Prognostic value of psoas major muscle density in patients with breast cancer metastases to bone: a retrospective single-center cohort study.

OBJECTIVE: Although sarcopenia is associated with poor prognosis for cancer patients, the relationship between muscle quantity and quality, and prognosis of breast cancer patients with bone metastases is unclear. This study aims to evaluate the association of muscle parameters, muscle area and density, and overall survival (OS) from the diagnosis of bone metastases in breast cancer patients with bone metastases. METHODS: This study retrospectively investigated the prognostic value of muscle area and density in 90 women who were diagnosed with breast cancer with bone metastases between September 2005 and June 2018. We measured psoas major muscle and paravertebral muscle area and density on single axial computed tomography images at the L3 level and subgrouped the patients into higher or lower groups for each muscle measurement, using median values as cutoffs. We evaluated associations between OS and muscle parameters, using a Cox proportional hazards model adjusted by age and prognostic score for bone metastases (modified Katagiri score). RESULTS: Median OS among patients with lower psoas major muscle density (25 months) was significantly shorter than in the higher psoas major muscle density group (61 months; hazard ratio: 1.79, 95% confidence interval: 1.01-3.16, P = 0.045). However, muscle area and paravertebral muscle density were not associated with OS in this setting. CONCLUSION: Lower psoas major muscle density was a predictor of poor prognosis in patients with breast cancer metastases to bone. The association between psoas major muscle density and prognosis allows wider research into interventions that can prevent loss of muscle density.

Decreased muscle mass and strength affected spinal sagittal malalignment.

PURPOSE: Correction surgeries for spinal malalignment showed good clinical outcomes; however, there were concerns including increased invasiveness, complications, and impact on medico-economics. Ideally, an early intervention is needed. To better understand the patho-mechanism and natural course of spinal alignment, the effect of factors such as muscle mass and strength on spinal sagittal imbalance were determined in a multicenter cross-sectional study. METHODS: After excluding metal implant recipients, 1823 of 2551 patients (mean age: 69.2 ± 13.8 years; men 768, women 1055) were enrolled. Age, sex, past medical history (Charlson comorbidity index), body mass index (BMI), grip strength (GS), and trunk muscle mass (TM) were reviewed. Spinal sagittal imbalance was determined by the SRS-Schwab classification. Multiple comparison analysis among four groups (Normal, Mild, Moderate, Severe) and multinomial logistic regression analysis were performed. RESULTS: On multiple comparison analysis, with progressing spinal malalignment, age in both sexes tended to be higher; further, TM in women and GS in both sexes tended to be low. On multinomial logistic regression analysis, age and BMI were positively associated with spinal sagittal malalignment in Mild, Moderate, and Severe groups. TM in Moderate and Severe groups and GS in the Moderate group were negatively associated with spinal sagittal malalignment. CONCLUSION: Aging, obesity, low TM, and low GS are potential risk factors for spinal sagittal malalignment. Especially, low TM and low GS are potentially associated with more progressed spinal sagittal malalignment. Thus, early intervention for muscles, such as exercise therapy, is needed, while the spinal sagittal alignment is normal or mildly affected.

Low paravertebral muscle mass in patients with bone metastases from lung cancer is associated with poor prognosis.

PURPOSE: Low skeletal muscle mass has been associated with poor prognosis in patients with advanced lung cancer. However, little is known about the relationship between skeletal muscle mass and overall survival in patients with bone metastases from lung cancer. The objective of the present study was to evaluate the prognostic value of low trunk muscle mass in predicting overall survival in these patients. METHODS: The data from 198 patients who were diagnosed with bone metastases from lung cancer from April 2009 to May 2017 were retrospectively reviewed. The areas of the psoas and paravertebral muscles were measured at the level of the third lumbar vertebra on computed tomography scans taken at the time nearest to the diagnosis of bone metastasis. Muscle area was evaluated for male and female cohorts separately using different cutoff points. Cox proportional hazards analysis was performed to evaluate the factors independently associated with overall survival. RESULTS: The overall survival of patients in the lowest quartile for psoas muscle area or paravertebral muscle area was significantly shorter than that of patients above the 25th percentile for muscle area (p < 0.001). Multivariate analyses showed that paravertebral muscle mass (hazard ratio, 1.73; 95% confidence interval, 1.17-2.56; p = 0.006), epidermal growth factor receptor-targeted therapy, and performance status were independent prognostic factors. CONCLUSIONS: Low paravertebral muscle mass was associated with shorter survival, independently of known prognostic factors.

