Gender differences in the prevalence of low back pain associated with sports activities in children and adolescents: a six-year annual survey of a birth cohort in Niigata City, Japan.

BACKGROUND: This study was conducted to determine gender differences in the relationship between extracurricular sports activities (ECSA) and low back pain (LBP) in children and adolescents. METHODS: In a cohort analysis of a 6-year birth cohort annual survey, students were followed from the fourth to sixth grades of elementary school (E4-E6; 9-12 years old) through the first to third grades of junior high school (J1-J3; 12-15 years old). All students completed annual questionnaires on ECSA and LBP. The odds ratio (OR) and 95% confidence interval (CI) were calculated to assess the association strength between ECSA and LBP. We also calculated the population attributable fraction (PAF), which was defined as the proportion of students with ECSA-related LBP among all students with LBP. RESULTS: ECSA was significantly associated with LBP only in grade J3 among boys (OR: 2.00, 95% CI: 1.47-2.71). On the other hand, among girls, ECSA was significantly associated with LBP in grades E5 (OR: 1.48, 95% CI: 1.00-2.20), E6 (OR: 1.91, 95% CI: 1.33-2.75), and J3 (OR: 1.81, 95% CI: 1.26-2.61). Among boys, PAF was similar in all grades (range, 10-16%), whereas among girls, the PAF varied (- 11 to 29%) and was significantly higher in girls than in boys in grades E5 (19.0% vs. 1.1%, P < 0.01) and E6 (28.8% vs. 12.8%, P < 0.01). CONCLUSIONS: Although there was a link between ECSA and LBP in both boys and girls, girls were more susceptible to ECSA-related LBP, especially in grades E5 and E6.

Surgical treatment for osteoporotic thoracolumbar vertebral collapse using vertebroplasty with posterior spinal fusion: a prospective multicenter study.

PURPOSE: The study aimed to investigate the clinical outcomes and limitations after vertebroplasty with posterior spinal fusion (VP+PSF) without neural decompression for osteoporotic vertebral collapse. METHODS: We conducted a prospective multicenter study including 45 patients (12 men and 33 women, mean age: 77.0 years) evaluated between 2008 and 2012. Operation time, blood loss, visual analog scale (VAS) of back pain, neurological status, kyphosis angle in the fused area, and vertebral union of the collapsed vertebra were evaluated. RESULTS: The mean operation time was 162 min and blood loss was 381 mL. The postoperative VAS score significantly improved, and the neurological status improved in 35 patients (83 %), and none of the remaining patients demonstrated a deteriorating neurological status at two years post-operatively. The mean kyphosis angle pre-operatively, immediately post-operatively, and two years post-operatively was 23.8°, 10.7°, and 24.3°, respectively, and there was no significant difference between the angles pre-operatively and two years post-operatively. The extensive correction of kyphosis >16° was a risk factor for a higher correction loss and subsequent fracture. Union of the collapsed vertebra was observed in 43 patients (95 %) at two years post-operatively. CONCLUSIONS: The present study suggests that spinal stabilization rather than neural decompression is essential to treat OVC. Short-segment VP+PSF can achieve a high union rate of collapsed vertebra and provide a significant improvement in back pain or neurological status with less invasive surgery, but has a limit of kyphosis correction more than 16°.

Body mass index is associated with low back pain in childhood and adolescence: a birth cohort study with a 6-year follow-up in Niigata City, Japan.

PURPOSE: To investigate the successive change of low back pain (LBP) prevalence in childhood and adolescence and to examine the associations between LBP and extracurricular sports activities (ECSA) or body mass index (BMI) using a 6-year birth cohort study. METHODS: LBP reports of a grade (4,597 pupils at the beginning) were tracked over 6 years (between the ages of 9 and 14 years old), and anonymous questionnaires were distributed to them yearly. After grading the severity of the LBP into three levels and noting the transitions of the point and the lifetime prevalence of LBP, associations between point prevalence of LBP and BMI or ECSA were evaluated. RESULTS: The point prevalence of LBP had a tendency to become significantly higher as the pupils got older until they became 13 years old. The lifetime prevalence of LBP significantly increased as they got older yearly. As for the severity of LBP among students with a lifetime prevalence, the rate of more severe LBP (levels 2 and 3) increased as they got older. Significant positive associations were recognized between BMI and point prevalence of LBP in every years old (p < 0.05) and between ECSA and point prevalence of LBP at 11 (p = 0.001) and 14 years old (p < 0.001). CONCLUSIONS: The point and lifetime prevalence of LBP and the rate of more severe LBP increased as the pupils got older. BMI may be associated with LBP in childhood and adolescence.

Three-dimensional evaluation of volume change in ossification of the posterior longitudinal ligament of the cervical spine using computed tomography.

