Factors prolonging antibiotic duration and impact of early surgery in thoracolumbar pyogenic spondylitis treated with minimally invasive posterior fixation.

PURPOSE: A standard 6-12-week course of antibiotics is recommended for pyogenic spondylitis. Recent evidence supports early minimally invasive posterior fixation surgery; however, its effect on antibiotic treatment duration is unclear. This study aims to identify factors associated with prolonged antibiotic treatment in thoracolumbar pyogenic spondylitis patients resistant to conservative treatment and assess whether early surgery can reduce treatment duration. METHODS: We retrospectively reviewed 74 patients with thoracolumbar pyogenic spondylitis undergoing minimally invasive posterior fixation at nine facilities. Patients were grouped based on antibiotic duration (≥ 6 or < 6 weeks) and timing of surgery (≤ 3 weeks or > 3 weeks of starting antibiotics). Univariable and multivariable logistic regression analyses were used to identify factors associated with prolonged antibiotic treatment and study the outcomes of patients undergoing early surgery. RESULTS: Forty-nine patients (66%) required prolonged antibiotic treatment. The presence of an iliopsoas abscess (p = 0.0006) and elevated C-reactive protein (CRP) levels (≥ 10 mg/dL, p = 0.015) were independently associated with prolonged antibiotic treatment. Early surgery significantly reduced total antibiotic duration (5.3 weeks vs. 9.9 weeks, p < 0.0001) without increasing the incidence of postoperative infection recurrences and unplanned additional surgeries. Despite factors associated with prolonged antibiotic treatment, early surgery consistently shortened the treatment duration compared to late surgery. CONCLUSIONS: Early surgery (within three weeks) with minimally invasive posterior fixation for thoracolumbar pyogenic spondylitis is associated with reduced antibiotic duration and overall treatment duration regardless of the presence of prolonging factors like iliopsoas abscess and elevated CRP levels.

Unique characteristics of bone union at the infected vertebrae after minimally invasive posterior fixation without bone grafting in thoracolumbar pyogenic spondylitis: a retrospective multicenter cohort study.

BACKGROUND: The current study aimed to evaluate the bone union rate between infected vertebrae after minimally invasive posterior fixation without bone grafting in thoracolumbar pyogenic spondylitis. METHODS: This retrospective multicenter cohort study evaluated 75 patients of posterior fixation for thoracolumbar pyogenic spondylitis that have been recorded at six relevant institutions from January 2016 to December 2022. Data on age, sex, location of infected vertebrae, number of infected disks, comorbidity, Pola classification, number of vertebrae fixed according to surgery, implant failure requiring revision surgery, and distance according to the type of infected vertebrae after surgery were evaluated. Further, their association with postoperative bone union was investigated > 12 months postoperatively. RESULTS: Finally, 40 patients were included in the study. In total, 32 (80%) patients achieved bone union at the infected vertebrae after minimally invasive posterior fixation without bone grafting. The mean duration from surgery to union was 10.7 months. Twenty-six (65%) patients initially achieved bone union at the lateral and/or anterior bridging callus. Patients with multiple-level infected disks (33%, 2/6 patients) had a lower bone union rate than those with a single-level infected disk (88%, 30/34 patients) (p = 0.0095). CONCLUSIONS: In 80% of patients, bone union at the infected vertebrae was achieved after minimally invasive posterior fixation without bone grafting in thoracolumbar pyogenic spondylitis. A total of 65% of the patients achieved initial bone union at the lateral and/or anterior bridging callus. Moreover, patients with multiple-level infected disks had a low bone union rate. Hence, the treatment strategy should be cautiously considered. TRIAL REGISTRATION: This study was registered retrospectively and all procedures used in this study including the review of patient records were approved by the institutional review board.

A study on the effect of platelet-rich plasma (PRP) to promote bone fusion in lateral interbody fusion of the lumbar spine using artificial bone.

