Short-Term Neck Pain After Posterior Foraminotomy Compared with Anterior Discectomy with Fusion for Cervical Foraminal Radiculopathy: A Secondary Analysis of the FACET Randomized Controlled Trial.

BACKGROUND: Short-term neck pain after posterior cervical foraminotomy (posterior surgery) compared with anterior cervical discectomy with fusion (anterior surgery) treating cervical radiculopathy has only been assessed once, retrospectively, to our knowledge. The aim of this study was to prospectively evaluate the course of neck pain for 6 weeks after both treatments. METHODS: This is a secondary analysis of the multicenter Foraminotomy ACDF Cost-Effectiveness Trial (FACET), conducted from January 2016 to May 2020. Of 389 patients who had single-level, 1-sided cervical radiculopathy and were screened for eligibility, 265 were randomly assigned to undergo posterior surgery (n = 132) or anterior surgery (n = 133). The primary outcome of the present analysis was neck pain, assessed weekly for 6 weeks using the visual analog scale (VAS), on a scale of 0 to 100. The secondary outcomes were arm pain, neck disability, work ability, quality of life, treatment satisfaction, motor and sensory changes, and hospital length of stay. Data were analyzed with mixed model analysis in intention-to-treat samples using 2-sided 95% confidence intervals (CIs). RESULTS: In the first postoperative week, the mean VAS for neck pain was 56.2 mm (95% CI, 51.7 to 60.8 mm) after posterior surgery and 46.7 mm (95% CI, 42.2 to 51.2 mm) after anterior surgery. The mean between-group difference was 9.5 mm (95% CI, 3.3 to 15.7 mm), which gradually decreased to 2.3 mm (95% CI, -3.6 to 8.1 mm) at postoperative week 6. As of postoperative week 5, there was no significant difference between groups. Responder analyses confirmed this result. Secondary outcomes showed small differences between groups. CONCLUSIONS: Insight into the course of neck pain during the first 6 weeks after posterior compared with anterior surgery is provided. Despite initially more neck pain after posterior surgery, patients swiftly improved and, as of postoperative week 5, results similar to those after anterior surgery were observed. Our findings should enable improved patient counseling and enhanced shared decision-making between physicians and patients with cervical radiculopathy, where more neck pain in the first postoperative weeks should be balanced against the benefits of posterior surgery. LEVEL OF EVIDENCE: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

Noninferiority of Posterior Cervical Foraminotomy vs Anterior Cervical Discectomy With Fusion for Procedural Success and Reduction in Arm Pain Among Patients With Cervical Radiculopathy at 1 Year: The FACET Randomized Clinical Trial.

Importance: The choice between posterior cervical foraminotomy (posterior surgery) and anterior cervical discectomy with fusion (anterior surgery) for cervical foraminal radiculopathy remains controversial. Objective: To investigate the noninferiority of posterior vs anterior surgery in patients with cervical foraminal radiculopathy with regard to clinical outcomes after 1 year. Design, Setting, and Participants: This multicenter investigator-blinded noninferiority randomized clinical trial was conducted from January 2016 to May 2020 with a total follow-up of 2 years. Patients were included from 9 hospitals in the Netherlands. Of 389 adult patients with 1-sided single-level cervical foraminal radiculopathy screened for eligibility, 124 declined to participate or did not meet eligibility criteria. Patients with pure axial neck pain without radicular pain were not eligible. Of 265 patients randomized (132 to posterior and 133 to anterior), 15 were lost to follow-up and 228 were included in the 1-year analysis (110 in posterior and 118 in anterior). Interventions: Patients were randomly assigned 1:1 to posterior foraminotomy or anterior cervical discectomy with fusion. Main Outcomes and Measures: Primary outcomes were proportion of success using Odom criteria and decrease in arm pain using a visual analogue scale from 0 to 100 with a noninferiority margin of 10% (assuming advantages with posterior surgery over anterior surgery that would justify a tolerable loss of efficacy of 10%). Secondary outcomes were neck pain, disability, quality of life, work status, treatment satisfaction, reoperations, and complications. Analyses were performed with 2-proportion z tests at 1-sided .05 significance levels with Bonferroni corrections. Results: Among 265 included patients, the mean (SD) age was 51.2 (8.3) years; 133 patients (50%) were female and 132 (50%) were male. Patients were randomly assigned to posterior (132) or anterior (133) surgery. The proportion of success was 0.88 (86 of 98) in the posterior surgery group and 0.76 (81 of 106) in the anterior surgery group (difference, -0.11 percentage points; 1-sided 95% CI, -0.01) and the between-group difference in arm pain was -2.8 (1-sided 95% CI, -9.4) at 1-year follow-up, indicating noninferiority of posterior surgery. Decrease in arm pain had a between-group difference of 3.4 (1-sided 95% CI, 11.8), crossing the noninferiority margin with 1.8 points. All secondary outcomes had 2-sided 95% CIs clustered around 0 with small between-group differences. Conclusions and Relevance: In this randomized clinical trial, posterior surgery was noninferior to anterior surgery for patients with cervical radiculopathy regarding success rate and arm pain at 1 year. Decrease in arm pain and secondary outcomes had small between-group differences. These results may be used to enhance shared decision-making. Trial Registration: Netherlands Trial Register Identifier: NTR5536.

