Clinical Comparison of Unilateral Biportal Endoscopic Laminectomy versus Microendoscopic Laminectomy for Single-Level Laminectomy: A Single-Center, Retrospective Analysis.

BACKGROUND: The purpose of this study was to compare clinical results of microendoscopic laminectomy (MEL) with those of unilateral biportal endoscopic laminectomy (UBEL) in patients with single-level lumbar spinal canal stenosis. METHODS: The subjects consisted of 181 patients who underwent MEL (139 cases) and UBEL (42 cases) who were followed up for at least 6 months. All patients had lumber canal stenosis for 1 level. Outcomes of the patients were assessed with the duration of surgery, the bone resection area in 3-dimensional computed tomography, the facet preservation rates in computed tomography axial imagery, Visual Analog Scale (VAS) for low back pain, the Oswestry Disability Index, and the EuroQol 5-Dimensions questionnaire. RESULTS: The bone resection area in 3-dimensional computed tomography was 1.5 for MEL versus 1.0 cm2 for UBEL (P < 0.05). The facet preservation rates on the advancing side and the opposite side were 78% versus 86% (advancing side: MEL vs. UBEL) and 85% versus 94% (opposite side) (P < 0.05). The VAS (low back pain) score, VAS (leg pain), Oswestry Disability Index, and EuroQol 5-Dimension questionnaire significantly dropped in both groups at the final period (P < 0.05), however, exhibiting no difference between the 2 groups at each period. MEL resulted in greater numbers of complications, including 5 cases of hematoma paralysis, 8 cases of dura injury, 2 cases of reoperation, as opposed to zero cases of hematoma paralysis and only 2 cases of dura injury resulting from UBEL. CONCLUSIONS: The UBEL method is a more useful technique than the MEL method as it requires a smaller bone resection area and produces fewer complications.

A screw position change at an early postoperative stage preceding the subsequent occurrence of screw loosening.

PURPOSE: The authors recently proposed the novel radiologic assessment method to measure chronological screw position changes precisely. The aim of this study was to predict the late occurrence of screw loosening, which was diagnosed by the radiographic lucent zone, by evaluating screw position changes at an early postoperative stage using the novel method. METHODS: Forty-three patients who underwent thoracolumbar screw fixation and follow-up computed tomography (CT) scans on the day, between 1 and 5 weeks, and at more than 6 months after surgery were retrospectively evaluated. Screw images were generated from CT data. Screw position changes were evaluated by superposing screw images on the day and between 1 and 5 weeks after surgery. Screw loosening was diagnosed by the radiographic lucent zone on CT images at 6 months or later post-surgery, and patients were classified into screw loosening and non-loosening groups. The early screw position changes were compared between the two groups. RESULTS: Significant differences in early screw position changes were found between the screw loosening and non-loosening groups in Mann-Whitney U test (p = 0.001). On the receiver operating characteristic (ROC) curve analysis, the area under the ROC curve was 0.791, and the best cutoff value of early screw position change for the prediction of screw loosening was 0.83 mm with a sensitivity of 64.0% and a specificity of 88.9%. CONCLUSION: We calculated a cutoff value of the screw position changes at an early postoperative stage for the prediction of subsequent development of screw loosening with the radiographic lucent zone.

Postoperative Outcomes After Transsacral Epiduroscopic Laser Decompression in Japanese Patients: Denervation Therapy for Discogenic Low-Back Pain.

