Spine Surgery and Related Research
Online ISSN : 2432-261X
ISSN-L : 2432-261X
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Displaying 1-50 of 50 articles from this issue
  • Arash Sarveazad, Amirmohammad Toloui, Aida Moarrefzadeh, Hanieh Ghasem ...
    Article ID: 2022-0004
    Published: 2022
    Advance online publication: June 13, 2022
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    Supplementary material

    Background: Considering the limitations of cell therapy, in case of adequate treatment efficacy, conditioned media (CM) may be a desirable alternative to cell therapy. Hence, the present systematic review and meta-analysis aims to evaluate the efficacy of mesenchymal stem cell-derived conditioned media (MSC-CM) in movement resolution following spinal cord injury (SCI) in animal models.

    Methods: A comprehensive search in the databases of Medline, Scopus, Web of Science, and Embase was completed until the end of March 2021. Animal studies that evaluate the efficacy of MSC-CM on movement resolution following SCI were defined as the inclusion criteria. Lack of an SCI-untreated group, CM derived from a source other than MSC, not assessing motor function, failure to report CM administered dose, a follow-up period of less than 4 weeks, duplicates, and review articles were counted as the exclusion criteria. Final results are presented as overall standardized mean difference (SMD) with a 95% confidence interval (CI).

    Results: From the 361 nonduplicate articles, data from 11 articles were entered into the present meta-analysis. The analyses showed that MSC-CM administration in SCI animal models promotes motor recovery (SMD = 2.32; 95% CI: 1.55, 3.09; p < 0.0001). Subgroup analysis was performed because of the noticeable heterogeneity between the studies (I2 = 80.97%, p < 0.0001), depicting that antibiotic administration, delivery amount, delivery type, and follow-up time were the possible sources of heterogeneity. Moreover, multiple meta-regression demonstrated that in cases of delivery amount of more than 120 μL, the efficacy of MSC-CM administration in motor recovery is more than that of delivery amount of less than 120 μL (regression coefficient = 3.30; 95% CI: 0.72, 5.89; p = 0.019).

    Conclusion: Based on the results of the present study, it can be concluded that MSC-CM administration in SCI models improves motor recovery. The efficacy of this treatment strategy significantly increases at doses higher than 120 μL.

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  • Akihito Kawai, Sachiko Kawasaki, Tomoko Nishimura, Hideki Shigematsu, ...
    Article ID: 2022-0009
    Published: 2022
    Advance online publication: June 13, 2022
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  • Hirotsugu Omi, Toru Yokoyama, Takuya Naraoka, Sanae Omi, Kazunari Take ...
    Article ID: 2022-0014
    Published: 2022
    Advance online publication: June 13, 2022
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    Introduction: Cervical spine surgery reduces falls and subsequent femoral fractures. Nonetheless, current evidence on the prevalence of cervical cord compression (CCC) and increased signal intensity (ISI) in patients with femoral fractures is limited. We aimed to determine the prevalence of CCC and ISI and characterize the physical status and imaging findings using cervical spine magnetic resonance imaging (MRI) and brain computed tomography (CT) in patients with femoral fractures.

    Methods: This study included 173 patients (140 women, 33 men) with femoral fractures caused by falling, who underwent both cervical spine MRI and brain CT. CCC cases classified as grade 2 (compression of less than one-third of the spinal cord) or higher were investigated. The ISI of the severely affected intervertebral disc level was evaluated using T2-weighted MRI. Hand grip strength and myelopathic signs were also evaluated. Data analysis was performed using the χ2 test, Fisher's exact test, and Student's t-test.

    Results: Among the 173 patients, 83 (48.0%) had CCC, 29 (16.8%) had ISI, and 68 (39.3%) had abnormal brain CT findings. There was no ISI in patients in the non-CCC group. The patients' average age in the CCC group was significantly higher than that in the non-CCC group. There was no significant difference in the proportion of myelopathic sign and abnormal brain CT findings between the CCC and non-CCC groups or between the ISI and non-ISI groups. Bilateral hand grip strength was significantly negatively correlated with the stenosis rate (right, p = 0.047; left, p = 0.0018).

    Conclusions: In conclusion, our study showed that patients with femoral fractures had a high frequency of cervical canal stenosis and intracranial lesions using cervical spine MRI and brain CT.

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  • Erik B. Gerlach, Felipe Ituarte, Mark A. Plantz, Peter R. Swiatek, Nic ...
    Article ID: 2022-0030
    Published: 2022
    Advance online publication: June 13, 2022
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    Introduction: The management of degenerative spine pathology continues to be a significant source of costs to the US healthcare system. Besides surgery, utilization of healthcare resources after spine surgery drives costs. The responsibility of managing costs is gradually shifting to patients and providers. Patient-centered predictors of healthcare utilization after elective spine surgery may identify targets for cost reduction and value creation. Therefore, our study aims to quantify patterns of healthcare utilization and identify risk factors that predict high healthcare utilization after elective spine surgery.

    Methods: A total of 623 patients who underwent elective spine surgery at a tertiary academic medical center by one of three fellowship-trained orthopedic spine surgeons between 2013 and 2018 were identified in this retrospective cohort study. Healthcare utilization was quantified including advanced spine imaging, emergency and urgent care visits, hospital readmission, reoperation, PT/OT referrals, opioid prescriptions, epidural steroid injections, and pain management referrals. Patient variables, namely, the Charlson comorbidity index (CCI) and the American Society of Anesthesiologists (ASA) classification system, were assessed as potential predictors for healthcare utilization.

    Results: Among all patients, a wide range of health utilization was identified. Age, body mass index, Charlson Comorbidity Index, and American Society of Anesthesiology class were identified as positive predictors of postoperative healthcare utilization including emergency department visits, spine imaging studies, opioid and nerve blocker prescriptions, inpatient rehabilitation, any referrals, and pain management referrals.

    Conclusions: Markers of patient health—such as CCI and ASA class—may be used to predict healthcare utilization following elective spine surgery. Identifying at-risk patients and addressing these challenges prior to surgery is an important step to deliver efficient postoperative care.

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  • Takeru Tsujimoto, Masahiro Kanayama, Kota Suda, Fumihiro Oha, Miki Kom ...
    Article ID: 2022-0036
    Published: 2022
    Advance online publication: June 13, 2022
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    Introduction. Despite perioperative risks in nonagenarian patients who undergo open spine surgery for degeneration disorder or spinal trauma being of great interest, the prevalence of complications in this group remains unclear. This study aims to examine the perioperative complications of open spine surgery in the elderly over 90 years of age.

    Methods. Preoperative and intraoperative characteristics including the American Society of Anesthesiologists Physical Status (ASA-PS) class, type of surgery, and complications within 30 postoperative days were retrospectively collected from the medical records of nonagenarians who underwent open spine surgery between April 2004 and July 2019 at our spine centers.

    Results. A total of 48 patients met the inclusion criteria of this study. All belong to ASA-PS class 2 (69%) or 3. Preoperative American Spinal Injury Association Impairment Scale grades in trauma group were grade A in 4 cases, B in 1 case, C in 5 cases, D in 11 cases, and E in 1 case.Major complications (deep surgical site infection, cardiac event, respiratory disorder, gastrointestinal hemorrhage, and renal failure) occurred in 13 cases, and the rate of overall perioperative complications was 45.8%. One patient who underwent cervical stabilization for cervical fracture dislocation died at postoperative 13 days due to respiratory disorder. The rates of major complications and overall perioperative complications were 3.6% and 14.3% in the degenerative group and 45.5% and 81.8% in the trauma group, respectively. Especially in the trauma group, respiratory disorder occurred in 7 cases, delirium in 11 cases, and urinary tract infection in 5 cases.

    Conclusions. Although the perioperative complication rate reached 81.8% in spinal trauma cases, the complication rate in degenerative disorders was relatively low as 14.3%. Open spine surgery for degenerative disorders can be relatively safe even in nonagenarians, whereas the risks of perioperative complications, including respiratory disorder and delirium, were high in spinal trauma cases.

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  • Bungo Otsuki, Shunsuke Fujibayashi, Takayoshi Shimizu, Koichi Murata, ...
    Article ID: 2022-0052
    Published: 2022
    Advance online publication: June 13, 2022
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    Introduction Although previous studies reported the clinical significance of drains in lumbar surgery, their role in and effects on the clinical outcomes of cervical spine surgery remain unclear. The present study compared the clinical outcomes of cervical laminoplasty (CLP) using a closed suction drain (CSD) and closed nonsuction drain (CNSD).

    Methods Prospectively recorded surgical data on consecutive patients who underwent CLP at a single institution between 2014 and 2020 and were followed up for at least 1 year were examined. CSD was used prior to January 2018, and CNSD has since been employed. One hundred patients who underwent surgery before and after the change in drain type (the CSD and CNSD groups, respectively) were selected for analysis. Primary outcome measures were the drainage amount, blood count, and fluid collection at the surgical site defined by magnetic resonance images. The Japanese Orthopaedic Association (JOA) score for the cervical spine was also evaluated as a functional outcome.

    Results No significant differences were observed in demographic, baseline clinical, or surgical data between the CSD and CNSD groups. The drainage amount was significantly greater in the CSD group than in the CNSD group (224 vs. 143 mL, P <0.001). Hemoglobin and hematocrit levels were significantly decreased in the CSD group than in the CNSD group. Medium or large fluid collection was significantly more common in the CNSD group than in the CSD group. No significant differences were observed in the number of surgical site infections, the formation of symptomatic hematoma, or JOA scores between the two groups.

    Conclusions

    The use of CNSD in CLP decreased the drainage amount and maintained the hemoglobin level compared with that of CSD. Although no patients developed symptomatic hematoma, the amount of epidural fluid collected was larger in the CNSD group than in the CSD group.

