Balancing ability of patients with lumbar spinal canal stenosis.

PURPOSE: To determine the relationship between postural sway and the severity of lumbar spinal canal stenosis as well as the effect on postoperative improvement. METHODS: Stabilometry was performed before and 6 months after surgery in 52 patients (29 men and 23 women; mean age, 74.1 ± 7.8 years) who underwent decompression surgery for lumbar spinal canal stenosis. The environmental area (EA; the area surrounding the circumference of the stabilogram) and locus length per EA (L/EA) were evaluated. The patients were divided into moderate (n = 22) and severe (n = 30) groups according to the severity of canal stenosis. Patient characteristics and parameters were compared between the groups before and after surgery, including the visual analog scale (VAS) score for leg pain, Oswestry Disability Index (ODI), EA, and L/EA. In addition, factors affecting EA and L/EA were evaluated using multiple regression analysis. RESULTS: Age (p = 0.031), preoperative EA (p < 0.001), preoperative L/EA (p = 0.032), and sagittal vertical axis (p = 0.033) were significantly different between groups. The VAS score and ODI significantly improved postoperatively in both groups (p < 0.001). The EA significantly improved postoperatively only in the severe group (p < 0.001), whereas the L/EA did not significantly improve in either group. Multiple regression analysis showed that only the severity of canal stenosis was significantly associated with preoperative EA (p = 0.030), whereas age (p = 0.040) and severity of canal stenosis (p = 0.030) were significantly associated with preoperative L/EA. Diabetes was significantly associated with postoperative EA (p = 0.046) and L/EA (p = 0.030). CONCLUSION: The severity of canal stenosis affected abnormal postural sway, which improved after decompression surgery.

Percutaneous Intervertebral-Vacuum Polymethylmethacrylate Injection for Foraminal Stenosis with Degenerative Lumbar Scoliosis.

BACKGROUND: Percutaneous intervertebral-vacuum polymethylmethacrylate injection (PIPI) is a minimally invasive procedure for low back pain in elderly patients with degenerative lumbar scoliosis (DLS). Patients with DLS often have radiculopathy as a result of foraminal stenosis in addition to low back pain. The purpose of this study was to evaluate the clinical and radiologic results of PIPI for foraminal stenosis with radiculopathy in elderly patients with DLS. METHODS: We included patients with de novo DLS aged 65 years or older who underwent PIPI. The presence of an intervertebral vacuum on computed tomography and bone marrow edema on magnetic resonance imaging was required for inclusion. The intersegmental radiologic parameters on plain radiographs and computed tomography and the extent of bone marrow edema on magnetic resonance imaging were measured. The clinical outcomes were evaluated using the visual analog scale (VAS) and Oswestry Disability Index (ODI). RESULTS: We enrolled 40 patients with DLS who underwent PIPI. There were 16 men and 24 women, and the mean age was 79.0 ± 6.3 years. The mean foraminal height and extent of bone marrow edema showed a significant increase and reduction, respectively, after PIPI (P < 0.05). VAS score for radiculopathy and ODI significantly improved after PIPI (P < 0.01). The minimum clinically important differences in VAS score for radiculopathy and ODI at the final follow-up were 73.9% and 63.6%, respectively. CONCLUSIONS: PIPI is a minimally invasive procedure not only for low back pain but also for radiculopathy in elderly patients with DLS. It leads to intervertebral stabilization and indirect decompression of the foramen.

Spinous Process Fractures in Osteoporotic Vertebral Fractures: A Cross-Sectional Study.

Introduction: The purpose of this study was to assess radiological features and clinical scores of osteoporotic vertebral fracture (OVF) accompanied by spinous process fracture (SPF). Methods: We included painful patients with single-level OVF with intravertebral cleft. SPF was detected using magnetic resonance imaging (MRI) and/or computed tomography (CT). The plain radiographs of the vertebral fractures were evaluated based on the wedging angle of the fractured vertebrae and vertebral instability. We investigated the clinical parameters of age, gender, visual analog scale (VAS) score for low back pain (LBP), Oswestry Disability Index (ODI), and the period from the onset of acute fracture. Results: MRI and/or CT indicated among 195 patients of OVF with LBP, 41 patients (20.5%) had SPFs. SPFs were observed one level above the fractured vertebral body in 35 patients (85.4%) and at the same level as the fractured vertebral body in 6 patients (14.6%). The prevalence of vertebral fracture of thoracic spine in the SPF-positive group was significantly greater than that in the SPF-negative group. There were no significant differences in age, gender, VAS, ODI, the time period from the onset of acute LBP, wedging angle, and vertebral instability between the presence or absence of SPFs. Conclusions: SPFs occurred in 20.5% of patients with OVF and LBP. In addition, SPFs often occurred one level above the fractured vertebra, and SPFs with OVF tended to be located in the thoracic spine.

