Trajectory of instantaneous axis of rotation in fixed lumbar spine with instrumentation

Background

Several studies showed instantaneous axis of rotation (IAR) in the intact spine. However, there has been no report on the trajectory of the IAR of a damaged spine or that of a fixed spine with instrumentation. It is the aim of this study to investigate the trajectory of the IAR of the lumbar spine using the vertebra of deer.

Methods

Functional spinal units (L5–6) from five deer were evaluated with six-axis material testing machine. As specimen models, we prepared a normal model, a damaged model, and a pedicle screw (PS) model. We measured the IAR during bending in the coronal and sagittal planes and axial rotation. In the bending test, four directions were measured: anterior, posterior, right, and left. In the rotation test, two directions were measured: right and left.

Results

The IAR of the normal model during bending moved in the bending direction. The IAR of the damaged model during bending moved in the bending direction, but the magnitude of displacement was bigger compared to that of the normal model. In the PS model, the IAR during bending test hardly moved. During rotation test, the IAR of the normal model and PS model located in the spinal canal, but the IAR of the damaged model located in the posterior part of the vertebral body.

Conclusions

In this study, the IAR of damaged model was scattering and that of PS model was concentrating. This suggests that higher mechanical load applied to the dura tube and nerve roots in the damaged model and less mechanical load applied to that in the PS model.

Tumoral calcinosis in the cervical spine: a case report and review of the literature

Background

Tumoral calcinosis is rarely located in spine. A 55-year-old Japanese woman with cervical tumoral calcinosis is presented, along with a review of the literature relating to tumoral calcinosis in the spine. We discussed the etiology, diagnosis, and management of this condition.

Case presentation

We report a case of a patient with cervical tumoral calcinosis with end-stage renal disease. A computed tomography scan showed a lobulated, calcified mass around the right facet joint at the fourth-fifth cervical spine and calcifications were also observed in the right intervertebral foramens at fourth-fifth cervical spine and fifth-sixth cervical spine levels and the anterior wall of the spinal canal. By performing a cervical decompression and stabilization, the patient recovered from her neurological symptoms.

Conclusions

Although tumoral calcinosis is rarely located in the spine, it should be considered in the differential diagnosis of spinal lesions. If a calcified mass causes acute neurological symptoms, resection of the mass is still the most important treatment.

Characteristics of Patients with High Lie Scores in a Personality Test

BACKGROUND

It is reported that persons with high Lie score (L score) of a personality test are aggressively self-confident and are also related to depression or schizophrenia In this study, we examined the characteristics of patients with high L scores on the Maudsley Personality Inventory (MPI) and examined the significance of the L score.

MATERIALS AND METHODS

We collected the data of 10789 subjects and examined the relationship between L score or the number of characteristic biased persons and the parameters of age, sex, education level, occupation, and degree of pain. Furthermore, we examined the changes in extraversion-introversion (E score), neuroticism (N score), and L scores at approximately 1 year after surgery in 1711 patients who underwent surgery at our university hospital or affiliated hospitals.

RESULTS

L score was significantly higher among persons with a high degree of pain, and ratio of the characteristic biased persons in L score was significantly high among persons in their 40s to 60s, healthcare professionals and those with a high degree of pain. Moreover, L score scarcely changed between before and after surgery when compared with E score and N score.

CONCLUSION

L score is not greatly influenced by an individual's state of mind or situation at different times, and may indicate the personality traits proper to the person. It is shown that L score may indicate the personality trait characteristics of persons who want to make themselves look good in the eyes of other.

Verification of the sensitivity of functional scores for treatment results - Substantial clinical benefit thresholds for the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ)

BACKGROUND

Validity and reliability of the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) had already been verified as the patients' self-rating assessment of low back pain and lumbar spinal disease and, the present study demonstrated the responsiveness of this measure.

METHODS

192 subjects who were determined by medical instructors of the Japanese Society for Spine Surgery and Related Research were analyzed. They had completed a series of treatment and both surveys before and after the treatment. Authors investigated rates of concordance between assessment by physicians and subjective assessment by patients. The mean, standard deviation, minimum, 25th percentile, median, 75th percentile and maximum values for pre-treatment, post-treatment, and acquired points were calculated, and then, we also investigated the trend between subjective assessment by patients and mean acquired points for each JOABPEQ domain and substantial clinical benefit thresholds for the JOABPEQ.

