Prognosis and adjacent segment disease after lumbar spinal fusion surgery for destructive spondyloarthropathy in long-term hemodialysis patients.

BACKGROUND: Lumbar destructive spondyloarthropathy (DSA) is a serious complication in long-term hemodialysis patients. There have not been many reports regarding the surgical management for lumbar DSA. In addition, the adjacent segment pathology after lumbar fusion surgery for DSA is unclear. The objective of this study was to assess the clinical outcome and occurrence of adjacent segmental disease (ASD) after lumbar instrumented fusion surgery for DSA in long-term hemodialysis patients. MATERIALS AND METHODS: A consecutive series of 36 long-term hemodialysis patients who underwent lumbar instrumented fusion surgery for DSA were included in this study. The mean age at surgery was 65 years. The mean follow-up period was 4 years. Symptomatic ASD was defined as symptomatic spinal stenosis or back pain with radiographic ASD. The Japanese Orthopedic Association score (JOA score), recovery rate (Hirabayashi method), complications, and reoperation were reviewed. RESULTS: The mean JOA score significantly increased from 13.5 before surgery to 21.3 at the final follow-up. The mean recovery rate was 51.4%. Six of the 36 patients died within 1 year after index surgery. One patient died due to perioperative complication. Symptomatic ASD occurred in 43% (13 of 30) of the cases. Of these 13 cases, 5 had adjacent segment disc degeneration and 8 had adjacent segment spinal stenosis. Three cases (10%) required reoperation due to proximal ASD. Multi-level fusion surgery increased the risk of ASD compared with single-level fusion surgery (59% vs. 23%). The recovery rate was significantly lower in the ASD group than the non-ASD group (38% vs. 61%). DISCUSSION: This study demonstrated that symptomatic ASD occurred in 43% of patients after surgery for lumbar DSA. A high mortality rate and complication rate were observed in long-term hemodialysis patients. Therefore, care should be taken for preoperative planning for surgical management of DSA.

Erosion in the occipital bone caused by the fixation instrument used for posterior atlantoaxial fusion -report of 4 cases.

INTRODUCTION: Conventionally, posterior C1-C2 fusion has been performed using a sublaminar wiring technique with a structural bone graft. Subsequent advent of newer fixation devices, such as the C1 lateral mass screw and C1 hook, has achieved more solid fixation with improved surgical outcome; however, in these fixation systems, the protruding end of the metal implant above the level of the atlas may result in a complication due to contact with the surrounding structures. CASE DESCRIPTION: Two men and two women whose ages at the time of surgery ranged from 14 to 72 years. A supralaminar hook was used as a fixation device for C1 in two cases, whereas a lateral mass screw (Tan's method) and an atlas claw hook were employed for one each of the remaining 2 cases. We retrospectively reviewed the clinical features and postoperative course of these patients using the clinical records. Moreover, we measured the protruding height of the instrument above the atlas as well as the Redlund-Johnell (R-J) value on postoperative radiographs. All patients complained of crepitus and/or pain on neck extension. Erosion in the occipital bone was detected on multiplanar reconstruction computed tomography (MPR-CT), whereas plain radiographs failed to reveal the bony change. In those cases, protruding instruments used for C1 fixation contacted the occipital bone resulting in an erosive change at the impingement point. We removed the implant in all four cases after confirmation of solid bony union. DISCUSSION AND EVALUATION: Two of the four patients complained of occipital crepitus alone without pain. The management options for this condition may be controversial; however, progression of bony erosion may result in perforation of the occipital bone. This may possibly be associated with the serious complication of cerebrospinal fluid leakage. Considering this potential sequela, we removed the implants from all our reported cases after confirmation of solid bony union. CONCLUSIONS: We treated four cases that developed erosion in the occipital bone after posterior spinal instrumentation was performed for upper cervical lesions including C1. MPR-CT was useful in detecting the erosive changes in the occipital bone.

The impact of dynamic factors on surgical outcomes after double-door laminoplasty for ossification of the posterior longitudinal ligament of the cervical spine.