Background: Transsacral epiduroscopic laser decompression (SELD) is a very noninvasive surgery, so it is effective for elderly patients and athletes and is a new and minimally invasive therapeutic technique that may be useful in many patients with discogenic low-back pain (LBP) having high signal intensity zone (HIZ) in magnetic resonance imaging (MRI). We investigated the clinical outcomes of SELD in Japanese patients with discogenic LBP having HIZ as a first trial. Methods: The subjects consisted of 52 patients who underwent SELD and were followed up for at least 6 months. All patients with LBP with HIZ were operative using the SELD technique. Outcomes of the patients were assessed with visual analogue scale (VAS) for LBP, the Oswestry disability index (ODI), and the EuroQol 5 dimension (EQ-5D). Statistical analyses were carried out using a paired t-test. A p-value of <0.05 was considered significant. For statistical analysis, we used the SPSS software program. Results: At 12 months after the procedure, the average VAS score for LBP fell to 1.2 from 5.6 (p-value <0.05). The ODI score also dropped from the preoperative level of 22.3 to 8.8. The EQ-5D score also significantly increased from the preoperative level of 0.865 (SD 0.10) to 0.950 (SD 0.05). Eight cases of intraoperative cervical pain were observed as complications with no cases of hematomas, infections, and postoperative neurosis was observed. Conclusions: SELD provides a novel minimally invasive technique capable of performing multilevel intervertebral surgery. We believe that SELD is an effective method of treating discogenic LBP due to HIZs.

Dysphagia following C1 laminectomy and posterior atlantoaxial fixation for retro-odontoid pseudotumor: a case report.

Purpose: Although dysphagia is known potential complication of cervical spine surgery, it rarely occurs after a posterior approach. We describe an unusual case of a retro-odontoid pseudotumor that suffered dysphagia following a C1 laminectomy and posterior atlantoaxial fixation.Materials and methods: A 79-year-old man presented with progressive tetraparesis and bladder and bowel dysfunction due to severe compression to cervical cord at C1 from a retro-odontoid pseudotumor. After C1 laminectomy and atlantoaxial fixation, the symptoms improved, but dysphagia and aspiration developed, associated with pharyngeal and esophageal stases on videofluoroscopy.Results and conclusions: Possible explanations for postoperative dysphagia include limitation of cervical spine motion, and cervical cord reperfusion injury in addition to the baseline anterior osteophyte and aging. This is the first case of dysphagia developing after laminectomy and posterior atlantoaxial fixation not involving the occipital bone.

A Novel Radiologic Assessment of Screw Loosening Focusing on Spatial Position Change of Screws Using an Iterative Closest Point Algorithm with Stereolithography Data: Technical Note.

OBJECTIVE: In thoracolumbar spinal instrumentation surgery, pedicle screw fixation is widely used, whereas screw loosening occurs only occasionally over time. It is common to evaluate screw loosening by the radiographic lucent zone around screws, which can neither evaluate loosening quantitatively nor detect slight screw loosening. In the present technical note, we describe a novel assessment technique of screw loosening by generating 3-dimensional screw images from computed tomography data and superposing them in time series. METHODS: Computed tomography data were exported in digital imaging and communications in medicine dataset and imported to the 3-dimensional computer-aided designing software, by which screws and rods were segmented and outputted in stereolithography (STL) format. The STL files were imported to the software, and registration based on iterative closest point algorithm was performed to assess screw position changes. RESULTS: Positional changes on STL in time series were classified into 3 types: 1) no position changes existed in the entire system of screws and rods; 2) position changes existed in the entire system of screws and rods, but no position changes were shown when the left-sided and right-sided screws and rod were separately evaluated; and 3) position changes existed in the left and/or right-sided screws and rods even when evaluated separately. CONCLUSIONS: This technique enables the quantitative evaluation of screw loosening and loosening between screws and rods. In conjunction with conventional methods of assessing radiographic lucent zone, we are able to obtain more accurate information regarding screw loosening after spinal instrumentation surgery.

[Investigation of Repeatability of Residual Urine Volume Measurement for Lower Urinary Tract Disorder in Patients with Lumbar Degenerative Disorders].

