Low back pain has several etiologies. Appropriate treatment should be selected following the etiology and pathology of the pain. Various pharmacotherapeutic options are available for low back pain, and many systematic reviews have been published on the efficacy and safety of the different available pharmacotherapies. However, these reports were mostly based on the evidence from placebo-controlled randomized controlled trials, and their conclusions may not necessarily be consistent with the outcomes observed in actual clinical practice; therefore, we conducted a comprehensive narrative review of the existing evidence on the efficacy or effectiveness of pharmacotherapies for low back pain and sciatica. This narrative review was performed by systematically collecting the relevant literature, including recent active-controlled randomized controlled trials and observational studies. The evidence obtained in this review conformed to the recommendations of the current guidelines for low back pain; however, given that the evidence seemed insufficient for some pharmacotherapies, a continued accumulation of evidence and knowledge is warranted. We hope that this review paper will help clinicians and spine surgeons select appropriate medications on the basis of the pathology of the patient's pain.

Introduction: Postoperative new neurologic defects are one of the complications to avoid regarding spinal cord surgery. This study aimed to observe: 1) waveform changes and postoperative neurologic deficits in multimodal intraoperative neuromonitoring (IONM) and 2) the effects of the interventions performed in response to these events.

Methods: This retrospective study included 272 patients who underwent adult spinal deformity surgery with multimodal IONM from April 2016 to September 2020. Transcranial motor evoked potentials (TcMEP), free-run electromyography (fEMG), short latency somatosensory evoked potentials (SSEP), timing of alerts, and interventions at waveform changes were reviewed. All the patients were reassessed for new neurologic deficits during the postoperative period and followed up based on the intraoperative findings and neurologic deficits.

Results: Of the 272 patients being monitored continuously during the intraoperative period, 22 of TcMEP, 5 of fEMG, 30 of TcMEP and fEMG, and 1 of TcMEP and SSEP showed alerts. The interventions included interruption of surgical operation, decompression, removing the rod, adjusting the anesthesia, increasing the blood pressure, and blood transfusion. Of the 30 patients (11 of TcMEP, 1 of TcMEP and SSEP, 18 of TcMEP and fEMG) whose IONM showed waveform change even after bailout intervention, postoperative neurologic deficits were seen in 17 of the 30 (56.7%) patients (6.3% of all the cases). The multimodal IONM used in this study had a sensitivity of 100%, specificity of 92.9%, positive predictive value of 48.6%, and negative predictive value of 100%.

Conclusions: Postoperative new neurologic deficits may be avoided via appropriate alerts and interventions using multimodal IONM.

Introduction: Since 2008, we have consistently performed manual screw insertion using a ball tip probe for adolescent idiopathic scoliosis. We compared the perforation rates between the initial 50 cases performed by a single surgeon at the time of introduction of the thoracic pedicle screw and the latest 50 cases performed by his 4 junior orthopedic associates.

Methods: Of the 804 AIS patients who underwent surgery from January 2008 to January 2019, 100 patients were classified as Lenke 1. There are the initial 50 cases operated by one skilled surgeon (group A) and latest 50 cases operated by his 4 junior associates (group B). The insertion was performed by a freehand technique using a ball tip probe, and the insertion position was evaluated by a postoperative CT axial image. The direction of deviation was classified into inner, outer, and front, and the degree of deviation was graded. The perforation rate between the two groups were compared.

Results: The deviation rate is 3.6% in groups A and 3.4% in group B. In addition, no serious complications of nerve or vascular injury due to the deviation screw was observed.

Conclusions: The insertion technique of pedicle screw for thoracic spine using the freehand technique is comparable to pedicle insertion with navigation from a safety perspective and is much better from a cost performance perspective.

Introduction: Dysphagia is one of the most serious complications after anterior cervical decompression and fusion (ACDF) surgeries; however, there are few reports on the risk factors that lead to this complication. The purpose of this study was to clarify the risk factors of dysphagia after ACDF.

Methods: A total of 802 patients who underwent ACDF at our institution participated in the study. Patients who needed intravenous or tube feeding > 2 days after the third day were classified under the dysphagia (D) group. We compared sex, age, diagnosis, operative levels, C2 involvement, operative time, blood loss, and cerebrospinal fluid (CSF) leakage between D and no dysphagia (N) groups.

Results: Dysphagia was recognized in 21 of 802 patients. The D group had higher age, ossification of the posterior longitudinal ligament (OPLL) ratio, operative levels, C2 involvement, longer operative time, more bleeding, and more CSF leakage than the N group. Furthermore, multivariable analysis revealed that high age and C2 involvement were independent risk factors.

Conclusions: We found high age, OPLL ratio, multilevel surgery, C2 involvement, longer operative time, high bleeding, and CSF leakage to be risk factors of dysphagia after ACDF surgery. High age and C2 involvement were the most important factors among them.

Introduction: For severe cases of pyogenic spondylitis, we adhered to surviving sepsis campaign guidelines and performed orthopedic interventions with clear objectives and appropriate timing. We investigated the clinical factors and outcomes.

Methods: Twenty-seven consecutive patients with severe pyogenic spondylitis with extra-vertebral abscesses treated at the Emergency Center of Tohoku University Hospital over for 10 years from April 2008 were included in this study. From the electronic medical records, we investigated the diagnosis and treatment details, imaging findings, compliance with guidelines, and outcome.

