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Background: Although posterior decompression with fusion (PDF) are effective for treating thoracic myelopathy, surgical treatment has a high risk of various complications. There is currently no information available on the perioperative complications in thoracic ossification of the longitudinal ligament (T-OPLL) and thoracic ossification of the ligamentum flavum (T-OLF). We evaluate the perioperative complication rate and cost between T-OPLL and T-OLF for patients underwent PDF. Methods: Patients undergoing PDF for T-OPLL and T-OLF from 2012 to 2018 were detected in Japanese nationwide inpatient database. One-to-one propensity score matching between T-OPLL and T-OLF was performed based on patient characteristics and preoperative comorbidities. We examined systemic and local complication rate, reoperation rate, length of hospital stays, costs, discharge destination, and mortality after matching. Results: In a total of 2,660 patients, 828 pairs of T-OPLL and T-OLF patients were included after matching. The incidence of systemic complications did not differ significantly between the T-OPLL and OLF groups. However, local complications were more frequently occurred in T-OPLL than in T-OLF groups (11.4% vs. 7.7% P = 0.012). Transfusion rates was also significantly higher in the T-OPLL group (14.1% vs. 9.4%, P = 0.003). T-OPLL group had longer hospital stay (42.2 days vs. 36.2 days, P = 0.004) and higher medical costs (USD 32,805 vs. USD 25,134, P < 0.001). In both T-OPLL and T-OLF, the occurrence of perioperative complications led to longer hospital stay and higher medical costs. While fewer patients in T-OPLL were discharged home (51.6% vs. 65.1%, P < 0.001), patients were transferred to other hospitals more frequently (47.5% vs. 33.5%, P = 0.001). Conclusion: This research identified the perioperative complications of T-OPLL and T-OLF in PDF using a large national database, which revealed that the incidence of local complications was higher in the T-OPLL patients. Perioperative complications resulted in longer hospital stays and higher medical costs. [ABSTRACT FROM AUTHOR]

Background: Both cancer diagnosis/treatment modality and surgical technique for the spine have been developed recently. Nationwide trends in the surgical treatment for metastatic spinal tumors have not been reported in the last decades. This study aimed to examine recent trends in the surgical treatment for spinal metastasis and in-hospital patient outcomes using nationwide administrative hospital discharge data. Methods: The Diagnosis Procedure Combination database from 2012 to 2020 was used to extract data from patients who underwent surgical procedures for spinal metastasis with the number of non-metastatic spinal surgery at the institutions that have performed metastatic spine surgeries at least one case in the same year. Trends in the surgical treatment for spinal metastasis, patients' demographics, and in-hospital mortality/outcomes were investigated. Results: This study analyzed 10,321 eligible patients with spinal metastasis. The surgical treatment for spinal metastasis increased 1.68 times from 2012 to 2020, especially in fusion surgery, whereas the proportion of metastatic spinal surgery retained with a slight increase in the 2%s. Distributions of the primary site did not change, whereas age was getting older. In-hospital mortality and length of stay decreased over time (9.9–6.8%, p < 0.001; 37–30 days, p < 0.001). Postoperative complication and unfavorable ambulatory retained stable and slightly decreased, respectively. Conclusion: During the last decade, surgical treatment for spinal metastasis, especially fusion surgery, has increased in Japan. In-hospital mortality and length of stay decreased. Recent advances in cancer treatment and surgical techniques might influence this trend. [ABSTRACT FROM AUTHOR]

Study Design.: A prospective multicenter study. Objective.: The objective of this study is to compare the surgical outcomes of anterior and posterior fusion surgeries in patients with K-line (−) cervical ossification of the posterior longitudinal ligament (OPLL). Summary of Background Data.: Although laminoplasty is effective for patients with K-line (+) OPLL, fusion surgery is recommended for those with K-line (−) OPLL. However, whether the anterior or posterior approach is preferable for this pathology has not been effectively determined. Materials and Methods.: A total of 478 patients with myelopathy due to cervical OPLL from 28 institutions were prospectively registered from 2014 to 2017 and followed up for two years. Of the 478 patients, 45 and 46 with K-line (−) underwent anterior and posterior fusion surgeries, respectively. After adjusting for confounders in baseline characteristics using a propensity score-matched analysis, 54 patients in both the anterior and posterior groups (27 patients each) were evaluated. Clinical outcomes were assessed using the cervical Japanese Orthopaedic Association and the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire. Results.: Both approaches showed comparable neurological and functional recovery. The cervical range of motion was significantly restricted in the posterior group because of the large number of fused vertebrae compared with the anterior group. The incidence of surgical complications was comparable between the cohorts, but the posterior group demonstrated a higher frequency of segmental motor paralysis, whereas the anterior group more frequently reported postoperative dysphagia. Conclusions.: Clinical improvement was comparable between anterior and posterior fusion surgeries for patients with K-line (−) OPLL. The ideal surgical approach should be informed based on the balance between the surgeon's technical preference and the risk of complications. [ABSTRACT FROM AUTHOR]

Factors related to postoperative mechanical failure after long fusion with lower instrumented vertebra (LIV) at L5 have not been well investigated. Elucidating such factors may allow us to perform alternatives to spinopelvic fusion for adult spinal deformity (ASD) cases. We investigated the incidence and risk factors of LIV failure in patients with ASD who underwent surgical treatment of long corrective fusion until the L5 vertebrae. Between 2009 and 2018, 52 patients who underwent corrective fusions to L5 were followed-up for at least one-year. We evaluated the associated patient factors for LIV failure which include loosening of the pedicle screw of LIV, fracture of LIV, distal junctional kyphosis (DJK). The mean age of the participants was 71.2 ± 7.59 (range, 44–84). LIV failure occurred in 20 patients (38.5%), and 6 patients (11.5%) underwent secondary surgery for caudal segments. The mean pelvic incidence (PI) was 52.5 ± 9.8 in the failure group versus 45.3 ± 11.4 in non-failure group (P = 0.02) and pelvic tilt (PT) was 39.1 ± 9.0 versus 32.4 ± 13.0. There were no significant differences in sex, age, body mass index, number of levels fused, and other radiographic data. Logistic regression analysis that included T1 pelvic angle, PT, PI - postoperative LL and PI also identified PI as the only significant determinant of LIV failure (OR = 1.07, P = 0.034). Receiver operating characteristic analysis demonstrated that a PI over 50.0° was associated with LIV failure (sensitivity 63%, specificity 70%, AUC 0.694). LIV failure was frequently observed after long corrective fusion for patients with ASD. High PI was found to be a significant risk factor for the LIV failure. [ABSTRACT FROM AUTHOR]

To evaluate the radiological differences between diffuse idiopathic skeletal hyperostosis (DISH) and ankylosing spondylitis (AS) using whole spine computed tomography (CT), including the spine and sacroiliac joint (SIJ). The ossification and bridging of spinal ligament and fusion of the facet joint and SIJ were evaluated in 111 patients who were diagnosed with DISH and 27 patients with AS on the whole spine CT. The number of anterior bridging and shape of bridging (candle-wax-type/ smooth-type) were also evaluated. We further evaluated patients with DISH and AS by matching their age and sex. Complete SIJ fusion was more common in AS, whereas anterior and posterior bony bridging around SIJ was more common in DISH. However, 63% of patients with DISH had a partial or complete fusion. In spinal anterior bony bridging, the majority of patients with AS had the smooth-type, whereas those with DISH had the candle-wax-type. However, some of the patients with DISH (11%) had smooth-type. Intervertebral facet joint fusion is more common in AS. The number of anterior spinal bony bridging was greater in AS than in DISH, especially in the lumbar spine. These results are useful in differentiating DISH from AS and should therefore be considered when making a diagnosis. [ABSTRACT FROM AUTHOR]

Study Design.: A prospective comparative study. Objective.: To investigate the benefits of postoperative application of lumbosacral orthosis after single-level discectomy for lumbar disk herniation (LDH). Summary of Background Data.: Although many surgeons use postoperative lumbosacral orthosis for patients with LDH, there is no clear evidence to support or deny its effectiveness. Materials and Methods.: Ninety-nine consecutive patients who underwent the microscopic discectomy were included. They were divided into two groups: orthosis group and nonorthosis group, before surgery. The recurrence rate and reoperation rate were compared between the two groups at four-week, six-month, and one-year follow-up. Japanese Orthopaedic Association Score for lumbar spine (L-JOA score) at two-week and one-year follow-up, lower extremities and low back pain's visual analog scale (VAS) and Oswestry Disability Index (ODI) at six-month and one-year follow-up were compared. Results.: Forty-two patients in the orthosis group and 39 patients in the nonorthosis group were followed up for at least one-year after surgery. Recurrence occurred in three patients (7.1%) in the orthosis group and six (15.4%) in the nonorthosis group within one-year. Two patients (4.8%) in the orthosis group and two patients (5.1%) in the nonorthosis group underwent reoperation. There were no significant intergroup differences in the recurrence rate and in the reoperation rate. No significant difference was also observed between the two groups in L-JOA score, ODI, VAS of low back pain, and leg pain at one-year after surgery. Furthermore, at any other follow-up period, no significant differences were observed between the two groups in recurrence rate, reoperation rate, L-JOA score, VAS of low back/leg pain, or ODI. Conclusions.: The use of a postoperative orthosis did not reduce recurrence or reoperation rates, nor did it improve postoperative clinical symptoms. The routine use of an orthosis may not be necessary after single-level lumbar discectomy. [ABSTRACT FROM AUTHOR]

