Search

Background: Atlantoaxial transarticular fixation, also called the Magerl technique, is said to be the most robust biomechanical method of fixation of the atlantoaxial vertebrae. However, the procedure carries a risk of spinal cord and vertebral artery injury during the insertion process, especially in patients with a high-riding vertebral artery. In this study, a computed tomography (CT)-based navigation system was used for preoperative planning and insertion. This investigation sought to determine the rate and direction of screw perforation as well as the incidence of screw loosening in computer-assisted atlantoaxial transarticular fixation. Methods: Sixty patients (31 men and 29 women; mean ± SD age: 65.3 ± 19.6 years) who received atlantoaxial transarticular screw insertion with preoperative CT navigation were analyzed. We investigated screw position and loosening by CT at the final follow-up. Results: Of the 108 screws inserted, the rate of Grade 2 or higher perforation was 4.6% (5/108). Nine of 81 (11.1%) screws inserted into the 44 patients who were followed for at least 6 months showed loosening. Logistic regression analysis revealed that unilateral insertion (odds ratio: 8.50, 95% confidence interval: 1.53-47.2, P = 0.014) was significantly associated with the incidence of screw loosening. Conclusions: The screw perforation rate of Grade 2 or higher in computer-assisted atlantoaxial transarticular screw fixation was 4.6%, with comparable frequencies of perforation direction. Unilateral insertion was a significant independent factor associated with screw loosening, which occurred in 11.1% of insertions. Clinical Relevance: Spine surgeons should follow up with patients with caution because screws with unilateral insertion are prone to loosening. Level of Evidence: 4. [ABSTRACT FROM AUTHOR]

Background: Venous thromboembolism (VTE) is a well-known complication after spine surgery. As many cases of cervical spine disease result in severe gait disturbance due to myelopathy, it may harbor a higher risk of VTE than other spinal disorders. However, few studies have focused primarily on cervical spine surgery to date. This investigation sought to determine the prevalence of VTE after cervical spine surgery and identify patient-based risk factors. Methods: The medical data of 341 consecutive patients (240 men and 101 women; mean age, 68.1 years) who underwent cervical spine surgery were retrospectively examined. Logistic regression models were employed to examine the prevalence, characteristics, and risk factors of postoperative VTE. Results: In this study, 2.6% of cervical spine surgery patients experienced postoperative VTE. In comparisons of VTE and non-VTE groups, significant differences were found for age (79.6 years vs 67.7 years, P < 0.01), 1-week postoperative Ddimer level (10.6 μg/mL vs 2.7 μg/mL, P < 0.01), and cardiovascular disease (44.4% vs 11.1%, P = 0.011). Multivariate analysis identified elevated postoperative D-dimer level and cardiovascular disease as significantly associated with postsurgical VTE with respective odds ratios of 1.54 and 9.52. Conclusion: Postoperative VTE in cervical spine surgery was seen in 2.6% of cases. Patients with elevated postoperative D-dimer level and cardiovascular disease may be at increased risk of VTE and may require additional observation. Clinical Relevance: Spine surgeons should take into account that patients with elevated postoperative D-dimer levels and cardiovascular disease may be at increased risk for VTE. Level of Evidence: 4. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective cohort study. Purpose: This study aimed to evaluate the relationship between C7 plumb line (C7PL) decompensation and the Scoliosis Research Society (SRS) 22-item patient questionnaire scores, including those related to self-image, preoperatively and 2 years after surgery. Overview of Literature: In the surgical treatment of adolescent idiopathic scoliosis (AIS), inferior trunk balance caused by C7PL decompensation can negatively affect patients' quality of life. However, there are few reports in the literature that describe or clarify how postoperative trunk imbalance affects each SRS-22 domain, including self-image domain scores. Methods: A total of 120 patients with AIS who underwent posterior spinal fusion from August 2006 to March 2017 at our facility and were followed up for 2 years or more were included. Radiological parameters were measured on whole-spine anteroposterior and lateral radiographs. Revised SRS-22 (SRS-22r) values were also recorded. Coronal trunk imbalance was defined as a deviation of =2.0 cm between the C7PL and the central sacral vertical line. Patients with and without coronal trunk imbalance at 2 years after surgery were defined as D (+) (decompensation type) and D (-), respectively. Mean SRS-22r values, including function, pain, self-image, mental health, and subtotal were compared between the D (+) and D (-) groups. Logistic regression analysis was performed to detect the preoperative factors related to D (+) using predictors, including curve type, maximum Cobb angle, and coronal trunk imbalance. Results: At 2 years after surgery, the D (+) group had a significantly lower self-image in the domain of SRS-22r scores compared with the D (-) group. Preoperative coronal trunk imbalance was significantly related to D (+) but not to significant changes in the postoperative SRS-22 score in any of the SRS-22 domains. Conclusions: Postoperative C7PL deviation lowers the self-image in patients with AIS. Patients with preoperative coronal trunk imbalance were significantly more likely to be D (+). [ABSTRACT FROM AUTHOR]

