Introduction: Although the prevalence and associated burden of low back pain (LBP) increase with age, research on LBP has primarily focused on young people and adults and little attention has been given to the elderly population. It has been reported that sarcopenia is common in elderly patients with chronic low back pain (CLBP); however, no evidence was observed that implies the associated mechanism of skeletal muscle mass reduction in chronic pain. Furthermore, no senescence-associated pain mechanism has been evaluated in the development of LBP. We investigated body compositional relevance, including skeletal muscle and fat volume, to global spinal alignment in elderly patients with CLBP.

Methods: Prospective data collection including laboratory analysis in hematological and biochemical test, vitamin D (25-OHD), body compositional measurement by whole-body dual-energy X-ray absorptiometry (DXA) to evaluate skeletal muscle and fat mass, global spinal sagittal alignment by plane radiograph and cross-sectional area of trunk muscle by magnetic resonance imaging (MRI) in the lumbar spine were obtained on 195 elderly patients with CLBP (averaged 79.1 years). Comparison was made by age- and sex-adjusted propensity score matching with the elderly control group.

Results: In CLBP, vitamin D was significantly low, red blood cell distribution width (RDW) was high, and lower skeletal muscle mass and higher fat volume with lower trunk muscle mass were observed. There were no significant differences between the two groups in lumbar disk and endplate degeneration; however, global spinal sagittal alignment showed CLBP with decreased lumbar lordosis, sagittal plane, and pelvic spinal imbalance.

Conclusions: RDW, which is an index of aging, was high among elderly patients with CLBP. In addition, it is considered that the presence of hypovitaminosis D in CLBP affects the pain threshold for geriatric nociception. Furthermore, age-related muscle mass reduction has potential for spinal and pelvic imbalance, leading to CLBP in the elderly. Elucidation of the mechanism of senescence may shed light on the novel procedure for CLBP.

Introduction: Postoperative C5 palsy (C5P) is a common complication after cervical spine decompression surgery. The etiology of C5P after anterior cervical decompression with spinal fusion (ASF) has not yet been fully described. Among anterior cervical decompressive procedures, both corpectomy and discectomy are important surgical methods, and both have their peculiar advantages and disadvantages. Corpectomy induces excessive dural expansion and shortening of the fixed segments. We thought that the environmental changes occurring after corpectomy might cause C5P, but it is unknown whether corpectomy affects the incidence of C5P. In the present study, we analyzed the effects of various combinations of decompression procedures on the incidence of C5P.

Methods: We retrospectively analyzed 839 patients who underwent ASF at a single institution. The surgical choice to use corpectomy, discectomy, or hybrid decompression (corpectomy combined with discectomy for an adjacent segment) was based on same treatment strategy depending on local compressive pathology and presenting clinical symptoms. For assessing the effects of various combinations of decompression procedures on C5P and the disc segments operated, we used an original "decompression combination score," which integrated both factors.

Results: C5P occurred in 57 (6.8%) patients. C5P did not occur immediately after surgery; the mean latency from surgery to its development was 4.6±5.6 days. A larger number of operated disc segments were significantly associated with C5P (p < 0.01). The incidences of C5P following various decompression procedures around the C4/5 segments were as follows: C4 and C5 corpectomy (10.1%) > C4 corpectomy (5.8%) > C5 corpectomy (4.8%) > C4/5 discectomy (4.1%). The decompression combination score was significantly higher in patients with C5P than in those without C5P (1.8 points vs. 1.5 points; p < 0.01). Higher scores were significantly associated with C5P (p < 0.01). Multivariate analysis revealed male sex [odds ratio (OR): 3.77, 95% confidence interval (CI): 1.72-8.26], higher decompression combination score (OR: 2.09, 95% CI: 1.28-3.44), and older age (OR: 1.08, 95% CI: 1.04-1.11) as significant risk factors. The estimated optimal cutoff values for predicting C5P using receiver-operating characteristic curve analysis were 1.5 points for the decompression combination score (area under the curve: 0.656) and 59 years for age (area under the curve: 0.675).