Prognostic value of paravertebral muscle density in patients with spinal metastases from gastrointestinal cancer.

PURPOSE: Morphometric analyses have shown that trunk muscle mass and density are associated with mortality in cancer patients. Because of the low incidence of spinal metastasis from gastrointestinal cancer and the limited life expectancy of these patients, few studies have been reported in this population. We evaluated the prognostic value of trunk muscle area and density in predicting overall survival. METHODS: The data from 78 patients with spinal metastases from gastrointestinal cancer, collected from February 2009 to July 2016, were evaluated. Psoas muscle and paravertebral muscle area and density were measured at the L3 level on CT scans taken at the time nearest to the diagnosis of spinal metastasis. Cox proportional hazards analysis was performed to evaluate the factors independently associated with overall survival. RESULTS: The mean patient age was 68.3 years (range, 42-88 years). The overall median survival time was 4.8 months: 2.2 months in the extremely rapid growth group (stomach, biliary tract, and pancreas) and 7.6 months in the rapid growth group (esophagus, liver, and colorectum). Multivariate analyses showed that lower paravertebral muscle density (HR 2.23 [95% CI 1.24-3.99], p = 0.007), extremely rapid growth group, presence of abnormal laboratory data, poor performance status, and chemotherapy after spinal metastasis were independent prognostic factors. CONCLUSIONS: Median overall survival was poor among patients with spinal metastases from gastrointestinal carcinoma, especially among those with gastric, biliary tract, or pancreatic cancer. Lower paravertebral muscle density was an independent poor prognostic factor in patients with spinal metastases from gastrointestinal cancer.

ISSLS PRIZE IN CLINICAL SCIENCE 2019: clinical importance of trunk muscle mass for low back pain, spinal balance, and quality of life-a multicenter cross-sectional study.

STUDY DESIGN: A multicenter cross-sectional study. OBJECTIVES: To clarify the relationship of trunk muscle mass with low back pain, spinal sagittal balance, and quality of life. Few reports have investigated the relationship of trunk muscle mass with lumbar spine function and spinal balance, and the clinical significance of trunk muscle mass remains unclear. METHODS: Patients attending spinal outpatient clinics at 10 different medical institutions were enrolled in this study. Patient demographics, trunk muscle mass and appendicular skeletal muscle mass (ASM) measured by bioelectrical impedance analysis (BIA), body mass index (BMI), Charlson Comorbidity Index (CCI), the Oswestry Disability Index (ODI), visual analog scale (VAS) for low back pain, sagittal vertical axis (SVA), and EuroQol 5 Dimension (EQ5D) score were investigated. Multivariate nonlinear regression analysis was used to investigate the association of trunk muscle mass with the ODI, VAS score, SVA, and EQ5D score. RESULTS: Of 2551 eligible patients, 1738 (mean age 70.2 ± 11.0 years; 781 men and 957 women) were enrolled. Trunk muscle mass was significantly correlated with the ODI, VAS score, SVA, and EQ5D score (P < 0.001) when adjusted for age, sex, BMI, ASM, CCI, and history of lumbar surgery. Patient deterioration was associated with a decrease in trunk muscle mass, and the deterioration accelerated from approximately 23 kg. CONCLUSIONS: Trunk muscle mass was significantly associated with the ODI, VAS score, SVA, and EQ5D score. Trunk muscle mass may assume an important role to elucidate and treat lumbar spinal dysfunction and spinal imbalance. These slides can be retrieved under Electronic Supplementary Material.

Differences in short-term clinical and radiological outcomes depending on timing of balloon kyphoplasty for painful osteoporotic vertebral fracture.

