Background:The long-term outcome of surgery for adolescent idiopathic scoliosis (AIS) using segmental pedicle screw constructs is sparsely described in the scientific literature. Methods:Retrospective case series of 120 consecutive patients operated for AIS using segmental pedicle screw constructs. Age between 11 and 21 years of age at the time of surgery (25 males) and followed median 9 years after surgery. Outcome measures consisted of radiological variables, the SRS-22 and the EQ-5D-5L questionnaires, questions concerning work status and the most advanced educational level at last follow-up. An electronic questionnaire was answered in 120 of 148 cases (81%) and 112 (76%) showed up for the long-term radiology control. Preoperative PROMS were available from the national research register for spine surgery. Attributable to the incompleteness of the register only a third of the PROM data were paired. Results:The frequency of complications was 12.5%. Mean curve correction was 78% immediately preoperative with a 4° increase at last follow-up. SRS-22 total/self-image and the EQ-5D utility scores were significantly improved at last follow-up. At last follow-up 84% were satisfied or very satisfied with the results of the surgical intervention. Socioeconomic factors, Lenke type 2, number of levels instrumented and curve correction were important predictors for satisfaction in a logistic regression model (AUC 85%). Conclusions:Only 16% were not satisfied with the results of AIS surgery after 5 to 15 years. Total PROM scores and self-image scores were significantly improved at last follow-up. Socioeconomic factors are important when analyzing the results of AIS surgery.

Introduction: Previously, only 40 cases with extradural hemangioblastoma at the spinal nerve (none at the T1 nerve root) have been described in the medical literature. In toto, resection of this hypervascular tumor is essential to avoid bleeding complications. Surgery for hemangioblastoma at the cervicothoracic junction is complex and nerve resection of the T1 results in specific neurodeficits of the hand muscles which are not well known. Case Report: A 34-year-old woman was diagnosed with a slowly growing tumor located at the left foramen T1/T2. Pressure from the tumor resulted in Horner’s syndrome and pain and paresthesia in the upper extremity. The tumor was resected in toto through a posterior midline approach and rib resection and transection of the left T1 and T2 spinal nerves. T2 hemicorporectomy and spinal stabilization were performed to gain access to and mobilize the tumor ventrally. Ptosis decreased after surgery and no neurodeficit was observed except the expected deficit (no deficit was present preoperatively) caused by the T1 resection specifically a small decrease in strength of the abductor and flexor pollicis brevis and opponens pollicis and the lateral two lumbricals. Histological examination of the tumor demonstrated a hemangioblastoma. von Hippel-Lindau disease was ruled out by genetic testing of the patient’s blood. Eight-month postoperatively, all pre-operative symptoms had decreased considerably and the radiographic examination shoved unchanged pedicle screw/rod stabilization of the cervicothoracic junction. Conclusion: Hemangioblastoma is a rare hypervascular tumor very rarely located at the spinal nerve. The tumor should be resected in toto to avoid recurrence and bleeding. In the current case, the location was at the T1 root necessitating complex surgery with laminectomies and hemicorporectomy of T2 and a posterior rib resection/thoracotomy. Spinal stabilization is mandatory. Preferably embolization should be performed preoperatively. T1 transection results in a specific neurodeficit which should be explained to the patient preoperatively. The patients should undergo genetic testing for Hippel-Lindau disease. Keywords: Hemangioblastoma, von Hippel-Lindau disease, in toto resection, hemicorporectomy, spinal nerve root T1 nerve lesion.

Anterior lumbar interbody fusion (ALIF) is a wellestablished treatment. Using poly-ether-ether-ketone (PEEK) cages for ALIF procedure take advantage of the relative radiolucency of PEEK cages .The goal of this study was to determine the radiological outcomes and complications after ALIF surgery.

