Optimal Intermittent Administration Interval of Abaloparatide for Bone Morphogenetic Protein-Induced Bone Formation in a Rat Spinal Fusion Model.

Both bone morphogenetic protein 2 (BMP-2) and abaloparatide are used to promote bone formation. However, there is no consensus about their optimal administration. We investigated the optimal administration theory for the pairing of BMP-2 and abaloparatide in a rat spinal fusion model. Group I was only implanted in carriers and saline. Carriers with 3 µg of recombinant human BMP-2 (rhBMP-2) were implanted in other groups. Abaloparatide injections were administered three times a week for group III (for a total amount of 120 µg/kg in a week) and six times a week for group IV (for a total amount of 120 µg/kg in a week) after surgery. They were euthanized 8 weeks after the surgery, and we explanted their spines at that time. We assessed them using manual palpation tests, radiography, high-resolution micro-computed tomography (micro-CT), and histological analysis. We also analyzed serum bone metabolism markers. The fusion rate in Groups III and IV was higher than in Group I, referring to the manual palpation tests. Groups III and IV recorded greater radiographic scores than those in Groups I and II, too. Micro-CT analysis showed that Tbs. Sp in Groups III and IV was significantly lower than in Group I. Tb. N in Group IV was significantly higher than in Group I. Serum marker analysis showed that bone formation markers were higher in Groups III and IV than in Group I. On the other hand, bone resorption markers were lower in Group IV than in Group I. A histological analysis showed enhanced trabecular bone osteogenesis in Group IV. Frequent administration of abaloparatide may be suitable for the thickening of trabecular bone structure and the enhancement of osteogenesis in a rat spinal fusion model using BMP-2 in insufficient doses.

Effectiveness of gelatin matrix with human thrombin for reducing blood loss in palliative decompressive surgery with posterior spinal fusion for metastatic spinal tumors.

BACKGROUND: This study aimed to investigate the effect of gelatin matrix with human thrombin (GMHT) on blood loss and survival time in patients with metastatic spinal tumors treated with palliative decompression surgery with posterior spinal fusion. METHODS: We retrospectively reviewed 67 consecutive patients with metastatic spinal tumors who underwent palliative decompression surgery with posterior spinal fusion. We compared patients in whom GMHT was not used during surgery with those in whom GMHT was used. The following baseline characteristics were evaluated: age, height, weight, sex, metastatic tumor diagnosis, medical history, use of antiplatelet drug, use of anticoagulant drug, use of NSAIDs, smoking, preoperative PLT value, preoperative APTT, preoperative PT-INR, Karnofsky Performance Status score, Charlson comorbidities index score, the percentage of patients who received perioperative chemotherapy, main tumor level, Frankel category, revised Tokuhashi score, spinal instability neoplastic score (SINS), number of fusion segments, operation time, intraoperative blood loss, drainage blood loss, red blood cell transfusion, hemoglobin level, total protein (TP), albumin values, total blood loss (TBL), hidden blood loss, postoperative bed rest and postoperative survival time. Perioperative complications were assessed. RESULTS: Age, height, weight, sex, metastatic tumor diagnosis, medical history, use of antiplatelet drug, use of anticoagulant drug, use of NSAIDs, smoking, preoperative PLT value, preoperative APTT, preoperative PT-INR, CCI score, main level of tumors, SINS score, preoperative Tokuhashi score and number of fusion segments did not differ significantly between the two groups. Operation time, intraoperative blood loss, postoperative drainage blood loss, and TBL were significantly decreased in the group with GMHT than in the group without GMHT. The total number of perioperative complications was significantly lesser in the group with GMHT than in the group without GMHT. The median postoperative survival time was significantly longer in the GMHT group than in the group without GMHT. CONCLUSION: GMHT should be considered a valid option for the treatment of patients with metastatic spinal tumors with a short life expectancy.

Efficacy of gelatin-thrombin matrix sealants for blood loss in single-level transforaminal lumbar interbody fusion.