Conclusions: While performing ASF, C4/C5 corpectomy increased the incidence of C5P, whereas C4/C5 discectomy decreased the risk. The lower incidence of postoperative C5P after discectomy may be due to minimizing the tethering effect. As a preventive measure against C5P after ASF, corpectomy should be avoided, and discectomy is recommended as much as possible.

Introduction: Locomotive syndrome (LS) was proposed by the Japanese Orthopedic Association and refers to a scenario in which imminent future nursing care services will be required by elderly adults to manage the functional deterioration of their locomotive organs. It is a social imperative to determine the risk factors and treatment strategy for LS; however, the relationship between LS and adult spinal deformity (ASD) in those who are treated with spinal corrective surgery remains largely unknown. To establish the optimal surgical strategy for treating LS in patients with ASD, we sought to (1) determine the prevalence of LS in patients with ASD who were treated with spinal corrective surgery and (2) evaluate the improvement of LS after surgical spinal correction.

Methods: Forty-seven consecutive patients who had ASD and underwent spinal surgery for their disorder were included in this study. Locomotive dysfunction was evaluated using the 25-item Geriatric Locomotive Function Scale-25 (GLFS-25) questionnaire and physical performance tests, including the one-legged standing test, two-step test, stand-up test, handgrip strength test, and gait speed test, which were conducted preoperatively, 1 year after surgery, and 2 years after surgery.

Results: Among the patients with ASD who were treated surgically, 100% had LS preoperatively and 91% had grade 3 LS (LS3). Prevalence of LS3 significantly decreased 2 year after surgery by 55% compared with the preoperative rate. Among spinopelvic parameters, only the sagittal vertical axis (SVA) significantly correlated with the GLFS-25 values. The GLFS-25 items for the domains of pain, mobility, and domestic life improved overall postoperatively, whereas those in the self-care domain did not and the item for difficulty in putting on and taking off trousers and pants worsened.

Conclusions: Spinal corrective surgery significantly improved physical performance as well as the frequency and severity of LS in patients with ASD. However, some GLFS-25 items can worsen after surgery and require attention.

Introduction: In recent years, diseases of other departments have been discovered from images taken in each department, and their interpretation reports.

This leads to delay in treatment due to unread and omission of confirmation.

The problem is the delay in treatment due to unread and omission of confirmation. This study aimed to investigate other diseases in imaging tests that are suspected to be spinal disorders.

Methods: From June 2018 to May 2019, 5,149 imaging tests (MRI 3,453, CT 1,696) performed for spinal disorders were targeted. The presence or absence of diseases of other departments was confirmed by a radiologist's interpretation report, and the presence or absence of consultation with the relevant department and the disease were retrospectively investigated. Existing diseases were excluded and only new diseases were included.

Results: 319 cases of other diseases were found in the interpretation report, of which 103 cases were consulted with other departments and 32 cases were examined and treated.

Conclusions: It is often difficult to recognize diseases of other departments found other than the disease. In our department, a radiologist confirms the report of our department, extracts a report with a description of a disease of another department and creates a list and then distributes it to the doctor in charge and gets a confirmation. Next a nurse gives the final confirmation. We have confirmed the above triples. After introducing this system in our department, there are no unread reports. Measures are useful not only for orthopedists but also for multiple occupations.

Introduction: In this study, we report the surgical result of posterior stabilization using Transdiscal Screw for Diffuse idiopathic skeletal hyperostosis (TSD) for thoracolumbar spinal fracture accompanied by diffuse idiopathic skeletal hyperostosis (DISH) in comparison with the conventional posterior stabilization. TSD is the screw penetrating two vertebral endplates after passing through the pedicle of spine to achieve the better screw stability than conventional pedicle screw (PS).

Methods: This study was conducted retrospectively for patients aged over 70 years, who had the posterior stabilization for the thoracolumbar spinal fracture accompanied by DISH and could be followed up for a minimum of one year after surgery from 2003 to 2019 in our institution. Thirty eight subjects were eligible for this study and were divided into three groups (TSD group: n = 17, Percutaneous pedicle screw (PPS) group: n = 13, Open PS group: n = 8). The number of levels fused, number of screw used, surgical time, estimated blood loss, rate of screw loosening and fusion rate were investigated and compared within these three groups. Moreover, the maximum intraoperative screw insertion torque and screw size were also compared between 33 TSDs and 15 PPSs.

