Overweight increases perioperative spinal surgery complications: a single-center retrospective study.

BACKGROUND: The World Health Organization (WHO) defines a person with a body mass index (BMI) greater than or equal to 25 kg/m2 as overweight. Being overweight is a lifestyle-related disease; however, little is known about the impact of overweight on the perioperative complications of orthopedic surgery. This study aimed to define the effect of overweight on the perioperative complications of spinal surgery. METHODS: This retrospective case series study reviewed 269 consecutive patients who underwent spinal surgery. These patients were divided into the overweight (OW) and non-overweight (NOW) groups. Age, BMI, surgical time, blood loss, and perioperative complications were evaluated and compared between the groups. RESULTS: There were 117 patients (43%) in the OW group and 152 (57%) in the NOW group. Cervical surgery was performed in 72 cases, thoracic surgery in 34, and lumbosacral surgery in 159. The surgical time was significantly longer in the OW group than in the NOW group (204.6 ± 98 min vs. 175 ± 75 min; p = 0.01). Blood loss was greater in the OW group than in the NOW group (446.8 ± 447.9 mL vs. 279 ± 296.5 mL; p = 0.00). Durotomy was more frequent in the OW group than in the NOW group (10 vs. 3 cases; p = 0.02). There was no difference in complications other than durotomy. CONCLUSIONS: OW patients had longer surgical time, more blood loss, and more frequent durotomy than NOW patients. These findings indicate that overweight increases perioperative complications of spinal surgery.

Vacuum phenomenon as a predictor of kyphosis after implant removal following posterior pedicle screw fixation without fusion for thoracolumbar burst fracture: a single-center retrospective study.

BACKGROUND: Posterior pedicle screw fixation without fusion has been commonly applied for thoracolumbar burst fracture. Implant removal is performed secondarily after bone union. However, the occurrence of secondary kyphosis has recently attracted attention. Secondary kyphosis results in poor clinical outcomes. The purpose of this was to determine predictors of kyphosis after implant removal following posterior pedicle screw fixation without fusion for thoracolumbar burst fracture. METHODS: This retrospective study reviewed 59 consecutive patients with thoracolumbar burst fracture who underwent implant removal following posterior pedicle screw fixation without fusion. Inclusion criteria were non-osteoporotic fracture and T11-L3 burst fracture. Old age, sex, initial severe wedge deformity, initial severe kyphosis, and vacuum phenomenon were examined as factors potentially associated with final kyphotic deformity (defined as kyphotic angle greater than 25°) or loss of correction. Logistic regression analysis was performed using propensity score matching. RESULTS: Among the 31 female and 28 male patients (mean age 38 years), final kyphotic deformity was found in 17 cases (29%). Multivariate analysis showed a significant association with the vacuum phenomenon. Loss of correction was found in 35 cases (59%) and showed a significant association with the vacuum phenomenon. There were no significant associations with other factors. CONCLUSIONS: The findings of this study suggest that the vacuum phenomenon before implant removal may be a predictor of secondary kyphosis of greater than 25° after implant removal following posterior pedicle screw fixation without fusion for thoracolumbar burst fracture, but that old age, sex, initial severe kyphosis, and initial severe wedge deformity may not be predictors.

A Comparative Study on the Minimal Invasiveness of Full-Endoscopic and Microendoscopic Cervical Foraminotomy Using Intraoperative Motor Evoked Potential Monitoring.

Background and Objectives: Full-endoscopic cervical foraminotomy (FECF) and microendoscopic cervical foraminotomy (MECF) are effective surgeries for cervical radiculopathy and are considered minimally invasive in terms of damage to paraspinal soft tissue. However, no studies have quantitatively compared FECF and MECF in terms of neurological invasiveness. The aim of this study was to compare the neurological invasiveness of FECF and MECF using intraoperative motor evoked potential (MEP) monitoring. Materials and Methods: A chart review was conducted of 224 patients with cervical radiculopathy who underwent FECF or MECF between April 2014 and March 2020. Patients were 37 women and 187 men, with a mean age of 51 (range, 21-86) years. FECF was performed in 143 cases and MECF was performed in 81 cases. Results: Average MEP amplitude significantly increased from 292 mV before to 677 mV after nerve root decompression in patients who underwent the FECF. The average improvement rate was 273%. In patients who underwent the MECF, average MEP amplitude significantly increased from 306 mV before to 432 mV after nerve root decompression. The average improvement rate was 130%. The improvement rate was significantly higher for FECF compared with MECF. Conclusions: MEP amplitude increased after nerve root decompression in both FECF and MECF, but the improvement rate was higher in FECF. These results suggest that FECF might be more minimally invasive than MECF in terms of neurological aspects.

