Objective Assessment of Sleep Disorders in Patients with Lumbar Spinal Stenosis Using Wearable Trackers.

Introduction: Low-back pain causes sleep disorders, which impairs the quality of life (QOL) of patients. Sleep disorders are associated with lumbar spinal stenosis (LSS); however, the postoperative effects of LSS surgery on sleep disorders are unknown. This study aimed to assess sleep disorders in patients with LSS using wearable activity trackers and determine whether surgery improves sleep quality. Methods: A total of 39 patients scheduled for LSS surgery (mean age 71.1±8.7 years; 22 men and 17 women) were studied. Sleep disorders in the participants were objectively evaluated using a wearable Motionlogger Micro system. Sleep efficiency (SEf), mean active count (MAC), and wake after sleep onset (WASO) were measured before and 6 months following surgery. Furthermore, the patient-based outcomes of pain and QOL-related scores were measured and compared with those of healthy participants. The group with improved SEf following surgery was designated as "nonpoor sleepers," whereas the group that did not exhibit improvements was designated as "poor sleepers." The two groups were compared based on patient factors, patient-based questionnaires, and sleep disorder measurements. Results: The SEf and WASO were significantly worse in patients with LSS compared with healthy participants (P<0.05). Furthermore, the SEf in patients with LSS was associated with the Oswestry Disability Index scores. No improvement was observed in the SEf, MAC, and WASO before and after surgery. Evaluation of each case revealed 21 and 12 cases of nonpoor and poor sleepers, respectively. Preoperative low-back pain was significantly associated with improvement in postoperative sleep quality. Conclusions: Sleep disorders in patients with LSS were evaluated, and improvement in sleep disorders following surgery was associated with the intensity of preoperative low-back pain. Sleep disorders are associated with QOL disorders, suggesting that focusing on the treatment of sleep disorders is important in the management of patients with LSS.

Computed Tomographic Assessment of Age- and Gender-Specific Sagittal Lumbopelvic Alignment in a Japanese Population.

INTRODUCTION: Previous studies have reported differences in lumbopelvic alignment between standing and supine positions. Computed tomography (CT) images taken in the supine position are often used for clinical studies in addition to standing radiographs, although not frequently. Our study aims to clarify normative values of CT-evaluated lumbopelvic parameters and the characteristics of age- and gender-related lumbopelvic alignment in the supine position. METHODS: Patients undergoing CT scans of abdominal or lumbar regions for reasons other than low back disorders were included (n=581). Sagittal multiplanar reconstruction CT images were obtained, and lumbar lordosis (LL), L5-S1 angle, and sacral slope (SS) were measured. Mean values of the parameters in patients aged 59 years and under, 60-69, 70-79, and 80 and over, and in males and females, were calculated. Age- and gender-related differences in these parameters were statistically analyzed. RESULTS: Among the four age groups, patients 80 years and over showed significantly lower LL and SS than patients aged 70-79. Females 80 years and over showed significantly lower LL and SS than all other age groups, but those in males did not. The comparison between males and females showed no significant differences in LL and SS; however, the L5-S1 angle was significantly higher in males than in females. In patients 80 years and over, females showed significantly lower LL and SS than in males. CONCLUSIONS: This study provides normative CT-evaluated lumbopelvic parameters, such as LL, L5-S1 angle, and SS, which will be utilized for comparisons in future studies. The present study first revealed that pelvic retroversion and lumbar kyphosis occur in elderly females in the supine position, which raised a possibility that age-related decrease of LL and SS in females occurs at an older age in the supine position than in the standing position.

Radiological Assessment of Damage to the Iliopsoas Muscle by the Oblique Lateral Interbody Fusion Approach.

INTRODUCTION: There are several reports about invasive muscle injury during posterior spinal surgery. However, few reports have evaluated the association between the clinical symptoms and changes in the physical properties of the psoas major after oblique lateral interbody fusion (OLIF). Therefore, the current study aimed to investigate the relationship between the clinical symptoms and changes in the psoas major muscle before and after OLIF. METHODS: Twenty-seven patients who underwent single-level OLIF following the diagnosis of degenerative lumbar disease were included in the study. The cross-sectional areas (CSAs) of the psoas major on the approaching and contralateral sides were measured in the axial computed tomography view of the surgical intervertebral space preoperatively and postoperatively at 1 week and 3, 6, and 12 months. The preoperative and postoperative changes in the CSAs were compared. Muscle degeneration was evaluated using axial magnetic resonance images at the same level as that in the CSA evaluation preoperatively and at 12 months postoperatively. Additionally, the relationship between these parameters and postoperative lower limb symptoms was investigated. RESULTS: Significant swelling of the psoas major on the approach side was observed 1 week postoperatively (p < 0.05). No postoperative muscle degeneration was observed. Three cases of paresthesia in the front of the thigh were observed, but no association was found with changes in CSA in any of the cases. CONCLUSIONS: The OLIF approach caused swelling of the psoas major 1 week postoperatively with no more muscle degeneration in the mid-term. Although numbness of the lower limbs was found in some cases, no association was found with changes in CSA. Our study findings suggest that the OLIF approach causes temporary injury or swelling of the psoas major, but the long-term damage to the muscle is not significant.

