Background and Objective: Whiplash neck injury was described by Crowe in 1928. Whiplash-associated disorder (WAD) is defined as a cervical spinal injury following an acceleration-deceleration mechanism. It is a constellation of symptoms due to psychological factors and neural adaptations, with significant social costs.
Review Summary: There are multiple classification systems for WAD in the literature. The Quebec Classification is most reported and is predictive of the likelihood of progression to chronicity. The facet joint has been identified as a pain generator in 50% of cases. We outline the likely anatomical cause of WAD and summarize the protocol of medial branch block injections for diagnostic and therapeutic purposes, as well as the indications for and published results of facet joint ablation in WAD. We also highlight the development of ultrasound as an alternative to computed tomography or fluoroscopy for injection guidance.
Conclusions: WAD is a complex condition associated with sensory disturbance, pain, motor chronic pain, and psychological distress. The literature supports a single diagnostic medial branch block followed by a therapeutic facet joint ablation for chronic pain. WAD should be managed in a multidisciplinary fashion, with an early involvement of psychological specialists when required.
Adolescent idiopathic scoliosis (AIS) and Scheuermann's kyphosis (SK) are the most common types of spinal deformities in adolescents, and both have substantial ramifications on health-related quality of life (HRQoL) parameters. Various questionnaires have been developed to assess HRQoL in age-group populations with spinal deformity. Nevertheless, there remains a lack of consensus across the literature as to which instrument is the most suitable for evaluating the HRQoL of this cohort. Thus, this literature review was conducted to present disease-specific questionnaires for children and adolescents with AIS and SK to provide their psychometric characteristics (validity, reliability, and responsiveness) across different languages. A literature search was performed in the Medline (PubMed), Scopus, EMBASE, and Google Scholar databases. Studies that outlined the development and application of questionnaires evaluating HRQoL of children and adolescents with spinal deformity were included, and data on their validity and reliability in different translated languages were collected. A total of 10 disease-specific questionnaires were identified. Except for one questionnaire that was a proxy-reported measure, the other questionnaires were self-reported. We determined that selecting the proper questionnaire for clinical and research purposes requires careful consideration of various factors including the type of treatment intervention planned as well as various patient demographic factors. For children with early-onset scoliosis, the ideal questionnaire to evaluate their HRQoL is the Early-Onset Scoliosis Questionnaire-24. For adolescents with AIS and SK who are potential candidates for surgical intervention, the use of Scoliosis Research Society-22, Scoliosis Japanese-27, and Quality of Life Profile Spinal Deformity questionnaires is appropriate. For patients who are under nonsurgical treatment, the Brace Questionnaire and Italian Spine Youth Quality of Life questionnaires can be utilized. Nonetheless, when the specific intent of a study is to evaluate the self-image perception of patients, the use of drawing-based questionnaires may be the optimal choice.
The ossification of the spinal ligaments (OSL) is characterized by ectopic new bone formation in the spinal ligament. However, the etiology of OSL has not yet been fully elucidated. This review paper summarizes the contents of previous reviews, introduces recent advances in the study of OSL and discusses future perspectives. A review of the literature that investigated the biomarkers involved in OPLL was published in 2019. The review cited 11 reports in which a calcium phosphate metabolism marker, bone turnover markers, sclerostin, dickkopf-1, secreted frizzled-related protein-1, fibroblast growth factor-23, fibronectin, menatetrenone, leptin, pentosidine, and hypersensitive C-reactive protein were examined as markers. Data published in 2021 noted that non-coding RNAs might be useful biomarkers for OSL. In addition, triglycerides, uric acid, gene expression levels of interleukin-17 receptor C, chemokine (C-X-C motif) ligand 7 (CXCL7) in the serum reportedly are biomarkers of OSL. However, several issues have been raised in previous studies. Therefore, biomarkers have yet to be conclusively investigated. Research using biomarkers is very important in clarifying pathomechanisms. Results for studies using biomarkers might also be useful for the treatment of patients with OSL in the near future.