Full-Endoscopic Lumbar Interbody Fusion for Treating Lumbar Disc Degeneration Involving Disc Height Loss: Technical Report.

Background and Objectives: Lumbar disc degeneration (LDD) is the main cause of lower back pain and leads to corresponding disc height loss. Although lumbar interbody fusion (LIF) is commonly used for treating LDD, several different treatment strategies are available. We performed a minimally invasive full-endoscopic LIF (FELIF) using a uniportal full-endoscopic system. Materials and Methods: FELIF was performed for 12 patients with LDD with disc-height loss using a 4.1 mm working channel endoscope and a newly developed slider for cage insertion. The mean age of the patients was 68.3 years; the patients presented with single vertebral level involvement. The Brandner's disc index was used for evaluating the postoperative increase in the disc height. Preoperative and postoperative leg pain was evaluated using the numerical rating scale (NRS) score. Results: The mean operation time for FELIF was 109.4 min. The mean duration of hospital stay after FELIF was 7.7 days. There were no operative and postoperative complications, even without drainage during the mean follow-up period of 6.2 months (range, 2-10 months). The Brandner's disc index improved statistically significant (p > 0.01). The mean preoperative and postoperative NRS scores were 6.5 and 1.2, respectively. Conclusions: FELIF using a 4.1 mm working channel endoscope can be used for treating LDD with disc height loss. Radiculopathy caused by foraminal stenosis was the most suitable operative indication for FELIF.

Comparative Study between Full-Endoscopic Discectomy and Microendoscopic Discectomy for the Treatment of Lumbar Disc Herniation.

Background and objectives: Lumbar disc herniation (LDH) is a common disease in the meridian of life. Although surgical discectomy is commonly used to treat LDH, there are several different strategies. We compared the outcomes of uniportal full-endoscopic discectomy (FED) with those of microendoscopic discectomy (MED) in treating LDH. Materials and Methods: FED was performed using a 4.1-mm working channel endoscope, and MED was performed using a 16-mm diameter tubular retractor and endoscope. Data of patients with LDH treated with FED (n = 39) or MED (n = 27) by the single surgeon were retrospectively reviewed. Patient background information and operative data were collected. Pre- and postoperative low back and leg pain were evaluated using the numerical rating scale (NRS) score. Pre- and postoperative disc height index (DHI) values were calculated from plain radiographs, and the disc height loss was evaluated using the ratio (DHI ratio); Results: The median (interquartile range (IQR) Q25-75) operation times for FED and MED were 42 (33-61) and 43 (33-50) minutes, respectively. The median (IQR Q25-75) pre- and postoperative NRS scores for low back pain were 5 (2-7) and 1 (0-4), respectively, for FED and 6 (3-8) and 1 (0-2), respectively, for MED. The median (IQR Q25-75) pre- and postoperative NRS scores for leg pain were 7 (5-8) and 0 (0-2), respectively, for FED and 6 (5-8) and 0 (0-2), respectively, for MED. These data were not different between the FED and MED groups. The median (IQR Q25-75) DHI ratios of FED and MED were 0.94 (0.89-1.03) and 0.90 (0.79-0.95), respectively. The DHI ratio was significantly higher (p < 0.05) in the FED group than in the MED group, and there was less blood loss; Conclusions: The pain-relieving effect of FED in treating LDH was almost identical to that of MED. However, FED was superior to MED in preventing disc height loss, which is one of the indicators of postoperative disc degeneration.

Epidemiology and psychological factors of whiplash associated disorders in Japanese population.