The ideal surgical strategy for cervical ossification of the posterior longitudinal ligament (OPLL) remains controversial due to the lack of high-quality evidence. Herein, we prospectively investigated the surgical outcomes of anterior cervical decompression with fusion (ADF) and laminoplasty (LAMP) with cervical OPLL. Three hundred patients were included in this study (ADF: n = 89; LAMP: n = 211 patients), and propensity score matching yielded 67 pairs of patients with ADF and LAMP, in which clinical outcomes were compared. Crude analysis revealed that the ADF group showed greater neurological recovery in cervical Japanese Orthopedic Association scores at two years, compared with that in the LAMP group (53.1% vs. 44.3%, p = 0.037). The ratio of minimum clinically important difference (MCID) success was significantly greater in the ADF group (59.6% vs. 43.6%, p = 0.016). Multivariate analysis showed that the factors affecting MCID success were age, body mass index, duration of symptoms, and choice of ADF. In the 1:1 matched analysis, neurological improvement was more favorable in the ADF group (57.2%) compared to the LAMP group (46.8%) at two years (p = 0.049). However, perioperative complications, such as dysphagia and graft-related complications, were more common in the ADF group. [ABSTRACT FROM AUTHOR]

Background: Few studies have directly compared anterior and posterior surgical approaches in cervical spondylotic myelopathy (CSM) patients with short-segment disease. We aimed to examine and compare surgical outcomes of anterior cervical discectomy with fusion (ACDF) and selective laminoplasty (S-LAMP) in CSM patients with 1- or 2-level disease.Methods: Forty-six patients, who received surgeries for CSM, were prospectively investigated; 24 underwent ACDF and 22 underwent S-LAMP. Average follow-up was 3.5 years. The following pre- and postoperative radiographic measurements were recorded: (1) C2-7 angle, (2) local angle (lordotic Cobb angle at operative level), (3) cervical sagittal vertical axis (SVA) (center of gravity of the head-C7 SVA), and (4) C7 slope. Outcomes were evaluated using the Japanese Orthopedic Association scoring system for cervical myelopathy (C-JOA score), neck pain visual analog scale, and neck disability index (NDI).Results: There were no significant differences in patient demographics between the two groups. Postoperatively, C2-7 angle, local angle, cervical SVA, C7 slope, C-JOA score, and neck pain and NDI scores were not significantly different between the two groups; however, the recovery rate of the C-JOA score was superior in the ACDF group (57.5%) compared to the S-LAMP group (42.1%). The recovery rate of the C-JOA score in the local lordosis subgroup (local angle ≥ 0°) showed no significant difference between the two surgical groups. However, in the local kyphosis subgroup (local angle < 0°), C-JOA score recovery rate was worse after S-LAMP (20.4%) than ACDF (57.9%); local angle also worsened postoperatively after S-LAMP.Conclusions: In patients with local lordosis at the segments of cervical spondylosis and spinal cord compression, S-LAMP showed equivalent surgical outcomes (neurological recovery, neck pain and NDI scores, and cervical alignment) to ACDF. However, in patients with local kyphosis, S-LAMP worsened the kyphosis and resulted in worse neurological recovery. [ABSTRACT FROM AUTHOR]

Background: Surgical procedures for cervical myelopathy caused by ossification of the posterior longitudinal ligament (OPLL) are often chosen based on OPLL size and cervical spine alignment. Recently, cervical sagittal alignment based on sagittal vertical axis (SVA) has received increased attention as an important determinant of radiological and clinical outcomes after surgery. This study aimed to investigate the impact of SVA-based cervical sagittal alignment on surgical treatment for cervical OPLL by reviewing a previous retrospective cohort in which its concept was not taken into account in the surgical procedure choices.Methods: We reviewed a total of 96 consecutive patients who underwent surgery for cervical myelopathy caused by OPLL from 2008 to 2014. We performed anterior decompression with fusion (ADF) or posterior decompression with fusion (PDF) on patients with massive OPLL or kyphotic alignment, and we performed laminoplasty (LAMP) on patients without massive OPLL or kyphotic alignment. CSVA (center of gravity of the head - C7 SVA), CL (C2-7 lordotic angle) and C7 slope were measured in cervical X-ray at standing position. Clinical results were evaluated using C-JOA score. We divided patients into two subgroups based on the preoperative CSVA: the Low-CSVA (CSVA <40 mm) and High-CSVA (CSVA ≥40 mm) subgroups.Results: In the Low-CSVA subgroup, none of the three operations had an effect on the CL. In contrast, in the High-CSVA subgroup, while ADF and PDF had no effect on the CL, LAMP worsened the CL postoperatively. The recovery rates of the C-JOA scores in the Low-CSVA subgroup showed no significant differences among the three operations; however in the High-CSVA subgroup, LAMP resulted in worse recovery rate of the C-JOA score than ADF or PDF.Conclusions: LAMP is not suitable for patients with cervical myelopathy caused by OPLL who have high CSVA alignment, even in cases without massive OPLL or kyphotic alignment. [ABSTRACT FROM AUTHOR]

Study Design: A prospective multicenter study.Objective: This study aims to evaluate patient-reported outcomes using the Japanese Orthopedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ) and clarify clinical factors that affect the therapeutic effects for patients with cervical ossification of the posterior longitudinal ligament (OPLL).Summary Of Background Data: Although previous studies identified factors that affected the surgical outcomes, their assessment was mainly based on the Japanese Orthopedic Association score, which only includes neurological function. Investigating this pathology through multiple functions and quality of life (QOL) is pivotal to understanding the comprehensive clinical pictures of the cervical OPLL and its therapeutic outcomes.Materials and Methods: This study was performed by the Japanese Multicenter Research Organization for Ossification of the Spinal Ligament. A total of 478 patients with myelopathy caused by cervical OPLL from 28 institutions were prospectively registered from 2014 to 2017 and followed up for 2 years. Of the patients, 168 received laminoplasties and fully completed questionnaires. Demographic information, imaging findings, and clinical outcomes were collected. Patients were grouped according to effective or ineffective surgical outcomes as defined by the JOACMEQ using logistic regression analyses.Results: Laminoplasty resulted in functional improvement in the cervical spine and upper extremity around 40% of the patients, while QOL showed only 21.4% ( P <0.01). Multivariable analyses revealed that younger age and a postoperative decrease in arm or hand pain were correlated with significantly improved function of the upper extremities. A reduction in lower limb pain favorably affected the postoperative lower extremity function. A postoperative reduction in upper extremity pain enhanced the QOL recovery.Conclusions: Surgeons should recognize the diversity of surgical outcomes after laminoplasty and understand the necessity of pain management even after the surgery to enhance bodily functions and QOL in patients with cervical OPLL. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to clarify the clinical features of ossification of the posterior longitudinal ligament (OPLL) and extreme ossification at multiple sites. Methods: This prospective study involved patients with a diagnosis of cervical OPLL at 16 institutions in Japan. Patient-reported outcome measures, including responses on the Japanese Orthopaedic Association (JOA) Cervical Myelopathy Evaluation Questionnaire (JOA-CMEQ), JOA Back Pain Evaluation Questionnaire (JOA-BPEQ), and visual analog scale pain score, were collected to investigate clinical status. In each patient, the sum of the levels at which OPLL was located (OP index) was evaluated on whole-spine computed tomography, along with ossification of other spinal ligaments including the anterior longitudinal ligament (OALL), ligament flavum (OLF), supra- and intraspinous ligaments (SSL), and diffuse idiopathic skeletal hyperostosis (DISH). The distribution of OP index values in the study population was investigated, and the clinical and radiologic characteristics of patients in the top 10% were assessed. Results: In total, 236 patients (163 male, 73 female; mean age 63.5 years) were enrolled. Twenty-five patients with OP index ≥ 17 were categorized into a high OP index group and the remainder into a moderate/low OP index group. There were significantly more women in the high OP index group. Patients in the high OP index group also had significantly poorer scores for lower extremity function and quality of life on the JOA-CMEQ and in each domain but not for body pain on the JOA-BPEQ compared with those in the moderate/low OP index group. Patients in the high OP index group had more OALL in the cervical spine and more OLF and SSL in the thoracic spine. The prevalence of DISH was also significantly higher in the high OP index group. In the high OP index group, interestingly, OPLL was likely to be present adjacent to DISH in the cervicothoracic and thoracolumbar spine, especially in men, and often coexisted with DISH in the thoracic spine in women. Conclusion: This prospective cohort registry study is the first to demonstrate the clinical and radiologic features of patients with OPLL and a high OP index. In this study, patients with a high OP index had poorer physical function in the lumbar spine and lower extremities and were also predisposed to extreme ossification of spinal ligaments other than the OPLL. [ABSTRACT FROM AUTHOR]

Background: Ossification of the posterior longitudinal ligament of the spine (OPLL) is characterized by heterotopic bone formation in the posterior longitudinal ligament of the spine. Although the patients with OPLL are more common in the 60s and 70s, we know that there are markedly young patients (e.g., early 40s). However, to the best of our knowledge, there is few reports characterize young patients with cervical OPLL in terms of the imaging features, subjective symptoms, and ADL problems.Methods: This is the multicenter cross-sectional study. Two hundred and thirty-seven Japanese symptomatic patients with cervical OPLL confirmed by standard X-rays collected from 16 institutions belonging to the Japanese Multicenter Research Organization for Ossification of the Spinal Ligament formed by the Japanese Ministry of Health, Labor and Welfare were recruited. Whole spine CT data as well as demographic data such as age, gender, patients-based evaluations, and the 36-item Short Form Health Survey (SF-36) were evaluated.Results: Young group (≦ 45 years old) consisted of 23 patients (8 females and 15 males), accounting for 9.7% of the total. Their characteristics were high body mass index (BMI), significant involvement of trauma in the onset and deterioration of symptoms, and the predominance of thoracic OPLL. The patient-based evaluations did not show a significant difference between the young and non-young groups, or between the genders in the young group except for bodily pain (BP) of SF-36. Female patients in young group had significantly lower BP score of SF-36 than that of male in young group.Conclusions: Characteristics of young patients with cervical OPLL were high BMI, significant involvement of trauma in the onset and deterioration of symptoms, lower BP score of SF-36 in female, and the predominance of thoracic OPLL. [ABSTRACT FROM AUTHOR]

