Results of Using a Novel Percutaneous Pedicle Screw Technique for Patients with Diffuse Idiopathic Skeletal Hyperostosis-The Single or Double Endplates Penetrating Screw (SEPS/DEPS) Technique.

INTRODUCTION: We have developed the single or double endplates penetrating screw (SEPS/DEPS) technique, which is a novel percutaneous pedicle screw (PPS) insertion technique suitable for osteoporotic vertebral body fracture (OVF) patients with diffuse idiopathic skeletal hyperostosis (DISH). This study aims to compare the effectiveness of this SEPS/DEPS technique with the conventional pedicle screw technique. METHODS: The screw is inserted upward from the outer caudal side of the pedicle toward the inner cranial side. Vertebrae affected with DISH were inserted with screws using the SEPS/DEPS technique, whereas non-fused vertebrae were inserted with screws using the conventional PPS technique. Twelve OVF patients with DISH were included in this study; three with SEPS/DEPS technique only and nine with a hybrid of both the DEPS and the conventional PPS techniques. As a control group, 12 OVF patients with DISH treated by conventional PPS. The rates of implant failures and of surgical complications were compared between the SEPS/DEPS group and the control group. The insertion torque was measured and compared between DEPS and conventional PPS in three hybrid patients. RESULTS: In the SEPS/DEPS group, 70 screws were inserted with the SEPS/DEPS technique and 56 screws were inserted with the conventional PPS technique. In the control group, 116 screws were inserted using the conventional PPS and the PS techniques. The loosening of screws was significantly less in screws inserted with the SEPS/DEPS technique (0/70 screws, 0%) than with screws inserted with the conventional technique (12/116 screws, 10.3%). The average insertion torque of DEPS was 2.25 Nm, which was 134% higher than that of conventional PPS which was 1.64 Nm (p = 0.04). CONCLUSIONS: This novel SEPS/DEPS technique has a higher insertion torque compared with the conventional PPS techniques and demonstrated itself to be an effective option for patients with concomitant bone fragility due to DISH.

Mechanism of forelimb motor function restoration in rats with cervical spinal cord hemisection-neuroanatomical validation.

PURPOSE: The purpose of this study is neuroanatomical validation of forelimb motor function restoration in rats with cervical spinal cord injury. MATERIALS AND METHODS: We used eight cervical hemisected rats and eight normal rats. We cut in half the C3/4 cervical spinal cord of 18-weeks-old normal rats. We used 24-weeks-old rats that had reached a nearly steady state of forelimb motor function after the hemisection (Hemisection group). Normal 24-week-old rats were used as Control group. To evaluate the corticospinal tracts, neuro-tracing by biotynirated dextran-amine (BDA) was used. BDA was injected into the damaged side of the cerebral primary motor cortex. In order to quantitatively analyze the specimen, we recorded a site where nerve fibers appear in each specimen in the image analysis (1) and defined the increase rate of immunostaining area using ImageJ in the image analysis (2). Based on the evaluation in the image analysis (1) and the image analysis (2), the Hemisection group and the Control group were compared. RESULTS: In the image analysis (1), a region with robust appearance of aberrant nerve fibers was observed in the cephalad side of the Hemisection site in Hemisection group than Control group. In the spinal cord caudal to the hemisection, such region was generally more in Hemisection group, however, disappeared or reduced appearance was observed in some regions. In the image analysis (2), no statistical significant difference was noted in each level. CONCLUSION: There is a high probability that these aberrant nerve fibers beyond the midline could be involved in forelimb motor function restoration in rats with cervical cord hemisection.

Corrigendum to "Mechanism of Restoration of Forelimb Motor Function after Cervical Spinal Cord Hemisection in Rats: Electrophysiological Verification".

[This corrects the article DOI: 10.1155/2017/7514681.].

Potential asbestos exposure among patients with primary lung cancer in Japan.

