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ObjectThe surgical approach and treatment of thoracolumbar osteoporotic vertebral collapse with neurological deficit have not been documented in detail. Anterior surgery provides good decompression and solid fusion, but the surgery-related risk is relatively higher than that associated with the posterior approach. In posterior surgery, the major problem after posterior correction and instrumentation is failure to support the anterior spinal column, leading to loss of correction of kyphosis. The aim of this study was to evaluate the efficacy of reinforcing short-segment posterior fixation with vertebroplasty and to compare the outcome with those of posterior surgery without vertebroplasty and anterior surgery, retrospectively.MethodsThe authors studied 83 patients who underwent surgical treatment for a single thoracolumbar osteoporotic vertebral collapse with neurological deficit. Twenty-eight patients treated by posterior surgery combined with vertebroplasty (Group A), 25 patients treated by posterior surgery without vertebroplasty (Group B), and 30 patients treated by anterior surgery (Group C) were followed up for a mean postoperative period of 4.4 years. Neurological outcome, visual analog scale pain score, and radiographic results were compared in the 3 groups.ResultsPostoperative (4–6 weeks) and follow-up neurological outcome and visual analog scale scores were not significantly different among the 3 groups. Postoperative kyphotic angle was significantly reduced in Group B compared with Group C (p = 0.007), whereas the kyphotic angle was not significantly different among the 3 groups at follow-up. The mean ± SD loss of correction at follow-up was 4.6° ± 4.5°, 8.6° ± 6.2°, and 4.5° ± 5.9° in Groups A, B, and C, respectively. The correction loss at follow-up in Group B was significantly higher compared with Groups A and C (p = 0.0171 and p = 0.0180, respectively).ConclusionsThe results suggest that additional reinforcement with vertebroplasty reduces the kyphotic loss and instrumentation failure, compared with patients without the reinforcement of vertebroplasty. Vertebroplasty-augmented short-segment fixation seems to offer immediate spinal stability in patients with thoracolumbar osteoporotic vertebral collapse; the effect seems equivalent to that of anterior reconstruction.

The dorsal root ganglion (DRG) should not be overlooked when considering the mechanism of low-back pain and sciatica, so it is important to understand the morphological features of the vascular system supplying the DRG. However, the neurogenic control of intraganglionic blood flow has received little attention in the past. The authors used an immunohistochemical technique to investigate the presence and distribution of autonomic and sensory nerves in blood vessels of the DRG.Ten Wistar rats were used. To investigate the mechanism of vasomotion on the lumbar DRG, the authors used immunohistochemical methods. Sections were incubated overnight with antisera to tyrosine hydroxylase (TH), aromatic L-amino-acid decarboxylase (AADC), 5-hydroxytryptamine, substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal peptide (VIP), somatostatin (SOM), neuropeptide Y (NPY), leucine-enkephalin, and cholineacetyl transferase (Ch-E). The avidin-biotin complex method was used as the immunohistochemical procedure, and the sections were observed under a light microscope.In the immunohistochemical study, TH-, AADC-, SP-, CGRP-, VIP-, SOM-, NPY-, and Ch-E-positive fibers were seen within the walls of blood vessels in the DRG. This study revealed the existence of a comprehensive perivascular adrenergic, cholinergic, and peptidergic innervation of intraganglionic blood vessels, with a possible role in neurogenic regulation (autoregulation) of intraganglionic circulation.The presence of perivascular nerve plexuses around intraganglionic microvessels suggests that autonomic nerves play an important role in intraganglionic circulation.

The effects of sagittal kyphotic deformities or mechanical stress on the development of cervical spondylotic myelopathy, or the reduction and fusion of kyphotic sagittal alignment have not been consistently documented. The aim in this study was to determine the effects of kyphotic sagittal alignment of the cervical spine in terms of neurological morbidity and outcome after 2 types of surgical intervention.The authors retrospectively reviewed the records of 476 patients who underwent cervical spine surgeries for spondylotic myelopathy between 1993 and 2006 at their university medical center. Among these were identified 43 patients-30 men and 13 women, with a mean age of 58.8 years-who had cervical kyphosis exceeding 10 degrees on preoperative sagittal lateral radiographs obtained in the neutral position, and their cases were analyzed in this study. Anterior decompression with interbody fusion was conducted in 28 patients, and en bloc open-door C3-7 laminoplasty in 15 patients. Both pre- and postoperative neurological, radiographic, and MR imaging findings were assessed in both surgical groups.The mean preoperative kyphotic angle in all 43 patients was 15.9 +/- 5.9 degrees in the neutral position. Segmental instability was noted in 26 patients (61%) and reversed dynamic spinal canal stenosis at the level above the local kyphosis in 22 (51%). Preoperative T2-weighted MR images showed high-intensity signal within the cord at and around the level of maximal compression or segmental instability in 28 patients (65%). The mean kyphotic angle in both the neutral and flexion positions was significantly smaller at 4-6 weeks after surgery in the anterior spondylectomy group than in the laminoplasty group (p0.001). Furthermore, the angle in the neutral position was significantly smaller on follow-up in the anterior spondylectomy group than in the laminoplasty group (p = 0.034). The transverse area of the spinal cord was significantly larger in the anterior spondylectomy group than in the laminoplasty group on follow-up (p = 0.037). Preoperative neurological scores (assessed using the Japanese Orthopaedic Association scale) and improvement on follow-upor = 2 years after treatment (average 3.3 years) were not significantly different between the 2 groups; however, there was a significant difference in Japanese Orthopaedic Association score at 4-6 weeks postoperatively (p = 0.047).Kyphotic deformity and mechanical stress in the cervical spine may play an important role in neurological dysfunction. In a select group of patients with kyphotic deformityor = 10 degrees , adequate correction of local sagittal alignment may help to maximize the chance of neurological improvement.