Although gelatin-thrombin matrix sealants have been used successfully in other surgery types, their effect on reducing blood loss during single-level transforaminal lumbar interbody fusion is unclear. We thus examined the efficacy of gelatin-thrombin matrix sealants for reducing blood loss during such surgery. We analyzed 102 patients who underwent single-level transforaminal lumbar interbody fusion for lumbar degenerative disease. We compared body mass index, surgical time, intraoperative blood loss, postoperative blood loss, true total blood loss, hidden blood loss, the proportion of blood transfusion, blood pressure pre- and post-surgery (systolic and diastolic), and pre-and post-surgery laboratory data (hemoglobin, hematocrit, platelets, prothrombin time, activated partial thromboplastin time, and D-dimer) between patients in whom gelatin-thrombin matrix sealants were (GTMS group) or were not (control group) used during surgery. One-week postoperative epidural hematoma size was measured using magnetic resonance imaging. The GTMS and control groups included 54 (24 males and 30 females) and 48 patients (19 males and 29 females). Intraoperative, true total, and hidden blood loss; epidural hematoma size; and hospitalization duration were significantly lower in the GTMS than in the control group. Intraoperative blood loss correlated with surgical time (R = 0.523, P = .001), body mass index (R = 0.221, P = .036), and the amount of gelatin-thrombin matrix sealant used (r = -0.313, P = .002). In multivariate linear regression analysis using intraoperative blood loss as the dependent variable, surgical time (standardization coefficient 0.516, P = .001) and amount of gelatin-thrombin matrix sealant used (standardization coefficient -0.220, P = .032) were independently related factors. In our study, the GTMS group had significantly less intraoperative true total and hidden blood loss than did the control group. Thus, use of gelatin-thrombin matrix sealants reduce perioperative blood loss in transforaminal lumbar interbody fusion.

Analysis of accuracy of pedicle screw placement in dysplastic pedicles in adolescent idiopathic scoliosis using the pedicle expansion technique with CT-based navigation.

BACKGROUND: This study aimed to study the accuracy of pedicle screw (PS) insertion into dysplastic pedicles in adolescent idiopathic scoliosis (AIS) comparing cannulated screw using the pedicle expansion technique (PET) versus conventional technique. METHODS: Forty-two AIS patients with 766 PSs were evaluated. In total, 236 screws were inserted into dysplastic pedicles: 138 and 98 screws were inserted using the PET (PET group) and standard technique (conventional group), respectively. Both methods used CT-based navigation to determine the insertion point. In the PET, a rigid ball tip feeler was tapped with a mallet to create an insertion route, a guide wire was passed through the tap, the pedicle was enlarged, and then a cannulated PS with a diameter of 4.35 mm was inserted. Postoperative CT was used to compare the accuracy of PS insertion. RESULTS: In total, 23/236 (9.7%) perforations occurred. Regarding overall perforation, there were six (4.3%) and 17 (17.3%) cases in the PET and conventional group, respectively (P = 0.008). In terms of medial perforation, the PET group (n = 2, 1.4%) was significantly better than the conventional group (n = 7, 7.1%) (P = 0.021). In terms of lateral perforation, the PET group (n = 4, 2.9%) was significantly better than conventional group (n = 10, 10.2%) (P = 0.030). Only grade 1 perforation had occurred in the PET group, whereas grades 2 and 3 perforation occurred in the conventional group. CONCLUSION: Use of the PET with CT-based navigation significantly increased the accuracy and safety of PS insertion in dysplastic pedicles in AIS.

Analysis of rotational deformity correction by lateral lumbar interbody fusion with two-staged anterior-posterior combined corrective fusion surgery for adult degenerative kyphoscoliosis.

The present study is retrospective analysis of consecutively collected data. Lateral lumber interbody fusion (LLIF) is widely used in cases of adult spinal deformities. However, the corrective effects of LLIF cage insertion on the vertebral rotation deformity in the axial plane and the individual effects of LLIF and direct vertebral rotation (DVR) on rotational correction are unclear. To individually examine the corrective effects of LLIF and posterior corrective fusion surgery with direct DVR on vertebral rotation deformities in adult degenerative kyphoscoliosis. We analyzed 21 patients (5 males and 16 females) who underwent two-staged anterior-posterior combined corrective fusion surgery for adult degenerative kyphoscoliosis. Surgical time, blood loss, facet joint osteoarthritis (OA) grade, disc degeneration, cage height, vertebral rotational angle, and various X-ray parameters were investigated as evaluation items. The X-ray parameters showed significant postoperative improvements. The mean vertebral rotation angle was 6.4°â€…±â€…5.2° preoperatively, 3.5°â€…±â€…3.3° after LLIF (P = .014, vs preoperative), and 1.6°â€…±â€…1.7° after posterior corrective fusion surgery with DVR (P = .011, vs preoperative). Correlation analysis between the vertebral rotation angle and various measured values revealed that the vertebral rotation angle after LLIF was correlated with the cage height (r = -0.46, P = .032). The vertebral rotation angle after DVR was correlated with the facet joint OA grade (r = -0.49, P = .018) and the wedge angle after posterior corrective fusion surgery with DVR (R = 0.57, P = .006). We conclude that the effects of rotational deformity correction with LLIF cage insertion and additional posterior corrective fixation with DVR can be useful for correcting vertebral rotation deformities.

Analysis of treatment effect with teriparatide on device-related vertebral osteopenia after lumbar spinal interbody fusion using Hounsfield unit values: A retrospective cohort study.