BACKGROUND: Lateral lumbar interbody fusion (LLIF) via a retroperitoneum approach has gained popularity due to minimal invasiveness, which avoids resection of the spinous process and laminae. However, as challenges in grafting autogenous bone persist, artificial bone has been tested in Japan to fill the spinal cage. Platelet-rich plasma (PRP) contains growth factors and anti-inflammatory cytokines to promote cellular proliferation and repair damaged tissues. While the effects of PRP on tendon and ligament repair are widely known, any effects on bone healing are scarcely reported. However, PRP-loaded artificial bone carries potential to improve intervertebral bone fusion. OBJECTIVE: This study assessed whether PRP enhances intervertebral bone fusion in LLIF surgery using ß-tricalcium phosphate artificial bone. METHODS: The current study was a prospective, randomized, controlled trial. We evaluated 13 consecutive patients undergoing LLIF surgery in our hospital. Patients received artificial bone impregnated with PRP or without PRP within the same fusion cage. The primary outcome was the intervertebral bone fusion rate at 6 and 12 months postoperatively, evaluated using CT imaging. The intervertebral bone fusion rates with and without PRP loading and with and without contact part between the endplate and the artificial bone were compared. Secondary outcomes included clinical evaluations using visual analog scale scores for low back pain, buttock-leg pain, and leg numbness from the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOA-BPEQ) and the Oswestry Disability Index (ODI), plus adverse events information. RESULTS: Of the 13 patients (29 vertebral segments) included, bone fusion was observed in 43.4% of the PRP group and 26.1% of the non-PRP group at 6 months (p = 0.216). At 12 months, fusion rates were 60.9% with PRP and 34.8% without PRP (p = 0.074). The fusion rate was significantly higher in cases with good contact between the vertebral endplate and the artificial bone (p = 0.0004). Clinical scores improved postoperatively. Adverse events were in accordance with expectations from LLIF surgery and no PRP-specific events occurred. CONCLUSION: PRP did not significantly improve intervertebral bone fusion rates in LLIF surgeries, particularly in cases with poor contact between the vertebral endplate and artificial bone. While PRP may have a limited role in enhancing bone fusion, maintaining good contact between the vertebral endplate and artificial bone is crucial for successful outcomes. Further research is needed to explore optimal uses of PRP in spinal fusion surgeries.

Impact of causative organism identification on clinical outcomes after minimally invasive posterior fixation for thoracolumbar pyogenic spondylitis: multicenter retrospective cohort study.

PURPOSE: This study aimed to evaluate the difference in treatment duration and unplanned additional surgeries between patients with unidentified causative organisms on empiric antibiotics and those with identified organisms on selective antibiotics in treating thoracolumbar pyogenic spondylitis with minimally invasive posterior fixation. METHODS: This multicenter retrospective cohort study included patients with thoracolumbar pyogenic spondylitis refractory to conservative treatment who underwent minimally invasive posterior fixation. Patients were divided into the identified (known causative organism) and unidentified groups (unknown causative organism). We analyzed data on demographics, antibiotic use, surgical outcomes, and infection control indicators. RESULTS: We included 74 patients, with 52 (70%) and 22 (30%) in the identified and unidentified groups, respectively. On admission, the identified group had higher C-reactive protein (CRP) levels and more iliopsoas abscesses. The duration to postoperative CRP negative was similar in the identified and unidentified groups (7.13 vs. 6.48 weeks, p = 0.74). Only the identified group had unplanned additional surgeries due to poor infection control, affecting 6 of 52 patients (12%). Advanced age and causative organism identification increased the additional surgery odds (odds ratio [OR], 8.25; p = 0.033 and OR, 6.83; p = 0.034, respectively). CONCLUSION: The use of empiric antibiotics in minimally invasive posterior fixation was effective without identifying the causative organism and did not prolong treatment duration. In patients with identified organisms, 12% required unplanned additional surgery, indicating a more challenging infection control. Causative organism identification was associated with the need for additional surgery, suggesting a more cautious treatment strategy for these patients.

Surgical Apgar Score and Controlling Nutritional Status Score can be predictors of major postoperative complications after spine surgery.