[Purpose] This study was designed to examine the epidemiological background of Whiplash-associated disorders in Japanese adults and to investigate the psychological factors associated with prolonged treatment for Whiplash-associated disorders. [Subjects and Methods] An online survey was completed by 127,956 participants, of whom 4,164 had been involved in a traffic collision. A random sample of the collision participants (n=1,698) were provided with a secondary questionnaire. From the 974 (57.4%) participants who returned the questionnaire, 183 cases (intractable neck pain treated over a period of 6 months) and 333 controls (minor neck pain treated within 3 months) were selected. Among the control group, the psychological factors associated with prolonged treatment for Whiplash-associated disorders were investigated. [Results] Among the 4,164 collision participants, 1,571 (37.7%) had experienced Whiplash-associated disorders. The prevalence in the general population was 1.2% (1.3% in male and 1.0% in female). Significant differences were observed between the cases and controls for all psychological factors, although both groups had similar distributions of age and gender. [Conclusion] Poor psychological factors were associated with prolonged treatment for whiplash-associated disorders in Japanese adults. These psychological factors should be considered during the treatment of whiplash-associated disorders.

Development and Achievement of Cervical Laminoplasty and Related Studies on Cervical Myelopathy.

Cervical laminoplasty (CL) is one of the surgical methods via the posterior approach for treating patients with multilevel affected cervical myelopathy (CM). The main purpose of CL is to decompress the cervical spinal cord by widening the narrowed spinal canal, combined with preserving the posterior anatomical structures to the degree possible and preserving the widened space stably. During the development and improvement of spine surgeries including CL, various studies on CM have progressed and useful achievements have been obtained: (1) posterior cervical spine fixation systems that can be used in combination with CL simultaneously have been developed; (2) various materials to stably maintain the enlarged spinal canal have been developed; (3) the main influential factors on the surgical results are the inner factors of the patients, such as the patient's age and the disease duration; (4) various surgical methods to preserve the function of the posterior cervical muscles have been tried to avoid postoperative kyphotic changes of the cervical spine; (5) postoperative complications, such as C5 palsy and axial pain, have been examined, and the countermeasures have been tried; (6) K-line on lateral X-ray films has been applied to evaluate the indication of CL in patients with CM due to ossification of the posterior longitudinal ligament (OPLL) preoperatively; and (7) the method and idea of CL have been adapted to surgeries at the thoracic and lumbar spine. However, some issues remain to be resolved, such as the deterioration of neurological findings, especially in patients with continuous or mixed-type OPLL, the postoperative kyphotic-directional alignment change of the cervical spine, C5 palsy, and axial pain.

A less invasive treatment by a full-endoscopic spine surgery for adjacent segment disease after lumbar interbody fusion.

BACKGROUND: Full-endoscopic spine surgery (FESS) is a suitable treatment for lumbar disc herniation (LDH) and foraminal stenosis. This study investigated the usefulness of FESS in treating adjacent segment disease (ASD) after lumbar interbody fusion (LIF). METHODS: Between September 2015 and March 2019, a total of 13 patients with symptomatic ASD after LIF underwent FESS. Discectomy and foraminoplasty using a 3.5-mm diameter high-speed drill were performed for treating LDH and foraminal stenosis. Preoperative and postoperative statuses were evaluated using Numerical Rating Scale (NRS) and the modified Japanese Orthopedic Association (mJOA) scores. RESULTS: The patients' mean age was 64.8 years; there were 10 male and 3 female patients. The mean operative time was 52.7 min. The mean pre- and postoperative NRS scores were 7.6 and 3.1, respectively. The mean pre- and postoperative mJOA scores were 10.5 and 16.1, respectively, and the mean recovery rate was 32.8%. Subsequent operative treatments were required in 3 patients for postoperative complication, insufficient decompression, and recurrence LDH. CONCLUSIONS: FESS is a safe and effective minimally invasive treatment for ASD after LIF and a potential alternative to extend the LIF to the adjacent vertebra or sacrum.

Full-endoscopic spine surgery for radiculopathy after osteoporotic vertebral compression fractures: a case report.