Pilot study of oblique lumbar interbody fusion using mobile percutaneous pedicle screw and validation by a three-dimensional finite element assessment.

The purpose of this study was to try oblique lateral interbody fusion (OLIF) using percutaneous pedicle screws (PPS) with mobility. Twelve patients who underwent single-level OLIF were observed for at least one year. These included 6 patients with conventional PPS (rigid group), and 6 with movable PPS (semi-rigid group). Mobile PPS used cosmicMIA, which is a load sharing system. The anterior and posterior disc height, screw loosening and bone healing period, and implant failure were evaluated at final observation by CT. Moreover, the stress on the vertebral body-cage, on the vertebral body-screw/rod and on the bone around the screw was estimated using a three-dimensional finite element assessment in both groups. There was no significant difference in surgical time, amount of bleeding, JOA score, or low back pain VAS between groups. There were no differences between groups in anterior and posterior disc height, screw loosening, and implant failure at final observation. The bone healing period was significantly shorter in the semi-rigid screw group (18.3 months vs 4.8 months, p = 0.01). The finite element analysis showed that the lower stress on the rod/screw would contribute to fewer implant fractures and that lower stress on the bone around the screw would reduce screw loosening, and that higher compressive force on the cage would promotes bone healing. OLIF combined with a movable screw accelerated bone healing by nearly 75%. We conclude that mobile PPS in combination with OLIF promotes bone healing and can be a better vertebral fusion technique.

Functional Assessment of Lumbar Nerve Roots Using Coronal-plane Single-shot Turbo Spin-echo Diffusion Tensor Imaging.

We investigated the usefulness of diffusion tensor imaging using single-shot turbo spin-echo sequence (TSE-DTI) in detecting the responsible nerve root by multipoint measurements of fractional anisotropy (FA) values. Five patients with bilateral lumbar spinal stenosis showing unilateral neurological symptoms were examined using TSE-DTI. In the spinal canal, FA values in the symptomatic side were lower than those in the asymptomatic side. TSE-DTI using multipoint measurements of FA values can differentiate the responsible lumbar nerve root.

Assessment of Clinical Symptoms in Lumbar Foraminal Stenosis Using the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire.

OBJECTIVE: It is important to develop an easy means of diagnosing lumbar foraminal stenosis (LFS) in a general practice setting. We investigated the use of the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) to diagnose LFS in symptomatic patients. METHODS: Subjects included 13 cases (mean age, 72 years) with LFS, and 30 cases (mean age, 73 years) with lumbar spinal canal stenosis (LSCS) involving one intervertebral disc. The visual analogue scale score for low back pain and leg pain, the JOABPEQ were evaluated. RESULTS: Those with LFS had a significantly lower JOA score (p<0.001), while JOABPEQ scores (p<0.05) for lumbar dysfunction and social functioning impairment (p<0.01) were both significantly lower than the scores in LSCS. The following JOABPEQ questionnaire items (LFS vs. LSCS, p-value) for difficulties in: sleeping (53.8% vs. 16.6%, p<0.05), getting up from a chair (53.8% vs. 6.6%, p<0.001), turning over (76.9% vs. 40%, p<0.05), and putting on socks (76.9% vs. 26.6%, p<0.01) such as pain during rest, and signs of intermittent claudication more than 15 minutes (61.5% vs. 26.6%, p<0.05) were all significantly more common with LFS than LSCS. CONCLUSION: Results suggest that of the items in the JOABPEQ, if pain during rest or intermittent claudication is noted, LFS should be kept in mind as a cause during subsequent diagnosis and treatment. LFS may be easily diagnosed from LSCS using this established patient-based assessment method.

Health assessment questionnaire-disability index (HAQ-DI) score at the start of biological disease-modifying antirheumatic drug (bDMARD) therapy is associated with radiographic progression of large joint damage in patients with rheumatoid arthritis.