Assessing intraoperative hemodynamics with Surgical Apgar Score (SAS) and preoperative nutritional status with the Controlling Nutritional Status (CONUT) score are said to be useful to predict postoperative complications in many surgical services, but little is reported in the field of spinal surgery. The purpose of this study was to assess the utility of SAS and the CONUT score for predicting the risk of major postoperative complications after spinal surgery. We included 659 people who undergone spinal surgery in our institute in eight consecutive years. The occurrence of postoperative major complications was investigated. Background clinical information, surgical information including the SAS and the CONUT score, and the length of postoperative hospital stay were collected. The risk factors of postoperative complications were assessed statistically. Complications occurred in 117 cases (17.8%). The multivariate analysis showed that history of diabetes mellitus (odds ratio [OR] 1.81: P = 0.035), coronary disease (OR 3.33; P = 0.009), American Society of Anesthesiologists Physical Status (OR 1.71; P = 0.025), use of instruments (OR 2.07; P = 0.026), operation time (OR 1.30; P < 0.001), SAS (OR 0.59; P < 0.001), and CONUT (OR 1.34; P < 0.001) were independent risk factors of major complications after spinal surgery. Assessing the intraoperative hemodynamics with SAS and preoperative nutritional status with the CONUT score was useful in predicting major postoperative complications after spinal surgery. People who are detected as high risked people should be managed carefully after spinal surgery.

Do Stainless-Steel Pins Coated with Fibroblast Growth Factor-Calcium Phosphatase Composite Layers Have Anti-Infective Effects?

Background: The most problematic complication of external fixation is infection at the pin insertion site. Technology that improves the adhesion of the external fixation pin to the skin, subcutaneous tissue, and bone may prevent infection at the pin site. The purpose of this study is to formulate a calcium phosphate-fibroblast growth factor (Cp-FGF) coating on a stainless-steel external fixation pin and to verify its effectiveness in reducing infection at the pin site and its possible influence on bone fixation in animal experiments. Methods: We compared stainless-steel screws without coating (SS group; n = 32), those with a calcium phosphate coating (Cp group; n = 30), those with a Cp-FGF coating (FGF group; n = 32), and those with a Cp-FGF coating having enhanced biological activity (FGF+ group; n = 32) in male Japanese white domesticated rabbits. Screws were inserted percutaneously into the bilateral proximal tibial diaphysis of the rabbits and implanted for 4 weeks. Screws and periscrew tissue were observed postoperatively for qualitatively assessing infection. Results: Infection assessment by gross findings after 4 weeks (at screw removal) showed no significant differences between the groups. Histopathological evaluation of soft tissue infection and bone tissue infection showed no significant differences between the groups for either soft tissue or bone tissue. Since neither the FGF+ group nor the FGF group showed anti-infective effects, the biological activity of FGF is not the only determining factor. We compared SEM, XRD, coating detaching test, sustained release test, and bioassay to examine physicochemical properties among the coatings but found no sufficient differences. Conclusions: It is suggested that improving the tissue adhesion to and/or biocompatibility of pins is also important to improve the in vivo performance of Cp-FGF-coated external fixation pins.

Safety and feasibility of intravenous administration of a single dose of allogenic-Muse cells to treat human cervical traumatic spinal cord injury: a clinical trial.

INTRODUCTION: Spinal cord injury (SCI) is a devastating injury and remains one of the largest medical and social burdens because of its intractable nature. According to the recent advances in stem cell biology, the possibility of spinal cord regeneration and functional restoration has been suggested by introducing appropriate stem cells. Multilineage-differentiating stress enduring (Muse) cells are a type of nontumorigenic endogenous reparative stem cell. The positive results of Muse cell transplantation for SCI was shown previously. As a first step for clinical application in human SCI, we conducted a clinical trial aiming to confirm the safety and feasibility of intravenously injected donor-Muse cells. METHODS: The study design of the current trial was a prospective, multicenter, nonrandomized, nonblinded, single-arm study. The clinical trial registration number was JRCT1080224764. Patients with a cervical SCI with a neurological level of injury C4 to C7 with the severity of modified Frankel classification B1 and B2 were included. A primary endpoint was set for safety and feasibility. Our protocol was approved by the PMDA, and the trial was funded by the Life Science Institute, Tokyo, Japan. The present clinical trial recruited 10 participants (8 males and 2 females) with an average age of 49.3 ± 21.2 years old. All 10 participants received a single dose of allogenic CL2020 (a total of 15 × 106 cells, 2.1-2.7 × 105 cells/kg of body weight), which is a Muse cell-based product produced from human mesenchymal stem cells, by an intravenous drip. RESULTS: There were two reported severe adverse events, both of which were determined to have no causal relationship with Muse cell treatment. The change in the ISNCSCI motor score, the activity of daily living and quality of life scores showed statistically significant improvements compared to those data at the time of CL2020 administration. CONCLUSION: In the present trial, no safety concerns were identified, and Muse cell product transplantation demonstrated good tolerability. Future clinical trials with appropriate study designs incorporating a control arm will clarify the definitive efficacy of single-dose allogenic Muse cell treatment with intravenous administration to treat SCI. TRIAL REGISTRATION: jRCT, JRCT1080224764. Registered 03 July 2019, https://jrct.niph.go.jp/latest-detail/jRCT1080224764 .

