl node and endplate signal change, and correlation with disc degeneration in a population-based cohort: the Wakayama Spine Study.

PURPOSE: Degenerative spinal conditions, including disc degeneration (DD), Schmorl nodes (SN), and endplate signal changes (ESC), are pervasive age-associated phenomena that critically affect spinal health. Despite their prevalence, a comprehensive exploration of their distribution and correlations is lacking. This study examined the prevalence, distribution, and correlation of DD, SN, and ESC across the entire spine in a population-based cohort. METHODS: The Wakayama Spine Study included 975 participants (324 men, mean age 67.2 years; 651 women, mean age 66.0 years). Magnetic resonance imaging (MRI) was used to evaluate the intervertebral space from C2/3 to L5/S1. DD was classified using Pfirrmann's system, ESC was identified by diffuse high-intensity signal changes on the endplates, and SN was defined as a herniation pit with a hypointense signal. We assessed the prevalence and distribution of SN, ESC, and DD across the entire spine. The correlations among these factors were examined. RESULTS: Prevalence of ≥ 1 SN over the entire spine was 71% in men and 77% in women, while prevalence of ≥ 1 ESC was 57.9% in men and 56.3% in women. The prevalence of ESC and SN in the thoracic region was the highest among the three regions in both sexes. Positive linear correlations were observed between the number of SN and DD (r = 0.41, p < 0.001) and the number of ESC and DD (r = 0.40, p < 0.001), but weak correlations were found between the number of SN and ESC (r = 0.29, p < 0.001). CONCLUSION: The prevalence and distribution of SN and ESC over the entire spine were observed, and correlations between SN, ESC, and DD were established. This population-based cohort study provides a comprehensive analysis of these factors.

A longitudinal population-based study identifies THBS2 as a susceptibility gene for intervertebral disc degeneration.

PURPOSE: Intervertebral disc degeneration (IDD) is a common degenerative disease associated with ageing. Additionally, IDD is recognized as one of the leading causes of low back pain and disability in the working-age population and is the first step in the process leading to degenerative spinal changes. However, the genetic factors and regulatory mechanisms of IDD remain unknown. Therefore, we selected eight single nucleotide polymorphisms of genes to reveal the progression of IDD in a 7-year longitudinal study of the general population in Japan. METHODS: IDD was evaluated in the Wakayama Spine Study (WSS), which is a population-based cohort study. Overall, 574 participants from the general population cohort who underwent whole spine magnetic resonance imaging and provided clinical information were included in this longitudinal survey. RESULTS: The progression of IDD was affected only by THBS2 at the lumbar region, T12-L1 (p = 0.0044) and L3-4 (p = 0.0045). The significant interaction between THBS2 and age with IDD negatively affected the thoracic spines and passively influenced both the thoracolumbar junction and thoracic spines. The higher progression per year of Pfirrmann's score was rapid in young people with age; however, this decelerated the IDD progression per year in different ages. CONCLUSION: Our longitudinal study found the genes associated with IDD progression and that genetic factors' impact on IDD differs depending on disc level and age.

Association between modic changes, disc degeneration, and pelvic incidence-lumbar lordosis mismatch in a large population based cohort: the Wakayama spine study.

PURPOSE: Sagittal plane alignment is crucial for treating spinal malalignment and low back pain. Pelvic incidence-lumbar lordosis (PI-LL) mismatch is commonly used to evaluate clinical outcomes in patients with sagittal malalignment. The association between PI-LL mismatch and changes surrounding the intervertebral disc is very important to understand the compensatory mechanisms involved. This study aimed to examine the association between PI-LL mismatch and magnetic resonance imaging (MRI) changes surrounding the intervertebral disc in a large population-based cohort. METHODS: We evaluated participants from the second Wakayama Spine Study, recruiting the general population aged 20 years or older, irrespective of sex, who were registered residents in one region in 2014. In total, 857 individuals underwent an MRI of the whole spine; however, 43 MRI results were not included due to incomplete or inadequate quality images. PI-LL mismatch was defined as > 11°. We compared the MRI changes, such as Modic change (MC), disc degeneration (DD), and high-intensity zones (HIZ), between PI-LL mismatch and non-PI-LL mismatch groups. Multivariate logistic regression analysis was conducted to determine the association between the MRI changes and PI-LL mismatch with adjustment for age, sex, and body mass index in the lumbar region and at each level. RESULTS: A total of 795 participants (243 men, 552 women, mean age 63.5 ± 13.1 years old) were evaluated; 181 were included in the PI-LL mismatch group. MC and DD in the lumbar region were significantly higher in the PI-LL mismatch group. MC in the lumbar region was significantly associated with PI-LL mismatch (odds ratio (OR); 1.81, 95% confidence interval (CI) 1.2-2.7). MC at each level was significantly associated with PI-LL mismatch (OR; 1.7-1.9, 95%CI 1.1-3.2), and DD at L1/2, L3/4, and L4/5 was associated with PI-LL mismatch (OR; 2.0- 2.4. 95%CI 1.2-3.9). CONCLUSION: MC and DD were significantly associated with PI-LL mismatch. Therefore, profiling MC may be helpful in improving the targeted treatment of LBP associated with the adult spinal deformity.

