Navigation for Tubular Decompression of the L5 Nerve Root Ganglion after Cement Leakage via a Wiltse Approach.

Osteoporotic vertebral fractures are a widespread problem in the elderly population. In experienced hands, treatment procedures are safe and can be done in a minimally invasive fashion. Nevertheless, in rare cases, severe complications may occur. We present a case report of cement leakage after vertebroplasty of L5 compressing the nerve root with neurological signs and radiculopathy. An 86-year-old female patient was introduced to our department with severe L5 nerve root radiculopathy and a foot flexion paresis after vertebroplasty of L5. Computed tomography (CT) of the lumbar spine revealed extraforaminal extravasation of cement around the nerve root causing significant compression. The patient underwent surgical revision using spinal navigation for skin incision, retractor placing, and verification of the cement extravasation. The cement plombage was removed, and the patient improved immediately. Sufficient decompression of the nerve root after cement leakage can be achieved using a spinal navigation setup in combination with intraoperative CT.

Clinical and radiological effect of medialized cortical bone trajectory for lumbar pedicle screw fixation in patients with degenerative lumbar spondylolisthesis: study protocol for a randomized controlled trial (mPACT).

BACKGROUND: Spinal fusion with pedicle screw fixation represents the gold standard for lumbar degenerative disc disease with instability. Although it is an established technique, it is nevertheless an invasive intervention with high complication rates. Therefore, minimally invasive approaches have been developed, the medialized bilateral screw pedicel fixation (mPACT) being one of them. The study objective is to evaluate prospectively the efficacy and safety of the mPACT technique compared with the traditional trajectory for degenerative lumbar spondylolisthesis. METHODS/DESIGN: This is a single-center, randomized, controlled, parallel group, superiority trial. A total of 154 adult patients are allocated in a ratio of 1:1. Sample size and power calculation were performed to detect the minimal clinically important difference of 10%, with an expected standard deviation of 20% in the primary outcome parameter, the Oswestry Disability Index, with power of 80%, based on an assumed maximal dropout rate of 20%. Secondary outcome parameters include the EuroQoL 5-Dimension questionnaire, the Beck Depression Inventory, the painDETECT questionnaire and the "timed up and go" test. Furthermore, radiological and health economic outcomes will be evaluated. Follow up is performed until 5 years after surgery. Major inclusion criteria are lumbar degenerative spondylolisthesis with Meyerding grade I or II, which qualifies for decompression and fusion by medialised posterior screw placement with cortical trajectory (mPACT) or by a traditional trajectory for lumbar pedicle screw placement. DISCUSSION: This trial will contribute to the understanding of the short-term and long-term clinical and radiological postoperative course in patients with lumbar degenerative disc disease, in which the mPACT technique is used. TRIAL REGISTRATION: ISRCTN registry, ISRCTN99263604 . Registered on 3 November 2016.

Thoracic corpectomy for neoplastic vertebral bodies using a navigated lateral extracavitary approach-a single-center consecutive case series: technique and analysis.