Multimodal Deep Learning-based Radiomics Approach for Predicting Surgical Outcomes in Patients with Cervical Ossification of the Posterior Longitudinal Ligament.

STUDY DESIGN: A retrospective analysis. OBJECTIVE: This research sought to develop a predictive model for surgical outcomes in patients with cervical ossification of the posterior longitudinal ligament (OPLL) using deep learning and machine learning (ML) techniques. SUMMARY OF BACKGROUND DATA: Determining surgical outcomes assists surgeons in communicating prognosis to patients and setting their expectations. Deep learning and ML are computational models that identify patterns from large data sets and make predictions. METHODS: Of the 482 patients, 288 patients were included in the analysis. A minimal clinically important difference (MCID) was defined as gain in Japanese Orthopaedic Association (JOA) score of 2.5 points or more. The predictive model for MCID achievement at 1 year postsurgery was constructed using patient background, clinical symptoms, and preoperative imaging features (x-ray, CT, MRI) analyzed through LightGBM and deep learning with RadImagenet. RESULTS: The median preoperative JOA score was 11.0 (IQR: 9.0-12.0), which significantly improved to 14.0 (IQR: 12.0-15.0) at 1 year after surgery ( P < 0.001, Wilcoxon signed-rank test). The average improvement rate of the JOA score was 44.7%, and 60.1% of patients achieved the MCID. Our model exhibited an area under the receiver operating characteristic curve of 0.81 and the accuracy of 71.9% in predicting MCID at 1 year. Preoperative JOA score and certain preoperative imaging features were identified as the most significant factors in the predictive models. CONCLUSION: A predictive ML and deep learning model for surgical outcomes in OPLL patients is feasible, suggesting promising applications in spinal surgery. LEVEL OF EVIDENCE: 4.

Early Recurrence of Thoracic Ossification of the Ligamentum Flavum After Posterior Decompression Surgery: A Case Report.

Thoracic ossification of the ligamentum flavum (OLF) is known to result in spinal canal stenosis and myelopathy. It is typically treated through decompressive laminectomy and resection of the ossified ligament, which is known to improve neurological deficits. However, the recurrence of OLF post-surgery remains a relatively undocumented and complex issue. The present report describes the case of a 58-year-old male patient who had obesity (BMI 34), diabetes mellitus, and Basedow's disease. The patient presented with bilateral lower limb paresthesia and associated gait impairment, resulting in an urgent hospital admission. Imaging diagnostics identified extensive thoracic ossification of the posterior longitudinal ligament and OLF, both of which resulted in significant spinal cord compression. He underwent posterior decompression with instrumented fusion from T1 to T9 and additional laminectomy and OLF resection at T10/11. Despite an initial improvement in the postoperative period, the patient developed an epidural hematoma one week following surgery, causing significant paralysis of the lower limbs. This complication was promptly addressed with hematoma removal surgery. Six months after the initial procedure, his walking function improved significantly, but eight months after surgery, he experienced a sudden regression in motor functions due to the recurrence of OLF at T10/11, necessitating an additional posterior instrumented fusion surgery. Subsequent to the additional surgical procedure, the patient experienced an amelioration in paralysis, enabling him to ambulate with the aid of a cane. The recurrence of thoracic OLF after decompression surgery is a significant concern, especially in cases where decompression without instrumented fusion is performed. When determining the surgical procedure for thoracic OLF in cases with extensive ossification of the spinal ligaments, it is crucial to consider the degree of spontaneous fusion and mobility of the spinal segments, as demonstrated in the present case. The concentration of mechanical stress due to fusion at adjacent segments and intervertebral mobility at the thoracolumbar junction may increase the risk of OLF recurrence and should be carefully assessed preoperatively, even though posterior decompression surgery is typically considered a sufficient option for thoracic OLF.