RESULTS

Symptom changes as assessed by physicians did not coincide with those by patients, and acquired points in each JOABPEQ domain were significantly increased with improved self-rating by patients. In addition, patients who rated symptom changes as "slightly improved" showed a mean acquired points of ≥20, and those reporting "improved" showed a 25th percentile points of the acquired points of ≥20 approximately.

CONCLUSION

A significant correlation was noted between the self-rating of patients and acquired points JOABPEQ, suggesting that ≥20 acquired points can be interpreted as substantial clinical benefit thresholds for the JOABPEQ.

Biomechanical assessment of the effects of vertebral distraction-fusion techniques on the adjacent segment of canine cervical vertebrae

OBJECTIVE To assess effects of vertebral distraction-fusion techniques at a treated segment (C5-C6) and an adjacent segment (C4-C5) of canine cervical vertebrae. SAMPLE Cervical vertebrae harvested from cadavers of 10 skeletally mature Beagles. PROCEDURES Three models (intact, titanium plate, and polymethylmethacrylate [PM MA]) for stabilization of the caudal region of the cervical vertebrae (C4 through C7) were applied to the C5-C6 vertebral segment sequentially on the same specimens. Biomechanical assessments with flexion-extension, lateral bending, and axial rotational tests were conducted after each procedure. Range of motion (ROM) for a torque load applied with a 6-axis material tester was measured at C4-5 and C5-6 and calculated by use of a 3-D video measurement system. RESULTS In both the plate and PMMA models, ROM significantly increased at C4-5 and significantly decreased at C5-6, compared with results for the intact model. The ROM at C5-6 was significantly lower for the plate model versus the PMMA model in lateral bending and for the PMMA model versus the plate model in axial rotation. Conversely, ROM at C4-5 was significantly higher in axial rotation for the PMMA model versus the plate model. No significant differences were identified in flexion-extension between the PMMA and plate models at either site. CONCLUSIONS AND CLINICAL RELEVANCE Results of this study suggested that vertebral distraction and fusion of canine vertebrae can change the mechanical environment at, and may cause disorders in, the adjacent segment. Additionally, findings suggested that effects on the adjacent segment differed on the basis of the fusion method used.

The Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ): A validation of the reliability of the Thai version

BACKGROUND

The Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) was developed by the Japanese Orthopedic Association (JOA) for assessment of lower back pain and lumbar spinal disease. We aimed to translate the JOABPEQ into Thai and test its reliability and validity in the Thai context.

METHODS

The original JOABPEQ was translated into Thai in accordance with international recommendations. Then 180 lumbar spinal disease patients (mean age 58.58 ± 11.97, 68.3% female) were asked to complete the Thai version of the JOABPEQ twice at 2-week intervals. Test-retest reliability was analyzed using the intra-class correlation coefficient (ICC). Internal consistencies were analyzed using Cronbach's alpha, while the construct validity was compared with the Thai version of the modified SF-36, and tested using the Spearman's rank correlation coefficient.

RESULTS

The Thai JOABPEQ showed satisfactory test-retest reliability in all parameters (Intra-class Correlation Coefficient 0.761-0.862). The variables low back pain, walking ability, social life function, and mental health had satisfactory internal consistency (the respective Cronbach's α was 0.798, 0.721, 0.707, and 0.795). Only the lumbar function parameter showed moderate reliability (Cronbach's α = 0.654). All of the variables in the Thai JOABPEQ had a statistically positive correlation with the correspondent Thai SF-36 subscales (Spearman's rank correlation p value < 0.05).

CONCLUSION

The Thai version of JOABPEQ had satisfactory internal consistency, test-retest reliability, and construct validity; it can be used as a reliable tool for assessing quality of life for lumbar spinal disease patients in Thailand.

Relief of Lower Back and Leg Pain after Myelography

Introduction:

It is well-known that many patients will have adverse reactions such as headache and nausea after undergoing myelography, but we have often seen cases where symptoms such as lower back pain and leg pain were alleviated following myelography. To the best of our knowledge, such clinical cases of post-myelographic alleviation have not been reported.

Materials and Methods:

A total of 325 patients with a degenerative lumbar spinal disorder who underwent myelography were prospectively investigated at four hospitals from April 2012 to March 2014 to survey the post-myelographic alleviation of lower back and leg pain prospectively. The severities of lower back pain, leg pain and numbness of the lower extremities were evaluated and intermittent claudication distance was measured before myelography. The magnetic resonance imaging (MRI) findings and myelographic findings were also evaluated for the patients that their symptoms were improved.

