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Davide Sparasci,1 Francesco Fanfulla,2 Raffaele Ferri,3 Debora Aricò,3 Daniela Distefano,4 Emanuele Pravatà ,4 Raphael Heinzer,5 José Haba-Rubio,5 Mathieu Berger,5 Gianna Carla Riccitelli,6– 8 Claudio Gobbi,6,8 Chiara Zecca,6,8,* Mauro Manconi1,8,* 1Sleep Medicine Unit, Neurocenter of Southern Switzerland, Lugano, Switzerland; 2Sleep Medicine Unit, Istituti Clinici Scientifici Maugeri, IRCCS, Scientific Institute of Pavia, Pavia, Italy; 3Sleep Research Centre; Department of Neurology I.C., Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Troina, Italy; 4Neuroradiology Clinic, Ospedale Regionale di Lugano, Neurocenter of Southern Switzerland, Lugano, Switzerland; 5Center for Investigation and Research in Sleep (CIRS), Lausanne University Hospital (CHUV) and University of Lausanne, Lausanne, Switzerland; 6Multiple Sclerosis Center, Neurocenter of Southern Switzerland, Lugano, Switzerland; 7Neuropsychology and Behavioural Neurology Research Unit, Neurocenter of Southern Switzerland, Lugano, Switzerland; 8Faculty of Biomedical Sciences, Università della Svizzera Italiana, Lugano, Switzerland*These authors contributed equally to this workCorrespondence: Raffaele Ferri, Sleep Research Centre; Department of Neurology I.C., Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Via Conte Ruggero 73, Troina, 94018, Italy, Email rferri@oasi.en.itBackground: Multiple sclerosis (MS) represents a risk factor for sleep disorders, but there are conflicting results about the prevalence and severity of sleep-related breathing disorders (SRBD) in MS. Most available data come from self-administered questionnaires.Objective: To conduct a polysomnographic study in MS focused on SRBD, compared to a group of healthy controls (HC), also considering the neuroimaging findings. To evaluate the impact of SRBD on vigilance, fatigue and depression in MS.Methods: In this cross-sectional, observational, instrumental study, 67 MS patients (men/women: 20/47; mean age: 50.6± 8.2 years) underwent PSG and maintenance of wakefulness test. Findings were compared to 67 age-, sex-, BMI-matched HC, by using parametric (Student’s t-test) and nonparametric statistics (chi-squared test). A subgroup analysis was then performed, evaluating the influence of brainstem (mesencephalic, pontine and medullary) lesions at neuroimaging on instrumental and clinical data: MS patients with at least one brainstem lesion vs MS patients without vs HC.Results: The frequency of SRBD was comparable in MS patients and HC. No MS patient had a central apnea index ≥ 2/h. The respiratory disturbance index (RDI) did not correlate to clinical parameters such as fatigue and depression. Patients with MS were drowsier than HC (47% vs 26%, p = 0.019) and showed a worse sleep pattern, in terms of duration, efficiency and architecture.Conclusion: Our study does not provide evidence of an association between MS-specific symptoms such as fatigue, sleepiness, depression and central or obstructive apneas, even in the presence of brainstem lesions.Keywords: sleep-related breathing disorders, multiple sclerosis, sleep quality, polysomnography

Study design Prospective multi-center study. Objective The study aimed to evaluate the accuracy of pedicle screw placement using a skin marker-based optical surgical navigation system for minimal invasive thoraco-lumbar-sacral pedicle screw placement. Methods The study was performed in a hybrid Operating Room with a video camera-based navigation system integrated in the imaging hardware. The patient was tracked with non-invasive skin markers while the instrument tracking was via an on-shaft optical marker pattern. The screw placement accuracy assessment was performed by three independent reviewers, using the Gertzbein grading. The screw placement time as well as the staff and patient radiation doses was also measured. Results In total, 211 screws in 39 patients were analyzed for screw placement accuracy. Of these 32.7% were in the thoracic region, 59.7% were in the lumbar region, and 7.6% were in the sacral region. An overall accuracy of 98.1% was achieved. No screws were deemed severely misplaced (Gertzbein grading 3). The average time for screw placement was 6 min and 25 secs (± 3 min 33 secs). The average operator radiation dose per subject was 40.3 µSv. The mean patient effective dose (ED) was 11.94 mSv. Conclusion Skin marker-based ON can be used to achieve very accurate thoracolumbarsacral pedicle screw placements.