OBJECTIVE: To investigate the extent of asbestos exposure among patients with primary lung cancer in Japan. METHODS: A retrospective estimation of potential asbestos-exposed individuals, as determined by the presence of pleural plaques identified on chest computed tomography (CT), was conducted on 885 pathologically confirmed primary lung cancer patients (mean age 71.3 years, 641 males). All patients were diagnosed at 29 hospitals across Japan between 2006 and 2007. Since these hospitals belong to the Japan Federation of Democratic Medical Institutions (MIN-IREN), an organization of medical institutions for workers, the study subjects may contain a higher proportion of workers than the general population. RESULTS: Pleural plaques were identified in 12.8% of subjects (15.8% in males and 4.9% in females), consisting exclusively of cases older than 50 years. They were found most frequently on the chest wall pleura (96.5%), followed by the diaphragm (23.9%) and mediastinum (9.7%). Calcifications were seen in 47 cases (41.6%). The highest prevalence of pleural plaques was seen among workers from construction-related fields (37.7%). No distinct lung cancer histology was observed in patients with pleural plaques. Coexistence of pleural plaques and small irregular opacities was observed in 2.5% of subjects. CONCLUSION: In a Japanese population representing more workers than general Japanese, 12.8% of patients with primary lung cancer may have experienced asbestos exposure at some time in the past. Special medical attention should be paid to individuals with a history of employment in construction-related occupations, as workers in this sector showed the highest prevalence of pleural plaques.

Mechanism of Restoration of Forelimb Motor Function after Cervical Spinal Cord Hemisection in Rats: Electrophysiological Verification.

The objective of this study was to electrophysiologically assess the corticospinal tracts of adult rats and the recovery of motor function of their forelimbs after cervical cord hemisection. Of 39 adult rats used, compound muscle action potentials (CMAPs) of the forelimbs of 15 rats were evaluated, before they received left C5 segmental hemisection of the spinal cord, by stimulating the pyramid of the medulla oblongata on one side using an exciting microelectrode. All 15 rats exhibited contralateral electrical activity, but their CMAPs disappeared after hemisection. The remaining 24 rats received hemisection first, and CMAPs of 12 rats were assessed over time to study their recovery time. All of them exhibited electrical activity of the forelimbs in 4 weeks after surgery. The remaining 12 rats received additional right C2 segmental hemisection, and variation of CMAPs between before and after surgery was examined. The right side of the 12 rats that received the additional hemisection exhibited no electrical activity in response to the stimulation of the pyramids on both sides. These results suggest that changes in path between the resected and healthy sides, activation of the ventral corticospinal tracts, and propriospinal neurons were involved in the recovery of motor function after cervical cord injury.

Postoperative Paralysis From Thoracic Ossification of Posterior Longitudinal Ligament Surgery Risk Factor of Neurologic Injury: Nationwide Multiinstitution Survey.

STUDY DESIGN: Retrospective case-control study. OBJECTIVE: The purpose of this study was to examine the factors of postoperative paralysis in patients who have undergone thoracic ossification of posterior longitudinal ligament (OPLL) surgery. SUMMARY OF BACKGROUND DATA: A higher percentage of thoracic OPLL patients experience postoperative aggravation of paralysis than cervical OPLL patients, including patients that presented great difficulties in treatment. However, there were a few reports to prevent paralysis thoracic OPLL. METHODS: The 156 patients who had received thoracic OPLL surgery were selected as the subjects of this study. The items for review were the duration of disease; the preoperative muscle strength (Muscle Manual Testing); OPLL levels (T1/2-4/5: high, T5/6-8/9: middle, and T9/10-11/12: low); the spinal canal occupancy ratio; the ratio of yellow ligament ossification as a complication; the ratio of transcranial-motor evoked potential (Tc-MEP) derivation; the preoperative/postoperative kyphotic angles in the thoracic vertebrae; the correction angle of kyphosis; the duration of surgery; and the amount of bleeding. The subjects were divided into two groups based on the absence or presence of postoperative paralysis to determine the factors of postoperative paralysis. RESULTS: Twenty-three patients (14.7%) exhibited postoperative paralysis. Multivariate analysis identified factors associated with postoperative paralysis: the duration of disease (odds ratio, OR = 3.3); the correction angle of kyphosis (OR = 2.4); and the ratio of Tc-MEP derivation (OR = 2.2). CONCLUSION: The risk factors of postoperative paralysis are a short duration of disease and a small correction angle of kyphosis. In addition, ratios of Tc-MEP derivation below 50% may anticipate paralysis. LEVEL OF EVIDENCE: 4.

Mechanism of Forelimb Motor Function Restoration after Cervical Spinal Cord Hemisection in Rats: A Comparison of Juveniles and Adults.