Full-endoscopic spine surgery (FESS) is a suitable treatment for lumbar disc herniation (LDH) and foraminal stenosis. Here, we describe the usefulness of FESS for treating radiculopathy after osteoporotic vertebral compression fractures (OVCFs). Between October 2018 and April 2019, three female patients (mean age, 81.7 years) with radiculopathy after OVCFs underwent FESS. Decompression of the corresponding nerve root was achieved using several FESS techniques, including foraminoplasty, discectomy, and removal of osteophyte or cement leakage. The mean operative time was 60.7 min. Preoperative and postoperative statuses were evaluated using numerical rating scale (NRS) scores. The mean pre- and postoperative NRS scores were 9 and 2.3, respectively. We observed no postoperative complications. Our results demonstrate that FESS is a safe and effective minimally invasive treatment for radiculopathy after OVCFs, with the potential to be an alternative to vertebroplasty, balloon kyphoplasty (BKP), or lumbar interbody fusion.

Postoperative C5 Palsy: Conjectured Causes and Effective Countermeasures.

Postoperative C5 palsy (C5 palsy) is defined as de novo or aggravating muscle weakness mainly at the C5 region with slight or no sensory disturbance after cervical spine surgery. The features of C5 palsy are as follows: 1) one-half of patients are accompanied by sensory disturbance or intolerable pain at the C5 region; 2) 92% of patients have hemilateral palsy; 3) almost all palsy occurs within a week after surgery; 4) the incidence is almost the same between the anterior and posterior approaches to the cervical spine; 5) the prognosis is relatively good even in patients with severe muscle weakness. Even now, the precise causes of C5 palsy have not yet been revealed. From the viewpoint of the kinds of nerve tissue involved, the uncertain causes of C5 palsy are divided into two theories: 1) the segmental spinal cord disorder theory and 2) the nerve root injury theory. In the former, the segmental spinal cord, particularly the anterior horn cells, is thought to be chemically damaged because of preoperative ischemia and/or the aggression of reactive oxygen during postoperative reperfusion. By contrast, in the latter, the anterior rootlet and/or nerve root are believed to be mechanically damaged because of compression force and/or distraction force. In this theory, the features of C5 palsy can be well explained from anatomical viewpoints. Additionally, various countermeasures have been proposed, such as the intermittent relaxation of the tension of the hooks to the multifidus muscles during surgery; prophylactic foraminotomy to decompress C5 nerve root; prevention of excessive posterior shift of the spinal cord, which may cause the tethering effect of the nerve root; and prevention of excessive postoperative lordotic alignment of the cervical spine. These countermeasures have been proved effective, and may support the nerve root injury theory as the main conjectured theory on the causes of C5 palsy.

Preoperative Design for the Posterolateral Approach in Full-Endoscopic Spine Surgery for the Treatment of L5/S1 Lumbar Disc Herniation.

OBJECTIVE: Full-endoscopic spine surgery (FESS) is a relatively less invasive treatment for lumbar disc herniation (LDH). This study investigated the optimal operative route of the posterolateral approach (PLA) of FESS for the treatment of L5/S1 LDH. METHODS: Between June 2016 and November 2018, a total of 21 patients with leg pain due to L5/S1 LDH underwent PLA of FESS. According to the partial removal of the superior articular process (SAP) of the L5/S1 facet joint (FJ), we categorized these patients into 2 groups. LDH type, anatomical configurations (FJ, sacral ala [SA], and iliac crest [IC]), the presence or absence of spondylolysis, operation time, and operative outcome were compared between these 2 groups. RESULTS: Although the anatomical configuration of the FJ was the most important factor for the necessity of SAP removal, the configuration of the SA and IC did not restrict endoscope insertion and subsequent LDH removal. Even in intracanal LDH, the removal of SAP was not absolutely required depending on the FJ configuration. Furthermore, the presence of spondylolysis was a factor associated with the unnecessity of SAP removal. CONCLUSION: Detailed radiological examination of the FJ configuration is an important preoperative investigation to determine the optimal operative route for PLA of FESS.