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  • Daisuke Inoue, Hideki Shigematsu, Hiroaki Matsumori, Yurito Ueda, Yasu ...
    Article ID: 2022-0055
    Published: 2022
    Advance online publication: June 13, 2022
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    Introduction: Pedicle screws (PSs) or lateral mass screws (LMSs) are used in posterior cervical spine fixation. The former are more firmly fixed but are associated with the risk of neurovascular injury and should be inserted using intraoperative imaging or navigation, which may prolong the surgical duration and is not feasible in all hospitals. This prospective clinical study aimed to evaluate the outcomes of LMS insertions without fluoroscopic guidance and screw loosening rates at 6 months postoperatively using computed tomography (CT).

    Methods: We examined 38 patients who underwent posterior cervical spine fusion using 206 LMSs in the C3–C6 range between January 2018 and July 2021. The direction of screw insertion followed the Magerl method, and we inserted screws as bicortically as possible without intraoperative imaging. The screw position was examined using CT at 1 week postoperatively. Screw insertion angles, bicortical insertion rate, facet violation, and neurovascular injury were evaluated. Screw loosening with unicortical and bicortical screws (US and BS, respectively) was investigated using CT at 6 months postoperatively.

    Results: The average LMS length was 14.1 mm. The average axial and sagittal angles were 33.9° and 29.2°, respectively. Among the 206 LMSs inserted, 167 were BS; of these, 94.6% had screw length protrusion of 0–2 mm. Facet violation was observed in 3.4% of all screws but without neurovascular injury. Six months postoperatively, loosening of 25 screws (12.1%) occurred, including 17 (18.3%) USs and 8 (8.39%) BSs. The screw loosening rate was significantly higher in US than for BS (43.6% [17/39] vs. 4.8% [8/167], P < 0.01).

    Conclusions: Over 80% of LMSs were inserted bicortically without intraoperative imaging. By devising the screw length selection process, we inserted for screw loosening was more common in US and more likely at the fixed end.

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  • Kazuya Kitamura, Kentaro Fukuda, Yuichiro Takahashi, Takeshi Fujii, Ma ...
    Article ID: 2022-0005
    Published: 2022
    Advance online publication: May 10, 2022
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    Introduction: The efficacy of minimally invasive surgeries for thoracolumbar flexion-distraction injuries (FDIs) has been reported, but those surgeries were monosegmental fusion surgeries of two adjacent vertebrae with bone grafts or temporary fixations using percutaneous pedicle screws (PPSs) that were at least bisegmental. Our idea was to fuse the fracture itself, not to fuse the fractured vertebra with an adjacent vertebra or to stabilize the fractured vertebra by bridging rostrally/caudally adjacent intact vertebrae, specifically when the displacement is minimal. This study aimed to present the surgical techniques of reduction and temporary monosegmental fixation of neurologically intact thoracolumbar bony FDIs using multiaxial PPSs, which can minimize the surgical invasiveness and preserve all motion segments, as well as report three cases treated with this procedure.

    Technical Note: When the fracture extended from the vertebral body to the spinous process at the same level, screws were placed into the fractured vertebra rostrally to the fracture along the rostral endplate, and the caudally adjacent vertebra was instrumented beyond the fracture line. When the fracture extended from the vertebral body to the spinous process of the rostrally adjacent vertebra, screws were placed into the fractured vertebra caudally to the fracture line, and the rostrally adjacent vertebra was instrumented. The kyphotic deformity was reduced through ligamentotaxis by using MPPSs in the rostral vertebra as rigid joysticks to apply direct buttress leverage to the rostral endplate. Intraoperative blood loss was minimal. The correction of kyphotic deformity and its durability were acceptable, and the segmental range of motion of the two affected vertebrae from flexion to extension was maintained after implant removal.

    Conclusions: This surgery can act as the least-invasive option for the management of thoracolumbar bony FDIs to allow early ambulation without external bracing and to preserve all the motion segments.

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  • Kenichiro Sakai, Toshitaka Yoshii, Yoshiyasu Arai, Ichiro Torigoe, Hir ...
    Article ID: 2022-0040
    Published: 2022
    Advance online publication: May 10, 2022
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    Introduction: In Japan, cervical total disc replacement (TDR) was approved in 2017. However, because of its short history, no comparative study between cervical TDR and anterior cervical discectomy with fusion (ACDF) has been conducted in the country. Therefore, we examined and compared the surgical outcomes of TDR and ACDF for one-level cervical degenerative diseases.

    Methods: In total, 50 patients who had received anterior surgeries for one-level cervical degenerative diseases were investigated. Among them, 25 underwent TDR (Prestige LP; Medtronic), whereas the other 25 patients underwent ACDF. ACDF samples were selected from cases conducted before the approval of TDR (−2017.9) and were retrospectively judged to be indicated for TDR. Before and at 1 year after surgery, clinical and radiological outcomes were evaluated.

    Results: No significant differences in terms of patient demographics between the two groups were observed. A longer operative time was observed in the TDR group than in the ACDF group. Postoperatively, no differences in the Japanese Orthopaedic Association score for cervical myelopathy (C-JOA) score, neck pain visual analog scale, C2-7 angle, and C2-7 range of motion (ROM) were determined. TDR tended to show better neck disability index (NDI) scores postoperatively when compared with ACDF. The local angle at operative level was larger in ACDF. In TDR, the local ROMs were maintained postoperatively; however, in ACDF, the local ROM at the operative level was decreased, and the local ROMs at adjacent levels were increased postoperatively. In the TDR group, although heterotopic ossification was observed in 11 patients (44.0%), and anterior bone loss was identified in 14 patients (56.0%), these issues did not affect surgical outcomes.

    Conclusions: Conclusively, no differences in terms of C-JOA score and neck pain between patients treated through TDR and ACDF were observed. However, a trend of better NDI scores was identified with TDR. While TDR maintained postoperative ROMs, ACDF showed an increase in the local ROMs at adjacent levels.

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  • Kazuhiro Hasegawa, Jean Felix Dubousset
    Article ID: 2022-0038
    Published: 2022
    Advance online publication: April 20, 2022
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    A bipedal erect posture with a horizontal gaze is a distinctly human characteristic. The standing mechanism was described by Jean Felix Dubousset in the early 1970s as the "cone of economy," in which the axial skeleton is aligned in balance with the feet, lower limbs, and pelvis (pelvic vertebra) to the spinal segments, ending with the cranium (cephalic vertebra). All the components act in concert, allowing for adaptive motion in all directions on the horizontal plane. In a normal subject, the body maintains balance within a small "cone" using minimal muscle activity, and in a subject with pathologic lesions of the locomotor system, maintaining a standing posture requires a larger "cone" and greater muscle activity. Evidence from recent studies using the EOS imaging system, force plate measurements, surface electromyography, and full-body reflective markers with surface electromyography have gradually consolidated the "cone of economy" concept, a fundamental hypothetical theory of human locomotion.

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  • James M. Mok, Jason A. Strelzow, Van L. Vallina, Lukas P. Zebala
    Article ID: 2021-0097
    Published: 2022
    Advance online publication: April 12, 2022
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    Introduction

    Sacroplasty is a minimally invasive treatment option for severe pain due to sacral insufficiency fracture. Cement leakage is a known risk of sacroplasty. Despite the elevated risk to the L5 nerve root and lumbosacral trunk from cement leakage anterior to the sacral ala, there are no reports regarding surgical management of this complication.

    Technical Note

    We describe an anterior retroperitoneal transpsoas approach to the sacral ala to remove cement leakage causing acute L5 radiculopathy in a 57-year-old gentleman who had undergone sacroplasty for sacral insufficiency fracture (Denis zone 1). The approach provides rapid and excellent visualization of the sacral ala without manipulation of the iliac vessels.

    Conclusions

    We recommend that surgery be considered in a timely fashion, to utilize neuromonitoring, and that surgeons be aware of the considerable variability of the neurologic structures that will be encountered, which is described in this technical note.

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  • Mitsuru Furukawa, Kunimasa Okuyama, Ken Ninomiya, Takeshi Miyamoto, Yo ...
    Article ID: 2021-0149
    Published: 2022
    Advance online publication: April 12, 2022
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION
    Supplementary material

    Introduction: Although patients with diffuse idiopathic skeletal hyperostosis (DISH) do not have low bone density, it is a risk factor for spine fractures associated with DISH. We investigated the characteristics and bone metabolism markers of patients with DISH having low bone density to assess whether osteoporosis medication is necessary to prevent fractures.

    Methods: A cross-sectional study was conducted between April 1, 2008, and March 31, 2019. The 86 patients included were divided into two groups according to their T-scores—one group had low bone density and DISH, and the other group did not. Group A (T-score ≤ −1) and B (T-score > −1) data were adjusted for confounding factors and compared for differences in age, body weight, maximum number of vertebral bodies with bony bridges between adjacent vertebrae (max VB), and previous history (hypertension, malignant tumors, diabetes mellitus, cardiac diseases, chronic renal failure, and spinal fractures). In Group A, multiple linear regression was used to investigate relationships among max VB, femur bone mineral density (BMD), total type I procollagen N-terminal propeptide (P1NP), and tartrate-resistant acid phosphatase 5b (TRACP-5b).

    Results: Group A had 36, and Group B had 50 male patients with DISH. Patients in Group B were heavier than those in Group A. The mean femur BMD in Group A was age-appropriate, and that in Group B was higher than the age-appropriate femur BMD. The mean values of P1NP and TRACP-5b were within the normal range. Max VB was positively correlated with total P1NP in Group A. Total P1NP was significantly and positively correlated with TRACP-5b.

    Conclusion: The DISH group with a T-score of ≤−1 was age-appropriate. The group with a T-score of >−1 had higher BMD because of their higher body weight. The group with a T-score of ≤−1 had good bone metabolism and did not require aggressive osteoporosis treatment.

