Yukihiro Matsuyama

Bone union rate with autologous iliac bone versus local bone graft in posterior lumbar interbody fusion.

Study Design. A retrospective clinical study with a long-term follow-up in a single facility. Objective. The purpose of this study is to compare bone union rate between autologous iliac crest bone graft and local bone graft in patients treated by posterior lumbar interbody fusion (PLIF) using carbon cage for single-level interbody fusion. Summary of Background Data. Recently, a number of authors have reported on local bone grafting using bone that is obtained from laminectomy, and have indicated that the achieved fusion rate is similar to that of autologous iliac bone grafting. However, there is no report comparing the fusion rates between autologous iliac bone and local bone graft with a detailed follow-up of fusion progression. Methods. The subjects were 101 patients whose course could be observed for at least 2 years. The diagnosis was lumbar spinal canal stenosis in 14 patients, herniated lumbar disc in 19 patients, and degenerative spondylolisthesis in 68 patients. Single interbody PLIF was performed using iliac bone graft in 54 patients and local bone graft in 47 patients. Existence of pseudarthrosis on X-P (anteroposterior and lateral view) was investigated during the same follow-up period. Results. No significant differences were found in operation time and blood loss. Significant differences were also not observed in fusion grade at any follow-up period or in fusion progression between the 2 groups. Donor site pain continued for more than 3 months in 6 cases (11%). The final fusion rate was 94.5% versus 95.8%. Conclusion. Fusion results from the local bone group and the autologous iliac bone group were nearly identical. Furthermore, fusion progression was nearly identical. Complications at donor sites were seen in 17% of the cases. From the aforementioned results, it was concluded that local bone graft is as beneficial as autologous iliac bone graft for PLIF at a single level.

Influence of spinal sagittal alignment, body balance, muscle strength, and physical ability on falling of middle-aged and elderly males

ObjectiveRisk factors for falling in elderly people remain uncertain, and the effects of spinal factors and physical ability on body balance and falling have not been examined. The objective of this study was to investigate how factors such as spinal sagittal alignment, spinal range of motion, body balance, muscle strength, and gait speed influence falling in the prospective cohort study.MethodsThe subjects were 100 males who underwent a basic health checkup. Balance, SpinalMouse® data, grip strength, back muscle strength, 10-m gait time, lumbar lateral standing radiographs, body mass index, and fall history over the previous year were examined. Platform measurements of balance included the distance of movement of the center of pressure (COP) per second (LNG/TIME), the envelopment area traced by movement of the COP (E AREA), and the LNG/E AREA ratio. The thoracic/lumbar angle ratio (T/L ratio) and sagittal vertical axis (SVA) were used as an index of sagittal balance.ResultsLNG/TIME and E AREA showed significant positive correlations with age, T/L ratio, SVA, and 10-m gait time; and significant negative correlations with lumbar lordosis angle, sacral inclination angle, grip strength and back muscle strength. Multiple regression analysis showed significant differences for LNG/TIME and E AREA with T/L ratio, SVA, lumbar lordosis angle and sacral inclination angle (R2xa0=xa00.399). Twelve subjects (12xa0%) had experienced a fall over the past year. Age, T/L ratio, SVA, lumbar lordosis angle, sacral inclination angle, grip strength, back muscle strength, 10-m gait time, height of the intervertebral disc, osteophyte formation in radiographs and LNG/E AREA differed significantly between fallers and non-fallers. The group with SVAxa0>xa040xa0mm (nxa0=xa018) had a significant higher number of subjects with a single fall (6 single fallers/18: pxa0=xa00.0075) and with multiple falls (4 multiple fallers/18: pxa0=xa00.0095).ConclusionGood spinal sagittal alignment, muscle strength and 10-m gait speed improve body balance and reduce the risk of fall. Muscle strength and physical ability are also important for spinal sagittal alignment. Body balance training, improvement of physical abilities including muscle training, and maintenance of spinal sagittal alignment can lead to prevention of fall.

Bone union rate with autologous iliac bone versus local bone graft in posterior lumbar interbody fusion (PLIF): a multicenter study.

PurposeThe purpose of this study is to compare bone union rate between autologous iliac bone and local bone graft in patients treated by posterior lumbar interbody fusion (PLIF) using carbon cage for single level interbody fusion.MethodsThe subjects were 106 patients whose course could be observed for at least 2xa0years. The diagnosis was lumbar spinal canal stenosis in 46 patients, herniated lumbar disk in 12 patients and degenerative spondylolisthesis in 51 patients. Single interbody PLIF was done using iliac bone graft in 53 patients and local bone graft in 56 patients. Existence of pseudo-arthrosis on X-P (AP and lateral view) was investigated during the same follow up period.ResultsNo significant differences were found in operation time and blood loss. Significant differences were also not observed in fusion grade at any follow up period or in fusion progression between the two groups. Donor site pain continued for more than 3xa0months in five cases (9xa0%). The final fusion rate was 96.3 versus 98.3xa0%.ConclusionsAlmost the same results in fusion were obtained from both the local bone group and the autologous iliac bone group. Fusion progression was almost the same. Complications at donor sites were seen in 19xa0% of the cases. From the above results, it was concluded that local bone graft is as beneficial as autologous iliac bone graft for PLIF at a single level.