Results: The number of levels fused was 4.5, 5.3, and 7.1; the number of screws used was 8.1, 12.1, and 12.7; surgical time was 165.8 min, 151.6 min, and 219.7 min; and the estimated blood loss was 72.5 ml, 115.4 ml, and 453.7 ml for TSD group, PPS group, and Open PS group, respectively. There was a significant difference in the surgical time and estimated blood loss between the percutaneous method and open method (p < 0.05, p < 0.01). One screw loosening was found in the PPS group and Open PS, and bone union at the final follow-up was observed in all groups. Regarding the maximum intraoperative screw insertion torque, 175.3 N･m was for TSD and 141.8 N･m was for PPS. There was a significant difference between these two screws (p < 0.033). The longer screw could be inserted in TSD than PPS (p < 0.0001), but the screw diameter was same among the two screws.

Conclusions: These results suggest that TSD has a potential to be a stronger anchor than the pedicle screw in the case of thoracolumbar spinal fracture accompanied with DISH in the elderly patients.

Introduction: Reducing mechanical complications (MCs) after adult spinal deformity (ASD) surgery is challenging. This study aimed to identify predictive factors of MCs after ASD surgery.

Methods: Fifty-one patients (mean age, 71.2 years) who underwent thoracic-to-pelvis ASD surgery with ≥2 years follow-up were retrospectively reviewed. MCs included proximal junctional kyphosis (PJK), rod breakage (RB), and implant-related complications. Patient- and surgery-related factors, radiographic parameters (including spinopelvic), and postoperative global alignment and proportion (GAP) scores were compared between the non-MC and MC groups. A Cox proportional-hazards model was used to identify predictive factors of MCs.

Results: MCs occurred in 30 (59%) patients, and 31% of all patients required revision surgery. PJK was found in 33% (revision rate, 29%), and RB was found in 31% (revision rate, 69%). A higher rate of MCs was observed in three-column osteotomy (10% vs.37%, P = 0.048). The preoperative sagittal vertical axis (113 mm vs.144 mm, p = 0.044) and postoperative GAP score (4.4 vs.6.3, p = 0.026) were significantly higher in the MC group. The GAP score was an independent predictive factor associated with MCs (hazard ratio 1.357, 95% confidence interval 1.072-1.718, p = 0.011), and receiver operating characteristic curve analysis revealed that a GAP cutoff score of 8 points predicted revision surgery for MCs.

Conclusions: Among all patients, MCs occurred in 59%, and 31% required revision surgery. The GAP score was an independent predictive factor associated with MCs. Achieving proportional sagittal alignment may decrease the occurrence of MCs.

Introduction: Bone metastasis (BM) is more likely to occur in lung cancer (LC) and greatly affects patients' prognosis and quality of life. LC has been treated according to a histological classification that is based on genetic mutations. The epidermal growth factor receptor (EGFR) -tyrosine kinase inhibitor (TKI) and anaplastic lymphoma kinase (ALK) -TKI significantly prolong prognosis. However, few reports have examined BM in detail in terms of histological type. Therefore, we retrospectively investigated the period, site, and treatment of BM in LC and clarified the characteristics of BM progression on the basis of the histological type of LC.

Methods: A total of 87 patients with BM due to LC with pathological diagnosis between 2013 and 2017 at our institute were included and analyzed. Clinical charts and imaging studies were also reviewed.

Results: The patients included 24 cases of EGFR/ALK mutation positive adenocarcinoma (ADP), 38 cases of mutation negative adenocarcinoma (ADN), 13 cases of squamous cell carcinoma (SCC), and 12 cases of small cell LC (SCLC). TKI was administered to 95.8% of the patients with ADP. The period until BM diagnosis was shorter in patients with SCLC but longer in those with ADP (6.0 vs. 22.8 months). The incidence of BM at the time of diagnosis was lower in patients with SCC and higher in those with ADP and SCLC (BM score: 3.0 vs. 6.6 vs. 6.9, respectively; p < 0.05). BM score for patients with ADP was higher than that for patients with ADN (6.6 vs. 4.3; p = 0.053). The survival period after the first diagnosis of BM was shorter in patients with SCC but longer in those with ADP (3.6 vs. 13.2 month).