OBJECTIVES: Radiographic progression of damage (RPD) to large joints in patients with rheumatoid arthritis (RA) has not been fully studied. We previously demonstrated that Larsen grade of the large joints was associated with RPD of large joints in patients treated with biological disease-modifying anti-rheumatic drugs (bDMARDs); however, no factors associated with background characteristics of patients were identified. METHODS: A total of 400 large joints in the upper and lower extremities, including the shoulder, elbow, knee, and ankle, of 88 patients with RA treated with bDMARDs for 1-3 years were investigated. Radiographs of tender and/or swollen large joints were acquired at least twice during the study period (mean, 16.4 months), and the RPD was evaluated. RESULTS: A multivariate analysis revealed that health assessment questionnaire-disability index (HAQ-DI) score at the start of bDMARD treatment was associated with RPD. The cutoff value that discriminated progression from non-progression, determined by a receiver operating characteristic (ROC) curve, was 1.4375 (sensitivity: 0.778, specificity: 0.894). CONCLUSIONS: HAQ-DI score at the start of bDMARD treatment was associated with RPD to large joints during a therapeutic period of 1-3 years. Progressive damage is expected to increase when functional disability exceeds an HAQ-DI score of 1.5.

Assessment of pain behavior in a rat model of intervertebral disc injury using the CatWalk gait analysis system.

STUDY DESIGN: Pain behavior and immunohistological analysis in intervertebral disc (IVD) injury model. OBJECTIVE: To investigate pain behavior in a rat model of IVD injury using the CatWalk system. SUMMARY OF BACKGROUND DATA: There are few reports examining low back pain behavior in animal models. The CatWalk is a computer-assisted gait analysis system that provides an automated way to assess gait function and pain-related alterations of this behavior. METHODS: In the IVD injury group, L5-L6 IVDs were injured with a 24-gauge needle. Simultaneously, the neurotracer Fluoro-Gold (FG; Fluorochrome, Denver, CO) was injected into the L5-L6 IVDs. In the sham group, FG was injected into the L5-L6 IVDs only. Animals in the control group received no operation. One, 2, 3, and 4 weeks after surgery, the gait of rats in the 3 groups was investigated using the CatWalk system. One, 2, and 4 weeks after surgery, in IVD injury and sham groups, dorsal root ganglions from the L1 to L6 levels were resected. Dorsal root ganglions were immunostained for calcitonin gene-related peptide. RESULTS: In the IVD injury group, the mean stands of hind paws and the mean duty cycle of front paws at some time points were significantly higher than those in the sham group. Furthermore, the mean stride length of the front and hind paws and the mean swing speed of the front and hind paws at some time points were significantly shorter than those in the sham group. The proportion of calcitonin gene-related peptide-immunoreactive, FG-labeled neurons among all FG-labeled dorsal root ganglion neurons in the IVD injury group was significantly higher than the corresponding proportion in the sham group. CONCLUSION: These results suggest that IVD injury produced significant changes in rat gait, including longer stance phases and shorter strides. In the future, we may be able to apply the CatWalk system to the evaluation of behavior associated with pain in models of low back pain. LEVEL OF EVIDENCE: N/A.

Assessment of gait in a rat model of myofascial inflammation using the CatWalk system.

STUDY DESIGN: Gait analysis and immunohistological analysis in a rat model of myofascial inflammation in low back. OBJECTIVE: To investigate gait in a rat model of myofascial inflammation using the CatWalk gait analysis system. SUMMARY OF BACKGROUND DATA: There are few reports examining low back pain behavior in animal models. The CatWalk is a computer-assisted gait analysis system that provides an automated way to assess gait function and this behavior during pain. METHODS: In a myofascial inflammation group, 0.5 mL of 4% paraformaldehyde buffer and 0.5 mL of 5% Fluoro-Gold (FG) buffer were injected into bilateral multifidus muscles of rats. In a control group, FG buffer alone was injected. Five days after surgery, the gait of rats in both groups was investigated using the CatWalk system. In the present study a total of 36 gait parameters were quantified and used to judge pain-related behavior. Bilateral dorsal root ganglia (DRGs) from L1 to L6 levels were resected, and immunostained for calcitonin gene-related peptide (CGRP). RESULTS: In the myofascial inflammation group, the mean duty cycle (duration of paw contact divided by time between consecutive paw contacts) of each paws (front and hind) were significantly higher and mean stride length (the distance between successive placements of the same paw) of each paws were significantly shorter compared with the control group. Furthermore, mean minimum contact intensity of the complete paw and mean contact intensity of each paws in the myofascial inflammation group were significantly higher compared with the control group. The proportion of CGRP-immunoreactive FG-labeled neurons among all FG-labeled DRG neurons in the myofascial inflammation group was significantly higher than the proportion in the control group. CONCLUSION: These results suggest that myofascial inflammation in low back caused the changes to the rat's gait, including long stands, short stride, and strong paw contact.