bluuebunny/crossref_metadata_2025_split huggingface dataset:
ACDF Graft Selection by Surgeons: Survey of AOSpine Members
Authors: Yoon S. Tim , Konopka Jeff , Brodke Darrel S. , Youssef Jim , Wang Jeffrey , Park Jong-Beom , Meisel Hans Jörg 
Published: May 2015

Introduction The choice of graft material for anterior cervical disc fusion (ACDF) surgery is presumed to be very important in achieving fusion. Worldwide, a large diversity of graft options exists but no published data exist on actual use. Our objective is to determine the most commonly used graft materials in ACDF, whether the choice is affected by surgeon's training, years in practice, geographical location of practice setting, or surgeon's perceived difficulty in achieving fusion for a particular case. We also want to confirm our previous assumption that surgeons feel that the choice of graft material is important for outcome and that there is sufficiently good comparative and safety data on the most common grafts. Materials and Methods A 23-question survey was sent out to 5,334 surgeons using the Global AOSpine database. Response data were then stratified into surgeon training, years of practice, practice type, and global region. To further characterize type of ACDF graft, we classified common graft materials into structural and nonstructural components. Results Nearly all surgeons, 94.6%, performing ACDF believe that cervical disc fusion is important for a successful patient outcome. Overall, 89.3% of the surgeons believe that graft impacts fusion rates and 86.0% affect time to fusion. The use of a cage is currently the most common structural graft component used worldwide at 64.1%. Of the surgeons who use cages, the PEEK cage makes up for 84% of them. North American surgeons have stopped this trend and use composite allograft more commonly. Surgeon experience seems to be positively related to the use of a cage because surgeons with a greater number of years of practice are more likely to select a cage. The choice to add a nonstructural graft component was reported at 74%. This result was similar for performing multilevel fusions at 72.8%. The most common nonstructural graft material depends on the type of surgery, simple or complex. For simple cases, local autograft is most common and for multilevel fusions, allograft iliac cancellous is most widely used. Most surgeons are not satisfied with the available literature comparing the effectiveness of grafts, but believed there was sufficient evidence to support the use of their chosen graft. Conclusion Almost all surgeons believe that fusion is important to ACDF surgery outcomes and that most surgeons believe choice of graft impacts fusion. However, this survey indicates that there is great variability in the type of graft material used by spine surgeons across the world and surgeons feel that there is insufficient comparative data to help choose between graft types. This variability in surgeon practice and gap in the literature indicate an important opportunity to change surgeon practice with well-conducted comparative studies.
Multilevel Anterior Cervical Discectomies and Cage-Augmented Fusion without Plate Fixation
Authors: Maati Hossam 
Published: May 2015

Objective The number of surgical techniques of decompression and solid interbody fusion as a treatment for cervical degenerative disc disease (DDD) has increased rapidly. Cage-assisted anterior cervical discectomy and fusion (ACDF) has proven to be a safe and effective procedure for one and two-level DDD. Multilevel cervical discectomy usually requires plate and screw fixation for maintaining the spinal curvature and increasing the graft fusion rate. Clinical results after three or four-level interbody cage-augmented ACDF have been reported in very few literatures. We investigated the safety and effectiveness of cages used in such procedures without plate fixation and evaluated the results. Methods Forty-five patients suffering from three or four-level cervical DDD underwent cage (PEEK or titanium)-assisted ACDF without plate fixation. The cervical DDD was confirmed by radiography and magnetic resonance imaging. The patients underwent radiographic evaluation to assess cervical lordosis, segmental height of cervical spine, foraminal height, cross-sectional area of foramina, the angle between the two adjacent endplates, and spinal stability. Neurological outcomes were assessed using the Prolo scale. Neck pain was assessed using the visual analogue scale (VAS). The follow-up period ranged from 27 to 53 months (mean, 35 months). Results A significant improvement ( p < 0.001) in the Prolo scale scores (preoperatively 7.9 ± 1.7 and postoperatively 8.7 ± 1.1) and VAS pain scores (preoperatively 8.8 ± 1 and postoperatively 3 ± 1.5) was demonstrated. A significant increase in cervical lordosis, segmental height, foraminal height, cross-sectional area of foramina, and angle between the two adjacent endplates was noted. Good stability was obtained in all patients 12 months postoperatively and the complication rate was 0%. Conclusion Multilevel (3 or 4) anterior cervical discectomies and cage (PEEK or titanium)-augmented interbody fusion without plating is a good method for management of multilevel cervical DDD. It provides long-term stabilization, increases lordosis, segmental and foraminal height, and cross-sectional area of foramina. Satisfactory neurological outcomes can be obtained and donor site complication can be avoided.
Morphometric Study of the Hypoglossal Nerve and the Hypoglossal Canal for the Surgery of the Upper Cervical Spine
Authors: Hong Jae Taek , Kim Il Sup , Kim Joon Yeong , Kim Moon Seok 
Published: May 2015

