Prognostic factors in patients with metastatic spine tumors derived from lung cancer—a novel scoring system for predicting life expectancy

Abstract Background Recently, molecule-targeting and bone-modifying agents have improved the treatment outcomes of lung cancer-derived metastatic spine tumors. Therefore, the prognostic factors for such tumors were examined, and novel scoring systems for predicting the life expectancy of patients with such tumors were proposed. Methods In 207 patients with lung cancer-derived metastatic spine tumors (surgery 49; conservative therapy 158), we retrospectively examined the factors that influenced the post-treatment survival time (age, sex, the affected site, pathology, general condition, the number of extraspinal bone metastases, the number of spinal metastases, the presence/absence of major internal organ metastasis, paralysis state, the total Tokuhashi score, the serum alkaline phosphatase level, the serum carcinoembryonic antigen level, molecule-targeting drug treatment, and bone-modifying agent treatment). Based on the results, we devised novel scoring systems for predicting the prognosis of such patients. Results Univariate analyses showed that the pathology of the primary lung tumor, the patient’s general condition and paralysis state, and the presence/absence of molecule-targeting drug treatment significantly influenced survival. We performed a Cox regression analysis of these four factors and developed criteria for a novel scoring system based on the patient’s general condition and paralysis state, which exhibited significance in the regression analysis. A retrospective review indicated that the consistency rate between predicted life expectancy and actual survival was 67.3%. When criteria based on the four factors that exhibited significance in the univariate analyses were adopted, the consistency rate was 76.2%. Conclusion The patient’s general condition and paralysis state, the pathology of the primary lung tumor, and molecule-targeting drug treatment influenced survival among patients with lung cancer-derived metastatic spine tumors. Novel scoring systems based on these four factors were proposed

Classification and scoring systems for metastatic spine tumors: a literature review

Introduction: Accurate evaluation of metastasis and life prognosis is essential for selecting a suitable therapeutic strategy for metastatic spine tumors owing to limitations in treatment options. For this purpose, various classification, evaluation, and scoring systems have been developed. Methods: Classification, evaluation, and scoring systems for metastatic spine tumors reported to date were identified by performing a literature search on PubMed. We reviewed the most cited classifications and scorings before 2009, and all classifications and scorings reported after 2010 from the search results. Results: Six classifications and 23 scorings were reviewed. The classification/evaluation methods are divided into 1) anatomical classification/evaluation methods, 2) evaluation methods for neurological symptoms/instability, and 3) scoring systems for predicting life expectancy. The first 2 were useful for the planning and evaluation of surgical indications. Scoring systems for life prognosis also permitted rough prediction of the outcomes and were useful for the selection of a suitable treatment. However, variation of the patient background, diversity of adopted prognostic factors, and the absence of scoring systems that could predict the outcome with an accuracy of 90% or higher introduced some limitations. Conclusion: The identified classification, evaluation, and scoring systems have been generally useful for treatment strategies. However, we emphasize the necessity of multidisciplinary development and revision of classification and evaluation methods to adapt to the prolongation of survival associated with increased diversity and improvement of treatment options

Radiographic and clinical outcomes of C1-C2 intra-articular screw fixation in patients with atlantoaxial subluxation

Abstract Background The Magerl and Goel-Harms techniques have been reported to produce excellent treatment outcomes in cases of atlantoaxial subluxation, but they also carry a risk of vertebral artery injuries. In order to completely prevent such injuries, we developed a surgical procedure, involving bone grafting between the C1 posterior arch and C2 lamina with clamp- or hook-and-rod-based fixation combined with the insertion of an interference screw into the posterior atlantoaxial joint. Methods This was a retrospective single-center study. The subjects were 58 patients in whom atlantoaxial subluxation was treated with the abovementioned procedure after 1995 (33 patients with rheumatoid arthritis (RA group) and 25 patients without rheumatoid arthritis (non-RA group)). The clinical outcomes and imaging findings of anterior subluxation at ≥ 2 years after surgery were compared between the RA and non-RA groups. Results No vertebral artery injuries occurred during surgery. Seven and two patients died during the follow-up period in the RA and non-RA groups, respectively, but none of these deaths were associated with surgery. At ≥ 2 years after surgery, the visual analogue scale score, Japanese Orthopaedic Association score, and Ranawat classification had significantly improved in both groups (p < 0.001). Radiologically, bone fusion was noted in all patients. Significant changes in the atlas-dens interval (ADI) were seen immediately after surgery in both groups (p < 0.001). In the non-RA group, significant changes in the corrected atlantoaxial height were observed immediately after surgery (p < 0.01), and loss of correction was seen at the final follow-up, but it was not significant (p = 0.1965). No significant changes were noted in any other parameter. Regarding the postoperative alignment of the cervical spine, lordosis tended to decrease, but additional surgery was only performed in one patient, who had developmental stenosis at the mid-lower level and belonged to the RA group. No reoperations due to fused adjacent segmental disease or exacerbated curvature were required. Conclusion In the present study, no vertebral artery injuries occurred during surgery, and no major perioperative complications developed. Favorable clinical outcomes were observed at ≥ 2 postoperative years although the patients’ diseases varied. This procedure produced superior outcomes, especially in terms of spinal correction and the maintenance of the ADI

