Yuji Matsubara

Natural history of patients with lumbar disc herniation observed by magnetic resonance imaging for minimum 7 years.

Objective: The aim of this work was to elucidate the relation between the clinical course and morphologic changes of lumbar disc herniation on magnetic resonance imaging (MRI). Methods: Twenty-one patients with lumbar disc herniation treated nonsurgically were followed for a minimum of 7 years and investigated with regard to their clinical outcome and the initial, 2-year, and final stage MRI findings. The space-occupying ratio of herniation to the spinal canal and the degree of disc degeneration were evaluated on serial MRI. Results: The mean space-occupying ratio of herniation showed significant reduction both on the 2-year and on the final scans. Progression of degeneration of the intervertebral disc was seen in all patients at the final investigation. Comparing patients with and without symptoms, no factors were detected on the initial and 2-year MR images capable of distinguishing patients who were and were not destined to develop lumbago and/or sciatica in the future. Morphologic changes of lumbar disc herniation continued to occur even after 2 years. Conclusions: Clinical outcome did not depend on the size of herniation or the grade of degeneration of the intervertebral disc in the minimum 7-year follow-up.

Serial magnetic resonance imaging follow-up study of lumbar disc herniation conservatively treated for average 30 months: relation between reduction of herniation and degeneration of disc.

The natural history of lumbar disc herniation in conservatively treated patients is not entirely clear. This study was undertaken to clarify the relation between morphologic changes in the herniation and the clinical course. Serial magnetic resonance imaging studies were performed an average of 4.4 times in 30 patients in a 30-month-average period. The Japanese Orthopaedic Association (JOA) score and straight leg raising (SLR) test were improved, with the average reduction ratio of the herniation 15 and 18% on the sagittal and axial images, respectively. The JOA score and SLR test showed the most improvement within 1 year, with little change noted thereafter. In contrast, the disc herniation continued to reduce not only within 1 year, but also thereafter. Patients with progression of disc degeneration showed more marked regression of herniation than those in whom progression was not observed.

Preventive effect of artificial ligamentous stabilization on the upper adjacent segment impairment following posterior lumbar interbody fusion.

Study Design. A retrospective, comparative study. Objective. To assess the effects of soft stabilization with artificial ligamentous bands placed on the upper segment adjacent to posterior lumbar interbody fusion (PLIF) for prevention of transition syndrome compared with patients who underwent PLIF without soft stabilization. Summary of Background Data. Spine fusion increases mechanical stress and can cause other spinal problems adjacent to the fusion level. Soft stabilization using artificial ligamentous bands has been reported to decrease the flexion instability and this iatrogenic problems. There is no report concerning the effect of soft stabilization to transition syndrome following PLIF. Methods. In 225 patients undergoing L4/5 PLIF, 70 consecutive patients who were treated concomitantly with decompression of L3/4 with minimum 2-year follow-up were included. Thirty-five patients underwent soft stabilization of L3/4 (soft stabilization [S] group) with natural neutral concept rods, and 35 patients did not (decompression [D] group). Radiographic changes in the disc height, vertebral slip, intervertebral angle, range of motion, lumbar lordosis, and L3 tilt angle were measured. On magnetic resonance imaging (MRI), postoperative progression of the disc degeneration and spinal canal stenosis were evaluated. Results. In the S group, significant posterior intervertebral expansion on radiograph was less advanced at the final follow-up (P < 0.005). MRI images demonstrated less significant aggravation of disc degeneration (P < 0.001) and progression of adjacent stenosis (P < 0.01), at L3/4 in the S group. Adjacent intervertebral changes on MRI occurred relatively early after surgery, suggesting that changes were due to transition syndrome, but not age-related changes. Conclusion. These results demonstrated an effect of soft stabilization for the prevention of transition syndrome in lumbar spine fusion. Although the postoperative follow-up periods in this study were not sufficiently long to reach a definitive conclusion, intervertebral breakdown adjacent to the rigid spine fusion could be diminished by the application of soft stabilization.

Predictive factors for a poor surgical outcome with thoracic ossification of the ligamentum flavum by multivariate analysis: a multicenter study.

