bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Hydroxyapatite Stick on Pedicle Screw Fixation in Degenerative Lumbar Spine
Authors: Shin Sung Joon , Lee Ji-Ho , Lee Jae Hyup 
Published: March 2018

Study Design:
A prospective, within-patient, left-right comparative study.

Objective:
To evaluate the efficacy of hydroxyapatite (HA) stick augmentation method by comparing the insertional torque of the pedicle screw in osteoporotic and nonosteoporotic patients.

Summary of Background Data:
Unsatisfactory clinical outcomes after spine surgery in osteoporotic patients are related to pedicle screw loosening or pull-outs. HA, as a bone graft extender, has a possibility to enhance the fixation strength at the bone-screw interface.

Methods:
From November 2009 to December 2010, among patients who required bilateral pedicle screw fixation for lumbar spine surgery, 22 patients were enrolled, who recieved unilateral HA stick augmentation and completed intraoperative insertional torque measurement of each pedicle screws. On the basis of preoperative evaluation of bone mineral density, patients with osteoporosis had 2 HA sticks inserted unilaterally, and 1 stick for patients without osteoporosis. Pedicle screw loosening and pull-outs were assessed using 12-month postoperative CT scans and follow-up radiographs. Clinical evaluation was done preoperatively and at 1 year postoperatively, based on Visual Analog Scale score, Oswestry Disability Index, and Short Form-36 Health Survey.

Results:
Regardless of bone mineral density, the average torque value of all pedicle screws with HA stick insertion (HA stick inserted group) was significantly higher than that of all pedicle screws without HA insertion (control group) (P<0.0001). Same results were seen in the HA stick inserted subgroups and the control subgroups within both of the osteoporosis group (P=0.009) and the nonosteoporosis group (P=0.0004). There was no statistically significant difference of the rate of pedicle screw loosening in between the HA stick inserted group and the control group. Clinical evaluation also showed no statistically significant difference in between patients with loosening and those without.

Conclusions:
The enhancement of initial pedicle screw fixation strength in osteoporotic patients can be achieved by HA stick augmentation.
The Ideal Cage Position for Achieving Both Indirect Neural Decompression and Segmental Angle Restoration in Lateral Lumbar Interbody Fusion (LLIF)
Authors: Park Se-Jun , Lee Chong-Suh , Chung Sung-Soo , Kang Sang-Soo , Park Hyun-Jin , Kim Se-Hun 
Published: March 2018

Study Design:
A prospective radiographic analysis.

Objective:
To assess the ideal cage position for lateral lumbar interbody fusion (LLIF) together.

Summary of Background Data:
Achieving both indirect decompression and restoration of the segmental angle (SA) appear to be contrary to one another because the anteriorly located cage might be advantageous for restoring the SA, and posteriorly located cage might be favorable for achieving the indirect decompression effect. Little has been known about the significance of cage position in LLIF.

Methods:
Forty-one patients who underwent LLIF followed by percutaneous pedicle screw fixation for 94 levels were evaluated. Postoperative plain radiographs and magnetic resonance images were obtained 3 days after surgery. The cage position was determined by the anterior, middle, and posterior portions. The anterior and posterior disk heights, SA, cross-sectional area of the thecal sac (CSA), and the foraminal area (FA) were compared according to the cage position.

Results:
The cage was placed in the anterior area for 31 levels and middle for 63 levels. The cage height was 13.0±1.3 degrees. The increases in anterior disk height and SA were significantly greater in the anterior group (9.1 mm, 6.1 degrees) than those of the middle group (6.7 mm, 2.4 degrees). Posterior disk height increased by a mean of 4.5 mm, but its change did not differ according to the cage position. CSA and FA increased by 36.5% and 69.6%, respectively. There were no significant differences in the CSA and FA increases with respect to the cage position. Regression analysis showed that the increase of SA was affected by cage position, but the increase ratios of CSA and FA were not affected.

Conclusions:
The cage position within the anterior 1/3 of disk space is better for achieving the restoration of the SA without compromising the indirect neural decompression, if the height of cage is large enough.
Clinical and Radiographic Outcomes in Patients Undergoing Single-level Anterior Cervical Arthrodesis
Authors: Burkus John K. , Dryer Randall F. , Arnold Paul M. , Foley Kevin T. 
Published: March 2018

Study Design:
A prospective study with historical controls.

Objectives:
To evaluate and compare the safety and effectiveness of recombinant human bone morphogenetic protein-2 (rhBMP-2) with allograft for anterior cervical discectomy and fusion (ACDF) in patients with symptomatic single-level cervical degenerative disk disease.