BACKGROUND: Balloon kyphoplasty or vertebroplasty is widely performed as a surgical intervention for osteoporotic vertebral fracture (OVF) and the effects have been investigated in many previous studies. However, the influence of the timing of the procedure on patient outcomes has not been studied formally. The purpose of this study was to investigate differences in the surgical outcomes of OVFs according to the timing of balloon kyphoplasty. METHODS: This was a multicenter cohort study. Participants comprised 72 consecutive patients who underwent balloon kyphoplasty between January 2012 and January 2016. Patients were analyzed in two groups according to the timing of kyphoplasty after onset (Early group: ≤2 months; Late group: >2 months). Follow-up continued for more than 6 months. RESULTS: A total of 72 patients were effectively analyzed. Of these, 27 (38%) patients underwent kyphoplasty within 2 months after symptom onset. The Late group showed greater angular motion of fractured vertebrae (p = 0.005) and compression of anterior vertebral height (p = 0.001) before surgery. Final outcomes adjusted for age and preoperative outcome showed lower visual analog scale (VAS) scores for low back pain in the Early group than in the Late group (19.9 vs. 30.4, p = 0.049). Final relative anterior vertebral height and kyphotic angle were more preserved in the Early group than in the Late group (p = 0.002 and p = 0.020, respectively), although absolute differences were not significant. CONCLUSIONS: Vertebral height and kyphotic angle before and after balloon kyphoplasty were greater in patients who underwent kyphoplasty within 2 months after onset, and the VAS score for low back pain at final follow-up was better. Our results support kyphoplasty within 2 months.

Overall survival and prognostic factors in patients with spinal metastases from lung cancer treated with and without epidermal growth factor receptor tyrosine kinase inhibitors.

BACKGROUND: Evaluation of the prognosis in patients with spinal metastases is important in decision making regarding surgical treatment. The purpose of this study was to investigate overall survival in patients with spinal metastases from lung cancer by histological subtype, and to investigate prognostic factors in patients treated with and without epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). METHODS: The data from 135 patients diagnosed with spinal metastases from lung cancer were retrospectively evaluated. The 88 patients with adenocarcinoma were divided into two groups according to whether the lung cancer was treated with or without EGFR-TKIs-the EGFR-TKI group (n = 43) and the non-EGFR-TKI group (n = 45). RESULTS: The overall median survival time was 11.3 months for those with adenocarcinoma, 5.3 months for squamous cell carcinoma, and 3.9 months for small cell carcinoma. Overall survival in the EGFR-TKI group (median 21.4 months) was significantly longer than in the non-EGFR-TKI group (median 6.1 months). In univariate analysis, poor performance status was a poor prognostic factor in the non-EGFR-TKI group. However, performance status and other variables were not significant prognostic factors in the EGFR-TKI group. CONCLUSIONS: Median overall survival was longer in patients with spinal metastases from lung cancer treated with EGFR-TKIs compared with those treated without EGFR-TKIs. Poor performance status or other prognostic factors were not associated with poor overall survival in the group treated with EGFR-TKIs.

The relationship between cervical and lumbar spine lesions in rheumatoid arthritis with a focus on endplate erosion.

