Search

The article describes cases of ligamentum flavum hematoma (LFH) in the lumbar spine in four patients. These patients underwent en bloc excision of their ligamentum flavum. Results of the magnetic resonance imaging (MRI) of the patients showed epidural masses which connected a mass and ligamentum flavum. It is reported that the treatment of LFH in these patients was surgical. It also noted that LFH cannot be diagnosed without both intraoperative and pathological findings.

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The objective of this study was to electrophysiologically assess corticospinal tracts of adult rats and recovery of motor function of their forelimbs after cervical cord hemisection. Of 39 adult rats used, compound muscle action potentials (CMAPs) of forelimbs of 15 rats were evaluated, before they received left C5 segmental hemisection of the spinal cord, by stimulating the pyramid of 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 forelimbs in four 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 pyramids on both sides. These results suggest that changes in path between the resected and healthy sides, activation of ventral corticospinal tracts, and propriospinal neurons were involved in the recovery of motor function after cervical cord injury. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Abstract: 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. [Copyright &y& Elsevier]

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. [ABSTRACT FROM AUTHOR]

Background: Lethal events represent the most important complication in the treatment of hip fracture in elderly patients. Despite the increasing chance for treatment of such conditions, few data regarding risk factors associated with lethal events have been determined for ordinary hospitals with limited medical and human resources, particularly in Japan. Methods: The incidence of postoperative lethal events and related preoperative risk factors in extremely elderly patients (>80 years) with hip fracture were retrospectively analyzed in our hospital for the past 2 years. Results: Lethal events occurred in 11 (10.7%) of 103 patients within 3 months postoperatively. In both univariate and multivariate analyses, an elevated number of co-morbidities and preoperative respiratory dysfunction were identified as significant risk factors. Delay in surgery was not a risk factor for lethal events. Conclusions: A valid reason for delay is the need to stabilize concurrent medical conditions due to multiple co-morbidities in extremely elderly patients with hip fracture. Considering the limited resources and extreme age of the subjects, the mortality rate in the present study was quite acceptable. Patients, families of patients, and physicians should recognize the increased risk of mortality for patients with significant risk factors in the surgical treatment of hip fracture. [ABSTRACT FROM AUTHOR]

Although deep infection remains one of the most difficult complications to manage in the treatment of musculoskeletal tumor reconstructed with an endoprosthesis, limited information with respect to its incidence and risk factors has been reported. This multicenter, retrospective, uncontrolled study reviewed the medical records of 82 patients who underwent reconstruction with an endoprosthesis or temporary spacer for bone-immature patients after resection of malignant bone tumor around the knee. Risk factors for deep infection and the impact of deep infection on prosthesis survival and oncological outcomes were analyzed. Deep infection was defined according to the Centers for Disease Control and Prevention (CDC) guidelines with minor modification. Deep infection occurred in 14 cases (17%), identified at a mean of 10.9 months (range <1 to 48 months) after initial surgery. Univariate analysis identified surface infection ( P < 0.001) and skin necrosis ( P < 0.001) as risk factors associated with deep infection. Conversely, tumor origin, chemotherapy, number of postoperative antibiotics, and length of bone resection were not associated with infection. Subclass analysis in femur cases identified a correlation between infection and the extent of partial resection of the quadriceps muscle ( P = 0.04). In the multivariate analysis, surface infection represented an independent risk factor for deep infection ( P = 0.03). Deep infection was a risk for endoprosthesis survival ( P = 0.003) but did not affect the oncological outcome. A strong correlation between the condition of soft tissue and establishment of deep infection is suggested in this study. Although practical options for preventing deep infection seem limited, the present data allow a form of perioperative evaluation for patients with a higher risk of deep infection. [ABSTRACT FROM AUTHOR]

Background: Simple curettage for enchondroma without augmentation, known to lead to spontaneous bone consolidation at the curettage site, is a potential standard treatment for this condition. However, few detailed data comparing the results of this technique with conventional methods including reconstruction are available, and the relation between the postoperative completion period for bone consolidation and preoperative independent variables is not known. Methods: The subjects included 38 patients with enchondroma treated with simple curettage without augmentation. A historical group of patients with enchondroma treated with hydroxyapatite reconstruction was enrolled as controls. Treatment outcomes, including perioperative complications (e.g., infection, functional loss, recurrence, postoperative fracture), were surveyed. Differences in the period needed for bone formation among the patient groups defined by various preoperative patient conditions were also analyzed. Results: The follow-up period ranged from 12 to 60 months (average 24.3 months). During the follow-up period, no surgery-related complications occurred. Bone formation was confirmed in all cases 3–20 weeks (average 6.5 weeks) postoperatively. Tumor size represented by two-dimensional measurements was significantly correlated with the bone formation period. Polycystic lesions required a prolonged postoperative bone formation period compared with monocystic lesions. The bone formation period did not significantly differ between the simple curettage group and the historical control group. Conclusions: Simple curettage without augmentation proved to be a safe, promising modality for the treatment of small enchondromas in the hand and foot. [ABSTRACT FROM AUTHOR]