Introduction: Spine surgery is challenging in hemodialysis (HD) -dependent patients owing to their poor general condition. However, postoperative complications and the mortality and survival rates have not been specifically evaluated in a wide series. This study aimed to elucidate postoperative complications and the survival rate in cervical spine surgery in HD patients.
Methods: This study included 109 HD patients (70 men, 39 women) who had undergone cervical spine surgery between July 1996 and May 2018. Based on radiological diagnosis, we divided them into the destructive spondyloarthropathy (DSA) and non-DSA groups. We investigated the causes of hemodialysis, postoperative complications, postoperative inpatient mortality rate, and survival rate.
Results: The DSA and non-DSA groups included 100 surgeries in 89 patients and 21 surgeries in 20 patients, respectively. The mean age at surgery was 62.9 years for the DSA and 55.9 years for the non-DSA group (P=0.97). The DSA group had a shorter hemodialysis period at surgery compared with the non-DSA group (21.7 vs. 26.5 years, P<0.05). The two most common causes of HD in both groups were chronic glomerulonephritis (DSA, 45%; non-DSA, 57.1%) and diabetes (DSA, 11%; non-DSA, 14.5%). Postoperative complications were observed in 23% (23/100) and 19% (4/21) of surgeries in the DSA and non-DSA groups, respectively (P=0.782). The total in-hospital mortality rate was 2.5% (3/121). The 1-, 3-, 5-, and 10-year postoperative survival rates of all patients were 89.6%, 75.5%, 67.1%, and 44.7%, respectively. The survival rates did not depend on the group (DSA vs. non-DSA), pre- and postoperative Japanese Orthopedic Association score for cervical myelopathy, hemodialysis period, sex, and age (P>0.05). However, significantly low survival rates were observed in HD caused by diabetes compared with that by chronic glomerulonephritis (P<0.001) and other causes (P<0.001).
Conclusions: Cervical spine surgery in HD patients is associated with postoperative complications. The postoperative survival rate was found to be low if the cause of hemodialysis was diabetes.
Introduction: More spinal surgeries are being performed in patients taking low-dose aspirin for primary and secondary prevention of cardiovascular and cerebrovascular ischemic disease. However, there are no recommended guidelines for perioperative aspirin use in patients undergoing spinal surgery. This study evaluated the perioperative effect of continued low-dose aspirin on cervical laminoplasty.
Methods: This was a single-institute retrospective study of patients who underwent laminoplasty at the C2/3 to C7/T1 levels for cervical compression lesions. The comparison of 73 patients who continued to take aspirin at 100 mg/day during the perioperative period and 322 patients who took no antiplatelet or anticoagulant drugs examined their patient characteristics, perioperative parameters, and perioperative complications.
Results: A significantly higher proportion of patients with aspirin were men, and the mean age was significantly higher in patients with than without aspirin (P=0.011 and P<0.001, respectively). The preoperative hemoglobin level was significantly lower in patients with than without aspirin (P=0.033). The number of disk decompression levels, surgical time, intraoperative blood loss, and postoperative drainage volume were not significantly different between patients with and without aspirin. Reoperation for epidural hematoma formation was also not significantly different between patients with and without aspirin. Perioperative blood transfusions were performed in 1 of 73 patients with aspirin and 0 of 322 patients without aspirin, with no significant difference (P=0.185). No cardiovascular or cerebrovascular ischemic events occurred in either group.
Conclusions: Continuing low-dose aspirin therapy during a perioperative period for cervical laminoplasty did not increase perioperative bleeding or the risk of bleeding-related complications. Therefore, continuing low-dose aspirin may be acceptable for patients undergoing cervical laminoplasty to prevent increased risk of cardiovascular and cerebrovascular accidents due to aspirin withdrawal.
Introduction: Although lateral vertebral translation is associated with inducing curve progression and pain, no study has analyzed risk factors for lateral slip in patients with residual adolescent idiopathic scoliosis (AIS). This study aimed to investigate risk factors for lateral slip in patients with residual AIS.
Methods: We included 42 preoperative patients with residual AIS with a thoracolumbar/lumbar (TL/L) curve (3 male, 39 female; age 41.9±18.2 years, TL/L Cobb angle 55.5±10.0°). All patients were >20 years and had been diagnosed with AIS during their adolescence. Lateral slip was defined as more than a 6-mm slip on coronal CT images.
