Accuracy of pedicle screw placement using patient-specific template guide system.

BACKGROUND: Despite repeated efforts for accurate cervical pedicle screw insertion, malpositioning of the inserted screw is commonly noted. To avoid neurovascular complications during cervical pedicle screw insertion, we have developed a new patient-specific screw guide system. This study aimed to evaluate the accuracy of cervical PS placement using the new patient-specific screw guide system. METHODS: This study is a retrospective clinical evaluation of prospectively enrolled patients. Seventeen consecutively enrolled patients who underwent posterior cervical fusion using the guide system were included. Firstly, three-dimensional planning of pedicle screw placement was done using simulation software. A screw guide for each vertebra was constructed preoperatively. A total of 77 screws were inserted with the guides. Postoperative computed tomography was used to evaluate pedicle perforation, and screw deviations, between the planned and actual screw positions, were measured. RESULTS: A total of 76 screws (98.7%) were completely inside the pedicle (C3-7), without neurovascular injuries. The mean screw deviations from the planned trajectory at the narrowest point of the pedicle and at the entry point in the axial and sagittal planes were 0.56 ± 0.43 mm and 0.43 ± 0.35 mm and 0.43 ± 0.30 mm and 0.63 ± 0.50 mm, respectively. There were no significant differences in any parameter at different spinal levels. Angular deviations in the sagittal and axial planes were 2.94 ± 2.04° and 2.53 ± 1.85°, respectively. Sagittal angular deviations tended to increase in the cranial vertebra (C3 and C4) compared to the middle cervical spine. CONCLUSIONS: We demonstrated that our patient-specific screw guide is vital for guiding precise screw insertion in the cervical pedicle. This technique may be an effective solution for achieving precise screw insertion and reducing the incidence of complications.

Is the administration of vancomycin to operative field effective? Studying from operative wound drainage tube culture.

PURPOSE: To investigate the efficacy of application of VCM powder to surgical wounds. METHODS: A total of 314 patients who underwent posterior spinal instrumentation with local application of VCM (VCM group) were compared to 354 patients without VCM (control). The wound drainage tube was submitted for bacterial culture. The number of positive cultures, types of bacteria, and incidence of surgical site infections (SSI) were investigated. RESULTS: Drainage tube culture was positive in 1.6% (5/314 cases) and 7.3% (26/354 cases) of the VCM and control groups, respectively (P = 0.004). Among the five positive cases in the VCM group, one had an SSI, compared to three of 26 in the control group. Among the culture-negative cases, 0 and six, respectively, had an SSI. Finally, the incidence of SSI was 0.3% (1/314 cases) and 2.5% (9/354 cases), respectively. SSI occurred significantly less often in the VCM than in the control group (P = 0.01). The pathogenic bacterium was P. aeruginosa in the VCM group and MSSE, S. marcescens, methicillin-resistant S. aureus (MRSA), etc., in the control group. CONCLUSION: This study indicates that the amount of bacteria in the operative field was decreased by local application of VCM. However, the incidence of positive culture of VCM-resistant bacteria was not decreased by VCM. Importantly, pathogenic bacteria in the VCM group were only VCM-resistant, supporting the efficacy of VCM. In conclusion, local application of VCM decreases the amount of bacteria in the operative field and leads to fewer SSIs.

Myelopathy caused by chronic epidural hematoma associated with l1 osteoporotic vertebral collapse: a case report and review of the literature.

Epidural hematoma associated with osteoporotic vertebral collapse has not been reported yet in the literature. We report a case of myelopathy caused by chronic epidural hematoma associated with L1 osteoporotic vertebral collapse and review the relevant literature.

Local kyphosis reduces surgical outcomes of expansive open-door laminoplasty for cervical spondylotic myelopathy.

STUDY DESIGN: This retrospective study analyzed the effects of cervical alignment on surgical results of expansive laminoplasty (ELAP) for cervical spondylotic myelopathy (CSM). OBJECTIVE: To determine the limitation of posterior decompression by ELAP for CSM in the presence of local kyphosis. SUMMARY OF BACKGROUND DATA: Several studies have reported that cervical malalignment affected surgical outcomes of ELAP. However, there has been no report to demonstrate crucial determinants of surgical outcomes of ELAP for CSM in relation to cervical sagittal alignment. METHODS: The study group comprised 114 patients who underwent ELAP for CSM. All were followed up for more than 2 years. The Japanese Orthopedic Association (JOA) scoring system for cervical myelopathy (full score, 17 points) was used to evaluate surgical outcomes for each patient 2 years after surgery. Statistical analysis with multivariate logistic regression models was used to ascertain the risk factors affecting postoperative surgical outcomes. RESULTS: The average JOA scores were 9.9 points before surgery and 14 points 2 years after surgery. The recovery rate was 60.2%. Statistical analysis showed that signal intensity change on MRI and local kyphosis were the most crucial risk factors for poor surgical outcomes. Calculated with the logistic regression model, the highest risk of poor recovery was local kyphosis exceeding 13 degrees. CONCLUSIONS: The influence of cervical malalignment on neurologic recovery after ELAP for CSM was shown. When patients have local kyphosis exceeding 13 degrees, anterior decompression or posterior correction of kyphosis as well as ELAP should be considered. Expansive laminoplasty for CSM is best indicated for patients with local kyphosis less than 13 degrees.