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  • Takuhei Kozaki, Hiroshi Hashizume, Hiroyuki Oka, Satoru Ohashi, Yoh Ku ...
    Article ID: 2021-0231
    Published: 2022
    Advance online publication: April 12, 2022
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    Introduction

    Adult spinal fusion surgery improves lumbar alignment and patient satisfaction. Adult spinal deformity surgery improves saggital balance not only lumbar lesion, but also at hip joint coverage. It was expected that hip joint coverage rate was improved and joint stress decreased. However, it was reported that adjacent joint disease at hip joint was induced by adult spinal fusion surgery including sacroiliac joint fixation on an X-ray study. The mechanism is still unclear. We aimed to investigate the association between lumbosacral fusion including sacroiliac joint fixation and contact stress of the hip joint.

    Methods

    A 40-year-old woman with intact lumbar vertebrae underwent computed tomography. A three-dimensional nonlinear finite element model was constructed from the L4 vertebra to the femoral bone with triangular shell elements (thickness, 2 mm; size, 3 mm) for the cortical bone's outer surface and 2-mm (lumbar spine) or 3-mm (femoral bone) tetrahedral solid elements for the remaining bone. We constructed the following four models: a non-fusion model (NF), a L4-5 fusion model (L5F), a L4-S1 fusion model (S1F), and a L4-S2 alar iliac screw fixation model (S2F). A compressive load of 400 N was applied vertically to the L4 vertebra and a 10-Nm bending moment was additionally applied to the L4 vertebra to stimulate flexion, extension, left lateral bending, and axial rotation. Each model's hip joint's von Mises stress and angular motion were analyzed.

    Results

    The hip joint's angular motion in NF, L5F, S1F, and S2F gradually increased; the S2F model presented the greatest angular motion.

    Conclusions

    The average and maximum contact stress of the hip joint was the highest in the S2F model. Thus, lumbosacral fusion surgery with sacroiliac joint fixation placed added stress on the hip joint. We propose that this was a consequence of adjacent joint spinopelvic fixation. Lumbar-to-pelvic fixation increases the angular motion and stress at the hip joint.

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  • Tomoki Naka, Tetsuo Hayashi, Atsushi Sugyo, Fumihiro Towatari, Takeshi ...
    Article ID: 2021-0240
    Published: 2022
    Advance online publication: April 12, 2022
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    Introduction: Recently, the cases of elderly individuals with spinal cord injuries are increasing in Japan. For individuals with spinal cord injury, regaining the ability to walk independently after an injury is one of the most important aspects of rehabilitation. Nevertheless, instead of age-optimized programs, uniform rehabilitation programs are currently provided to all patients because there is no information available for predicting prognosis based on age at the time of injury. This study aimed to elucidate the effect of age at the time of injury on the walking ability of patients with incomplete cervical spinal cord injury.

    Methods: Of the 1,195 patients registered in the Japan single-center study for spinal cord injury database, those hospitalized within 28 days after injury, followed up for >180 days, had a cervical spinal cord injury, and had a lower extremity motor score of ≥42 points were examined. Patients were stratified into three groups according to the age at the time of injury (≤59, 60–69, or ≥70 years). The walking ability scores and independence levels of mobility were compared; these data were evaluated based on indoor mobility (item 12) and outdoor mobility (item 14) in the Spinal Cord Independence Measure III and Walking Index for Spinal Cord Injury II. All comparisons used data at discharge.

    Results: The walking ability scores and independence levels of mobility were significantly lower in the group aged ≥70 years than those in the remaining two groups.

    Conclusions: In patients with cervical spinal cord injuries with the same limb function, if the age at the time of injury was ≥70 years, the decline in physical function due to aging exerted a substantial effect on walking ability.

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  • Hideaki Nakajima, Shuji Watanabe, Kazuya Honjoh, Arisa Kubota, Hideaki ...
    Article ID: 2021-0248
    Published: 2022
    Advance online publication: April 12, 2022
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    Introduction: The number of patients with degenerative cervical myelopathy (DCM) requiring surgical treatment has markedly increased in today' s aging society. Such patients often exhibit impaired activities of daily living because of motor dysfunction as well as neuropathic pain (NeP). Although many studies have demonstrated the safety and efficacy of surgical treatment for DCM, residual postoperative NeP has not been well described. Therefore, this study aimed to identify the predictors of postoperative NeP improvement in patients with DCM.

    Methods: This retrospective study included 92 outpatients with postoperative chronic NeP (≥3 months) related to DCM. Data were obtained from clinical information, magnetic resonance imaging (MRI) findings, and patient-based questionnaires using the Neuropathic Pain Symptom Inventory (NPSI) and the Brief Scale for Psychiatric Problems in Orthopaedic Patients. Univariate and multivariate analyses were performed for patients with NPSI improvement rates <30% and ≥30% to identify prognostic factors.

    Results: Among 92 patients, 61 (66.3%) had residual NeP, with a low improvement rate even after surgery. The independent negative prognostic factors for NeP improvement after surgery were older age at operation (odds ratio (OR): 0.932), longer symptom duration before surgery (OR: 0.589), and higher preoperative NPSI score (OR: 0.932). The cut-off value of symptom duration before surgery for postoperative NeP improvement was 1 year. By contrast, the preoperative Japanese Orthopaedic Association score and MRI findings, including signal intensity change and the degree of spinal cord compression, were not associated with postoperative NeP improvement. Moreover, even in patients with an NPSI improvement rate ≥30%, the NPSI subscores for deep pain and paresthesia/dysesthesia remained high.

    Conclusions: Discrepancies between physician- and image-based assessments and patient-based assessments were identified as factors associated with improvement in postoperative NeP. Our findings are important for both spine surgeons and patients to manage patient expectations with respect to recovery during the postoperative course.

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  • Inamullah Khan, Scott L. Parker, Hansen Bow, Ahilan Sivaganesan, Jacqu ...
    Article ID: 2021-0252
    Published: 2022
    Advance online publication: April 12, 2022
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    Background: Surgical management of degenerative lumbar spine disorders is effective at improving patient pain, disability, and quality of life; however, obtaining a durable posterolateral fusion after decompression remains a challenge. Interbody fusion technologies are viable means of improving fusion rates in the lumbar spine, specifically various graft materials including autograft, structural allograft, titanium, and polyether ether ketone. This study assesses the effectiveness of Tritanium posterolateral cage in the treatment of degenerative disk disease.

    Methods: Nearest-neighbor 1:1 matched control transforaminal lumbar interbody fusion with PEEK vs. Tritanium posterior lumbar (PL) cage interbody fusion patients were identified using propensity scoring from patients that underwent elective surgery for degenerative disk diseases. Line graphs were generated to compare the trajectories of improvement in patient-reported outcomes (PROs) from baseline to 3 and 12 months postoperatively. The nominal data were compared via the χ2 test, while the continuous data were compared via Student's t-test.

    Results: The two groups had no difference regarding either the 3- or 12-month Euro-Qol-5D (EQ-5D), numeric rating scale (NRS) leg pain, and NRS back pain; however, the Tritanium interbody cage group had better Oswestry Disability Index (ODI) scores compared to the control group of the PEEK interbody cage at both 3 and 12 months (p = 0.013 and 0.048).

    Conclusions: Our results indicate the Tritanium cage is an effective alternative to the previously used PEEK cage in terms of PROs, surgical safety, and radiological parameters of surgical success. The Tritanium cohort showed better ODI scores, higher fusion rates, lower subsidence, and lower indirect costs associated with surgical management, when compared to the propensity-matched PEEK cohort.

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  • Gentaro Kumagai, Kanichiro Wada, Toru Asari, Yoshiro Nitobe, Yasuyuki ...
    Article ID: 2021-0263
    Published: 2022
    Advance online publication: April 12, 2022
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    Introduction: The aim of this study was to investigate the association of methicillin-resistant coagulase-negative staphylococci (MRCNS) on preoperative skin and surgical site infections (SSIs) in patients undergoing spinal surgery.

    Methods: A total of 507 cases (239 males and 268 females; mean age: 56.1 years) were included in this retrospective study, using prospectively collected data. All patients underwent skin culturing of the surgical site preoperatively. To identify independent risk factors for SSIs as the dependent variable, sequential multivariate logistic regression analyses were conducted. Age, sex, body mass index, presence of rheumatoid arthritis (RA), steroid uses, the American Society of Anesthesiologists Physical Status (ASA-PS) ≥3, MRCNS-positivity on skin bacterial culture, instrumentation, and Japanese Orthopedic Association (JOA) score were used as independent variables.

    Results: Preoperatively, MRCNS was detected from skin culture in 50 (9.9%) cases. The frequency of RA, steroid uses, and ASA-PS ≥3 was significantly higher in MRCNS-positive cases than in MRCNS-negative cases. There were 21 (4.1%) post-spinal surgery SSI cases. Multivariate logistic regression analyses revealed that JOA scores (odds ratio (OR), 0.864; 95% confidence interval (CI), 0.764–0.977) and MRCNS-positivity (OR, 5.060; 95% CI, 1.787–14.323) were significantly associated with SSIs.

    Conclusions: Preoperatively, the incidence of MRCNS was 9.9%; it was the most common cause of postoperative SSIs. MRCNS-positivity was the most associated factor for SSIs.