Long-term outcome of targeted therapy for low back pain in elderly degenerative lumbar scoliosis.

PURPOSE: Treatment of low back pain (LBP) associated with elderly degenerative lumbar scoliosis (DLS) remains controversial. We have developed percutaneous intervertebral-vacuum polymethylmethacrylate injection (PIPI) targeting to the intervertebral vacuum as a minimally invasive surgery. The present study compared the long-term clinical outcomes of PIPI to that of nonoperative treatment. METHODS: Patients with de novo DLS, aged ≥ 65 years, who had LBP with visual analog scale (VAS) of ≥ 50 for ≥ 6 months with intervertebral vacuum on computed tomography and bone marrow edema (BME) on magnetic resonance imaging were included. The clinical outcomes were evaluated using VAS and the Oswestry Disability Index (ODI) at baseline, 1, 6, 12, 24 months, and at the final follow-up. The course of BME was also evaluated. RESULTS: One hundred and one patients underwent PIPI and 61 received nonoperative treatment. The mean follow-up duration after PIPI and nonoperative treatment was 63.7 ± 32.4 and 43.9 ± 20.9 months, respectively. VAS and ODI after PIPI were significantly improved compared to post-nonoperative treatment. BME decreased substantially in the PIPI group and it was significantly correlated with VAS and ODI improvement. Following PIPI, LBP recurred in 28 patients (35%). LBP recurrence was identified at the same level of PIPI in 10 patients, at the adjacent level of PIPI in 11 patients, and at the non-adjacent level of PIPI in seven patients. Eighteen patients underwent additional PIPIs, and both VAS and ODI were significantly improved after additional PIPIs. CONCLUSION: Bone marrow lesions of the endplate are strongly associated with the presence of LBP. PIPI can be considered as an effective, safe and repeatable treatment for LBP in elderly DLS patients.

Lateral wall fixation with bone pegs for advanced osteochondritis dissecans of the humeral capitellum.

BACKGROUND AND HYPOTHESIS: It is generally considered that fragment fixation with bone pegs (FFBP) for osteochondritis dissecans (OCD) of the humeral capitellum can be indicated for stages I and II according to the International Cartilage Repair Society (ICRS) classification of OCD and it is difficult to obtain complete bone union for advanced lesions. However, the clinical and radiologic results of FFBP with cancellous bone graft for ICRS-OCD stage III with lateral wall involvement have not been described in detail. Good bone union can be achieved with the lateral wall fragment of the capitellum by FFBP in combination with refreshing the sclerotic surface at the base of the lesion and cancellous bone grafting even in ICRS-OCD stage III lesions. METHODS: In total, 10 adolescent baseball players with a diagnosis of OCD, a median age of 13.5 years at the time of surgery, and 26.7 months of postoperative follow-up were included. Preoperative imaging showed that all patients had lesions in the late detached stage and of the lateral-widespread type based on the site of the focal lesion. The intraoperative ICRS-OCD classification was stage III. We aimed to preserve and fix the lateral wall fragment with cancellous bone grafting if the condition of the articular cartilage was good and the size and thickness of the segment could withstand fixation. RESULTS: Bone union of the lateral wall fragment was achieved in all cases. The elbow extension range of motion was -3.9° ± 9.7° before surgery and was eventually -0.4° ± 6.7° at the final assessment. Flexion range of motion ranged from 138.1° ± 10.5° to 142.4° ± 6.2°. The Timmerman and Andrews score significantly improved from 165.5 ± 10.9 points before surgery to 197.0 ± 6.3 points after surgery, demonstrating excellent results in all patients. All patients were able to return to competitive baseball. CONCLUSION: The radiographic and clinical outcomes of FFBP for lateral wall fragments with cancellous bone graft were satisfactory, showing that the indications for this procedure could be extended to ICRS-OCD stage III.

Structural Analysis of Experimentally Induced Disc Herniation-Like Changes in the Rat.