The aim of the present study was to investigate the effect of teriparatide on device-related vertebral osteopenia after single lumbar spinal interbody fusion and compare osteopenia in fused and nonfused spinal segments using Hounsfield unit (HU) values. The present study was a retrospective cohort study. We reviewed 68 consecutive patients (28 men and 40 women) who underwent single-segment (L4-5) transforaminal lumbar interbody fusion with cage and pedicle screw fixation. The patients were divided into 2 groups according to whether they were treated with teriparatide (teriparatide and nonmedication groups). The primary outcome measure was HU values measured on computed tomography images from each L1 to S1 vertebral body12-month postoperatively. Secondary outcome measures were femoral neck bone mineral density (BMD), T-score, osseous union, and clinical outcomes using the Japanese Orthopedic Association scoring system 12-month postoperatively. There were significant decreases in HU values of lumbar vertebral bodies at all levels and BMD and T-score values obtained using dual-energy X-ray absorptiometry of the femur between preoperative and postoperative 12-month computed tomography in the nonmedication group (P < .05). On the other hand, there were no significant differences between properative and postoperative 12-month HU values of each lumbar vertebral body and BMD values of the femur in the teriparatide group. Osseous fusion scores in the teriparatide group were significantly better than those in the nonmedication group. There were no significant differences in postoperative Japanese Orthopedic Association scores between the 2 groups. Administration of teriparatide during the perioperative period may prevent bone loss associated with spinal fusion surgery.

Analysis of the risk factors for increasing cervical sagittal vertical axis after cervical laminoplasty for cervical spondylotic myelopathy.

INTRODUCTION: The cervical sagittal vertical axis (cSVA) as another aspect of cervical alignment been recognized as one of the important factors affecting the pain and disability outcomes of cervical spine surgery. The purpose of the present study was to analyze the risk factors for increasing cSVA after cervical laminoplasty for cervical spondylotic myelopathy (CSM). MATERIALS AND METHODS: This retrospective study included 110 consecutive patients (68 males and 42 females, average age 72.6 years) who underwent laminoplasty for CSM between January 2007 and June 2018. We recorded the operative time, blood loss, Japanese Orthopaedic Association (JOA) score and the recovery rate. Radiological measurements were performed to analyze the following parameters: pre- and 1-year postoperative McGregor's slope (McGS), occiput to C2 Cobb angle (O-C2 angle), C2-C7 Cobb angle (C2-7 angle), T1-slope (T1S), C2-7 SVA (cSVA) and calculated the change (Δ). Patients were divided into two groups according to whether ΔcSVA was positive or negative. We also used Spearman's correlation coefficient and multiple regression analysis. RESULTS: ΔC2-7 angle, ΔT1S-preoperative C2-7 angle, ΔO-C2 angle were different between the two groups significantly. Correlation analysis between the ΔcSVA and the various sagittal parameters showed some independent explanatory factors including the ΔC2-7 angle (r = - 0.25, p = 0.010), T1S-preoperative C2-7 angle (r = - 0.28, p = 0.004), postoperative O-C2 angle (r = 0.26, p = 0.007), ΔO-C2 angle (r = 0.37, p = 0.001). Multiple regression analysis revealed that ΔcSVA was associated with the T1S-preoperative C2-7 angle (ß = - 0.25, p = 0.034) and ΔO-C2 angle (ß = 0.32, p = 0.001). CONCLUSIONS: The imbalance between T1S and preoperative C2-7 angle influences the change of cSVA after cervical laminoplasty. If cSVA increases postoperatively, the O-C2 angle increases to compensate and maintain the horizontal gaze.

Successful treatment of left subclavian artery penetration due to ingestion of a safety pin by an elderly person.

BACKGROUND: Ingestion cases are increasing in elderly persons. Herein, we report a rare case of ingestion of a safety pin by an elderly person. CASE PRESENTATION: The patient was an 87-year-old bedridden woman who had fever with left pleural effusion. Chest X-ray revealed a foreign body, confirmed to be a safety pin, in the cervical esophagus. A contrast multidetector row computed tomography scan revealed that the opened safety pin penetrated the left subclavian artery, leading to the diagnosis of an esophageal foreign body penetrating the left subclavian artery. The safety pin was removed, and the subclavian artery aneurysm caused by the penetration was embolized by interventional radiology. After treatment, she was returned to the nursing home on postoperative day 8. CONCLUSION: Penetration by ingestion of a safety pin is rare; in this case, safe treatment was possible due to a team of certified specialist physicians and surgeons.

Analysis of reciprocal changes in upper cervical profiles after posterior spinal fusion with the simultaneous double rod rotation technique for adolescent idiopathic scoliosis.