Conclusions: Patients with SCLC showed multiple BM in a relatively short time from LC diagnosis. Patients with ADP had a relatively long time until BM diagnosis and showed multiple lesions at that time. And the prognosis of life after BM diagnosis was relatively long. Histological prognosis of LC could be an indicator for orthopedic therapeutic interventions.

Introduction: Teriparatide has been used for the prevention of subsequent vertebral body fractures (SVBFs) following balloon kyphoplasty (BKP) and for the treatment of osteoporosis because it is efficacious in preventing SVBFs and is considered to be the most suitable alternative for this purpose. Romosozumab, an antisclerostin antibody, was made available in March 2019. A higher efficacy for the prevention of post-BKP SVBFs is expected from this drug as it effectively prevents vertebral body fractures and increases the bone density. In this study, we aimed to evaluate the efficacy of romosozumab in preventing SVBFs in comparison with other drugs, such as teriparatide, and obtain an index for selecting the optimal drug for patients after BKP.

Methods: A total of 320 patients who underwent initial BKP for vertebral compression fractures in our hospital were retrospectively analyzed, classified into four groups, and received romosozumab therapy (group R: 35 cases), daily teriparatide therapy (group D: 62 cases), weekly teriparatide therapy (group W: 122 cases), or alendronate therapy (control) (group C: 101 cases). Patients in these four groups were compared in terms of the 1-year incidence of SVBFs, rate of change in bone density, visual analog scale, and Oswestry Disability Index.

Results: The incidence of SVBFs was 8.6% in group R, 8.1% in group D, 6.6% in group W, and 13.9% in group C. In comparison with group C, the rate of change in lumbar vertebral bone density was significantly higher in group R at 4 months (+3.2%), 8 months (+5.9%), and 1 year (+10.8%), and in group D at 1 year (+3.3%).

Conclusions: Romosozumab increased vertebral bone density most prominently; however, the incidence of SVBFs in romosozumab therapy was similar to that of the two regimens of teriparatide therapy. The results suggest that the use of teriparatide or romosozumab mainly decreases the incidence of distant vertebral body fractures, leading to a decrease in the incidence of post-BKP SVBFs. Romosozumab is considered useful particularly for patients with severe osteoporosis, who require a rapid increase in the bone density.

Introduction: Spinal pseudarthrosis was defined in the revised guideline on osteoporotic vertebral fracture (OVF) in 2012 as the absence of visible signs of bone union 12 months following the injury. However, the clinical feature of pseudarthrosis remains unclear.

Methods: Among a total of 684 patients treated for OVF from January 2012 to February 2019 at our institution, 551 patients (mean age 81.9±7.4 years, male:female = 152:399) who could be followed up to 1 year were included in this study. The prevalence, risk factors, and its influence on the activities of daily living among patients with pseudarthrosis were investigated. The authors set pseudarthrosis as the objective variable, and total bone mineral density, skeletal muscle mass index, gender, age, history of osteoporosis treatment, presence of dementia, vertebral kyphosis angle, fracture type (presence of posterior wall injury), degree of independence in life before admission, history of steroid use, albumin level, renal function, presence of diabetes, and diffuse idiopathic skeletal hyperostosis as explanatory variables for multivariate analysis. The influence of pseudarthrosis on the walking ability and independence of daily living before and 1 year after OVF was studied.

Results: Fifty-four cases (9.8%) were diagnosed as having pseudarthrosis after 1 year (mean age 81.3±6.5 years, male:female = 18:36). Multivariate analysis showed that only presence of posterior wall injury showed statistical significance (OR = 2.059, p = 0.039). There was no significant difference between the pseudarthrosis group and the non-pseudarthrosis group in terms of walking ability and independence of daily living at 1 year.

Conclusions: The prevalence of pseudarthrosis following OVF was 9.8% and presence of posterior wall injury was its risk factor.

Introduction: Myelography and computed tomographic myelography (CTM) are widely used before spinal surgery. Findings that cannot be detected on magnetic resonance imaging (MRI) can sometimes be observed using myelography/CTM, which may result in changes in the surgery plans. In this study, we examined the usefulness of myelography/CTM in planning for lumbar surgery.