For ossification of the posterior longitudinal ligament (OPLL) and cervical spondylotic myelopathy (CSM), anterior decompression with fusion (ADF) can accurately achieve spinal decompression. However, the difference in perioperative complications in ADF between OPLL and CSM is poorly described. This study aimed to investigate the perioperative complication rates of patients with degenerative cervical myelopathy undergoing ADF, represented by OPLL and CSM, using a large national inpatient database. In the OPLL and CSM groups, postoperative complication (systemic and local) rates, reoperation rates, medical costs during hospitalization, and mortality after propensity score matching were compared. After matching, 1197 matched pairs were made. The incidence of total systemic complications was similar between both groups (OPLL, 12.4%; CSM, 12.2%). In the OPLL group, more perioperative local complications (cerebrospinal fluid leakage: CSFL, [OPLL, 2.7%; CSM, 0.3%] and surgical site infection: SSI [OPLL, 2.1%; CSM, 0.9%]) were detected, and the hospitalization cost was approximately $3200 higher than that in the CSM group. Moreover, medical costs were significantly higher in patients who experienced complications in both OPLL and CSM. The frequency of perioperative complications of OPLL and CSM in ADF was detailed using large real-world data. Compared to CSM, OPLL had more perioperative complications such as CSFL and SSI, and higher medical costs. Regardless of the disease, medical costs were significantly increased when perioperative complications occurred. [ABSTRACT FROM AUTHOR]

Background Context: Its rare prevalence and subtle radiological changes often lead to difficulties in diagnosing cervical ossification of the posterior longitudinal ligament (OPLL) on plain radiographs. However, OPLL progression may lead to trauma-induced spinal cord injury, resulting in severe paralysis. To address the difficulties in diagnosis, a deep learning approach using a convolutional neural network (CNN) was applied.Purpose: The aim of our research was to evaluate the performance of a CNN model for diagnosing cervical OPLL.Study Design and Setting: Diagnostic image study.Patient Sample: This study included 50 patients with cervical OPLL, and 50 control patients with plain radiographs.Outcome Measures: For the CNN model performance evaluation, we calculated the area under the receiver operating characteristic curve (AUC). We also compared the sensitivity, specificity, and accuracy of the diagnosis by the CNN with those of general orthopedic surgeons and spine specialists.Methods: Computed tomography was used as the gold standard for diagnosis. Radiographs of the cervical spine in neutral, flexion, and extension positions were used for training and validation of the CNN model. We used the deep learning PyTorch framework to construct the CNN architecture.Results: The accuracy of the CNN model was 90% (18/20), with a sensitivity and specificity of 80% and 100%, respectively. In contrast, the mean accuracy of orthopedic surgeons was 70%, with a sensitivity and specificity of 73% (SD: 0.12) and 67% (SD: 0.17), respectively. The mean accuracy of the spine surgeons was 75%, with a sensitivity and specificity of 80% (SD: 0.08) and 70% (SD: 0.08), respectively. The AUC of the CNN model based on the radiographs was 0.924.Conclusions: The CNN model had successful diagnostic accuracy and sufficient specificity in the diagnosis of OPLL. [ABSTRACT FROM AUTHOR]

Positive association between ossification of the posterior longitudinal ligament of the spine (OPLL) and obesity is widely recognized; however, few studies focused on the effects of obesity on treatment of cervical OPLL. The effects of obesity on surgical treatment of cervical OPLL were investigated by a Japanese nationwide, prospective study. Overall, 478 patients with cervical myelopathy due to OPLL were prospectively enrolled. To clarify the effects of obesity on the surgical treatment for cervical OPLL, patients were stratified into two groups, non-obese (< BMI 30.0 kg/m2) and obese (≥ BMI 30.0 kg/m2) groups. The mean age of the obese group was significantly younger than that of non-obese group. There were no significant differences between the two groups in other demographic information, medical history, and clinical and radiographical findings. Alternatively, the obese group had a significantly higher rate of surgical site infection (SSI) than that of non-obese group. Approach-specific analyses revealed that the SSI was significantly higher in the obese group than in the non-obese group. A logistic regression analysis revealed that age, BMI, and duration of symptoms were significant factors affecting the postoperative minimum clinically important difference success. The result of this study provides useful information for future cervical OPLL treatment. [ABSTRACT FROM AUTHOR]

Background: Thoracic ossification of the posterior longitudinal ligament (T-OPLL) is a rare disease, which can cause spinal cord compression leading to various neurological symptoms. There are limited treatment options for T-OPLL, surgery is generally considered the only effective treatment. However, few studies have investigated surgical complications in patients with T-OPLL, and there are no data regarding surgical risks in anterior decompression with fusion (ADF) when compared with posterior decompression with fusion (PDF) for T-OPLL.Methods: Patients who were diagnosed as T-OPLL and underwent ADF via the anterior approach and PDF via the posterior approach from April 1, 2012 to March 31, 2018, were extracted from the Diagnosis Procedure Combination (DPC) database. We analyzed perioperative systemic and local complication rates after ADF and PDF and compared them using propensity score matching (PSM) method. In each of the two groups, we investigated the details of length of stay, costs, mortality, and discharge destination.Results: In total 1344 patients (ADF: 88 patients, PDF: 1256 patients), 176 patients were investigated after PSM (88 pairs). While the incidence of overall systemic complication was significantly higher in the ADF group (ADF/PDF: 25.0%/8.0%, P = 0.002), there was no significant difference in the overall local complication rate (15.9%/19.3%, P = 0.55). Specifically, respiratory complications were more frequently observed in the ADF group (9.1%/0%, P = 0.004), however, other systemic and local complications did not differ significantly between the two groups. The length of stay was 1.7 times longer (P < 0.001) and the medical costs were 1.4 times higher (P < 0.001) in patients with perioperative complications, compared to those without perioperative complications.Conclusion: We demonstrated the perioperative complications of ADF and PDF in patients with T-OPLL using a large national database. ADF showed a higher incidence of respiratory complications. Development of perioperative complications was associated with longer hospital stay and higher medical costs. [ABSTRACT FROM AUTHOR]

Background: Several studies have reported that overweightness and obesity are associated with higher complication rates in lumbar spine surgery. However, little is known about the effect of obesity on postoperative complications in adult spinal deformity (ASD) surgery, especially in the elderly. This study aimed to examine the effect of body mass index (BMI) on surgical outcomes and postoperative complications in elderly ASD patients undergoing surgical correction in Japan.Methods: We conducted a retrospective, multicenter, observational study of 234 consecutive patients diagnosed with ASD who underwent corrective surgery. Patients were divided into two groups according to BMI, BMI <25 (153 patients, mean age 71.9 years) and BMI ≥ 25 (overweight/obese, 81 patients, mean age 73.3 years). Radiographic results and perioperative complications were compared between the two groups.Results: Surgical complications occurred in approximately 20% of patients in each group; complications did not significantly differ between the two groups. A greater proportion of patients in the BMI ≥ 25 group experienced mechanical failure and DJK, although the difference was not significant. Preoperative mean lumbar lordosis (LL), pelvic incidence (PI) minus LL, sacral slope (SS) and sagittal vertical axis (SVA) were similar in the BMI < 25 and BMI ≥ 25 groups. However, the BMI ≥25 group had lower mean LL (p = 0.015) and higher PI minus LL (p = 0.09) postoperatively. The BMI ≥25 groups also had significantly smaller LL (p = 0.026), smaller SS (p = 0.049) and higher SVA (p = 0.041) at the final follow-up, compared to the BMI < 25 group.Conclusions: In the present study, no difference in medical or surgical complications after ASD surgery was found between overweight/obese patients (BMI ≥ 25) and those with BMI < 25. However, correction of LL and SVA was smaller in patients with overweight/obese patients. [ABSTRACT FROM AUTHOR]

Study Design: A prospective multicenter study.Objective: To evaluate and compare the surgical outcomes after open-door (OD) and double-door (DD) laminoplasties in subjects with cervical ossification of the posterior longitudinal ligament (OPLL).Summary Of Background Data: Although previous studies compared clinical results after OD and DD laminoplasties, they were performed at a single institution with a relatively small sample size targeting mixed pathologies, including cervical spondylotic myelopathy.Methods: This study was performed by the Japanese Multicenter Research Organization for Ossification of the Spinal Ligament. A total of 478 patients with myelopathy caused by cervical OPLL from 28 institutions were prospectively registered from 2014 to 2017 and followed up for 2 years. Of these, 41 and 164 patients received OD and DD laminoplasties, respectively. Demographic information, medical history, and imaging findings were collected. Clinical outcomes were assessed using the cervical Japanese Orthopaedic Association, Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire, and visual analog scale scores.Results: Age, sex, symptom duration, and comorbidities were not significantly different between the groups. Segmental ossification was the most frequent in both the groups. No significant differences in K-line type, canal occupying ratio, C2 to C7 angles, and range of motion were found. Both the procedures reduced the cervical range of motion postoperatively. A comparable frequency of perioperative complications was observed between the groups. The cervical Japanese Orthopaedic Association scores showed a similar improvement at 2 years postopera- tively. The reduction in visual analog scale score for neck pain was favorable in the OD group (P = 0.02), while other pain assessments did not show any significant differences between the groups. The functional outcomes assessed using the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire presented equivalent effective rates.Conclusion: The results demonstrated almost comparable surgical outcomes between OD and DD laminoplasties. Lamino- plasty is a valuable technique as a therapeutic option for cervical OPLL.Level of Evidence: 2. [ABSTRACT FROM AUTHOR]