No clinical diagnostic support tool can help identify patients with LSS. Simple diagnostic tool may improve the accuracy of the diagnosis of LSS. The aim of this study was to develop a simple clinical diagnostic tool that may help physicians to diagnose LSS in patients with lower leg symptoms. Patients with pain or numbness of the lower legs were prospectively enrolled. The diagnosis of LSS by experienced orthopedic specialists was the outcome measure. Multivariable logistic regression analysis identified factors that predicted LSS; a simple clinical prediction rule was developed by assigning a risk score to each item based on the estimated beta-coefficients. From December 2002 to December 2004, 104 orthopedic physicians from 22 clinics and 50 hospitals evaluated 468 patients. Two items of physical examination, three items of patients' symptom, and five items of physical examination were included in the final scoring system as a result of multiple logistic regression analysis. The sum of the risk scores for each patient ranged from −2 to 16. The Hosmer–Lemeshow statistic was 11.30 ( P = 0.1851); the area under the ROC curve was 0.918. The clinical diagnostic support tool had a sensitivity of 92.8% and a specificity of 72.0%. The prevalence of LSS was 6.3% in the bottom quartile of the risk score (−2 to 5) and 99.0% in the top quartile (12 to 16). We developed a simple clinical diagnostic support tool to identify patients with LSS. Further studies are needed to validate this tool in primary care settings. [ABSTRACT FROM AUTHOR]

Abstract: Background: Little is known about the mechanism of the paraplegia produced by metastatic spinal tumors, although the quality of life of patients with paraplegia caused by malignant tumors depends to a great extent on treatment of the paraplegia. We previously established an experimental model of malignant femoral tumors by transplanting VX2 carcinoma into the femur, and we have reported the efficacy of chemical embolic therapy, radiotherapy and hyperthermal therapy in treating the tumors in the model. Purpose: The purpose of the present study was to establish an animal model of metastatic spinal tumors by transplanting VX2 carcinoma into a pedicle and to analyze the mechanism of the paraplegia produced by metastatic spinal tumors. Study design: An experimental study. Methods: VX2 carcinoma that had been successively transplanted to the thigh muscles of Japanese White rabbits in the Department of Orthopaedic Surgery of Kyorin University School of Medicine was used. The third lumbar vertebra of 37 healthy rabbits was exposed, and a piece of VX2 carcinoma was transplanted into a hole created in the pedicle with an air drill after transplantation. The animals were examined every other day. As soon as paraplegia developed, the animals were sacrificed, and the axial localization of the tumor was evaluated based on the surgical staging of the spinal tumor (SSST classification by Tomita). Roentgenographic, histological and angiographic studies were also performed. Results: Twenty-two rabbits (60%) had paraplegia at the time of the final examination. Seventeen of them had complete paraplegia, and the other five had incomplete paraplegia. The average interval until incomplete paraplegia developed was 18.4±4.3 days, and the average interval until complete paraplegia developed was 30.0±4.3 days. The average proportion of the diameter of the spinal canal occupied by the tumor was 37.2±4.9% in the incomplete cases, and 70.6% in the complete cases. The radiographs revealed an osteolytic area in the pedicle and posterior border of the third lumbar vertebra in the rabbits with complete paraplegia, but no osteolytic areas were detected in the rabbits with incomplete paraplegia. According to the SSST classification, the lesions of all of the rabbits with paraplegia were classified as stage IV. Pathological studies revealed that the spinal cord generally exhibited degenerative change, especially at the site of tumor compression. No tumor cells had invaded the spinal cord. Microangiography showed a marked reduction in blood vessels in the gray matter of the spinal cord in the complete paraplegia in comparison with incomplete paraplegia. Conclusion: Our method succeeded in establishing a model of metastatic spinal tumors, because the natural history of the disease, including the anatomical location of the tumors and the imaging findings, was similar to the natural history in clinical cases. This model was useful for elucidating the pathogenetic mechanism of the paraplegia caused by metastatic spinal tumors. [Copyright &y& Elsevier]

The article presents an analysis on radiographic predictors for the development of myelopathy in patients with ossification of the posterior longitudinal ligament (OPLL). A study conducted in 156 patients with OPLL revealed the evolution of myelopathy positively correlated with less than sixty percent canal stenosis, greater range of motion, as well as lateral deviated type OPLL.

Transcranial electrical stimulation motor evoked potentials (TcMEPs) became the gold standard for intraoperative spinal cord monitoring. However there is no definite alarm point of TcMEPs due to a lack of multicenter study. Thus we set 70% decrease of amplitude as the alarm point of TcMEPs from the experience of our 48 true positive cases from 2007 to 2009. 959 cases of spinal deformity, spinal cord tumor and ossification of the posterior longitudinal ligament (OPLL) were included in this prospective multicenter study from our 18 institutes related to the Japanese Society for Spine Surgery and Related Research monitoring working group from 2010 to 2012. There were only two false negative cases which were intramedullary spinal cord tumor. This new alarm criterion provided higher sensitivity (95%) and specificity (91.1%) for intraoperative spinal cord monitoring and good accuracy except for intramedullary spinal cord tumor. This study is the first prospective multicenter research to investigate the alarm point of TcMEPs. We recommend the alarm point to be a 70% decrease of amplitude for routine spinal cord monitoring, especially in surgery for spinal deformity, OPLL and extramedullary spinal cord tumor. [ABSTRACT FROM AUTHOR]

A response by Morii et al. to a letter the editor about their study on surgical site infection in malignant soft tissue tumors, which appeared in a 2011 issue is presented.