Mitsunori Yoshimoto

Piriformis Syndrome Resulting From a Rare Anatomic Variation

Study Design. Case report. Objectives. We report a rare case of piriformis syndrome accompanying anatomic variation in the piriformis muscle and sciatic nerve. Summary of Background Data. Beaton classified anatomic variation in the piriformis muscle and sciatic nerve into 6 types based on cadaver studies. There has been no report in the English literature of surgical treatment for a case of piriformis syndrome accompanying Beaton type d anatomic variation. Methods. A patient with sciatica showing no nerve root compression in lumbar MRI underwent pelvic MRI and perineurography of the sciatic nerve followed by CT. The findings in these images suggested piriformis syndrome accompanying anatomic variation of the piriformis muscle and sciatic nerve. Surgical treatment was performed. Results. Surgical exploration of the piriformis muscle revealed Beaton type d anatomic variation. Both anterior and posterior lobes of the piriformis muscle were resected. The pain in the leg had completely disappeared after surgery. Conclusions. This is a very rare case of surgically treated piriformis syndrome resulting from type d anatomic variation in Beaton’s classification. Pelvic MRI and perineurography of the sciatic nerve were useful for diagnosis in this case.

Diagnostic features of sciatica without lumbar nerve root compression.

Study Design Retrospective case series review of patients showing sciatica without radiographic evidence of nerve root compression. Objective To elucidate clinical features of sciatica caused by extralumbar spinal lesions. Summary of Background Data Sciatica caused by extralumbar spinal lesions has been reported sporadically. Given the paucity of case series studies, however, the pathology and clinical features of such sciatica remain not fully understood. Methods Sixty-one patients who presented with persistent sciatica were examined with lumbar magnetic resonance (MR) imaging. Of these, the records of patients showing no detectable nerve root compression in MR images were reviewed with respect to demographics, neurologic status, further diagnostic procedures, treatments, and treatment outcomes. Results Of 61 patients, 10 (16.4%) showed sciatica and a lack of nerve root compression in the lumbar MR imaging. In demographics, there was female sex dominance (9 patients) and right side preference (9 patients). Eight patients exhibited sensory disturbance beyond a single dermatome. Piriformis syndrome was diagnosed in 3 patients and 5 patients were considered to have sacral plexus pathologies associated with gynecologic conditions such as ectopic endometriosis, ovarian cyst, and pregnancy. A review of the literature also supported the right side preference in sciatica associated with gynecologic conditions. Conclusions Piriformis syndrome and gynecologic conditions account for most cases of extralumbar spinal sciatica. Female sex, right side involvement, and overlapping sensory disturbance are suggestive of extralumbar spinal sciatica associated with gynecologic conditions.

Efficacy of diffusion-weighted magnetic resonance imaging in diagnosing spinal root disorders in lumbar disc herniation.

Study Design. Prospective study based on magnetic resonance imaging for lumbar disc herniation. Objective. In this study, we captured diffusion-weighted imaging (DWI) of dorsal root ganglion (DRG) of the affected nerve root in lumbar disc herniation and examined the relationship between apparent diffusion coefficient (ADC) and clinical symptoms to evaluate the efficacy of DWI in the diagnosis of lumbar spinal disorders. Summary of Background Data. DWI captures diffusion of water molecules in intracellular or extracellular fluid, allowing visualization of edematous changes, and is therefore used in diagnosis of hyper-acute cerebral infarction. In addition, it is possible to quantify the degree of diffusion using ADC calculated from the DWI data. Meanwhile in lumbar disc herniation, edematous changes occur in DRG of affected nerve root. If DWI enables visualization of these edematous changes, it will be possible to diagnose objectively the affected level. Methods. The subjects were 30 patients who underwent surgery of unilateral radiculopathy and a single level lumbar disc herniation. We analyzed the relationship between morbidity duration, visual analogue scale (VAS) score of leg symptoms, and ADC. In addition, we investigated any correlation between VAS recovery ratio (i.e., VAS preoperative − VAS postoperative)/VAS preoperative × 100) with ADC. Results. When compared with the contralateral side, ADC of the affected DRG was observed to increase in 18 and decrease in 12 subjects, and thus no definite trend was observed. The relationship between morbidity duration, VAS score, and ADC had no observed correlation. A positive correlation between ADC and VAS recovery ratio was statistically observed (P < 0.01, leg pain: r = 0.707, leg numbness: r = 0.738). Conclusion. This study showed that patients with decreased ADC tended to show poor improvement of leg symptoms, which may suggest the possibility that ADC of DRG is related to neuronal plasticity. Level of Evidence: 2

Microendoscopy-assisted muscle-preserving interlaminar decompression for lumbar spinal stenosis: clinical results of consecutive 105 cases with more than 3-year follow-up.