STUDY DESIGN: prospective study OBJECTIVE:To evaluate repeatability of residual urine(RU)volume measurement(RUM)in patients with lumbar degenerative disorders. SUMMARY OF BACKGROUND DATA: RUM by abdominal echo is a non-invasive modality to evaluate lower urinary tract disorder(LUTD), repeatability of which is not found in urological disorders. Additionally, its repeatability has not been confirmed in spinal disorders. The authors examined repeatability of RUM for evaluation of LUTD in patients with lumbar degenerative disorders. METHODS: Thirty-four patients with lumbar degenerative disorders and 7 normal adult volunteers entered our study. RUM was performed at least twice(two to seven times; average 3.6 times). According to urological guidelines, RU over 50 cc is defined as abnormal. Thirty-four patients were divided into two groups:the U+group with lower urinary tract lesion(16 patients)and the U-group without such a lesion(18 patients). RESULTS: In normal adult volunteers:In all volunteers, there was no abnormal RU. Repeatability of RUM was 100%. Average RU volume was 1.6 cc. In patients with lumbar degenerative disorders:Repeatability of RUM was 94.4% in the U-group(average RU volume was 35.2 cc)and 50% in the U+group(average RU volume was 50.1 cc). In all patients with lumbar degenerative disorders, repeatability of RUM was 73.5%(average RU volume was 43.0 cc). CONCLUSIONS: Repeatability of RUM in patients with lumbar degenerative disorders was 73.5%. Especially, in patients without lower urinary tract lesion, high repeatability of RUM was confirmed. According to the present study, RUM seemed to be a dependable modality to evaluate LUTD in patients with lumbar degenerative disorders.

[Distribution of Pain and Numbness in Patients with Cervical Spine Disorders].

PURPOSE: To elucidate the distribution of improved pain and numbness after cervical decompression surgery in patients with cervical spine disorders. METHODS: This study included 4 men and 5 women aged 45 to 71 years(mean 58 years)presenting with radiculopathy and 50 men and 17 women aged 35 to 88 years(mean 66 years)presenting with myelopathy. RESULTS: All 9 patients with radiculopathy presented with neck pain, and 3 presented with cervical angina. Among the patients with myelopathy, 2 presented with headache, 2 with onion-skin facial pain, 29 with neck pain, 8 with truncal pain, 7 with low back pain, 4 with numbness below the T4 dermatomal area, 1 with penile pain, 61 with arm pain, 49 with leg pain, and 2 without pain or numbness. Patients with myelopathy presenting with preoperative neck and arm pain had significantly better recovery rates compared to patients without such pain. CONCLUSION: Patients with cervical spine disorders present with pain and numbness in various areas. Preoperative neck pain and arm pain are indicators for better recovery in patients with myelopathy.

Onion-skin Hemifacial Dysesthesia Successfully Treated with C2-4 Anterior Cervical Decompression and Fusion: A Case Report.

A 49-year-old man with cervical spondylosis at the C2-4 level presented with onion-skin hemifacial dysesthesia in addition to the right extremities. C2-4 anterior cervical decompression and fusion were performed. Onion-skin hemifacial pain disappeared after surgery. Although we cannot conclude the etiology of the pain was either referred pain or direct injury to the spinal trigeminal nucleus, cervical spondylosis at the middle cervical level has a possibility to present facial pain.

Cervical ossification of posterior longitudinal ligament in x-linked hypophosphatemic rickets revealing homogeneously increased vertebral bone density.

There is no report that describes in detail the radiological and intraoperative findings of rickets with symptomatic cervical ossification of the posterior longitudinal ligament. Here, we describe a case of X-linked hypophosphatemic rickets with cervical ossification of the posterior longitudinal ligament presenting unique radiological and intraoperative findings. The patient presented progressive tetraparesis. Magnetic resonance imaging studies revealed severe cervical spinal cord compression caused by ossification of the posterior longitudinal ligament. Computed tomography scans revealed homogeneously increased vertebral bone density. An expansive laminoplasty was performed. At surgery, homogeneously hard lamina bone was burdened in drilling and opening of the laminae. The patient's neurological symptoms were improved postoperatively. Bony fusion of the hinges occurred postoperatively. Therefore, expansive laminoplasty could be performed for symptomatic cervical ossification of the posterior longitudinal ligament with X-linked hypophosphatemic rickets. However, unusual bone characters should be taken into consideration for careful operation during surgery.

Midline lumbar fusion with cortical bone trajectory screw.