BACKGROUND: The relationship between postoperative change of cervical lordotic alignment and restoration of thoracic kyphosis with adolescent idiopathic scoliosis (AIS) is still controversial. We investigated reciprocal changes in the sagittal profiles of the upper and middle-lower cervical spinal segments after posterior spinal fusion with the simultaneous double rod rotation technique (SDRRT) for AIS. HYPOTHESIS: Occiput-C2 and C2-C7 sagittal profiles of patients with AIS could change significantly after surgical adequate increase of thoracic kyphosis with SDRRT. PATIENTS AND METHODS: Twenty-seven consecutive patients with AIS treated with the SDRRT were retrospectively reviewed. We investigated the following parameters preoperatively, postoperatively, and at the 2-year follow-up: the Cobb angles of main thoracic curves; C7 sagittal vertical axis; thoracic kyphosis (TK) from T5 to T12; lumbar lordosis from L1 to S1; chin-brow vertical angle; McGregor's slope; occiput to C2 Cobb angle (O-C2angle); C2-C7 Cobb angle (C2-C7angle); T1-slope; and C2-C7 sagittal vertical axis. Additionally, the Scoliosis Research Society questionnaire was completed preoperatively and at the 2-year follow-up. Patients were categorized according to preoperative TK (T5-T12) into hypokyphotic (TK<20°) and normo-hyperkyphotic (TK≧20°) groups. To assess the effect of corrective surgery on sagittal profiles, we investigated correlations among the changes in sagittal parameters. RESULTS: The mean preoperative TK was 6.1±3.7° in the Hypokyphotic group and 23.5±4.7° in the Normo-hyperkyphotic group (p<0.001), which was significantly improved postoperatively (22.3±4.4° and 26.1±2.6°, respectively; p=0.02) and at the 2-year follow-up (23.0±6.3° and 26.8±5.0°, respectively; p=0.04). The mean preoperative C2-C7angle reflected kyphosis (7.4±9.8°) in the Hypokyphotic group, and, in contrast, lordosis (-8.8±6.8°) in the Normo-hyperkyphotic group (p<0.001), which improved toward greater lordosis postoperatively (-3.7±5.8° and -14.8±5.1°, respectively; p<0.001) and at the 2-year follow-up (-5.1±4.4° and -15.3±6.4°, respectively; p<0.001). On the other hand, the mean preoperative O-C2angle was -20.5±6.5° in the Hypokyphotic group and -13.1±2.8° in the Normo-hyperkyphotic group (p=0.002), which was significantly changed postoperatively (-12.6±6.4° and -7.7±4.3°, respectively; p=0.04) and at the 2-year follow-up (-13.1±6.3° and -7.9±4.3°, respectively; p=0.04). ΔC2-C7 was negatively correlated with ΔT5-T12 (r=-0.298) and ΔO-C2angle (r=-0.332). DISCUSSION: Lordotic reciprocal alignment changes in the C2-C7angle can occur after adequate restoration of TK. The O-C2angle compensates the C2-C7angle for a maintained horizontal gaze. O-C2 and C2-C7 sagittal profiles of patients with AIS changed significantly after corrective surgery with SDRRT. LEVEL OF EVIDENCE: IV, Case-series.

Analysis of computed tomography-based infra-acetabular morphometry to assess the feasibility of infra-acetabular screws.

INTRODUCTION: The number of pelvic fractures based on osteoporosis has been increasing. The infra-acetabular screw (IAS), which connected both osseous columns, is a safe method of screw placement going through the infra-acetabular corridor (IAC). However, the specifics of the anatomy of IAC have been far from completely understood, especially in the Asian population. The purpose of our study was to reveal the details of the IAC using computed tomography (CT) data. MATERIALS AND METHODS: Traumatized in-patients having pelvic CT scans from 2014 to 2016 were enrolled. Pediatric and adult patients with pelvic fractures and hip prostheses were excluded. The male/female ratio and distribution of patients' age were equalized manually; 40 male and 40 female patients were included. The IAC was measured on the plane of the inlet view (25° caudal) in multi-planar reconstructed CT images. MEASUREMENTS: infra-acetabular diameter (IAD), anterior-posterior length of the IAC (APL), length from the starting point of the IAC to the medial edge of the pelvis (LME), length from the starting point of the IAC to the top of the pubic symphysis (LPS), and tilting on inlet plate (TIP). RESULTS: Age was 59 ± 22 (mean ± SD). Height was 159 ± 11 cm, and body mass index (BMI) was 22.9 ± 4.1. IAD, APL, LME, LPS, and TIP was 4.0 ± 1.3 mm, 89.5 ± 7.1 mm, 8.7 ± 3.6 mm, 57.8 ± 4.8 mm, and 4.7 ± 5.2°, respectively. Over 20% of corridors (35 of 160) were not feasible for IAS placement, because of inadequate width (less than 3.0 mm). Nine corridors (5.6%) had curvature in IAC, which meant technically demanding to insert IAS. There was no difference in IAD between male and female patients, while APL, LME, LPS, and TIP had sex-related differences. CONCLUSIONS: Surgeons should pay attention to the fact that over 20% of IACs are not feasible for infra-acetabular screw placement even with the perfect reduction of fragments when treating acetabular fractures.