Study Design: Retrospective chart review. Purpose: This study evaluated long-term surgical outcomes of computer-assisted reconstruction using transarticular or cervical pedicle screws for cervical spine lesions caused by advanced rheumatoid arthritis (RA). Overview of Literature: We routinely employ C1-C2 transarticular and cervical pedicle screw instrumentation to reconstruct advanced and unstable RA cervical lesions. However, few reports are available on the long-term results of surgical reconstruction for rheumatoid cervical disorders, particularly regarding cervical pedicle screw fixation. Methods: Six subjects (all female) with RA cervical lesions who underwent atlantoaxial or occipitocervical fixation and were followed for at least 10 years were retrospectively studied. A frameless, stereotactic, optoelectronic, computed tomography-based image guidance system was used for correct screw placement. Variables including the Japanese Orthopaedic Association score, EuroQol, Ranawat value, and C2-C7 angle before and 2, 5, and 10 years after surgery were assessed along with the occurrence of subaxial subluxation (SAS). Results: Mean age at initial surgery was 58.2±7 years (range, 51-68 years), and mean follow-up period was 141±11 months (range, 122-153 months). Lesions included atlantoaxial subluxation (AAS, n=2) and AAS+vertical subluxation (n=4). Mean C2-C7 lordotic angle before and 2, 5, and 10 years after surgery was 20.1°±6.1°, 21.0°±4.0°, 18.8°±4.7°, and 17.8°±5.3°, respectively. SAS did not occur in cases maintaining the C2-C7 lordotic angle. In two cases where the C2-C7 lordotic angle declined from 5 years postoperatively, SAS occurred at the C2-C3 level in one and at the C4-C5 level in the other, both of which required reoperation. Conclusions: Patients with rheumatoid cervical lesions who undergo atlantoaxial or occipitocervical fixation using C1-C2 transarticular or pedicle screws carry a risk of SAS for up to 10 years postoperatively, which may require reoperation. [ABSTRACT FROM AUTHOR]

Myxopapillary ependymoma in childhood typically occurs in the central nervous system. There are few surgical cases of myxopapillary ependymoma of the cauda equina in children. We report a case of myxopapillary ependymoma of the cauda equina in a 5-yearold boy, who presented with leg pain and abnormal gait. Subtotal resection surgery was performed. Following the subtotal tumor resection, follow-up magnetic resonance imaging evaluation showed a recurrent tumor. As a result, we performed a second subtotal tumor resection and followed with postoperative radiation therapy. No further evidence of the disease has been noted elsewhere in the patient in over ten years of follow-up. Myxopapillary ependymoma of the cauda equina in a young boy was improved by subtotal tumor resection and postoperative radiation therapy. [ABSTRACT FROM AUTHOR]