Thoracic myelopathy is often caused by vertebral body fractures resulting from neoplastic conditions, traumatic events, or infectious diseases. One of the preferred procedures for treating it is the lateral extracavitary approach (LECA) with single-level or multilevel decompressive corpectomy and reconstruction. The aim of this retrospective study was to analyze the thoracic lateral extracavitary approach with corpectomy using vertebral body replacement systems (VBR-S) and dorsal reconstruction. Twenty-four patients with metastatic or primary lesions of thoracic vertebrae T2-T12 underwent spinal decompression and ventral column reconstruction with correction of spinal deformity via a LECA. One-level to four-level corpectomies were performed with additional navigated dorsal pedicle screw fixation at an average of two levels above and below the corpectomy lesion. None of the patients received preoperative spinal embolization, and the majority of the patients were admitted to radiotherapy postoperatively. Their mean age was 56 years (± 15), with a female-to-male sex ratio of 8 to 16. Patients with a minimum follow-up period of 16 months were included. The Karnofsky index, preoperative and postoperative numeric rating scale (NRS), and Frankel scale were measured. In addition, intraoperative loss of blood (LOB), units of packed red blood cell (PRBC) transfusions, the duration of the operation, and the hospitalization period were evaluated and correlated with preoperative and postoperative values. The majority of the patients were suffering from metastatic lesions and were treated with a 1 level corpectomy (median 1 level, range 1 to 4). The mean duration of surgery was 288 min (± 121) and the mean LOB was 1626 mL (± 1486 mL), with approximately two PRBC units per patient used. All patients were transferred to the intensive care unit (ICU) postoperatively, with a mean ICU stay of 2.0 days (± 1 day). The mean hospitalization period was 13 days (± 7 days). No implant-related failures or procedure-related deaths were observed. Significant differences were noted between the preoperative and postoperative Karnofsky index (74 vs. 84%) and NRS (4 vs. 2). One patient required revision surgery due to a superficial wound infection, and another needed revision surgery due to a dural tear. In another patient, an iatrogenic dural tear was repaired during the same surgical procedure and did not lead to postoperative complications. Four pleural effusions and one pneumothorax were observed, so that the overall complication rate was approximately 33%. Four of the patients died within 2 years of the operation due to progression of the primary disease. Lateral corpectomy and sagittal reconstruction of the thoracic spine using VBR-S conducted via a navigated LECA approach yields favorable results, despite the burden of neoplastic disease. These challenging procedures are accompanied by increased LOB and hospitalization periods, with moderate transfusion requirements. Surgery-related complications are low and local tumor control is satisfactory, despite the progression of the underlying neoplastic disease. However, optimal surgical therapy does not ensure long-term survival.Study design Retrospective analysis of thoracic corpectomiesLevel of evidence 4.

How I do it-optimizing radiofrequency ablation in spinal metastases using iCT and navigation.

BACKGROUND: Exact positioning of the radiofrequency ablation (RFA) probe for tumor treatment under fluoroscopic guidance can be difficult because of potentially small inaccessible lesions and the radiation dose to the medical staff in RFA. In addition, vertebroplasty (VP) can be significantly high. METHOD: Description and workflow of RFA in spinal metastasis using iCT (intraoperative computed tomography) and 3D-navigation-based probe placement followed by VP. CONCLUSION: RFA and VP can be successfully combined with iCT-based navigation, which leads to a reduction of radiation to the staff and optimal probe positioning due to 3D navigation.

Transoral vertebroplasty of the lateral mass of C1 using image guidance.

BACKGROUND: Osteolytic lesions of the anterior aspects of C1 (lateral mass) are difficult to address in a minimally invasive fashion and are often treated by craniocervical instrumentation. METHODS: We report the feasibility and technical method of transoral vertebroplasty of the lateral mass of the atlas using image guidance and describe the workflow of the procedure. To our knowledge, there has not yet been a technical description of a transoral vertebroplasty using image guidance. RESULTS: Adequate positioning of the pedicle access needle using image guidance for addressing the lateral mass of C1 through a transoral, permuceous access can be achieved. CONCLUSIONS: With the assistance of image guidance, it is safe and feasible to access the lateral mass of the atlas. This constitutes a minimally invasive and fast alternative for introducing the bone needle to C1 rather than using a fluoroscopic device alone.

Cement-augmented screws in a cervical two-level corpectomy with anterior titanium mesh cage reconstruction: a biomechanical study.

STUDY DESIGN: Biomechanical investigation. PURPOSE: Cervical two-level corpectomies with anterior-only instrumentation are associated with a high rate of implant-related complications. These procedures, therefore, often require an additional dorsal instrumentation to prevent screw loosening. Cement augmentation of the anterior screws in two-level corpectomies might stabilize the construct, so that a second dorsal procedure could be avoided. To evaluate the screw anchorage in cervical anterior-only procedures, an ex vivo evaluation of the range of motion (ROM) in two-level corpectomies (C4 and C5), with and without cement augmentation of the anterior screws, was carried out in this study. METHODS: Twelve human cervical cadaveric spines (C2-T1) were divided into two groups of six specimens each. Corpectomies were performed in C4 and C5, with grafting and anterior instrumentation with and without cement augmentation of the anterior screw-and-plate system (0.3-0.5 mL cement/screw). Flexibility tests with pure moments (1.5 Nm) were carried out before and after three cyclic loading periods of 5000 cycles with increasing eccentric forces (100, 200, and 300 N). RESULTS: After corpectomy and instrumentation, the control group and the augmented group showed a significant reduction in ROM in comparison with the native states with average ROMs of 49% (±17%) and 24% (±10%), respectively (P = 0.006). The ROM in the control group increased significantly in all motion directions in the course of cyclic loading and approached native values after the third cyclic loading period, with an overall ROM of 78% (±22%). In contrast, the augmented group maintained a significantly decreased ROM in all motion directions during cyclic loading, with a final ROM of 32% (±14%) after the third period of cyclic testing. Inter-group comparison demonstrated a significant difference between the two groups in the course of cyclic loading. The cement-augmented group outperformed the control group in all motion directions, with a significantly lower ROM after all three cyclic loading periods. CONCLUSIONS: A two-level corpectomy with cement-augmentation results in a significantly reduced ROM. In comparison with the conventional anterior screw-and-plate fixation, it represents a significantly stabilized two-level anterior construct. This might be a treatment option for patients with a two-level corpectomy associated with reduced bone mineral density, to avoid an additional dorsal instrumentation.