OBJECT: Laminoplasty is the preferred operation for most patients with cervical myelopathy due to multilevel ossification of the posterior longitudinal ligament (OPLL). Recent studies have demonstrated several significant risk factors for poor clinical outcomes after laminoplasty, including older age, lower preoperative Japanese Orthopaedic Association (JOA) score, postoperative change in cervical alignment, cervical kyphosis, and high occupying ratio of the OPLL (that is, the ratio of the greatest anteroposterior thickness of the OPLL to the anteroposterior diameter of the spinal canal at the same level on a lateral image). However, the impact of dynamic factors on clinical outcomes is unclear. The purpose of this study is to assess the impact of dynamic factors on the clinical outcome after laminoplasty for cervical myelopathy due to OPLL. METHODS: A consecutive series of patients who underwent laminoplasty for cervical myelopathy due to OPLL between 2003 and 2009 was retrospectively reviewed. The indication for laminoplasty at the authors' hospital included preoperative straight or lordotic alignment of the cervical spine and an occupying ratio of OPLL less than 60%. The JOA score and recovery rate were used to evaluate clinical outcomes. A poor clinical outcome was defined as a recovery rate of less than 50%. Patient factors examined along with outcome included age, preoperative JOA score, preoperative somatosensory evoked potentials, preoperative motor evoked potentials, body mass index, and presence of high intensity on MRI. Radiographic measures included the preoperative C2-7 lordotic angle, preoperative C2-7 range of motion (ROM), preoperative segmental ROM at the level of myelopathy, and the occupying ratio of OPLL. RESULTS: There were 45 patients (33 males and 12 females). The mean follow-up period was 4 years (range 2-6.8 years). The mean patient age was 66.9 years (range 50-85 years). The mean JOA score significantly increased from 9.1 before surgery to 13.1 at the final follow-up. The mean recovery rate was 51.2%. Nineteen patients (42%) had a recovery rate of less than 50%. Patient factors were not associated with surgical outcomes. Only the preoperative C2-7 ROM was significantly greater in the poor surgical outcome group (23.1° vs 14.1°). Receiver operating characteristic curve analysis showed that the optimal preoperative C2-7 ROM cutoff was 20°. Logistic regression analysis revealed that patients with a preoperative C2-7 ROM of greater than 20° had a 4.6 times higher risk (p = 0.021) of a poor clinical outcome, indicating that dynamic factors may have an impact on the surgical outcome of laminoplasty. CONCLUSIONS: Fusion surgery may be a useful strategy in patients with preoperative hypermobility of the cervical spine.

Subarachnoid-subarachnoid bypass for spinal adhesive arachnoiditis.

The authors report a case of adhesive arachnoiditis (AA) and arachnoid cyst successfully treated by subarachnoid to subarachnoid bypass (S-S bypass). Arachnoid cysts or syringes sometimes compress the spinal cord and cause compressive myelopathy that requires surgical treatment. However, surgical treatment for AA is challenging. A 57-year-old woman developed leg pain and gait disturbance. A dorsal arachnoid cyst compressed the spinal cord at T7-9, the spinal cord was swollen, and a small syrinx was present at T9-10. An S-S bypass was performed from T6-7 to T11-12. The patient's gait disturbance resolved immediately after surgery. Two years later, a small arachnoid cyst developed. However, there was no neurological deterioration. The myelopathy associated with thoracic spinal AA, subarachnoid cyst, and syrinx improved after S-S bypass.

Therapeutic impact of organism isolation in management of patients with pyogenic vertebral osteomyelitis.

In management of patients with pyogenic vertebral osteomyelitis, organism isolation by biopsy is generally considered to be of primary importance when constructing a treatment plan. In our clinical practice, however, patients can be successfully treated even without identifying the organisms. The objective of this study is to review our clinical experiences and clarify the therapeutic impact of organism isolation. Forty patients who were conservatively managed in our institution constituted the base of this study. The average follow-up period was 16.7 months. Among the study subjects, 13 patients underwent percutaneous needle biopsy and the organism was identified in 6 patients. Additionally, the organism was isolated from the sample obtained from blood and possible foci in 10 patients. In total, the causative organism was identified in 15 of the 40 patients (37.5%). Patients were divided into two groups based on whether the organism was identified by culture (Groups A and B, with and without organism isolation respectively). The duration of antibiotic therapy was not significantly different between the groups (Group A: 4.8 ± 1.6 months, Group B: 4.3 ± 2.1 months), while subsequent mortalities in Group A and B were 13.3% and 8% without significant intergroup difference. Organism isolation did not productively help select the effective antibiotics and reduce the treatment period or mortality rate in treatment of patients with pyogenic vertebral osteomyelitis. Therefore, current strategic antibiotic therapy may be effective in eradicating infection even without identification of the causative organism in treatment of patients with pyogenic vertebral osteomyelitis.