Study Design: A prospective multicenter study.Objective: This study aims to investigate the postoperative complications of anterior decompression with fusion (ADF) for the treatment of cervical ossification of the posterior longitudinal ligament (OPLL).Summary Of Background Data: Surgical treatment for cervical OPLL has a high risk of various complications. ADF is reported to be effective for cervical OPLL, especially for massive OPLL. However, few studies have focused on the surgical complications of ADF.Methods: We prospectively included 102 patients undergoing ADF for severe cervical OPLL with average canal occupying ratio of 49.8%. We evaluated systemic and local complications, neurological complications, and risk factors related to the postoperative complications.Results: Frequently observed complications included graft/ implant complications (18.6%), neurological complications (11.8%), and cerebrospinal fluid leak (11.8%). Motor palsy involving only the upper extremity was found in nine patients (8.8%), and other motor palsies involving the lower extremities were found in three patients (2.9%). None of the preoperative factors were significantly associated with the occurrence of neurological palsies, whereas the number of operated levels was a significant factor related to the postoperative graft/implant complications (P = 0.003; odds ratio, 2.112). The incidence of graft/implant complications and related reoperation increased as the number of operated levels increased (especially four levels or more). Most motor palsies were observed immediately after surgery. Of the motor palsies in the bilateral upper extremities and palsies involving the lower extremities, 85.7% showed good recovery, whereas only 40% of unilateral upper extremity motor palsies showed good recovery during the follow-up period.Conclusion: In ADF for cervical OPLL, the number of operated levels was a significant factor related to the postoperative complication. Specifically, the incidence of graft/implant complications and reoperation rate increased in ADF with four or more levels.Level of Evidence: 3. [ABSTRACT FROM AUTHOR]

In cervical ossification of the posterior longitudinal ligament (OPLL), spinal cord compression causes neurologic symptoms. Neurologic symptoms showed better improvement with ADF than with LAMP, especially in patients with a high canal occupancy (>=60%) and patients with kyphosis. Although in patients with kyphotic alignment (C2-7 angle < 0 degrees), the recovery rate was higher with ADF, approach-related complications were more frequently observed in the ADF versus PDF group. [Extracted from the article]

Ossification of the spinal ligaments was first reported by Key in 1838 [[1]], based on an autopsy that revealed cervical spinal cord compression due to ossification of the posterior longitudinal ligament (OPLL) of the cervical spine. Spinal ligament ossifications such as OPLL and OLF are closely related to each other and to other spinal ligaments, such as anterior longitudinal ligament ossification and supraspinous ligament ossification. On whole-spine CT in patients with cervical OPLL, 56.2% had thoracolumbar OPLL, more than 60% had thoracic OLF, 29% had supraspinous ligament ossification, and 55.8% had nuchal ligament ossification; moreover, the severity of cervical OPLL was associated with the ossification of these other ligaments [[5]]. [Extracted from the article]

Background: Autologous bone has been used for posterior lumbar intervertebral fusion (PLIF). However, harvesting autologous bone graft is associated with donor site complications. We previously developed a hydroxyapatite/collagen (HAp/Col) composite as an osteoconductive artificial bone, characterized by having a highly porous structure with sponge‐like elasticity. This study aims to investigate the effectiveness of HAp/Col composite with bone marrow aspirate (BMA) as a graft substitute in PLIF for the treatment of lumbar spinal diseases. Methods: This study prospectively investigated patients who received one-level PLIF. For the interbody fusion, two titanium cages were inserted. On the one side of interbody space, HAp/Col composite incorporated with BMA filling the titanium cage was grafted. On the other side, local bone graft (LBG) harvested during decompressive laminotomy was grafted and then one-level instrumentation using pedicle screws was performed. The target levels were at L2/3 in 2 cases, L3/4 in 3 cases, L4/5 in 36 cases, and L5/S in 5 cases. We evaluated clinical symptoms and radiological outcomes of 46 patients and compared the fusion status of HAp/Col composite with that of LBG. Results: The 1-year postoperative CT evaluation demonstrated that, in the HAp/Col, a complete fusion was observed in 38 patients (82.6%), whereas in the LBG, a complete fusion was observed in 35 patients (76.1%). There were no statistical differences between the HAp/Col and LBG. In the HAp/Col, incomplete fusion was observed in five patients (10.9%) and non-fusion in two patients (4.3%), and in the LBG, incomplete fusion was observed in nine patients (19.6%) and non-fusion in two patients (4.3%). At 2 years after the surgery, complete fusion increased to 44 patients (95.7%) in the HAp/Col and 41 patients (89.1%) in the LBG. There were no significant differences in the clinical scores for lumbar spine between patients with fusion and non-fusion. Conclusions: The HAp/Col composite with BMA in the titanium cage can be effectively used as an alternative to conventional autologous LBG for intervertebral spinal fusion. Trial registration University hospital Medical Information Network, UMIN000045010, July 30th, 2021, Retrospectively registered, https://www.umin.ac.jp/english/. [ABSTRACT FROM AUTHOR]

Background: Decompression through an anterior approach is theoretically effective for the surgical treatment of cervical spondylotic amyotrophy (CSA), because the pathology usually locates at the anterior side. However, most previous studies investigated posterior surgery or a mix of anterior surgery and posterior surgery in their investigation. Only a few small case series have investigated the surgical outcomes of anterior decompression and fusion (ADF). Therefore, we conducted a multicenter retrospective study that included patients who underwent ADF for proximal-type CSA.Methods: We analyzed the outcomes of 77 consecutive spinal surgeries performed on proximal-type CSA patients who underwent ADF. Preoperative and postoperative manual muscle tests (MMT) and the patients' backgrounds, radiological findings, and complications were reviewed. We divided the cases into two groups, good-outcome group (MMT improvement ≧ 2 or improved to MMT 5) and poor-outcome group (others) and evaluated the prognostic factors for outcomes.Results: Of the 77 patients, 48 (62%) showed good neurological outcome. Multiple compressive lesions at anterior horn (AH) and/or ventral nerve roots (VNRs) were detected in 66 patients (85.7%) on the magnetic resonance images. The patients with a single compressive lesion at VNR or AH tended to show good neurological recovery when compare to those with multiple lesions. Age and duration of symptoms were related to the poor outcome in univariate analysis. Duration of symptoms was an independent factor associated with postoperative neurological outcome. The cut-off value for poor outcome was 7.0 months for the symptom duration (sensitivity: 79%, specificity: 54%, area under the curve: 0.69).Conclusions: Patients with proximal-CSA were more likely to have multiple compressive lesions at an AH and/or a VNR. The prognostic factor for poor neurological outcome was duration of symptoms of ≥7 months. [ABSTRACT FROM AUTHOR]

Although favourable surgical outcomes for myelopathy caused by cervical ossification of the posterior longitudinal ligament (OPLL) have been reported, factors significantly associated with post-operative neck pain attenuation still remain unclear. The primary aim of the present study was to determine factors significantly associated with post-operative neck pain attenuation in patients with cervical OPLL using a prospective multi-centre registry of surgically treated cervical OPLL. Significant postoperative neck pain reduction (50% reduction of neck pain) was achieved in 31.3% of patients. There was no significant difference in neck pain attenuation between surgical procedures. Statistical analyses with univariate analyses followed by stepwise logistic regression revealed neurological recovery as a factor having a significant positive association with post-operative neck pain attenuation (p = 0.04, odds ratio 5.68 (95% confidence interval: 1.27–22.2)). In conclusion, neurological recovery was an independent factor having a significant positive association with post-operative neck pain attenuation in patients with cervical myelopathy caused by OPLL who underwent cervical spine surgery. [ABSTRACT FROM AUTHOR]

Aim: Among older patients undergoing hip fracture surgery, previous studies have shown a seasonal variation of in‐hospital surgical complications. However, little is known about seasonal effects on mortality and systemic complications after hip fracture surgery. In the present study, we evaluated whether mortality and in‐hospital systemic complications are influenced by seasonal differences. Methods: We enrolled patients from a nationwide database who underwent hip fracture surgery between 2010 and 2018. The primary outcome was in‐hospital mortality. The secondary outcomes were in‐hospital systemic complications. The association between the seasonality and in‐hospital outcomes was investigated using multivariable Cox, logistic regression and causal mediation analysis. Results: With 425 856 patients (mean age 83.5 years; 79% women), overall in‐hospital mortality was 5324 (1.2%). Fall and winter were associated with a higher mortality than spring (hazard ratio [HR] 1.16; P < 0.001; HR 1.14; P = 0.001, respectively). Across all the seasons, there were 36 834 overall systemic complications (8.6%), with respiratory infection being the most frequent (18 637 [4.4%]). Among these complications, only respiratory infection showed seasonal variation, with a higher prevalence in fall and winter. The mediated effect of respiratory infection on mortality was significantly higher in fall and winter compared with spring (fall, HR 1.06, proportion mediated 36.7%; winter, HR 1.14, proportion mediated 55.0%; all P < 0.001). Conclusions: We found a significantly higher mortality in fall and winter after hip fracture surgery. Specifically, in winter, the increased in‐hospital death was largely attributed to the increased incidence of respiratory infection. Geriatr Gerontol Int 2021; 21: 398–403. [ABSTRACT FROM AUTHOR]

Background: Parkinson's disease (PD) has been found to increase the risk of postoperative complications in patients with adult spinal deformity (ASD). However, few studies have investigated this by directly comparing patients with PD and those without PD.Methods: In this multicenter retrospective cohort study, we reviewed all surgically treated ASD patients with at least 2 years of follow-up. Among them, 27 had PD (PD+ group). Clinical data were collected on early and late postoperative complications as well as any revision surgery. Radiographic parameters were evaluated before and immediately after surgery and at final follow-up, including sagittal vertical axis (SVA), thoracic kyphosis, lumbar lordosis, sacral slope, and pelvic tilt. We compared the surgical outcomes and radiographic parameters of PD patients with those of non-PD patients.Results: For early complications, the PD+ group demonstrated a higher rate of delirium than the PD- group. In terms of late complications, the rate of non-union was significantly higher in the PD+ group. Rates of rod failure and revision surgery due to mechanical complications also tended to be higher, but not significantly, in the PD+ group (p = 0.17, p = 0.13, respectively). SVA at final follow-up and loss of correction in SVA were significantly higher in the PD+ group.Conclusion: Extra attention should be paid to perioperative complications, especially delirium, in PD patients undergoing surgery for ASD. Furthermore, loss of correction and rate of non-union were greater in these patients. [ABSTRACT FROM AUTHOR]