A novel cortical bone trajectory (CBT) screw technique provides an alternative fixation technique for lumbar spine. Trajectory of CBT screw creates a caudo-cephalad path in sagittal plane and a medio-lateral path in axial plane, and engages cortical bone in the pedicle. The theoretical advantage is that it provides enhanced screw grip and interface strength. Midline lumbar fusion (MIDLF) is composed of posterior midline approach, microsurgical laminectomy, and CBT screw fixation. We adopted the MIDLF technique for lumbar spondylolisthesis. Advantages of this technique include that decompression and fusion are available in the same field, and it minimizes approach-related damages. To determine whether MIDLF with CBT screw is as effective as traditional approach and it is minimum invasive technique, we studied the clinical and radiological outcomes of MIDLF. Our results indicate that MIDLF is effective and minimum invasive technique. Evidence of effectiveness of MIDLF is that patients had good recovery score, and that CBT screw technique was safety in clinical and stable in radiological. MIDLF with CBT screw provides the surgeon with additional options for fixation. This technique is most likely to be useful for treating lumbar spondylolisthesis in combination with midline decompression and insertion of an interbody graft, such as the transforaminal lumbar interbody fusion or posterior lumbar interbody fusion techniques.

[Evaluation of micturitional disturbance in spinal disorders: reproducibility of uroflowmetry].

Patients with spinal degenerative diseases suffer not only neuropathy in the extremities but also lower urinary tract dysfunction(LUTD). Patients with cauda equina syndrome generally need emergency decompression to pelvic visceral function, especially that of the urinary bladder. However, less prominent voiding symptoms can be missed in clinical settings. There is a discrepancy between lower urinary tract symptoms and LUTD. Therefore, urodynamic studies are needed to screen of patients with spinal diseases. Cystometry and urethral sphincter electromyography are useful for increasing our understanding of LUTD but are too invasive for screening. Our protocol for the evaluation of LUTD consists of residual urine measurement and uroflowmetry(UFM). UFM is the simplest and noninvasive urodynamic technique;however, it has the disadvantage of being nonreproducible, which depends on bladder volume, diurnal variation, presence of obstructive disease, and mental stress. UFM was reportedly reproducible in normal individuals in 1979, but was not evaluated in patients with spinal disease. This study examined the reproducibility of UFM in patients with spinal disease. UFM was performed twice in 26 male patients with cervical or lumbar degenerative disease. Maximum urinary flow rate corrected with Siroky's nomogram was reproducible in 23(88.5%)of the 26 patients. A urinary flow curve was reproducible in 25(96.2%)of the 26 patients, and only 1 patient had excessive urination at the 1st UFM and normal urination at the 2nd UFM. The reproducibility of UFM was high in patients with spinal degenerative disease.

Symptomatic osteochondroma of lumbosacral spine: report of 5 cases.

We describe 5 cases of osteochondroma (OC) originating from lumbosacral spine which caused radiculopathy. Four cases originated from the lumbar spine; all from L4 inferior articular process and presented L5 radiculopathy, the other one case originated from the sacrum; the case from S1 superior articular process presented L5 radiculopathy. In all cases, definitive diagnosis was made with histopathological findings; typical cartilaginous capping was confirmed. The functional recovery was completed in all 5 cases. As for imaging study, post myelography computed tomography revealed the most diagnostic tool for understanding the relationship between nerve tissue and the tumor. In all 5 patients, the tumors contained a high signal intensity on T2-weighted images in the central medullary area. OCs are sometimes difficult to diagnose because they mimic other conditions like bony spur formation due to osteoarthritis, so we should never fail to confirm the histopathological diagnosis of such lesions when suspected.

[Study on the area of pain and numbness in cases with lumbosacral radiculopathy].