Study Design. Retrospective multi-institutional study. Objective. The purpose of this study was to describe the surgical outcomes in patients with ossification of the ligamentum flavum (OLF) and determine the influence of an ossified anterior longitudinal ligament (OALL) on the clinical features and surgical outcomes in thoracic OLF. Summary of Background Data. Detailed analyses of surgical outcomes of thoracic OLF have been difficult because of rarity of this disease. Methods. We identified 96 patients (77 males and 19 females with a mean age at surgery of 63.4 ± 10.3 yr) who underwent surgery for thoracic OLF and investigated their preoperative symptoms, severity of symptoms and myelopathy, disease duration, magnetic resonance imaging and computed tomographic findings, surgical procedure, intraoperative findings, and postoperative recoveries. The presence of OALL found at or near the most severely affected OLF level on sagittal computed tomographic images was classified into 1 of the following 4 types: (1) “no discernible type” (type N); (2) “one-sided type” (type O); (3) “discontinuous type” (type D); and (4) “continuous type” (type C). Multivariate logistic regression analysis was used to compute odds ratios and 95% confidence intervals to identify the risk factors associated with surgical outcomes. Results. The mean Japanese Orthopaedic Association score was 5.6 points preoperatively and 7.8 points 2 years postoperatively, yielding a mean recovery rate of 44.6%. Disease duration, presence of ossified dura mater, and type D OALL were the important factors for predicting surgical outcomes. Conclusion. After evaluating surgical outcomes on the largest sample size of OLF surgical procedures thus far, our results show that disease duration, ossification of the dura mater, and the presence of type D OALL were risk factors related to surgical outcomes. Level of Evidence: 3

Radiographic Adjacent Segment Degeneration at Five Years After L4/5 Posterior Lumbar Interbody Fusion With Pedicle Screw Instrumentation: Evaluation by Computed Tomography and Annual Screening With Magnetic Resonance Imaging.

Study Design:Retrospective clinical study. Objective:To investigate adjacent segment degeneration (ASD) at 5 years after L4/5 posterior lumbar interbody fusion with pedicle screw instrumentation and L4/5 decompression surgery using plain radiographs, computed tomography (CT), and magnetic resonance imaging (MRI), with the evaluation of annual changes on MRI. Summary of Background Data:Methods of evaluation have been inconsistent among studies of ASD. There is no report that ASD in the lumbar spine after posterior lumbar interbody fusion at the same level is thoroughly evaluated on radiographs, CT, annual MRI changes, and the impact of decompression procedures. Methods:ASD was evaluated in 52 patients. Disk height, vertebral slip, intervertebral angle, and intervertebral range of motion were examined on plain radiographs. Facet joint degeneration on CT and disk degradation and spinal stenosis on MRI were classified into categories, and facet sagittalization and tropism were measured on CT. The incidence of ASD was compared between the decompression procedures. Results:The radiographic changes observed in the study were defined as radiographic ASD (R-ASD) without reoperation, as no patient required reoperation. R-ASD was rarely detected by radiography. The incidences of facet joint degeneration, MRI-detected disk degeneration, and spinal stenosis at the L3/4 and L5/S1 levels were 21% and 23%, 27% and 17%, and 35% and 4%, respectively. Progressive disk degeneration at L3/4 was found significantly more frequently in patients with aggravation of facet degeneration (P<0.01); however, the severities of preoperative facet degeneration, facet sagittalization, and tropism were not associated with progressive disk degeneration or spinal stenosis. In annual MRI, most R-ASD cases were detected within 3 years after surgery. Patients who underwent L4 total laminectomy had significantly more frequent R-ASD compared with those who received bilateral fenestration at L4/5 (P<0.01). Conclusions:R-ASD was detected more frequently by CT and MRI compared with radiography. Preoperative facet joint degeneration and morphology were not always related to progressive disk degeneration or spinal stenosis. Annual MRI suggested that accelerated degeneration was due to lumbar spine fusion, rather than aging degeneration. Decompression with preservation of posterior connective components is recommended to prevent R-ASD.