Background: As the aging population progresses, the number of elderly hip fracture patients is increasing. Elderly patients with hip fractures have a high risk of perioperative complications. One of the major complications after surgery is surgical site infection (SSI), which requires additional surgical interventions and is associated with increased mortality. Previous literature has shown that the risk of SSI is higher during the summer season in orthopedic surgery. However, little is known about the seasonal differences in the risk of SSI after hip fracture surgery. In this study, we aimed to identify the association between seasonality and SSI.Methods: We enrolled a total of 330,803 patients undergoing hip fracture surgery (65 years or older) using the Japanese Diagnosis Procedure Combination database. The study period was from April 1, 2011, to March 31, 2016. The data were analyzed to determine the association between seasonality and the incidence of SSI, debridement procedure. The primary outcome was the incidence of SSI and debridement. Other risk factors of SSI and debridement were investigated including seasons and confounders such as sex, age, BMI, smoking status, anticoagulant intake, comorbidities, surgical procedure based on medical diagnosis, waiting times for the surgery, and hospital surgical volume based on the previous literature, the risk of SSI and debridement.Results: Hip fracture surgeries performed in summer showed the highest risk for SSI and debridement. The risk for SSI was significantly associated with spring, and summer compared to winter (odds ratio [OR], 1.18; p, 0.016; OR, 1.19; p, 0.012, respectively). The incidence of debridement procedures after the initial surgery was also associated with spring, summer, and fall: the risk was the highest in summer (OR, 1.34; p, <0.001). Obesity, smoking history, number of comorbidities, anticoagulant intake before surgery, longer waiting time for surgery, and small hospital surgical volume were significantly associated with the risk of SSI.Conclusions: We found a significant association between SSI after surgery for hip fractures and seasonality. Surgeries performed in summer had the highest risk for SSI and subsequent debridement procedures. [ABSTRACT FROM AUTHOR]

Background: The optimal surgical procedure for the treatment of cervical spondylotic myelopathy (CSM) remains controversial because there are few comprehensive studies that have investigated the surgical methods. Therefore, we conducted a systematic review and meta-analysis to evaluate evidence in the literature and to compare the surgical outcomes between anterior decompression with fusion (ADF) and laminoplasty, which are representative procedures for CSM.Methods: An extensive literature search was performed using PubMed, Embase, and the Cochrane Library to identify comparative studies of ADF and laminoplasty for CSM. The language was restricted to English, and the publication period was from January 2001 to July 2019. We only included studies of CSM and excluded studies that involved patients with ossification of the posterior longitudinal ligament and treatments with posterior instrumented fusion. We extracted outcomes from the studies, such as preoperative and postoperative Japanese Orthopaedic Association (JOA) scores, cervical alignment, surgical complications and reoperation rates. Then, a meta-analysis was performed on these surgical outcomes.Results: Nine studies were obtained, and the quality of the studies was acceptable. In the meta-analysis, the preoperative JOA score was similar between the ADF and laminoplasty groups. The postoperative JOA scores and neurological recovery rates were not different between the ADF and laminoplasty groups. ADF exhibited more favorable results than laminoplasty in terms of postoperative cervical alignment. In contrast, overall complications were more frequently observed in the ADF group than in the laminoplasty group, leading to higher rates of reoperation. However, postoperative neck pain was more frequently observed in the laminoplasty group than in the ADF group.Conclusions: This systematic review and meta-analysis showed both the merits and shortcomings of ADF and laminoplasty. ADF and laminoplasty showed similar results in terms of neurological recovery. Postoperative cervical lordosis was better preserved with ADF than with laminoplasty. However, ADF was associated with a higher incidence of surgical complications than laminoplasty. [ABSTRACT FROM AUTHOR]

Background: The optimal surgical procedure for the treatment of cervical spondylotic myelopathy (CSM) remains controversial. Recently, laminectomy/laminoplasty with instrumented fusion (LAMF) has been increasingly applied to treat CSM. However, few comprehensive studies have compared anterior decompression with fusion (ADF) and LAMF. Therefore, we conducted a meta-analysis to evaluate the evidence in the literature and to compare the surgical outcomes between the 2 procedures. Since the surgical outcomes and risks differ between patients with CSM and ossification of the posterior longitudinal ligament (OPLL) and between only posterior decompression and decompression with fusion treatments, we excluded patients with OPLL and patients with only posterior decompression in this review.Methods: An extensive literature search was performed using PubMed, Embase, and the Cochrane Library to identify comparative studies of ADF and LAMF for the treatment of CSM. The language was restricted to English, and the publication period was from January 2001 to July 2019. We only included studies about CSM and excluded studies that involved patients with ossification of the posterior longitudinal ligament and with the treatment of posterior decompression without fusion. We extracted outcomes from the studies, such as preoperative and postoperative Japanese Orthopaedic Association (JOA) scores, neck disability index (NDI) scores, cervical alignment data, and surgical complications. Then, a meta-analysis was performed on these surgical outcomes.Results: Eleven studies were obtained, and the quality of the studies was acceptable. In the meta-analysis, the pre- and postoperative JOA scores were similar between the ADF and LAMF groups. The ADF group exhibited more favorable results than the LAMF group in terms of postoperative cervical alignment and the NDI. Overall complications were similar between the ADF and LAMF groups; however, C5 palsy was more frequently observed in the LAMF group than in the ADF group.Conclusions: While the ADF and LAMF groups demonstrated similar results in terms of neurological recovery, postoperative cervical lordosis and NDI scores were more favorable with ADF than with LAMF. The overall complication rate was similar between the ADF and LAMF groups. Surgeons should understand the merits and shortcomings of both procedures when deciding on a surgical procedure. [ABSTRACT FROM AUTHOR]

Background: Ossification of the posterior longitudinal ligament of the spine (OPLL) is characterized by heterotopic bone formation in the posterior longitudinal ligament of the spine. We know that the size and distribution of the ossified lesions in patients with OPLL are different in each case. However, the characteristics of the patients with radiologically severe cervical OPLL remain unknown.Methods: The participants of our study were symptomatic patients with cervical OPLL who were diagnosed by standard radiographs of the cervical spine. Whole-spine CT data and demographic data such as age and sex were obtained from 20 institutions belonging to the Japanese Multicenter Research Organization for Ossification of the Spinal Ligament. According to the number of the levels involved by OPLL, we stratified the patients into two subgroups: severe group (S-group) and non-severe group (NS-group) to delineate the characteristics of radiologically severe patients with cervical OPLL. We also evaluated the most compressed level and the degree of occupying ratio of cervical spinal canal by OPLL at the most compressed level.Results: A total of 234 patients with a mean age of 65 years were recruited. The S-group consisted of 48 patients (21%, 12 females and 36 males) and the NS-group consisted of 92 patients (79%, 22 females and 70 males). The mean age of males in the S-group (68 years old) was significantly higher than that of males in the NS-group (64 years old); however there was no significant difference in the mean age in females between the S-group (69 years old) and the NS-group (66 years old). No significant difference of body mass index, ossification of the nuchal ligament-positivity and presence of diabetes mellitus were found between the S- and the NS-group.Conclusions: It is likely that the manner of extension of cervical OPLL is different between male and female patients. [ABSTRACT FROM AUTHOR]

Background: The optimal treatment of osteoporosis after reconstruction surgery for osteoporotic vertebral fractures (OVF) remains unclear. In this multicentre retrospective study, we investigated the effects of typically used agents for osteoporosis, namely, bisphosphonates (BP) and teriparatide (TP), on surgical results in patients with osteoporotic vertebral fractures.Methods: Retrospectively registered data were collected from 27 universities and affiliated hospitals in Japan. We compared the effects of BP vs TP on postoperative mechanical complication rates, implant-related reoperation rates, and clinical outcomes in patients who underwent posterior instrumented fusion for OVF. Data were analysed according to whether the osteoporosis was primary or glucocorticoid-induced.Results: A total of 159 patients who underwent posterior instrumented fusion for OVF were included. The overall mechanical complication rate was significantly lower in the TP group than in the BP group (BP vs TP: 73.1% vs 58.2%, p = 0.045). The screw backout rate was significantly lower and the rates of new vertebral fractures and pseudoarthrosis tended to be lower in the TP group than in the BP group. However, there were no significant differences in lumbar functional scores and visual analogue scale pain scores or in implant-related reoperation rates between the two groups. The incidence of pseudoarthrosis was significantly higher in patients with glucocorticoid-induced osteoporosis (GIOP) than in those with primary osteoporosis; however, the pseudoarthrosis rate was reduced by using TP. The use of TP also tended to reduce the overall mechanical complication rate in both primary osteoporosis and GIOP.Conclusions: The overall mechanical complication rate was lower in patients who received TP than in those who received a BP postoperatively, regardless of type of osteoporosis. The incidence of pseudoarthrosis was significantly higher in patients with GIOP, but the use of TP reduced the rate of pseudoarthrosis in GIOP patients. The use of TP was effective to reduce postoperative complications for OVF patients treated with posterior fusion. [ABSTRACT FROM AUTHOR]