The aim of this study was to investigate forelimb motor function after cervical spinal cord injury in juvenile and adult rats. Both rats received a left segmental hemisection of the spinal cord after C3-C4 laminectomy. Behavioral evaluation of motor function was monitored and assessed using the New Rating Scale (NRS) and Forelimb Locomotor Scale (FLS) and by measuring the range of motion (ROM) of both the elbow and wrist. Complete left forelimb motor paralysis was observed in both rats. The NRS showed motor function recovery restored to 50.2 ± 24.7% in juvenile rats and 34.0 ± 19.8% in adult rats. FLS was 60.4 ± 26.8% in juvenile rats and 46.5 ± 26.9% in adult rats. ROM of the elbow and wrist were 88.9 ± 20.6% and 44.4 ± 24.1% in juvenile rats and 70.0 ± 29.2% and 40.0 ± 21.1% in adult rats. Thus, the NRS and ROM of the elbow showed a significant difference between age groups. These results indicate that left hemisection of the cervical spinal cord was not related to right-sided motor functions. Moreover, while motor paralysis of the left forelimb gradually recovered in both groups, the improvement was greater in juvenile rats.

What Is the Best Multimodality Combination for Intraoperative Spinal Cord Monitoring of Motor Function? A Multicenter Study by the Monitoring Committee of the Japanese Society for Spine Surgery and Related Research.

Study Design Surgeon survey. Objective To analyze multimodal intraoperative monitoring (MIOM) for different combinations of methods based on the collected data and determine the best combination. Methods A questionnaire was sent to 72 training institutions to analyze and compile data about monitoring that had been conducted during the preceding 5 years to obtain data on the following: (1) types of monitoring; (2) names and number of diseases; (3) conditions of anesthesia; (4) condition of stimulation, the monitored muscle and its number; (5) complications; and (6) preoperative and postoperative manual muscle testing, presence of dysesthesia, and the duration of postoperative motor deficit. Sensitivity and specificity, false-positive rates, and false-negative rates were examined for each type of monitoring, along with the relationship between each type of monitoring and the period of postoperative motor deficit. Results Comparison of the various combinations showed transcranial electrical stimulation motor evoked potential (TcMEP) + cord evoked potential after stimulation to the brain (Br-SCEP) combination had the highest sensitivity (90%). The TcMEP + somatosensory evoked potential (SSEP) and TcMEP + spinal cord evoked potential after stimulation to the spinal cord (Sp-SCEP) combinations each had a sensitivity of 80%, exhibiting little difference between their sensitivity and that obtained when TcMEP alone was used. Meanwhile, the sensitivity was as low as 50% with Br-SCEP + Sp-SCEP (i.e., the cases where TcMEP was not included). Conclusions The best multimodality combination for intraoperative spinal cord monitoring is TcMEP + Br-SCEP, which had the highest sensitivity (90%), the lowest false-positive rate (6.1%), and the lowest false-negative rate (0.2%).

Development of Stemness in Cancer Cell Lines Resistant to the Anticancer Effects of Zoledronic Acid.

BACKGROUND: Drug resistance is closely related to cancer cell stemness, that is acquired along with resistance to various anticancer agents. However, this has not been investigated as a potential mechanism underlying cancer cell resistance to zoledronate, that is used to suppress bone metastasis. MATERIALS AND METHODS: Zoledronate-resistant A549 lung cancer and MG63 osteosarcoma cell lines were established by repeated treatment with sub-lethal concentrations of zoledronate. Expression levels of the stem cell marker NANOG, cMYC, octamer-binding transcription factor 4, and sex-determining region Y-box 2 were evaluated and sphere formation was compared between parental and resistant cell lines. Tumourigenicity was assessed in vivo. RESULTS: Stem cell marker expression was up-regulated and sphere formation was enhanced in resistant compared to parental cells and showed greater tumour formation capacity in mice. CONCLUSION: Repeated treatment of malignant tumour cell lines with zoledronate, induces the development of drug resistance and stemness.

Physical Function Traits of Long-term Officially Acknowledged Victims of Pollution-related Illnesses Compared with Elderly Patients with Chronic Obstructive Pulmonary Disease.