Spinopelvic fusion surgery from lower thoracic spine to pelvis increased hip joint moment-motion analysis.

PURPOSE: Spinal fusion surgery is often performed with pelvic fixation to prevent distal junctional kyphosis. The inclusion of spinopelvic fixation has been reported to induce progression of hip joint arthropathy in a radiographic follow-up study. However, its biomechanical mechanism has not yet been elucidated. This study aimed to compare the changes in hip joint moment before and after spinal fusion surgery. METHODS: This study was an observational study and included nine patients (eight women and one man) who were scheduled to undergo spinopelvic fusion surgery. We calculated the three-dimensional external joint moments of the hip during gait, standing, and climbing stairs before and 1 year after surgery. RESULTS: During gait, the maximum extension moment was 0.51 ± 0.29 and 0.63 ± 0.40 before and after spinopelvic fusion surgery (p = 0.011), and maximum abduction moment was 0.60 ± 0.33 and 0.83 ± 0.34 before and after surgery (p = 0.004), respectively. During standing, maximum extension moment was 0.76 ± 0.32 and 1.04 ± 0.21 before and after spinopelvic fusion surgery (p = 0.0026), and maximum abduction moment was 0.12 ± 0.20 and 0.36 ± 0.22 before and after surgery (p = 0.0005), respectively. During climbing stairs, maximum extension moment was - 0.31 ± 0.30 and - 0.48 ± 0.15 before and after spinopelvic fusion surgery (p = 0.040), and maximum abduction moment was 0.023 ± 0.18 and - 0.02 ± 0.13 before and after surgery (p = 0.038), respectively. CONCLUSION: This study revealed that hip joint flexion-extension and abduction-adduction moments increased after spinopelvic fixation surgery in the postures of standing, walking, and climbing stairs. The mechanism was considered to be adjacent joint disease after spinopelvic fusion surgery including sacroiliac joint fixation.

Ultrasonography is an effective tool for the evaluation of traumatic vertebral artery injuries distal to fourth cervical vertebra in the emergency room.

BACKGROUND: This study aimed to determine the feasibility of ultrasonography in the assessment of cervical vertebral artery (VA) injury as an alternative to computed tomography angiography (CTA) in the emergency room. METHODS: We analyzed 50 VAs from 25 consecutive patients with cervical spine injury that had been admitted to our emergency room. Ultrasonography and CTA were performed to assess the VA in patients with cervical spine injury. We examined the sensitivity and specificity of ultrasonography compared with CTA. RESULTS: Among these VAs, six were occluded on CTA. The agreement between ultrasonography and CTA was 98% (49/50) with 0.92 Cohen's Kappa index. The sensitivity, specificity, and positive and negative predictive values of ultrasonography were 100%, 97.7%, 85.7%, and 100%, respectively. In one case with hypoplastic VA, the detection of flow in the VA by ultrasonography differed from detection by CTA. Meanwhile, there were two cases in which VAs entered at C5 transverse foramen rather than at C6 level. However, ultrasonography could detect the blood flow in these VAs. CONCLUSIONS: Ultrasonography had a sensitivity of 100% compared with CTA in assessment of the VA. Ultrasonography can be used as an initial screening test for VA injury in the emergency room.

Clinical and radiographic characteristics of increased signal intensity of the spinal cord at the vertebral body level in patients with cervical myelopathy.