Study Design: Seventy-five patients who had been treated for lumbar spinal stenosis (LSS) were reviewed retrospectively. Purpose: Invasion into the paravertebral muscle can cause major problems after laminectomy for LSS. To address these problems, we performed spinous process-splitting laminectomy. We present a comparative study of decompression of LSS using 2 approaches. Overview of Literature: There are no other study has investigated the lumbar spinal instability after spinous process-splitting laminectomy. Methods: This study included 75 patients who underwent laminectomy for the treatment of LSS and who were observed through follow-ups for more than 2 years. Fifty-five patients underwent spinous process-splitting laminectomy (splitting group) and 20 patients underwent conventional laminectomy (conventional group). We evaluated the clinical and radiographic results of each surgical procedure. Results: Japanese Orthopaedic Association score improved significantly in both groups two years postoperatively. The following values were all significantly lower, as shown with p -values, in the splitting group compared to the conventional group: average operating time (p =0.002), postoperative C-reactive protein level (p =0.006), the mean postoperative number of days until returning to normal body temperature (p =0.047), and the mean change in angulation 2 years postoperatively (p =0.007). The adjacent segment degeneration occurred in 6 patients (10.9%) in the splitting group and 11 patients (55.0%) in the conventional group. Conclusions: In this study, the spinous process-splitting laminectomy was shown to be less invasive and more stable for patients with LSS, compared to the conventional laminectomy. [ABSTRACT FROM AUTHOR]

Study Design: A retrospective study. Purpose: The present study aimed to evaluate mid-term results of cervical pedicle screw (CPS) fixation for cervical instability. Overview of Literature: CPS fixation has widely used in the treatment of cervical spinal instability from various causes; however, there are few reports on mid-term surgical results of CPS fixation. Methods: Record of 19 patients who underwent cervical and/or upper thoracic (C2-T1) pedicle screw fixation for cervical instability was reviewed. The mean observation period was 90.2 months. Evaluated items included Japanese Orthopaedic Association (JOA) score and C2-7 lordotic angle before surgery and at 5 years after surgery. Postoperative computerized tomography was used to determine the accuracy of screw placement. Visual analog scale (VAS) for neck pain and radiological evidence of adjacent segment degeneration (ASD) at the 5-year follow-up were also evaluated. Results: Mean JOA score was significantly improved from 9.0 points before surgery to 12.8 at 5 years after surgery (p =0.001). The C2-7 lordotic angle of the neutral position improved from 6.4° to 7.8° at 5 years after surgery, but this was not significant. The major perforation rate was 5.0%. There were no clinically significant complications such as vertebral artery injury, spinal cord injury, or nerve root injury caused by any screw perforation. Mean VAS for neck pain was 49.4 at 5 years after surgery. The rate of ASD was 21.1%. Conclusions: Our mid-term results showed that CPS fixation was useful for treating cervical instability. Severe complications were prevented with the assistance of a computed tomography-based navigation system. [ABSTRACT FROM AUTHOR]

Study Design: A retrospective study. Purpose: To evaluate the surgical results of cervical pedicle screw (CPS) fixation combined with laminoplasty for treating cervical spondylotic myelopathy (CSM) with instability. Overview of Literature: Cervical fixation and spinal cord decompression are required for CSM patients with instability. However, only a few studies have reported on CPS fixation combined with posterior decompression for unstable CSM patients. Methods: Thirteen patients that underwent CPS fixation combined with laminoplasty for CSM with instability were evaluated in this study. We assessed the clinical and radiological results of the surgical procedures. The Japanese Orthopedic Association (JOA) scoring system was used to evaluate the clinical results. The percentages of slip, difference in slip angle between maximum flexion and maximum extension of unstable intervertebrae, and perforation rate of CPS were evaluated. Results: The mean JOA scores before surgery, immediately after surgery, and at final follow-up were 9.1, 13.3, and 12.6, respectively. The mean percentages of slip before surgery, immediately after surgery, and at final follow-up were 9.1%, 3.2%, and 3.5%, respectively; there were significant improvements immediately after surgery and at final follow-up. The difference in slip angle between the maximum flexion and maximum extension of the unstable intervertebrae changed from 9.0° before surgery to 1.6° at the final follow-up. The perforation rate of CPS was 10.9%. Conclusions: The results suggest that CPS fixation combined with laminoplasty is an effective surgical procedure for treating CSM with instability. [ABSTRACT FROM AUTHOR]