Pedicle screw insertion into infected vertebrae reduces operative time and range of fixation in minimally invasive posterior fixation for thoracolumbar pyogenic spondylitis: a multicenter retrospective cohort study.

BACKGROUND: Minimally invasive posterior fixation surgery for pyogenic spondylitis is known to reduce invasiveness and complication rates; however, the outcomes of concomitant insertion of pedicle screws (PS) into the infected vertebrae via the posterior approach are undetermined. This study aimed to assess the safety and efficacy of PS insertion into infected vertebrae in minimally invasive posterior fixation for thoracolumbar pyogenic spondylitis. METHODS: This multicenter retrospective cohort study included 70 patients undergoing minimally invasive posterior fixation for thoracolumbar pyogenic spondylitis across nine institutions. Patients were categorized into insertion and skip groups based on PS insertion into infected vertebrae, and surgical data and postoperative outcomes, particularly unplanned reoperations due to complications, were compared. RESULTS: The mean age of the 70 patients was 72.8 years. The insertion group (n = 36) had shorter operative times (146 versus 195 min, p = 0.032) and a reduced range of fixation (5.4 versus 6.9 vertebrae, p = 0.0009) compared to the skip group (n = 34). Unplanned reoperations occurred in 24% (n = 17) due to surgical site infections (SSI) or implant failure; the incidence was comparable between the groups. Poor infection control necessitating additional anterior surgery was reported in four patients in the skip group. CONCLUSIONS: PS insertion into infected vertebrae during minimally invasive posterior fixation reduces the operative time and range of fixation without increasing the occurrence of unplanned reoperations due to SSI or implant failure. Judicious PS insertion in patients with minimal bone destruction in thoracolumbar pyogenic spondylitis can minimize surgical invasiveness.

The association between variations in the number of thoracic and lumbar vertebrae and rib morphology in adolescent idiopathic scoliosis.

PURPOSE: Preoperative counting of thoracic and lumbar vertebrae is crucial in adolescent idiopathic scoliosis (AIS) due to reported anatomical variations and potential surgical site misidentification. This study investigated characteristics associated with the vertebral number variations AIS, particularly focusing on rib morphology. METHODS: Based on three-dimensional computed tomography, patients were categorized into the non-variant number group, comprising individuals with 12 thoracic and 5 lumbar vertebrae, and the variant number group, comprising individuals with different numbers of vertebrae. Additionally, the most caudal rib morphology was classified as normal, unilateral, or hypoplastic. RESULTS: A total of 359 patients were included in our study (41 males, 318 females, age: 16.3 ± 3.1 years), with 44 patients (12.3%) assigned to the variant number group. Logistic regression analysis identified unilateral ribs (odds ratio [OR]: 10.50) and lumbosacral transitional vertebrae (LSTV) (OR 6.49) as significant risk factors associated with variations. Further analysis revealed hypoplastic ribs as a significant risk factor associated with LSTV (OR: 4.58). 8 CONCLUSION: Our study suggests that abnormal rib morphology may be associated with vertebral number variations. Close attention to rib morphology is, therefore, warranted in cases with atypical vertebral numbers. Accordingly, to ensure surgical safety and accuracy, spine surgeons must communicate these variations to the surgical team, standardize nomenclature for describing them, and intraoperatively verify fusion levels with them.

Bone union-promoting effect of romosozumab in an ovariectomized rat posterolateral lumbar fusion model.

Spinal fixation surgery has been increasingly performed in patients with osteoporosis. Romosozumab, a drug that was introduced in Japan recently, is known to possibly promote bone healing. However, few studies have reported the therapeutic effects of romosozumab in clinical practice in Japan. Therefore, here, we investigated the effects of romosozumab dosage on bone fusion promotion using an ovariectomized rat spinal fusion model. Eight-week-old female Sprague-Dawley rats were matched by body weight and divided into three groups: 1.0 romosozumab (R) group (Evenity®, 25 mg/kg), 1/10R group (Evenity®, 2.5 mg/kg), and control (C) group (saline). Subcutaneous injections were administered twice a week for 8 weeks postoperatively. Computed tomography scans were performed every 2 weeks from the time of surgery till 8 weeks postoperatively. The mean fusion rates in terms of volume were significantly higher in the R groups [1/10R, 1.0R] than in the C group from 4 weeks postoperatively. The rate of increase was significantly higher in the 1.0R group from 4 weeks postoperatively and in the 1/10R group from 6 weeks postoperatively, than in the C group. The proportion of trabecular bone area was approximately 1.5 times higher in the R groups than in the C group. No significant differences were observed between the R groups. Our results suggest that romosozumab stimulates bone growth at the graft site, and similar effects were achieved at 1/10 of the standard dosage.