Results:

Thirty-five of 325 cases (10.8%) of these patients had their symptoms alleviated after undergoing myelography; 26 cases of lower back pain, two cases of leg pain, two cases of numbness of the lower extremity, and five cases of intermittent claudication.

Conclusion:

In the patients of a degenerative lumbar spinal disorder, about 10% cases with lower back pain or intermittent claudication had post-myelographic alleviation. Intradural injection therapy might be a therapeutic method to alleviate these symptoms.

An Effective New Cryopreservation Procedure for Pancreatic Islets Using Hollow Fiber Vitrification

The present study aimed at establishing a new cryopreservation method for mouse pancreatic islets by vitrification using hollow fibers as a container. A unique feature of the hollow fiber vitrification (HFV) method is that this method achieves stable vitrification using a minimum volume of cryoprotectant (CPA) solution, thereby ensuring high viability of the islets. The cytotoxicity, optimum composition, and concentration of the CPAs for vitrifying islets were examined. The viability, functional-integrity of vitrified islets were evaluated in comparison with those vitrified by conventional methods. Insulin secretion was measured in vitro by a static incubation assay and the metabolic functions was tested after transplantation into Streptozotocin-induced diabetic mice. The combination of 15% dimethyl sulfoxide+15% ethylene glycol resulted in the best CPA solution for the HFV of islets. HFV showed the highest viability in comparison to 2 vitrification methods, open pulled straws and vitrification with EDT324 solution. The vitrified islets stably expressed β-cells markers NeuroD, Pancreatic and duodenal homeobox-1, and MafA. Transplantation of the vitrified islets achieved euglycemia of the host diabetic mice and response to an intraperitoneal glucose tolerance test to a similar extent as non-vitrified transplanted islets. The HFV method allows for efficient long-term cryopreservation of islets.

Biomechanical study of rotational micromovement of the pedicle screw

Background

In regard to the fixation using a pedicle screw (PS) and rod system, the mechanism from the onset of the clear zone up to the development of loosening of the pedicle screw is not completely clarified. The purpose of this study is to determine the cause of the pedicle screw loosening by performing a biomechanical study with three-dimensional movie analysis.

Methods

Ten PS fixation model of the lumbar spines (L3–4) of boar cadavers were used. The rotational angles of the L3 and L4 vertebral body and the screw at the time of applying a ±5 Nm load in the left anterior and right posterior flexion directions respectively were calculated based on those at the time of applying no load. The absolute value of the difference in the rotational angles between each vertebral body with left anterior flexion and right posterior flexion and the inserted screws was defined as rotational micromovement.

Results

In both the left anterior and right posterior flexion directions, there were significant differences (p < 0.05) in the rotational angles between the screw and the vertebral body for both the L3 and L4 vertebral bodies.

Conclusion

Our biomechanical results showed that rotational micromovement occurred between the PS and the vertebral body, and repeated rotational micromovement might cause loosening of the screw or pullout of PS fixation.

Validation of the reliability of the Thai version of the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ)

BACKGROUND

The Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ) was developed to resolve problems associated with the original evaluation of cervical myelopathic patients. The aim of this study was to translate the JOACMEQ into Thai as per international recommendations, and to test its reliability and validity in the Thai context

METHODS

The JOACMEQ was translated into Thai, using international guidelines. Cervical myelopathy patients (n = 70; 31 males) were asked to complete the Thai version JOACMEQ twice (4 weeks apart). Test-retest reliability was analyzed using the intra-class correlation coefficient (ICC). Internal consistencies were analyzed using Cronbach's alpha, while the construct validity was compared with the Thai version modified SF-36; using the Spearman's rank correlation coefficient.

RESULTS

The Thai JOACMEQ produced good reliability (i.e., the ICC was >0.9 in 2 parameters and >0.8 in one). Overall the Cronbach's α for the 24 questions showed very high internal consistency (Cronbach's α > 0.8) and almost all Cronbach's α showed satisfactory internal consistency except for bladder function. The Spearman's rank correlation for all the JOACMEQ parameters had a positive correlation with all Thai SF 36 subscales, especially the quality of life parameter, which showed a strong correlation with all SF-36 subscales.

CONCLUSION

The Thai version of the JOACMEQ had satisfactory internal consistency and test-retest reliability: it also had good construct validity. It can therefore be used as a reliable tool for assessing quality of life for cervical myelopathy patients in Thailand.