Study Design. A retrospective review of data collected prospectively on patients who underwent microendoscopy-assisted muscle-preserving interlaminar decompression (MILD) for lumbar spinal stenosis. Objective. To evaluate the clinical results including surgical invasiveness and reduction rate of facet joint with a follow-up of more than 3 years. Summary of Background Data. Hatta et al reported microscopic posterior decompression procedure, MILD for lumbar spinal stenosis with reference to the cervical central approach put forth by Shiraishi. Mikami et al applied spinal microendoscopy to MILD procedure (microendoscopy-assisted MILD). Methods. One hundred five consecutive patients, who underwent microendoscopy-assisted MILD, participated in this study. Operative time, blood loss, visual analogue scale (VAS), serum creatine kinase and C-reactive protein, surgical complications, reduction rate of the facet joint, Japanese Orthopaedic Association score, and Short-Form 36 were evaluated. Results. The operative time was 99.3 minutes and the intraoperative bleeding was 15.7 mL on average. The mean VAS score to assess surgical site pain was 20.6 mm on postoperative day 1. The mean serum creatine kinase on postoperative day 1 and C-reactive protein on postoperative day 3 were 145.4 IU/L and 2.7 mg/dL, respectively. Surgical complications were identified in 2 cases, cauda equina injury and dural tear. The mean reduction rate of the facet joint was 3%. The follow-up rate was 83.3% and the mean follow-up period was 52.7 months. The Japanese Orthopaedic Association score improved significantly from 14.8 to 23.7 points on average. Significant improvements in Short-Form 36 were observed in all subscales except in General Health. Revision surgical procedures were performed in 8 cases at the operated level including 4 of juxtafacet cyst, 3 of disc herniation, and 1 of insufficient decompression. Conclusion. Microendoscopy-assisted MILD is a minimally invasive procedure and favorable clinical results can be expected for lumbar spinal stenosis. Level of Evidence: 4

TNP-470 Suppresses the Tumorigenicity of HT1080 Fibrosarcoma Tumor Through the Inhibition of VEGF Secretion From the Tumor Cells.

Angiogenesis inhibitors are a novel class of promising therapeutic agents for treating cancer. TNP-470, a systemic analogue of fumagillin, is an angiogenesis inhibitor capable of suppressing the tumorigenicity in several animal models even though the mechanisms of action have not been completely clarified. In the current study, we investigated the effects of TNP-470 on human fibrosarcoma cells in vivo and in vitro. The administration of TNP-470 could suppress the tumorigenicity of HT1080 fibrosarcoma tumor. The conditioned medium from HT1080 fibrosarcoma cells treated with TNP-470 inhibited the proliferation and migration of human endothelial cell line, HUVEC and ECV304. The concentration of VEGF in the conditioned medium from HT1080 cells treated with TNP-470 was lower than that of the cells without TNP-470 treatment, indicating that TNP-470 downregulates the secretion of VEGF from HT1080 cells. These findings strongly suggest that the direct action of TNP-470 on sarcoma cells inhibits angiogenesis through the downregulation of VEGF secretion and this angiogenesis suppression resulted in the inhibition of tumorigenicity of HT1080 fibrosarcoma tumo.

Microendoscopic Discectomy for Far Lateral Lumbar Disk Herniation: Less Surgical Invasiveness and Minimum 2-Year Follow-Up Results

Study Design: A retrospective review of data collected prospectively on 24 consecutive patients who underwent microendoscopic discectomy (MED) for far lateral lumbar disk herniation. Objective: To evaluate the level of surgical invasiveness of the procedure and clinical results with a follow-up of at least 2 years. Summary of Background Data: To the best of our knowledge, there have only been 2 small-size and short-term clinical studies reporting the feasibility of MED for far lateral lumbar disk herniation, despite its relatively long history. Moreover, these 2 articles did not include detailed evaluations of surgical invasiveness and did not comprise any cases with disk herniation at L5-S1, which should account for a considerable proportion of cases. Methods: Twenty-four consecutive patients, including L5-S1 patients, who underwent MED for far lateral lumbar disk herniation participated in this study. Ninety-three consecutive patients with intracanalicular disk herniation, who underwent MED also participated as control subjects. Operative time, intraoperative blood loss, serum C-reactive protein and creatine kinase, visual analog scale, and Japanese Orthopaedic Association score were evaluated. Results: The procedure was successfully performed in all cases. The operative time in patients with far lateral disk herniation (143.9 min) was significantly longer than in patients with intracanalicular disk herniation (90.2 min) (P<0.01). There were no differences between the groups in terms of intraoperative blood loss (39.6 and 40.4 mL, respectively), serum C-reactive protein level on postoperative day 3 (0.71 and 0.73 mg/dL), serum creatine kinase level on postoperative day 1 (161.8 and 225.7 IU/L), visual analog scale scores to assess surgical site pain on the first postoperative day (19.4 and 24.0 mm), or improvement rate in Japanese Orthopaedic Association score at final follow-up (76.0% and 77.0%). Conclusions: MED is a well-balanced technique which offers both reduced invasiveness and good clinical results without sacrificing reliability.