Methods: A total of 106 patients who underwent preoperative myelography were categorized into three groups: Group A, operation plans were changed or the decision to operate was taken after myelography/CTM; Group B, although new findings were observed on myelography/CTM, operation plans were not changed; and Group C, there were no new findings compared with MRI.

Results: Seven (6.6%) patients were classified into Group A: dynamic stenosis and increased decompression levels detected in three cases using myelography; lumbar spinal instability and presence of interbody fusions in three cases using myelography; and superior facet syndrome using CTM, leading to surgery in one case. Five cases (4.7%) were classified into Group B: ossification of the yellow ligament was detected on CTM in three cases; lumbar spondylosis, which was not identified on X-ray or MRI, was detected on CTM in one case; and a nerve root anomaly that could not be recognized on MRI was detected on CTM in one case. Ninety-four (88.7%) cases were classified into Group C.

Conclusions: Myelography/CTM aids in the recognition of the dynamic factors and understanding the pathophysiology of nerve root compression. It is a useful radiographic modality in planning for lumbar surgery.

Introduction: Spinal sagittal imbalance is reported to be associated with a decline in patients' quality of life; however, the cause of its progression has not been investigated. The purpose of this study was to clarify the characteristics of elderly patients with deteriorating spinal sagittal imbalance over a 2-year period.

Methods: A total of 321 participants (133 males and 188 females; mean age 72.9±4.9 years) from the Shiraniwa study were included in this analysis. Based on the SVA measured from whole spine radiographs, we classified the participants into the following three groups: SVA≤40 mm, 40 mm<SVA≤95 mm, and SVA>95 mm. Participants who showed disease progression from the first year to the third year were defined as the deteriorating spinal sagittal imbalance (DSI) group.

We compared the following items between DSI and non-DSI groups: the incidence of prevalent vertebral fractures, disc degeneration, and back muscle strength; locomotive syndrome (LS) stage 2; and sarcopenia. Using multiple logistic regression analysis, we investigated the predictors for DSI. Moreover, body composition measured using a bio-impedance analysis machine (BIA) was compared between the two groups.

Results: Overall, 45 (14.0%) participants were classified into the DSI group. The prevalence of LS stage 2 was significantly higher in the DSI group than in the non-DSI group (55.6% vs. 28.0%; p<0.01). LS stage 2 was an independent predictor of DSI with an adjusted odds ratio of 2.35 (95% CI: 1.08-5.12). Regarding the body composition measured by BIA, the ratio of trunk muscle to trunk weight percentage was significantly lower in the DSI group (male: 74.1%/78.2%, p=0.02; women: 63.7%/70.9%, p<0.01).

Conclusions: LS stage 2 was an independent predictor of deteriorating spinal sagittal imbalance over a 2-year period. Elderly patients with deteriorating spinal sagittal imbalance showed a significantly lower ratio of trunk muscle to trunk weight percentage.

Introduction: We report on the use of multivariate logistic regression analysis to examine the risk factors of pseudarthrosis after conservative treatment for lumbar spondylolysis.

Methods: A total of 196 lesions in 145 consecutive patients aged less than 18 years (mean age, 14.3 years; 114 males and 31 females) newly diagnosed with lumbar spondylolysis and treated with conservative therapy for 5 years from April 2014 were included in this study. At the initial examination, sex, age, level of lesion, main side stage, contralateral side stage, and presence of spina bifida occulta (SBO) in the lumbosacral vertebrae were investigated, and the relationship between each factor and bone union after conservative treatment was examined.

Results: In the multivariate analysis with level of lesion, main side stage, contralateral side stage, and SBO as explanatory variables, which were significant in the univariate analysis, main side progressive-stage lesion and progression of the contralateral lesions were found to be independent risk factors. Based on the results of the multivariate analysis, we defined main side progressive stage, contralateral very early stage, contralateral early stage, and contralateral progressive stage as low-risk factors and contralateral terminal stage as a high-risk factor. The proportion of lesions achieving bone union based on the number of risk factors was as follows: No risk factors, 99%; one low-risk factor, 86%; two low-risk factors, 66%; one high-risk factor, 50%; and one high- and one low-risk factor, 11%.