Objective The upper cervical pathology is not an uncommon disease in the congenital anomaly, elderly population, and patients with rheumatoid. Newly developed operative techniques in high cervical region could be related to neurovascular injury. The objective of this study was to determine the anatomic relationship of the hypoglossal nerve (HN), internal carotid artery (ICA), bony structures, and hypoglossal canal and demonstrate the vulnerability of the neurovascular structures. Methods Eleven fresh cadavers (5 male and 6 female) were dissected bilaterally to expose neurovascular structures of the high anterior cervical region and hypoglossal canal. The anatomical relationship was evaluated between C1 bony structures (midline, lateral mass, and C1 transverse process) and the ICA and HN. The angle of the hypoglossal canal was also evaluated. Results The HN consistently traveled toward the midline at C2–3 and was safe caudal to C3–4. The HN is usually located lateral to the ICA. Relative anatomical relationship between the HN and surrounding bony structures at the level of C1 are as given below. The mean diameter of the HN was 2.4 mm (2–3.5 mm). The mean distance between the midline and the HN was 30.15 mm (24–35 mm). The mean distance between the margin of the C1 lateral mass (LM) and the HN was 4 mm (−3–11 mm). The mean distance between the C1 transverse process and the HN was 9.3 mm (3–16 mm). The transverse angle of the hypoglossal canal was between 31.6 and 55.5 degrees. The mean distance between the midline and the ICA was 26.06 mm (18–32 mm). In the cases of the medially displaced ICA, the HN is located more on the medial side relative to the LM. There was no reversed anatomical location of the HN and the ICA in the studied specimen. Conclusion On the basis of this study, spine surgeons can have enhanced knowledge of upper cervical anatomy. Although it has been rarely reported in the literature, the hypoglossal nerve and the ICA may be damaged during upper cervical spine surgery, especially in the cases with the ICA displaced medially.
Anterior Cervical Discectomy and Fusion: Comparison between Zero-Profile Implants and Anterior Cervical Plate and Spacer
Authors: Alimi Marjan , Njoku Innocent , Hofstetter Christoph P. , Kesavabhotla Kartik , Tsiouris Apostolos J. , Boockvar John , Härtl Roger 
Published: May 2015

Introduction Interposition grafts combined with anterior plating currently remain the gold standard for anterior cervical discectomy and fusion. The use of anterior plates increases fusion rates, but may be associated with higher rates of postoperative dysphagia. The current study aimed to compare the clinical and radiological outcomes following anterior cervical discectomy and fusion (ACDF) using zero-profile anchored spacers versus standard interposition grafts with anterior plating. Materials and Methods This was a retrospective case series. A total of 53 male and 51 female consecutive patients (164 total operated levels) who underwent ACDF between 2007 and 2011 were included. The mean clinical follow-up was 15.7 ± 1.2 months (SEM) for patient with zero-profile implants and 14.8 ± 2.1 months for patients with conventional ACDF with anterior plating. Patient demographics, operative details, clinical outcomes, complications, and radiographic imaging were reviewed. Dysphagia was determined using Bazaz criteria. Results Clinical outcome scores were similar between the two groups as measured by the modified JOA and Nurick scores. Zero-profile constructs gave rise to significantly less prevertebral soft-tissue swelling compared with constructs with anterior plates postoperatively (15.74 ± 0.52 vs. 20.48 ± 0.85 mm, p < 0.001, respectively) and at the latest follow-up (10.88 ± 0.39 vs. 13.72 ± 0.67 mm, p < 0.001, respectively). At latest follow-up, there was a significantly lower incidence of dysphagia associated with utilization of zero-profile constructs as compared with anterior plate (1.5 vs. 20%, p = 0.001, respectively). Conclusion Zero-profile implants lead to functional outcomes similar to standard anterior plate constructs. Avoiding the use of anterior locking plate may decrease the risk of postoperative dysphagia.
Intraoperative Cone Beam CT (O-Arm) and Stereotactic Navigation (StealthStation) System in Complex Adult Spine Surgery: Early Experience and Learning Curve
Authors: Contreras Ana , Batke Juliet , Dea Nicolas , Dvorak Marcel , Fisher Charles , Street John 
Published: May 2015