The Accuracy of Patient-Specific Spinal Drill Guides Is Non-Inferior to Computer-Assisted Surgery: The Results of a Split-Spine Randomized Controlled Trial.

In recent years, patient-specific spinal drill guides (3DPGs) have gained widespread popularity. Several studies have shown that the accuracy of screw insertion with these guides is superior to that obtained using the freehand insertion technique, but there are no studies that make a comparison with computer-assisted surgery (CAS). The aim of this study was to determine whether the accuracy of insertion of spinal screws using 3DPGs is non-inferior to insertion via CAS. A randomized controlled split-spine study was performed in which 3DPG and CAS were randomly assigned to the left or right sides of the spines of patients undergoing fixation surgery. The 3D measured accuracy of screw insertion was the primary study outcome parameter. Sixty screws inserted in 10 patients who completed the study protocol were used for the non-inferiority analysis. The non-inferiority of 3DPG was demonstrated for entry-point accuracy, as the upper margin of the 95% CI (−1.01 mm−0.49 mm) for the difference between the means did not cross the predetermined non-inferiority margin of 1 mm (p < 0.05). We also demonstrated non-inferiority of 3D angular accuracy (p < 0.05), with a 95% CI for the true difference of −2.30°−1.35°, not crossing the predetermined non-inferiority margin of 3° (p < 0.05). The results of this randomized controlled trial (RCT) showed that 3DPGs provide a non-inferior alternative to CAS in terms of screw insertion accuracy and have considerable potential as a navigational technique in spinal fixation.

Fluorescence-guided detection of pituitary neuroendocrine tumor (PitNET) tissue during endoscopic transsphenoidal surgery available agents, their potential, and technical aspects.

Differentiation of pituitary neuroendocrine tumor (PitNET) tissue from surrounding normal tissue during surgery is challenging. A number of fluorescent agents is available for visualization of tissue discrepancy, with the potential of improving total tumor resection. This review evaluates the availability, clinical and technical applicability of the various fluorescent agents within the field of pituitary surgery. According to PRISMA guidelines, a systematic review was performed to identify reports describing results of in vivo application of fluorescent agents. In this review, 15 publications were included. Sodium Fluorescein (FNa) was considered in two studies. The first study reported noticeable fluorescence in adenoma tissue, the second demonstrated the strongest fluorescence in non-functioning pituitary adenomas. 5-Aminolevulinic acid (5-ALA) was investigated in three studies. One study compared laser-based optical biopsy system (OBS) with photo-diagnostic filter (PD) and found that the OBS was able to detect all microadenomas, even when MRI was negative. The second study retrospectively analyzed twelve pituitary adenomas and found only one positive for fluorescence. The third investigated fifteen pituitary adenomas of which one displayed vague fluorescence. Indocyanine green (ICG) was researched in four studies with variable results. Second-Window ICG yielded no significant difference between functioning and non-functioning adenomas in one study, while a second study displayed 4 times higher fluorescence in tumor tissue than in normal tissue. In three studies, OTL38 showed potential in non-functioning pituitary adenomas. At present, evidence for fluorescent agents to benefit total resection of PitNETs is lacking. OTL38 can potentially serve as a selective fluorescent agent in non-functioning pituitary adenomas in the near future.