The Optimal Patient Position on the Surgical Table for Lateral Lumbar Interbody Fusion in Adult Spinal Deformity Using Three-Dimensional Computed Tomography: A Retrospective Study.

Introduction: Lateral lumbar interbody fusion (LLIF) techniques have been extensively used in adult spinal deformity surgery. Preoperative knowledge of the optimal position of the patient on the surgical table is essential for a safe procedure. Therefore, this study aims to determine the optimal angle for positioning the patient on the surgical table during LLIF using three-dimensional computed tomography (3DCT). Methods: Data from 59 patients (2 males, 57 females, mean age 66.3±8.6 years) with adult spinal deformities treated by performing corrective spinal surgery were included in this observational retrospective study. Simulated fluoroscopic images were obtained using 3DCT images rotated from the reference position with the spinous process of S1 as the midline to the position with the spinous process in the center of the bilateral pedicle of T12-L5. The rotation angle of each vertebra was measured and defined as the optimal rotation angle (ORA). The angle that bisected the angle between the maximum and minimum ORA was defined as the optimal mean angle of the maximum and minimum ORA (OMA) and considered the optimal angle for the patient's position on the surgical table, as this position could minimize the rotation angle of the surgical table during surgery. A multiple regression analysis was performed to predict OMA. Results: Multiple regression analysis revealed the following equation: OMA=1.959+(0.238×lumbar coronal Cobb angle)+(-0.208×sagittal vertical axis). Conclusions: When the patient is placed on the surgical table by rotating them at the OMA, the rotation of the surgical table can be reduced, ensuring a safe and efficient surgical procedure.

Effect of urgent surgery within 8 hours compared to surgery between 8 and 24 hours on perioperative complications and neurological prognosis in patients older than 70 years with cervical spinal cord injury: a propensity score-matched analysis.

OBJECTIVE: This study aimed to investigate the effect of surgery within 8 hours on perioperative complications and neurological prognosis in older patients with cervical spinal cord injury by using a propensity score-matched analysis. METHODS: The authors included 87 consecutive patients older than 70 years who had cervical spinal cord injury and who had undergone posterior decompression and fusion surgery within 24 hours of injury. The patients were divided into two groups based on the time from injury to surgery: surgery within 8 hours (group 8 hours) and between 8 and 24 hours (group 8-24 hours). Following the preliminary study, the authors established a 1:1 matched model using propensity scores to adjust for baseline characteristics and neurological status on admission. Perioperative complication rates and neurological outcomes at discharge were compared between the two groups. RESULTS: Preliminary analysis of 87 prematched patients (39 in group 8 hours and 48 in group 8-24 hours) revealed that the motor index score (MIS) on admission was lower for lower extremities (12.3 ± 15.5 vs 20.0 ± 18.6, respectively; p = 0.048), and total extremities (26.7 ± 27.1 vs 40.2 ± 30.6, respectively; p = 0.035) in group 8 hours. In terms of perioperative complications, group 8 hours had significantly higher rates of cardiopulmonary dysfunction (46.2% vs 25.0%, respectively; p = 0.039). MIS improvement (the difference in scores between admission and discharge) was greater in group 8 hours for lower extremities (15.8 ± 12.6 vs 9.0 ± 10.5, respectively; p = 0.009) and total extremities (29.4 ± 21.7 vs 18.7 ± 17.7, respectively; p = 0.016). Using a 1:1 propensity score-matched analysis, 29 patient pairs from group 8 hours and group 8-24 hours were selected. There were no significant differences in baseline characteristics, neurological status on admission, and perioperative complications between the two groups, including cardiopulmonary dysfunction. Even after matching, MIS improvement was significantly greater in group 8 hours for upper extremities (13.0 ± 10.9 vs 7.8 ± 8.3, respectively; p = 0.045), lower extremities (14.8 ± 12.7 vs 8.3 ± 11.0, respectively; p = 0.044) and total extremities (27.8 ± 21.0 vs 16.0 ± 17.5, respectively; p = 0.026). CONCLUSIONS: Results of the comparison after matching demonstrated that urgent surgery within 8 hours did not increase the perioperative complication rate and significantly improved the MIS, suggesting that surgery within 8 hours may be efficient, even in older patients.