BACKGROUND: Increased signal intensity (ISI) is usually recognized at the disc level of the responsible lesion in the patients with cervical myelopathy. However, it is occasionally seen at the vertebral body level, below the level of compression. We aimed to investigate the clinical significance and the radiographic characteristics of ISI at the vertebral body level. METHODS: This retrospective study included 135 patients with cervical spondylotic myelopathy who underwent surgery and with local ISI. We measured the local and C2-7 angle at flexion, neutral, and extension. We also evaluated the local range of motion (ROM) and C2-7 ROM. The patients were classified into group D (ISI at disc level) and group B (ISI at vertebral body level). RESULTS: The prevalence was 80.7% (109/135) and 19.3% (26/135) for groups D and B, respectively. Local angle at flexion and neutral were more kyphotic in group B than in group D. The local ROM was larger in group B than in group D. Moreover, C2-7 angle at flexion, neutral and extension were more kyphotic in group B than in group D. Two years later, local angle at flexion, neutral, and extension were also kyphotic in group B than group D; however, local and C2-7 ROM was not significantly different between the two groups. There was no significant difference of clinical outcomes 2 years postoperatively between both groups. CONCLUSIONS: Group B was associated with the kyphotic alignment and local greater ROM, compared to group D. As the spinal cord is withdrawn in flexion, the ISI lesion at vertebral body might be displaced towards the disc level, which impacted by the anterior components of the vertebrae. ISI at the vertebral body level might be related to cord compression or stretching at flexion position. This should be different from the conventionally held pincer-mechanism concept.

A nationwide multicenter study of the cost effectiveness of five leading drugs for pharmacological management of cervicobrachial symptoms.

BACKGROUND: Cervicobrachial pain frequently affects the quality of life (QOL) of the general public and has a significant economic impact on the health care systems of various countries. There are a number of treatment options for this disease, including widely-used drug therapy, but the effectiveness of each option is indeterminate, and there have been no published cost-effectiveness analysis studies so far. This prospective observational study aimed to examine the cost-effectiveness of drug treatment for cervicobrachial symptoms. METHODS: A 6-month medication regimen for each of five frequently-prescribed drugs for cervicobrachial symptoms was administered to 322 patients at 24 centers in Japan. Outcome measures, including of the EuroQol Group 5D, Short Form-8, and Visual Analog Scale (VAS), were investigated at baseline and every month thereafter. Incremental cost-effectiveness ratios (ICERs) of the drug cost to quality-adjusted life years (QALYs) were calculated. A stratified analysis of patient characteristics was also performed to identify baseline factors potentially affecting cost-effectiveness. RESULTS: The ICER of entire drug treatment for cervicobrachial symptoms was 7,491,640 yen. Compared with the reference willingness-to-pay, the ICER was assumed to not be cost-effective. A certain number of QALYs were gained during the first 3 months after the treatment intervention, but almost no QALYs were gained during the following 3 months. Stratified analysis showed that cost-effectiveness was extremely low for patients with high baseline VAS and high QOL. CONCLUSIONS: The available medications for cervicobrachial symptoms did not have excellent cost-effectiveness. Although a certain number of QALYs were gained during the first 3 months after medication, no QALYs were gained in the latter half of the study period, suggesting that it is not advisable to continue the medication needlessly. LEVEL OF EVIDENCE: II, prospective cohort study.

Relationship between medial partite hallux sesamoid and hallux valgus in the general population.

BACKGROUND: An association between the medial partite hallux sesamoid (MPHS) and hallux valgus (HV) has been suggested; however, a causal relationship has not been confirmed. This study aimed to determine their causal relationship using a cross-sectional radiographic survey of a large-scale population cohort covering a wide age group. PATIENTS AND METHODS: The fifth survey of the Research on Osteoarthritis/Osteoporosis against Disability study involved 1997 participants aged 21-95 years who had undergone anteroposterior radiography of bilateral feet. The presence of MPHS, its morphology, and radiographic parameters related to the HV were assessed using radiographs. Changes in the prevalence of MPHS with age were assessed using trend tests. The relationship between the MPHS and HV was assessed based on sex and age. RESULTS: MPHS was found in 508 out of 3994 feet (12.7 %), with a significant difference in prevalence between men and women (10.0 % vs. 13.7 %, p < 0.001). Trend analysis demonstrated a significant decrease in MPHS occurrence with age in both sexes. HV angle was significantly higher in feet with MPHS than in those without (Men: 17.8 ± 7.0° vs. 14.0 ± 5.9°, p < 0.0001; Women: 19.6 ± 7.7° vs. 17.7 ± 7.9°, p < 0.0001). The prevalence of HV angle ≥ 20° was also significantly higher in feet with MPHS than in those without (Men: 33.3 % vs. 14.6 %, p < 0.0001; Women: 46.5 % vs. 34.6 %, p < 0.0001). This association between MPHS and HV was noticeable in younger adults and became less prominent with age. CONCLUSIONS: MPHS is associated with HV. The weakening of this relationship and the decreased prevalence of MPHS with age suggest that MPHS is not caused by HV, but is one of the causes of HV, especially in younger adults.

Epidemiology of locomotive syndrome using updated clinical decision limits: 6-year follow-ups of the ROAD study.