Summary of Background Data:
rhBMP-2 is an osteoinductive protein that has been shown to induce fusion when used as an implant with a suitable carrier in spine surgery. However, some previous studies have shown rhBMP-2 use to be associated with a higher complication rate.

Methods:
Investigational patients (224) with single-level cervical degenerative disk disease underwent ACDF with rhBMP-2 at a dose of 0.6 or 1.05 mg and were compared with historical control patients (486) treated with allograft spacer and cervical plate.

Results:
At 24 months, improvement was significantly greater in the investigational group (37.1 points) than in the control group for Neck Disability Index (P=0.002) and arm pain (P=0.031). The overall neurological success rate was higher in the investigational group (P<0.001). Neck pain and general health status (SF-36 PCS and MCS) were similar. Fusion rate in the investigational group was higher than in the control group (99.4% vs. 87.2%, P=0.002).
Cumulative adverse event rates at 24 months were similar; however, higher rates of dysphagia (P=0.001), local swelling (P=0.024), oropharyngeal pain (P=0.013), neck pain (P=0.019), and foraminal stenosis (P=0.002) were observed in the investigational group. Heterotopic ossification was also higher in the investigational group.

Conclusions:
At doses of 0.6 or 1.05 mg in a PEEK interbody cage, rhBMP-2 was effective in inducing fusion and improving Neck Disability Index and arm pain in single-level ACDF patients; however, higher rates of certain adverse events were observed in the investigational group.

Level of Evidence:
Level 2.
Lumbar Discectomy
Authors: Koen Errikos A. , Antonarakos Petros D. , Katranitsa Labrini T. , Poulis Kostas E. , Apostolou Thomas M. , Christodoulou Evangelos A. , Christodoulou Anastasios G. 
Published: March 2018

Study Design:
We followed a longitudinal observational design with 2 assessment points, presurgery and postsurgery, in 83 consecutive patients undergoing single-level lumbar discectomy.

Objective:
Prognostic data can be gathered from commonly used generic outcome measures to identify patients at risk of persistent leg pain–associated chronicity, following lumbar discectomy

Summary of Background Data:
Suboptimal results observed, following open lumbar discectomy, have been connected to the interplay among presurgery pain characteristics, functional and psychosocial adaptations like persistent pain, disability, and depression. Outcome predictive qualities have been recently attributed to well-known outcome measures. However, most studies on prognostic indicators use multiple tools designs, inhibiting clinical application. Here we elaborate on predictive indications identified in 2 generic patient-rated questionnaires, Short Form-36 (SF-36) and McGill Pain, as many of their domains can evaluate factors related to unfavorable outcomes.

Methods:
For the prognostic value calculations, multivariate logistic [Short-Form McGill Pain Questionnaire (SF-MPQ)] and linear regression models (SF-36) were fitted to investigate the association between presurgery and postsurgery scores. In all models, the presurgical score at question was assigned as the dependent variable while age, sex and presurgery score at question were the independent variables.

Results:
Overall, a statistically significant amelioration in both SF-MPQ and SF-36 scores was observed postsurgically. For the SF-MPQ leg cramping, gnawing, burning, and aching pain symptoms, when present presurgically, were the least responsive to treatment. For the SF-36, mental scores overall were less responsive than physical equivalents postoperatively, while general health perception improved only marginally. Differences in pain level scores did not correlate with an equivalent reduction in postsurgery anxiety and depression indices.

Conclusions:
SF-MPQ and SF-36 can assist in treatment decision, as they can readily identify patients at risk of unfavorable outcomes even in primary/clinical settings. The above findings additionally suggest a wider scope of clinical use for the above questionnaires allowing parallel processing and interpretation of the same patient data.

Levels of Evidence:
Level I.
Interobserver and Intraobserver Reliability in the Radiologic Assessment of Lumbar Interbody Fusion
Authors: Kroeze Robert J. , Graat Harm C.A. , Pluymakers Winand J. , Marting Louis N. , van Dijk Martijn , van Dijke Cees F. , vd Klis Anton H. , Verberne Steven J. , de Gruyter Albert J. , Temmerman Olivier P.P. 
Published: March 2018

Study Design:
Retrospective cohort study comparing intraobserver and interobserver reliability of 3 different radiologic fusion classifications following uninstrumented single-level anterior lumbar interbody fusion.

Objective of the Study:
The objective of the study was to compare the intraobserver and interobserver reliability of 3 different radiologic spinal fusion scoring systems.