INTRODUCTION: A disc herniation has traditionally been considered as disc tissue that has slipped out from an intervertebral disc. However, it was recently suggested that the disc herniation mass is a product of bioactive substances from the disc and that the disc hernia would more likely be scar tissue than herniated disc material. In this study, we aimed to analyze the structural components of experimentally induced disc herniations and compare with scar tissue and nucleus pulposus, in the rat. METHODS: Twenty-eight rats had their L4-5 discs punctured. After three weeks, the nodule that had been formed over the puncture site, scar tissue from the spine musculature, and normal nucleus pulposus were harvested and processed for further analysis. RESULTS: Proteomics analysis demonstrated that the formed nodule was more similar to scar tissue than to nucleus pulposus. Gene expression analysis showed that there was no resemblance between any tissues when looking at inflammatory genes but that, there was a clear resemblance between the nodule and scar tissue when analyzing extracellular matrix-related genes. Analysis of the GAG and polysaccharide size distribution revealed that only the nodule and scar tissue contained the shorter versions, potentially short chain hyaluronic acid that is known to induce inflammatory responses. The hematoxylin and eosin stained sections of the nodule, disc tissue, and scar tissue indicated that the morphology of the nodule and scar tissue was very similar. CONCLUSIONS: The nodule formed after experimental disc puncture, and that resembles a disc hernia, has a more structural resemblance to scar tissue than disc tissue. The nodule is, therefore, more likely to be induced by disc-derived bioactive substances than being formed by herniated disc material.

Electrophysiological assessments of the motor pathway in diabetic patients with compressive cervical myelopathy.

OBJECT: The occurrence of compressive cervical myelopathy (CCM) increases in adults over 50 years of age. In addition, diabetes mellitus (DM) is a frequent comorbidity for people of this age and may impact the severity of CCM. The authors assessed motor pathway function in diabetic patients with CCM to investigate the correlation between electrophysiological parameters and clinical symptoms. METHODS: Motor evoked potentials (MEPs) were measured from the abductor digiti minimi muscle (ADM) and the abductor hallucis muscle (AH) following transcranial magnetic stimulation, as were M- and F-waves following electrical stimulation of the ulnar and tibial nerves, in 22 patients with CCM and diabetes mellitus (DM) who had not experienced symptomatic diabetic neuropathy (CCM-DM group), in 92 patients with CCM alone (CCM group), and in 24 healthy adults (control group). The peripheral conduction time (PCT; measured from the ADM and AH) was calculated as follows: (M-wave latency + F-wave latency -1)/2. The central motor conduction time (CMCT; measured from the ADM and AH) was calculated by subtracting the PCT from the onset latency of the MEPs. The Japanese Orthopaedic Association (JOA) score for cervical myelopathy was obtained before and 1 year after surgery as a clinical outcome measure. RESULTS: MEP, PCT, and CMCT parameters in the CCM-DM and CCM groups were significantly longer than those in the control group (p = 0.000-0.007). The PCTs in the CCM-DM group were significantly longer than those in the CCM group (p = 0.001-0.003). No significant differences were detected in the MEP and CMCT parameters between the CCM-DM and CCM groups (p = 0.080-1.000). The JOA score before surgery in the CCM-DM group was 10.7 ± 2.0 points and was significantly lower than that in the CCM group (12.2 ± 2.5 points, p = 0.015). In the CCM-DM group, JOA scores before surgery correlated with MEP-AH (r = -0.610, p = 0.012) and PCT-AH (r = -0.676, p = 0.004) values, but not with CMCT values, while the JOA scores were related to both MEP and CMCT parameters in the CCM group. The JOA scores improved to 13.8 ± 2.2 points after surgery (p = 0.001) and correlated with MEP-AH (r = -0.667, p = 0.005) and PCT-AH (r = -0.611, p = 0.012) in the CCM-DM group. CONCLUSIONS: The results suggest that MEP, PCT, and CMCT parameters each reveal abnormalities in the upper and lower motor neurons even in patients with DM. The results also show a prolonged PCT in CCM-DM patients, despite having no history of diabetic neuropathy. Corticospinal tract impairments are similar between CCM and CCM-DM patients, while the JOA score of the CCM-DM patients is lower than that in the CCM patients. The JOA score in CCM-DM patients may be influenced by additional impairments in peripheral nerves or other diabetic complications. These electrophysiological studies may be useful for screening motor pathway function for CCM in patients with DM.

Electrophysiological evidence of functional improvement in the corticospinal tract after laminoplasty in patients with cervical compressive myelopathy: clinical article.