STUDY DESIGN: A cross-sectional imaging study. OBJECTIVE: To investigate the relationship between cervical and lumbar spine lesions in patients with rheumatoid arthritis (RA), and to analyze associated factors in those with concurrent cervical and lumbar endplate erosion (EE). SUMMARY OF BACKGROUND DATA: Both the lumbar and cervical spines are often involved in RA, but little is known about the relationship between cervical and lumbar lesions. EE is often found in the spine of RA patients, but its prevalence and associated factors have not been well studied. METHODS: We enrolled 201 RA patients in this study. Cervical lesions (horizontal and vertical atlantoaxial dislocation, subaxial subluxation) and lumbar lesions (vertebral fracture, scoliosis, spondylolisthesis) were evaluated on plain radiographs. EE was evaluated on sagittal T1-weighted magnetic resonance images, and graded into 4 categories. The prevalence of each lesion was calculated, and correlations between general cervical and lumbar lesions and between cervical and lumbar EE were analyzed. To assess the clinical condition of RA, we evaluated disease duration, Steinbrocker stage, modified Stanford Health Assessment Questionnaire results, and Disease Activity Score for 28 joints with the erythrocyte sedimentation rate. Factors associated with concurrent lumbar and cervical EE were analyzed using multiple logistic regression analysis. RESULTS: Cervical lesions were found in 42.3% of patients and lumbar lesions in 56.2%. There was no significant correlation between the presence of cervical and the presence of lumbar lesions, but patients with cervical subaxial subluxation were significantly more likely to have lumbar spondylolisthesis. Cervical EE (≥1 points) was found in 61.2% of patients and lumbar EE in 39.3%. Total cervical EE score was significantly correlated with lumbar EE score. Moderate/high disease activity, Steinbrocker stage IV, and severe cervical or lumbar disk degeneration were associated with concurrent cervical and lumbar EE. CONCLUSIONS: Some cervical lesions are significantly associated with lumbar spinal lesions. Concurrent cervical and lumbar EE are related to RA disease activity and peripheral joint deterioration, suggesting that RA activity may play an important role in total spinal involvement.

Risk Factors for Residual Back Pain After Balloon Kyphoplasty for Osteoporotic Vertebral Fracture.

Background: Balloon kyphoplasty (BKP) is a method for the management of osteoporotic vertebral body fracture (OVF). However, improvement in back pain (BP) is poor in some patients, also previous reports have not elucidated the exact incidence and risk factors for residual BP after BKP. We clarified the characteristics of residual BP after BKP in patients with OVF. Hypothesis: In this study, we hypothesize that some risk factors may exist for residual BP 2 years after the treatment of OVF with BKP. Patients and Methods: A multicenter cohort study was performed where patients who received BKP within 2 months of OVF injury were followed-up for 2 years. BP at 6 months after surgery and final observation was evaluated by Visual Analog Scale (VAS) score. Patients with a score of 40 mm or more were allocated to the residual BP group, and comparisons between the residual back pain group and the improved group were made for bone density, kyphosis, mobility of the fractured vertebral body, total spinal column alignment, and fracture type (fracture of the posterior element, pedicle fracture, presence or absence of posterior wall damage, etc.). Also, Short Form 36 (SF-36) for physical component summary (PCS) and mental component summary (MCS) at the final follow-up was evaluated in each radiological finding. Results: Of 116 cases, 79 (68%) were followed-up for 2 years. Two years after the BKP, 26 patients (33%) experienced residual BP. Neither age nor sex differed between the groups. In addition, there was no difference in bone mineral density, BKP intervention period (period from onset to BKP), and osteoporosis drug use. However, the preoperative height ratio of the vertebral body was significantly worse in the residual BP group (39.8% vs. 52.1%; p = 0.007). Two years after the operation, the vertebral body wedge angle was significantly greater in the residual BP group (15.7° vs. 11.9°; p = 0.042). In the multiple logistic regression model with a preoperative vertebral body height ratio of 50% or less [calculated by receiver operating characteristic (ROC) curve], the adjusted odds ratio for residual BP was 6.58 (95% confidence interval 1.64-26.30; p = 0.007); similarly, patients with vertebral body height ratio less than 50% had a lower score of SF-36 PCS 24.6 vs. 32.2 p = 0.08. Conclusion: The incidence of residual BP 2 years after BKP was 33% in the current study. The risk factor for residual BP after BKP was a preoperative vertebral body height ratio of 50% or less, which should be attentively assessed for the selection of a proper treatment scheme and to provide adequate stabilization. Level of Evidence: III.

Association between Opioid Requirement and Overall Survival in Patients with Spinal Metastases.