INTRODUCTION: Locomotive syndrome (LOCOMO) is defined by the Japanese Orthopaedic Association (JOA) as a condition requiring nursing care due to a decline in mobility resulting from musculoskeletal disorders. In 2020, the JOA announced the new definition of LOCOMO stage 3 and revision of clinical decision limits in stages of LOCOMO. However, there are few reports on the epidemiological indices of LOCOMO. This prospective cohort study aimed to investigate the prevalence, incidence, and association of poor prognosis with LOCOMO stages. MATERIALS AND METHODS: The third survey of the Research on Osteoarthritis/Osteoporosis Against Disability (ROAD) study was conducted during 2012-2013, examining a population-based cohort of 1575 participants (513 men and 1062 women, mean age 65.6 years). Three LOCOMO risk tests were performed, and patients were classified into LOCOMO stages 0, 1, 2, and 3. They were followed up for 6 years, and identical examination of LOCOMO was performed in 3- and 6-year follow-ups. Data on patients' prognoses, including disability and death, were collected. RESULTS: The prevalence of LOCOMO stages 1, 2, and 3 was 41.3, 14.9, and 11.6%, respectively. The incidence of LOCOMO stages 1, 2, and 3 were 83.7, 23.0, and 18.6 per 1000 person-years, respectively. Compared with LOCOMO stage 0, logistic regression analysis showed that LOCOMO stage 3 significantly increased the risk of disability and mortality. In addition, each value of LOCOMO risk tests for LOCOMO stage 3 increased the risk of poor prognosis. CONCLUSION: LOCOMO stage 3 is a sensitive indicator of future disability and mortality.

A novel technique using ultrasonography in upper airway management after anterior cervical decompression and fusion.

BACKGROUND: Airway complications are the most serious complications after anterior cervical decompression and fusion (ACDF) and can have devastating consequences if their detection and intervention are delayed. Plain radiography is useful for predicting the risk of dyspnea by permitting the comparison of the prevertebral soft tissue (PST) thickness before and after surgery. However, it entails frequent radiation exposure and is inconvenient. Therefore, we aimed to overcome these problems by using ultrasonography to evaluate the PST and upper airway after ACDF and investigate the compatibility between X-ray and ultrasonography for PST evaluation. METHODS: We included 11 radiculopathy/myelopathy patients who underwent ACDF involving C5/6, C6/7, or both segments. The condition of the PST and upper airway was evaluated over 14 days. The Bland-Altman method was used to evaluate the degree of agreement between the PST values obtained using radiography versus ultrasonography. The Pearson correlation coefficient was used to determine the relationship between the PST measurement methods. Single-level and double-level ACDF were performed in 8 and 3 cases, respectively. RESULTS: PST and upper airway thickness peaked on postoperative day 3, with no airway complications. The Bland-Altman bias was within the prespecified clinically nonsignificant range: 0.13 ± 0.36 mm (95% confidence interval 0.04-0.22 mm). Ultrasonography effectively captured post-ACDF changes in the PST and upper airway thickness and detected airway edema. CONCLUSIONS: Ultrasonography can help in the continuous assessment of the PST and the upper airway as it is simple and has no risk of radiation exposure risk. Therefore, ultrasonography is more clinically useful to evaluate the PST than radiography from the viewpoint of invasiveness and convenience.

S2 alar-iliac screw loosening as a preventive factor for hip joint osteoarthritis after adult spinal deformity surgery: a case-control study.

PURPOSE: This study aimed to evaluate the progression of hip pathology and risk factors after ASD surgery. METHODS: This case-control study enrolled 123 patients (246 hips); seven hips underwent hip arthroplasty were excluded. We measured the center-edge (CE) angle, joint space width (JSW), and Kellgren-Lawrence (KL) grade. We defined a CE angle˂25° as developmental dysplasia of the hip (DDH). We evaluated S2 alar-iliac (AI) screw loosening at final follow-up. RESULTS: The annual decrease in the JSW was 0.31 mm up to 1 year, and 0.13 mm after 1 year (p = 0.001). KL grade progression occurred in 24 hips (10.0%; group P), while no progression occurred in 215 (90.0%; group N) hips. Nonparametric analysis between groups P and N revealed that significant differences were observed in sex, DDH, KL grade, ratio of S2AI screw fixation at baseline, and ratio of S2AI screw loosening at final follow-up. Multiple logistic regression analysis revealed that DDH (p = 0.018, odds ratio (OR) = 3.0, 95%CI = 1.2-7.3), baseline KL grade (p < 0.0001, OR = 37.7, 95%CI = 7.0-203.2), and S2AI screw fixation (p = 0.035, OR = 3.4, 95%CI = 1.1-10.4) were significant factors. We performed sub-analysis to elucidate the relationship between screw loosening and hip osteoarthritis in 131 hips that underwent S2AI screw fixation. Non-loosening of the S2AI screw was a significant factor for KL grade progression (p < 0.0001, OR = 8.9, 95%CI = 3.0-26.4). CONCLUSION: This study identified the prevalence and risk factors for the progression of hip osteoarthritis after ASD surgery. Physicians need to pay attention to the hip joint pathology after ASD surgery.