Results: Patients were divided into slip (n=22) and nonslip (n=20) groups. Significant differences were observed in age, TL/L Cobb angle, TL/L curve flexibility, lumbar lordosis, thoracolumbar kyphosis, apical vertebral rotation, apical vertebral translation, and L3 and L4 tilt between the groups. Multivariate analyses and receiver operating characteristic curves found that only older age was a significant risk factor for lateral slip (odds ratio: 1.214; 95% confidence interval: 1.047-1.407; P=0.010), with a cutoff value of 37 years old.
Conclusions: Older age, especially >37 years, is a risk factor for lateral slip in patients with residual AIS. These findings suggest that surgery for residual AIS should be considered before patients are in their mid-30s to avoid lateral translation.
Introduction: Chemonucleolysis with condoliase (chondroitin sulfate ABC endolyase) has been used to treat patients with lumbar disc herniation (LDH) in Japan since 2018. In this study, we retrospectively investigated clinical outcomes in patients who received an intradiscal condoliase injection for LDH and sought to identify significant predictors of good outcome.
Methods: Indications for treatment were as follows: (1) unilateral leg pain with or without back pain, (2) nerve root compression caused by LDH confirmed on magnetic resonance imaging (MRI), and (3) leg pain resistant to at least 1 month of conservative treatment, including medication, nerve root block, or physical therapy. Patients with motor weakness or a history of severe allergy were excluded, as were those with the foraminal or sequestrated type of LDH. The injection was defined as effective if the numeric rating scale score for leg pain improved by ≥50% at 6 months post-treatment.
Results: A total of 52 patients (mean age, 45.0 years) were enrolled and classified according to whether the injection was effective (E group, n=40, 76.9%) or less effective (L group, n=9, 17.3%). Three patients (5.8%) underwent herniotomy for residual pain within 6 months of the injection. There were no severe adverse events. Reduction of herniation was seen on MRI more often in the E group than in the L group. The effectiveness in patients with transligamentous LDH was similar to that in patients with subligamentous LDH. High-intensity signal change in the area of LDH on pretreatment T2-weighted MRI was a significant predictor of successful leg pain relief.
Conclusions: An intradiscal condoliase injection was a safe and effective treatment for painful radiculopathy caused by LDH. Leg pain was more likely to improve in patients with high-intensity signal change in the area of LDH before treatment.
Introduction: Exercise-induced low back pain (EILBP) is induced during anterior trunk tilting when walking or prolonged standing. In some elderly with chronic LBP, the pain is induced by EILBP. The paraspinal muscles play an important role in supporting the spine; therefore, a dysfunction of back muscles and kyphotic alignment are considered to be associated with EILBP. However, few reports are showing the relationship between EILBP and degenerative muscle changes. This study aimed to clarify the relationship between EILBP, degenerative changes of paraspinal muscles, and spinal alignment in an epidemiological study.
Methods: A total of 324 subjects were included in the analysis. The presence of EILBP was determined through a medical interview and physical examination. The subjects underwent lumbar spine magnetic resonance image (MRI) and X-ray. The fat infiltration rate (FIR) of the multifidus, erector spinae, and psoas major were analyzed using MRI. For lumbar sagittal balance, L1 axis S1 distance (LASD) was measured using X-ray images. Multivariate logistic regression analysis was used to analyze the association between the presence of EILBP and FIR or LASD.
Results: The prevalence of EILBP was 21% and it increased with age. The subjects with EILBP had statistically higher FIR of the multifidus, erector spinae, and psoas major than those without EILBP. There was a significant association between the presence of EILBP and higher FIR of the erector spinae at L1-2 and L5-S1 (p<0.05). However, there were no significant associations between EILBP and LASD.
Conclusions: According to the results in this study, EILBP is not rare and the FIR of the erector spinae is associated with the presence of EILBP.
Introduction: For early detection of surgical site infection (SSI) following spinal decompression surgery, we compared temporal changes in the values of laboratory markers that are not affected by operative parameters.