To provide data about surgical workflow, accuracy, complications, radiation exposure, and learning curve effect in patients who underwent minimally invasive (MIS) transforaminal lumbar interbody fusion with navigation coupled with mobile intraoperative computed tomography.A retrospective analysis was performed of data from consecutive patients who underwent single- or double-level MIS transforaminal lumbar interbody fusion at a single institution; mobile intraoperative computed tomography combined with a navigation system was used as the sole intraoperative imaging method to place pedicular screws; decompression and interbody fusion were performed through a 22-mm tubular retractor. Clinical data, perioperative complications, accuracy of pedicular screw placement, and radiation exposure were analyzed. A learning curve effect on surgical time and accuracy was assessed.A total of 408 screws in 100 patients were analyzed. In all cases, spinal navigation allowed for identification of pedicular trajectories and greatly facilitated nerve root decompression through the MIS approach. Overall accuracy according to Heary classification was 95.3%. Nineteen screws (4.7%) presented a minor lateral breach (2 mm), not clinically significant. Surgical time, blood loss, and patient radiation exposure compared favorably with reported values from other series using three-dimensional navigation. A learning curve effect on surgical time, but not on screw accuracy, was identified.MIS transforaminal lumbar interbody fusion can now be performed without any radiation exposure to the surgeon and operating room staff, with almost absolute accuracy during screw positioning and tubular decompression. A learning curve effect on surgical time, but not on overall screw accuracy, may be expected.

BackgroundThe treatment of severe osteoporotic vertebral compression fractures (VCFs) with middle-column (MC) involvement, high fragmentation, large cleft and/or pedicular fracture is challenging. Minimally invasive 'stent-screw-assisted internal fixation' (SAIF) can reduce the fracture, reconstruct the vertebral body (VB) and fix it to the posterior elements.ObjectiveTo assess feasibility, safety, technical and clinical outcome of the SAIF technique in patients with severe osteoporotic VCFs.Methods80 treated vertebrae were analyzed retrospectively. Severe VCFs were characterized by advanced collapse (Genant grade 3), a high degree of osseous fragmentation (McCormack grade 2 and 3), burst morphology with MC injury, pediculo-somatic junction fracture, and/or large osteonecrotic cleft. VB reconstruction was evaluated on postprocedure radiographs and CT scans by two independent raters. Clinical and radiological follow-ups were performed at 1 and 6 months.ResultsSAIF was performed at 28 thoracic and 52 lumbar levels in 73 patients. One transient neurological complication occurred. VB reconstruction was satisfactory in 98.8% of levels (inter-rater reliability 96%, κ=1). Follow-up at 1 month was available for 78/80 levels and at 6 months or later (range 6–24, mean 7.9 months) for 73/80 levels. Significant improvement in the Visual Analog Scale score was noted at 1 and 6 months after treatment (pConclusionsSAIF is a minimally invasive, safe, and effective treatment for patients with severe osteoporotic VCFs with MC involvement.

ObjectivesTo describe a new technique to obtain minimally invasive but efficient vertebral body (VB) reconstruction, augmentation, and stabilization in severe osteoporotic and neoplastic fractures, combining two pre-existing procedures. The implant of vertebral body stents (VBS) is followed by insertion of percutaneous, fenestrated, cement-augmented pedicular screws that act as anchors to the posterior elements for the cement/stent complex. The screws reduce the risk of stent mobilization in a non-intact VB cortical shell and bridge middle column and pedicular fractures. This procedure results in a 360° non-fusion form of vertebral internal fixation that may empower vertebral augmentation and potentially avoid corpectomy in challenging fractures.Procedure detailsThis report provides step-by-step procedural details, rationale, and proposed indications for this procedure. The procedure is entirely percutaneous under fluoroscopic guidance. Through transpedicular trocars the VBS are inserted, balloon-expanded and implanted in the VB. Over k-wire exchange the transpedicular screws are inserted inside the lumen of the stents and cement is injected through the screws to augment the stents and fuse the screws to the stents.ApplicationsThis technique may find appropriate applications for the most severe osteoporotic fractures with large clefts, high-degree fragmentation and collapse, middle column and pedicular involvement, and in extensive neoplastic lytic lesions.ConclusionsStent-Screw-Assisted Internal Fixation (SAIF) might represent a minimally invasive option to obtain VB reconstruction and restoration of axial load capability in severe osteoporotic and neoplastic fractures, potentially obviating the need for more invasive surgical interventions in situations that would pose significant challenges to standard vertebroplasty or balloon kyphoplasty.