Summary of Background Data:
Knowledge regarding radiologic spinal fusion is crucial when studying patients that were treated with lumbar interbody fusion. The scoring system should be reliable and reproducible. Various radiologic classification systems coexist, but the reliability of these systems has thus far not been compared in a single consecutive group of patients. The aim of the present study was the identification of the most valid scoring system in the assessment of interbody fusion.

Methods:
We studied a retrospective consecutive cohort of 50 patients who underwent an anterior lumbar interbody fusion procedure by a single surgeon using a stand-alone cage performed between 1993 and 2002. Plain anterior-posterior, lateral radiographs, and flexion-extension radiographs were made during follow-up visits and were used for analysis. The interbody fusion was scored on these radiographic images using the 3 classification systems (Brantigan, Burkus, and the Radiographic Score) by 2 experienced musculoskeletal radiologists and 2 senior orthopedic spinal surgeons all of whom were blinded to clinical data and outcome.

Results:
Of the 3 classifications included in the current study, the Burkus classification had a moderate interobserver agreement and a substantial to perfect intraobserver agreement. The other classifications (Bratingan and the Radiographic Score) showed only fair interobserver agreement and moderate to substantial agreement among all observers. No significant differences in reliability between orthopedic surgeons and radiologists were found for all 3 classifications.

Conclusions:
The Burkus classification system was classified as most reliable in this, but showed only moderate interobserver agreement. Therefore, the need for a more reliable classification system for the radiographic assessment of lumbar interbody fusion still exists to date.
Cross-Sectional Area of the Lumbar Spine Trunk Muscle and Posterior Lumbar Interbody Fusion Rate
Authors: Choi Man Kyu , Kim Sung Bum , Park Chang Kyu , Malla Hridayesh P. , Kim Sung Min 
Published: March 2018

Study Design:
A retrospective study.

Objective:
To investigate the relationship between trunk muscle cross-sectional area (MCSA) and fusion rate after posterior lumbar interbody fusion using pedicle screw fixation (PLIF-PSF).

Summary of Background Data:
Although trunk muscles of the lumbar spine contribute to spinal stability and alignment, effect of trunk muscles on spinal fusion rate and time to fusion is unclear.

Methods:
A total of 192 adult patients with degenerative lumbar disease who underwent PLIF-PSF at L3–L4 or L4–L5 were included. The MCSA of the flexor (psoas major, PS), extensor (erector spinae, ES; multifidus, MF) were measured using preoperative lumbar magnetic resonance imaging at 3 segments. Bone union was evaluated using lumbar dynamic plain radiography. Patients were divided into 2 groups according to the presence of bone fusion.

Results:
Most PS MCSAs in the fusion group were significantly larger than in the nonfusion group, except for MCSA at the L2–L3 segment (all P<0.05). In cases of ES and MF MCSAs, 4 of 6 segments were significantly large. Multivariate analysis revealed that the PS MCSA at L4–L5 was an independent factor for decreased possibility of nonfusion status in both segments (OR=0.812, P=0.028). Pearson analysis demonstrated that the most trunk MCSAs were negatively correlated with time to fusion for both segments and PS MCSAs exhibited a significant correlation with time to fusion except for MCSA at the L2–L3 segment.

Conclusions:
Trunk MCSAs were significantly larger for a fusion group than a nonfusion group. As trunk MCSAs increased, fusion timing decreased.
Complications, Readmissions, and Revisions for Spine Procedures Performed by Orthopedic Surgeons Versus Neurosurgeons
Authors: Mabud Tarub , Norden Justin , Veeravagu Anand , Swinney Christian , Cole Tyler , McCutcheon Brandon A. , Ratliff John 
Published: March 2018

Study Design:
Retrospective database analysis.

Objective:
To examine the impact of training pathway, either neurosurgical or orthopedic, on complications, readmissions, and revisions in spine surgery.

Summary of Background Data:
Training pathway has been shown to have an impact on outcomes in various surgical subspecialties. Although training pathway has not been shown to have a significant impact on spine surgery outcomes in the perioperative period, long-term results are unknown.

Materials and Methods:
A retrospective analysis of 197,682 patients receiving 1 of 3 common spine surgeries [lumbar laminectomy, lumbar fusion, and anterior cervical discectomy and fusion (ACDF)] between 2006 and 2010 was conducted. Patient data were obtained from a large claims database. Postoperative adverse effects, all-cause readmission, revision surgery rates, and intermediary payments in these cohorts of patients were compared between spine surgeons with either neurosurgical or orthopedic backgrounds.

