Yoshihito Sakai

Comparison of surgical outcomes between macro discectomy and micro discectomy for lumbar disc herniation: a prospective randomized study with surgery performed by the same spine surgeon.

Study Design A prospective study was conducted on the surgical procedures for lumbar disc herniation. Objective The objective of this study is to investigate the surgical outcomes of different methods when performed by the same surgeon, using a prospective study. Background Macro discectomy is widely known as a common surgical procedure for lumbar disc herniation, while microdiscectomy in place of Caspar technique (the Caspar method) and microendoscopic discectomy by a posterior approach are reported as less invasive surgical methods for this condition. However, there have not been a significant number of prospective studies conducted to compare different surgical procedures for lumbar disc herniation. Materials and Methods The target of our study was a group of 62 patients (male: 43, female: 19) who underwent surgery by macro discectomy (A group) and 57 patients (male: 33, female: 24) who underwent surgery by microdiscectomy in place of Caspar technique (B group). The mean ages at surgery were 34 (14 to 62) years and 41 (18 to 65) years respectively, and the mean duration of follow-up was 2 years and 8 months (12 months to 4 years). For all patients, the surgery was performed by 1 of the authors. The items investigated were the operation time, amount of bleeding, duration of hospitalization, amount of analgesic agent used after surgery, pre- and postoperative scores based on judgment criteria for treatment of lumbar spine disorders established by the Japanese Orthopaedic Association score, visual analog scales (VAS, 0 to 10) for lumbago before surgery and at discharge, VAS for sciatica before surgery and at discharge, perioperative complications, and cases requiring further surgery. Results There were no significant differences between the 2 surgical procedures in the frequency of use of an analgesic agent after surgery, the pre- and postoperative Japanese Orthopaedic Association scores or postoperative VAS for sciatica. Statistically significant differences were observed in the operation time, amount of bleeding, duration of hospitalization, and postoperative VAS for lumbar pain, but the differences were not large, and may not have been clinically significant. Conclusions For herniotomy for lumbar disc herniation, both macro discectomy and microdiscectomy are appropriate, as long as surgeons have mastery of the procedures.

High prevalence of sarcopenia and reduced leg muscle mass in Japanese patients immediately after a hip fracture.

Aim:  Sarcopenia‐related falls and fractures are becoming an emerging problem as a result of rapid aging worldwide. We aimed to investigate the prevalence of sarcopenia by estimating the muscle mass of the arms and legs of patients with and without hip fracture.

Segmental pedicle screwing for idiopathic scoliosis using computer-assisted surgery.

Study Design Retrospective clinical study. Objectives To evaluate the accuracy of computer-assisted surgery for idiopathic scoliosis. Summary of Background Data Segmental pedicle screw fixation has been proven to enable enhanced correction of scoliotic deformities. However, both neurovascular and visceral structures are at potential risk from screw misplacement due to pedicle drift. No reports exist on the accuracy and benefits of computer-assisted surgery for pedicle screwing in scoliosis surgery. Methods A total of 40 consecutive patients with idiopathic scoliosis were evaluated. Postoperative computed tomography was assessed for the accuracy of pedicle screw placement in 20 cases treated without a navigation system and 20 cases with a computed tomography-based navigation system. Correlations between registered levels and pedicle perforation were investigated. Results Pedicle violation was observed in 28.0% of the control group and 11.4% of the navigation group, with significant differences. No screw misplacements at the registered levels were seen, and the longer the distance between the registered level and level of screw insertion, the higher the rate of pedicle violation. No intraoperative complications caused by pedicle perforation occurred. Conclusions In the navigation group, a tendency to lateral perforation at the concave side and medial perforation at the convex side was noted, like in the control group. Use of the navigation system significantly reduced the screw misplacement rate for rotated vertebrae as compared with the control group. Separate registration is recommended for rotated vertebrae when possible.

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.

Surgical results of intramedullary spinal cord tumor with spinal cord monitoring to guide extent of resection.