Ossification of the posterior longitudinal ligament (OPLL) can occur throughout the entire spine and can sometimes lead to spinal disorder. Although patients with OPLL sometimes develop physical limitations because of pain, the characteristics of pain and effects on activities of daily living (ADL) have not been precisely evaluated in OPLL patients. Therefore, we conducted a multi-center prospective study to assess whether the symptoms of cervical OPLL are different from those of cervical spondylosis (CS). A total of 263 patients with a diagnosis of cervical OPLL and 50 patients with a diagnosis of CS were enrolled and provided self-reported outcomes, including responses to the Japanese Orthopaedic Association (JOA) Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), JOA Back Pain Evaluation Questionnaire (JOABPEQ), visual analog scale (VAS), and SF-36 scores. The severity of myelopathy was significantly correlated with each domain of the JOACMEQ and JOABPEQ. There was a negative correlation between the VAS score for each domain and the JOA score. There were significantly positive correlations between the JOA score and the Mental Health, Bodily Pain, Physical Functioning, Role Emotional, and Role Physical domains of the SF-36. One-to-one matching resulted in 50 pairs of patients with OPLL and CS. Although there was no significant between-group difference in scores in any of the domains of the JOACMEQ or JOABPEQ, the VAS scores for pain or numbness in the buttocks or limbs were significantly higher in the CS group; however, there was no marked difference in low back pain, chest tightness, or numbness below the chest between the two study groups. The scores for the Role Physical and Body Pain domains of the SF-36 were significantly higher in the OPLL group than in the CS group, and the mean scores for the other domains was similar between the two groups. The results of this study revealed that patients with OPLL were likely to have neck and low back pain and restriction in ADL. No specific type of pain was found in patients with OPLL when compared with those who had CS. [ABSTRACT FROM AUTHOR]

Background: The optimal surgical procedure for the treatment of cervical ossification of the posterior longitudinal ligament (OPLL) remains controversial because there are few comprehensive studies investigating the surgical methods. Therefore, we conducted a systematic review and meta-analysis to evaluate evidence in the literature and compare the surgical outcomes of anterior decompression with fusion (ADF) and laminoplasty (LAMP), which are representative procedures for cervical OPLL.Methods: An extensive literature search was performed using PubMed, Embase, and the Cochrane Library to identify comparative studies of ADF and LAMP for cervical OPLL. The language was restricted to English, and the year of publication was from January 1980 to December 2018. We extracted outcomes from the studies, such as preoperative and postoperative Japanese Orthopaedic Association (JOA) score, cervical alignment, surgical complications and reoperation rate. Then, meta-analysis was performed for these surgical outcomes.Results: Twelve studies were obtained, including 1 prospective cohort study and 11 retrospective cohort studies. In the meta-analysis, neurological recovery rate in JOA score was greater in ADF than in LAMP, especially in patients with a large canal occupying ratio (≥60%) and preoperative kyphotic alignment. ADF also exhibited more favorable results in postoperative cervical alignment. In contrast, operating time and intraoperative blood loss were greater in ADF. Surgical complications were more frequently seen in ADF, leading to higher rates of reoperation.Conclusions: This systematic review and meta-analysis showed both the merits and shortcomings of ADF and LAMP. ADF resulted in more favorable neurological recovery compared to LAMP, especially for patients with massive OPLL and kyphotic alignment. Postoperative cervical lordosis was also better preserved in ADF. However, ADF was associated with greater surgical invasion and higher incidences of surgical complications. [ABSTRACT FROM AUTHOR]

Reconstruction of a bone defect using the Masquelet induced membrane technique has been well described. However, there are few reports of arthrodesis using this technique. In this case report, we describe a modified Masquelet technique for ankle arthrodesis with nailing. The patient was a 32-year-old man who sustained an open fracture of the right ankle with a substantial osteochondral defect as a result of a fall. Immediately after the injury, a staged procedure using the Masquelet technique was planned. The bone defect was filled with bone cement in the acute stage, but replacement of the cement was needed 6 months after the injury because of a prolonged inflammatory reaction. Ten months after the injury, the bone cement was removed, and ankle arthrodesis was performed using an IM nail with a combination of autologous and artificial bone. As a modification of the Masquelet technique, the anterior surface of the transplant site was covered with a large but thin layer of cortical bone instead of suturing the incised membrane. At 1 year postoperatively, firm bony union was achieved and the implant was removed. At follow-up 3 years after his injury, the patient is able to walk, undertake physical work, and has no clinical signs of infection. Our experience suggests that a modified induced membrane technique may be useful when treating an open limb fracture with an extensive osteochondral defect where preservation of the joint is difficult and arthrodesis is considered. [ABSTRACT FROM AUTHOR]

Purpose: Distal-type cervical spondylotic amyotrophy (CSA) is a rare form of cervical spondylosis that causes muscle weakness of upper extremities. The pathophysiology and appropriate surgical method for the treatment of CSA are still controversial. We investigated clinical outcomes in surgically treated distal-type CSA.Methods: The authors executed an analysis of the outcomes of 43 consecutive spinal surgeries performed in distal-type CSA patients. The duration of symptoms, perioperative manual muscle test (MMT) results, radiological findings, and perioperative complications were reviewed. We compared surgical outcomes between different approaches and examined the factors related to poor outcomes (MMT improvement ≤ 0) after surgery.Results: The pathophysiology of CSA was mostly caused by a combination of multiple lesions in the anterior horn and/or nerve root. Nineteen of 29 patients (65.5%) who received anterior approach methods were included in the good outcome group (MMT improvement ≥ 1), whereas 7 of 14 patients (50.0%) in the posterior group were classified as good. In the anterior group, the mean MMT grade significantly improved from 2.6 to 3.4 (p = 0.0035) despite the higher rate of complications. The duration of symptoms was substantially associated with poor outcomes. The MMT grade significantly improved from 2.2 to 3.2 (p = 0.0118) in the < 6 months group. Cervical alignments and preoperative MMT grade were not statistically associated with poor outcomes.Conclusions: Patients with poor outcomes had symptoms for a longer duration. We found tolerable clinical outcomes within 6 months from onset. The anterior approaches might be recommended because this procedure significantly improved MMT levels in the hands. These slides can be retrieved under Electronic Supplementary Material. [ABSTRACT FROM AUTHOR]

Background: Diffuse idiopathic skeletal hyperostosis (DISH) increases the spine's susceptibility to unstable fractures that can cause neurological deterioration. However, the detail of injury is still unclear. A nationwide multicenter retrospective study was conducted to assess the clinical characteristics and radiographic features of spinal fractures in patients with DISH.Methods: Patients were eligible for this study if they 1) had DISH, defined as flowing ossification along the anterolateral aspect of at least four contiguous vertebral bodies, and 2) had an injury in the ankylosing spine. This study included 285 patients with DISH (221 males, 64 females; mean age 75.2 ± 9.5 years).Results: The major cause of injury was falling from a standing or sitting position; this affected 146 patients (51.2%). Diagnosis of the fracture was delayed in 115 patients (40.4%). Later neurological deterioration by one or more Frankel grade was seen in 87 patients (30.5%). The following factors were significantly associated with neurological deficits: delayed diagnosis (p = 0.033), injury of the posterior column (p = 0.021), and the presence of ossification of the posterior longitudinal ligament (OPLL) (p < 0.001). The majority of patients (n = 241, 84.6%) were treated surgically, most commonly by conventional open posterior fixation (n = 199, 69.8%). Neurological improvement was seen in 20.0% of the conservatively treated patients, and in 47.0% of the patients treated surgically.Conclusions: Minor trauma could cause spinal fractures in DISH patients. Delayed diagnosis, injury of the posterior column, and the presence of OPLL were significantly associated with neurological deterioration. Patients with neurological deficits or unstable fractures should be treated by fixation surgery. [ABSTRACT FROM AUTHOR]

Background Context: Surgical treatment of cervical ossification of the posterior longitudinal ligament (OPLL) has a high risk of various complications. Anterior decompression with fusion (ADF) and laminoplasty (LAMP) are the most representative surgical procedures. However, few studies have compared the two procedures in terms of perioperative surgical complications.Purpose: To compare the perioperative complications post-ADF and LAMP for cervical OPLL using a large national inpatient database.Study Design: A retrospective cohort study with propensity score matching analysis.Patient Sample: Overall, 8,718 (ADF/LAMP:1,333/7,485) patients who underwent surgery for cervical OPLL from April 1, 2010 to March 31, 2016 in hospitals using the diagnosis procedure combination were analyzed.Outcome Measures: The occurrence of postoperative complications during hospitalization.Methods: We compared the perioperative systemic and local complications, reoperation rates, and costs between ADF and LAMP using propensity score matching analysis.Results: One-to-one matching resulted in 1,192 pairs of patients who underwent ADF and LAMP. The postoperative cardiovascular event rate was significantly higher (ADF/LAMP=1.9/0.8%, p=.013) in the ADF group. The incidence rates of dysphagia (similarly, 2.4/0.2%, p<.001), pneumonia (1.0/0.3%, p=.045), and spinal fluid leakage (2.4/0.4%, p<.001) were also higher in the ADF group, even after matching. The costs were also higher in the ADF group. However, surgical site infection (2.0/3.4%, p=.033) was significantly lower in the ADF group. No significant difference in the reoperation rates was found between the groups.Conclusion: The present study, using a large nationwide database, demonstrated that perioperative complications were more common in the ADF group, but that surgical site infection (SSI) was more frequently observed in the LAMP group. [ABSTRACT FROM AUTHOR]