Psychological effects of meditation at a Buddhist monastery in Myanmar

BACKGROUND

Meditation is widely used as a therapeutic measure because it can effectively reduce stress, pain, and improve the mental health, but there are many unclear points about the psychological effects of meditation.

AIMS

The purpose of this study is to verify the psychological effects of meditation.

METHOD

The short version of Profile of Mood States (POMS-SF) and the Acceptance and Action Questionnaire-II (AAQ-II) were conducted to compare 97 Myanmar people practicing Vipassana contemplation training with 81 Myanmar nurses who did not have any experience with meditation.

RESULTS

The results of our study revealed that meditation mitigated depressive mood, anger, hostility, and fatigue and increased vigor. The enhancement of psychological flexibility occurred only after practicing meditation for more than a year.

CONCLUSIONS

It can be considered that meditation mitigates anger, hostility and fatigue and increases vigor at a relatively early stage after starting meditation practice, and if meditation practice is continued for more than a year, enhancement of psychological flexibility can also be expected.

A Case of Lumbosacral Arachnoiditis Ossificans

The patient was a 13-year-old boy who complained of pain in both buttocks. Plain and reconstructive computed tomography (CT) images showed an ossified lesion within the dura mater at the L5-S2 levels, and arachnoiditis ossificans in the lumbosacral area was suspected. In the operative findings obtained after cutting the dura, a bone fragment 4.5 × 0.5 × 0.5 cm in size was observed in the center of the strongly adhesive nerve bundle of the cauda equina, which was removed en bloc. The postoperative clinical course of the patient was excellent. The case, along with a review of literature is presented.

A biomechanical comparison between cortical bone trajectory fixation and pedicle screw fixation

PURPOSE

There have been several reports on the pullout strength of cortical bone trajectory (CBT) screws, but only one study has reviewed the stability of functional spine units using the CBT method. The purpose of this study was to compare vertebral stability after CBT fixation with that after pedicle screw (PS) fixation.

METHODS

In this study, 20 lumbar spine (L5-6) specimens were assigned to two groups: the CBT model group that underwent CBT screw fixation (n = 10) and the PS model group that underwent pedicle screw fixation (n = 10). Using a six-axis material testing machine, bend and rotation tests were conducted on each model. The angular displacement from the time of no load to the time of maximum torque was defined as range of motion (ROM), and then, the mean ROM in the bend and rotation tests and the mean rate of relative change of ROM in both the bend and rotation tests were compared between the CBT and PS groups.

RESULTS

There were no significant differences between the CBT and PS groups with regard to the mean ROMs and the mean rate of relative change of ROMs in both the bend and rotation tests.

CONCLUSION

Intervertebral stability after CBT fixation was similar to that after PS fixation.

Intraosseous lipoma of the third lumbar spine: a case report

Introduction

Intraosseous lipoma is a benign bone tumor, and the tumor occurs more frequently in the lower extremities. We present a very rare case of intraosseous lipoma occurring in the lumbar vertebral arch and spinous process.

Case presentation

A 54-year-old Japanese man presented with a three-month history of lumbar pain. Magnetic resonance imaging of the L3 vertebral arch and spinous process revealed high intensity on T1- and T2-weighted imaging, and it was suppressed on fat-suppression imaging and no enhancement showed on gadolinium contrast-enhanced imaging. Computed tomography imaging revealed an osteolytic change accompanied by marginal osteosclerosis in his third lumbar vertebral arch and spinous process, as well as a thinned and bulging bone cortex. An analgesic had been administered prior to his visit, but low back pain had persisted, so we performed curettage and filled the defect with hydroxyapatite bone. His low back pain was improved immediately after surgery, and no recurrence of tumor has been observed on computed tomography imaging as of three years postoperatively.

Conclusions

Symptomatic intraosseous lipoma of spine is very rare, but the patient may be surgically well-treated by curettage and reconstruction of the benign tumor.

Long-term result of posterolateral fusion of the lumbar spine using the Tadpole system

BACKGROUND

Failure of pedicle screw fixation is often seen in patients with severe osteoporosis. We developed new lumbar spinal instrumentation (Tadpole system) for elderly patients who have osteoporotic bone and poor general health status. The objective of this study was to document the long-term clinical outcomes after Tadpole system fixation, the rate of spinal fusion, the incidence of adjacent segment degeneration, the rate of instrumentation failure, and the overall complications.