BACKGROUND: Two-dimensional imaging is not adequate for evaluating ossification of the posterior longitudinal ligament (OPLL). This study was designed to evaluate the accuracy of a novel computed tomography (CT)-based three-dimensional (3D) analysis method that we had devised to measure volume changes in OPLL. SUBJECTS AND METHODS: Twenty OPLL patients (12 male and 8 female; mean age 63.6 years) who were being followed conservatively were examined twice with an interval of at least 1 year between the two scans. The mean interval was 22 (range 12-45) months. A 3D model was created with DICOM data from CT images, using the MIMICS(®) software to calculate the volume. The mean ossification volume was determined from two measurements. Since ossification size varies widely, evaluation of change in volume is generally affected by the original size. Therefore, the change in ossification volume between the first and second CT examinations was calculated as the annual rate of progression. RESULTS: The type of OPLL was classified as continuous in 3 patients, segmented in 3, and mixed in 14. The mean ossification volume was 1,831.68 mm(3) at the first examination and 1,928.31 mm(3) at the second, showing a significant mean increase in ossification volume. The mean annual rate of lesion increase was 3.33% (range 0.08-7.79%). CONCLUSION: The 3D method used allowed detailed OPLL classification and quantification of change in the ossified volume. Thus, this method appears to be very useful for quantitative evaluation of OPLL with only minimal measurement error.

Atypical findings on magnetic resonance imaging in the patients with active pyogenic spondylitis in Japanese university hospitals.

Recently, aging population and immuno-compromised patients have been rising in Japan. Accordingly, patients with pyogenic spondylitis have been increasing and may present atypical clinical features. University hospitals treat many elderly patients and patients with poor general condition. Therefore, patients with pyogenic spondylitis treated at two university hospitals were retrospectively investigated to clarify the recent clinical and radiologic characteristics of this infection. There were 30 patients (average age: 68 years) treated in two university hospitals between 2009 and 2010. The onset was acute or subacute in 15 patients, insidious in 7 and unclassified in 8. Culture tests were performed in 25 patients, and the causative microorganisms were identified in 20 patients with the identification rate of 80%, including 4 patients infected by methicillin-resistant staphylococci. Classically, active pyogenic spondylitis is characterized by typical findings on magnetic resonance imaging (MRI): obvious signal decrease in T1-weighted image (WI) and increase in T2WI with contrast enhancement found in most of the bodies of two adjacent vertebrae and the intervening intervertebral disc. Among 29 patients with active pyogenic spondylitis, whose lesions were not in the healing stage, 16 patients demonstrated at least one of the atypical MRI findings; 9 patients showed involvement ≥ 3 vertebrae or only 1 vertebra, 5 showed the signal changes of the lesions involving small, spotty, or faint areas, and 3 showed small vertebral lesions but larger epidural or paraspinal abscesses. In conclusion, currently, about half of the patients with pyogenic spondylitis demonstrate atypical MRI findings in the university hospitals in Japan.

Clinical outcomes of posterior lumbar interbody fusion for lumbar foraminal stenosis: preoperative diagnosis and surgical strategy.

STUDY DESIGN: A retrospective case study of the use of posterior lumbar interbody fusion (PLIF) to treat lumbar foraminal stenosis (LFS). OBJECTIVES: To characterize the features of clinical symptoms, radiographic evaluation, and surgical outcomes of PLIF in LFS. SUMMARY OF BACKGROUND DATA: There is no gold standard for the surgical treatment of foraminal stenosis, which occurs in 8% to 10% of surgical cases of lumbar degenerative disease. METHODS: Data from 31 patients (33 segments) who underwent PLIF from 2001 to 2005 at our institution were analyzed. Exclusion criteria included the patients having both LFS and central canal stenosis, plus extraforaminal or intraforaminal disc herniation. There were 22 males and 9 females, with an average age of 61 (31~78 y). The affected levels were as follows: L3/4 in 1 patient, L4/5 in 4, and L5/S1 in 28. All patients underwent PLIF with the combination of segmental pedicle screws, interbody cages, and autogenous local bone graft. RESULTS: The frequencies of Kemp sign (+), intermittent claudication, leg pain in a sitting position, and leg pain at night, were high. Radiographic evaluation showed severe disc degeneration such as loss of disc height, massive osteophyte formation, and transverse offset angles of the nerve root at the corresponding level. Magnetic resonance imaging and 3D-reconstraction computed tomography clearly showed intraforaminal stenosis in sagittal, axial, and coronal planes. The PLIF procedure provided complete root decompression, restoration of disc height, and preservation of lumbar lordosis at final follow-up. The Japanese Orthopedic Association score improved from 17.1 points preoperatively to 24.9 points at final follow-up, and the overall fusion rate was 100%. CONCLUSION: Lumbar foraminal stenosis could be reliably diagnosed by distinctive clinical symptoms, and various radiographic examinations such as plain x-ray, Magnetic resonance imaging, and 3D-reconstraction computed tomography. The PLIF procedure, in combination with segmental pedicle screws, interbody cages, and autogenous local bone graft provides excellent clinical outcomes, and is a rational and useful surgical option for lumbar foraminal stenosis.

Investigating the minimum distance between the finger flexor tendons and distal radius during wrist and finger positions in healthy people.