A Comparison of Drill Guiding and Screw Guiding 3D-Printing Techniques for Intra- and Extrapedicular Screw Insertion.

STUDY DESIGN: Screw randomized cadaveric study. OBJECTIVE: To compare the accuracy of three-dimensional (3D)-printed drill guides versus additional screw guiding techniques for challenging intra- and extrapedicular screw trajectories. SUMMARY OF BACKGROUND DATA: Pedicle screw placement can be technically demanding, especially in syndromic scoliosis with limited bone stock. Recently, 3D-printing and virtual planning technology have become available as new tools to improve pedicle screw insertion. Differences in techniques exist, while some focus on guiding the drill, others also actively guide subsequent screws insertion. The accuracy of various 3D-printing-assisted techniques has been studied; however, direct comparative studies have yet to determine whether there is a benefit of additional screw guidance. METHODS: Two cadaveric experiments were conducted to compare drill guides with two techniques that introduce additional screw guiding. The screw guiding consisted of either k-wire cannulated screws or modular guides, which were designed to guide the screw in addition to the drill bit. Screws were inserted intra- or extrapedicular using one of each methods according to a randomization scheme. Postoperative computed tomography scanning was performed and fused with the preoperative planning for detailed 3D screw deviation analysis. RESULTS: For intrapedicular screw trajectories malpositioning was low (2%) and the modular guides revealed a statistically significant increase of accuracy (P  = 0.05) compared with drill guides. All techniques showed accurate cervical screw insertion without breach. For the extrapedicular screw trajectories both additional screw guiding methods did not significantly (P = 0.09) improve accuracy and malpositioning rates remained high (24%). CONCLUSIONS: In this cadaveric study it was found that the additional screw-guiding techniques are not superior to the regular 3D-printed drill guides for the technically demanding extrapedicular screw technique. For intrapedicular screw insertion, modular guides can improve insertion; however, at cervical levels regular 3D-printed drill guides already demonstrated very high accuracy and therefore there is no benefit from additional screw guiding techniques. LEVEL OF EVIDENCE: 3.

An aggressive poorly differentiated plurihormonal Pit-1-positive adenoma.

SUMMARY: In July 2017, a 35-year-old woman was referred to our care for treatment of a large pituitary mass with an unusually high growth rate. She presented with right-sided ptosis and diplopia (n. III palsy), increasing retrobulbar pain and vertigo. Although laboratory investigations were consistent with acromegaly, she exhibited no clear phenotypic traits. During transsphenoidal surgery aimed at biopsy, typical adenomatous tissue was encountered, upon which it was decided to proceed to debulking. Histopathological analysis demonstrated a poorly differentiated plurihormonal Pit-1-positive adenoma with focal growth hormone (GH) and prolactin positivity, positive SSTR2 staining and a Ki-67 of 20-30%. Postoperative magnetic resonance imaging (MRI) examination revealed a large tumour remnant within the sella invading the right cavernous sinus with total encasement of the internal carotid artery and displacement of the right temporal lobe. As a consequence, she was treated additionally with radiotherapy, and a long-acting first-generation somatostatin analogue was prescribed. Subsequently, the patient developed secondary hypocortisolism and diabetes mellitus despite adequate suppression of GH levels. In September 2019, her symptoms recurred. Laboratory evaluations indicated a notable loss of biochemical control, and MRI revealed tumour progression. Lanreotide was switched to pasireotide, and successful removal of the tumour remnant and decompression of the right optic nerve was performed. She received adjuvant treatment with temozolomide resulting in excellent biochemical and radiological response after three and six courses. Symptoms of right-sided ptosis and diplopia remained. Evidence for systemic therapy in case of tumour progression after temozolomide is currently limited, although various potential targets can be identified in tumour tissue. LEARNING POINTS: Poorly differentiated plurihormonal Pit-1-positive adenoma is a potentially aggressive subtype of pituitary tumours. This subtype can express somatostatin receptors, allowing treatment with somatostatin analogues. A multidisciplinary approach involving an endocrinologist, neurosurgeon, pituitary pathologist, neuroradiologist, radiation oncologist and medical oncologist is key for the management of patients with aggressive pituitary tumours, allowing the successful application of multimodality treatment. Temozolomide is first-line chemotherapy for aggressive pituitary tumours and carcinomas. Further development of novel targeted therapies, such as peptide receptor radionuclide therapy (PRRT), vascular endothelial growth factor (VEGF) receptor-targeted therapy, tyrosine kinase inhibitors, mammalian target of rapamycin (mTOR) inhibitors and immune checkpoint inhibitors, is needed.