Introduction: Clinical evidence shows that opioid administration in cancer patients is associated with shorter survival. This study explored the impact of opioid requirement on overall survival of patients with spinal metastases. We also evaluated the association between opioid requirement and tumor-related spinal instability. Methods: We retrospectively identified 428 patients who had been diagnosed with spinal metastases from February 2009 to May 2017. Those with an opioid prescription during the first 1 month after the diagnosis were included in this study. Patients given opioids were divided into two groups: the opioid requirement group [≥5 mg oral morphine equivalent (OME)/day] and the nonopioid group (<5 mg OME/day). Spinal instability due to metastases was evaluated using the Spinal Instability Neoplastic Score (SINS). Cox proportional hazards analysis was performed to evaluate the relationship between opioid use and overall survival. Results: The most frequent primary cancer site was the lung, in 159 patients (37%), followed by the breast in 75 (18%) and the prostate in 46 (11%). Multivariate analyses showed that patients who required ≥5 mg OME/day were approximately twofold more likely to die after a spinal metastases diagnosis than those who required <5 mg OME/day (hazard ratio 2.13; 95% confidence interval 1.69-2.67; p<0.001). The SINS was significantly higher in the opioid requirement group than those in the nonopioid group (p<0.001). Conclusions: For patients with spinal metastases, opioid requirement was associated with shorter survival, independently of known prognostic factors. The patients were also more likely to have tumor-related spinal instability than those in the nonopioid group.

Efficacy of interspinous process lumbar fusion with recombinant human bone morphogenetic protein-2 delivered with a synthetic polymer and ß-tricalcium phosphate in a rabbit model.

INTRODUCTION: As a powerful bone-inducing cytokine, rhBMP-2 has been used as a bone graft substitute in combination with animal-derived collagen to achieve interbody or posterolateral spinal fusion. Successful interspinous process fusion using rhBMP-2 in combination with synthetic carrier materials would offer a safe, minimally invasive spinal fusion option for the treatment of spinal disorders. The aims of the present study were to achieve interspinous process fusion by implanting rhBMP-2-retaining degradable material instead of bone grafting and to evaluate efficacy for vertebral stabilization. MATERIALS AND METHODS: A polymer gel (200 mg), ß-tricalcium phosphate powder (400 mg), and rhBMP-2 (0, 30, 60 or 120 µg) were mixed to generate a plastic implant, which was then placed during surgery to bridge the L5-6 interspinous processes of 58 rabbits. Control animals received implants either without rhBMP-2 or with autogenous bone chips from the iliac crest. L5-6 vertebrae were recovered 8 weeks postoperatively. Interspinous process fusion was evaluated by radiography, biomechanical bending test, intradiscal pressure (IDP) measurement, and histology. RESULTS: In bending tests, strength of fusion was significantly greater in BMP60 and BMP120 groups than in sham, BMP0, BMP30 or autogenous bone groups. IDP at L5-6 was significantly reduced in BMP60 and BMP120 groups compared to sham, BMP0, BMP30, and autograft groups. Histologically, coronal sections of the fusion mass showed a bone mass bridging both spinous processes. CONCLUSION: Solid interspinous process fusion was achieved in rabbit models by 8 weeks after implanting the biodegradable bone-inducing material. These results suggest a potential new less-invasive option without bone grafting for the treatment of lumbar disorders.

Association between Age and Trunk Muscle Area and Density in Patients with Spinal Metastases.

STUDY DESIGN: A retrospective study. PURPOSE: This study aimed to evaluate the relationship between age and trunk muscle composition and between trunk muscle composition and overall survival in patients with spinal metastasis. OVERVIEW OF LITERATURE: A low skeletal muscle mass is associated with a poor overall survival in patients with cancer. However, no previous studies have evaluated the relative effects of age and disease on muscle mass and muscle quality in patients with advanced cancer. METHODS: This study included 539 patients diagnosed with spinal metastasis from February 2009 to July 2018. The patients were categorized into four groups based on age: <59, 60-69, 70-79, and ≥80 years. Differences in trunk muscle composition among age groups and among groups were classified on the basis of survival (< or >3 months after spinal metastasis diagnosis) were evaluated. RESULTS: In total, 515 patients (273 men, 242 women; mean age, 67.8 years) with complete medical records were included in the analysis. No significant differences were observed in the area of the psoas and paravertebral muscles among age groups in either sex. A significant trend toward a low muscle density with the increase in age was found for both sexes. Patients who survived less than 3 months had significantly smaller trunk muscle area than those who survived for more than 3 months in both sexes. CONCLUSIONS: The results suggest that the reduction in muscle density is associated with advanced age, whereas a decreased muscle area is associated with pathology. Additionally, a small trunk muscle area was associated with a short overall survival. Further studies are needed to elucidate the underlying mechanisms of age- versus cancer-related changes in the muscle area and their influence on overall survival.