Intradural synovial cyst of the atlantoaxial joint: a case report.

BACKGROUND: Intradural synovial cysts of the cervical spine represent a rare disease entity, causing stenosis of the spinal canal and thereby leading to progressive myelopathy. In particular, at the cranio-cervical junction early intervention is necessary to prevent permanent neurological dysfunction. We present the case of a 74-year-old man who presented with moderate cervicogenic headache, gait disturbance and progressive left-sided weakness. Magnetic resonance imaging (MRI) of the cervical spine confirmed a left-sided cystic mass located anteriorly at the craniovertebral junction compressing the surrounding structures. METHOD: Surgical decompression was performed by means of a minimal left-sided laminectomy of C1. Postoperatively, the patients symptoms slowly improved, albeit a persistent ataxic gait. RESULTS: Intraoperatively, a large intradural cyst was removed via a minimal suboccipital craniectomy combined with laminectomy of C1. Histopathological evaluation revealed a synovial cyst without any features of neoplasia. Despite not using craniocervical instrumentation, no clinical or radiological signs of atlantoaxial instability were observed up to 2 years after surgery. CONCLUSIONS: Cystic lesions located at the atlanto-axial joint are a rare cause of cervical myelopathy. Preoperative imaging of the cervical spine should include not only MRI and computerised tomography (CT) but also dynamic imaging. Dorsal decompression without instrumentation prevents progressive neurological decline and may allow cord function to recover. If there is additional preoperative instability, instrumentation and fusion may be necessary.

Driving reaction time before and after surgery for disc herniation in patients with preoperative paresis.

BACKGROUND CONTEXT: The effect of many types of surgeries on driving reaction time (DRT) has been reported. Although lumbar disc herniation is one of the most common spinal diseases, the effect on DRT has not been investigated. PURPOSE: To assess the effect of left- and right-sided pareses caused by lumbar disc herniation on DRT before and after surgery. STUDY DESIGN: Controlled prospective clinical trial. PATIENT SAMPLE: Patients undergoing disc surgery. OUTCOME MEASURES: Impact of paresis caused by lumbar disc herniation and disc surgery on DRT. METHODS: Forty-two consecutive patients (mean age, 50.3 years) were tested for DRT 1 day before surgery, postoperatively before hospital discharge, and 5 weeks after surgery. Visual analogue scale (VAS) for back and leg pain as well as pain medication and patients' driving frequency were recorded. RESULTS: Significant improvement of DRT after surgery was seen in patients with left- and right-sided pareses (p<.005). For the right-sided paresis group, the preoperative DRT was 761 ms (median, interquartile range [IQR]: 490), 711 ms (median, IQR: 210) immediately postoperatively, and 645 ms (median, IQR: 150) at follow-up (FU). For the left-sided paresis group, DRT was 651 ms (median, IQR: 270) preoperatively, 592 ms (median, IQR: 260) postoperatively, and 569 ms (median, IQR: 140) at FU. Significant differences between right- and left-sided pareses were identified preoperatively and at FU testing (p<.005). No correlation was found between VAS for leg or back pain and DRT. Historical control subjects had a DRT of 487 (median, IQR: 116), which differed significantly at all three test times (p<.001). CONCLUSIONS: A significant reduction in DRT in patients with right- and left-sided pareses was found after surgery, indicating a positive effect of surgery. The improvement in DRT seen immediately postoperatively and the lack of a generally accepted threshold for DRT would suggest that for both patient samples, it is safe to continue driving after hospital discharge. However, patients should be informed accordingly.