Side-shift exercise and hitch exercise.

We use side-shift exercise and hitch exercise for the treatment of idiopathic scoliosis. Outcomes of side-shift exercise used for the curves after skeletal maturity or used in combination with part-time brace wearing treatment are better than the natural history. Side-shift exercise and hitch exercise are useful treatment option for idiopathic scoliosis.

Surgical Treatment for Ossification of the Posterior Longitudinal Ligament (OPLL) at the Thoracic Spine: Usefulness of the Posterior Approach.

Various methods via anterior or posterior approach with or without spinal stabilization have been performed in accordance with the level and configuration of ossification of the posterior longitudinal ligament (OPLL) as the decompression surgery for thoracic myelopathy due to OPLL. Among them, anterior decompression at the middle thoracic level (T4/T5-T7/T8) is especially difficult to perform because of the special anatomical structures, where the spinal alignment is kyphotic and the thoracic cage containing circulatory-respiratory organs exist nearby. Of the anterior decompression procedures at this level, the posterior approach has various advantages compared to the anterior one. In the anterior approach, the procedure is complicated and the effect of decompression of the spinal cord can be obtained only by direct resection or anterior floating of the OPLL. However, complications such as spinal cord injury and dural tear are most likely to occur at that time. On the contrary, in the posterior approach, the procedure is simple, and various options to obtain decompression can be selected from, these are, laminectomy, laminoplasty, dekyphosis surgery, staged decompression surgery (Tsuzuki's method), circumferential decompression via posterior approach alone (Ohtsuka's method), and circumferential decompression via combined posterior and anterior approaches (Tomita's method). Among them, in laminectomy, laminoplasty, and dekyphosis surgery, anterior decompression can be obtained to some extent without performing direct procedure on the OPLL. In Ohtsuka's method, complete decompression can be obtained via posterior approach alone, although it is somewhat technically demanding. It is preferable to drop the shaved down and separated OPLL anteriorly instead of trying to remove it completely to avoid complications, especially in patients with severe adhesion between the dura mater and OPLL.

Multiple vertebral wedge osteotomy for adolescent idiopathic scoliosis.

19 idiopathic and 1 syringomyelia scoliosis patients (17 females and 3 males) underwent fusionless, multiple vertebral wedge osteotomy and with follow-up for an average of 8.9 years. The average age at surgery was 16.4 years. The average curve magnitude measured by Cobb was 64.0 degrees before surgery, 38.8 degrees after surgery, 43.7 degrees one year after surgery, 46.9 degrees two years after surgery and 48.2 degrees at the latest follow-up. The difference between the Cobb angle two years after surgery and latest follow-up was not significant. There were no major complications such as neurological problems.

Combined Video-Assisted Thoracic Surgery and Posterior Spinal Surgery for the Treatment of Dumbbell Tumor of the First Thoracic Nerve Root.

Although several cases of a dumbbell tumor of thoracic nerve roots have been reported, reports on the surgical procedures for a dumbbell tumor of the first thoracic (T1) nerve root are rare. Surgeons should be cautious, especially when performing a surgical procedure for a dumbbell tumor of the T1 nerve root because the tumor is anatomically located adjacent to important organs and because the T1 nerve root composes the lower trunk of the brachial plexus with the eighth cervical nerve root. We present cases with dumbbell tumors of the T1 nerve root that were treated with combined surgical treatment to remove the tumor. We first performed video-assisted thoracic surgery (VATS) to release the organs anteriorly and then performed posterior spinal surgery in the prone position. The combined VATS and posterior spinal surgery may become a standard surgical procedure for the treatment of dumbbell tumors of the T1 nerve root.

Enlarging vertebral body pneumatocysts in the cervical spine.

An intravertebral pneumatocyst is a relatively rare condition, and its natural course and etiology are unclear. We report a case of intravertebral pneumatocysts in the C5 vertebra that gradually enlarged during a 16-month period as documented by follow-up CT. In addition, direct communication was observed between the gas in the intervertebral disk and another pneumatocyst in the C6 vertebral body, which suggests that the gas in the pneumatocyst had an association with the gas in the degenerated intervertebral disk.