METHODS

Sixty patients who underwent posterolateral spinal fusion using the Tadpole system, in whom a radiograph of the lumbar spine was taken at more than 5 years after operation, were involved in this study. The improvement rate of the Japanese Orthopaedic Association (JOA) score, rate of spinal fusion, presence or absence of adjacent segment degeneration, rate of instrumentation failure, and postoperative complications of each patient were assessed at 5 years postoperatively.

RESULTS

The mean JOA score improvement was 72.5%, and the posterolateral spinal fusion rate was 93.3% (56 of 60 patients) at the last follow-up. Adjacent segment degeneration occurred in only two patients who showed decreased intervertebral disc height, and instrumentation failure (hook deviation) was observed in one patient. No other complications were observed in any patients.

CONCLUSION

Tadpole system fixation shows favorable long-term clinical outcomes.

An outcome measure for patients with cervical myelopathy: the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ): an average score of healthy volunteers

BACKGROUND

An outcome measure to evaluate the neurological function of patients with cervical myelopathy was proposed by the Japanese Orthopaedic Association (JOA score) and has been widely used in Japan. However, the JOA score does not include patients' satisfaction, disability, handicaps, or general health, which can be affected by cervical myelopathy. In 2007, a new outcome measure, the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), which is a self-administered questionnaire, was developed. However, the influence of age and gender on the scores has not been fully examined. The purpose of this study was to establish the standard value of the JOACMEQ by age using healthy volunteers.

METHODS

This study was conducted in 23 university hospitals and their affiliated hospitals from September to December 2011. The questionnaire included 24 questions for evaluation of physical function of the cervical spine and spinal cord. A total of 1,629 healthy volunteers were recruited for the study. The ages ranged from 20 to 89 years old.

RESULTS

The volunteers comprised 798 men and 831 women. In the elderly healthy volunteers, the JOACMEQ scores decreased with age. In general, the scores for cervical spine function and upper/lower extremity function were retained up to the 60s, then decreased in the 70s and 80s. The scores for quality of life were retained up to the 70s; however, the score for bladder function was retained up to the 40s, then declined with age from the 50s to 80s.

CONCLUSION

The standard values of the JOACMEQ by age were established. Differences in the scores were found among different generations. Patients with cervical myelopathy should be evaluated with this new self-administered questionnaire taking into account the standard values according to different ages.

Prediction of the remnant liver hypertrophy ratio after preoperative portal vein embolization

BACKGROUND

Portal vein embolization (PVE) is considered to improve the safety of major hepatectomy. Various conditions might affect remnant liver hypertrophy after PVE. The aim of the present study was to clarify the factors that affect remnant liver hypertrophy and to establish a prediction formula for the hypertrophy ratio.

METHODS

Fifty-nine patients who underwent preoperative PVE for cholangiocarcinoma (39 patients), metastatic carcinoma (10 patients), hepatocellular carcinoma (8 patients), and other diseases (2 patients) were enrolled in this study. For the prediction of the hypertrophy ratio, a formula with stepwise multiple regression analysis was set up. The following parameters were used: age, gender, future liver remnant ratio to total liver (FLR%), plasma disappearance rate of indocyanine green (ICGK), platelet count, prothrombin activity, serum albumin, serum total bilirubin at the time of PVE and the maximum value before PVE (Max Bil), as well as a history of cholangitis, diabetes mellitus, and chemotherapy.

RESULTS

The mean hypertrophy ratio was 28.8%. The 5 parameters detected as predictive factors were age (p = 0.015), FLR% (p < 0.001), ICGK (p = 0.112), Max Bil (p < 0.001), and history of chemotherapy (p = 0.007). The following prediction formula was established: 101.6 - 0.78 × age - 0.88 × FLR% + 128 × ICGK - 1.48 × Max Bil (mg/dl) - 21.2 × chemotherapy. The value obtained using this formula significantly correlated with the actual value (r = 0.72, p < 0.001). A 10-fold cross validation also showed significant correlation (r = 0.62, p < 0.001), and a hypertrophy ratio <20% was predictable with a sensitivity of 100% and a specificity of 90.9%. Moreover, technetium-99m-diethylenetriaminepentaacetic acid-galactosyl human serum albumin scintigraphy showed a significantly smaller increase in the uptake ratio of the remnant liver in patients with prediction values <20% than in those with values ≥20% (6.8 vs. 20.8%, p = 0.030).

CONCLUSIONS

The prediction formula can prognosticate the hypertrophy ratio after PVE, which may provide a new therapeutic strategy for major hepatectomy.