Detection by fluorescence of pituitary neuroendocrine tumour (PitNET) tissue during endoscopic transsphenoidal surgery using bevacizumab-800CW (DEPARTURE trial): study protocol for a non-randomised, non-blinded, single centre, feasibility and dose-finding trial.

INTRODUCTION: Achieving gross total resection and endocrine remission in pituitary neuroendocrine tumours (PitNET) can be challenging, especially in PitNETs with cavernous sinus (CS) invasion, defined as a Knosp grade of 3 or 4. A potential target to identify PitNET tissue is vascular endothelial growth factor A (VEGF-A), which expression is known to be significantly higher in PitNETs with CS invasion. METHODS AND ANALYSIS: The aim of this non-randomised, non-blinded, single centre, feasibility and dose-finding phase 1 trial is to determine the feasibility of intraoperative fluorescence imaging detection of PitNET tissue during endoscopic transsphenoidal surgery using the VEGF-A targeting optical agent bevacizumab-800CW (4, 5, 10 or 25 mg). Nine to fifteen patients with a PitNET with a Knosp grade of 3 or 4 will be included. Secondary objectives are: (1) To identify the optimal tracer dose for imaging of PitNET tissue during transsphenoidal surgery for further development in a phase 2 fluorescence molecular endoscopy trial. (2) To quantify fluorescence intensity in vivo and ex vivo with multidiameter single-fibre reflectance, single-fibre fluorescence (MDSFR/SFF) spectroscopy. (3) To correlate and validate both the in vivo and ex vivo measured fluorescence signals with histopathological analysis and immunohistochemical staining. (4) To assess the (sub)cellular location of bevacizumab-800CW by ex vivo fluorescence microscopy. Intraoperative, three imaging moments are defined to detect the fluorescent signal. The tumour-to-background ratios are defined by intraoperative fluorescence in vivo measurements including MDSFR/SFF spectroscopy data and by ex vivo back-table fluorescence imaging. After inclusion of three patients in each dose group, an interim analysis will be performed to define the optimal dose. ETHICS AND DISSEMINATION: Approval was obtained from the Medical Ethics Review Board of the University Medical Centre Groningen. Results will be disseminated through national and international journals. The participants and relevant patient support groups will be informed about the results. TRIAL REGISTRATION NUMBER: NCT04212793.

A semi-automatic seed point-based method for separation of individual vertebrae in 3D surface meshes: a proof of principle study.

PURPOSE: The purpose of this paper is to present and validate a new semi-automated 3D surface mesh segmentation approach that optimizes the laborious individual human vertebrae separation in the spinal virtual surgical planning workflow and make a direct accuracy and segmentation time comparison with current standard segmentation method. METHODS: The proposed semi-automatic method uses the 3D bone surface derived from CT image data for seed point-based 3D mesh partitioning. The accuracy of the proposed method was evaluated on a representative patient dataset. In addition, the influence of the number of used seed points was studied. The investigators analyzed whether there was a reduction in segmentation time when compared to manual segmentation. Surface-to-surface accuracy measurements were applied to assess the concordance with the manual segmentation. RESULTS: The results demonstrated a statically significant reduction in segmentation time, while maintaining a high accuracy compared to the manual segmentation. A considerably smaller error was found when increasing the number of seed points. Anatomical regions that include articulating areas tend to show the highest errors, while the posterior laminar surface yielded an almost negligible error. CONCLUSION: A novel seed point initiated surface based segmentation method for the laborious individual human vertebrae separation was presented. This proof-of-principle study demonstrated the accuracy of the proposed method on a clinical CT image dataset and its feasibility for spinal virtual surgical planning applications.