In the clinical diagnosis of lumbosacral radicular symptoms, dermatome maps are commonly used, by which the segmental location of the affected nerve can be determined. However, the diagnosis is often difficult because the pattern of sensory disturbance does not necessarily match the patterns of classical dermatomes, and there are many dermatome maps made by different methods. The author examined the area of pain and numbness in cases of lumbosacral radiculopathy. Clinical features of pain and numbness in consecutive seventy three cases of lumbosacral radiculopathy were investigated (L3: n=13, L4-S1: n=20). Patients of L3 radiculopathy showed symptoms at the upper buttock and ventral surface of the thighs, knees and upper ventral surface of the legs. Patients of L4 radiculopathy showed symptoms at the ventro-lateral surfaces of the thigh and leg. The distinctive region, defined as the region having 100% superimposition, of L4 radiculopathy was the lateral part of the shin. Patients of L5 radiculopathy showed symptoms at the lateral surfaces of the thigh and leg. The distinctive region was the upper buttock. Patients of S1 radiculopathy showed symptoms at the lower buttock, dorso-lateral part of the leg and lateral part of the foot. The distinctive region was the lateral part of the calf. It was found that the regions of pain and numbness formed a continuous band-like zone from thigh to leg in 8% of L3, 45% of L4 and L5, and 35% of S1 radiculopathy. Using a visual analogue scale, the degree of leg pain was more severe than low back pain in 68% of the patients, but in 5% of patients, low back pain was more severe.

Nontraumatic cervical disc herniation in a 21-year-old patient with no other underlying disease.

A 21-year-old woman presented with cervical myelopathy due to nontraumatic cervical disc herniation associated with cervical canal stenosis. The patient underwent removal of the herniated disc and anterior fusion with an autogenous iliac crest bone graft. After surgery, the patient showed satisfactory improvement. Cases of cervical disc herniation in our center and reported cases without cervical trauma in either young adults or in childhood were reviewed retrospectively. We discuss the pathogenesis of cervical disc herniation in our young patient in the context of these other cases. Cervical disc herniation rarely occurs before the age of 30 years. A history of cervical trauma and preexisting fusion of the cervical spine are risk factors for cervical disc herniation. The present case is the youngest known of nontraumatic disc herniation without other underlying disease. Hypermobility due to neck cracking and a relatively narrow spinal canal might have been important in causing cervical myelopathy by disc herniation.

Clinical outcomes and adverse events following transforaminal interbody fusion for lumbar degenerative spondylolisthesis in elderly patients.

Transforaminal lumbar interbody fusion (TLIF) procedure is widely used, but the surgical indications for TLIF in elderly patients remain controversial because of potential risks such as inferior bone quality and higher rate of postoperative complications. Clinical efficacy and operative risk of TLIF in elderly patients are unclear. This study investigated the clinical effect and safety of TLIF for lumbar degenerative spondylolisthesis with radiculopathy or neurogenic claudication in patients aged 70 years or older. The clinical records were retrospectively reviewed of 35 consecutive patients aged 70-86 years (mean 74.8 years) who underwent one or two-level TLIF. The preoperative diagnosis included degenerative spondylolisthesis with segmental instability. Clinical outcomes were assessed by the Japanese Orthopaedic Association score, visual analogue scale, Oswestry Disability Index. Radiological fusion rate was also investigated. Clinical and radiological results were compared with those of 43 younger patients. Clinical outcome measures were significantly improved after operation in the elderly patients, but improvement rates were significantly lower than those of younger patients. Fusion rate was similar in both groups. Overall postoperative complications were increased in aged patients, although the prevalence of complications directly related to surgical technique was not significantly increased. Postoperative complications not related to the surgical procedure were factors affecting poor results. TLIF is acceptable for achieving clinical recovery and lumbar fusion with high radiographic fusion success even in elderly patients, although clinical benefits were limited compared with those of younger patients. Postoperative morbidity was mainly related to general or non-operative site complications.

Lumbar discal cyst with spontaneous regression and subsequent occurrence of lumbar disc herniation.