Introduction Computer-assisted navigation and intraoperative imaging systems have been shown to improve pedicle screw accuracy in a variety of instrumented spine surgeries. There is limited data evaluating the clinical learning curve for surgeons and its relationship to patient outcomes when using intraoperative navigation and imaging systems. We examined the clinical learning curve and patient outcomes of using O-Arm and StealthStation for six fellowship-trained spine surgeons at our institution, a single quaternary referral center, from 2009 to 2013. Materials and Methods This ambispective study examined 231 surgical cases where O-arm and StealthStation were used to facilitate pedicle instrumentation. The learning curve was determined by examining the year-by-year total operative time and blood loss, operative time and blood loss per surgical level, and the incidence of surgery-related adverse events. Adverse events were prospectively collected using the spine adverse events severity system (SAVES). Results O-arm and StealthStation were acquired at our institution in late 2008 and all spine surgeons were using this navigation system by the beginning of 2009. A total of 231 patients had screws placed using the O-arm and StealthStation between January 1, 2009 and December 31, 2012. There were 430 screws placed in 27 cases in 2009, 556 screws in 54 cases in 2010, 674 screws in 59 cases in 2011, and 758 screws in 75 cases in 2012, p < 0.05. The average estimated blood loss (EBL) decreased from 1,229 mL in 2009 to 907 mL in 2012, p < 0.05. The EBL per case per number of levels instrumented decreased from 5.72 mL in 2008 to 2.39 mL in 2012, p < 0.05. Mean operating time decreased from 407 minutes to 378 minutes from 2009 to 2012, p < 0.05. The number of misplaced screws per case decreased from 0.78 to 0.54 from 2009 to 2012, p < 0.05. There were no significant differences in incidences of dural tear, surgical site infection, or other surgical adverse events during the study period. Conclusion Our results demonstrate that there is a learning curve to the use of intraoperative CT-based navigation, as measured by OR time, intraoperative blood loss, and screw malposition. There were no significant differences in surgical adverse events during this learning period.
A Comparison between Anterior and Posterior Surgical Approaches in the Treatment of Cervical Spondylotic Myelopathy
Authors: Tan Gamaliel , Fehlings Michael , Koh Deanna 
Published: May 2015

Introduction Cervical spondylotic myelopathy (CSM) is a common problem in our aging population. We aim to compare the efficacy and safety of anterior and posterior approaches in the surgical treatment of CSM using validated outcome measures in a prospective cohort study. Materials and Methods Patients with defined clinical features of CSM were recruited from three hospitals in Singapore between October 2009 and December 2010. A total of 17 participants were recruited, and baseline demographic variables and outcome measure scores were established. Namely, the modified Japanese Orthopaedic Association (mJOA) score, Nurick, Short Form-36 (SF-36) Health Survey Questionnaire score, and Neck Disability Index (NDI). Participants underwent decompressive surgery by anterior or posterior approach, with choice of technique left to surgeon preference. Scores were retaken at 6, 12, and 24 months after surgery for comparison against baseline, within and between groups through the follow-up period. Results Patients who underwent anterior approach surgery were younger, had fewer comorbidities, less extensive disease, better SF-36 physical functioning, and mJOA scores at baseline. Both groups had clinically significant improvement in scores based on validated minimum clinically important difference (MCID) values at the end of the 2-year follow-up period. Score improvement was more sustained in the anterior group, whereas in the posterior group improvement in scores was greatest at 6 months post-decompression, but declined thereafter (albeit to values still three times that at baseline). A patient who underwent posterior approach surgery developed anemia secondary to perioperative blood loss. There were no cases of implant-related complications or cases of revision surgery. Conclusion This study highlights the differences in patient and disease factors influencing choice of surgical approach and shows the safety and efficacy of CSM surgery regardless of approach.
Subaxial Cervical Sagittal Alignment following C1–C2 Fusion for Atlanto–Axial Osteoarthritis
Authors: Kang Daniel , Lehman Ronald , Wagner Scott , Riew K. Daniel 
Published: May 2015