Three-Dimensional-Printed Drill Guides for Occipitothoracic Fusion in a Pediatric Patient With Occipitocervical Instability.

BACKGROUND: Pediatric occipitothoracic fusion can be challenging because of small size pedicles and thin occipital bone. Three-dimensional (3D) printing technology can help with accurate screw insertion but has not been described for occipital keel plate positioning so far. OBJECTIVE: To describe the novel use of 3D technology to position occipital keel plates during pediatric occipitothoracic fixation. METHODS: A young boy with segmental spinal dysgenesis presented with asymmetrical pyramidal paresis in all limbs. Developmental abnormities of the cervical spine caused a thinned spinal cord, and because of progressive spinal cord compression, surgical intervention by means of occipitothoracic fixation was indicated at the age of 3 yr.Because of the small-size pedicles and thin occipital bone, the pedicle screws and occipital plates were planned meticulously using 3D virtual surgical planning technology. The rods were virtually bent in order to properly align with the planned screws. By means of 3D-printed guides, the surgical plan was transferred to the operating theater. For the occipital bone, a novel guide concept was developed, aiming for screw positions at maximal bone thickness. RESULTS: The postoperative course was uneventful, and radiographs showed good cervical alignment. After superimposing the virtual plan with the intraoperative acquired computed tomography, it was confirmed that the occipital plate positions matched the virtual plan and that pedicle screws were accurately inserted without signs of breach. CONCLUSION: The use of 3D technology has greatly facilitated the performance of the occipitothoracic fixation and could, in the future, contribute to safer pediatric spinal fixation procedures.

Accuracy of Patient-Specific 3D-Printed Drill Guides for Pedicle and Lateral Mass Screw Insertion: An Analysis of 76 Cervical and Thoracic Screw Trajectories.

STUDY DESIGN: Single-center retrospective case series. OBJECTIVE: The purpose of this study was to assess the safety and accuracy of three-dimensional (3D)-printed individualized drill guides for pedicle and lateral mass screw insertion in the cervical and upper-thoracic region, by comparing the preoperative 3D surgical plan with the postoperative results. SUMMARY OF BACKGROUND DATA: Posterior spinal fusion surgery can provide rigid intervertebral fixation but screw misplacement involves a high risk of neurovascular injury. However, modern spine surgeons now have tools such as virtual surgical planning and 3D-printed drill guides to facilitate spinal screw insertion. METHODS: A total of 15 patients who underwent posterior spinal fusion surgery involving patient-specific 3D-printed drill guides were included in this study. After segmentation of bone and screws, the postoperative models were superimposed onto the preoperative surgical plan. The accuracy of the realized screw trajectories was quantified by measuring the entry point and angular deviation. RESULTS: The 3D deviation analysis showed that the entry point and angular deviation over all 76 screw trajectories were 1.40 ±â€Š0.81 mm and 6.70 ±â€Š3.77°, respectively. Angular deviation was significantly higher in the sagittal plane than in the axial plane (P = 0.02). All screw positions were classified as "safe" (100%), showing no neurovascular injury, facet joint violation, or violation of the pedicle wall. CONCLUSIONS: 3D virtual planning and 3D-printed patient-specific drill guides appear to be safe and accurate for pedicle and lateral mass screw insertion in the cervical and upper-thoracic spine. The quantitative 3D deviation analyses confirmed that screw positions were accurate with respect to the 3D-surgical plan.Level of Evidence: 4.

Surgical Interventions for Cervical Radiculopathy without Myelopathy: A Systematic Review and Meta-Analysis.