A Novel Pedicle Screw with Mobile Connection: A Pilot Study

To prevent adjacent disc problems after spinal fusion, a pedicle screw with a mobile junction between the head and threaded shaft was newly developed. The threaded shaft of the screw has 10 degrees mobility in all directions, but its structure is to prevent abnormal translation and tilting. This screw was evaluated as follows: (1) endurance test: 106 times rotational stress was applied; (2) biological reactions: novel screws with a mobile head and conventional screws with a fixed head were inserted into the bilateral pedicles of the L3, L4, and L5 in two mini pigs with combination. Eight months after surgery, vertebral units with the screw rod constructs were collected. After CT scan, the soft and bony tissues around the screws were examined grossly and histologically. As a result, none of the screws broke during the endurance test stressing. The mean amount of abrasion wear was 0.0338 g. In the resected mini pig section, though zygapophyseal joints between fixed-head screws showed bony union, the amount of callus in the zygapophyseal joints connected with mobile-head screws was small, and joint space was confirmed by CT. No metalloses were noted around any of the screws. Novel screws were suggested to be highly durable and histologically safe

Exploratory analysis of predictors of revision surgery for proximal junctional kyphosis or additional postoperative vertebral fracture following adult spinal deformity surgery in elderly patients: a retrospective cohort study

Abstract Background Proximal junctional kyphosis (PJK) following adult spinal deformity (ASD) surgery in elderly patients is markedly influenced by osteoporosis causing additional vertebral fracture and loosening of pedicle screws (PS). This study aimed to investigate the association between mean bone density represented in Hounsfield units (HU) on spinal computed tomography (CT) and revision surgery for PJK or postoperative additional vertebral fracture following ASD surgery in elderly patients. Methods The subjects were 54 ASD patients aged 65 years or older who were treated with correction and fusion surgery of four or more levels and could be followed for 2 years or longer. Bone density was measured before surgery using lumbar dual-energy X-ray absorptiometry (DXA) and spinal CT in all patients. The patients were divided into group A (n = 14) in which revision surgery was required for PJK or additional vertebral fracture and group B (n = 40) in which revision surgery was not required. We retrospectively investigated incidences of PJK, additional vertebral fracture, and PS loosening, perioperative parameters, radiographic parameters before and after surgery, and osteoporosis treatment administration rate. Results No significant difference was noted in young adult mean (YAM) on DXA between groups A and B, respectively (P = 0.62), but the mean bone densities represented in HU of the T8 (P = 0.002) and T9 (P = 0.01) vertebral bodies on spinal CT were significantly lower in group A, whereas those of the L4 (P = 0.002) and L5 (P = 0.01) vertebral bodies were significantly higher in group A. The incidence of PJK was not significantly different (P = 0.07), but the incidence of additional vertebral fracture was significantly higher in group A (P < 0.001). The incidences of uppermost PS loosening within 3 months after surgery were 71% and 40% in groups A and B, respectively (P = 0.04). Conclusions In elderly patients who required revision surgery, the mean bone densities of vertebral bodies at T8 and T9 were significantly lower. The mean bone density represented in HU on spinal CT may be useful for risk assessment of and countermeasures against revision surgery after ASD surgery in elderly patients

Clinical results of multidisciplinary therapy including palliative posterior spinal stabilization surgery and postoperative adjuvant therapy for metastatic spinal tumor

Abstract Background Surgeries performed for metastatic spinal tumor are mostly palliative and are controversial for patients with short life expectancy. We investigated whether palliative posterior spinal stabilization surgery with postoperative multidisciplinary therapy results in improvement of life prognosis and activities of daily living (ADL) in patients with metastatic spinal tumor. Methods The subjects were 55 patients who underwent palliative posterior-only instrumentation surgery for metastatic spinal tumor at our hospital between 2012 and 2015. Postoperative survival, early paralysis improvement, ADL improvement, and rate of discharge to home were examined. Results The patients included 37 males and 18 females, and the mean age at the time of surgery was 66.8 years old. The mean Tokuhashi score was 7.1, the mean spinal instability neoplastic score (SINS) was 9.4, and the epidural spinal cord compression scale (ESCCS) was grade 3 in 20 patients (36.3%). The mean Barthel index for ADL was 48.7. The median postoperative survival time determined using the Kaplan-Meier method was 12.0 months (95% confidence interval 2.4–21.5). Regarding improvement of paralysis, the modified Frankel scale was improved by one grade or more or grade E was maintained in 35 patients (63.6%), whereas paralysis aggravated in 2 (3.6%). In surgery, conventional posterior decompression and fixation were applied in 31 patients (56.3%), and minimally invasive spine stabilization was applied in 24 (43.6%). Postoperative chemotherapy was performed in 31 patients (56.3%), radiotherapy was used in 38 (69.0%), and a bone-modifying agent was administered in 39 (70.2%). Regarding ADL, the mean Barthel index improved from 48.5 before surgery to 74.5 after surgery. Thirty-seven patients (67.2%) were discharged to home. Conclusions ADL improved and allowed discharge to home, and postoperative adjuvant therapy could be administered at a high rate in patients who received palliative posterior spinal stabilization surgery. Survival time extended beyond the preoperative life expectancy in many patients. Patients with a metastatic spinal tumor have short life expectancy and paralysis caused by spinal instability and spinal cord compression. However, multidisciplinary therapy including palliative posterior spinal stabilization surgery with reduced invasiveness and postoperative adjuvant therapy are effective in these patients