A 39-year-old man presented with an extremely rare discal cyst at the L3-4 level manifesting as a left L4 radiculopathy. Two months after onset, he suffered right L4 radiculopathy with new lumbar disc protrusion. Five months after medical treatment, the patient's symptoms improved, and the discal cyst showed complete regression on magnetic resonance imaging. Most cases of discal cyst are surgically treated, with only two previous cases of spontaneous regression. The present case suggests clinical and radiological recovery of symptomatic lumbar discal cyst can be obtained by only conservative therapy.

Remarkable epidural scar formation compressing the cervical cord after osteoplastic laminoplasty with hydroxyapatite spacer.

The authors report on an 81-year-old woman whose condition deteriorated 2 months after undergoing osteoplastic laminoplasty with placement of hydroxyapatite spacers. Magnetic resonance imaging showed postlaminectomy scar formation compressing the cervical spinal cord. The patient underwent laminectomy and removal of remarkably thick epidural scar tissue, which resulted in resolution of her symptoms. Histological diagnosis of the scar was fibrous granulation tissue with foreign body granuloma, characterized by multinucleated giant cells and marked increases of capillary vessels, fibroblasts, and collagen fibers. This case of symptomatic postlaminectomy scar formation after osteoplastic laminoplasty suggests that osteoplastic laminoplasty cannot always prevent laminectomy membrane formation.

[Investigation of pseudolocalizing signs in the lumbar region: analysis of L5 monoradiculopathy due to upper lumbar compressive lesions].

BACKGROUND AND PURPOSE: Pseudolocalizing signs in lumbar spinal disease seems to be rarely encountered. To our knowledge, only six cases which caused L5 monoradiculopathy due to upper lumbar lesions have been described. We retrospectively reviewed patients with similar signs in our center, and we discussed the pathogenesis of such interesting neurological signs depending on our own and reported cases. RESULTS: Between January, 2005 and August, 2010, 1,229 patients with lumbar degenerative disease underwent spinal decompression surgery, 3 of which (0.24%) presented with L5 monoradiculopathy due to upper compressive lesions in lumbar spinal disease. DISCUSSION AND CONCLUSION: As pathological mechanisms, 2 hypotheses are speculated: Direct compression at the epiconus level or circulatory disturbance at the nerve root itself. If the level of the conus medullaris is situated at the lower lumbar level, such as L2 level, a compressive lesion at the L1-2 level, for example lumbar disc herniation, can compress the L5 nerve root resulting in L5 nerve palsy. However, the affected level below the cauda equina doesn't seem to compress only the L5 nerve root directly, because the cauda equina is mobile enough to avoid the compression. Another speculated mechanism is the so-called circulatory disturbance. When the cauda equina is remarkably compressed at the upper level, less severe compressive change may cause selective monoradiculopathy at the lower lumbar level. Based upon the presented analyses, we adopt the circulatory mechanism in our cases as the causative factor in lumbar pseudolocalizing signs.

Surgical outcome and postoperative work status of lumbar discogenic pain following transforaminal interbody fusion.

The clinical outcome and resumption of work were investigated in 21 patients with lumbar discogenic pain (15 males and 6 females, mean age 37.2 years), who failed to respond to intensive conservative therapy, treated by transforaminal lumbar interbody fusion (TLIF) augmented with the pedicle screw system from January 2005 to December 2007. Perioperative assessment was performed using the modified Japanese Orthopaedic Association (mJOA) score, the Oswestry Disability Index, and the visual analogue scale (VAS). Type of occupation and work status of the patients were also assessed before and after surgery. Preoperative occupation was divided into two groups according to the work content (heavy labor vs. light labor). Follow-up period was mean 26.1 months, and greater than 1 year in all patients. Perioperative assessment showed postoperative improvement with statistical significance. Recovery rates at final follow-up examination were 53% of the mJOA score and 65% of the VAS. This study showed that postoperative overall resumption rate was 90%. However, only 23% of the heavy labor group returned to the previous work compared with 71% of the light labor group. TLIF is thought to be a safe and effective technique in patients with intractable chronic lumbar discogenic pain with an acceptable overall work resumption rate, whereas complete return to previous jobs was limited in the heavy labor group.