Cervical alignment after single-level anterior cervical corpectomy and fusion using autologous bone graft without spinal instrumentation for cervical pyogenic spondylitis.

BACKGROUND: Subsidence in anterior cervical corpectomy and fusion (ACCF) for cervical degenerative disease (CDD) are constantly observed during the postoperative course. Although kyphotic change of cervical alignment occurred frequently in cervical pyogenic spondylitis (CPS) postoperatively, studies on the postoperative change in segmental angle for CPS are limited. This study aimed to analyze cervical alignment after single-level ACCF using autologous bone graft without spinal instrumentation for CPS compared with that for CDD. METHODS: Six patients underwent single-level ACCF using autologous bone graft without spinal instrumentation for CPS. The control group included 18 age-matched patients who underwent single-level ACCF using autologous bone graft for CDD without spinal instrumentation for the same duration. Cervical and lateral plain radiographs and computed tomography scans were taken. The Frankel classification was used to assess the neurological status preoperatively, postoperatively, and at 2-year follow-up for CPS. RESULTS: At 2-year follow-up, the average segmental angle at the fusion level was - 12.2° ± 6.9° for CPS and - 5.2° ± 7.6° for CDD (p = 0.04). Changes in segmental angle at the fusion level were - 7.2 ± 9.0° for CPS and - 1.1° ± 7.1° for CDD (p = 0.02). At 2-year follow-up, the average anterior segmental fusion height was 23.4 ± 1.7 mm for CPS and 29.1 ± 5.1 mm for CDD (p < 0.001). At 2-year follow-up, bone fusion in the CPS group was classified as grade 5 (complete fusion) in 4 patients (66.7%) and grade 4 (probable fusion) in 2 (33.3%). In the CDD group, it was grade 5 in 13 patients (72.2%) and grade 4 in 5 patients (27.8%). Overall, both groups achieved 100% bone fusion rate. The Frankel classification in all CPS cases improved or leveled off. CONCLUSION: Progression of segmental kyphosis angle and subsidence of graft bone were observed postoperatively on all CPS cases. However, the neurological recovery and bone union were satisfactory.

Enhancement of the effects of intermittent parathyroid hormone (1-34) by bone morphogenetic protein in a rat femoral open fracture model.

BACKGROUND: Nonunion in cases of open fracture is common. Both bone morphogenetic protein 2 (BMP-2) and parathyroid hormone (PTH) have been used to enhance bone healing. We investigated the combination of BMP-2 and PTH and examined the effects on a rat model of open femoral fractures. METHODS: Group I (n = 11) was implanted with control carrier. Group II (n = 12) was implanted with carrier containing 1 µg of recombinant human BMP-2 (rhBMP-2). Group III (n = 12) was implanted with carrier alone, followed by injections of PTH 1-34. Group IV (n = 11) was implanted with carrier containing 1 µg of rhBMP-2, followed by injections of PTH 1-34. Group V (n = 11) was implanted with carrier containing 10 µg of rhBMP-2. Group VI (n = 11) was implanted with carrier containing 10 µg of rhBMP-2, followed by injections of PTH 1-34. Rats were euthanized after 8 weeks, and their fractured femurs were explanted and assessed by manual palpation, radiographs, micro-computerized tomography, and histological analysis. RESULTS: Manual palpation tests showed that the fusion rates of groups III (66.7%), IV (63.6%), V (81.8%), and VI (81.8%) were considerably higher than those of group I. Groups V and VI had higher radiographic scores compared to group I. Micro-CT analysis revealed enhanced bone marrow density expressed as bone volume/tissue volume in groups V (61.88 ± 3.16%) and VI (71.14 ± 3.89%) versus group I (58.26 ± 1.86%). A histological analysis indicated that group VI had enhanced remodeling. CONCLUSION: The combination of abundant rhBMP-2 and PTH enhanced bone healing and remodeling of newly formed bone in a rat femoral open fracture model.

Effect of intraoperative position in single-level transforaminal lumbar interbody fusion at the L4/5 level on segmental and overall lumbar lordosis in patients with lumbar degenerative disease.