PURPOSE: Rupture of the flexor pollicis longus (FPL) and index flexor digitorum profundus (FDP2) tendons often occurs after locking plate fixation for distal radius fracture. This study aimed to determine the shortest tendon-radius distances of different hand positions. METHODS: Fifty-nine hands of 30 healthy volunteers were studied. Distances between the FPL or FDP2 and distal radius were calculated in six wrist positions: 30° palmar flexion, neutral, 30° dorsiflexion, 60° dorsiflexion, maximum dorsiflexion, and 40° ulnar deviation with three finger positions (full extension and flexion of fingers, full flexion of the thumb or index finger, and full extension of the other four fingers). The shortest distance between the FPL or FDP2 and distal radius was noted. RESULTS: The shortest distance between the FPL and distal radius was during maximum wrist dorsiflexion with isolated thumb flexion. The distance between the FDP2 and distal radius was shortest with all-finger flexion in 30° wrist dorsiflexion. CONCLUSIONS: It is necessary to measure the distance between the FPL and distal radius in maximal wrist dorsiflexion with full flexion of the isolated thumb, as the shortest distance was observed with flexion of the isolated thumb. On the contrary, we recommend measuring the distance between the FDP2 and distal radius in 30° wrist dorsiflexion with flexion of all fingers.

Preoperative evaluation of the vertebral arteries and posterior portion of the circle of Willis for cervical spine surgery using 3-dimensional computed tomography angiography.

STUDY DESIGN: A retrospective analysis using prospectively collected data from 3-dimensional computed tomography angiography (3D-CTA). OBJECTIVE: To investigate the frequency of anomalous vertebral arteries (VA) and variations of the posterior portion of the circle of Willis (PPCW) using 3D-CTA for preventing perioperative iatrogenic vascular complications. SUMMARY OF BACKGROUND DATA: Some studies have reported that preoperative 3D-CTA is useful for determining the VA blood flow in the cervical spine. However, preoperative 3D-CTA has not been used for evaluating PPCW, which functions as vessels collateral to the basilar artery in the case of iatrogenic VA injury. METHODS: The study included 100 consecutive patients (61 males and 39 females; mean age, 60.4 ± 15.4 yr; range, 11-86 yr) who underwent cervical decompression and/or instrumentation between April 2008 and May 2012. We measured the diameters of the VA (VAD), posterior communicating artery (PCOMD), first segment of the posterior cerebral artery (P1D), and basilar artery (BAD) twice and determined the frequency of anomalous VA and PPCW variations. RESULTS: Hypoplastic VA, hypoplastic PCOM, and hypoplastic P1 were detected in 11 (11.0%), 81 (81.0%), and 13 patients (13.0%), respectively. Hypoplastic PCOM-P1 and hypoplastic basilar artery were observed in 87 (87.0%) and 3 patients (3.0%), respectively. Overall, 47 patients (47.0%) possessed some degree of abnormal VA blood flow.There were 7 patients (7.0%) with both unilaterally hypoplastic VA and bilaterally hypoplastic PCOM-P1s, in whom iatrogenic VA injury on the dominant side could have caused lethal vascular complications. We termed the hypoplastic VA of the contralateral side without collateral vessels as "critical VA." CONCLUSION: The VAs and PPCW vary considerably. Preoperative 3D-CTA provides important information for preventing tragic vascular complications caused by iatrogenic VA injury. Taking the risk of radiation into consideration, we recommend this method for patients at the highest risk for iatrogenic VA injury.

Descending aortic injury by a thoracic pedicle screw during posterior reconstructive surgery: a case report.

STUDY DESIGN: Case report. OBJECTIVE: To describe an iatrogenic aortic injury by pedicle screw instrumentation during posterior reconstructive surgery of spinal deformity. SUMMARY OF BACKGROUND DATA: Iatrogenic major vascular injuries during anterior instrumentation procedures have been reported by several authors, but there have been few reports regarding iatrogenic major vascular injuries during posterior instrumentation procedures. METHODS: A 57-year-old woman with thoracolumbar kyphosis due to osteoporotic T12 vertebral fracture underwent posterior correction and fusion (T10-L2), using segmental pedicle screw construct concomitant with T12 pedicle subtraction osteotomy. Postoperative routine plain radiographs and computed tomography myelography demonstrated a misplaced left T10 pedicle screw, which was in contact with the posteromedial aspect of the thoracic aorta, and suspected penetration of the aortic wall. The patient underwent removal of the pedicle screw, and repair of the penetrated aortic wall through a simultaneous anterior-posterior approach. RESULT: The patient tolerated the procedure well without neurologic sequelae, and was discharged several days after removal of a left tube thoracostomy. Plain radiographs demonstrated solid fusion at the osteotomy site and no loosening of hardware. Preoperative neurologic symptoms improved completely at 18-months follow-up. CONCLUSION: Use of pedicle screw instrumentation has the potential to cause major vascular injury during posterior spinal surgery, and measures to prevent this complication must be taken. Timely diagnosis and treatment are essential to prevent both early and delayed complications and death.