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  • Yoshihito Sakai, Tsuyoshi Watanabe, Norimitsu Wakao, Hiroki Matsui, Na ...
    Article ID: 2021-0269
    Published: 2022
    Advance online publication: April 12, 2022
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    Proprioception is a deep sensation that perceives the position of each part of the body, state of movement and muscle contraction, and resistance and mass applied to the body. Proprioceptive feedback influences movement and positional accuracy, resulting in key somatosensory functions for human postural control. Proprioception encompasses signals received from proprioceptors located in the skin, subcutaneous tissue, muscles, tendons, and joint capsules, commonly known as mechanoreceptors. The muscle spindle, a crucial proprioceptor, is stretched during eccentric contraction of muscle, thus generating an action potential on afferent fibers to convey a proprioceptive information to the sensorimotor cortex in the brain. For exercise therapy in patients with locomotor disease, proprioception serves an essential function for motor control; thus, this should be considered to obtain effective muscle output. As postural control is achieved by proprioceptive function according to the balance between the lower limb and trunk, relative proprioceptive weighting ratio can help clarify proprioceptive control using muscle response to mechanical vibration. The absence of proprioceptive information congruent with motor intention activates cortical center monitoring incongruence of sensation, leading to pathological pain. Therapeutic procedures may aim to restore the integrity of cortical information processing in musculoskeletal chronic pain. Poor proprioception is one of the main causes of decreased postural balance control in elderly patients with low back pain (LBP). It has been hypothesized that proprioception of the lower limbs deteriorates with age-related muscle mass loss (sarcopenia), which increases the proprioceptive burden on the lumbar spine. Accurate diagnosis of the proprioceptive function is important for establishing a treatment procedure for proprioceptive recovery, and further prospective research is required to clarify the relationship between proprioception and LBP improvement.

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  • Yasushi Iijima, Takeo Furuya, Toshiaki Kotani, Tsuyoshi Sakuma, Keita ...
    Article ID: 2021-0270
    Published: 2022
    Advance online publication: April 12, 2022
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  • Masanari Takami, Yasuhiro Iwasaki, Motohiro Okada, Keiji Nagata, Naoak ...
    Article ID: 2022-0001
    Published: 2022
    Advance online publication: April 12, 2022
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    Introduction

    Massive hemothorax due to thoracic vertebral fractures (MHTVF) is a potentially lethal condition; however, its epidemiological and clinical data have been rarely described. Thus, in this study, we aimed to evaluate the incidence, predictive factors, and clinical features of MHTVF.

    Methods

    This retrospective cohort study enrolled 202 consecutive patients (136 male and 66 female patients) with thoracic vertebral fractures treated at our institute between January 2009 and December 2019. Their mean age was 60.7 (range, 17–90) years. Unstable fractures accounted for 57.4% (n = 116) of the total fractures. The patients were then divided into MHTVF and non-MHTVF groups. We assessed the following MHTVF-associated factors: sex, age, history of medical conditions, anticoagulation/antiplatelet drug use, injury severity score, anatomical distribution of levels of the vertebral fractures, fracture type, and presence or absence of diffuse idiopathic skeletal hyperostosis (DISH) fracture.

    Results

    In total, eight patients (six men and two women) with a mean age of 68.9 years (range, 22–85 years) were determined to exhibit MHTVF. The incidence of MHTVF in patients with unstable thoracic spinal fractures was 6.9%, whereas none of those with stable spinal fractures exhibited MHTVF. Factors like type B (p = 0.049) and DISH (p = 0.017) fractures were noted to be significantly associated with the MHTVF. Three patients experienced shock upon arrival, whereas two exhibited delayed shock. Chest tube insertion and/or emergency thoracotomy was performed. The survival rate was 100.0%.

    Conclusions

    MHTVF is not rare. Because type B and DISH fractures are identified as predictive factors of MHTVF, it must be carefully treated to avoid preventable death even after hospitalization in patients with these thoracic fractures.

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  • Atsuhiro Yoshida, Tsutomu Akazawa, Yoshiaki Torii, Jun Ueno, Masahiro ...
    Article ID: 2022-0006
    Published: 2022
    Advance online publication: April 12, 2022
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    Introduction

    The alpha-defensin lateral flow test has been used in periprosthetic joint infection as a diagnostic support tool because of its simplicity and speed. However, the test has not been used to diagnose spinal infections. The purpose of this study was to investigate the efficacy of the alpha-defensin lateral flow test for diagnosing spinal infections.

    Methods

    The subjects were 11 patients who were suspected of having spinal infections from October 2019 to August 2021 and underwent biopsies at a single institution. There were nine male and two female patients, with an average age of 60.7 (14–87) years. For diagnosing infection, the patient's consent for biopsy was obtained, and the sample was collected by computed tomography-guided aspiration biopsy or open biopsy at the site considered to be a possible abscess. The samples were subjected to a bacterial culture test, an acid-fast bacillus culture test, and an alpha-defensin lateral flow test (Synovasure® lateral flow test; Zimmer Biomet, IN, USA).

    Results

    Of the 11 suspected spinal infections, the alpha-defensin lateral flow test was positive in 8 cases, negative in 2 cases, and undeterminable in 1 case. Of the 10 cases excluding the undeterminable case, the definitive diagnosis was 9 cases of spinal infection (spondylitis: 6 cases, spinal implant infection: 3 cases) and 1 case of vertebral body fracture. The alpha-defensin lateral flow test demonstrated a sensitivity of 88.9%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 50%. The biopsy sample culture test demonstrated a sensitivity of 77.8%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 33.3%.

    Conclusions

    We suggested that the alpha-defensin lateral flow test might be useful as a diagnostic support tool for spinal infections.

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  • Kentaro Yamada, Makoto Ieguchi, Shinji Takahashi, Hiroaki Nakamura
    Article ID: 2022-0021
    Published: 2022
    Advance online publication: April 12, 2022
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    Introduction: Pyogenic vertebral osteomyelitis (PVO) is an uncommon but life-threatening infectious disease. Diffuse idiopathic skeletal hyperostosis (DISH) is an age-related disorder and sometimes problematic in terms of spinal instability or high mortality, especially in cases of DISH-related fracture. Meanwhile, no reports have focused on the impact of DISH on the clinical outcomes after treatment for PVO. We hypothesized that PVO occurring at DISH-related segments might contribute to poor clinical results or high mortality rates. The purpose of this study was to investigate the impact of DISH on mortality after treatment for PVO in a retrospective cohort study.

    Methods: This study involved patients who were hospitalized and treated for PVO at a single institution. DISH-related PVO was defined as PVO within a segment ossified by DISH or PVO at the neighboring intervertebral level of the segment ossified by DISH. Differences in mortality between patients with DISH-related and non-DISH-related PVO were investigated.

    Results: This study included 55 patients. DISH-related PVO was observed in 13 patients. The mortality rate was significantly higher in patients with DISH-related PVO than in those with non-DISH-related PVO (62% and 23%, respectively; p = 0.016). Propensity score-adjusted analysis showed that DISH-related PVO was an independent risk factor for mortality (adjusted hazard ratio, 2.79; p = 0.034). The survival probability was significantly shorter in patients with DISH-related PVO than in those with non-DISH-related PVO (p = 0.006). PVO in which the intravertebral body was the center of involvement was significantly more common in DISH-related PVO than in non-DISH-related PVO (38% and 5%, respectively; p = 0.006).

    Conclusions: DISH-related PVO was associated with a higher mortality rate and shorter life expectancy than non-DISH-related PVO. Similar to advanced age, PVO at the segment ossified by DISH should be recognized as a risk factor for mortality when choosing the optimal treatment strategy.

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  • Toshio Nakamae, Naosuke Kamei, Nobuhiro Tanaka, Kazuyoshi Nakanishi, Y ...
    Article ID: 2022-0024
    Published: 2022
    Advance online publication: April 12, 2022
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  • Vahideh Moradi, Amir-Hossein Memari, Marjan Saeedi, Sanaz Nadernejad, ...
    Article ID: 2021-0051
    Published: 2022
    Advance online publication: March 04, 2022
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    Introduction: This study investigated brace-related stress, trunk appearance perception, and quality of life in adolescent girls with idiopathic scoliosis who wear the Milwaukee brace for treatment.

    Methods: Fifty-two adolescent girls with idiopathic scoliosis participated in this study. They had been under treatment with Milwaukee brace for at least three months. They filled out four questionnaires, including the revised 22-item Scoliosis Research Society questionnaire (SRS-22r), the Brace Questionnaire (BrQ), the Bad Sobernheim Stress Questionnaire-Brace (BSSQ-Brace), and the Trunk Appearance Perception Scale (TAPS).

    Results: Twenty participants had high stress levels, and thirty-two had moderate stress levels. The total score and emotional and social function scores of the BrQ were significantly higher in participants with high stress compared to those with moderate stress. There was no significant difference between the two groups in the SRS-22r and TAPS questionnaires scores. However, a high Cobb angle had significantly worsened their perception of trunk appearance.

    Conclusions: It seems that among quality-of-life parameters, social and emotional functions are more affected by stress level in treating adolescent girls with idiopathic scoliosis with a brace. In addition, patients with high stress levels have a worse perception of their trunk appearance.

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  • Jui-Yang Hsieh, Shao-Ming Chuang, Chen-Sheng Chen, Jyh-Horng Wang, Po- ...
    Article ID: 2021-0197
    Published: 2022
    Advance online publication: March 04, 2022
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    Supplementary material

    Introduction: There are various surgical interventions to manage osteoporotic vertebral compression fracture. Modular spine block (MSB) is a novel intravertebral fixator that can be assembled. This study aimed to quantitatively investigate the force distribution in vertebrae with the various structural designs and implantation methods by finite element analysis (FEA).

    Methods: A three-dimensional nonlinear FEA of the L3 implanted with MSB was constructed. Different structural designs (solid vs. hollow) and implantation methods (three-layered vs. six-layered and unilateral vs. bilateral) were studied. The model was preloaded to 150 N-m before the effects of flexion, extension, torsion, and lateral bending were analyzed at the controlled ranges of motion of 20°, 15°, 8°, and 20°, respectively. The resultant intervertebral range of motion (ROM) and disk stress as well as intravertebral force distribution were analyzed at the adjacent segments.

    Results: The different layers of MSB provided similar stability at the adjacent segments regarding the intervertebral ROM and disk stress. Under stress tests, the force of the solid MSB was shown to be evenly distributed within the vertebrae. The maximum stress value of the unilaterally three-layered hollow MSB was generally lower than that of the bilaterally six-layered solid MSB.