Background: Previous studies have shown that patients with cervical ossification of the posterior longitudinal ligament (OPLL) often have co-existing ossification of the nuchal ligament (ONL). However, no studies have focused on ONL and its relevance to the severity of OPLL or ossification of other spinal ligaments, such as anterior longitudinal ligament (OALL), ligamentum flavum (OLF), and supraspinous/interspinous ligament (OSIL).Methods: In this multicenter study, we investigated ossification of the spinal ligaments in the whole spine computed tomography (CT) images of 233 cervical OPLL patients. The severity of ossification was evaluated using ossification index for each spinal ligament, calculated as the sum of the level of ossification. We compared the severity of ossification in each spinal ligament between patients with ONL and those without ONL. Furthermore, we investigated how the number of segments, where ONL exists, affects the severity of ossification in each spinal ligament.Results: One hundred thirty patients (55.8%) had co-existing ONL in the cervical OPLL patients included in this study. The ONL (+) group included more male and aged patients. The cervical ossification indexes of OPLL and OALL were higher in ONL (+) patients than in ONL (-) patients. The thoracolumbar ossification indexes of OALL and OSIL were also higher in ONL (+) patients. Logistic regression analysis revealed that age, gender and cervical OA-index were independent factors correlating to the existence of ONL. In the cervical spine, both the ossification indexes of OALL and OPLL increased as the levels of ONL increased. Similarly, in the thoracolumbar spine, both the ossification indexes of OALL and OSIL were increased as the levels of cervical ONL increased. In the multiple regression analysis, cervical OA-index and thoracolumbar OSI-index showed significant correlation with the number of ONL levels.Conclusions: Co-existence of ONL in cervical OPLL patients was associated with the severity of spinal hyperostosis especially in cervical OPLL, OALL, thoracolumbar OALL and OSIL. [ABSTRACT FROM AUTHOR]

Purpose: Postoperative complication prediction helps surgeons to inform and manage patient expectations. Deep learning, a model that finds patterns in large samples of data, outperform traditional statistical methods in making predictions. This study aimed to create a deep learning-based model (DLM) to predict postoperative complications in patients with cervical ossification of the posterior longitudinal ligament (OPLL). Methods: This prospective multicenter study was conducted by the 28 institutions, and 478 patients were included in the analysis. Deep learning was used to create two predictive models of the overall postoperative complications and neurological complications, one of the major complications. These models were constructed by learning the patient's preoperative background, clinical symptoms, surgical procedures, and imaging findings. These logistic regression models were also created, and these accuracies were compared with those of the DLM. Results: Overall complications were observed in 127 cases (26.6%). The accuracy of the DLM was 74.6 ± 3.7% for predicting the overall occurrence of complications, which was comparable to that of the logistic regression (74.1%). Neurological complications were observed in 48 cases (10.0%), and the accuracy of the DLM was 91.7 ± 3.5%, which was higher than that of the logistic regression (90.1%). Conclusion: A new algorithm using deep learning was able to predict complications after cervical OPLL surgery. This model was well calibrated, with prediction accuracy comparable to that of regression models. The accuracy remained high even for predicting only neurological complications, for which the case number is limited compared to conventional statistical methods. [ABSTRACT FROM AUTHOR]

Background: There have been no prospective studies comparing anterior surgery and posterior method in terms of long-term outcomes. The purposes of this study is to clarify whether there is any difference in long-term clinical and radiologic outcomes of anterior decompression with fusion (ADF) and laminoplasty (LAMP) for the treatment of cervical spondylotic myelopathy (CSM).Methods: Ninety-five patients were prospectively treated with ADF or LAMP for CSM in our hospital from 1996 through 2003. On alternate years, patients were enrolled to receive ADF (1997, 1999, 2001, and 2003: ADF group, n = 45) or LAMP (1996, 1998, 2000, and 2002: LAMP group, n = 50). We excluded 19 patients who died during follow-up, and 25 who were lost to follow-up. Clinical outcomes were evaluated by the recovery rate of the Japanese Orthopaedic Association (JOA) score between the two groups. Sagittal alignment of the C2-7 lordotic angle and range of motion (ROM) in flexion and extension on plain X-ray were measured.Results: Mean age at the time of surgery was 58.3 years in the ADF group and 57.9 years in the LAMP group. Mean preoperative JOA score was 10.0 and 10.5, respectively. Mean recovery rate of the JOA score at 3-5 years postoperatively was significantly higher in the ADF group (p < 0.05). Reoperation was required in 1 patient for pseudarthrosis and in 1 patient for recurrence of myelopathy in the ADF group; no patient in the LAMP group underwent a second surgery. There was a significant difference in maintenance of the lordotic angle in the ADF group compared with the LAMP group (p < 0.05), but not in ROM.Conclusions: Both ADF and LAMP provided similar good outcomes at 10-year time-point whereas ADF could achieve more satisfactory outcomes and better sagittal alignment at the middle-term. However, the incidence of reoperation and complication in the ADF group were higher than those in the LAMP group.Study Design: A prospective comparative study (not randomized). [ABSTRACT FROM AUTHOR]

Purpose: Cervical sagittal balance has received increased attention as an important determinant of radiological and clinical outcomes. However, no prospective studies have compared the impact of cervical sagittal balance between anterior and posterior surgeries. We previously conducted a prospective study comparing anterior decompression with fusion (ADF) and laminoplasty (LAMP) for degenerative cervical myelopathy (DCM) and reported; however, analysis of cervical alignment within the concept of sagittal balance has yet to be performed, because that concept has recently been proposed. This study aimed to review this prospective cohort, specifically focusing on cervical sagittal balance.Methods: We prospectively performed ADF or LAMP for DCM patients based on the year of enrollment: ADF was performed in odd-numbered years and LAMP in even-numbered years. Cervical lateral X-ray images taken in the neutral standing position were evaluated preoperatively and at a 1-year follow-up. The radiographic measurements included the following: (1) CL (cervical lordosis: C2-7 lordotic angle), (2) CGH (center of gravity of the head)-C7 SVA (sagittal vertical axis), and (3) C7 slope. The clinical results were evaluated using the Japanese Orthopedic Association scoring system for cervical myelopathy (C-JOA score).Results: We analyzed the data for 66 patients (ADF n = 28, LAMP n = 38). While the CL and CGH-C7 SVA in the ADF were unchanged after the operation, those in the LAMP group worsened, especially in patients with preoperative cervical sagittal imbalance. The C7 slopes were not affected by the operation in either group. The postoperative decreases in the CL in the LAMP group correlated with the preoperative CGH-C7 SVA (r = 0.618, P < 0.01), but those in ADF group did not. In patients with preoperative cervical sagittal imbalance (CGH-C7 SVA ≥40 mm), the recovery rate of the C-JOA score in the ADF group was superior to that in the LAMP group (67.3 vs. 39.8 %). In contrast, for patients without cervical sagittal imbalance, the recovery rate of the C-JOA score showed no significant difference between the ADF and LAMP groups (64.5 vs. 58.7 %).Conclusions: Postoperative cervical sagittal alignment and balance were maintained after ADF but deteriorated following LAMP, especially in patients with preoperative CGH-C7 SVA ≥40 mm. In these patients, neurological recovery after LAMP was unsatisfactory. LAMP is not suitable for degenerative cervical myelopathy patients with preoperative cervical sagittal imbalance. [ABSTRACT FROM AUTHOR]

Background Context: Previous studies have shown that compared with laminoplasty, anterior decompression with fusion (ADF) is superior for postoperative neurologic improvement in patients with massive cervical ossification of the posterior longitudinal ligament (OPLL) with a ≥50% canal occupying ratio. However, it is unknown which method, ADF or posterior decompression with fusion (PDF), is more effective for the treatment of massive OPLL.Purpose: This study aimed to investigate the surgical outcomes of ADF and PDF for the treatment of massive OPLL.Study Design: A multicenter retrospective case-control study was carried out.Patient Sample: A total of 61 OPLL patients with a ≥50% canal occupying ratio were included in this study. The mean age of the patients was 60.9 years (49 males and 12 females); 39 patients (31 males and 8 females, average age 61.1 years) underwent ADF, and 22 patients underwent PDF (18 males and 4 females, average age 60.6 years).Outcome Measures: The data collected from both groups included age, gender, neurologic symptoms evaluated based on the Japanese Orthopedic Association score, neck pain assessed using the visual analogue scale, and radiographic parameters, including cervical lordosis and the OPLL canal occupying ratio.Methods: Clinical and radiological outcomes were compared between the ADF and PDF groups with a minimum of 2 years follow-up.Results: There were no significant differences in the postoperative neurologic recovery rate between the two groups. However, in patients with kyphotic alignment (C2-C7 angle <0 degrees), the recovery rate was higher in the ADF group. Postoperative cervical pain was greater in the PDF group. The improvement in cervical alignment at C2-C7 was greater in the ADF group. The operating time was longer in the ADF group, whereas the intraoperative blood loss was greater in the PDF group. Approach-related complications were more frequently observed in the ADF group than in the PDF group.Conclusions: The present study demonstrated that the postoperative recovery rate was similar in the ADF and PDF group. In patients with massive OPLL with kyphotic alignment, neurologic recovery rate in the ADF was superior to that in the PDF (in situ fusion). Additionally, postoperative neck pain was less severe in the ADF group. However, the occurrence of perioperative complications was more common in the ADF group. [ABSTRACT FROM AUTHOR]

Ossification of the posterior longitudinal ligament (OPLL) can cause severe and irreversible paralysis in not only the cervical spine but also the thoracolumbar spine. To date, however, the prevalence and distribution of OPLL in the whole spine has not been precisely evaluated in patients with cervical OPLL. Therefore, we conducted a multi-center study to comprehensively evaluate the prevalence and distribution of OPLL using multi-detector computed tomography (CT) images in the whole spine and to analyze what factors predict the presence of ossified lesions in the thoracolumbar spine in patients who were diagnosed with cervical OPLL by plain X-ray. Three hundred and twenty-two patients with a diagnosis of cervical OPLL underwent CT imaging of the whole spine. The sum of the levels in which OPLL was present in the whole spine was defined as the OP-index and used to evaluate the extent of ossification. The distribution of OPLL in the whole spine was compared between male and female subjects. In addition, a multiple regression model was used to ascertain related factors that affected the OP-index. Among patients with cervical OPLL, women tended to have more ossified lesions in the thoracolumbar spine than did men. A multiple regression model revealed that the OP-index was significantly correlated with the cervical OP-index, sex (female), and body mass index. Furthermore, the prevalence of thoracolumbar OPLL in patients with a cervical OP-index ≥ 10 was 7.8 times greater than that in patients with a cervical OP-index ≤ 5. The results of this study reveal that the extent of OPLL in the whole spine is significantly associated with the extent of cervical OPLL, female sex, and obesity. [ABSTRACT FROM AUTHOR]