Quantitative evaluation of the lumbar ligamentum flavum using MRI T2-mapping: Efficacy of its clinical application in patients with lumbar spinal stenosis.

OBEJECTIVE: To perform a magnetic resonance imaging T2-mapping of the ligamentum flavum in healthy individuals and patients with lumbar spinal stenosis scheduled for surgery and compare the T2 relaxation times. SUBJECTS AND METHODS: The T2 relaxation time of the ligamentum flavum was compared among 3 groups, healthy young individuals (H group (age< 50)), healthy middle-aged and older individuals (H group (age≥50)), and patients with lumbar spinal stenosis (L group). Additionally, the thickness of the ligament was measured in the axial image plane, and the occupied area ratio of each fiber was measured by staining the surgically obtained ligament, and each was correlated with the T2 relaxation time. We also evaluated the adhesion of the ligamentum flavum with the dura mater during the surgery. RESULTS: The T2 relaxation times were significantly prolonged in H group (age ≥50) and L group (P < 0.001) compared to H group (age<50). The relationship between collagen fiber and T2 relaxation times was significantly positive (r = 0.720, P < 0.001). Moreover, the relaxation times were significantly prolonged in those with adhesion of the ligamentum flavum with the dura mater (P < 0.05). The cut-off for the relaxation time was 50 ms (sensitivity: 62.50%, false positive rate: 10.8%). CONCLUSION: Healthy middle-aged and older individuals and patients with lumbar spinal stenosis and adhesion of the ligamentum flavum with the dura mater have prolonged T2 relaxation times. Hence, the adhesion between the ligamentum flavum and dura mater should be considered in cases with a relaxation time ≥50 ms.

Hidden Bow Hunter's Syndrome Diagnosed Using Dynamic Cerebral Angiography and Successfully Treated with Spinal Surgery: A Case Report and Review of the Literature.

Hidden bow hunter's syndrome (HBHS) is a rare disease in which the vertebral artery (VA) occludes in a neutral position but recanalizes in a particular neck position. We herein report an HBHS case and assess its characteristics through a literature review. A 69-year-old man had repeated posterior-circulation infarcts with right VA occlusion. Cerebral angiography showed that the right VA was recanalized only with neck tilt. Decompression of the VA successfully prevented stroke recurrence. HBHS should be considered in patients with posterior circulation infarction with an occluded VA at its lower vertebral level. Diagnosing this syndrome correctly is important for preventing stroke recurrence.

Cervical Posterior Instrumentation Surgery Using a Patient-Specific Screw Guide Templating System: A Case Report.

Posterior cervical pedicle screw (CPS) is one of the most robust forms of posterior instrumentation. Nonetheless, the spinal cord, nerve roots, and vertebral artery are situated in proximity to the cervical pedicle, engendering a significant risk of damage to these structures during CPS insertion. Here, we report a case of cervical posterior instrumentation surgery using a patient-specific three-dimensional (3D) screw guide templating system approved for the cervical spine (Myspine Cervical®). A 62-year-old man presented to our hospital with progressive numbness and paresthesia in both hands and fingers, as well as gait disturbance, which had persisted for one year. A neurological examination revealed severe myelopathy. Imaging findings showed severe spinal cord compression due to ossification of the posterior longitudinal ligament (OPLL) from C3/4 to C6/7. On the diagnosis of compression myelopathy due to cervical OPLL, we performed a posterior decompression and fusion surgery using a patient-specific 3D screw guide templating system (Myspine Cervical®). No severe complications occurred during the surgery. Evaluation of the CPS position by postoperative CT showed that all the CPS placements were accurate. The implementation of the patient-specific 3D screw guide templating system facilitated the secure and precise insertion of CPS in comparison to other surgical assist devices.

Comparing Bone Fusion Rates Between Novel Unidirectional Porous Tricalcium Beta-Phosphate and Autologous Bone in Lumbar Lateral Interbody Fusion: A Two-Year Radiographic Outcome Study.