OBJECT The authors investigated the outcome of intramedullary spinal cord tumor surgery, focusing on the effect of preoperative neurological status on postoperative mobility and the extent of tumor excision guided by intraoperative spinal cord monitoring prospectively. METHODS Intramedullary spinal cord tumor surgery was performed in 131 patients between 1997 and 2007. The authors compared the pre- and postoperative neurological status and examined the type of surgery in 106 of these patients. A modified McCormick Scale (Grades I-V) was used to assess ambulatory ability (I = normal ambulation; II = mild motor sensory deficit, independent without external aid; III = independent with external aid; IV = care required; and V = wheelchair required). The type of surgery was classified into 4 levels: total resection, subtotal resection, partial resection, and biopsy. RESULTS The 106 patients consisted of 47 females and 59 males, whose average age was 42.5 years (range 6-75 years). The mean follow-up period was 7.3 years (range 2.5 months-21 years). The tumor types included astrocytoma (12 cases), ependymoma (46 cases), hemangioblastoma (16 cases), cavernous hemangioma (17 cases), and others (15 cases overall: gangliocytoma, 1; germ cell tumor, 1; lymphoma, 3; neurinoma, 1; meningioma, 1; oligodendroglioma, 1; sarcoidosis, 2; glioma, 1; and unknown, 4). Initial total excision, subtotal resection, partial resection, biopsy, and duraplasty were performed in 59, 12, 22, 12, and 1 patients, respectively. According to the preoperative McCormick Scale, ambulatory status was classified as Grades I, II, III, IV, and V in 41(38%), 30 (28%), 14 (13%), 19 (19%), and 2 (2%) patients, respectively. Thirty-three (31%) of 106 patients suffered postoperative neurological deterioration. The number of patients who did not lose ambulatory ability or who achieved an ambulatory status of Grade I or II postoperatively was 33 (80%), 21 (70%), 10 (71%), 8 (42%), and 1 (50%) in patients with preoperative Grades I, II, III, IV, and V, respectively. Total excision was performed in 31 (79%) of 39 patients with preoperative Grade I, 12 (40%) of 30 patients with Grade II, 7 (50%) of 14 patients with Grade III, and 9 of 21 patients (38%) with Grade IV or V, indicating that the rate of total excision was significantly higher in patients with Grade I status. CONCLUSIONS The postoperative ambulatory ability was excellent in patients with a good preoperative neurological status. Total excision in patients with Grade I or II ambulation was associated with a good prognosis for postoperative mobility. However, the rate of postoperative deterioration was 31.5%, which is relatively high, and patients should be fully informed of this concern prior to intramedullary spinal cord tumor surgery.

Surgical outcome of ossification of the posterior longitudinal ligament (OPLL) of the thoracic spine : Implication of the type of ossification and surgical options

Objective: Ossification of the posterior longitudinal ligament (OPLL) in the thoracic spine produces myelopathy through anterior spinal cord compression that is usually progressive and unaffected by conservative treatment. Therefore, early decompressive surgery is imperative. However, decompression surgery of thoracic myelopathy is difficult, and the outcome is often poor. A retrospective study was conducted to investigate the surgical outcome of 21 patients with thoracic OPLL to evaluate which type of surgical approach is better and which type of thoracic OPLL results in a better surgical outcome. Methods: A total of 21 patients with thoracic OPLL (10 men and 11 women; mean age 54 years), who underwent surgical treatment at our department from March 1985 to October 2000, were included in the study. Seven patients exhibited the flat-type OPLL and underwent either anterior decompression and fusion (one patient), anterior decompression via a posterior approach (three patients), or expansive laminoplasty (three patients). Fourteen patients exhibited the beak-type OPLL and also underwent either anterior decompression and fusion (two patients), anterior decompression via a posterior approach (six patients), or expansive laminoplasty (six patients). Results: Regarding of operative time and blood loss, there were no marked differences between the two types of OPLL, regardless of the type of surgical procedure; anterior decompression and fusion and anterior decompression via a posterior approach yielded longer operative times and larger blood loss volumes than expansive laminoplasty. Concerning clinical outcome, there were five cases of neurologic deterioration. All of the five deteriorated cases were of the beak-type OPLL treated by a posterior approach. Two of these patients were treated with expansive laminoplasty. Conclusions: There were five instances of neurologic deterioration in our thoracic OPLL series, and all of them exhibited beak-type OPLL. In the beak-type OPLL, a subtle alteration in the spinal alignment during posterior decompression procedures may increase spinal cord compression, leading to the deterioration of symptoms. A potential increase in kyphosis following laminectomy should be avoided by fixation with a temporary rod. If intraoperative monitoring suggests spinal cord dysfunction, an anterior decompression procedure should be attempted as soon as possible.