Importance of physiological age in determining indications for adult spinal deformity surgery in patients over 75 years of age: a propensity score matching analysis.

PURPOSE: Physiologically, people age at different rates, which leads to a discrepancy between physiological and chronological age. Physiological age should be a priority when considering the indications for adult spinal deformity (ASD) surgery. The primary objective of this study was to determine the characteristics of the postoperative course, surgical outcomes, and complication rates to extend the healthy life expectancy of older ASD patients (≥ 75 years). The secondary objective was to clarify the importance of physiological age in the surgical treatment of older ASD patients, considering frailty. METHODS: A retrospective review of 109 consecutive patients aged ≥ 65 years with symptomatic ASD who underwent a corrective long fusion with lateral interbody fusion from the lower thoracic spine to the pelvis from 2015 to 2019 was conducted. Patients were classified into two groups according to age (group Y [65-74 years], group O [≥ 75 years]) and further divided into four groups according to the ASD-frailty index score (Y-F, Y-NF, O-F, and O-NF groups). To account for potential risk factors for perioperative course characteristics, complication rates, and surgical outcomes, patients from the database were subjected to propensity score matching based on sex, BMI, and preoperative sagittal spinal alignment (C7 sagittal vertical axis, pelvic incidence-lumbar lordosis, and pelvic tilt). Clinical outcomes were evaluated 2 years postoperatively, using three patient-reported outcome measures of health-related quality of life: the Oswestry Disability Index, Scoliosis Research Society questionnaire (SRS-22), and Short Form 36 (SF-36). Additionally, the postoperative time-to-first ambulation, as well as minor, major, and mechanical complications, were evaluated. RESULTS: In the comparison between Y and O groups, patients in group O were at a higher risk of minor complications (delirium and urinary tract infection). In contrast, other surgical outcomes of group O were comparable to those of group Y, except for SRS-22 (satisfaction) and time to ambulation after surgery, with better outcomes in Group O. Patients in the O-NF group had better postoperative outcomes (time to ambulation after surgery, SRS-22 (function, self-image, satisfaction), SF-36 [PCS]) than those in the Y-F group. CONCLUSIONS: Older age warrants monitoring of minor complications in the postoperative management of patients. However, the outcomes of ASD surgery depended more on frailty than on chronological age. Older ASD patients without frailty might tolerate corrective surgery and have satisfactory outcomes when minimally invasive techniques are used. Physiological age is more important than chronological age when determining the indications for surgery in older patients with ASD.

Association between serum insulin-like growth factor 1 and locomotive syndrome in community-dwelling older people.

BACKGROUND: Locomotive syndrome (LS) is a condition in which mobility decreases, and it is known as a risk factor for elderly persons needing care in connection with sarcopenia and frailty. Prevention or delay of the onset of these diseases is important for preventing the need for care, and identification of biomarkers as indicators for appropriate intervention is useful. The present study aimed to clarify whether the serum insulin-like growth factor 1 (IGF-1) level, which has been reported to be related to sarcopenia and frailty, is related to LS. METHODS: The study participants were 133 elderly people living in a rural area in Japan. LS was assessed using Locomo-25, which is a self-administered questionnaire, and LS was defined as a Locomo-25 score ≥ 7 points. Serum IGF-1 and albumin levels were measured. A self-completed medical history questionnaire was used. RESULTS: On multiple linear regression analysis, age, IGF-1, osteoporosis, and osteoarthritis were significantly associated with the Locomo-25 score. The receiver-operating characteristic curve analysis of the IGF-1 level showed a threshold value of 82.0 ng/mL for discriminating non-LS and LS. The logistic regression analysis adjusted for osteoporosis, osteoarthritis, and the propensity score estimated from sex, age, and BMI showed that the odds ratio (OR) of the IGF-1 level for LS was 1.019 (95% confidence interval [CI], 1.002-1.039; p = 0.027), and the OR of IGF-1 ≤ 82 ng/mL for LS was 2.275 (95% CI 0.993-5.324; p = 0.052). CONCLUSIONS: The present findings suggest that osteoporosis and osteoarthritis were associated with early LS, and a decrease of the serum IGF-1 level was a significant independent factor for early LS.