BACKGROUND: The effectiveness of surgical interventions for cervical degenerative disorders has been investigated in multiple systematic reviews. Differences in study population (e.g., patients with myelopathy and/or radiculopathy) were often neglected. Therefore, the objective of this study was to investigate the effectiveness of surgical interventions for patients with symptoms of cervical radiculopathy without myelopathy by conducting a systematic review and meta-analysis based on randomized controlled trials (RCTs). METHODS: A comprehensive systematic search was conducted in MEDLINE, Embase, and CENTRAL (Cochrane Central Register of Controlled Trials) to identify RCTs that investigated the effectiveness of surgical interventions using an anterior or posterior approach compared with other interventions for patients with pure cervical radiculopathy. Outcomes were success rates (Odom criteria, similar rating scales, or percentage of patients who improved), complication and reoperation rates, work status, disability (Neck Disability Index), and pain (arm and neck). The Cochrane risk-of-bias tool was used to assess the likelihood of the risk of bias. A random-effects model was used. Heterogeneity among study results (I2 ≥ 50% or p < 0.05) was explored by conducting subgroup analyses. Funnel plots were used to assess the likelihood of publication bias. RESULTS: A total of 21 RCTs were included, comprising 1,567 patients. For all outcomes, among all surgical techniques, only 1 pooled estimate showed a significant effect on success rate, which was in favor of anterior cervical discectomy with fusion compared with anterior cervical discectomy without an intervertebral spacer (p = 0.02; risk ratio [RR] = 0.87; 95% confidence interval [CI] = 0.77 to 0.98). Complication rates were higher when autologous bone graft from the iliac crest was used as an intervertebral spacer (p < 0.01; RR = 3.40; 95% CI = 1.56 to 7.43), related to donor-site morbidity. CONCLUSIONS: This meta-analysis demonstrated consistent results regarding clinical outcome for pure cervical radiculopathy among all studied interventions. Complication and reoperation rates were also similar, with the exception of higher complication rates in patients in whom autologous bone grafts were used. On the basis of clinical outcome and safety, there is no superior surgical intervention for pure cervical radiculopathy. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

The Odom Criteria: Validated at Last: A Clinimetric Evaluation in Cervical Spine Surgery.

BACKGROUND: The Odom criteria, established in 1958, are a widely used, 4-point rating scale for assessing the clinical outcome after cervical spine surgery. Surprisingly, the Odom criteria have never been validated, to our knowledge. The aim of this study was to investigate the reliability and validity of the Odom criteria for the evaluation of surgical procedures of the cervical spine. METHODS: Patients with degenerative cervical spine disease were included in the study and divided into 2 subgroups on the basis of their most predominant symptom: myelopathy or radiculopathy. Reliability was assessed with interrater and test-retest design using quadratic weighted kappa coefficients. Construct validity was assessed by means of hypotheses testing. To evaluate whether the Odom criteria could act as a global perceived effect (GPE) scale, we assessed concurrent validity by comparing area under the curve (AUC) values of receiver operating characteristic (ROC) curves for the set of questionnaires. RESULTS: A total of 110 patients were included in the study; 19 were excluded, leaving 91 in our analysis. Reliability assessments showed κ = 0.77 for overall interrater reliability and κ = 0.93 for overall test-retest reliability. Interrater reliability was κ = 0.81 for the radiculopathy subgroup and κ = 0.68 for the myelopathy subgroup. At least 75% of the hypotheses were met. The AUCs showed similar characteristics between the Odom criteria and GPE scale. CONCLUSIONS: The Odom criteria met the predefined criteria for reliability and validity. Therefore, the Odom criteria may be used to assess surgical outcome after a cervical spine procedure, specifically for patients presenting with radicular symptoms. The results of previous studies that have been deemed less trustworthy because of the use of the Odom criteria should be reconsidered.

Three-Dimensional Printed Polymethylmethacrylate Casting Molds for Posterior Fossa Reconstruction in the Surgical Treatment of Chiari I Malformation: Technical Note and Illustrative Cases.

OBJECTIVE: To describe a new method for cranial reconstruction after posterior fossa craniectomy in the surgical treatment of Chiari 1 malformation through a technical note and presentation of 3 illustrative cases. METHODS AND MATERIALS: A virtual surgical planning workflow was established for planning posterior fossa decompression, designing the suboccipital reconstruction, and manufacturing a 3D-printed polymethylmethacrylate (PMMA) casting mold. The casting accuracy was assessed by conducting a phantom experiment, and clinical data were provided by means of 3 illustrative cases. RESULTS: The accuracy of implant fabrication was found to be excellent, particularly when PMMA is introduced into the mold in a malleable state. In all 3 clinical cases, the implants were fabricated and positioned with success. Postoperative analysis revealed that accurate placement was achieved, with only minor deviation from the preoperative plan. CONCLUSIONS: 3D virtual surgical planning provides feasible tools for the planning of posterior fossa decompression and intraoperative fabrication of accurate patient-specific suboccipital cranioplasty.

