Surgical treatment of four segment lumbar spondylolysis: A case report

BACKGROUNDFour-level lumbar spondylolysis is extremely rare. So far, only 1 case has been reported in the literature. CASE SUMMARYA 19-year-old man presented with severe back pain irresponsive to conservative therapies for 2 years. Lumbar radiographs and two-dimensional computed tomography scan showed four segment lumbar spondylolysis on both sides of L2-L5. Lumbar magnetic resonance imaging showed normal signal in all lumbar discs. Because daily activities were severely limited, surgery was recommended for the case. The patient underwent four-level bilateral isthmic repair at L2-L5. During surgery, L2-L5 isthmi were curetted bilaterally, freshened, and then grafted with autologous iliac bone that was bridged and compressed with a pedicular screw connected to a sub-laminar hook by a short rod. The symptoms of back pain almost disappeared. He has been followed-up for 96 mo, and his symptoms have never recurred. Fusion was found in all repaired isthmi 14 mo after surgery according to evaluation of lumbar radiography and computed tomography scan.CONCLUSIONWe report here 1 case of four-level lumbar spondylolysis that was treated successfully with direct isthmic repair.     

Comparison of three different types of splints and templates for maxilla repositioning in bimaxillary orthognathic surgery: a randomized controlled trial

The selection and implementation of a plan for maxillary surgery is of the utmost importance in achieving the desired outcome for the patient undergoing two-jaw orthognathic surgery. Some splint-based and splintless methods, accompanied by computer-assisted techniques, are helpful in improving surgical plan implementation. However, randomized controlled trials focused on this procedure are lacking. This study included 61 patients who underwent bimaxillary surgeries. The patients were randomly assigned to a conventional resin occlusal splint (CROS) group, a digital occlusal splint (DOS) group, or a digital templates (DT) group, in a 1:1:1 ratio. The mean linear distance between the planned and actual postoperative positions of eight selected points on the surfaces of the maxillary teeth was selected as the outcome measure. The distance was significantly smaller in the DT group (1.17 ± 0.66 mm) when compared to both the CROS group (2.55 ± 0.95 mm, P < 0.05) and DOS group (2.15 ± 1.12 mm, P < 0.05). However, the difference between the CROS group and DOS group was not statistically significant. These findings indicate that using digital templates results in the best performance in transferring the surgical plan to the operation environment as compared to the other two types of splints. This suggests that the application of digital templates could provide a reliable treatment option.     

神经外科手术机器人置入椎弓根螺钉的精准性

目的 探讨神经外科手术机器人在人体腰椎模型进行椎弓根螺钉置入的精准性。方法 利用O型臂影像系统对模型进行正侧位扫描，并三维重建，获取3D-CT数据，传入手术机器人系统，规划椎弓根螺钉的最佳进钉点和进钉方向。手术机器人系统利用3D-CT数据自动注册后，置入椎弓根螺钉。应用置钉前后的3D融合图像，按照Gertzbein-Robbins分级评估置钉的准确性。结果 共置入39枚椎弓根螺钉，其中37枚螺钉完全位于椎弓根内，2枚螺钉突破椎弓根的内壁2 mm以内。螺钉与原规划钉道的平均偏移距离为（1.45±0.67）mm。螺钉在进钉点的滑移方向:内下方16枚（41.03%），外上方6枚（15.38%），下方6枚（15.38%），外下方5枚（12.82%），内上方4枚（10.26%），内方1枚（2.56%），上方1枚（2.56%）。结论 神经外科手术机器人置入椎弓根螺钉具有较高的精准性。     

Analysis of an in-house technique for temporary mandibulotomy and its impact on postoperative radiotherapy

The purpose of this study was to describe a newly developed procedure for temporary mandibulotomy and subsequent osteosynthesis. Clinical outcomes were evaluated, including complications and the impact on postoperative treatment, particularly postoperative radiotherapy. Twenty-four patients underwent temporary mandibulotomies for the surgical resection of malignancies located in the posterior oral or oropharyngeal region. All were treated with postoperative radiotherapy. An angulated median mandibulotomy was followed by osteosynthesis with three anchor screws directed towards the inferior aspect of the mandible. Anchor screws are modified conventional lag screws that include an additional biconcave washer. This modification prevents the screw heads from cracking into the cancellous bone during tightening, improving their biomechanical qualities considerably. Insertion of screws at any angle to the bony surface therefore becomes possible, which is a precondition for this technique. Minor complications occurred in two patients in the early postoperative period. However, complications causing bony non-union, leading to postponed postoperative radiotherapy were not noted in this cohort.     