The aims of this study were to review the clinicoradiological findings in patients who underwent decompressive surgery for proximal and distal types of muscle atrophy caused by cervical spondylosis and to discuss the outcome and techniques of surgical intervention.Fifty-one patients (43 men and 8 women) with proximal (37, with arm drop) and distal muscle atrophy (14, with wrist drop) underwent cervical decompression (39 anterior decompressions and 12 open-door C3-7 laminoplasties with microsurgical foraminotomy) for muscle weakness in the upper extremities. The clinical course, type of spinal cord compression, abnormal signal intensity on high-resolution MR imaging, and postdecompression improvement in muscle power were reviewed at a mean follow-up of 2.6 years (range 0.8-9.4 years).The most commonly affected vertebrae were C4-5 and C5-6, and C5-6 and C6-7 in patients with proximal or distal muscle atrophy, respectively; the respective numbers of affected vertebrae were 1.5 and 2.2. Transaxial MR imaging showed medial compression of the spinal cord in 20 patients (in 12 with proximal and 8 with distal muscle atrophy), paramedial compression in 22 (17 and 5 patients, respectively), and foraminal compression in 9 (8 and 1 patient, respectively). Increased signal intensity on MR imaging was observed in 85.0, 22.7, and 11.1% of cases of medial, paramedial, and foraminal compression, respectively. Increased signal intensity at the affected muscle segment level was observed in 52.9, 40.0, and 0% of cases, respectively. Sixty-two percent of patients with proximal muscle atrophy gained 1 or more grades of muscle power on manual muscle testing (MMT), whereas 64.3% with distal muscle atrophy failed to gain even 1 grade of improvement. The recovery of muscle power correlated with disease duration and the percent voltage of Erb point or wrist-stimulated muscle evoked potentials but not with preoperative MMT, longitudinal range of spinal cord compression, signal change on T2-weighted MR imaging, or surgical procedure.Surgical outcome in patients with distal muscle atrophy was inferior to that in patients with proximal atrophy. The distal type was characterized by a long preoperative period, a greater number of cervical spine misalignments, a narrow spinal canal, and increased signal intensity on T2-weighted MR imaging. It is essential to perform a careful neurological evaluation, including sensory examination of the lower limbs, as well as neuroradiological and neurophysiological assessments to avoid confusion with motor neuron disease and to detect the coexistence of amyotrophic lateral sclerosis, especially when surgical treatment of cervical spondylosis is planned. The results of careful physical examination, MR imaging studies, and electromyography studies should be comprehensively evaluated to ascertain the pathophysiology of the muscle atrophy. It is very important to distinguish the pathophysiology caused by nerve root impingements from anterior horn dysfunction when making decisions about treatment strategy. Surgical treatment--with or without foraminotomy--for amyotrophy in cervical spondylosis requires urgent action with regard to human neuroanatomy and neural innervation of the paralyzed muscles.