    Conclusions: The MSB has little stress shielding effect on the intervertebral ROM and creates no additional loading to the adjacent disks. The surgeon can choose the appropriate numbers of MSB tofix vertebrae without worrying about poly (methyl methacrylate) extravasation, implant failure, or adjacent segment disease.

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  • Hirotaka Kurata, Tomoaki Koakutsu, Shinji Ogawa, Yasuo Yamada, Atsutak ...
    Article ID: 2021-0213
    Published: 2022
    Advance online publication: March 04, 2022
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  • Shota Katayama, Chikara Ushiku, Taku Ikegami, Takeshi Inoue, Akira Shi ...
    Article ID: 2021-0219
    Published: 2022
    Advance online publication: March 04, 2022
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  • Takeshi Sasaki, Daisuke Kurosawa, Eiichi Murakami
    Article ID: 2021-0239
    Published: 2022
    Advance online publication: March 04, 2022
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    Introduction: Most sacroiliac joint (SIJ) disorders are conservatively treated; however, patients with severe pain occasionally require SIJ arthrodesis after failure of continuous conservative management for more than 6 months. We investigated the incidences of preoperative tenderness in the sacrotuberous ligament (STL) and postoperative lower-buttock pain originating from the STL to determine the best way to manage these symptoms to achieve good outcomes.

    Methods: We retrospectively investigated 33 patients (14 men and 19 women) with a mean age of 47.7 years (range: 25–79 years) who underwent SIJ arthrodesis for severe pain confirmed using diagnostic SIJ injections between April 2009 and December 2019. We investigated the pain improvement at or around the posterior superior iliac spine (PSIS) pre- and postoperatively using the visual analogue scale (VAS) values, incidence of tenderness of the STL before surgery, rate of the persisting STL tenderness, incidence of new-onset STL pain, and treatment options for STL pain postoperatively.

    Results: The mean VAS value at or around the PSIS was significantly relieved postoperatively from 85.6 to 31.5 mm (P < 0.001). Preoperative tenderness of the STL was identified in 21 of 33 patients (63.6%). The STL tenderness resolved after surgery in 12 of these 21 patients (57.1%); however, it persisted in nine patients (42.9%), all of whom were women. Of the 12 patients who did not have preoperative STL tenderness, 4 (33.3%) developed lower-buttock pain and had STL tenderness. In total, 9 (27.3%) of the 33 patients whose progress could be followed up after SIJ arthrodesis had pain originating from the STL; the STL pain in 8 of the 9 patients was relieved after the STL injections and physical therapy.

    Conclusions: The STL pain can occur pre- and postoperatively, and management of both persisting and new-onset STL pain after SIJ arthrodesis should be considered to achieve better outcomes.

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  • Takuya Kasamasu, Yuko Ishida, Masahiro Sato, Yasuyoshi Mase, Koichi Sa ...
    Article ID: 2021-0242
    Published: 2022
    Advance online publication: March 04, 2022
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    Introduction: Lumbar spondylolysis is common in pediatric athletes, and many athletes can return to sports with conservative treatment. There are two initial treatment strategies: bony union or pain management, but the outcomes of these strategies have not been clarified. The purpose of this study is to investigate the rates of return to sports (RTS) and recurrence in pediatric athletes after conservative treatment for lumbar spondylolysis and to compare both treatment strategies.

    Methods: A total of 180 patients with lumbar spondylolysis were managed with a trunk brace and cessation of sports activity (bone union [BU] group, n = 95) or treated for pain only (pain management [PM] group, n = 85). RTS and recurrence rates according to type of conservative treatment were compared.

    Results: The RTS rate was 98.9% in the BU group and 97.6% in the PM group at 4.7 ± 1.9 and 1.8 ± 1.7 months, respectively. Recurrence occurred in 7.4% of patients in the BU group at 19.0 ± 16.0 months and in 4.8% of the PM group at 17.8 ± 5.2 months.

    Conclusions: The RTS rate in pediatric athletes with lumbar spondylolysis was high at more than 95%, regardless of type of conservative treatment. The mean time to RTS was longer in the BU group than in the PM group (4.7 vs. 1.8 months) because of the time required for bone healing. There were several cases of recurrence after RTS. Strategies to prevent recurrence of lumbar spondylolysis in pediatric athletes are discussed.

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  • Erik B. Gerlach, Alexandra R. Richards, Mark A. Plantz, David J. Fei-Z ...
    Article ID: 2021-0267
    Published: 2022
    Advance online publication: March 04, 2022
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    Study Design: Narrative Review

    Objective: To summarize the main findings from research on measuring the value in spine surgery.

    Summary of Background Data: Determining the value of surgical interventions, which is defined by the quality and efficacy of care received divided by the cost to deliver healthcare, is inherently complex. The two most fundamental components of value—quality and total cost—are multifactorial and difficult to quantify.

    Methods: A narrative review of all the relevant papers known to the author was conducted.

    Results: It is straightforward to calculate the aggregate hospital cost following a surgical procedure, but it is not simple to estimate the total cost of a procedure—including the direct and indirect costs. These individual metrics can help providers make more educated decisions with regards to improving patient quality of life and minimizing unnecessary costs. A consensus of the appropriate cost-per-quality-adjusted life-year threshold of different spine surgeries needs to be established. As these metrics become more commonplace in spine surgery, the potential for personalized health care will continue to be developed.

    Conclusions: As the healthcare system shifts toward value-based care, there is a substantial need for research assessing the value as defined by the quality and efficacy of care received divided by the cost to deliver healthcare of specific spine surgery procedures. Studies on different predictors—both patient-specific and surgical—that may influence outcomes, cost, and value are required.

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  • Prashasth Belludi Suresh, Sarvdeep Singh Dhatt, Vishal Kumar, Amit Kum ...
    Article ID: 2021-0137
    Published: 2022
    Advance online publication: February 10, 2022
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    Supplementary material

    Introduction: This prospective randomized controlled study aimed to examine the role of modest systemic hypothermia in individuals with acute cervical spinal cord injury (SCI) regarding neurological improvement. Studies have shown that the application of hypothermia is safe and that it improves neurological outcomes in patients with traumatic spine injury. Hypothermia helps in decreasing a secondary damage to the cord.

    Methods: Twentycases of acute post-traumatic cervical SCI with AISA were selected and randomly divided into two treatment groups: Group A—Hypothermia with surgical decompression and stabilization; and Group B—Normothermia with surgical decompression and stabilization. American Spinal Injury Association (ASIA) motor and sensory scores were evaluated at presentation; post-surgery; and at a 2-week, 6-week, and 12-week follow-up.

    Results: At the final follow-up, the change in ASIA motor scores of Group A was 46 (11.5–70.5) and Group B 13 (4.5–58.0), whereas ASIA sensory scores were 118 (24.75–186.5) and 29 (15.25–124.0) in Group A and Group B, respectively. ASIA scores between the two groups were statistically significantly different at a 2-week follow-up (ASIA motor p=0.04, ASIA sensory p=0.006), showing early improvement in the hypothermia group. There was no significant difference between the two groups on further follow-up.

    Conclusion: Hypothermia can be applied safely to subjects with acute SCI. Our study showed that hypothermia was beneficial in the early improvement of functional outcomes in acute cervical SCI.

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  • Reina Miyamoto, Takashi Hirai, Toshitaka Yoshii, Hiroaki Onuma, Hiroyu ...
    Article ID: 2021-0186
    Published: 2022
    Advance online publication: February 10, 2022
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  • Hideo Kinjo, Takanao Shimabukuro, Chikashi Yamakawa, Shogo Fukase, Yas ...
    Article ID: 2021-0191
    Published: 2022
    Advance online publication: February 10, 2022
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  • Fumihiro Arizumi, Keishi Maruo, Kazuya Kishima, Norichika Yoshie, Tomo ...
    Article ID: 2021-0193
    Published: 2022
    Advance online publication: February 10, 2022
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    Introduction: Reports of myelopathy with C7 anterior spondylolisthesis are extremely rare, and the surgical outcomes, clinical features, and their effects remain unknown. We describe six patients who underwent surgery for C7 spondylolisthesis with myelopathy.

    Methods: Six patients who underwent operative treatment for C7 spondylolisthesis with myelopathy were retrospectively reviewed. C7 spondylolisthesis was defined as an anterior slippage of more than 2 mm on X-ray or computed tomography (CT). The images were evaluated using radiography, magnetic resonance imaging (MRI), and CT. Clinical outcomes were evaluated using the thoracic Japanese Orthopedic Association (T-JOA) score and Frankel grade.

    Results: Facet joint arthrosis was observed in all patients at the C7/T1 level. MRI revealed a juxta-facet cyst in the spinal segment in three cases and a high signal change in four cases. We could visualize C7 anterior slippage from the lateral radiograph in one case. The mean time from onset to diagnosis was 95 (range, 7–280) months. Posterior spinal fusion using pedicle screws and interlaminectomy was performed in five cases. Cystectomy with partial laminectomy was performed in one case with a juxta-facet cyst. The mean JOA score was 6 ± 0.7 preoperatively and improved to 9 ± 1.5 at the final follow-up. The Frankel grades of all patients improved by more than one grade.

    Conclusions: In this study, myelopathy with C7 spondylolisthesis was relatively severe, and we believe that the mechanical stress between the rigid thoracic vertebrae and the movable cervical spine may cause C7 spondylolisthesis. Posterior spinal fusion and partial laminectomy for C7 spondylolisthesis with myelopathy resulted in satisfactory outcomes.

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  • Shizumasa Murata, Hiroshi Iwasaki, Masanari Takami, Keiji Nagata, Hiro ...
    Article ID: 2021-0196
    Published: 2022
    Advance online publication: February 10, 2022
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    Introduction: Sacroiliac joint pain (SIJP) is one of the pathological conditions of adjacent segment disorders occurring after adult spinal deformity (ASD) surgery. This study aimed to test the hypothesis that even in ASD surgery using S2 alar-iliac (S2AI) screws, SIJP can develop much earlier than reported previously and can be rescued by ultrasound-guided sacroiliac joint block.