Endovascular management of multiple intracranial dural arteriovenous fistulas

Background and purposeMultiply occurring intracranial dural arteriovenous fistulas (dAVFs) have been documented but rarely occur, and neither pathogenesis nor prognosis is clearly understood. This study was conducted to analyze angiographic characteristics of multiple dAVFs and to chronicle our treatment experience.MethodsBetween April, 2002 and January, 2018, data prospectively collected from 310 patients with intracranial dAVFs were systematically reviewed, assessing clinical and anatomic outcomes of endovascular treatment in 32 patients with multiple dAVFs (≥ 2 fistulas each). Lesions were categorized as multifocal or diffuse type, depending on presentation, and further characterized as progressive or non-progressive disease.ResultsOverall, 18 patients (56.3%) experienced aggressive presentations, including intracerebral hemorrhage or venous infarction. Cortical venous reflux (CVR) was observed in 26 patients (81.3%), and sinus thrombosis or occlusion was seen in 24 (75.0%). Clinical outcomes in patients with multifocal fistulas (n = 11) were excellent (100%), marked by a moderately high rate of complete occlusion (54.5%). Those with progressive disease (n = 10) regularly displayed certain angiographic findings, namely diffuse configuration (100%), sinus thrombosis (100%), and CVR (100%). Complete anatomic obliteration was achieved in 12 patients (37.5%), and in 26 patients (81.3%), clinical outcomes were favorable.ConclusionMultiple dAVFs are typically aggressive at presentation, given strong associations with CVR and sinus thrombosis. In diffuse-type fistulas, the potential to recur or progress is high. Although definitive treatment poses a challenge, outcomes of endovascular therapeutics may be still optimized in this setting through strategic procedural modifications and careful follow-up monitoring.     

Focal hole versus screw stimulation to prevent false negative results in detecting pedicle breaches during spinal instrumentation

ObjectiveWe describe a stimulus-evoked EMG approach to minimize false negative results in detecting pedicle breaches during lumbosacral spinal instrumentation.MethodsIn 36 patients receiving 176 lumbosacral pedicle screws, EMG threshold to nerve root activation was determined using a focal probe inserted into the pilot hole at a depth, customized to the individual patients, suitable to position the stimulating tip at the point closest to the tested nerve root. Threshold to screw stimulation was also determined.ResultsMean EMG thresholds in 161 correctly fashioned pedicle instrumentations were 7.5 mA ± 2.46 after focal hole stimulation and 21.8 mA ± 6.8 after screw stimulation. Direct comparison between both thresholds in individual pedicles showed that screw stimulation was always biased by an unpredictable leakage of the stimulating current ranging from 10 to 90%. False negative results were never observed with hole stimulation but this was not true with screw stimulation.ConclusionsFocal hole stimulation, unlike screw stimulation, approaches absolute EMG threshold as shown by the lower normal limit (2.6 mA; p < 0.05) that borders the upper limit of threshold to direct activation of the exposed root.SignificanceThe technique provides an early warning of a possible pedicle breakthrough before insertion of the more harmful, larger and threaded screw.     

Treatment of skeletal open bite using a navigation system: CAD/CAM osteotomy and drilling guides combined with pre-bent titanium plates

Severe skeletal open bite associated with posterior vertical maxillary excess and mandibular deformity is considered a difficult problem in orthodontic and surgical treatment. This study used a navigation system for the correction of severe skeletal open bite in order to accurately transfer the virtual plan to the actual operation and achieve precise rigid internal fixation in bimaxillary osteotomies of the jaws. Twelve patients with a severe skeletal open bite associated with vertical maxillary excess and mandibular deformity were recruited. All patients underwent Le Fort I osteotomy and bilateral sagittal split ramus osteotomy with the guidance of this navigation system. Computed tomography and cephalometric examinations were performed to evaluate the correction of the deformity. Deviations between the simulated plan and actual postoperative outcome were measured to determine the precision of the surgery. Satisfactory and stable results were achieved in all patients postoperatively, without complications or relapse during follow-up. Photographs and cephalometric evaluations showed that the facial profile and occlusion were improved. Assessment of the deviations between the simulated plan and actual postoperative outcome showed that the navigation system can precisely transfer the virtual plan to the actual operation. The results suggest that the navigation system can accurately transfer the virtual plan to the actual operation during bimaxillary jaw osteotomies, without relapse, in patients with a severe skeletal open bite.