Presence of sarcopenia does not affect the clinical results of balloon kyphoplasty for acute osteoporotic vertebral fracture.

Sarcopenia has been associated with poor clinical outcomes in several diseases. Herein, the clinical results of balloon kyphoplasty (BKP) for acute osteoporotic vertebral fracture (OVF) treatment were assessed and compared between sarcopenia and non-sarcopenia patients. Sixty patients who underwent BKP for treatment of acute OVF with poor prognostic factors between April 2016 and September 2017 and were assessed for sarcopenia were enrolled. Clinical results (back pain on visual analogue scale [VAS]; short-form [SF] 36; vertebral deformity; activities of daily living levels; and incidence of adjacent vertebral fractures) were compared between the two groups at 6 months post-BKP. Data analysis revealed that back pain on VAS, SF-36 scores, and vertebral deformity improved from baseline to 6 months after BKP. Thirty-nine patients (65.0%) were diagnosed with sarcopenia and demonstrated a lower body mass index (21.2 vs. 23.3 kg/m2, p = 0.02), skeletal muscle mass index (5.32 vs. 6.55 kg/m2, p < 0.01), hand-grip strength (14.7 vs. 19.2 kg, p = 0.01), and bone mineral density of the femoral neck (0.57 vs. 0.76 g/cm2, p < 0.01) than those of patients without sarcopenia. However, no significant differences were observed in the clinical results between these groups. Therefore, BKP's clinical results for the treatment of acute OVF are not associated with sarcopenia.

Gender-specific analysis for the association between trunk muscle mass and spinal pathologies.

We investigated the relationship between trunk muscle mass and spinal pathologies by gender. This multicenter cross-sectional study included patients aged ≥ 30 years who visited a spinal outpatient clinic. Trunk and appendicular muscle mass were measured using bioelectrical impedance analysis. The Oswestry Disability Index (ODI), visual analog scale (VAS) score for low back pain, sagittal vertical axis (SVA), and EuroQol 5 Dimension (EQ5D) score were investigated to evaluate spinal pathology. The association between trunk muscle mass and these parameters was analyzed by gender using a non-linear regression model adjusted for patients' demographics. We investigated the association between age and trunk muscle mass. We included 781 men and 957 women. Trunk muscle mass differed significantly between men and women, although it decreased with age after age 70 in both genders. Lower trunk muscle mass was significantly associated with ODI, SVA, and EQ5D score deterioration in both genders; its association with VAS was significant only in men. Most parameters deteriorated when trunk muscle mass was < 26 kg in men and < 19 kg in women. Lower trunk muscle mass was associated with lumbar disability, spinal imbalance, and poor quality of life in both genders, with significant difference in muscle mass.

Bow hunter's syndrome after cervical laminoplasty in a patient with rheumatoid arthritis with bony ankylosis in the cervical spine: a case report.

Bow hunter's syndrome, or rotational vertebral artery (VA) occlusion, refers to vertebrobasilar insufficiency due to mechanical occlusion of the VA. We present a case of surgical treatment for bow hunter's syndrome that occurred after cervical laminoplasty in a patient with rheumatoid arthritis with bony ankylosis of the facet joints. A 59-year-old female with rheumatoid arthritis experienced sudden incomplete left hemiplegia. Fifteen months earlier, the patient had undergone cervical decompression surgery between C3 and C7. MRI of the head showed cerebral infarction in the right VA area, while vertebral angiography with the head rotated to the right revealed that the right VA was occluded at the level of C3-C4. The patient was successfully treated via posterior cervical fusion from C2 to C7. Patients with rheumatoid arthritis have a potential risk of cervical bony ankyloses. Cervical laminoplasty for patients with cervical bony ankyloses can induce rotational VA occlusion due to spinal rotational instability.