Abstract Background:Anterior lumbar interbody fusion (ALIF) is a well-established treatment with various advantages and disadvantages. One specific advantage of ALIF combined with posterolateral fusion is the high union rate. Using poly-ether-ether-ketone (PEEK) cages for ALIF procedure takes advantage of the relative radiolucency of PEEK cages .The goal of this study was to determine the radiological outcomes and complications after ALIF surgery. Methods: Retrospective review of patients with ALIF (PEEK cage) surgery. Complications were noted. Bone union determined with Bridwell classification. Pre and post-operative X-rays, X-rays at the last follow-up reviewed. Anterior-posterior disc space height, segmental lordosis at the ALIF levels, lordosis of global lumbar columna measured. Results: 56 patients (M:25, F:31) and 80 ALIF cages were reviewed. The respective median age of surgery and follow-up duration(months) for these subgroups were; 47(37-54) / 14(12-24), 45(40-52) / 22(14-27), 57(51-62) / 17(16-25). The number of complications associated with the anterior approach were 9/56 or 16,0%. Bridwell fusion status were; 1 in 72 cages, 2 in 6 cages and 4 in 2 cages. The anterior disc space height and posterior disc space height L3/L4, L4/L5, L5/S1 significantly increased from preoperatively to immediately postoperatively and compared to the distance at last follow up. The anterior disc space height and posterior disc space height L4/L5, L5/S1 decreased significantly from immediately postoperatively to last follow-up. In L4/L5, the decrease in posterior disc space height from immediately postoperatively to last follow up was insignificant. Only for the L5/S1 level did the segmental lordosis increase significantly from preoperatively to immediately postoperatively and compared to the angle at last follow-up. No significant changes were noted in the lordosis of global lumbar columna measurements.Conclusions: The use of ALIF (PEEK cage) with posterior fixation resulted in very low non-union rate (2,5%). The approach related complications are comparable to the literature.

During surgery for spinal deformities, accurate placement of pedicle screws may be guided by intraoperative cone-beam flat-detector CT.

Paraspinal muscle damage is inevitable during conventional posterior lumbar fusion surgery. Minimal invasive surgery is postulated to result in less muscle damage and better outcome. The aim of this study was to monitor metabolic changes of the paraspinal muscle and to evaluate paraspinal muscle damage during surgery using microdialysis (MD). The basic interstitial metabolisms of the paraspinal muscle and the deltoid muscle were monitored using the MD technique in eight patients, who underwent posterior lumbar fusion surgery (six male and two female, median age 57.7 years, range 37-74) and eight healthy individuals for different positions (five male and three female, age 24.1 +/- 0.8 years). Concentrations of glucose, glycerol, and lactate pyruvate ratio (L/P) in both tissues were compared. In the healthy group, the glucose and glycerol concentrations and L/P were unchanged in the paraspinal muscle when the body position changed from prone to supine. The glucose concentration and L/P were stable in the paraspinal muscle during the surgery. Glycerol concentrations increased significantly to 243.0 +/- 144.1 microM in the paraspinal muscle and 118.9 +/- 79.8 microM in the deltoid muscle in the surgery group. Mean glycerol concentration difference (GCD) between the paraspinal muscle and the deltoid tissue was 124.1 microM (P = 0.003, with 95% confidence interval 83.4-164.9 microM). The key metabolism of paraspinal muscle can be monitored by MD during the conventional posterior lumbar fusion surgery. The glycerol concentration in the paraspinal muscle is markedly increased compared with the deltoid muscle during the surgery. It is proposed that GCD can be used to evaluate surgery related paraspinal muscle damage. Changing body position did not affect the paraspinal muscle metabolism in the healthy subjects.

Background and Purpose— Cerebral artery aneurysms rupture when wall tension exceeds the strength of the wall tissue. At present, risk-assessment of unruptured aneurysms does not include evaluation of the lesions shape, yet clinical experience suggests that this is of importance. We aimed to develop a computational model for simulation of fluid-structure interaction in cerebral aneurysms based on patient specific lesion geometry, with special emphasis on wall tension. Methods— An advanced isogeometric fluid-structure analysis model incorporating flexible aneurysm wall based on patient specific computed tomography angiogram images was developed. Variables used in the simulation model were retrieved from a literature review. Results— The simulation results exposed areas of high wall tension and wall displacement located where aneurysms usually rupture. Conclusion— We suggest that analyzing wall tension and wall displacement in cerebral aneurysms by numeric simulation could be developed into a novel method for individualized prediction of rupture risk.

The manipulation of the surgical field in laparoscopic surgery, through small incisions with rigid instruments, reduces free sight, dexterity, and tactile feedback. To help overcome some of these drawbacks, we present a prototype research and development platform, CustusX, for navigation in minimally invasive therapy. The system can also be used for planning and follow- up studies. With this platform we can import and display a range of medical images, also real-time data such as ultrasound and X-ray, during surgery. Tracked surgical tools, such as pointers, video laparoscopes, graspers, and various probes, allow surgeons to interactively control the display of medical images during the procedure. This paper introduces navigation technologies and methods for laparoscopic therapy, and presents our software and hardware research platform. Furthermore, we illustrate the use of the system with examples from two pilots performed during laparoscopic therapy. We also present new developments that are currently being integrated into the system for future use in the operating room. Our initial results from pilot studies using this technology with preoperative images and guidance in the retroperitoneum during laparoscopy are promising. Finally, we shortly describe an ongoing multicenter study using this surgical navigation system platform.