Pedicle-Based Non-fusion Stabilization Devices: A Critical Review and Appraisal of Current Evidence.

Over the last decades, spinal fusion has become one of the most important principles in surgical treatment of spinal pathologies. Despite the undoubted benefits of fusion surgery, there are several drawbacks associated with this technique, including adjacent segment degeneration and pseudoarthrosis. Based on biomechanical data, dynamic stabilization of the spine is intended to ameliorate adjacent level degeneration by stabilizing vertebral motion in defined planes and mimicking natural spine movements.In this paper, we review the literature and discuss past and present pedicle-based non-fusion dynamic stabilization devices. Although there is a paucity of high-quality prospective trials, studies have indicated both promising and disappointing results. In comparison to 360° fusion surgery, the perioperative risk seems to be lower. Other complications like screw loosening, however, have been reported with various systems, while a reduction of adjacent segment disease has not yet been demonstrated. The necessary degree of restabilization to achieve pain-free motion seems to vary greatly between patients and current systems are far from perfection. If these problems can be solved, dynamic stabilization may nevertheless be an important option of spinal surgery in the future.

Driving reaction time before and after surgery for lumbar disc herniation in patients with radiculopathy.

PURPOSE: Although patients scheduled to undergo lumbar disc surgery often ask when they are allowed to drive a motor vehicle again, there are no published recommendations on this subject. METHODS: We conducted a prospective study in 46 consecutive patients (mean age 48.9 years) to determine driving reaction time (DRT) before and after surgery in patients with lumbar disc herniation. Of the patients 23 had left-side radiculopathy and 23 right-side radiculopathy. Driving reaction time as well as back and leg pain were evaluated preoperatively, on the day of discharge from hospital and at the 5-week follow-up examination (FU). 31 healthy subjects were tested as controls. RESULTS: Significant improvement in DRT was seen for both patient samples (p < 0.05). For patients with a right-side radiculopathy preoperative DRT was 664 ms (median, IQR: 241), which was reduced to 605 ms (median, IQR: 189) immediately postoperatively and to 593 ms (median, IQR: 115) at FU. For patients with a left-side radiculopathy DRT was 675 ms (median, IQR: 247) preoperatively, 638 ms (median, IQR: 242) postoperatively and 619 ms (median, IQR: 162) at FU. Pain was moderately correlated to DRT. Control subjects had a driving reaction time of 487 (median, IQR: 116), which differed significantly from patients at all three testing times (p < 0.001). CONCLUSION: Our data indicate a positive effect of the surgery on driving ability. Therefore, we would suggest that for both patient samples it is safe to continue driving after hospital discharge. However, patients have to be informed about increased DRT caused by radiculopathy already before surgery.

The N-end rule ubiquitin-conjugating enzyme, HR6B, is up-regulated by nerve growth factor and required for neurite outgrowth.

Neurite outgrowth is accompanied by increased levels of high molecular weight ubiquitin conjugates and decreased levels of free ubiquitin. The search for enzymes responsible for increased utilization of ubiquitin revealed the ubiquitin-conjugating enzyme, HR6B (yeast UBC2/RAD6), increased on mRNA and protein level in rat pheochromocytoma (PC12) cells after treatment with nerve growth factor (NGF). HR6B participates in 'N-end rule degradation' that is implicated in the cleavage of proteins with destabilizing N-terminal residues (bulky hydrophobic or basic amino acids) and requires UBR1, the ubiquitin ligase binding N-end rule target proteins. Down-regulation of HR6B or UBR1 mRNA by small interfering RNA and treatment with Leu--Ala, a dipeptide-inhibitor of UBR1, inhibit neurite outgrowth of PC12 cells. Furthermore, axonal regeneration of adult sensory neurons, which express prominent nuclear and membrane-associated HR6 immunoreactivity, is reduced by Leu--Ala in vitro. Therefore, N-end rule ubiquitination is required for neuronal differentiation of PC12 cells and may be involved in axonal regeneration of peripheral neurons.