    Methods: Overall, 94 patients with ASD treated with long spinal fusion using S2AI screws were prospectively investigated for SIJP postoperatively, and the effect of ultrasound-guided sacroiliac joint block was evaluated. Additionally, the relationship between the symptomatic side of the SIJP and the surgical procedure; the preoperative and postoperative whole-spine sagittal and coronal alignment, lumbar pelvis sagittal plane alignment, and pelvic incidence-lumbar lordosis were retrospectively compared between the groups with and without SIJP.

    Results: Eleven of 94 cases (11.7%) developed SIJP. The average onset was 12.0 (±6.2) days after surgery. The "one-finger test," "Gaenslen test," and "tenderness of the posterosuperior iliac spine" had high positivity rates for SIJP. Night pain occurred in 81.8% of patients and was one of the diagnostic features. There were no significant relationships between the symptomatic side of SIJP and the approach-side of lumbar interbody fusion, donor site of the iliac bone graft, or malposition of the S2AI screw. There were no significant differences in preoperative characteristics and radiological parameters between the SIJP-positive and -negative groups preoperatively, postoperatively, or in postoperative changes. Two of the 11 cases required the SIJ block four times, but all patients eventually achieved >70% pain relief with no recurrence.

    Conclusions: For good pain control and physical therapy, the fact that early buttock–groin pain after spinal fusion surgery has a 12% likelihood of being due to SIJP and can be relieved with the ultrasound-guided SIJ block is clinically important for diagnosis and pain management.

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  • Tatsuya Yasuda, Yu Yamato, Tomohiko Hasegawa, Go Yoshida, Tomohiro Ban ...
    Article ID: 2021-0199
    Published: 2022
    Advance online publication: February 10, 2022
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    Introduction

    Proximal junctional failure (PJF) and rod fracture (RF) are the primary reasons for revision surgery after a long corrective fusion for the adult spinal deformity (ASD). However, many recent studies on ASD are multicenter studies from the US and European racial characteristics may differ from those of Asians. Therefore, the risk factors for revision surgery because of PJF and RF after ASD surgery were evaluated in Japanese patients.

    Methods

    Patients with ASD who underwent corrective surgery from the thoracic vertebrae to the ilium at the authors' institution were reviewed. Demographic, surgical, and radiographic parameters were included in the analysis. Univariate and multivariate regression models were used to analyze the risk factors for PJF and RF.

    Results

    Two hundred and fifty-nine patients were included in the study. A total of 73 patients (28.1%) required revision surgery because of mechanical complications and 15 patients (5.7%) required revision surgery because of PJF on average 380 days after surgery. In PJF cases, body mass index (BMI) and pelvic tilt were significantly higher (p = 0.01, p = 0.048, respectively). BMI was an independent risk factor for revision owing to PJF (odds ratio [OR], 1.16; p = 0.013). A total of 49 patients (18.9%) required revision owing to RF on average867 days after surgery. Three-column osteotomy (p < 0.001), significant blood loss (p = 0.048), number of fusion segments (p = 0.023), absence of lateral lumbar interbody fusion (p < 0.001), and sagittal imbalance (p = 0.033) were risk factors for revision surgery owing to RF in the univariate analysis. Three-column osteotomy (OR 4.41; p < 0.001) and number of fusion segments (OR 1.21; p < 0.009) were independent factors for revision surgery owing to RF.

    Conclusion

    PJF occurred in a relatively early phase (approximately 1 year) after surgery in patients with ASD with high BMI. Conversely, RF occurred approximately 2.5 years after surgery in three-column osteotomy and spinal fusion cases that involvedlonger fusion range.

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  • Shizumasa Murata, Keiji Nagata, Hiroshi Iwasaki, Hiroshi Hashizume, Ya ...
    Article ID: 2021-0200
    Published: 2022
    Advance online publication: February 10, 2022
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    Introduction: Long-term clinical outcomes of microendoscopic laminotomy (MEL) for patients with multilevel radiographic lumbar spinal canal stenosis (LSS) have not been widely explored. The clinical significance and natural progression of additional untreated levels (e.g., remaining radiographic (RR) -LSS not addressed by selective MEL) remain unknown. This retrospective study aimed to investigate the long-term clinical outcomes of selective MEL in LSS patients and compare outcomes between patients with and without remaining RR-LSS to determine the efficacy of this procedure.

    Methods: Forty-nine patients at a single center underwent posterior spinal microendoscopic decompression surgery for neurogenic claudication or radicular leg pain in moderate-to-severe spinal stenosis. The patients were categorized into the RR-LSS-positive and RR-LSS-negative cohorts based on unaddressed levels of stenosis. Pre-operative and 10-year follow-up evaluations, including the Japanese Orthopedic Association (JOA) score, visual analog scale (VAS) score for low back pain and leg pain, Oswestry Disability Index (ODI), and satisfaction, were compared between the groups. Additionally, the need for reoperation was determined.

    Results: MEL significantly improved JOA scores, lumbar VAS, and ODI over the 10-year postoperative period. Pre-operative characteristics and postoperative outcomes were not significantly different between the cohorts. Overall, 18.4% (9/49) of patients required reoperation during the follow-up period. The reoperation rate in the RR-LSS-positive (13.8%; 4/29) group was similar to that in the RR-LL-negative (15.0%; 3/20) group.

    Conclusions: MEL is effective for lumbar stenosis, with improved clinical outcomes up to 10 years following surgery. Selective MEL, addressing only symptomatic levels in multilevel stenosis, with residual remaining lumbar stenosis, is similarly effective without increased reoperation rates. Surgeons may consider more limited selective decompression in patients with multilevel stenosis, avoiding the risk and invasiveness of extensive procedures.

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  • Naoyuki Nakamura, Masatoshi Oba, Takako Momose, Jiro Machida, Yutaka I ...
    Article ID: 2021-0204
    Published: 2022
    Advance online publication: February 10, 2022
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    【Introduction】

    Spinal fusion for children with neuromuscular scoliosis has been known to improve sitting balance and quality of life as well as for high caregiver satisfaction. However, most studies performed were single surveys, and it remains unclear whether high satisfaction levels are maintained. Thus, in this article, we report the short- and medium-term improvements in caregiver standing assessment after neuromuscular scoliosis surgery in children with Gross Motor Function Classification System (GMFCS) level IV or V.

    【Methods】

    In total, 18 patients with GMFCS levels IV and V were included in this study. The underlying diseases were typical cerebral palsy in 12 cases, chromosomal abnormalities in 5 cases, and congenital myopathy in 1 case. The median age at the time of surgery was 14.5 years. The medians for the first and second follow-up surveys were after 1.4 and 5.9 years, respectively. All the patients had undergone posterior spinal fusion, whereas 12 had undergone pelvic fixation. These patients were assessed using a caregiver questionnaire, in addition to patient demographic data and radiographic assessments.

    【Results】

    The median BMI was 15.4 kg/m2 preoperatively, 16.6 kg/m2 at the first survey, and 17.1 kg/m2 at the second survey. The main Cobb angles were 97.5°, 36.5°, and 37.0° and the spino-pelvic obliquity angles were 22.5°, 6.0°, and 6.5° preoperatively, at the first survey and at the second survey, respectively. In the questionnaire, most domains were rated similarly in the first and second surveys, but the ratings for the "children's QOL" and "digestion and defecation" domains were noted to increase, while that for the "transfer" and "satisfaction with treatment" domains have decreased.

    【Conclusions】

    Neuromuscular scoliosis surgery in children has been associated with extremely high treatment satisfaction in the early postoperative period. However, some caregivers showed a decline in the "transfer" and "treatment satisfaction" domains over time.

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  • Keitaro Matsukawa, Kanehiro Fujiyoshi, Yoshihide Yanai, Takashi Kato, ...
    Article ID: 2021-0207
    Published: 2022
    Advance online publication: February 10, 2022
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    Introduction:

    Vertebral slip reduction has been recommended in arthrodesis for lumbar degenerative spondylolisthesis (LDS) to achieve balanced spinal alignment and bone fusion. However, what determines the degree of slip reduction using cortical bone trajectory technique for lumbar pedicle screw insertion is yet to be determined. Thus, in this study, we aim to investigate the slip reduction capacity using cortical bone trajectory (CBT) technique and to identify factors affecting the slip reduction rate.

    Methods:

    This is a retrospective radiological evaluation of prospectively collected patients. In total, 49 consecutive patients who underwent single-level transforaminal lumbar interbody fusion for LDS using the CBT technique were included (mean follow-up: 28.9 months). Firstly, radiological parameters of fused segment including the percentage of anterior vertebral slip (%slip), lordotic angle, and disk height were measured. Then, patient and procedure-related parameters were examined to determine factors related to the slip reduction rate using multiple regression analysis.

    Results:

    The %slip was reduced from 15.0 ± 4.8 to 1.6 ± 2.3% immediately after surgery and 2.2 ± 2.9% at the last follow-up (p < 0.01), with a slip reduction rate of 87.5 ± 15.7% and correction loss of 0.6 ± 2.1%. As per multivariate regression analysis, it was found that preoperative %slip (standardized regression coefficient [β] = −0.55, p = 0.003) and the depth of screw insertion in the caudal vertebra (β = 0.38, p = 0.03) were significant independent factors affecting slip reduction rate (adjusted R2 = 0.29, p = 0.008).

    Conclusions:

    To the best of our knowledge, this study is the first to investigate the capacity for and factors affecting slip reduction using the CBT technique for LDS. The CBT technique may be a useful option for achieving slip reduction, and the depth of screw insertion in the caudal vertebra was identified as a significant technical factor to obtain a more significant reduction of slipped vertebra.