Conclusions: The independent risk factors for pseudarthrosis after conservative treatment for lumbar spondylolysis determined using multivariate analysis were main-side progressive-stage lesion and progression of the contralateral-side lesion. There was a difference in the bone union rate depending on the number of risk factors.

Introduction: Intradiscal gas imaging (IVP) is a sporadic finding and has been reported to be associated with low back pain and lumbar spine function. In this study, we examined the relationship between IVP and clinical findings.

Methods: We investigated the relationship between preoperative IVP detected on either X-p or CT and clinical findings obtained using VAS and JOABPEQ in 219 patients with lumbar spinal stenosis (including degenerative slips) who were operated at our hospital.

Results: IVP were detected in 33.3% of cases and 8.3% of discs on X-p, and in 71.2% of cases and 30.0% of discs on CT. The mean age of patients with IVP detected on X-p and CT was significantly higher and the mean VAS for low back pain tended to be higher than those in patients without IVP. In the comparison by age group, JOABPEQ for lumbar function of patients with IVP detected on X-p was significantly lower than that of patients without IVP in the age group of ≥80 years, and JOABPEQ for pain of patients with IVP detected on CT was also significantly lower than that of patients without IVP in the age group of ≥80 years. In VAS for low back pain, there was a significant increase in patients with IVP detected on CT compared with that in those without IVP in the age groups of 80+, 70-79, and 32-59 years.

Conclusions: Lumbar intradiscal gas increases with age, and patients with lumbar intradiscal gas are considered to have more severe low back pain and more severe lumbar dysfunction.

Introduction: Impacts of sagittal spinal alignment were examined on the clinical results of posterior decompression for lumbar spinal canal stenosis.

Methods: The subjects were 98 patients with lumbar spinal canal stenosis (61 men and 37 women, average age, 72 years) who presented with a chief complaint of neural symptom; the average follow-up period was 11 months. Subjects were compared by dividing into group N comprising 51 cases with SVA of ≤50 mm and group K comprising 47 cases with SVA of ≥51 mm.

Results: The average improvement ratio of Japanese Orthopaedic Association (JOA) score and visual analog scale (VAS) variation score of back and lower leg pain as well as lower leg numbness observed in group N and K were 57.7% and 54.3%, −16.8 and −28.3 mm, −19.2 and −42.4 mm, and −21.7 and −38.7 mm, respectively. The scores of group N and K obtained in the Japanese Orthopedic Association Back Pain Evaluation Questionnaire regarding disorders relating to pain, function disorder caused by back pain, locomotor function disorder, social life disorder, and psychological disorder were 16.3 and 32.5 points, 5.8 and 23.6 points, 22.7 and 25.0 points, 11.2 and 25.7 points, and 3.8 and 14.4 points, respectively. Lower leg pain VAS and function disorder caused by back pain was significantly improved in group K.

Conclusions: Even if sagittal alignment is poor, posterior decompression may obtain preferable performance as long as the chief complaint is neural symptom.

Introduction: We evaluated the postoperative outcomes of lower lumbar pyogenic spondylitis treated with minimally invasive spine stabilization (MISt).

Methods: This study included 11 patients (four males, seven females). The patients' average age was 68.1 years, and the average observation period was 19.4 months. The affected level was L4/5 in six patients and L5/S1 in five patients.

Results: The causative microorganism was detected in 54.5% of patients. Bone fusion was achieved in all 11 patients, and teriparatide was used in nine patients. Implant failure was confirmed in six patients; iliac screws were inserted in only three of these six patients, whereas iliac screws were inserted in all five patients without implant failure. The correction loss angle tended to be lower in patients with iliac screws (4.4°±4.1°) than in those without iliac screws (10.3°±2.9°) (p=0.05). Further comparison by affected level revealed significantly less correction loss at L5/S1 (8.5°±3.8°) than at L4/5 (3°±3.8°) (p<0.05).

Conclusions: In the case of the pyogenic spondylitis at lower lumbar spine, iliac screws should be inserted to enhance the fixation force of caudal anchor to reduce the correction loss and implant failure. Furthermore, teriparatide use should be considered in combination with iliac screws in cases of severe osteoporosis.