This retrospective cohort study aims to examine the potential differences in bone fusion between autologous bone and artificial bone in the lumbar lateral interbody fusion at 2two years post-surgery. The bone fusions performed in 15 cases and at 34 intervertebral levels were compared to assess the differences between the artificial bone, Affinos® (Kuraray Co., Tokyo, Japan), and autogenous bone. Two years post-surgery, we evaluated computed tomography (CT) multi-planar reconstruction images in the coronal and sagittal planes. One year after surgery, out of the 24 windows, 17 (70.8%) windows transplanted with autologous bones showed bone fusion. Additionally, out of the 38 windows, 18 (47.4%) windows transplanted with Affinos® showed bone fusion. Two years post-surgery, out of the 24 windows, 19 (79.2%) windows transplanted with autologous bones showed bone fusion. Additionally, out of the 38 windows, 30 (79.0%) windows transplanted with Affinos® showed bone fusion, and no difference was observed in the fusion rate at two years post-surgery (P = 0.238). In cases using Affinos® for transplanted bone, the bone fusion rate increased between one and two years. The rate of bony fusion using Affinos® in lateral lumbar interbody fusion (LLIF) cages is at par with that of autologous bone grafts at two years post-surgery. Affinos® is a promising candidate for graft material in LLIF surgery.

Effect of platelet-rich plasma on the acceleration of graft bone catabolism in lateral lumbar interbody fusion in a short-term assessment.

This study aimed to demonstrate whether impregnating the graft bone with platelet-rich plasma (PRP) accelerates graft bone catabolism in lateral lumbar interbody fusion (LLIF). Consecutive patients who underwent LLIF were assessed. Of the two spaces for bone grafts in the intervertebral cage, one space was filled with graft bone impregnated with PRP, and the other was filled with graft bone without PRP, which divided the graft bones into PRP and non-PRP groups. The mean Hounsfield units (HU) of the graft bone at the center of the cage space in the coronal and axial slices were measured using computed tomography (CT) images 1 week and 6 months after surgery. The delta value of HU from 1 week to 6 months after surgery was calculated for the PRP and non-PRP groups. We compared the delta values of the HU between the two groups. The PRP and non-PRP groups comprised 16 bone grafts. In the coronal slices, the HU value in the PRP group (delta value: 526.1 ± 352.2) tended to have a greater decrease at 6 months after surgery compared with that in the non-PRP group (delta value: 217.6 ± 240.4) (p = 0.065). In the axial slices, the HU value in the PRP group (delta value: 501.3 ± 319.6) was significantly decreased at 6 months after surgery compared with that in the non-PRP group (delta value: 159.2 ± 215.3) (p = 0.028). Impregnating the graft-bone with PRP accelerated graft bone catabolism in LLIF within 6 months after surgery.

Posterior Decompression and Fixation for Thoracic Spine Ossification: A 10-Year Follow-Up Study.

Ossification of the posterior longitudinal ligament of the thoracic spine (T-OPLL) causes symptoms including leg and back pain, and motor and sensory deficits. This study retrospectively reviewed 32 patients who initially underwent posterior decompression with instrumented fusion (PDF) for T-OPLL between 2001 and 2012, with 20 qualifying for the final analysis after applying exclusion criteria. Exclusions included unknown preoperative neurological findings, follow-up less than 10 years, or prior spinal surgeries at other levels. Outcomes were assessed using the Japanese Orthopedic Association (JOA) score, recovery rate, and kyphotic angle. The average preoperative JOA score of 3.6 improved to 7.4 at 1 year post-surgery and remained at 7.4 at 10 years, with a recovery rate of 52%. The kyphotic angle at T4-12 increased from 26 degrees preoperatively to 29 degrees postoperatively and to 37 degrees at 10 years. At the fused levels, the angle remained at 26 degrees immediately post-operation and increased to 32 degrees at 10 years. Forty percent of patients required additional surgery, primarily for conditions related to cervical OPLL, such as myelopathy, or lumbar OPLL, such as radiculopathy, or cauda equina syndrome. In conclusion, PDF effectively reduces T-OPLL symptoms over the long term, but the high rate of additional surgeries calls for careful patient follow-up.