Results: All patients were initially treated in compliance with the guidelines, and the causative organism was identified for all case except one. Puncture and/or curettage of the lesion for eradication of infection was performed in 25 patients (93%), and surgery was performed in 18 patients (67%); 1 patient died, and 26 patients survived (5 patients were discharged home and 21 patients were transferred to another hospital).

Conclusions: The comprehensive treatment strategy for severe pyogenic spondylitis of our institution was presented and the clinical outcomes were reported.

Introduction: Lower cervical spine fracture-dislocations may cause severe paralysis and have a significant influence on daily life and function. Various reports have evaluated factors involved in the improvement of paralysis. This study aimed to reveal the factors involved in the improvement of paralysis in surgically treated patients for lower cervical spine fracture-dislocations.

Methods: Fifteen patients who underwent surgery after the diagnosis of lower cervical spine fracture-dislocations, and would be available for follow-ups for more than 6 months, were classified into two groups, one with improved paralysis and the other without paralysis improvement. Age, time from injury to reduction, time from injury to surgery, AIS, dislocation distance of injury vertebral bodies, disc spinal canal occupancy, and SLIC score were compared between the two groups. The mean postoperative follow-up period was 10.5 months (from 6 to 41 months). This study is a retrospective study.

Results: There were 6 patients in the improved group and 9 patients in the nonimprovement group. The only significant difference between the 2 groups was the time from injury to reduction, which was significantly shorter in the paralysis improvement group (p = 0.027). In particular, patients who were able to reduce within 12 hours from injury were significantly more likely to improve their paralysis. There were no significant differences in the other items examined.

Conclusions: Based on the results of this study, as described in previous reports, it was concluded that early dislocation reduction may improve the prognosis of paralysis.

Introduction: Postoperative cement leakage during Balloon Kyphoplasty (BKP) can lead to serious complications. However, there were no imaging assessment reports to predict the risk of leakage preoperatively. This study investigated whether the risk of cement leakage after BKP could be predicted by preoperative computed tomography (CT) imaging and postoperative intravascular embolization.

Methods: 81 patients underwent BKP for acute phase osteoporotic vertebral fractures between November 2016 and September 2019. Sugita classification was used for fracture classification. Preoperative CT was used to evaluate the presence of vertebral cortical disruption, and postoperative CT was used to evaluate the presence of cement leakage.

Cement leakage was significantly more frequent in the slipped endplate type than other types (p=0.0072).

Results: The cement leakage group (group L) consisted of 23 patients (28.4%). The percentage of group L in patients with vertebral cortical disruption was 35.6%, significantly higher than in patients without disruption (p=0.015). All cement embolization into the perivertebral venous plexus occurred in the slipped endplate type.

Conclusions: Preoperative CT showed that cement leakage was significantly higher in patients with vertebral cortical disruption. The slipped endplate type may be a risk factor for cement embolization into the blood vessels.

Introduction: In this study, we investigate the cases of osteoporotic vertebral fracture in our hospital.

Methods: This study included 175 cases (37 males and 138 females: 199 vertebral bodies) who were hospitalized with osteoporotic vertebral fractures except for traffic trauma and under 60 years old from January 2018 to September 2020. We investigated the onset age, sex, body mass index, fracture vertebral body height, onset mechanism, past history of fragility fracture, osteoporosis drug, internal medicine consultation, and living environment.

Results: The average onset age was 82.8 years and the average BMI is 21.5. The fracture vertebral body height was T12 42 cases, L1 51 cases, L2 38 cases, and 68 other cases that included multiple fractures. Past history of the fragile fractures were for the spine in 114 cases, femur in 11 cases, and multiple fractures in 8 other. Osteoporosis drugs were PTH in 4 cases, bisphosphonate in 19 cases, SERM in 5 cases, Vitamin D in 22 cases, and 7 other that had concomitant use. Moreover, 156 cases had a medical examination, 153 cases were hospitalized from the home, and 22 cases were hospitalized from the facility. The facility entrance increased by 31 cases at the time of discharge. The overall rate of cases which had taken the osteoporosis drug was 26% (45/175 cases). Additionally, the initial fracture was 11% (6/56 cases) and the existing fracture was 33% (39/119 cases).

Conclusions: The overall rate of cases which had taken the osteoporosis drug was 26% (45/175 cases). In conclusion, patients with bone fragility are prone to an impaired walking ability due to osteoporotic vertebral body fractures. It is necessary to take measures against osteoporosis before injury.

Introduction: Commercially available allogenic fibrin glue is commonly used in daily practice. It is made from pooled human plasma and bovine aprotinin. It, therefore, carries risks of viral infection, allergic reaction, and prion transmission. In contrast, complete autologous fibrin glue (CAFG), made by CryoSeal^® System, has no such risks because it is made from patient's own blood only.

Case Report: We used CAFG in three patients with intradural tumors. Autologous cryoprecipitate and thrombin were extracted from patients' own blood donation and applied on the sutured dura mater with polyglycolic acid sheet after the removal of tumors. One patient had serous discharge from the drain tube and complained of headache immediately after surgery, which got resolved spontaneously. There was no apparent CSF leakage detected on postoperative MRI in all patients.

Conclusions: CAFG is a safe and potent alternative for commercially available allogenic fibrin glue.