Introduction Few studies have evaluated the outcomes following C1–C2 fusion for atlanto–axial osteoarthritis (AAOA). Previous studies in rheumatoid arthritis (RA) patients with atlanto–axial instability have demonstrated unexpected development of subaxial kyphosis following C1–C2 fusion; however, this complication in patients with AAOA remains unknown. Therefore, we set out to evaluate the subaxial cervical sagittal alignment following C1–C2 fusion for AAOA. Methods We performed a retrospective review of all patients following C1–C2 fusion from a single center, single-surgeon from 2002 to 2012. All charts, records, and imaging studies were reviewed for each case, and preoperative, immediate postoperative, and final follow-up plain films were evaluated. Patients were divided into three diagnosis categories for further comparison: AAOA, rheumatoid, and trauma. Results A total of 29 patients were included in the review, with an average radiographic follow-up of 38 months. There were 14 patients with AAOA, 4 patients with RA/gout (1 gout patient with C1–C2 pannus causing spinal cord compression), and 11 patients treated for a traumatic etiology. Overall, we found that patients with AAOA did not have a significant change in subaxial sagittal alignment from preoperative to final follow-up (−11.7 to −13.8 degrees, p = 0.23, [− degrees] = lordosis, [+ degrees] = kyphosis), which was similar in the trauma group (−9.7 to −8.4 degrees, p = 0.47). This was comparable to the RA/gout group that demonstrated a significant change in sagittal alignment from −20.5 to −0.2 degrees ( p = 0.04). Conclusion Our study demonstrates that patients with nonrheumatologic conditions (AAOA and trauma) undergoing C1–C2 fusion do not develop postoperative subaxial cervical kyphosis. We postulate that the loss of subaxial lordosis in the rheumatologic patients may be a function of their underlying systemic disease.
Biomechanical Evaluation of a New Posterior Stabilization Device
Authors: Hartensuer Rene , Riesenbeck Oliver , Schulze Martin , Gehweiler Dominic , Raschke Michael J. , Pavlov Paul W. , Vordemvenne Thomas 
Published: May 2015

Introduction Over the last two decades, different techniques to stabilize the spine have been developed. The gold standard in spinal stabilization today is the pedicle screw. However, different techniques like different types of facet fixation devices are available. Based on different principles of facet fixation, a new implant is available, the so called “Facet Wedge.” The purpose of this study is to evaluate the primary stability of this new approach for facet fixation in comparison with established posterior fixation techniques such as pedicle screws and translaminar screws with and without anterior cage interposition. Materials and Methods In a two-arm biomechanical study using a robot-based spine tester, 24 monosegmental fresh frozen nonosteoporotic human motion segments (L2–L3 and L4–L5) were tested. Facet Wedge stand-alone and in combination with an anterior fusion cage was compared with pedicle screws and translaminar screws. Results All tested techniques could stabilize an intact motion segment effectively. In the used setup, Facet Wedge was comparable to pedicle screws for lateral bending, extension, and flexion and slightly superior for axial rotation. Facet Wedge showed a superior kinematic capacity compared with translaminar screws. Conclusion Facet Wedge offers a novel posterior approach in achieving primary stability in lumbar spinal fixation. In the used model, Facet Wedge has a comparable primary stability to pedicle screws and potential advantages over translaminar screws.
Evaluation of Cartilaginous End Plate and Annulus Fibrosus in Lumbar Disc Degeneration using OFF Resonant Saturation Ratios Assessed by a 3D Ultra Short Echo Time Sequence at 3 Tesla
Authors: Gebhard Harry , Martirosian Petros , Springer Fabian , Grosse Ulrich , Schick Fritz , Nikolaou Konstantin , Syha Roland 
Published: May 2015