Image-guided resection for thoracic ossification of the ligamentum flavum.

OBJECT: The purpose of this study was to evaluate the advantages of using an image guidance system to aid in the resection of ossified of the ligamentum flavum (OLF) in the thoracic spine. The procedure and surgery-related outcome are discussed. METHODS: Ten patients with myelopathy underwent laminotomy with medial facetectomy and an image guidance system was used to remove the OLF. No neurological deterioration occurred, and postoperative computerized tomography scanning demonstrated successful decompression and good preservation of the lateral parts of the facet joints. CONCLUSIONS: The image guidance system allows accurate resection of the OLF while preserving as much as possible the facet joints and posterior elements of the thoracic spine.

Occipitalized os odontoideum: A case report.

We report on a 36-year-old man presenting with a sudden onset of motor weakness and numbness in the upper extremities following a fall from a truck bed. Radiological findings demonstrated an os odontoideum and osseous continuity between the occiput and an ossicle, termed an "occipitalized os odontoideum." The occipitalized ossicle and atlas moved as a functional unit from the body of the axis. He underwent atlantoasxial stabilization with an atlas lateral mass screw and axis pedicle screw. Eighteen months later, he remained free of symptoms and showed solid bone fusion. Atlantoaxial stabilization resulted in an excellent clinical outcome for this condition. Our report provides useful knowledge regarding treatment of extremely rare osseous anomalies in the craniovertebral junction.

Identification of risk factors for new-onset sciatica in Japanese workers: findings from the Japan epidemiological research of Occupation-related Back pain study.

STUDY DESIGN: Two-year, prospective cohort data collected for the Japan epidemiological research of Occupation-related Back pain study were used for the analysis. OBJECTIVE: To identify potential risk factors for the development of new-onset sciatica in initially symptom-free Japanese workers with no history of sciatica. SUMMARY OF BACKGROUND DATA: Although the associations between individual and occupational factors and cases of new-onset sciatica are established, the effect of psychosocial factors on the development of sciatica has still not been adequately clarified. METHODS: In total, 5310 participants responded to a self-administered baseline questionnaire (response rate: 86.5%). Furthermore, 3194 (60.2%) completed both 1- and 2-year follow-up questionnaires. The baseline questionnaire assessed individual characteristics, ergonomic work demands, and work-related psychosocial factors. The outcome of interest was new-onset sciatica with or without low back pain during the 2-year follow-up period. Incidence was calculated for participants who reported no low back pain in the preceding year and no history of lumbar radicular pain (sciatica) at baseline. Logistical regression assessed risk factors associated with new-onset sciatica. RESULTS: Of 765 eligible participants, 141 (18.4%) reported a new episode of sciatica during the 2-year follow-up. In crude analysis, significant associations were found between new-onset sciatica and age and obesity. In adjusted analysis, significant associations were found for obesity and mental workload in a qualitative aspect after controlling for age and sex. Consequently, in multivariate analysis with all the potential risk factors, age and obesity remained statistically significant (odds ratios: 1.59, 95% confidence interval: 1.01-2.52; odds ratios: 1.77, 95% confidence interval: 1.17-2.68, respectively). CONCLUSION: In previously asymptomatic Japanese workers, the risk of developing new-onset sciatica is mediated by individual factors. Our findings suggest that the management of obesity may prevent new-onset sciatica. LEVEL OF EVIDENCE: 3.

Milwaukee brace.

The Milwaukee brace had been a standard of nonsurgical treatment for scoliosis since 1954. Milwaukee brace 23-hours wearing protocol was most effective for the treatment of adolescent idiopathic scoliosis. However, Milwaukee brace 23-hours wearing showed an impact on psychosocial functioning of the patients. Moreover, even with thoraco-lumbo-sacral orthosis, 23-hours wearing protocol affects patients' psychosocial function. To maintain the effectiveness of the Milwaukee brace and at the same time to reduce physical and psychological burden of the patients, we adopted part-time wearing of Milwaukee brace. Our part-time wearing treatment was effective and did not affect the quality of life of the patients with idiopathic scoliosis.