An Arterial Pulse Examination Is Not Sufficient for Diagnosis of Peripheral Arterial Disease in Lumbar Spinal Canal Stenosis : A Prospective Multicenter Study

Study Design. Prospective, multicenter study. Objective. To conduct peripheral arterial disease (PAD) screening on intermittent claudication (IC) in patients with lumbar spinal canal stenosis (LSCS) to examine the relationships among combined LSCS and PAD, symptoms, and physical findings. Summary of Background Data. IC occurs due to two underlying diseases, LSCS and PAD, and has an increasing prevalence with the aging of society. Reliable diagnosis of PAD is critical for appropriate conservative management of IC patients with LSCS in an Orthopedic Surgery Outpatient Department (OSOPD). Methods. PAD tests were prospectively conducted in 201 patients with IC and LSCS who initially visited an OSOPD at a hospital affiliated with the Nogoya Spine Group. Occurrence of PAD as a complication was assessed using ankle brachial pressure index (ABI) and toe brachial pressure index (TBI) tests. PAD was diagnosed in patients with ABI ⩽ 0.9 or TBI ⩽ 0.6, and the relationship of the occurrence of PAD with symptoms and physical findings such as abnormal arterial pulses was investigated. Results. Combined LSCS and PAD was found in 52 patients (26%), with 45 cases (22%) diagnosed on the basis of TBI test in patients with a normal ABI. Of the patients with PAD, many suffered from risk factors for PAD, with a significantly higher frequency of PAD in patients with hyperlipidemia (P < 0.05). PAD also occurred significantly more frequently in patients with abnormal pulses in the popliteal (P < 0.05), posterior tibial (P < 0.0001), and dorsal pedis (P < 0.0001) arteries; however, the sensitivity of these tests for PAD diagnosis was relatively low, at 34%, 60% and 68%, respectively. Conclusion. The results of the prospective study define the rate of occurrence of combined LSCS and PAD using ABI and TBI tests for the first time, and the findings suggest that screening for PAD should be conducted in LSCS patients. ABI and TBI tests are necessary for PAD screening in outpatients, whereas observation of the arterial pulse in the lower extremities is necessary but not sufficient for PAD diagnosis.

Intradural disc herniation: Radiographic findings and surgical results with a literature review

OBJECTIVE To report a series of four cases of intradural disc herniation (IDH) with a review of the literature. SUMMARY OF BACKGROUND DATA IDH is a rare type of disc herniation. Preoperative diagnosis is difficult and IDH is only confirmed during surgery in most cases. Here, we describe four cases of IDH, including three with lumbar hernia and one with thoracic hernia. METHODS A retrospective chart review, surgical database query, and review of radiology reports are presented for each case, along with a literature review of IDH. RESULTS Two of the four patients had a history of surgery at the same spinal level. Ring enhancement in gadolinium-enhanced MRI, an air image in computed tomography, and complete block in myelography were observed in the series. Surgery was performed with a transdural approach in all patients. One patient underwent transforaminal lumbar interbody fusion after postoperative recurrence. Three patients with lumbar involvement had nerve root symptoms preoperatively, but showed symptomatic improvement in the early postoperative period. In contrast, the patient with thoracic involvement had preoperative muscle weakness due to myelopathy symptoms, and had residual symptoms after surgery. CONCLUSIONS IDH is a rare disease and characteristic imaging findings can be useful for diagnosis. Intraoperative findings lead to a definitive diagnosis in many cases and recognition of the pathological characteristics of IDH is important.

Postoperative Complications Associated With Spine Surgery in Patients Older Than 90 Years: A Multicenter Retrospective Study

Study Design: A review of a prospective database. Objectives: Surgery for elderly patients is increasing yearly due to aging of society and the desire for higher quality of life. The goal of the study was to examine perioperative complications in spine surgery in such patients. Methods: A multicenter study of surgical details and perioperative complications was performed in 35 patients aged older than 90 years who underwent spinal surgery, based on a review of a prospective database. The frequency and severity of complications were assessed, and the effects of patient-specific and surgical factors were examined. Major complications were defined as those that were life threatening, required reoperation in the perioperative period or left a permanent injury. Ambulatory function before and after surgery was also analyzed. Results: Perioperative complications occurred in 19 of the 35 cases (54%), and included 11 cases of postoperative delirium, most of which occurred after cervical spine surgery. There were 8 major complications (23%), including cerebral infarction (n = 3), coronary heart disease (n = 3), pulmonary embolism (n = 1), and angina (n = 1). Preoperative motor deficit, operative time, estimated blood loss, and instrumented fusion were significantly associated with major complications. An improved postoperative ambulatory status occurred in 61% of cases, with no change in 33%, and worsening in 2 cases (6%). Conclusions: Timing of surgery before paralysis progression and reduced surgical invasiveness are important considerations in treatment of the very elderly. Improved outcomes can be obtained with better management of spine surgery for patients aged 90 years or older.