[Purpose] To examine the long-term effects of air pollution on the physical functioning of a group of officially acknowledged victims of pollution-related illnesses (Victims group) who were exposed to air pollution more than 50 years ago, we compared them with age-matched patients with chronic obstructive pulmonary disease (COPD group). [Subjects and Methods] The Victims group comprised 34 subjects and the COPD group 24, all of whom were aged over 65 years. Respiratory function, muscle strength, exercise capacity and physical activity were measured and compared between the groups. [Results] The Victims group had significantly higher forced expiratory volume in the first second (FEV1), proportion of predicted FEV1, proportion of predicted vital capacity (VC), and ratio of FEV1 to forced VC than the COPD group. Surprisingly, the muscle strength of the Victims group was significantly weaker, their incremental shuttle walking test distance was significantly shorter, and their physical activity was significantly less than those of the COPD group. [Conclusion] Although the pulmonary function of Victims was better than that of the COPD group, their physical functioning was worse. Exposure to air pollution 50 years ago appears to continue to adversely affect their physical function. It is particularly important to offer Victims rehabilitation to improve their exercise performance and physical activity.

D-dimer levels in the differential diagnosis between lipoma and well-differentiated liposarcoma.

BACKGROUND: Lipoma and well-differentiated liposarcoma (WDLS) are two representative lipogenic soft tissue tumors that have similar clinical, radiological, and pathological characteristics. Accordingly, it is difficult to distinguish these tumors preoperatively. Plasma D-dimer levels are associated with the status of tumor progression, and we hypothesized that D-dimer levels could contribute to differential diagnosis. The D-dimer levels of these two entities have not yet been reported. PATIENTS AND METHODS: We investigated 43 cases of lipoma and 14 cases of WDLS. We evaluated the utility of D-dimer levels and other clinicopathological factors for preoperative differential diagnosis between the two entities. RESULTS: Receiver operating characteristic analysis revealed that the D-dimer level may contribute to differential diagnosis (area under the curve=0.73). Univariate and multivariate models demonstrated that plasma D-dimer levels (p=0.001 (univariate), and p=0.006 (multivariate)) and lower extremity location (p=0.006 (univariate), and p=0.03 (multivariate)) were independent risk factors for WDLS. CONCLUSION: The D-dimer level may be a helpful marker for preoperative differential diagnosis between lipoma and WDLS.

A new alarm point of transcranial electrical stimulation motor evoked potentials for intraoperative spinal cord monitoring: a prospective multicenter study from the Spinal Cord Monitoring Working Group of the Japanese Society for Spine Surgery and Related Research.

OBJECT: Although multimodal intraoperative spinal cord monitoring provides greater accuracy, transcranial electrical stimulation motor evoked potential (TcMEP) monitoring became the gold standard for intraoperative spinal cord monitoring. However, there is no definite alarm point for TcMEPs because a multicenter study is lacking. Thus, based on their experience with 48 true-positive cases (that is, a decrease in potentials followed by a new neurological motor deficit postoperatively) encountered between 2007 and 2009, the authors set a 70% decrease in amplitude as the alarm point for TcMEPs. METHODS: A total of 959 cases of spinal deformity, spinal cord tumor, and ossification of the posterior longitudinal ligament (OPLL) treated between 2010 and 2012 are included in this prospective multicenter study (18 institutions). These institutions are part of the Japanese Society for Spine Surgery and Related Research monitoring working group and the study group on spinal ligament ossification. The authors prospectively analyzed TcMEP variability and pre- and postoperative motor deficits. A 70% decrease in amplitude was designated as the alarm point. RESULTS: There were only 2 false-negative cases, which occurred during surgery for intramedullary spinal cord tumors. This new alarm criterion provided high sensitivity (95%) and specificity (91%) for intraoperative spinal cord monitoring and favorable accuracy, except in cases of intramedullary spinal cord tumor. CONCLUSIONS: This study is the first prospective multicenter study to investigate the alarm point of TcMEPs. The authors recommend the designation of an alarm point of a 70% decrease in amplitude for routine spinal cord monitoring, particularly during surgery for spinal deformity, OPLL, and extramedullary spinal cord tumor.

Lung cancer cell line sensitivity to Zoledronic acid is BAX-dependent.

BACKGROUND: Zoledronate (Zol), an anti-osteoclastic and anticancer drug, is used to control bone metastasis in several cancer types, including non-small cell lung cancer (NSCLC). However, the mechanisms behind Zol resistance in NSCLC are unclear. MATERIALS AND METHODS: Zol-resistant cell lines were developed by repeated treatment of A549 and H1650 NSCLC cell lines with Zol. We measured cell proliferation and apoptosis following Zol treatment and also examined the BCL2 superfamily expression. RNAi was used to confirm the role of key molecules in development of resistance. RESULTS: Repeated Zol treatment engendered resistance, in which apoptosis induction was attenuated. From the BCL2 superfamily, BAX was commonly down-regulated in resistant cells, and silencing of BAX in parental cell lines also induced drug resistance. CONCLUSION: Repeated treatment of NSCLC cell lines with Zol leads to drug resistance, which is in part due to BAX down-regulation.