The discrepancy between radiographically-assessed and self-recognized hallux valgus in a large population-based cohort.

BACKGROUND: There has been a paucity of literature revealing the discrepancy between self-recognition about hallux valgus (HV) and radiographically-evaluated foot configuration. Knowing this discrepancy will help to make a comparative review of the findings of previous literatures about epidemiological studies about the prevalence of HV. QUESTIONS/PURPOSES: (1) Is there a discrepancy between radiographically-assessed and self-recognized HV in the general population? (2) What factors affect the self-recognition of HV in the general population? METHODS: The fifth survey of the Research on Osteoarthritis/Osteoporosis against Disability study involved 1996 participants who had undergone anterior-posterior radiography of bilateral feet and answered a simple dichotomous questionnaire on self-recognition of HV. Measurements of the HV angle (HVA), interphalangeal angle of the hallux (IPA), and intermetatarsal angle between 1st and 2nd metatarsals (IMA) were performed using radiographs. Radiographic diagnosis of HV was done using the definition of hallux valgus angle of 20° or more. After univariate comparison of the participant backgrounds and radiographic measurements between participants with or without self-recognition of HV, multivariable logistic regression analysis was conducted in order to reveal independent factors affecting self-recognition. RESULTS: Significant difference was found between the prevalence of radiographically-assessed and self-recognized HV (29.8% vs. 16.5%, p <  0.0001). The prevalence of self-recognized HV increased with the progression of HV severity from a single-digit percentage (normal grade, HVA < 20°) up to 100% (severe grade, HVA ≥ 40°). A multivariable logistic regression analysis demonstrated that HVA, IMA, and female sex were independent positive factors for self-recognition of HV (HVA [per 1° increase]: OR, 1.18; 95% CI, 1.15-1.20; p <  0.0001; IMA [per 1° increase]: OR, 1.15; 95% CI, 1.09-1.20; p <  0.0001; and female sex [vs. male sex]: OR, 3.47; 95% CI, 2.35-5.18; p <  0.0001). CONCLUSIONS: There was a significant discrepancy between radiographically-assessed and self-recognized HV which narrowed with the progressing severity of HV. HVA, IMA, and female sex were independent positive factors for self-recognition of HV. Attention needs to be paid to potentially lowered prevalence of HV in epidemiological studies using self-reporting based on self-recognition.

Lateral interbody release for fused vertebrae via transpsoas approach in adult spinal deformity surgery: a preliminary report of radiographic and clinical outcomes.

BACKGROUND: Lateral interbody release (LIR) via a transpsoas lateral approach is a surgical strategy to address degenerative lumbar scoliosis (DLS) patients with anterior autofusion of vertebral segments. This study aimed to characterize the clinical and radiographic outcomes of this lumbar reconstruction strategy using LIR to achieve anterior column correction. METHODS: Data for 21 fused vertebrae in 17 consecutive patients who underwent LIR between January 2014 and March 2020 were reviewed. Demographic and intraoperative data were recorded. Radiographic parameters were assessed preoperatively and at final follow-up, including segmental lordotic angle (SLA), segmental coronal angle (SCA), bone union rate, pelvic incidence (PI), lumbar lordosis (LL), pelvic tilt, sacral slope, PI-LL mismatch, sagittal vertical axis, Cobb angle, and deviation of the C7 plumb line from the central sacral vertical line. Clinical outcomes were evaluated using Oswestry Disability Index (ODI), visual analog scale (VAS) scores for low back and leg pain, and the short form 36 health survey questionnaire (SF-36) postoperatively and at final follow-up. Complications were also assessed. RESULTS: Mean patient age was 70.3 ± 4.8 years and all patients were female. Average follow-up period was 28.4 ± 15.3 months. Average procedural time to perform LIR was 21.3 ± 9.7 min and was not significantly different from traditional lateral interbody fusion at other levels. Blood loss per single segment during LIR was 38.7 ± 53.2 mL. Fusion rate was 100.0% in this cohort. SLA improved significantly from - 7.6 ± 9.2 degrees preoperatively to 7.0 ± 8.8 degrees at final observation and SCA improved significantly from 19.1 ± 7.8 degrees preoperatively to 8.7 ± 5.9 degrees at final observation (P < 0.0001, and < 0.0001, respectively). All spinopelvic and coronal parameters, as well as ODI and VAS, improved significantly. Incidence of peri- and postoperative complications such as iliopsoas muscle weakness and leg numbness in patients who underwent LIR was as much as XLIF. Incidence of postoperative mechanical failure following LIR was also similar to XLIF. Reoperation rate was 11.8%. However, there were no reoperations associated with LIR segments. CONCLUSIONS: The LIR technique for anterior column realignment of fused vertebrae in the context of severe ASD may be an option of a safe and effective surgical strategy.