Study design A retrospective analysis of a single-center consecutive series of patients. Objective To test the hypothesis that using a mobile intraoperative computed tomography in combination with spinal navigation would result in better accuracy of lateral mass and pedicle screws between C3 and T5 levels, compared to cone-beam computed tomography and traditional 2D fluoroscopy. Summary of background data Use of spinal navigation associated with 3D imaging has been shown to improve accuracy of screw positioning in the cervico-thoracic region. However, use of iCT imaging compared to a cone-beam CT has not been fully investigated in these types of surgical interventions. Methods We retrospectively analyzed a series of patients who underwent posterior cervico-thoracic fixations using different intraoperative imaging systems in a single hospital. We identified three different groups of patients: Group A, operated under 2D-fluoroscopic guidance without navigation; Group B: O-arm guidance with navigation; Group C: iCT AIRO guidance with navigation. Primary outcome was the rate of accurately placed screws, measured on intra or postoperative CT scan with Neo et al. classification for cervical pedicles screws and Gertzbein et al. for thoracic pedicle screws. Screws in cervical lateral masses were evaluated according to a new classification created by the authors. Results Data on 67 patients and 495 screws were available. Overall screw accuracy was 92.8% (95.6% for lateral mass screws, 81.6% for cervical pedicle screws, and 90% for thoracic pedicle screws). Patients operated with iCT AIRO navigation had significantly fewer misplaced screws (2.4%) compared to 2D-fluoroscopic guidance (9.1%) and O-arm navigation (9.7%) (P = 0.0152). Accuracy rate of iCT navigation versus O-arm navigation was significantly higher (P = 0.0042), and there was no statistically significant difference in surgical time between the three Groups (P = 0.5390). Conclusion Use of high-quality CT associated with spinal navigation significantly improved accuracy of screw positioning in the cervico-thoracic region.Level of Evidence: 3.

OBJECTIVESevere lytic cancerous lesions of the spine are associated with significant morbidity and treatment challenges. Stabilization and restoration of the axial load capability of the vertebral body (VB) are important to prevent or arrest vertebral collapse. Percutaneous stent screw–assisted internal fixation (SAIF), which anchors a VB stent/cement complex with pedicular screws to the posterior vertebral elements, is a minimally invasive, image-guided, 360° internal fixation technique that can be utilized in this patient cohort. The purpose of this study was to assess the feasibility, safety, and stabilization efficacy of VB reconstruction via the SAIF technique in a cohort of patients with extensive lytic vertebral lesions, who were considered to have an unstable or potentially unstable spine according to the Spinal Instability Neoplastic Score (SINS).METHODSThis study was a retrospective assessment of a prospectively maintained database of a consecutive series of patients with neoplastic extensive extracompartmental osteolysis (Tomita type 4–6) of the VB treated with the SAIF technique. VB reconstruction was assessed on postprocedure plain radiographs and CT by two independent raters. Technical and clinical complications were recorded. Clinical and imaging follow-ups were assessed.RESULTSThirty-five patients with extensive osteolytic metastatic lesions of the VB underwent 36 SAIF procedures. SAIF was performed as a stand-alone procedure in 31/36 cases and was associated with posterior surgical fixation in 5/36 (4/5 with decompressive laminectomy). In 1 case an epidural cement leak required surgical decompression. VB reconstruction was categorized as satisfactory (excellent or good rating) by the two raters in 34/36 cases (94.5%) with an interrater reliability of 94.4% (Cohen’s kappa of 0.8). Follow-up, ranging from 1 to 30 months, was available for 30/36 levels. Long-term follow-up (6–30 months, mean 11.5 months) was available for 16/36 levels. Stability during follow-up was noted in 29/30 cases.CONCLUSIONSSAIF provides 360° nonfusion internal fixation that stabilizes the VB in patients with extensive lytic lesions that would otherwise be challenging to treat.