Results:
Patient demographics, hospital-stay characteristics, and medical comorbidities were similar between neurosurgeons and orthopedic surgeons. The risks of surgical complications, all-cause readmission, and revision surgery were also similar between neurosurgeons and orthopedic surgeons across all procedure types assessed, with several minor exceptions: neurosurgeons had marginally higher odds of any complication for lumbar fusions [odds ratio (OR) 1.14; 95% confidence interval (CI), 1.09–1.20] and ACDFs (OR, 1.09; 95% CI, 1.04–1.15). Neurosurgeons also had slightly higher rates of revision surgery for concurrent lumbar laminectomy with fusion (OR, 1.14; 95% CI, 1.08–1.22), and ACDFs (OR, 1.20; 95% CI, 1.14–1.28). No associations between surgeon type and any particular complication were consistently observed for all procedure groups. There were also no associations between surgeon type and 30-day all-cause readmission. Median total intermediary payments were somewhat higher for neurosurgery patients for all procedure groups assessed.

Conclusions:
Few significant associations between surgeon type and patient outcomes exist in the context of spine surgery. Those which do are small and unlikely to be clinically meaningful.

Level of Evidence:
Level 3.
Graft Subsidence and Revision Rates Following Anterior Cervical Corpectomy
Authors: Weber Michael H. , Fortin Maryse , Shen Jian , Tay Bobby , Hu Serena S. , Berven Sigurd , Burch Shane , Chou Dean , Ames Christopher , Deviren Vedat 
Published: March 2018

Study Design:
Retrospective cohort study.

Objective:
To assess the subsidence and revision rates associated with different interbody cages following anterior cervical corpectomy and reconstruction.

Summary of Background Data:
Different interbody cages are currently used for surgical reconstruction of the anterior and middle columns of the spine following anterior cervical corpectomy. However, subsidence and delayed union/nonunion associated with allograft and cage reconstruction are common complications, which may require revision with instrumentation.

Materials and Methods:
We reviewed the cases of 75 patients who underwent cervical corpectomy and compared the radiographic graft subsidence and revision rates for fibula allograft, titanium mesh cage, titanium expandable cage, and carbon fiber cages. Subsidence was calculated by comparing the immediate postoperative lateral x-ray films to those obtained during follow-up visits.

Results:
The average graft subsidence was 3 mm and revision rate was 25% for fibula allograft versus 2.9 mm and 11.1%, 2.9 mm and 18.8% for titanium mesh cages and titanium expandable cages, respectively. The average graft subsidence for carbon fiber cages was 0.7 mm with no revision surgery in this subset.

Conclusions:
Our findings suggest that subsidence and revision rates following anterior corpectomy and interbody fusion could be minimized with the use of a carbon fiber cage.
Dynamic Evaluation of the Cervical Spine and the Spinal Cord of Symptomatic Patients Using a Kinetic Magnetic Resonance Imaging Technique
Authors: Xiong Chengjie , Daubs Michael D. , Scott Trevor P. , Phan Kevin H. , Suzuki Akinobu , Ruangchainikom Monchai , Roe Allison K. , Aghdasi Bayan , Tan Yanlin , Wang Jeffrey C. 
Published: March 2018

Purpose:
The purpose of this study was to examine the movement of the spinal cord and its relationship to the spinal canal in patients with mild spondylosis using kinetic magnetic resonance imaging (kMRI).

Methods:
Weight-bearing, multiposition kMRI was performed on symptomatic patients through a full range of flexion-extension. A total of 52 study patients were selected based on the C2–C7 Cobb angle of sagittal alignment: lordotic (from 30 to 45 degrees). We evaluated dynamic changes in different parameters from flexion-extension: spinal canal diameter (CD), spinal cord diameter (SCD), space available for the cord, anterior space available for the cord (ASAC), posterior space available for the cord (PSAC), average distance between the anterior canal and the cord (d-value), and global angle for the spinal canal and cord.

Results:
The CD tended to decrease from flexion to extension from C3/C4 to C6/C7, however, there were no significant differences at the proximal and distal levels, C2/C3 and C7/T1. There were no significant differences of SCD between different postures. The SCD tended to decrease from C2/C3 to C7/T1. The ASAC followed the same pattern as CD-values. The ASAC was narrowest at C4/C5 and C5/C6. The PSAC tended to increase from C2/C3 to C7/T1. The spinal cord shifted anteriorly with extension and posteriorly with flexion. In addition, the spinal cord maintained its curve with the movement.