The effect of autologous fibrin tissue adhesive on postoperative cerebrospinal fluid leak in spinal cord surgery: a randomized controlled trial.

Study Design. A prospective randomized study evaluating the efficacy of autologous fibrin tissue adhesive for decreasing postoperative cerebrospinal fluid (CSF) leak in spinal cord surgery. Objective. To compare postoperative CSF leak in 3 groups (i.e., autologous fibrin tissue adhesive used, commercial fibrin glue used, and no fibrin tissue adhesive used) of patients undergoing spinal surgery who needed dural incision. Summary of Background Data. Spinal cord operations, particularly when dural incision is inevitable, sometimes involve postoperative CSF leak. Because CSF leak is a serious complication, countermeasure is necessary to prevent it after dural suture. Commercial fibrin tissue adhesive was formerly used. Because the possibility of prion infection was widely noticed, commercial fibrin tissue adhesive containing animal components has been used less often. Methods. In 13 of 39 cases in which dural incision would be made, 400 mL whole blood was drawn, and autologous fibrin tissue adhesive was made of plasma. Cases were divided into 3 groups: (1) dural closure alone, (2) use of autologous fibrin tissue adhesive after dural closure, and (3) use of commercial fibrin tissue adhesive after dural closure. The primary outcome measure was determined as postoperative (3 days) volume of drainage fluid, and results were analyzed using the analysis of variance. The secondary outcome measure was general blood test, coagulation assay, and plasma fibrinogen, and these were analyzed also using the analysis of variance. Results. There was a significant difference in the primary outcome between the autologous and control groups. No complications such as infection or continuous CSF leak were observed in any case. The mean volume of drainage fluid was 586.2 mL in the group with autologous fibrin tissue adhesive and 1026.1 mL in the group without fibrin tissue adhesive. The volume of drainage fluid was significantly lower in the former group than that in the latter group. There was no statistical difference between the volumes of the group with autologous adhesive and with commercial adhesive (639.2 mL). Conclusions. We used autologous fibrin tissue adhesive as a new sealant after dural closure instead of commercial fibrin tissue adhesive. No definitive CSF leak was observed, and the volume of drainage fluid was significantly lower in the group with autologous fibrin tissue adhesive than that in the group without fibrin tissue adhesive. The use of autologous fibrin tissue adhesive was superior to that of commercial fibrin tissue adhesive in cost.

Vertebral reconstruction with biodegradable calcium phosphate cement in the treatment of osteoporotic vertebral compression fracture using instrumentation.

Objective: To assess the efficacy of posterior instrumentation and vertebral reconstruction with biodegradable calcium phosphate cement (CPC) in the treatment of osteoporotic vertebral compression fracture with neurologic deficit. Background: Vertebroplasty consists of the injection of polymethylmethacrylate (PMMA) cement into the vertebral body. While PMMA has high mechanical strength, it cures fast and thus allows only a short handling time. Other potential problems of using PMMA injection may include damage to surrounding tissues due to the high polymerization temperature or by the toxic unreacted monomer and the lack of long-term biocompatibility. Bone mineral cements such as calcium carbonate and CPCs have a longer working time and low thermal effect. They are also biodegradable while providing good mechanical strength. However, the viscosity of injectable mineral cements is high, and the infiltration of these cements into the vertebral body has been questioned. Recently, the infiltration properties of CPC have been significantly improved, making it more suitable for injection into the vertebral bodies for vertebral reconstruction. Methods: Five patients were included in this open prospective study. Inclusion criteria were delayed collapsed vertebral compression fractures responsible for severe pain and neurologic dysfunction necessitating posterior decompression surgery. Of five patients, two were male and three were female with an average age at surgery of 80.4 years (71–85 years) and an average duration of follow-up of 2.5 years (2–3.5 years). Evaluation of clinical data was based on x-ray, Japanese Orthopaedic Association (JOA) score for low back pain (full score is 29 points), and Visual Analog Scale (VAS). Results: The levels of the delayed collapsed vertebrae were T10, L1, and L2 (for one patient each) and L4 (two patients). All patients were in poor condition, for example, renal failure, heart failure, and chronic hepatitis. The average operative time was 2 hours (1 hour 36 minutes to 2 hours 16 minutes), and intraoperative bleeding was 181 mL (85–236 mL). As for clinical symptoms, preoperative JOA score averaged 17.8 points and was improved to 26 points postoperatively, while the preoperative VAS score of 8.6 points improved to 2 points postoperatively. Morphologic evaluation showed preoperative vertebral compression ratio averaged 41% and improved to 74% immediately after the operation and finally settled at 68%. Just one of five cases experienced late vertebral collapse 3 months after the operation. Conclusion: Vertebral reconstruction with biodegradable CPC in the treatment of osteoporotic vertebral compression fracture using instrumentation was a safe and useful surgical treatment.