Usefulness of multi-channels in intraoperative spinal cord monitoring: multi-center study by the Monitoring Committee of the Japanese Society for Spine Surgery and Related Research.

OBJECT: The purpose of this study is to analyze the data in terms of the number of channels employed to examine the usefulness of multi-channels in intraoperative spinal cord monitoring. METHODS: The prerequisites for inclusion in the baseline data were as follows: (1) cases in which only CMAP monitoring was conducted; (2) cases in which monitoring was conducted under the same stimulation condition and the recording condition. Cases where inhalation anesthesia was used or muscle relaxants were used as maintenance anesthesia was excluded from the baseline data. Of the 6,887 cases, 884 cases met the criteria. The items examined for each of the different numbers of channels were the sensitivity and specificity, the false positive rate, the false negative rate, and the coverage rate of postoperative motor deficit muscles. RESULT: To examine these two items in terms of the number of channels, the 4-channel group had lower sensitivity and specificity scores compared with the 8- and 16-channel groups (4 channels 73/93 %, 8 channels 100/97 %, 16 channels 100/95 %). Only four channels were derived for these cases and the coverage of postoperative motor deficit muscles was 38 % with only 30 out of the 80 postoperative motor deficit muscles in total being monitored. In the 8-channel group, it was 60 % with 12 of the 20 postoperative motor deficit muscles being monitored. The 16-channel group had 100 % coverage rate of postoperative motor deficit muscles. CONCLUSION: We suggest that multi-channel monitoring of at least eight channels is desirable for intraoperative spinal cord monitoring.

Surgical site infection in malignant soft tissue tumors.

BACKGROUND: Postoperative wound complications, including surgical site infections, which frequently occur in the course of management of musculoskeletal sarcomas, sometimes necessitate repeat surgeries, including amputation, and may result in a prolonged healing time, prolonged hospital stay, or fatal outcome. A comprehensive understanding of surgical site infections associated with specific diseases is needed to reduce the risk. METHODS: This series comprised 84 patients with malignant soft tissue tumors treated at our institute. The occurrence rate, management modality and clinical course of surgical site infections, impact of surgical site infections on the length of hospitalization, risk factors for the development of surgical site infections, and the impact of surgical site infections on the oncological outcomes were analyzed. Surgical site infection was defined according to Centers for Disease Control and Prevention guidelines. RESULTS: Surgical site infections occurred in 7 cases (8.3%). Although successful clinical cure was achieved in all cases, surgical site infection was identified as one of the independent risk factors for prolongation of hospitalization. Both univariate and multivariate analyses identified larger intraoperative blood loss and a trunk location as risk factors associated with deep infections. No association was detected between age, tumor grade, chemotherapy, tumor volume, or plastic surgery and the risk of surgical site infections. Although the differences were not statistically significant, patients with surgical site infections showed worse oncological outcomes in terms of local recurrence and total survival. CONCLUSION: The incidence rate of surgical site infection was larger than that associated with conventional orthopedic surgeries, such as osteosynthesis, spine surgery, or arthroplasty. Surgical site infections remain a critical and frequent complication of surgical treatment of soft-tissue malignancies and often result in prolongation of hospital stay. Although practical options to prevent surgical site infections seem quite limited, the present data provide a rationale for perioperative evaluation in patients at a high risk of surgical site infections.

D-dimer levels as a prognostic factor for determining oncological outcomes in musculoskeletal sarcoma.

BACKGROUND: Plasma d-dimer levels have been associated with the status of tumor progression or oncological outcomes in cancer. Although there are many evidences suggesting the involvement of procoagulant trend in musculoskeletal sarcoma, no clinical data on d-dimer levels and oncological outcome of musculoskeletal sarcoma has been reported. METHODS: In this study, we included a total of 85 patients who were diagnosed with musculoskeletal sarcoma and treated at our institute. Plasma d-dimer levels were determined before performing any clinical intervention, including open biopsy, chemotherapy, radiotherapy or tumor resection. We evaluated the effect of d-dimer levels and other clinicopathological factors on oncological outcomes of patients. RESULTS: Upregulation of plasma d-dimer levels proved to be an independent risk factor for metastasis and lethal outcome of patients with musculoskeletal sarcoma. CONCLUSIONS: Upregulation of plasma d-dimer levels were indicated poor oncological outcome in metastasis and total survival rate of musculoskeletal sarcoma patients. Hence d-dimer levels may be a helpful marker for evaluating the tumor progression status and prognosis of musculoskeletal sarcoma.