Methods: The study included 302 patients, which were divided into an SSI group (patients who developed deep SSI) and a non-SSI group for analysis. We reviewed data on C-reactive protein level, total white blood cell (WBC) count, and WBC differential percentage and count before spinal decompression, on postoperative day 1, and on postoperative day 4. We identified laboratory markers that are not affected by operative parameters (operating time, intraoperative blood loss, and number of operative segments). Laboratory markers with a significant difference observed between the peak or nadir value and the value in the subsequent survey day were considered as an indicator of SSI. We examined the utility of each indicator by calculating sensitivity and specificity. Furthermore, we investigated the utility of the combination of all five indicators (wherein the recognition of one marker was considered positive).
Results: Temporal changes in five laboratory markers were considered indicators of SSI. The changes from postoperative day 1 to postoperative day 4 were as follows: (1) increased WBC count (42% sensitivity, 88% specificity), (2) increased neutrophil percentage (25% sensitivity, 96% specificity), (3) increased neutrophil count (25% sensitivity, 94% specificity), (4) decreased lymphocyte percentage (25% sensitivity, 95% specificity), and (5) decreased lymphocyte count (25% sensitivity, 85% specificity). The combination of these five markers showed a 50% sensitivity, 81% specificity, and 0.65 AUC.
Conclusions: Five markers were found to be reliable indicators of SSI following spinal decompression surgery because they were not affected by operative parameters. The combination of all five indicators had moderate sensitivity and high specificity. Therefore, this may be reliable and useful for the early detection of SSI.
Introduction: A number of imaging technologies have been developed to reduce the risk of pedicle screw (PS) misplacement. For example, preoperative three-dimensional (3D) planning can reportedly enhance implant placement accuracy in some orthopedic surgeries. However, no study has investigated the effect of preoperative 3D planning on PS placement without intraoperative 3D navigation. Thus, in this study, we aim to examine the accuracy of PS placement and identify the risk factors for PS misplacement in thoracolumbar surgeries performed using preoperative 3D planning software with intraoperative fluoroscopic guidance in a retrospective study.
Methods: In total, 25 consecutive patients (197 PSs) underwent thoracic or lumbar spinal fusion surgeries using preoperative 3D planning with intraoperative fluoroscopic guidance. PS misplacement was graded based on the degree of perforation (Grade 0, no perforation; Grade 1, <2 mm; Grade 2, 2-4 mm; Grade 3, >4 mm) observed in postoperative computed tomography (CT). Deviations between planned and actual PSs were evaluated by matching preoperative and postoperative CT volume images for each vertebra.
Results: The overall PS misplacement rate was 6.6% (Grade 1: 4.0%, Grade 2: 1.5%, Grade 3: 1.0%). The median linear deviations of PS entry points between planned and actual locations were determined to be 3.3 mm and 3.3 mm for the horizontal and vertical axes, respectively. The median angular deviations of the PS axis were 6.2° and 4.5° for the transverse and sagittal planes, respectively. Multivariate analysis revealed that horizontal deviation of the PS entry point was the sole factor associated with Grade ≥1 PS misplacement (odds ratio=2.47, p<0.001).
Conclusions: Preoperative 3D planning software without intraoperative 3D navigation was able to achieve a relatively low PS misplacement ratio among the reported ratio of conventional techniques without navigation. Surgeons should carefully ensure that the entry point is consistent with preoperative planning, especially in the mediolateral direction to avoid misplacement in this method.
Introduction: This study investigated the efficacy and complications of preoperative embolization for spinal metastatic tumors, focusing on the etiology of post-embolization paralysis.
Methods: We retrospectively reviewed the data of 44 consecutive patients with spinal metastases treated between September 2012 and December 2020. Intraoperative blood loss and postoperative transfusion requirement were compared between the embolization (+) and (−) groups. Complications associated with embolization were reviewed.