Predictors of Prolonged Length of Stay After Lumbar Interbody Fusion: A Multicenter Study

Study Design: Retrospective analysis of a prospectively database. Objectives: To identify factors associated with prolonged length of stay (LOS) in posterior /transforaminal lumbar interbody fusion (PLIF/TLIF). Methods: The subjects were patients who underwent PLIF/TLIF at 10 facilities from 2012 to 2014. A total of 1168 such patients with a mean age of 65.9 ± 12.5 years (range 18-87 years) were identified in the database. Operations were PLIF (n = 675), TLIF (n = 443), minimally invasive surgery (MIS)-PLIF (n = 22), and MIS-TLIF (n = 32). Age, gender, body mass index, ambulatory status, comorbidities, perioperative American Society of Anesthesiologists (ASA) grade, operative factors, and complications were examined. LOS was defined as the number of calendar days from the operation to hospital discharge. LOS was categorized as normal (<75th percentile) or prolonged (≥75th percentile). Results: The average LOS was 20.8 ± 9.8 days (range 7-77 days). There was a significant correlation between LOS and age (P < .05). Reoperation during hospitalization was performed in 20 cases for surgical site infection (n = 12), epidural hematoma (n = 5), and screw misplacement (n = 3). In multivariate analysis, prolonged LOS was associated with preoperative variables of age ≥70 years (odds ratio [OR] 1.87, 95% CI 1.38-2.54), and ASA class ≥III (OR 1.52, 95% CI 1.04-2.25); surgical variables of open procedures (OR 5.84, 95% CI 1.74-19.63), fused levels ≥3 (OR 5.17, 95% CI 3.17-8.43), operative time ≥300 minutes (OR 1.88, 95% CI 1.15-3.07), and estimated blood loss ≥500 mL (OR 1.71, 95% 1.07-2.75). Conclusions: The factors identified in this study should help with obtaining informed consent, surgical planning and complication prevention to reduce health care costs associated with prolonged LOS.

Improvement of atelectasis after corrective fusion for lordoscoliosis with intrathoracic vertebral protrusion in arthrogryposis multiplex congenita: efficacy of positive-pressure ventilation test

Preoperative respiratory complications of spinal deformity are common, and many cases have restrictive ventilatory impairment associated with thoracic deformity accompanying spinal deformity [1]. In surgery performed for idiopathic scoliosis with restrictive ventilatory impairment, the thorax is expanded by correction of the spinal deformity alone, and respiratory function is improved after surgery [2]. However, in syndromic scolioses such as arthrogryposis multiplex congenita (AMC), development of thoracic lordoscoliosis may cause another respiratory disorder. Global lordotic deformity substantially decreases the thoracic AP diameter and impairs the rib dynamics, resulting in greater disturbance of respiratory function [3]. Cases with respiratory disorder caused by compression of the bronchus by lordoscoliosis-induced anterior protrusion of the vertebral body have also been reported [4, 5]. In the largest series reported to date, Dubousset [3] described the pathological conditions of 18 cases (16 surgical cases) in which thoracic spinal deformity-induced intrathoracic vertebral protrusion compressed the bronchus and caused respiratory disorder. All patients with preoperative atelectasis were treated with anterior vertebral body resection to remove compression on the bronchus, followed by posterior fusion for scoliosis, and lobectomy was additionally performed in two cases. However, it is unclear if all cases of lordoscoliosis accompanied by atelectasis require vertebral body resection and lobectomy. We experienced a patient with AMC complicated by atelectasis caused by compression of the bronchus by lordoscoliosis in whom correction of the spinal deformity without vertebral body resection and lobectomy was performed based on the improvement of atelectasis during intraoperative positivepressure ventilation. Atelectasis and respiratory function were improved after surgery. There has been no previous case report of AMC complicated by lordoscoliosis-associated atelectasis in which atelectasis was improved by correction of spinal deformity alone. We also discuss the value of improving atelectasis during positive-pressure ventilation as a treatment indicator. Consent for publication was obtained from the patient’s parents.