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  • William H. Waddell, Benjamin M. Weisenthal, Nicholas Golinvaux, Abigai ...
    Article ID: 2021-0210
    Published: 2022
    Advance online publication: February 10, 2022
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    Introduction: Laminoplasty is a well-established technique used to manage cervical myelopathy (CM). Nevertheless, the degree to which United States surgeons have adopted laminoplasty from Japan to treat CM is less clear. The purpose of this study was to compare operative management strategies for CM in the United States (US) with Japan.

    Methods: This study used a retrospective cohort of 16,084 patients from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database and 389,872 patients from the Japanese Diagnosis Procedure Combination (DPC) database from 2007 to 2015. Patients with the following diagnoses were collected: spondylosis with myelopathy (ICD-19; 721.1, ICD-10; M47.12) and disk herniation with myelopathy (ICD-9; 722.71, ICD-10; M50.00). The proportion of surgeries between Japan and the US was compared using a linear regression model controlling for year.

    Results: US surgeons utilized anterior procedures in 70% of cases compared to 9% in Japan (p <.001). In contrast, Japan had significantly more laminoplasties than the US (43% vs. 4%, respectively, p <.001). The percentage of laminoplasty in Japan (43%) relative to the percentage in the US (4%) was significantly different (p <.001). Accounting for increases in the number of total surgeries per year seen in the ACS-NSQIP and DPC databases, no specific surgery demonstrated a significant increase or decrease over the 8 years.

    Conclusion: Japanese surgeons employ laminoplasty to treat CM approximately ten times more frequently than US surgeons who prefer anterior procedures.

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  • Mustafa Ogden, Ulas Yuksel, Mustafa Ilker Karagedik, Ibrahim Umud Bulu ...
    Article ID: 2021-0216
    Published: 2022
    Advance online publication: February 10, 2022
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    Introduction: In this study, it is aimed to compare the long-term results of patients with short-segment instrumentation where screws were inserted into the fractured vertebra with those of patients with long-segment instrumentation applied by skipping the fractured vertebra and reveal the predictive markers in decision-making for screwing fractured vertebra.

    Methods: Patients were separated into two groups, namely, Group A (patients in which the fractured vertebra and vertebrae above and below the fractured vertebra were screwed (short-segment instrumentation, n = 22) and Group B (patients in whom the fractured vertebra was not screwed, whereas two vertebrae above and below the fractured vertebra were screwed (long-segment instrumentation, n = 27).

    Results: The presence of pedicle fracture, AOSpine Classification Scale score, the height of the fractured vertebra, vertebra height below the fractured vertebra, spinal canal diameter, and duration of stay in hospital were different between the groups, preoperatively (p < 0.05). Fractured vertebra height, vertebra height below the fractured vertebra, and Karnofsky Performance Scale score were different between the groups in long-term follow-up (p < 0.05). The preoperative measurement values were similar to each group's postoperative long-term follow-up results. Logistic regression analysis revealed that the presence of pedicle fracture, AOSpine Classification Scale score, vertebra height below the fractured vertebra, and spinal canal diameter could be the best parameters in decision-making for screwing fractured vertebra (p < 0.05).

    Conclusion: Both instrumentation procedures were observed to have similar effectiveness in preventing a collapse in fractured vertebra during long-term follow-up. It was thought that the AOSpine Classification Scale score, presence of pedicle fracture, vertebra height below the fractured vertebra, and spinal canal diameter could be used as predictive markers in decision-making for screwing fractured vertebrae. Consequently, it was concluded that patients with pedicle fractures, more height loss in the vertebra below the fractured vertebra, and narrow spinal canal would not be suitable for screwing the fractured vertebra.

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  • Hideyuki Arima, Tomohiko Hasegawa, Yu Yamato, Go Yoshida, Tomohiro Ban ...
    Article ID: 2021-0220
    Published: 2022
    Advance online publication: February 10, 2022
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    Introduction: Corrective fusion for adult scoliosis often requires fusion from the thoracic spine to the lower lumbar spine or pelvis. However, it is often difficult to determine the lowest instrumented vertebrae (LIV), especially in younger patients. The purpose of this study was to summarize the clinical outcomes and revision surgery rates after corrective fusion for adult scoliosis at different LIV levels in patients under 50 years of age.

    Methods: We retrospectively analyzed 25 patients with adult scoliosis (mean age, 38 years; mean follow-up, 65 months) who underwent corrective fusion from the thoracic spine to L4, L5, or pelvis between 2010 and 2018. Preoperative and at least 2 years' postoperative radiographic parameters, patient-reported outcomes (Scoliosis Research Society-22r [SRS-22r]), mechanical complications, and revision surgery were investigated, and comparisons were made between two groups: the L4 and L5 (L) group (n = 14) and the pelvic group (n = 11).

    Results: Both groups showed a significant improvement in the SRS-22r domains of Self-image and Subtotal postoperatively compared with the baseline (P < 0.05). The incidence of rod fracture was significantly higher in the pelvic group (5 patients, 45%) than in the L group (0 patients, 0%) (P = 0.001). In addition, revision surgery was performed five times in 4 patients (36%) in the pelvic group compared with 0 in the L group (P = 0.068).

    Conclusions: In the L group, clinical outcomes improved in the medium term, with no patients requiring revision surgery. In the pelvic group, the rod fracture rate was higher, but the clinical outcomes improved.

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  • Tatsunori Ikemoto, Atsuhiko Hirasawa, Shoji Kojima, Young-Chang Arai, ...
    Article ID: 2021-0228
    Published: 2022
    Advance online publication: February 10, 2022
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION
    Supplementary material

    Introduction: This study aimed to investigate whether difficulties in some motions concomitant with increased spinal loads would distinguish between patients with and without fresh vertebral compression fractures (VCFs) in elderly patients with acute low back pain.

    Methods: Of the 85 screened patients aged 65 years and older, 80 eligible participants were enrolled. Participants were asked about difficulties (none, slightly, and extreme) in getting up and rolling over and then divided into the VCF group or the non-VCF group after imaging examinations. A logistic regression model was used to determine whether the following variables were associated with the presence of fresh VCFs: age, sex, pain duration, pain severity, and difficulties in getting up and rolling over. Then, a multivariate stepwise logistic regression model was used to determine which variable correlated with the presence of fresh VCFs. Subsequently, we created a key symptom score for the presence of fresh VCFs, and discrimination of fresh VCFs was tested using the receiver operating characteristic (ROC) curve.

    Results: In the multivariate logistic regression analysis, difficulties in getting up (p < 0.05) and rolling over (p < 0.01) were associated with VCFs after controlling for age, sex, and pain severity. As we weighted with 0, 1, or 2 to assess the severity of key symptoms, the score ranged from 0 to 4. The ROC curve showed that scoring of the two key symptoms significantly discriminated participants with or without VCFs with an area under curve = 0.88 (p < 0.001). A score of 2 on the key symptom score showed a sensitivity of 97%, and a score of 4 showed a specificity of 95% for fresh VCFs.

    Conclusions: The results indicate that there may be specific symptoms in elderly patients with fresh VCFs. Scoring of the two key symptoms may be useful for screening fresh VCFs in this population.

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  • Johan L. Heemskerk, Carlos Perez Vega, Ricardo A. Domingo, Kent R. Ric ...
    Article ID: 2021-0073
    Published: 2021
    Advance online publication: December 27, 2021
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    Introduction: Plate distance is correlated with an increased incidence of adjacent segment pathologies (ASP). However, a correct plate-to-disk distance >5 mm is often not achieved. Therefore, this study aimed to quantify the effect of short plate-to-disk distance on the development of ASP using epidemiological measures in patients with cervical degenerative spine disease undergoing single-level anterior cervical discectomy and fusion (ACDFs).

    Methods: Medical records of all patients with cervical degeneration undergoing single-level ACDF with plating (between January 2015 and December 2017), and a follow-up of at least 1 year, were reviewed retrospectively. Radiologic and clinical outcomes were assessed preoperatively, postoperatively, and at last follow-up. The plate-to-adjacent disk distance was measured, and epidemiological measures were calculated to quantify the risk on adjacent-level ossification development (ALOD) and adjacent segment degeneration (ASD).

    Results: Thirty-eight (47.5%) of the 80 patients developed ALOD, and 12 (15.0%) developed ASD after a 2-year follow-up. The incidence of ALOD was significantly lower if the plate was >5 mm away from the adjacent disk space compared to <5 mm (cranial adjacent segment, 22.5% vs. 51.3% [P = 0.010] and caudal, 21.4% vs. 47.8% [P = 0.029]). A correct plate-to-disk distance resulted in a relative risk reduction of 57.2% for the cranial segment and 56.0% for the caudal segment, with a number needed to treat of 4. The ASD was only observed in the cranial adjacent segments, and a correct plate-to-disk distance resulted in a relative risk reduction of 32.1% and a number needed to treat of 18.

    Conclusion: Only four patients need to be treated with a correct plate-to-disk distance to avoid one case of ALOD. Therefore, it isadvisable to keep the plate at a distance >5 mm away from the adjacent disk.

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  • Koichi Murata, Shunsuke Fujibayashi, Bungo Otsuki, Takayoshi Shimizu, ...
    Article ID: 2021-0157
    Published: 2021
    Advance online publication: December 27, 2021
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    Introduction: Several targets have been proposed to achieve satisfactory alignment and favorable outcomes in adult spinal deformity surgery. Stopping the upper instrumented vertebra (UIV) at the thoracolumbar junction levels, especially between T11 and L1, is considered a high-risk factor for the development of proximal junctional kyphosis (PJK). Nevertheless, it is unknown in which patients the results of surgery are satisfactory when L1 or L2 is set as UIV with lumbosacral fixation. This study aimed to identify the risk factors for PJK in patients with lumbosacral fixation with L1 or L2 as UIV.