Object In this paper the authors' goal was to identify histological and immunohistochemical differences between cervical disc herniation and spondylosis. Methods A total of 500 cervical intervertebral discs were excised from 364 patients: 198 patients with disc herniation and 166 patients with spondylosis. We examined en bloc samples of endplate-ligament-disc complexes. Types of herniation and graded degrees of disc degeneration on MR images were examined histologically and immunohistochemically. Results The herniated discs showed granulation tissue, newly developed blood vessels, and massive infiltration of CD68-positive macrophages, which surrounded the herniated tissue mainly in the ruptured outer layer of the anulus fibrosus. The vascular invasion was most significant in uncontained (extruded)-type herniated discs. Chondrocytes positive for matrix metalloproteinase (MMP)–3, tumor necrosis factor (TNF)–α, basic fibroblast growth factor (bFGF), and vascular endothelial growth factor (VEGF) were abundant in both herniated and spondylotic discs. Free nerve fibers, positive for nerve growth factor (NGF), neurofilament 68, growth-associated protein (GAP)-43, and substance P, were strongly apparent in and around the outer layer of uncontained (extruded)-type herniated discs, with enhanced expression of NGF. The authors observed that herniated discs showed more advanced degeneration in the outer layer of the anulus fibrosus around the granulation tissue than spondylotic discs. On the other hand, spondylotic discs showed more advanced degeneration in the cartilaginous endplate and inner layer of the anulus fibrosus than herniated discs. Spondylotic discs also had thicker bony endplates and expressed TNFα and MMP-3 more diffusely than herniated discs, especially in the inner layer of the anulus fibrosus. Conclusions The authors' results indicate that herniated and spondylotic intervertebral discs undergo different degenerative processes. It is likely that TNFα, MMP-3, bFGF, and VEGF expression is upregulated via the herniated mass in the herniated intervertebral discs, but by nutritional impairment in the spondylotic discs. Macrophage accumulation around newly formed blood vessels in the herniated disc tissues seemed to be regulated by MMP-3 and TNFα expression, and both herniated and spondylotic discs exhibited marked neoangiogenesis associated with increased bFGF and VEGF expression. Nerve fibers were associated with NGF overexpression in the outer layer of the anulus fibrosus as well as in endothelial cells of the small blood vessels.

Object. The authors studied the histological and immunohistochemical features of ossified posterior longitudinal ligament (PLL) of the cervical spine, especially in the calcification and ossification front. Methods. Samples of en bloc ossified PLL plaque obtained in 31 patients were stained with H & E and immuno-histochemically prepared for collagens (types I and II), vascular endothelial growth factor (VEGF), transforming growth factor (TGF)–β, and bone morphogenetic protein (BMP)–2, and by terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end labeling method for apoptosis. Results. Enchondral ossification was evident between the ligamentous enthesis and deep layer of the ligament, with irregularly disorganized arrangement of elastic fibers in association with advancement of the degenerative process. In the ossification front, many hypertrophic metaplastic chondrocytes were noted in the ossifying plaque immediately contiguous to the ligament fibers, together with a considerable degree of neovascularization. Both TGFβ and BMP-2 were highly expressed in metaplastic hypertrophic chondrocytes in the ossification front, and BMP-2 was also expressed in fibroblastic cells near the ossified PLL plaque. Expression of type I collagen was significant in the matrix of the ossified PLL lesion, whereas that of type II was marked in metaplastic chondrocytes in the ossification front. Apoptotic hypertrophic chondrocytes were observed mainly in the fibrocartilaginous area near the calcification front. Conclusions. The enchondral ossification process in the ossified PLL was closely associated with degenerative changes of elastic fibers and cartilaginous cartilage formation, together with the appearance of metaplastic hypertrophic cartilage cells and neovascularization. The authors also found that VEGF-positive metaplastic chondrocytes in the ossification front and different expression patterns of collagens probably play some role in the extension of the ossified PLL from the ossification front.

ObjectThe authors investigated the usefulness of using an expandable cage strut in anterior reconstruction after osteoporotic vertebral collapse in patients with neurological deficits.MethodsTwenty-eight patients who had undergone expandable cage strut–augmented anterior thoracolumbar reconstruction participated in a follow-up review for a mean of 4.9 years. Radiographs were reviewed for kyphosis, lateral tilt of the implant, cage subsidence, the presence of a solid fusion mass, and instrumentation failure. Changes in neurological status and visual analog scale (VAS) pain score, as well as technique-related complications, were examined.The mean angles ± the standard deviations of kyphosis correction 4 to 6 weeks after surgery and at final follow-up examination were 10.4 ± 7.6° and 5.6 ± 6.0°, respectively. The mean subsidence of the expandable cage within the adjacent vertebrae was 2.5 ± 3.0 mm at the final follow-up examination. Neurological improvement at the final follow up was more significant in patients with Type 1 (wedge-type) than Type 2 (flat-type) (p = 0.037) or Type 3 (concave-type) (p = 0.006) vertebral collapse. Follow-up VAS scores were significantly higher in patients with Type 1 than Type 3 collapse (p = 0.012). In all cases the authors observed solid union with incorporation of the cage. There were no surgery-related complications.ConclusionsAn expandable titanium cage strut seems useful in vertebral body replacement in patients with osteoporotic thoracolumbar collapse. Favorable results were obtained in cases of Type 1 collapse (wedge type) in which the middle and posterior columns remained comparatively intact.