The purpose of this study was to investigate the effect of intraoperative positions in single-level (L4-5) transforaminal lumbar interbody fusion (TLIF) on segmental and overall lumbar lordosis (LL) in patients with lumbar degenerative disease. Thirty-eight consecutive patients who had undergone single-segment (L4-5) TLIF with 0° polyetheretherketone (PEEK) cage and pedicle screw fixation were evaluated. Twenty patients underwent surgery on the four-poster type frame with hip flexion at 30° (Group I) and 18 patients were operated on a Jackson spinal table to adjust their hip flexion to 0° (Group II). Preoperative standing, intraoperative prone, and postoperative standing lateral radiographs were obtained in each patient. The overall and segmental LL were analyzed according to the position in which the patients were placed for their operation and results compared between Groups I and II. Intraoperative intervertebral segmental LL at L4-5 and L5-S1 was increased in Group II than in Group I, whereas postoperative intervertebral segmental LL at L4-5 (fused level) was increased LL. In Group I intraoperative intervertebral segmental LL at L4-5 did not achieve sufficient lordosis, whereas postoperative intervertebral segmental LL at L3-4 was increased. The overall spinal alignment was unaffected by the decreased segmental LL in the fused level owing to the compensation of the upper adjacent segments. The more the hip was extended intraoperatively, the more the segmental lordosis increased in the lower lumbar spine. Thus, selecting the appropriate surgical table and hip position are very important. Underachievement of segmental lordosis leads to the acceleration of upper adjacent segment load.

Spinal epidural lipomatosis is associated with liver fat deposition and dysfunction.

OBJECTIVE: This study examined the association of spinal epidural lipomatosis (SEL) with liver fat deposition and any other liver dysfunction, except steroid involvement. PATIENTS AND METHODS: We analyzed 102 patients (62 men and 40 women; mean age 73.3 years) who underwent spinal magnetic resonance imaging (MRI), computed tomography (CT), and myelography for the diagnosis of lumbar spinal canal stenosis between January 2014 and June 2018. Additional data collected included height, weight, body mass index, blood test results (C-reactive protein, albumin, total bilirubin, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase [γ-GTP], total cholesterol, neutral fat, amylase, urea nitrogen, creatinine, estimated glomerular filtration rate, uric acid, platelets), the epidural fat-occupying ratio in each vertebra from L1/2 to L5/S1 on MRI, and liver CT values. RESULTS: In 30 cases, the average occupying ratio of epidural fat was ≥40% (SEL), and in 45 cases, liver CT values were <40 HU (fatty liver). Correlation analysis between average occupying ratio of epidural fat and various measurements showed liver CT value (r = -0.574, P <  0.001), body weight (r = 0.304, P =  0.002), γ-GTP (r = 0.370, P =  0.01), and uric acid (r = 0.201, P =  0.04) to be independent explanatory factors. Multivariate analysis revealed that SEL was associated with liver CT value (odds ratio 0.774, 95% confidence interval [CI] 0.689-0.871) and body weight (odds ratio 1.063, 95% CI 1.016-1.135). CONCLUSION: There was a strong correlation between epidural fat and liver fat deposits suggesting an association between SEL and systemic fat deposition.

Minimally invasive triangular osteosynthesis for highly unstable sacral fractures: Technical notes and preliminary clinical outcomes.

Triangular osteosynthesis involves unilateral L5 iliac posterior instrumentation combined with an iliosacral screw fixation. The aim of this study was to describe this procedure and report the preliminary clinical results in patients with unstable sacral fractures treated with minimally invasive triangular osteosynthesis (MITO). Between 2012 and 2017, 10 patients (6 men and 3 women, mean age, 50 ±â€Š23 years) with sacral fractures were treated with MITO and were followed up for a mean of 15.0 ±â€Š8.5 months in our institution. Classification of sacral fracture, operative time, intraoperative bleeding, timing of full weight bearing, bone union, complications, and clinical outcomes were investigated. Two cases were classified as Denis zone 1, 2 cases as zone 2, and 6 as zone 3. Four patients had Roy-Camille type 1 fracture and 2 patients had type 2. All patients underwent MITO, which involved bilateral lumbopelvic fixation and a uni/bilateral iliosacral screw with stab incisions for percutaneous fixation or central longitudinal incision. The operative time was a mean of 182 ±â€Š64 minutes, and the amount of intraoperative bleeding was a mean of 63 ±â€Š74 g. Full-weight bearing was initiated at a mean of 8.2 ±â€Š2.4 weeks. Eight fractures healed; 1 patient had pulmonary embolism and 1 had implant loosening. Based on Majeed score, 8 patients had "excellent" clinical outcomes, 1 patient had a "good" clinical outcome, and the other had a "fair" clinical outcome. MITO could be less invasive on the soft tissues and be a reliable procedure for bony union. It might provide sufficient stability to accelerate the commencement of post-operative rehabilitation, even in patients with highly unstable sacral fractures.

Relationship of T1 slope with loss of lordosis and surgical outcomes after laminoplasty for cervical ossification of the posterior longitudinal ligament.