BackgroundExtensive lytic lesions of the vertebral body (VB) increase risk of fracture and instability and require stabilization of the anterior column. Vertebral augmentation is an accepted treatment option, but when osteolysis has extensively destroyed the VB cortical boundaries (a condition herein defined as ‘extreme osteolysis’), the risk of cement leakage and/or insufficient filling is high. Vertebral body stents (VBSs) might allow partial restoration of VB height, cement containment, and reinforcement, but their use in extreme osteolysis has not been investigated.ObjectiveTo assess retrospectively the feasibility and safety of VBS augmentation in patients with ‘extreme osteolysis’ of the VB.MethodsWe retrospectively analyzed 41 treated vertebrae (from T1 to L5). VB reconstruction was assessed on postprocedure CT images and rated on a qualitative 4-point scale (poor-fair-good-excellent). Clinical and radiological follow-up was performed at 1 month and thereafter at intervals in accordance with oncological protocols.ResultsVBS augmentation was performed at 12 lumbar and 29 thoracic levels, with bilateral VBS in 23/41. VB reconstruction was judged satisfactory (good or excellent) in 37/41 (90%) of levels. Bilateral VBS received higher scores than unilateral (p=0.057, Pearson’s X2). We observed no periprocedural complications. Cement leaks (epidural or foraminal) occurred at 5/41 levels (12.2%) without clinical consequences. Follow-up data were available for 27/29 patients, extending beyond 6 months for 20 patients (7–28 months, mean 15.3 months). VBS implant stability was observed in 40/41 cases (97.5%).ConclusionsOur results support the use of VBS as a minimally invasive, safe and effective option for reconstructing the anterior column in prominent VB osteolysis.

OBJECTIVENavigation-enabling technology such as 3D-platform (O-arm) or intraoperative mobile CT (iCT-Airo) systems for use in spinal surgery has considerably improved accuracy over that of traditional fluoroscopy-guided techniques during pedicular screw positioning. In this study, the authors compared 2 intraoperative imaging systems with navigation, available in their neurosurgical unit, in terms of the accuracy they provided for transpedicular screw fixation in the thoracic and lumbar spine.METHODSThe authors performed a retrospective analysis of clinical and surgical data of 263 consecutive patients who underwent thoracic and lumbar spine screw placement in the same center. Data on 97 patients who underwent surgery with iCT-Airo navigation (iCT-Airo group) and 166 with O-arm navigation (O-arm group) were analyzed. Most patients underwent surgery for a degenerative or traumatic condition that involved thoracic and lumbar pedicle screw fixation using an open or percutaneous technique. The primary endpoint was the proportion of patients with at least 1 screw not correctly positioned according to the last intraoperative image. Secondary endpoints were the proportion of screws that were repositioned during surgery, the proportion of patients with a postoperative complication related to screw malposition, surgical time, and radiation exposure. A blinded radiologist graded screw positions in the last intraoperative image according to the Heary classification (grade 1–3 screws were considered correctly placed).RESULTSA total of 1361 screws placed in 97 patients in the iCT-Airo group (503 screws) and in 166 in the O-arm group (858 screws) were graded. Of those screws, 3 (0.6%) in the iCT-Airo group and 4 (0.5%) in the O-arm group were misplaced. No statistically significant difference in final accuracy between these 2 groups or in the subpopulation of patients who underwent percutaneous surgery was found. Three patients in the iCT-Airo group (3.1%, 95% CI 0%–6.9%) and 3 in the O-arm group (1.8%, 95% CI 0%–4.0%) had a misplaced screw (Heary grade 4 or 5). Seven (1.4%) screws in the iCT-Airo group and 37 (4.3%) in the O-arm group were repositioned intraoperatively (p = 0.003). One patient in the iCT-Airo group and 2 in the O-arm group experienced postoperative neurological deficits related to hardware malposition. The mean surgical times in both groups were similar (276 [iCT-Airo] and 279 [O-arm] minutes). The mean exposure to radiation in the iCT-Airo group was significantly lower than that in the O-arm group (15.82 vs 19.12 mSv, respectively; p = 0.02).CONCLUSIONSIntroduction of a mobile CT scanner reduced the rate of screw repositioning, which enhanced patient safety and diminished radiation exposure for patients, but it did not improve overall accuracy compared to that of a mobile 3D platform.