Postoperative instability after laminoplasty for cervical myelopathy with spondylolisthesis.

Objective: 76 patients who underwent laminoplasty for cervical spondylotic myelopathy were investigated regarding the impact of preoperative and postoperative degenerative spondylolisthesis on their neurologic outcome. Methods: Radiographs were obtained 1 year postoperatively to investigate range of motion (ROM), lordotic curvature, and postoperative spondylolisthesis. Results: By 1 year after surgery, 85% of those spondylolistheses present preoperatively had either resolved or improved on neutral lateral radiographs. The cross-sectional area of the spinal cord at the site of spondylolisthesis was measured using preoperative computed tomography myelography. Clinical results were evaluated by the recovery rate using Japanese Orthopaedic Association score. Patients with posterior spondylolisthesis showed a significantly poorer postoperative recovery rate. Intervertebral ROM in patients with preoperative spondylolisthesis was reduced, whereas cervical alignment had not deteriorated after laminoplasty. The group with posterior spondylolisthesis showed a significant reduction in the cross-sectional area of the spinal cord at the site of spondylolisthesis. Postoperative spondylolisthesis appeared in 15 patients, 10 of whom had preoperative spondylolisthesis at an adjacent site. Conclusion: The cause of poorer surgical results of those patients with preoperative posterior spondylolisthesis appears to be related to a higher degree of spinal cord compression than with preoperative anterior spondylolisthesis.

Influence of sagittal balance and physical ability associated with exercise on quality of life in middle-aged and elderly people

SummaryWe examined 304 persons (135 males and 169 females) who underwent a basic health checkup to evaluate the relationship of quality of life (QOL) with osteoporosis, spinal sagittal balance, spinal mobility, muscle strength, and physical ability, including daily exercise. QOL of middle-aged and elderly subjects was strongly related to sagittal balance and physical ability.IntroductionSpinal kyphosis with compression fracture and osteoporosis decrease QOL and increase mortality. However, it is unclear if kyphosis, spinal sagittal balance, muscle strength, and physical ability influence QOL.PurposeThe goal of the study was to evaluate the relationship of QOL with osteoporosis, spinal sagittal balance, spinal mobility, back muscle strength, and physical ability, including daily exercise, in middle-aged and elderly people.MethodsThe subjects were 304 persons (135 males and 169 females) who underwent a basic health checkup. Lumbar lateral radiograph findings, sagittal balance and spinal mobility determined with SpinalMouse®, grip, back muscle strength, and 10-m gait time were evaluated.ResultsSF-36 physical component summary (PCS) scores showed a significant negative correlation with age (r = −0.375), spinal inclination angle (r = −0.322), and 10-m gait time (r = −0.470), and a significant positive correlation with percent of the young adult mean of bone mineral density (r = 0.223), lumbar lordosis angle (r = 0.184), thoracic spinal range of motion (ROM; r = 0.136), lumbar spinal ROM (r = 0.130), grip strength (r = 0.211), and back muscle strength (r = 0.301). In multiple regression analysis, age (r = −0.372, p < 0.0005), spinal inclination angle (r = −0.336, p < 0.05) and 10-m gait time (r = −2.898, p < 0.0001) were significantly associated with SF-36 PCS (R2 = 0.288). In the exercise group, SF-36 PCS scores were significantly better (p < 0.05) due to good spinal balance, thoracic spinal ROM, back muscle strength, and gait speed.ConclusionsQOL of middle-aged and elderly subjects was related to sagittal balance and physical ability. Thus, exercises for spine, muscle, and physical ability may improve QOL in middle-aged and elderly people.