Adjacent segment disease on hip joint as a complication of spinal fusion surgery including sacroiliac joint fixation.

PURPOSE: Recently, the number of adult spinal deformity surgeries including sacroiliac joint fixation (SIJF) by using an S2 alar iliac screw or iliac screw has increased to avoid the distal junctional failure. However, we occasionally experienced patients who suffered from hip pain after a long instrumented spinal fusion. We hypothesized that long spinal fusion surgery including SIJF influenced the hip joint as an adjacent joint. The aim of this paper was to evaluate the association between spinal deformity surgery including SIJF and radiographic progression of hip osteoarthritis (OA). METHODS: This study was retrospective cohort study. In total, 118 patients who underwent spinal fusion surgery at single center from January 2013 to August 2018 were included. We measured joint space width (JSW) at central space of the hip joint. We defined reduction of more than 0.5 mm/year in JSW as hip OA progression. The patients were divided into two groups depending on either a progression of hip osteoarthritis (Group P), or no progression (Group N). RESULTS: The number of patients in Group P and Group N was 47 and 71, respectively. Factor that was statistically significant for hip OA was SIJF (p = 0.0065, odds ratio = 7.1, 95% confidence interval = 1.6-31.6). There were no other significant differences by the multiple logistic regression analysis. CONCLUSION: This study identified spinal fixation surgery that includes SIJF as a predictor for radiographic progression of hip OA over 12 months. We should pay attention to hip joint lesions after adult spinal deformity surgery, including SIJF.

Association between types of Modic changes in the lumbar region and low back pain in a large cohort: the Wakayama spine study.

PURPOSE: The clinical significance of Modic changes in low back pain (LBP) is yet to be clarified. Thus, this study aimed to examine the association between Modic changes and LBP after adjustment for confounding factors. METHODS: We evaluated participants in the second Wakayama Spine Study. The degree of endplate changes as measured using magnetic resonance imaging was classified based on the Modic classification system. The prevalence of the types of Modic change in the lumbar region and at each level was assessed. Multivariate logistic regression analysis was conducted to determine the association between the types of Modic changes and LBP with adjustment for age, sex, body mass index, disc degeneration score, and disc displacement score. The LBP intensity was also compared according to the Visual Analogue Scale (VAS) score among the three types of Modic change. RESULTS: Overall, 814 subjects were evaluated. Type II Modic changes were the most prevalent (41.9%). Only type I Modic changes were significantly associated with LBP (odds ratio): 1.84, 95% confidence interval [CI]: 1.1-2.9). The LBP VAS score was significantly higher in subjects with type I Modic change than that in those with no Modic change (23.9 ± 26.3 vs. 9.9 ± 19.4, p < 0.05). CONCLUSION: Type I Modic changes in the lumbar region are significantly associated with LBP. Profiling Modic changes may be helpful to improve targeted treatment of LBP.

Lateral lumbar interbody fusion after reduction using the percutaneous pedicle screw system in the lateral position for Meyerding grade II spondylolisthesis: a preliminary report of a new lumbar reconstruction strategy.

BACKGROUND: Utilization of a cage with a large footprint in lateral lumbar interbody fusion (LLIF) for the treatment of spondylolisthesis leads to a high fusion rate and neurological improvement owing to the indirect decompression effect and excellent alignment correction. However, if an interbody space is too narrow for insertion of an LLIF cage for cases of spondylolisthesis of Meyerding grade II or higher, LLIF cannot be used. Therefore, we developed a novel strategy, LLIF after reduction by the percutaneous pedicle screw (PPS) insertion system in the lateral position (LIFARL), for surgeons to perform accurate and safe LLIF with PPS in patients with such pathology. This study aimed to introduce the new surgical strategy and to present preliminary clinical and radiological results of patients with spondylolisthesis of Meyerding grade II. METHODS: Six consecutive patients (four men and two women; mean age, 72.7 years-old; mean follow-up period, 15.3 months) with L4 spondylolisthesis of Meyerding grade II were included. Regarding the surgical procedure, first, PPSs were inserted into the L4 and L5 vertebrae fluoroscopically, and both rods were placed in the lateral position. The L5 set screws were fixed tightly, and the L4 side of the rod was floated. Second, the L4 vertebra was reduced by fastening the L4 set screws so that they expanded the anteroposterior width of the interbody space. At that time, the L4 set screws were not fully tightened to the rods to prevent the endplate injury. Finally, the LLIF procedure was started. After inserting the cage, a compression force was added to the PPSs, and the L4 set screws were completely fastened. RESULTS: The mean operative time was 183 min, and the mean blood loss was 90.8 mL. All cages were positioned properly. Visual analog scale score and Oswestry disability index improved postoperatively. Bone union was observed using computed tomography 12 months after surgery. CONCLUSION: For cases with difficulty in LLIF cage insertion for Meyerding grade II spondylolisthesis due to the narrow anteroposterior width of interbody space, LIFARL is an option to achieve LLIF combined with posterior PPS accurately and safely. TRIAL REGISTRATION: UMIN-Clinical Trials Registry, UMIN000040268, Registered 29 April 2020, https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000045938.