Risk factors for intraoperative lateral mass fracture of lateral mass screw fixation in the subaxial cervical spine.

OBJECT: Although lateral mass screw fixation for the cervical spine is a safe technique, lateral mass fracture during screw fixation is occasionally encountered intraoperatively. This event is regarded as a minor complication; however, it poses difficulties in management that may affect fixation stability and clinical outcome. The purpose of this study is to determine the incidence and etiology of lateral mass fractures during cervical lateral mass screw fixation. METHODS: A retrospective clinical review of patient records was performed in 117 consecutive patients (mean age 57 years, range 15-86 years) who underwent lateral mass screw fixation using a modified Magerl method from 1997 to 2010 at a single institution. A total of 555 lateral masses were included in this study. The outer diameters of the screws were 3.5 or 4.0 mm. In the retrospective clinical analysis, the incidence of intraoperative lateral mass fractures was reviewed. Potential risk factors for this complication were assessed using multivariate analysis. RESULTS: The incidence of lateral mass fractures during cervical lateral mass screw fixation was 4.7% (26 lateral masses) among all cases. Among the disorders, the incidence was highest in patients with destructive spondyloarthropathy (DSA) (18.8%, 12 lateral masses). There was no significant difference with respect to lateral mass fracture between the use of 4.0-mm screws (5.6%) and 3.5-mm screws (3.6%). Independent risk factors identified by logistic regression were DSA (OR 7.89, p < 0.001) and screw insertion in the C-6 lateral masses (OR 2.80, p = 0.018). CONCLUSIONS: The overall incidence of lateral mass fracture during cervical lateral mass screw fixation was 4.7%. Destructive spondyloarthropathy as an underlying cause of morbidity and screw placement in the C-6 lateral mass were identified as independent risk factors. Use of a 4.0-mm screw in patients with DSA may be a principal risk factor for this complication.

C-5 palsy after cervical laminoplasty with instrumented posterior fusion.

OBJECT: Postoperative C-5 palsy is known as a common complication after cervical laminoplasty. The authors of this article have encountered postoperative C-5 palsy more often when laminoplasty was combined with instrumented posterior spinal fusion than when it was performed alone. The purpose of this clinical study was to examine the incidence of fifth cervical nerve root palsy (C-5 palsy) and surgical results in patients with cervical myelopathy who had undergone laminoplasty with or without instrumented spinal fusion. METHODS: The authors retrospectively studied patients with cervical myelopathy who had undergone laminoplasty with or without instrumented posterior spinal fusion. RESULTS: Clinical data on 58 patients were evaluated and analyzed. Preoperative diagnoses were cervical spondylotic myelopathy or ossification of the posterior longitudinal ligament of the cervical spine. Twenty-four patients with spondylolisthesis or kyphosis underwent laminoplasty combined with posterior spinal fusion using instrumented lateral mass fixation (fusion group), while the remaining 34 patients underwent laminoplasty without posterior spinal fusion (no-fusion group). In the fusion group, C-5 palsy developed in 6 patients; in the no-fusion group, it occurred in only 1 patient. There was a significant difference in the rate of this complication between the 2 groups. In the fusion group, local kyphosis and spondylolisthesis level were reduced at the fusion level, and all patients with C-5 palsy underwent C4-5 spinal fusion. CONCLUSIONS: The incidence of postoperative C-5 palsy is significantly higher after laminoplasty when it is combined with spinal fusion. Correction of kyphosis and spondylolisthesis using posterior instrumentation may be a risk factor for iatrogenic intervertebral foraminal stenosis leading to C-5 palsy.

Postoperative spinal cord herniation with pseudomeningocele in the cervical spine: a case report.