Introduction Ultrashort echo time (UTE) imaging in combination with off-resonant saturation ratios (OSR) is increasingly used for characterization of tissue with fast signal decay, such as the annulus fibrosus (AF) as well as the upper and lower cartilaginous end plate (EP). The aim of this study was to assess effects of age, gender, and location of OSR measurement on evaluation of lumbar disc degeneration. Materials and Methods A total of 35 lumbar intervertebral discs of 12 fresh-frozen cadaveric specimens (median age 66 years, range 49–75 years) were examined in a whole-body MR scanner using a sagittal 3D UTE sequence with an isotropic submillimeter resolution of 0.7 mm (TE 0.07 milliseconds, TR 10.3 milliseconds, FoV 128 mm, and FA 10 degrees) with and without off-resonant saturation preparation pulse at 3 T. The off-resonance frequency varied between 1 and 5 kHz. OSRs of images with and without preparation pulse were calculated for upper and lower EP as well as for AF. Intervertebral discs were classified healthy (CO, n = 20), mild degeneration (MIL, n = 7), and severe degeneration (SEV, n = 8) concerning morphology and signal alteration in conventional MR sequences and UTE imaging. A nonparametric U-test reports level of significance. Correlation between age and OSRs is calculated using Spearman rank correlation coefficient. Effects of different off-resonance frequencies and measurement locations on lumbar disc degeneration are investigated using logistic regression and ROC analysis. Cut-off values, sensitivity, and specificity are given. Results Best differentiation between mild and severe degeneration was seen at an off-resonance frequency of 1 kHz for AF (sensitivity 87.5%/specificity 87.5%/cut-off 0.34) and the lower EP at 1.5 kHz (sensitivity 100%/specificity 85.7%/cut-off 0.29). Comparison of CO and MIL groups revealed best differentiation at 1 kHz for upper EP (sensitivity 100%/specificity 80%/cut-off 0.35). A reasonable correlation between age and OSRs in healthy lumbar discs was seen in AF for all investigated frequencies, ρ = 0.49 (5 kHz) to 0.61 (2 kHz), and in lower EP for frequencies above 2 kHz, ρ = 0.51 (3 kHz) to 0.71 (5 kHz). Significant differences between OSR measurements were seen in AF of healthy female and male lumbar discs for all investigated sequences and in upper EP at 1 kHz. Conclusion OSR assessment might be a suitable method for detection of early stage lumbar disc degeneration and should be preferably performed using off-resonance frequencies between 1 and 2 kHz. Age might influence OSR measurement in AF and lower EP. Gender seems to influence results of OSRs, especially in evaluation of AF. [Figure: see text]
Minimally Invasive Transforaminal Lumbar Interbody Fusion: Meta-Analyses of the Fusion Rates. What is the Optimal Graft Material?
Authors: Parajón Avelino , Alimi Marjan , Christos Paul , Torres-Campa Jose M. , Navarro Rodrigo , Moriguchi Yu , Härtl Roger 
Published: May 2015

Introduction It had been previously shown that minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) has similar fusion rates and complication rates compared with open TLIF surgery. Different graft materials are being used for fusion. However, no previous studies have compared the fusion rates of different graft materials. The aim of this study was to compare the fusion rates of different graft materials used in MIS TLIF, via meta-analysis of the published literature. Materials and Methods A MEDLINE search was performed to identify the studies reporting fusion rates of MIS TLIF using different graft materials. A database was created which included patient demographics, preoperative data, type of graft material, clinical outcome, fusion rate, and duration of follow-up. Groups were defined based on the type of graft used. Meta-analysis of the fusion rate was performed using the StatsDirect statistical software. Results Forty series with a total of 1,320 patients were included. Age and gender distribution were homogeneous in almost all series. The most frequently operated level was L4/L5. Implanted cages were made of PEEK, titanium, or Hydrosorb. Significant clinical improvement was observed in all studies. Fusion rates were high, regardless of the type of the graft, ranging from 92 to 99% with different graft materials. Comparison of all rhBMP series with all non-rhBMP series showed fusion rates of 96.6 versus 92.5%, respectively. Iliac bone graft alone compared with non-Iliac bone graft showed fusion rates of 92.8 and 92.4%, respectively. The lowest fusion rate was observed with an isolated use of autologous local bone (91.7%). However, the addition of rhBMP to local bone increased the fusion rate up to 95% and the addition of non-rhBMP grafts to the local bone increased it up to 93%. The median complication rate was 8.82%, varying between 0 and 35.71%. Conclusion Utilization of rhBMP for MIS TLIF resulted in high fusion rates. Isolated use of local bone resulted in the lowest fusion rate. Addition of non-rhBMP grafts to local bone increased the fusion rate moderately, and addition of rhBMP was associated with a higher increase. Given the potential complications of iliac bone harvesting and rhBMP, the decision on the type of graft material should be made separately for each patient, based on specific characteristics. When rhBMP is used, efforts should be made to use the lowest possible amount.