OBJECT: Cervical laminoplasty is a surgical procedure for cervical compressive myelopathy (CCM), and satisfactory outcomes have been reported. However, few reports have examined the pathophysiology of improvements in spinal cord function. The aim of this study was to investigate the variation in central motor conduction time (CMCT) before and after cervical laminoplasty in patients with CCM. METHODS: Motor evoked potentials (MEPs) following transcranial magnetic stimulation and compound muscle action potentials (CMAPs) and F-waves following electrical stimulation of the ulnar and tibial nerves at the wrist and ankle were measured from the abductor digiti minimi muscle (ADM) and abductor hallucis muscle (AH) in 42 patients with CCM before and 1 year after cervical laminoplasty. The peripheral conduction time (PCT) was calculated as follows: (latency of CMAPs + latency of F-waves - 1)/2. The CMCT was calculated by subtracting the PCT from the onset latency of the MEPs. The CMCT recovery ratio was defined and calculated as the ratio of CMCT values 1 year after surgery to those before surgery. The CMCT data were analyzed as longer or shorter CMCT between the patients' right and left ADMs and AHs. The Japanese Orthopaedic Association (JOA) score for cervical myelopathy was obtained as a clinical outcome before and 1 year after surgery. The recovery rate (RR) 1 year after surgery was calculated using the following formula: (postoperative JOA score 1 year after surgery - preoperative JOA score)/(17 - preoperative JOA score) × 100. Correlations among CMCT parameters, patient age, JOA score, and RR were determined. RESULTS: The longer and shorter CMCTs from the ADM (longer, p = 0.000; shorter, p = 0.008) and the longer CMCT from the AH (longer, p = 0.000) before surgery decreased significantly 1 year after surgery; the shorter CMCT from the AH did not significantly differ (shorter, p = 0.078). The mean JOA score before surgery was 10.1 ± 3.0 and improved significantly to 12.9 ± 2.7 at 1 year after surgery (p = 0.000). The mean CMCT recovery ratio and RR were 0.91 ± 0.18 and 0.43 ± 0.27, respectively. The longer/shorter CMCT parameters in the ADM and AH before or 1 year after surgery correlated significantly with the JOA score both before and 1 year after surgery. The CMCT recovery ratio from the longer CMCT in the ADM correlated significantly with the RR (r = - 3090, p = 0.011). There were no significant correlations between age and any CMCT parameters or CMCT recovery ratios. CONCLUSIONS: These results suggest that cervical laminoplasty improves corticospinal tract function 1 year after surgery, which may be one of the reasons for the JOA score improvements in patients with CCM. The degree of improvement in corticospinal tract function did not correlate with patient age in this case series. The results demonstrated quantitative evidence of the pathophysiology of functional recovery in the corticospinal tract following cervical laminoplasty in patients with CCM.

Administration of microRNA-210 promotes spinal cord regeneration in mice.

STUDY DESIGN: Experimental animal study of treatment of spinal cord injury (SCI). OBJECTIVE: To investigate the therapeutic effects of administering microRNA-210 (miR-210) to promote angiogenesis in a mouse SCI model. SUMMARY OF BACKGROUND DATA: Despite many previous studies regarding SCI, there is no established treatment in clinical practice. miRNAs have attracted immense attention because of their crucial role in human disease, and they have been proposed as potential new therapeutic targets for SCI. METHODS: At specific times after administration, mice were analyzed by several methods to examine the distribution of miR-210, histological angiogenesis and neurogenesis, functional recovery from SCI, and the expression levels of target genes of miR-210. RESULTS: After injection of miR-210 into the lesion of the injured spinal cord, expression of endogenous miR-210 increased until 6 days after injection. The administration of miR-210 promoted angiogenesis and astrogliosis, and improved functional recovery after SCI compared with the noninjected controls. Furthermore, the area made up of axons and myelin in the spinal cord tissues caudal to the injury site was larger in mice injected with miR-210 than those of the controls. Apoptotic cell death was lower in mice administered miR-210. After administration of miR-210, the expressions of protein-tyrosine phosphate 1B and ephrin-A3, both gene targets of miR-210, were downregulated at the protein level and protein-tyrosine phosphate 1B expression was also downregulated at the transcriptional level. CONCLUSION: MiR-210 might contribute to spinal cord repair by promoting angiogenesis via the inhibition of protein-tyrosine phosphate 1B and ephrin-A3. LEVEL OF EVIDENCE: N/A.

Therapeutic effect and risk factors for complications of excision in 76 patients with schwannoma.

BACKGROUND: Benign schwannoma is the most common tumor of peripheral nerves. However, the clinical course of excision and risk factors associated with postoperative neurological deficits are not well known. We evaluated the incidence of preoperative symptoms, the incidence of postoperative neurological deficits, and the risk factors of neurological deficits. METHODS: We retrospectively reviewed data of 76 patients with schwannomas treated at our institution. We reviewed the clinical characteristics, and postoperative results, and determined the possible risk factors influencing the development of complications. RESULTS: Excision of schwannoma improved the Tinel-like signs in 47 of 51 patients and spontaneous pain in 14 of 15. Eleven of 17 patients with sensory deficits showed complete recovery, but six continued to show deficits with or without improvement. Motor deficits that were observed in four patients persisted in one. New neurological deficits developed in 21 patients and persisted until final follow-up in 8. Tinel-like signs was the risk factor of surgery-related neurological deficits (p = 0.009). CONCLUSIONS: New deficits developed predominantly in patients with preoperative Tinel-like signs. Attention should be given to patients with the factor.