The cutoff amplitude of transcranial motor-evoked potentials for predicting postoperative motor deficits in thoracic spine surgery.

Study Design. Prospective clinical study of intraoperative transcranial motor-evoked potentials (TcMEP) amplitudes and postoperative motor deficits. Objective. To determine the cutoff amplitude during intraoperative TcMEP monitoring for predicting postoperative motor deficits after thoracic spine surgery. Summary of Background Data. Several alarm points when monitoring with TcMEP have been advocated, but there have been no reports on an actual cutoff amplitude of TcMEP for predicting the occurrence of postoperative motor deficits. Methods. Among 80 consecutive surgical cases, 28 had a deterioration in TcMEP amplitude in at least 1 monitored muscle during surgery. We examined intraoperative electrophysiological changes and postoperative motor deficits in 270 monitorable muscles in those 28 patients. Through receiver operating characteristic curve analysis, we identified the cutoff amplitudes at the intraoperative point of deterioration and at the end of surgery for predicting postoperative motor deficits in both relative and absolute values. Results. The relative and the absolute cutoff amplitudes of TcMEP at the intraoperative point of deterioration and at the end of thoracic spine surgery were 12% of control amplitude and 1.9 &mgr;V and 25% of control amplitude and 3.6 &mgr;V, respectively. Sensitivity/specificity for those cutoff points are 88%/64%, 69%/83%, 90%/64%, and 70%/82%, respectively. Conclusion. We determined the cutoff amplitude for predicting postoperative motor deficits in thoracic spine surgery. The results may help establish the alarm criteria for thoracic spine surgery.

Ablation of keratan sulfate accelerates early phase pathogenesis of ALS.

Biopolymers consist of three major classes, i.e., polynucleotides (DNA, RNA), polypeptides (proteins) and polysaccharides (sugar chains). It is widely accepted that polynucleotides and polypeptides play fundamental roles in the pathogenesis of neurodegenerative diseases. But, sugar chains have been poorly studied in this process, and their biological/clinical significance remains largely unexplored. Amyotrophic lateral sclerosis (ALS) is a motoneuron-degenerative disease, the pathogenesis of which requires both cell autonomous and non-cell autonomous processes. Here, we investigated the role of keratan sulfate (KS), a sulfated long sugar chain of proteoglycan, in ALS pathogenesis. We employed ALS model SOD1G93A mice and GlcNAc6ST-1−/− mice, which are KS-deficient in the central nervous system. Unexpectedly, SOD1G93AGlcNAc6ST-1−/− mice exhibited a significantly shorter lifespan than SOD1G93A mice and an accelerated appearance of clinical symptoms (body weight loss and decreased rotarod performance). KS expression was induced exclusively in a subpopulation of microglia in SOD1G93A mice, and became detectable around motoneurons in the ventral horn during the early disease phase before body weight loss. During this phase, the expression of M2 microglia markers was transiently enhanced in SOD1G93A mice, while this enhancement was attenuated in SOD1G93AGlcNAc6ST-1−/− mice. Consistent with this, M2 microglia were markedly less during the early disease phase in SOD1G93AGlcNAc6ST-1−/− mice. Moreover, KS expression in microglia was also detected in some human ALS cases. This study suggests that KS plays an indispensable, suppressive role in the early phase pathogenesis of ALS and may represent a new target for therapeutic intervention.

The effects of surgery on locomotion in elderly patients with cervical spondylotic myelopathy

PurposeThis study aimed to evaluate the effects of surgery on locomotor ability in patients with cervical spondylotic myelopathy (CSM) and compare the results between elderly and younger patients.MethodsA total of 369 consecutive patients who underwent expansive laminoplasty for CSM were prospectively analysed. Patients were divided into two age groups of ≥75xa0years (elderly group, 76 patients) and <75xa0years (younger group, 293 patients). Locomotor ability was estimated using part of the functional independence measure (FIM). The sum of gait and stairs items [functional independence measure (locomotion), FIM-L; possible scores, 2–14] and neurological status were estimated using the Japanese Orthopaedic Association (JOA) score (possible score, 0–17). Pre-operative neurological anamnesis was reviewed, and the surgical results of elderly patients with or without co-existing neurological history were evaluated to determine the origin of locomotor disability.ResultsPeri-operative FIM-L and JOA scores were significantly lower in the elderly group than in the younger group, and the opposite was true for improved FIM score. Cerebral infarction and previous lumbar surgery were identified as neurological co-morbidities in the elderly group. However, there was no significant difference in surgical results between elderly patients with and without co-existing neurological disorders.ConclusionsDecompression surgery can improve locomotor ability and decrease nursing care requirements among elderly patients with CSM. However, other neurological diseases can co-exist in elderly patients, making it difficult to diagnose the origin of locomotor disability. Therefore, detailed peri-operative work-up and timely decompression should be given priority to avoid progression towards fixed locomotor disability.