Complications Associated With Spine Surgery in Patients Aged 80 Years or Older: Japan Association of Spine Surgeons with Ambition (JASA) Multicenter Study:

Study Design: Retrospective study of registry data. Objectives: Aging of society and recent advances in surgical techniques and general anesthesia have increased the demand for spinal surgery in elderly patients. Many complications have been described in elderly patients, but a multicenter study of perioperative complications in spinal surgery in patients aged 80 years or older has not been reported. Therefore, the goal of the study was to analyze complications associated with spine surgery in patients aged 80 years or older with cervical, thoracic, or lumbar lesions. Methods: A multicenter study was performed in patients aged 80 years or older who underwent 262 spinal surgeries at 35 facilities. The frequency and severity of complications were examined for perioperative complications, including intraoperative and postoperative complications, and for major postoperative complications that were potentially life threatening, required reoperation in the perioperative period, or left a permanent injury. Results: Perioperative complications occurred in 75 of the 262 surgeries (29%) and 33 were major complications (13%). In multivariate logistic regression, age over 85 years (hazard ratio [HR] = 1.007, P = 0.025) and estimated blood loss ≥500 g (HR = 3.076, P = .004) were significantly associated with perioperative complications, and an operative time ≥180 min (HR = 2.78, P = .007) was significantly associated with major complications. Conclusions: Elderly patients aged 80 years or older with comorbidities are at higher risk for complications. Increased surgical invasion, and particularly a long operative time, can cause serious complications that may be life threatening. Therefore, careful decisions are required with regard to the surgical indication and procedure in elderly patients.

Risk Factors for Delirium After Spine Surgery in Extremely Elderly Patients Aged 80 Years or Older and Review of the Literature: Japan Association of Spine Surgeons with Ambition Multicenter Study

Study Design: Retrospective database analysis. Objective: Spine surgeries in elderly patients have increased in recent years due to aging of society and recent advances in surgical techniques, and postoperative complications have become more of a concern. Postoperative delirium is a common complication in elderly patients that impairs recovery and increases morbidity and mortality. The objective of the study was to analyze postoperative delirium associated with spine surgery in patients aged 80 years or older with cervical, thoracic, and lumbar lesions. Methods: A retrospective multicenter study was performed in 262 patients 80 years of age or older who underwent spine surgeries at 35 facilities. Postoperative complications, incidence of postoperative delirium, and hazard ratios of patient-specific and surgical risk factors were examined. Results: Postoperative complications occurred in 59 of the 262 spine surgeries (23%). Postoperative delirium was the most frequent complication, occurring in 15 of 262 patients (5.7%), and was significantly associated with hypertension, cerebrovascular disease, cervical lesion surgery, and greater estimated blood loss (P < .05). In multivariate logistic regression using perioperative factors, cervical lesion surgery (odds ratio = 4.27, P < .05) and estimated blood loss ≥300 mL (odds ratio = 4.52, P < .05) were significantly associated with postoperative delirium. Conclusions: Cervical lesion surgery and greater blood loss were perioperative risk factors for delirium in extremely elderly patients after spine surgery. Hypertension and cerebrovascular disease were significant risk factors for postoperative delirium, and careful management is required for patients with such risk factors.

Investigation of Intervertebral Disc and Facet Joint in Lumbar Spondylolisthesis using T2 Mapping

PURPOSE We measured T2 relaxation time of the intervertebral discs (IVD) and facet joints (FJ) in patients with degenerative spondylolisthesis (DS) and no spondylolisthesis (NS) and investigated the characteristics of these parts in DS. METHODS In 40 patients with DS and 40 patients with NS, we measured T2 relaxation time of the IVD and FJ and compared them between groups. In the group with DS, we also examined the relationship between the degree of slippage using Meyerding grade and T2 relaxation of each part in the IVD and FJ. RESULTS T2 relaxation time of the IVD tended to be lower in the DS than NS group and differed significantly (P < 0.01) within the anterior annulus fibrosus. T2 relaxation time in the FJ was significantly higher in the DS than NS group. T2 relaxation time in the FJ was significantly higher for those assessed Meyerding Grade II than Grade I, although we observed no significant differences in T2 relaxation time in any area of the IVD. CONCLUSION T2 relaxation time decreased in the anterior annulus fibrosus of the IVD and increased in the FJ in patients with DS, suggesting an association of IVD and FJ degeneration with the development of lumbar DS.

Heel cord advancement combined with Vulpius' lengthening of the gastrocnemius.

The results of Achilles tendon lengthening to treat spastic pes equinus deformity are less than satisfactory, with high recurrence rates. To improve the outcome, heel cord advancement can be done. In the current study, the patients with severe contracture of the Achilles tendon were treated by heel cord advancement. Additional lengthening of the gastrocnemius muscle using the Vulpius technique was done to reattach the Achilles tendon to the calcaneus. Seventeen patients (20 feet) with spastic pes equinus deformities were treated with this technique, and satisfactory midterm postoperative results were obtained. The mean age of the patients at surgery was 10 years, and the mean duration of followup after surgery was 8 years. The mean tibioplantar angle decreased postoperatively, and there were no recurrences of pes equinus deformity and no appearance of pes calcaneus deformity. Walking ability improved in two patients and did not deteriorate in any of the patients. Seven of the patients were able to stand on only the affected foot after the operation. Our technique provides good correction of an equinus deformity with no recurrence, and with improvement of the physical activity level. Level of Evidence: Therapeutic level, Level IV (case series—no, or historical control group). See the Guidelines for Authors for a complete description of levels of evidence.