OBJECTIVE: T1 slope (T1S) has emerged as a predictor of kyphotic alignment change after laminoplasty. Although it was reported that patients with cervical ossification of the posterior longitudinal ligament (OPLL) and higher T1S had more pronounced lordotic curvature before surgery and higher loss of cervical lordosis after surgery, few studies have attempted to correlate these findings with clinical outcomes. We aimed to investigate the relationship of T1S with loss of cervical lordosis and surgical outcomes after laminoplasty for cervical OPLL. PATIENTS AND METHODS: 35 consecutive patients (26 men and 9 women) with cervical OPLL who underwent double-door laminoplasty were followed for more than 12 months. Radiological and clinical measurements were performed to analyze the following parameters: pre and postoperative C2-C7 Cobb lordotic angle (LA), preoperative C2-C7 range of motion (ROM), loss of cervical lordosis, percentage of change in postoperative kyphosis, pre and postoperative C2-C7 sagittal vertical axis (SVA), change in C2-C7 SVA and occupying ratio of the OPLL, Japanese Orthopedic Association (JOA) score recovery rate, preoperative MRI grade. RESULTS: Patients were divided into 2 groups according to preoperative T1 slope, with the cutoff value being the average preoperative T1 slope. Preoperative C2-C7 Cobb LA (P=0.007) and loss of cervical lordosis (P=0.034) differed between the two groups. Preoperative C2-C7 Cobb LA (R=0.50, P=0.002) and loss of cervical lordosis (R=0.36, P=0.036) were significantly correlated to preoperative T1S. Multivariate linear regression analysis showed that the preoperative T1S was not related to JOA score recovery rate and the preoperative MRI grade (OR=-9.985, P=0.015) was only related to JOA score recovery rate. CONCLUSION: Although the degree of alignment compromise is correlated with the preoperative T1S, clinical outcomes demonstrate overall improvement after cervical laminoplasty with cervical OPLL, regardless of preoperative T1S.

Spondylectomy and lateral lumbar interbody fusion for thoracolumbar kyphosis in an adult with achondroplasia: A case report.

RATIONALE: Fixed thoracolumbar kyphosis with spinal stenosis in adult patients with achondroplasia presents a challenging issue. We describe the first case in which spondylectomy and minimally invasive lateral access interbody arthrodesis were used for the treatment of fixed severe thoracolumbar kyphosis and lumbar spinal canal stenosis in an adult with achondroplasia. PATIENT CONCERNS: A 61-year-old man with a history of achondroplastic dwarfism presented with low back pain and radiculopathy and neurogenic claudication. DIAGNOSES: Plain radiographs revealed a high-grade thoracolumbar kyphotic deformity with diffuse degenerative changes in the lumbar spine. The apex was located at L2, the local kyphotic angle from L1 to L3 was 105°, and the anterior area was fused from the L1 to L3 vertebrae. MRI revealed significant canal and lateral recess stenosis secondary to facet hypertrophy. INTERVENTIONS: We planned a front-back correction of the anterior and posterior spinal elements. We first performed anterior release at the fused part from L1 to L3 and XLIF at L3/4 and L4/5. Next, the patient was placed in the prone position. Spondylectomy at the L2 vertebra and posterior fusion from T10 to L5 were performed. Postoperative radiographs revealed L1 to L3 kyphosis of 32°. OUTCOMES: No complications occurred during or after surgery. Postoperatively, the patient's low back pain and neurological claudication were resolved. No worsening of kyphosis was observed 24 months postoperatively. LESSONS: Circumferential decompression of the spinal cord at the apical vertebral level and decompression of lumbar canal stenosis were necessary. Front-back correction of the anterior and posterior spinal elements via spondylectomy and lateral lumbar interbody fusion is a reasonable surgical option for thoracolumbar kyphosis and developmental canal stenosis in patients with achondroplasia.

Surgical outcomes after laminoplasty for cervical spondylotic myelopathy: A focus on the dynamic factors and signal intensity changes in the intramedullary spinal cord on MRI.

OBJECTIVE: We aimed to analyze the relationship between the dynamic factors and signal intensity changes in the intramedullary spinal cord on MRI, and surgical outcomes, following double-door laminoplasty for cervical spondylotic myelopathy (CSM). PATIENTS AND METHODS: This retrospective study included 100 consecutive patients who underwent double-door laminoplasty for CSM. The following factors were analyzed: JOA score recovery rate, age, duration from onset to surgery, intraoperative bleeding, signal intensity changes in the intramedullary spinal cord on MRI, pre and postoperative C2-7 lordotic angle (LA), changes in C2-7 LA, pre and postoperative C2-7 range of motion (ROM), and pre and postoperative segmental ROM. The Charlson Comorbidity Index (CCI) was also used for the assessment of complications. RESULTS: Age, CCI, preoperative segmental ROM, and pre and postoperative MRI grade significantly correlated with JOA score recovery rate (P<0.01), whereas number of expanded laminae, duration from onset to surgery, surgery time, intraoperative bleeding, preoperative and postoperative C2-7 LA, change in C2-7 LA, and preoperative C2-7 ROM did not. Multivariate analysis showed that the preoperative segmental ROM (OR=-0.988, P=0.017) and preoperative MRI grade (OR=-7.170, P=0.042) were significantly associated with JOA score recovery rate. CONCLUSION: Considering the dynamic factors, there was no correlation with C2-7 ROM and surgical outcome, but preoperative segmental ROM and a change in signal intensity of the intramedullary spinal cord on MRI were negatively correlated with surgical outcome. From these results, we suggest that preoperative segmental ROM is possibly associated with spinal cord damage due to repeated minor trauma and affects surgical outcome of laminoplasty.