    Methods: From January 2011 to December 2019, 21 consecutive patients who underwent lumbopelvic fixation for adult spinal deformity were included. The patients were divided into two groups: the PJK group (n = 7) and the nonPJK group (n = 14). Patients who experienced PJK within half a year of surgery were included in the PJK group. Pelvic incidence (PI), lumbar lordosis (LL), pelvic tilt (PT), thoracic kyphosis (TK), thoracic compensation (TK compensation), sagittal vertical axis (SVA), T10–L2 angle, and T1 pelvic angle (TPA) were measured before and after surgery.

    Results: No difference was found between the two groups in terms of age and sex at the time of surgery. The indices that were significantly different between the two groups were preoperative PT, PI minus LL, TK, TPA, TK compensation, and postoperative T10–L2 angle. No significant differences were found in postoperative LL, PI minus LL, PT, TK, TPA, or SVA.

    Conclusions: Preoperative X-ray indices, including preoperative TPA, TK compensation, TK, PT, and PI–LL, determined the risk of PJK in fusions from the sacrum to L1 or L2. Appropriate patient selection is crucial for the success of this surgery.

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  • Hiromi Kumamaru, Keiichiro Iida, Takeyuki Saito, Shingo Yoshizaki, Yas ...
    Article ID: 2021-0181
    Published: 2021
    Advance online publication: December 27, 2021
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    Introduction

    Facet joints are anatomical structures that are known to be crucial for determining spinal biomechanical motion; however, the potential relationship between facet orientation and the development of cervical spondylolisthesis remains unclear. Thus, in this study, we aimed to explore the relationship between facet orientation and cervical spondylolisthesis as well as myelopathy.

    Methods

    Facet orientation in the cervical spine was investigated using computed tomography in 103 patients with cervical myelopathy, and facet inclination was measured on axial, coronal, and sagittal reconstructed images. Patients were divided into anterolisthesis, retrolisthesis, and no spondylolisthesis groups at each intervertebral level (C2/3–C6/7 levels).

    Results

    Facet joints in the anterolisthesis and retrolisthesis groups tended to slope posterolaterally and downward laterally compared with those in the no spondylolisthesis group at C3/4, C4/5, and C5/6 levels (P < 0.001).

    Conclusions

    The posterolaterally oriented and laterally downward sloping facet at C3/4 and C4/5 levels may be a risk factor for the development of cervical spondylolisthesis as well as symptomatic myelopathy.

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  • Masashi Uehara, Shota Ikegami, Takashi Takizawa, Hiroki Oba, Noriaki Y ...
    Article ID: 2021-0183
    Published: 2021
    Advance online publication: December 27, 2021
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    Background: In elderly patients with cervical spinal cord injury, comorbidities such as cardiovascular and cerebrovascular diseases are common, with frequent administration of antiplatelet/anticoagulant (APAC) drugs. Such patients may bleed easily or unexpectedly during surgery despite prior withdrawal of APAC medication. Few reports have examined the precise relationship between intraoperative blood loss and history of APAC use regarding surgery for cervical spine injury in the elderly.The presentmulticenter database survey aimed to answer the question of whether the use of APAC drugs affected the amount of intraoperative blood loss in elderly patients with cervical spinal cord trauma.

    Methods: The case histories of 1512 patients with cervical spine injury at 33 institutes were retrospectively reviewed. After excluding cases without spinal surgery or known blood loss volume, 797 patients were enrolled. Blood volume loss was the outcome of interest. We calculated propensity scores using the inverse probability of treatment weighting (IPTW) method. As an alternative sensitivity analysis, linear mixed model analyses were conducted as well.

    Results: Of the 776 patients (mean age: 75.1 ± 6.4 years) eligible for IPTW calculation, 157 (20.2%) were taking APAC medications before the injury. After weighting, mean estimated blood loss was 204 mL for non-APAC patients and 215 mL for APAC patients. APAC use in elderly patients was not significantly associated with surgical blood loss according to the IPTW method with propensity scoring or linear mixed model analyses. Thus, it appeared possible to perform surgery expecting comparable blood loss in APAC and non-APAC cases.

    Conclusions: This multicenter study revealed no significant increase in surgical blood loss in elderly patients with cervical trauma taking APAC drugs. Surgeons may be able to prioritize patient background, complications, and preexisting conditions over APAC use before injury when examining the surgical indications for cervical spine trauma in the elderly.

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  • Satoru Demura, Eiichi Hinoi, Noriaki Kawakami, Makoto Handa, Noriaki Y ...
    Article ID: 2021-0189
    Published: 2021
    Advance online publication: December 27, 2021
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    Introduction. Amino acid transporters are transmembrane proteins that are known to mediate the transfer of amino acids. As one of the amino acid transporters, LAT1, which is encoded by Slc7a5, mediates the cellular uptake of the essential amino acids. Recently, most studies have focused on examining the relationship between LAT1 and skeletal formation in terms of development. However, little is known regarding the clinical features of LAT1 in the cartilage, which might result in the development of skeletal deformities such as scoliosis. Thus, the aim of this study was to investigate the expression of L-type amino acid transporter 1 (LAT1) and its solute carrier transporter 7a5 (Slc7a5) in patients with pediatric scoliosis and to compare with the relationship between LAT1 and Slc7a5 expression and their clinical features.

    Methods. We have prospectively recruited 56 patients who underwent corrective spinal fusion for scoliosis. The patients comprised 40 girls and 16 boys, with a mean age of 13.1 years at the time of surgery. There were 34 idiopathic scoliosis (IS) patients, whereas 22 were congenital scoliosis (CS) patients. During the surgery, an epiphyseal part of the spinous process at apical vertebra was harvested; then, LAT1 and Slc7a5 expressions in the cartilage were evaluated.

    Results. As per our findings, LAT1 expression was observed in the cartilage in 60.7% (34 out of 56) of the patients. LAT1 expression in IS patients was 76%, which were statistically higher compared to 36% in CS patients. When compared with LAT1 expression, no statistical difference was noted in terms of age, gender, body mass index (BMI), Cobb angle, and Risser grade. Meanwhile, the mean Slc7a5 expression in IS patients was determined to be significantly higher than that in CS patients. No significant correlation was observed between Slc7a5 expression and age, BMI, and Cobb angle.

    Conclusions. LAT1 and Slc7a5 expression in IS and CS patients showed significant differences. These expressions were found to be not correlated with age, stature, and severity of the deformity.

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  • Masaaki Machino, Hiroaki Nakashima, Keigo Ito, Mikito Tsushima, Kei An ...
    Article ID: 2021-0187
    Published: 2021
    Advance online publication: December 14, 2021
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION
    Supplementary material

    Introduction: Intervertebral disk degeneration is a universal and natural process. However, no reports have summarized anatomical age-related intervertebral disk height and disk degenerative changes in the thoracolumbar spine or examined sex-specific differences. This study aimed to establish age-related changes and gender-specific differences of intervertebral disk height and disk degeneration of the thoracolumbar spine in a large cohort of relatively healthy subjects and also to evaluate the relationship between the degree of thoracolumbar disk height and disk degeneration.

    Methods: Six hundred and twenty-seven relatively healthy subjects (307 males and 320 females; average age, 49.6 ± 16.5 years) were enrolled. We included at least 50 males and 50 females in each decade of life between the 20s and the 70s. We measured intervertebral disk height from T10/T11 to L5/S1, vertebral body height from T10 to S1 on lateral neutral radiographs. Lumbar disk degeneration was defined according to the Pfirrmann classification in sagittal plane magnetic resonance imaging.

    Results: Age-related decreases in intervertebral disk height were most prominent at L4/L5 in middle-aged and elderly individuals of both sexes. The grade of disk degeneration significantly increased with age in both genders at every level. Mild disk degeneration was observed even in the 20s. The disk degeneration occurred around the L4/L5 level. Although grade V disk degeneration was not identified for males in the 20s and the 30s, it appeared after the 40s and then increased further with age. The intervertebral disk height at the lower lumbar disks decreased with a progression in the disk degeneration grade in both genders.

    Conclusions: This large-scale cross-sectional analysis of the thoracolumbar spine in relatively healthy subjects demonstrated that lumbar disk height narrowing progresses with age and is correlated with the progression of disk degeneration.

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  • Yuki Taniguchi, Yoshitaka Matsubayashi, Toshiyuki Ikeda, So Kato, Toru ...
    Article ID: 2021-0190
    Published: 2021
    Advance online publication: December 14, 2021
    JOURNAL OPEN ACCESS ADVANCE PUBLICATION

    Background: Fibrin glue is widely used in spine surgery. Nevertheless, no report has demonstrated the feasibility of completely autologous fibrin glue (CAFG) in spine surgery. This study aims to investigate the safety, efficacy, and effect of bone fusion of CAFG on spine surgery.

    Methods: We retrospectively extracted data of patients who underwent primary spine surgery with preoperatively prepared CAFG. Primary outcomes were the incidence of wound-related unplanned reoperations within 90 days following primary surgery and the occurrence of reoperation for the management of cerebrospinal fluid (CSF) leakage in patients who had been treated with CAFG used as dural sealants. The effect of CAFG on bone fusion was also assessed by detecting implant failure at one year postoperatively in patients aged 25 years or less undergoing primary fusion for idiopathic scoliosis.

    Results: We identified 131 eligible patients (47 males and 84 females) with a mean age of 32.3 years. CAFG was used most frequently as an adhesive for fixation of graft bone (110 patients), followed by as a dural sealant for CSF leakage in 17 patients, and as a local hemostatic agent in four patients. Wound-related reoperations were identified in four patients (3.1%), which included three for surgical site infection, and one for postoperative epidural hematoma. There was no reoperation required for the management of CSF leakage among 17 patients with dural incision or incidental durotomy. Compared with the control cohort, the use of CAFG was not associated with early wound-related reoperations or implant failure in patients with spinal deformity.

    Conclusions: We demonstrated the clinical feasibility of CAFG in spine surgery. The use of CAFG was not associated with the incidence of reoperations for wound-related complications. CAFG worked effectively as a dural sealant for preventing CSF leakage. CAFG had no beneficial or adverse effect on spinal bone fusion.

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