Meniscal pullout repair following meniscal ossicle resection: A case report

We present this case of a meniscal ossicle of the posterior horn of the medial meniscus that was treated by an arthroscopic ossicle resection followed by a pullout repair of the remaining meniscus. A 49-year-old businessman complained of catching and left knee pain. Radiographic and arthroscopic findings revealed a meniscal ossicle embedded in the posterior horn of the medial meniscus and posterior horn tear. After resection of the posterior horn with the ossicle, a pullout suture repair for the posterior segment of the meniscus was done to minimize the further extrusion of the meniscus. A histologic appearance supported the vestigial development of the meniscal ossicle as the etiology. This is the first report describing a repair of the meniscus after ossicle resection.

Usefulness of multi-channels in intraoperative spinal cord monitoring: multi-center study by the monitoring committee of the Japanese Society for Spine Surgery and related research

ObjectThe purpose of this study is to analyze the data in terms of the number of channels employed to examine the usefulness of multi-channels in intraoperative spinal cord monitoring.MethodsThe prerequisites for inclusion in the baseline data were as follows: (1) cases in which only CMAP monitoring was conducted; (2) cases in which monitoring was conducted under the same stimulation condition and the recording condition. Cases where inhalation anesthesia was used or muscle relaxants were used as maintenance anesthesia was excluded from the baseline data. Of the 6,887 cases, 884 cases met the criteria. The items examined for each of the different numbers of channels were the sensitivity and specificity, the false positive rate, the false negative rate, and the coverage rate of postoperative motor deficit muscles.ResultTo examine these two items in terms of the number of channels, the 4-channel group had lower sensitivity and specificity scores compared with the 8- and 16-channel groups (4 channels 73/93xa0%, 8 channels 100/97xa0%, 16 channels 100/95xa0%). Only four channels were derived for these cases and the coverage of postoperative motor deficit muscles was 38xa0% with only 30 out of the 80 postoperative motor deficit muscles in total being monitored. In the 8-channel group, it was 60xa0% with 12 of the 20 postoperative motor deficit muscles being monitored. The 16-channel group had 100xa0% coverage rate of postoperative motor deficit muscles.ConclusionWe suggest that multi-channel monitoring of at least eight channels is desirable for intraoperative spinal cord monitoring.

New Radiographic Index for Evaluating Acetabular Version

BackgroundSeveral qualitative radiographic signs have been described to assess acetabular retroversion. However, quantitative assessment of acetabular version would be useful for more rigorous research purposes and perhaps to diagnose and treat hip disorders.Questions/purposesWe developed a new quantitative index for acetabular version (p/a ratio). We determined the average p/a, compared it with previous radiographic signs for acetabular retroversion, and evaluated its relationship with anatomic acetabular version.MethodsWe calculated the p/a ratio by measuring p (distance from acetabular articular surface to posterior wall) and a (distance from acetabular articular surface to anterior wall) on plain hip AP radiographs and dividing p by a. P and a were assessed on the perpendicular bisector of the line between the teardrop and the lateral edge of the acetabulum. Using 185 hip radiographs from patients with suspected idiopathic osteonecrosis, we measured p/a and compared it with previous qualitative signs for acetabular retroversion. Using 62 hip CT images from patients with no osteoarthritis, we measured the anatomic anteversion at the height of the central femoral head and investigated its relationship with p/a.ResultsThe average p/a was 2.05 in 185 hips, and most patients with a p/a greater than 2.05 had a negative qualitative retroversion sign. A correlation was observed between central anteversion and p/a (r = 0.84).ConclusionsWe believe this ratio can be considered a simple quantitative parameter to assess acetabular version using plain AP radiographs.Level of EvidenceLevel III, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

Dumbbell-type hemangiopericytoma in the cervical spine: a case report and review

Hemangiopericytoma (HPC) is a highly vascularized mesenchymal tumor [1]. HPCs are mainly located in subcutaneous tissue and skeletal muscle, rarely within the central nervous system (CNS), and extremely rarely in the spinal canal [2–4]. HPCs in the spinal canal are either extradural or intradural. To the best of our knowledge, there are no reports on dumbbell-type intrato extradural and paravertebral HPC of the spinal cord. Moreover, our case was recurrent, but it was successfully managed by total tumor resection. A high rate of recurrence and metastasis in HPCs has been reported, and the clinical benefit from total tumor resection has been doubted by some surgeons [5, 6]. However, there is no established adjuvant therapy for HPCs, and we therefore opted for total tumor resection. Although the degree of surgical invasiveness was high, total tumor resection provided a recurrence-free period of 5 years after surgery. Here, we report a case of a rare form of cervical HPC, a dumbbell-type intrato extradural and paravertebral tumor, and review the literature on treating HPCs in the spine. Case report