Successful spinal fusion by E. coli-derived BMP-2-adsorbed porous beta-TCP granules: a pilot study.

Bone morphogenetic proteins (BMPs) were originally identified as osteoinductive proteins. With cloning of BMP genes, studies of BMPs and their clinical application have advanced. However, with increasing clinical applications, drug delivery systems and production costs have become more important issues. To address these issues, we asked whether E. coli-derived rhBMP-2 (E-BMP-2)-adsorbed porous beta-TCP granules could achieve posterolateral lumbar fusion in a rabbit model similar to autogenous bone grafts. Lumbar spinal fusion masses were evaluated by 3-D computed tomography, mechanical testing, and histological analyses 8 weeks after surgery. By these measures E-BMP-2-adsorbed beta-TCP granules achieved lumbar spinal fusion in dose-dependent fashion in a rabbit model as well as autogenous bone graft. Our preliminary findings suggest E-BMP-2-adsorbed porous beta-TCP could be a novel, effective alternative to autogenous bone grafting for generating new bone and promoting regenerative repair of bone, and potentially utilizable in the clinical setting for treating spinal disorders.

Prognostic value of low psoas muscle mass in patients with cervical spine metastasis.

Morphometric analyses have shown that the psoas muscle mass is associated with mortality in cancer patients. Because of the low incidence of cervical spine metastasis, few studies have been reported in this population. The present study aimed to identify the prognostic value of a psoas muscle mass in predicting overall survival. We also evaluated factors associated with surgical intervention for cervical spine metastases. We retrospectively evaluated 97 patients (mean age 65.2 years) diagnosed with cervical spine metastases between February 2009 and July 2016. The psoas muscle area was measured at the L3 level on computed tomography at the time nearest the diagnosis of cervical spine metastasis. Cox proportional hazards analyses were performed to evaluate the relation between overall survival and the psoas muscle's composition. The mean overall survival for patients who underwent surgery was not significantly different from that for those without surgery. Multivariate analyses showed that the lowest percentage quartile (0%-25%) of the psoas muscle mass was associated with poor overall survival after adjusting for age and the prognostic predictive value (hazard ratio 1.93, 95% confidence interval 1.12-3.32; p = 0.017). Spinal cord compression, spinal instability, palsy, and the poor prognostic predictive value were factors associated with surgical intervention. In conclusion, a psoas muscle mass in the lowest quartile was independently associated with shorter survival among patients with cervical spine metastases. Although the poor prognostic predictive value was associated with surgical treatment, the overall survival was not different between patients who did or did not undergo surgery.

Cost-effectiveness of Balloon Kyphoplasty for Patients With Acute/Subacute Osteoporotic Vertebral Fractures in the Super-Aging Japanese Society.

STUDY DESIGN: A propensity score matching study. OBJECTIVE: The aim of this study was to assess the cost-effectiveness of balloon kyphoplasty (BKP) in Japan. SUMMARY OF BACKGROUND DATA: Osteoporotic vertebral fracture (OVF) is a common disease in elderly people. In Japan, the incidence of painful OVF in 2008 was estimated as 880,000, and approximately 40% of patients with painful OVF are hospitalized due to the severity of pain. Japan is the front runner among super-aged societies and rising health care costs are an economic problem. METHODS: BKP and nonsurgical management (NSM) for acute/subacute OVF were performed in 116 and 420 cases, respectively. Quality-adjusted life years (QALY) and incremental costs were calculated on the basis of a propensity score matching study. QALY was evaluated using the SF-6D questionnaire. Finally, using a Markov model, incremental cost-effectiveness ratios (ICERs) were calculated for 71 matched cases. RESULTS: In the comparison between BKP and NSM, mean patients age was 78.3 and 77.7 years, respectively (P = 0.456). The BKP procedure cost 402,988 JPY more than NSM and the gains in QALY at the 6-month follow-up were 0.153 and 0.120, respectively (difference = 0.033). ICERs for 3 and 20 years were 4,404,158 JPY and 2,416,406 JPY, respectively. According to sensitivity analysis, ICERs ranged from 652,181 JPY to 4,896,645 JPY (4418-33,168 GBP). CONCLUSION: This study demonstrated that BKP is a cost-effective treatment option for OVF in Japan. However, the effect might be blunted in patients aged > 80 years. Further research is necessary to elucidate the cost-effectiveness of BKP in this population. LEVEL OF EVIDENCE: 4.