Surgical outcomes of laminoplasty for cervical spondylotic myelopathy in very elderly patients (older than 80 years): Time from symptom onset to surgery and changes in spinal cord signal intensity on MRI.

OBJECTIVE: We aimed to assess the surgical outcomes of laminoplasty for cervical spondylotic myelopathy (CSM) in very elderly patients (older than 80 years), focusing specifically on the time from symptom onset to surgery and on the loss in spinal cord signal intensity on magnetic resonance imaging (MRI). PATIENTS AND METHODS: We retrospectively reviewed 100 consecutive patients (61 males and 39 females) with CSM who underwent laminoplasty between 2006 and 2014. The patients were stratified based on the age at the time of surgery, with Group A consisting of 26 patients aged 80 years or older and Group B consisting of 74 patients younger than 80 years. The severity of myelopathy was assessed in terms of the Japanese Orthopaedic Association (JOA) score. Signal intensity loss on MRI was graded from I to III based on the size of the area with intensity changes (Grade I, one disk; Grade II, larger than one disk) and presence of intramedullary hypointensity on T1-weighted sagittal scans (Grade III). Surgical outcome, morbidities, and changes in spinal cord signal intensity on MRI were analyzed. RESULTS: The time from symptom onset to surgery was 6.2±5.2 and 16.5±18.8months in Groups A and B, respectively, with significantly shorter duration of symptoms in Group A (p<0.001). Compared to Group B, Group A had lower mean JOA score preoperatively (8.8±1.9 vs. 10.1±1.7) and postoperatively (12.1±1.7 vs. 13.5±1.6), as well as lower mean JOA score recovery rate (40.7±12.5% vs. 51.0±15.4%) (p<0.05 for all). However, there was no difference between the groups regarding achieved JOA score (Group A, 3.3±1.0; Group B, 3.4±1.0). Preoperatively, intramedullary signal intensity change was observed in 84.6% of patients in Group A (22/26; 3, 13, and 6 patients with Grade I, II, and III, respectively), and in (82.4%) of patients in Group B (61/74; 18, 38, and 5 patients with Grade I, II, and , respectively), with significantly higher incidence of Grade III pattern in Group A than in Group B. CONCLUSION: Compared to younger patients, very elderly patients had a shorter time from symptom onset to surgery but lower preoperative JOA score, indicating that the condition of very elderly patients is likely to deteriorate and become severe rapidly after the onset of myelopathy. However, it is very important to know these pathologies and optimize the timing of surgery, as laminoplasty for CSM can be beneficial even in very elderly patients.

Surgical management of ventrally located spinal meningiomas via posterior approach.

BACKGROUND: Spinal meningioma is a relatively common tumor among intradural extramedullary spinal tumors. When the locus of the meningioma is located on the ventral side, tumor removal, dura mater resection, and reconstruction via a posterior approach safety become technically difficult. METHODS: Twelve patients, who received surgical treatment for ventral spinal meningioma via a posterior approach, were included. There were three male and nine female patients, with an average age of 66.3 years (47-88 years). The average observation period was 55.4 months (22-132 months). In these cases, we analyzed the spinal level of tumor position, histopathological type (subtype), the grade of tumor resection (Simpson grade), pre- and post-operative walking state (Nurick grade), perioperative neurological complications, and the recurrence. RESULTS: Spinal meningioma occurred in the cervical spinal cord in three cases, with a further nine cases in the thoracic spinal cord. Histopathologically, all 12 tumors were assessed as grade I on the WHO classification system (eight cases of meningothelial type and four cases of psammomatous type). The level of tumor resection was Simpson grade I resection for two cases and Simpson grade II resection for the remaining ten cases. The average of Nurick grade improved from 3.3 preoperatively to 1.3 postoperatively. In all cases, we identified no neurological complications. One incident of tumor recurrence was identified 11 years after an operation involving a Simpson grade II resection CONCLUSION: Posterior approaches provide adequate exposure to safely remove ventrally located meningioma. Posterior exposures with lateral bone resection, dentate ligament division, provide also adequate exposure for safe removal.