Improving effect of microendoscopic decompression surgery on low back pain in patients with lumbar spinal stenosis and predictive factors of postoperative residual low back pain: a single-center retrospective study.

BACKGROUND: Although there are reports on the effectiveness of microendoscopic laminotomy using a spinal endoscope as decompression surgery for lumbar spinal stenosis, predicting the improvement of low back pain (LBP) still poses a challenge, and no clear index has been established. This study aimed to investigate whether microendoscopic laminotomy for lumbar spinal stenosis improves low back pain and determine the preoperative predictors of residual LBP. METHODS: In this single-center retrospective study, we examined 202 consecutive patients who underwent microendoscopic laminotomy for lumbar spinal stenosis with a preoperative visual analog scale (VAS) score for LBP of ≥40 mm. The lumbar spine Japanese Orthopaedic Association (JOA), and VAS scores for LBP, leg pain (LP), and leg numbness (LN) were examined before and at 1 year after surgery. Patients with a 1-year postoperative LBP-VAS of ≥25 mm composed the residual LBP group. The preoperative predictive factors associated with postoperative residual LBP were analyzed. RESULTS: JOA scores improved from 14.1 preoperatively to 20.2 postoperatively (p < 0.001), LBP-VAS improved from 66.7 to 29.7 mm (p < 0.001), LP-VAS improved from 63.8 to 31.2 mm (p < 0.001), and LN-VAS improved from 63.3 to 34.2 mm (p < 0.001). Ninety-eight patients (48.5%) had a postoperative LBP-VAS of ≥25 mm. Multiple logistic regression analysis revealed that Modic type 1 change (odds ratio [OR], 5.61; 95% confidence interval [CI], 1.68-18.68; p = 0.005), preoperative VAS for LBP ≥ 70 mm (OR, 2.19; 95% CI, 1.17-4.08; p = 0.014), and female sex (OR, 1.98; 95% CI, 1.09-3.89; p = 0.047) were preoperative predictors of residual LBP. CONCLUSION: Microendoscopic decompression surgery had an ameliorating effect on LBP in lumbar spinal stenosis. Modic type 1 change, preoperative VAS for LBP, and female sex were predictors of postoperative residual LBP, which may be a useful index for surgical procedure selection.

Could automated machine-learned MRI grading aid epidemiological studies of lumbar spinal stenosis? Validation within the Wakayama spine study.

BACKGROUND: MRI scanning has revolutionized the clinical diagnosis of lumbar spinal stenosis (LSS). However, there is currently no consensus as to how best to classify MRI findings which has hampered the development of robust longitudinal epidemiological studies of the condition. We developed and tested an automated system for grading lumbar spine MRI scans for central LSS for use in epidemiological research. METHODS: Using MRI scans from the large population-based cohort study (the Wakayama Spine Study), all graded by a spinal surgeon, we trained an automated system to grade central LSS in four gradings of the bone and soft tissue margins: none, mild, moderate, severe. Subsequently, we tested the automated grading against the independent readings of our observer in a test set to investigate reliability and agreement. RESULTS: Complete axial views were available for 4855 lumbar intervertebral levels from 971 participants. The machine used 4365 axial views to learn (training set) and graded the remaining 490 axial views (testing set). The agreement rate for gradings was 65.7% (322/490) and the reliability (Lin's correlation coefficient) was 0.73. In 2.2% of scans (11/490) there was a difference in classification of 2 and in only 0.2% (1/490) was there a difference of 3. When classified into 2 groups as 'severe' vs 'no/mild/moderate'. The agreement rate was 94.1% (461/490) with a kappa of 0.75. CONCLUSIONS: This study showed that an automated system can "learn" to grade central LSS with excellent performance against the reference standard. Thus SpineNet offers potential to grade LSS in large-scale epidemiological studies involving a high volume of MRI spine data with a high level of consistency and objectivity.