Comparison between minimally invasive spine stabilization with and without posterior decompression for the management of spinal metastases: a retrospective cohort study

Abstract Background Posterior decompression and stabilization plays significant roles in palliative surgery for metastatic spinal tumor. However, the indication for addition of posterior decompression have not been examined. The purpose of this study was to investigate a retrospective cohort of outcomes of metastatic spinal tumor treated with minimally invasive spine stabilization (MISt) with or without posterior decompression. Methods The subjects were 40 patients who underwent MISt using percutaneous pedicle screws for metastatic spinal tumor, including 20 patients treated with stabilization alone (group A) and 20 patients with added posterior decompression (group B). We analyzed baseline characteristics, postoperative survival time, and perioperative factors such as neurological outcomes, Barthel Index, VAS, and rate of discharge to home. Results The mean ages were 70 and 66 years old (P = 0.06), the mean revised Tokuhashi scores were 7.2 and 5.8 (P = 0.1), the mean spinal instability neoplastic scores (SINS) were 10.5 and 9.0 (P = 0.04), and the mean Barthel Index for ADL were 65.5 and 41.0 (P = 0.06) in groups A and B, respectively. The median postoperative survival time did not differ significantly between groups A and B (12.0 vs. 6.0 months, P = 0.09). Patients in group A had a significantly shorter operation time (166 vs. 232 min, P = 0.004) and lower intraoperative blood loss (120 vs. 478 mL, P < 0.001). Postoperative paralysis (P = 0.1), paralysis improvement rate (P = 0.09), postoperative Barthel Index (P = 0.06), and postoperative VAS (P = 0.6) did not differ significantly between the groups. The modified Frankel classification improved from D1 or D2 before surgery to D3 or E after surgery in 4 of 10 cases (40%) in group A and 8 of 8 patients (100%) in group B (P = 0.01). Significantly more patients were discharged to home in group A (P = 0.02), whereas significantly more patients died in the hospital in group B (P = 0.02). Conclusions Patients treated without decompression had a shorter operation time, less blood loss, a higher rate of discharge to home, and lower in-hospital mortality, indicating a procedure with lower invasiveness. MISt without decompression is advantageous for patients with D3 or milder paralysis, but decompression is necessary for patients with D2 or severer paralysis

Clinical Results of Minimally Invasive Spine Stabilization for the Management of Metastatic Spinal Tumors Based on the Epidural Spinal Cord Compression Scale

Purpose. Minimally invasive spine stabilization (MISt) using percutaneous pedicle screws plays a significant role in palliative surgery for metastatic spinal tumors. However, few studies have investigated surgical outcomes based on the epidural spinal cord compression scale (ESCCS). The purpose of this study was to examine outcomes of metastatic spinal tumors as evaluated by ESCCS in patients treated by MISt. Methods. The subjects were 56 patients who underwent MISt for metastatic spinal tumors, including 34 patients with ESCCS 2 or milder (group A) and 22 patients with ESCCS 3 (group B). We analyzed baseline characteristics, perioperative factors and clinical results such as postoperative survival time, neurological outcomes, Barthel Index for activities of daily living (ADL), visual analogue scale (VAS), and the rate of discharge to home. Results. The baseline age (P=0.07), tumor diagnosis (P=0.23), spinal level of compression (P=0.35), American Spinal Injury Association classification (P=0.49), revised Tokuhashi score (P=0.92), spinal instability neoplastic score (P=0.28), VAS (P=0.35), Barthel Index (P=0.07), American Society of Anesthesiologists physical status classification (P=0.76), and type of surgery (P=0.40) did not differ significantly between the two groups. The median postoperative survival time did not differ significantly between the groups (12.0 versus 15.0 months, P=0.60). Neurological improvement by at least 1 grade or maintenance of grade E was favorable in group A. Patients in group A had less posterior decompression (P=0.006), a higher rate of chemotherapy (P=0.009), a higher postoperative Barthel Index (P=0.04), and a higher rate of discharge to home (P=0.01) and no patients died in the hospital (P=0.004). Conclusions. No significant difference was noted in the postoperative survival time between the 2 groups. Patients in the ESCCS 2 or milder group had favorable neurological improvement, higher rates of chemotherapy, better postoperative ADL, and the higher rate of discharge to home