Accuracy Assessment of Pedicle and Lateral Mass Screw Insertion Assisted by Customized 3D-Printed Drill Guides: A Human Cadaver Study.

BACKGROUND: Accurate cervical screw insertion is of paramount importance considering the risk of damage to adjacent vital structures. Recent research in 3-dimensional (3D) technology describes the advantage of patient-specific drill guides for accurate screw positioning, but consensus about the optimal guide design and the accuracy is lacking. OBJECTIVE: To find the optimal design and to evaluate the accuracy of individualized 3D-printed drill guides for lateral mass and pedicle screw placement in the cervical and upper thoracic spine. METHODS: Five Thiel-embalmed human cadavers were used for individualized drill-guide planning of 86 screw trajectories in the cervical and upper thoracic spine. Using 3D bone models reconstructed from acquired computed tomography scans, the drill guides were produced for both pedicle and lateral mass screw trajectories. During the study, the initial minimalistic design was refined, resulting in the advanced guide design. Screw trajectories were drilled and the realized trajectories were compared to the planned trajectories using 3D deviation analysis. RESULTS: The overall entry point and 3D angular accuracy were 0.76 ± 0.52 mm and 3.22 ± 2.34°, respectively. Average measurements for the minimalistic guides were 1.20 mm for entry points, 5.61° for the 3D angulation, 2.38° for the 2D axial angulation, and 4.80° for the 2D sagittal angulation. For the advanced guides, the respective measurements were 0.66 mm, 2.72°, 1.26°, and 2.12°, respectively. CONCLUSION: The study ultimately resulted in an advanced guide design including caudally positioned hooks, crosslink support structure, and metal inlays. The novel advanced drill guide design yields excellent drilling accuracy.

Clinical management of spinal metastases-The Dutch national guideline.

This article is a summary of the revised Dutch multidisciplinary evidence-based guideline 'Spinal metastases' (English translation available at: https://www.oncoline.nl/spinal-metastases) that was published at the end of 2015. This summary provides an easy-to-use overview for physicians to use in their daily practice.

Three-Dimensional Planning and Use of Individualized Osteotomy-Guiding Templates for Surgical Correction of Kyphoscoliosis: A Technical Case Report.

OBJECTIVE: We have described the use of 3-dimensional (3D) virtual planning and 3D printed patient-specific osteotomy templates in the surgical correction of a complex spinal deformity. Pedicle subtraction osteotomies (PSOs) for the correction of severe spinal deformities are technically demanding procedures with a risk of major complications. In particular, operations of the severely deformed spine call for new, more precise, methods of surgical planning. The new 3D technology could result in new possibilities for the surgical planning of spinal deformities. METHODS: We present the case of severe congenital kyphoscoliosis in a young girl with skeletal dysplasia. A closing wedge-extended PSO was 3D virtual planned using medical computer design software. After the optimal 3D-wedge procedure was planned, individualized osteotomy-guiding templates were designed for translation of the planned PSO to the surgical procedure. During surgery, the PSO was performed using the osteotomy templates. Successful correction of the kyphoscoliosis was realized. RESULTS: The kyphosis was successfully reduced using a wedge-shaped extended PSO using preoperative 3D virtual planning, assisted by 3D-printed individualized osteotomy-guiding templates. CONCLUSIONS: In addition to direct translation of the planned PSO for surgery, the 3D planning also facilitated a detailed preoperative evaluation, greater insight into the case-specific anatomy, and accurate planning of the required correction.

The Dutch national guideline on metastases and hematological malignancies localized within the spine; a multidisciplinary collaboration towards timely and proactive management.