Objective A new stent-screw−assisted internal fixation (SAIF) minimally invasive cement-augmentation technique has been introduced to treat patients with extreme osteolytic lesions of the vertebral body. The aim of the current finite element study, employing a spine model with an extreme osteolytic defect, was to assess the effect of the SAIF technique in reducing strains in the vertebral body in comparison with a standard surgical short posterior fixation. Methods Different finite element models of a L1−S1 spine were developed, representing an intact condition (reference configuration), an extreme osteolysis condition, and its treatment, respectively with stand-alone SAIF, SAIF and posterior fixation, and with stand-alone posterior fixation. Each model was loaded to reproduce standing and upper body bending. Principal strains were calculated on the superior endplate, anterior and posterior cortical walls. A paired Wilcoxon test with a 0.05 significance level was performed to statistically analyze the results. Results Median strains on the bony structures increased in the osteolysis model compared with the intact model, and the SAIF technique was effective in reducing such strains under both standing and flexion conditions. Additional posterior fixation, combined with the SAIF technique, produced minimal further reduction of the median strains on the bony structures. Stand-alone posterior fixation only shielded the osteolytic vertebra avoiding excessive displacements but failed in restoring the axial stiffness to values typical of the intact vertebra. Conclusions The new SAIF technique resulted effective in restoring the load-bearing capacity of the extensively osteolytic vertebra; additional posterior fixation provided only further minor advantages.

BACKGROUND AND PURPOSE: Postgadolinium MR imaging is crucial for brain tumor diagnosis and morphometric assessment. We compared brain tumor enhancement visualization and the “target” object morphometry obtained with the most commonly used 3D MR imaging technique, MPRAGE, with 2 other routinely available techniques: sampling perfection with application-optimized contrasts by using different flip angle evolutions (SPACE) and volumetric interpolated brain examination (VIBE). MATERIALS AND METHODS: Fifty-four contrast-enhancing tumors (38 gliomas and 16 metastases) were assessed using MPRAGE, VIBE, and SPACE techniques randomly acquired after gadolinium-based contrast agent administration on a 3T scanner. Enhancement conspicuity was assessed quantitatively by calculating the contrast rate and contrast-to-noise ratio, and qualitatively, by consensus visual comparative ratings. The total enhancing tumor volume and between-sequence discrepancy in the margin delineation were assessed on the corresponding 3D target objects contoured with a computer-assisted software for neuronavigation. The Wilcoxon signed rank and Pearson χ(2) nonparametric tests were used to investigate between-sequence discrepancies in the contrast rate, contrast-to-noise ratio, visual conspicuity ratings, tumor volume, and margin delineation estimates. Differences were also tested for 1D (Response Evaluation Criteria in Solid Tumors) and 2D (Response Assessment in Neuro-Oncology) measurements. RESULTS: Compared with MPRAGE, both SPACE and VIBE obtained higher contrast rate, contrast-to-noise ratio, and visual conspicuity ratings in both gliomas and metastases (P range

A wide spectrum of conditions may compress the spinal cord: degenerative disease, disc herniation and neoplasms are the most common causes; other conditions include trauma, epidural abscess and hematoma. The role of imaging is to establish a radiological diagnosis, to distinguish intrinsic spinal cord disease from extrinsic compression, to define mechanical spine stability and to evaluate the integrity of neural tissue. Clinical presentation, variable in severity and patterns of progression, influences the imaging approach. Imaging is required to assess osseous structures and soft tissues. The need to image 'across anatomical compartments' usually requires more than one imaging technique. Multidetector CT is the first-line imaging modality in acute spine trauma. MRI is the best imaging modality to assess soft tissues, image the extradural, intradural and spinal cord compartments. MRI needs to be implemented with fat-suppression techniques applied to T2- and contrast-enhanced T1-weighted sequences. MRI hel...

This short review focuses on clinical and therapeutic issues posed by severe osteoporotic and neoplastic insufficiency vertebral fractures and on the potential use of a new technique to obtain minimally invasive vertebral body reconstruction, augmentation, and stabilization in such severe fractures, combining two preexisting procedures. The implant of vertebral body stents is followed by insertion of percutaneous, fenestrated, cement-augmented pedicular screws that act as anchors to the posterior elements for the cement&ndash, stent complex. This procedure results in a 360&deg, nonfusion form of vertebral internal fixation that may empower vertebral augmentation and potentially avoid corpectomy in challenging osteoporotic and neoplastic fractures.