Functional assessment of proximal arm muscles by target-reaching movements in patients with cervical myelopathy.

BACKGROUND CONTEXT: In animal studies, distal and proximal arm movements are differently affected by spinal pyramidotomy because of the contributions of spinal interneuronal systems. In animals, interneuronal systems are also suggested to contribute to the recovery of dexterous hand movements. However, no clinical tests to evaluate proximal arm movements and functions of interneuronal systems have been described. PURPOSE: To compare parameters from proximal arm movements between patients and controls and in patients before and after decompression surgery. STUDY DESIGN: A cross-sectional and longitudinal study performed at Kyorin University School of Medicine, Japan. PATIENT SAMPLE: Patients with clinical features of cervical spondylotic myelopathy, without coexisting neurological abnormality. METHODS: Twenty-eight patients and 15 age-matched controls performed reach-to-touch movements. Analysis of these movements identified several parameters, including time for online correction (correction time) induced by sudden target jump. Parameters were compared with scores from conventional tests, such as Japanese Orthopedic Association (JOA) score, 10-second grip-and-release test, manual muscle testing, and motor-evoked potential. RESULTS: Preoperatively, patients showed long correction time and variable touch position, neither of which correlated with any scores from conventional tests. Reaching parameters recovered markedly immediately after decompression surgery, whereas conventional scores, which mainly assess hand functions, recovered much more slowly. Correction time and JOA score showed correlations when postoperative data were included, and long-term recovery of JOA score was more predictable with the inclusion of data for correction times from before and immediately after surgery. CONCLUSION: Analysis of arm movements is useful to evaluate symptoms and predict recovery of hand functions after surgery in patients with cervical myelopathy. These results suggest the importance of interneuronal systems, in addition to the pyramidal tract, for motor control even in humans.

Malignant pigmented villonodular synovitis in the knee - report of a case with rapid clinical progression.

Malignant pigmented villonodular synovitis (PVNS) (or malignant giant cell tumor of tendon sheath (GCTTS) is an extremely rare condition defined as a malignant lesion occurring with concomitant or previously documented PVNS at the same site. To date, only less than 20 cases have been reported in English literatures. We report a case of malignant PVNS in the knee in a 56-year-old woman with unpredictable rapid progression. This case raised a caution that when atypical components in specimens of recurrent benign PVNS are detected, even if low-grade or tiny, both pathologists and surgeons should consider the risk of malignant PVNS, which could display aggressive clinical progression.

Venous thromboembolism in the management of patients with musculoskeletal tumor.

BACKGROUND: Although patients with musculoskeletal tumors are at risk of venous thromboembolism (VTE), few detailed studies on the incidence, clinical course, and risk factors of this condition have been reported. METHODS: A total of 299 patients with musculoskeletal tumors during the preceding 3 years were enrolled. D-dimer (DD) levels on admission and on postoperative days 1, 7, and 14 were routinely assessed. For patients who were receiving chemotherapy, an examination was performed every 2-3 days for the survey. Multidetector-row computed tomography (MDCT) was used for the detection of VTE in patients with DD levels > 10 µg/ml. The incidence of clinically detected VTE and the clinical courses of the patients with VTE were reviewed. The risk factors for VTE were analyzed. For statistical analysis, Fisher's exact test, the Mann-Whitney U-test, and logistic regression were used. RESULTS: VTE was detected in eight cases (2.7%). Six cases were detected postoperatively, and the remaining two cases were detected during chemotherapy. Pulmonary embolism was evident in four cases. No VTE-related lethal events were detected during the study period. In the univariate analysis, malignancy (P = 0.003), chemotherapy (P = 0.004), plastic surgery (P = 0.006), tumor size (P = 0.008), and elevated DD levels at admission (P = 0.03) were found to be significant risk factors for VTE. Among these factors, the multivariate analysis indicated that tumor size (P = 0.00 006), plastic surgery (P 0. 01), and chemotherapy (P = 0.02) were independent risk factors. CONCLUSIONS: The incidence and risk factors for VTE in the management of musculoskeletal tumor patients by screening DD levels combined with MDCT were analyzed. For patients at risk, prospective surveys for VTE should be considered in the future.