Characteristic radiological findings for revision surgery after balloon kyphoplasty.

Balloon kyphoplasty (BKP) sometimes fails to improve patients' outcomes, with revision surgery, using anterior or posterior reconstruction, being required. The purpose of this study was to investigate the radiological risk factors of failure after BKP in the treatment of osteoporotic vertebral fractures (OVFs). This case-control study included 105 patients treated with single BKP and 14 patients  who required revision BKP. We evaluated radiological findings differentiating both groups, using plain radiography and computed tomography, before BKP. Angular flexion-extension motion was significantly greater in the revision than BKP group. While the frequency of pedicle fracture and posterior wall injury was not different between the groups, a split type fracture was more frequent in the revision group. Split type fracture had the highest adjusted odds ratio (OR) for revision (16.5, p = 0.018). Angular motion ≥14° increased the risk for revision surgery by 6-fold (p = 0.013), with endplate deficit having an OR of revision of 5.0 (p = 0.032). The revision rate after BKP was 3.8%, with split type fracture, greater angular motion and large endplate deficit being risk factors for revision. Treatment strategies for patients with these risk factors should be carefully evaluated, considering the inherent difficulties in performing revision surgery after BKP.

Development of a scoring system for predicting adjacent vertebral fracture after balloon kyphoplasty.

BACKGROUND CONTEXT: The incidence of adjacent vertebral fracture (AVFs) is reported to be 10%-38% after balloon kyphoplasty. However, no reports have established a system for prediction of AVF occurrence. PURPOSE: To establish a scoring system for predicting AVF occurrence after balloon kyphoplasty for osteoporotic vertebral fractures (OVFs). DESIGN: A prospective cohort study. PATIENT SAMPLE: Consecutive elderly patients aged 65 years and older who underwent balloon kyphoplasty for OVFs within 2 months after the onset. OUTCOME MEASURES: AVF was confirmed by X-ray. METHODS: From 2015 to 2017, 116 consecutive patients from 10 participating hospitals who underwent balloon kyphoplasty were enrolled in this study. Prior to study enrollment, each patient underwent plain X-ray, computed tomography (CT), and magnetic resonance imaging (MRI) of the thoracic and lumbar spine. Severity of pain was subjectively assessed using a visual analog scale (VAS) based on the average level of back pain that the patient had experienced in the preceding week. After enrollment, subjects underwent balloon kyphoplasty. Quality of life was evaluated using SF-36. Patients were followed up for at least 6 months. RESULTS: Of the 116 patients enrolled, 109 patients with all the required data at the time of enrolment and the 6-month follow-up were included in the study. A total of 32 patients (29%) showed AVFs within the 6-month follow-up. No significant differences were observed in each clinical outcome at 6-month follow-up, although higher VAS score for back pain at 1-month follow-up was observed in the AVF group (37.5) than in the non-AVF group (20.8, p<.001). Wedge angle of vertebrae before surgery was greater in the AVF group (21.6°) than in the non-AVF group (15.7°, p<.001). The change in wedge angle between pre- and postsurgery was greater in the AVF group than in the non-AVF group, whereas the change in local kyphosis was not significantly different. The multiple logistic regression model showed increased odds ratio (OR) of thoracic or thoracolumbar spine, old OVF presence, >25° kyphosis before surgery, and >10°correction for AVF. Based on this result, a simple scoring system for predicting AVF occurrence was developed. The total AVF score was calculated as the sum of the individual scores, which varied from 0 to 6. All patients with 5-6 points sustained AVF. CONCLUSIONS: More severe wedge angle before surgery, correction degree, old OVF presence, and thoracolumbar level were predictive factors for AVF. All patients with AVF risk score of 5 or more showed AVF. This information may aid preoperative risk assessment, informed shared decision-making, and consideration of potential alternative management strategies.