Here, we describe the development of a Dutch national guideline on metastases and hematological malignancies localized within the spine. The aim was to create a comprehensive guideline focusing on proactive management of these diseases, enabling healthcare professionals to weigh patient perspectives, life expectancy, and expected outcomes to make informed treatment recommendations. A national multidisciplinary panel consisting of clinicians, a nurse, a patient advocate, an epidemiologist, and a methodologist drafted the guideline. The important role of patients in the realization of the guideline enabled us to identify and address perceived shortcomings in patient care. The guideline covers not only metastatic epidural spinal cord compression, but also the treatment of uncomplicated metastases and hematological malignancies localized within the spine. The guideline is applicable in daily practice and provides an up-to-date and concise overview of the diagnostic and treatment possibilities for patients suffering from a disease that can have a serious impact on their quality of life. Suggestions for the practical implementation of patient care in hospitals are also provided, including approaches for pursuing proactive management. The crucial role of the patient in decision making is emphasized in this guideline.

[Alarm symptoms of spinal metastases in patients with cancer]. / Alarmsymptomen van wervelmetastasen bij patiënten met kanker.

Recently, the evidence-based guideline 'Spinal metastasis' produced by the Dutch National Working Group on Neuro-Oncology appeared. This guideline applies to patients with spinal metastases and spinal localizations of haematological malignancies, with or without epidural extension. Timely diagnosis and treatment of spinal metastases is essential in order to reduce pain and neurological deficit in particular. An important aim of this guideline is to reduce both patient and doctor delay by providing information to high-risk patients and their general practitioners and to give clear advice on the organization of care. In this case report we describe two patients with spinal metastases in order to illustrate the difficulties in providing a timely diagnosis and optimal treatment for symptomatic spinal metastases. Furthermore, we provide advice to all health care professionals involved to secure the highest possible quality of life for patients with spinal metastases.

Bilateral versus unilateral interlaminar approach for bilateral decompression in patients with single-level degenerative lumbar spinal stenosis: a multicenter retrospective study of 175 patients on postoperative pain, functional disability, and patient satisfaction.

OBJECT: The bilateral and unilateral interlaminar techniques for bilateral decompression both demonstrate good results for the treatment of degenerative lumbar spinal stenosis (DLSS). Although there is some discussion about which approach is more effective, studies that directly compare these two popular techniques are rare. To address this shortcoming, this study compares postoperative functional disability, pain, and patient satisfaction among patients with single-level DLSS who underwent bilateral decompression using either a bilateral or unilateral approach. METHODS: This retrospective study included patients who underwent operations between November 1, 2009, and October 1, 2011. These patients underwent single-level bilateral decompressive surgery using either the bilateral or unilateral interlaminar approach at one of 5 participating hospitals. Exclusion criteria included previous lumbar surgery, additional disc surgery, and spondylolisthesis requiring fusion surgery. Primary outcome measures included bodily pain (as reported using the visual analog scale [VAS]), the Roland-Morris Disability Questionnaire (RMDQ), and the Oswestry Disability Index (ODI). In addition, reductions in leg and back symptoms and the patient's general evaluation of the procedure were queried. Finally, patient satisfaction and surgical parameters were evaluated. Questionnaires were sent to each patient's home, and electronic patient files were used to collect the data. RESULTS: One hundred and seventy-five patients returned the questionnaire (74.4% response rate; 68 and 107 patients who underwent the bilateral or unilateral approach, respectively). Mean age at surgery was 68 years (range 34-89 years), and the mean follow-up period was 14.2 months (range 3.3-27.4 years). There were no significant differences in ODI (20.3 vs 22.6 for the bilateral and unilateral approaches, respectively), RMDQ (3.99 vs 4.8, respectively), or pain scores between treatment groups. Back symptoms were reduced in 74.8% (bilateral: 74.6% vs unilateral: 75%; not significant), and leg symptoms in 80.6% of the patients (bilateral: 73.1% vs unilateral: 85.4%; p = 0.048). In total, 72.1% (bilateral) and 80.0% (unilateral) of patients reported good overall treatment results (p = 0.226). Significantly more patients in the unilateral group reported a better overall satisfaction with the procedure (82.1% vs 69.1%; p = 0.047). CONCLUSIONS: There were no differences in postoperative functional disability and pain between the surgical techniques. The significant differences in patient satisfaction and reduction in leg symptoms were unrelated to surgical technique. The overall treatment results were satisfactory. Both techniques are safe and effective options for treating patients with single-level DLSS.