Incidental extra-mammary findings in breast Magnetic Resonance Imaging (MRI) may be benign in nature, but may also represent a metastasis or another important lesion. We aimed to analyse the prevalence and clinical relevance of these unexpected findings. A retrospective review of 1535 breast MRIs was conducted. Only axial sequences were reassessed. Confirmation examinations were obtained in all cases. 285 patients had a confirmed incidental finding, which were located in the liver (51.9%), lung (11.2%), bone (7%), mediastinal lymph nodes (4.2%) or consisted of pleural/pericardial effusion (15.4%). 20.4% of incidental findings were confirmed to be malignant. Positive predictive value for MRI to detect a metastatic lesion was high if located within the bone (89%), lymph nodes (83%) and lung (59%), while it was low if located within the liver (9%) or if it consisted of pleural/pericardial effusion (6%). The axial enhanced sequence showed superior sensitivity to unenhanced images in detecting metastatic lesions, especially if only smaller (≤10 mm.) lesions were considered. The prevalence of metastatic incidental extra-mammary findings is not negligible. Particular attention should be to incidental findings located within the lung, bone and mediastinal lymph nodes.

Background It has been ascertained that triple-negative (TN) breast cancer is characterized by an aggressive clinical course and a poor prognosis. The purpose of our study was to compare the magnetic resonance imaging (MRI) features of the 3 major different breast cancer subtypes (TN, luminal, and human epidermal growth factor receptor 2 [HER2]-overexpressing) and to suggest the criteria that might predict TN phenotype. Materials and Methods From October 2007 to April 2011, we studied 77 patients with histologically confirmed TN breast cancer who underwent breast MRI. We randomly included 148 patients with non-TN breast cancer (110 luminal and 38 HER-overexpressing) as a control group. We evaluated the clinicopathologic data, the MRI morphologic and kinetic features, the signal intensity on T2-weighted images, and the apparent diffusion coefficient (ADC). Results Our results confirmed that TN tumors are more aggressive, are usually diagnosed at a younger age compared with the other study groups, and show benign morphologic features with MRI. Backward stepwise logistic regression identified some parameters as independent predictors of TN-type lesions: age, size, shape, presence of edema, and infiltrative characteristics. The receiver operating characteristic (ROC) curve, built with 4 of 5 these factors as criteria to predict TN status, showed a 0.664 area under the curve (AUC) value (sensitivity 58.4%, specificity 73.2%). The inclusion of the fifth criterion showed a 0.699 AUC value (sensitivity, 49.4%; specificity, 89.4%). Conclusion We identified the clinicoradiologic parameters that are independent predictors of TN breast lesions, which might be helpful for earlier prediction of the TN status of a breast lesion.

Background context Percutaneous vertebroplasty (PV) can provide pain relief and biomechanical stabilization of lytic metastasis of the spine in selected patients. Percutaneous vertebroplasty of the atlas has been reported in only five cases and has been performed with different techniques and approaches. Purpose To describe the technique we used to perform PV of a lytic lesion of the lateral mass of C1 under computed tomography, computed tomography angiography, and computed tomography fluoroscopy guidance with a posterolateral approach, sparing the vertebral artery (VA). Study design/setting Technical note. Methods A 36-year-old woman with a history of intestinal carcinoid tumor presented with neck pain refractory to medical treatment. Radiological evaluation showed osteolytic destruction of the left lateral mass of the atlas, at the risk of collapse, with erosion of the VA canal. Under computed tomography and computed tomography angiography guidance, a percutaneous posterolateral oblique approach to the C1 left lateral mass was performed followed by cement augmentation under computed tomography fluoroscopy control. Results Complete cement filling of the osteolytic lesion was achieved. A cement leak was noted along the horizontal V3 segment of the left VA. Computed tomography angiography scan showed patency of the VA after the procedure. There were no clinical complications. The patient reported substantial pain relief and improved range of motion at 12 hours postprocedure, which remained stable at 2-month follow-up examination. Conclusions Computed tomography–guided PV of C1 lytic lesion with posterolateral approach was effective in the described case for pain control and stabilization, and it may be a therapeutic option in selected patients to avoid occipitocervical fusion. This procedure requires good understanding of the anatomy and rigorous technique to avoid potential complications.