Purpose: A multi-detector computed tomography (CT) imaging system with a mobile scanner gantry in the operating room can provide intraoperative reconstructed images with a high resolution. We devised a technique for cervical pedicle screw (CPS) placement using the mobile CT system and evaluated the accuracy of this technique.Methods: Forty-eight patients who underwent cervical fixation using CPSs were prospectively enrolled in this study. Initial pedicle probing was performed approximately to the depth of the posterior aspect of the vertebral body using fluoroscopic lateral view, and a marking pin was put in place. Intraoperative CT images were obtained to confirm whether the position of the marking pin was accurate. After adequate modification of the trajectory was performed, an appropriately sized CPS was inserted. The accuracy of the CPS was evaluated using postoperative reconstructed CT images, and compared with a historical control group of 22 patients (CPS insertion using only fluoroscopy).Results: A total of 193 CPSs were inserted. Intraoperative CT images demonstrated that 12.4 % of the initial probings were not accurate, and modification of the trajectory was required. On postoperative CT, 92.7 % of the CPSs were found to be placed accurately: the accuracy was significantly higher than the control group (80.9 %). In the cases using intraoperative CT images, only 1.0 % of the screws were judged to show grade 2 screw misplacement; no neurovascular complications associated with screw placement were observed.Conclusions: The technique of CPS placement using mobile CT was shown to be safe and effective in preventing catastrophic complications associated with CPS insertion. [ABSTRACT FROM AUTHOR]

Study Design: A retrospective cohort study. Objective: The aim of this study is to investigate the preoperative factors for postlaminoplasty kyphotic deformity in cervical spondylotic myelopathy (CSM) patients without preoperative kyphotic alignment focused on the cervical sagittal balance. Summary Of Background Data: After laminoplasty (LAMP), appropriate decompression may be obtained when cervical lordosis is maintained to allow the posterior shift of the spinal cord. Therefore, LAMP is not suitable for patients with preoperative cervical kyphosis. However, we sometimes encounter patients who developed postoperative kyphosis despite normal preoperative alignment. The risk factors of postlaminoplasty kyphotic deformity for the patients without preoperative kyphotic alignment are not well known. Methods: A total of 174 consecutive patients who received a double-door LAMP for CSM without preoperative kyphotic alignment and completed a 1-year follow-up were enrolled. Cervical lateral X-ray images obtained in the standing position were measured at the preoperative stage and during a 1-year follow-up visit. The radiographic measurements included the following: (1) C2-7 lordotic angle (C2-7 angle), (2) C2-7 range of motion (C2-7 ROM), (3) CGH (center of gravity of the head)-C7 SVA, and (4) C7 slope. The clinical results were evaluated using the Japanese Orthopedic Association score system for cervical myelopathy (C-JOA score). Results: Postoperative kyphotic deformity was observed in 9 patients (5.2%). The recovery rates of the C-JOA scores at the 1-year follow-up period in the kyphotic deformity (+) group were inferior to those of the kyphotic deformity (-) group. The CGH-C7 SVA and advanced age were detected as preoperative risk factors using multivariate analysis. Cutoff values for predicting postlaminoplasty kyphotic deformity were a CGH-C7 SVA = 42 mm and an age of 75 years. Conclusion: Cervical sagittal imbalance and advanced age were the preoperative risk factors for kyphotic deformity after LAMP for CSM in patients without preoperative cervical kyphotic alignment. Level Of Evidence: 4. [ABSTRACT FROM AUTHOR]

We previously demonstrated the importance of quality management procedures for the handling of human bone marrow stromal cells (hBMSCs) and provided evidence for the existence of osteogenic inhibitor molecules in BMSCs. One candidate inhibitor is the ephrin type-A receptor 5 (EphA5), which is expressed in hBMSCs and upregulated during long-term culture. In this study, forced expression of EphA5 diminished the expression of osteoblast phenotypic markers. Downregulation of endogenous EphA5 by dexamethasone treatment promoted osteoblast marker expression. EphA5 could be involved in the normal growth regulation of BMSCs and could be a potential marker for replicative senescence. Although Eph forward signaling stimulated by ephrin-B-Fc promoted the expression of ALP mRNA in BMSCs, exogenous addition of EphA5-Fc did not affect the ALP level. The mechanism underlying the silencing of EphA5 in early cultures remains unclear. EphA5 promoter was barely methylated in hBMSCs while histone deacetylation could partially suppress EphA5 expression in early-passage cultures. In repeatedly passaged cultures, the upregulation of EphA5 independent of methylation could competitively inhibit osteogenic signal transduction pathways such as EphB forward signaling. Elucidation of the potential inhibitory function of EphA5 in hBMSCs may provide an alternative approach for lineage differentiation in cell therapy strategies and regenerative medicine. [ABSTRACT FROM AUTHOR]

We previously demonstrated the importance of quality management procedures for the handling of human bone marrow stromal cells (hBMSCs) and provided evidence for the existence of osteogenic inhibitor molecules in BMSCs. One candidate inhibitor is the ephrin type-A receptor 5 (EphA5), which is expressed in hBMSCs and upregulated during long-term culture. In this study, forced expression of EphA5 diminished the expression of osteoblast phenotypic markers. Downregulation of endogenous EphA5 by dexamethasone treatment promoted osteoblast marker expression. EphA5 could be involved in the normal growth regulation of BMSCs and could be a potential marker for replicative senescence. Although Eph forward signaling stimulated by ephrin-B-Fc promoted the expression of ALP mRNA in BMSCs, exogenous addition of EphA5-Fc did not affect the ALP level. The mechanism underlying the silencing of EphA5 in early cultures remains unclear. EphA5 promoter was barely methylated in hBMSCs while histone deacetylation could partially suppress EphA5 expression in early-passage cultures. In repeatedly passaged cultures, the upregulation of EphA5 independent of methylation could competitively inhibit osteogenic signal transduction pathways such as EphB forward signaling. Elucidation of the potential inhibitory function of EphA5 in hBMSCs may provide an alternative approach for lineage differentiation in cell therapy strategies and regenerative medicine. [ABSTRACT FROM AUTHOR]

ABSTRACT The ubiquitin/proteasome system plays an important role in regulating the activity of osteoblast precursor cells. Proteasome inhibitors (PSIs) have been shown to stimulate the differentiation of osteoblast precursor cells and to promote bone formation. This raises the possibility that PSIs might be useful for enhancing fracture healing. In this study, we examined the effect of the local administration of PSI on fracture repair in rats. The effects of treatment on the healing of a fractured femur were assessed based on radiographs, micro-computed tomography (μCT) analysis, biomechanical testing, and histological analysis. PSI enhanced osteogenic differentiation in bone marrow- and periosteum-derived mesenchymal progenitor cells in vitro. Moreover, the local administration of PSI in vivo promoted fracture healing in rats, as demonstrated by an increased fracture callus volume in radiographs at 2 weeks post-fracture, and improved radiographic scores. By week 4, PSI treatment had enhanced biomechanical strength and mineral density in the callus as assessed using bending tests, and μCT, respectively. Histological sections demonstrated that PSI treatment accelerated endochondral ossification during the early stages of fracture repair. Although further investigations are necessary to assess its clinical use, the local administration of PSIs might be a novel, and effective therapeutic approach for fracture repair. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1197-1204, 2015. [ABSTRACT FROM AUTHOR]

Spinal schwannoma recurs after initial surgery at a rate of 4%–6%, with known risk factors including subtotal resection, multilevel involvement, large tumor size, and malignant histopathology. This study examined risk factors for schwannoma recurrence and residual tumor regrowth. Sixty-five patients who underwent resection of spinal schwannoma in our department between July 2010 and December 2018 and were followed up for more than 1 year were retrospectively analyzed for age, sex, follow-up duration, imaging and surgical data, recurrence, reoperation, and Japanese Orthopaedic Association scores before and 1 year after surgery. Patients with postoperative recurrence or residual tumor regrowth of >10% at the final visit (R+ group) were compared with patients without recurrence or regrowth (R– group). Multivariate logistic regression analysis was performed to analyze concurrent effects of risk factors on recurrence and regrowth. The 65 patients (mean age 52.4 years at surgery) had schwannomas involving cervical (n = 14), thoracic (n = 25), and lumbar (n = 26) spinal levels. Mean follow-up duration was 58 months. Location was intradural in 65%, extradural in 17%, and both intradural and extradural in 18%. There were 4 recurrences (6.2%), and the mean interval between surgery and recurrence was 18.8 months. Seven patients (10.8%) experienced regrowth. Comparing group R+ (n = 11) and group R– (n = 54), univariate analysis showed significant differences in Sridhar tumor classification, giant tumor (Sridhar classification II, IVb, and V), left–right and cranial–caudal tumor size, largest diameter, operative time, blood loss, subtotal resection, reoperation, fusion surgery, and follow-up duration. Multivariate logistic regression analysis revealed giant tumor (Sridhar classification types II, IVb, and V) as an independent risk factor for recurrence and regrowth. This retrospective review of 65 consecutive patients with spinal schwannoma in a single institution demonstrated that 16.9% had recurrence or regrowth, demonstrating that this potential risk should be kept in mind. [ABSTRACT FROM AUTHOR]