Results: Overall, 30 patients (68%) underwent preoperative embolization. All the patients in both groups underwent palliative posterior decompression and fusion. The mean intraoperative blood loss in the overall population was 359 ml (range, minimum-2190 ml) and was 401 ml and 267 ml in the embolization (+) and embolization (−) groups, respectively. Four patients (9%) (2 patients from each group) required blood transfusion. There were no significant between-group differences in blood loss and blood transfusion requirements. All 7 patients with hypervascular tumors were in the embolization (+) group. Two patients experienced muscle weakness in the lower extremities on days 1 and 3 after embolization. There were metastases in T5 and T1-2, and magnetic resonance imaging after embolization showed slight exacerbation of spinal cord compression. The patients showed partial recovery after surgery.
Conclusions: With the predominance of hypervascular tumors in the embolization (+) group, preoperative embolization may positively affect intraoperative bleeding. Embolization of metastatic spinal tumors may pose a risk of paralysis. Although the cause of paralysis remains unclear, it might be due to the aggravation of spinal cord compression. Considering this risk of paralysis, we advocate performing surgery as soon as possible after embolization.
Introduction: Breast cancer is one of the most frequent primary tumors that cause spinal metastases. Metastasis consequences impair both the patient's overall prognosis and quality of life. We previously developed a porous hydroxyapatite collagen composite (HAp/Col) as an osteoconductive scaffold. HAp/Col is a commercially available artificial bone that is frequently utilized in spinal fusion. Because of its high absorbance capacity, HAp/Col is regarded as a good chemical carrier.
Methods: This study investigated the effect of local administration of paclitaxel combined with HAp/Col scaffold on breast cancer metastasis. High-performance liquid chromatography was used to assess the in vitro release of paclitaxel from HAp/Col. In an in vivo rat model, the inhibitory effects of paclitaxel-impregnated scaffolds on local osteogenesis was examined, and then the local suppression effects on metastatic cancer were investigated.
Results: In vitro testing revealed that roughly 30% of the paclitaxel was released within 96 hours. Paclitaxel-impregnated HAp/Col inhibited local osteogenesis for the first 8 weeks in a rat femur. However, at 12 weeks following surgery, this negative effect appeared to have subsided. In the metastatic model, all rats in the control group reached the humane endpoint 14 days after surgery. On the other hand, the average time to the endpoint in the paclitaxel group was 26.5 days, which was substantially longer than that in the control group. Long-term survivors treated with paclitaxel had no remaining tumor cells in the femoral bone, and osteogenesis was seen surrounding the HAp/Col.
Conclusions: Paclitaxel-impregnated HAp/Col reduced local tumor development and extended the time to the target endpoint in rats with metastases from breast cancer. This study shows that local implantation of paclitaxel-impregnated HAp/Col may be a viable therapeutic option for the management of breast cancer metastases.
Introduction: Wrong-site spine surgery is an incident that could result in possible severe complications. In this present spinal surgery, the accurate spinal level is confirmed via preoperative or intraoperative radiographic marking. However, the location of radiographic marking has been determined from the manual palpation on the landmarks of the body surface. As a result, severe spine deformity can make it hard to identify the spinal level by manual palpation, thus leading to misidentification of the spinal level.
Recently, the use of mixed reality in spine surgery is gradually increasing. In this study, we will demonstrate a head-mounted display (HMD) device that can project a hologram (3D image) of the patient's bone onto the actual patient's body to improve the accuracy of level identification for spine surgery.
Technical Note: 3D CT images are created preoperatively, and the bone's STL data (3D data) are generated with the workstation. The created STL data are downloaded to the augmented reality software Holoeyes, installed on the HMD. Through this device, surgeons can view the hologram (3D image) of a patient's bone overlaying on an actual patient's body.
We temporally estimated the spinous process level only by manual palpation without an HMD. Then, we estimated the spinous process level again after matching this hologram to a real bone with an HMD. The accuracy of the level identification with an HMD and without an HMD was examined by radiographic marking in order to evaluate the misidentification rate of the level. Without an HMD, the misidentification rate of the level was at 26.5%, while with it, the rate was reduced to 14.3%.
Conclusions: On preoperative marking, an HMD-projecting bone image onto a patient's body could allow us to estimate the spinal level more accurately. Identification of the spinal level using mixed reality is effective in preventing wrong-site spine surgery.