BACKGROUND CONTEXT: Postoperative spinal cord herniation with pseudomeningocele is a rare disease, with only five cases reported before the present study. PURPOSE: To describe the clinical features and radiologic findings of postoperative spinal cord herniation with pseudomeningocele. STUDY DESIGN: Case report. METHODS: A case of a 51-year-old man who suffered from postoperative spinal cord herniation with pseudomeningocele was reported, and previous reports on this subject are reviewed. RESULTS: He had undergone excision of a spinal cord tumor in the cervical spine 10 years previously. He had progressive paraparesis and urinary disturbance 10 years later. The Computed Tomography Multi Planner Reconstruction myelogram showed dilation of the ventral subarachnoid space with left deviation of the spinal cord into the pseudomeningocele at C7. On observation at surgery, the spinal cord appeared displaced dorsally and herniated through the defect of the dorsal dura mater. The spinal cord was tightly adhesive around the dural defect. We released the adhesion of the spinal cord and the dural defect under the spinal cord, and the dural defect was repaired using an artificial dura mater. CONCLUSIONS: The release of adhesion around dural defect and repair of dural defect under spinal cord monitoring resulted in a satisfactory neurologic recovery. Surgical repair of the dural defect with a dural substitute was necessary.

Comparison of clinical features and outcomes of staphylococcus aureus vertebral osteomyelitis caused by methicillin-resistant and methicillin-sensitive strains.

The causative organism of vertebral osteomyelitis (VO) was almost exclusively Staphylococcus aureus. The purpose of this study was to delineate the differences in clinical features and outcomes between patients with methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) VO. This study retrospectively reviewed 85 consecutive patients with VO treated between 2005 and 2011. Surgical site infections were excluded. Diagnosis was made by cultures of either blood or biopsied samples. We identified 16 cases of MRSA VO and 14 cases of MSSA VO. The average follow-up period was 18.5 months. Clinical features and outcomes were analyzed. Males were more likely to have MRSA VO than MSSA VO (87.5% vs. 35.7%). In regards to the number of co-morbidities, patients with MRSA VO had significantly more co-mobidities than patients with MSSA VO. Additionally, the rate of patients who underwent surgical procedure (excluding spinal surgeries in the affected region) within 3 months were significantly higher in the MRSA VO group than the MSSA VO group (56.3% vs. 14.3%). White blood cell counts and C-reactive protein levels in patients with both strains significantly improved 4 weeks after the initial treatment compared with the pretreatment values. The recurrence rate within 6 months tended to be higher for MRSA VO (37.5% vs. 7.1%), but no significant difference in mortality was observed between the two VO types. In conclusion, male sex, multiple co-morbidities and previous non-spine surgery were significant risk factors for VO due to MRSA as compared to MSSA. The recurrence rate within 6 months tended to be higher for MRSA VO. Patients with MRSA VO should be monitored carefully for recurrence by sequential clinical, radiographic, and laboratory examinations during the treatment course.

Cervical lateral mass screw fixation without fluoroscopic control: analysis of risk factors for complications associated with screw insertion.

OBJECTIVE: To examine the outcome of cervical lateral mass screw fixation focusing on analysis of the risk factors for screw-related complications. METHODS: Ninety-four patients who underwent posterior cervical fixation with a total of 457 lateral mass screws were included in the study. The lateral mass screws were placed using a modified Magerl method. Computed tomographic (CT) images were taken in the early postoperative period in all patients, and the screw trajectory angle was measured on both axial and sagittal plane images. RESULTS: In the postoperative CT analysis for the screw trajectory, 56.5 % of the screws were directed within the acceptable range (within 21-40° on both axial and sagittal planes). As intraoperative screw-associated complications, 9.6 % of the screws were found to contact with or breach the vertebral artery foramen. In this group, the screw trajectory angle on axial plane was significantly lower than in the group without contact. Facet violation was observed in 13 screws (2.8 %). This complication was associated with a significantly lower trajectory angles in the sagittal plane, predominantly at C6 level (69.2 %). In the patient chart review, no serious neurovascular injuries were documented. CONCLUSIONS: In the analysis of potential risk factors for violation of the VA foramen as well as FV during screw insertion, the former incidence was significantly related to the screw trajectory angle (lack of lateral angulation) in the axial plane, while the latter incidence was related to a poor screw trajectory angle in the sagittal plane.