Conclusions:
The kinematics of spinal cord motion may be associated with the pathogenesis of cervical spondylotic myelopathy. However, the spinal cord maintains its curve with position changes. Consequently, different motions of the cervical spine may affect spinal cord migration and cause changes in ASAC and PSAC.
Insertional Torque in Cervical Vertebrae Lateral Mass Screw Fixation
Authors: Shinohara Akira , Sairyo Koichi , Mishiro Takuya , Chikawa Takashi , Soshi Shigeru 
Published: March 2018

Study Design:
This is a prospective multicenter comparison study.

Objective:
To measure the insertional torque (IT) for cervical vertebra lateral mass screw (LMS) fixation using the Magerl and Roy-Camille methods, at the discretion of the surgeon.

Summary of Background Data:
Current fixation methods for patients with preoperative cervical spine instability use LMSs; however, few studies have closely examined intraoperative IT. Patients’ bone quality was not measured.

Methods:
A total of 637 posterior cervical multiaxial screws were inserted for LMS (C3–C6) (Magerl technique, 423; Roy-Camille technique, 214) in 107 cases. Patients’ mean age was 66 years. Patients treated with the Magerl method were divided into 2 groups, with the men in the MM group and the women in the MF group. Similarly, patients treated with the Roy-Camille method were divided into 2 groups, with the men in the RM group and the women in the RF group. The contralateral cortex was penetrated, and the IT at cerclage was measured at the last time.

Results:
IT of the lateral mass screw was 53.8±22.4, 45.4±21, 45.5±16.9, and 34±16.4 cN.m in the MM group (258), MF group (165), RM group (163), and RF group (51), respectively. The MM group had a significantly higher IT than the other 3 groups, and the RM group had a significantly higher IT than the RF group. When the correlation between screw length and IT was evaluated, IT was significantly (P<0.05) higher with a longer screw by the Magerl method.

Conclusions:
The IT was higher with the Magerl method with a longer screw. Screw length and IT were not correlated with the Roy-Camille method; furthermore, the Roy-Camille method went through bilateral cortical bone perpendicularly, so that IT was determined by the fixation power in the cortical part of the bone, which was not thought to be affected by screw length.

Level of Evidence:
Level III.
Radiographic and Clinical Outcome of Silicate-substituted Calcium Phosphate (Si-CaP) Ceramic Bone Graft in Spinal Fusion Procedures
Authors: Alimi Marjan , Navarro-Ramirez Rodrigo , Parikh Karishma , Njoku Innocent , Hofstetter Christoph P. , Tsiouris Apostolos J. , Härtl Roger 
Published: March 2018

Study Design:
Retrospective cohort study.

Objective:
To evaluate the radiographic and clinical outcome of silicate-substituted calcium phosphate (Si-CaP), utilized as a graft substance in spinal fusion procedures.

Summary of Background Data:
Specific properties of Si-CaP provide the graft with negative surface charge that can result in a positive effect on the osteoblast activity and neovascularization of the bone.

Methods:
This study included those patients who underwent spinal fusion procedures between 2007 and 2011 in which Si-CaP was used as the only bone graft substance. Fusion was evaluated on follow-up CT scans. Clinical outcome was assessed using Oswestry Disability Index, Neck Disability Index, and the visual analogue scale (VAS) for back, leg, neck, and arm pain.

Results:
A total of 234 patients (516 spinal fusion levels) were studied. Surgical procedures consisted of 57 transforaminal lumbar interbody fusion, 49 anterior cervical discectomy and fusion, 44 extreme lateral interbody fusion, 30 posterior cervical fusions, 19 thoracic fusion surgeries, 17 axial lumbar interbody fusions, 16 combined anterior and posterior cervical fusions, and 2 anterior lumbar interbody fusion. At a mean radiographic follow-up of 14.2±4.3 months, fusion was found to be present in 82.9% of patients and 86.8% of levels. The highest fusion rate was observed in the cervical region. At the latest clinical follow-up of 21.7±14.2 months, all clinical outcome parameters showed significant improvement. The Oswestry Disability Index improved from 45.6 to 13.3 points, Neck Disability Index from 40.6 to 29.3, VAS back from 6.1 to 3.5, VAS leg from 5.6 to 2.4, VAS neck from 4.7 to 2.7, and VAS arm from 4.1 to 1.7. Of 7 cases with secondary surgical procedure at the index level, the indication for surgery was nonunion in 3 patients.

Conclusions:
Si-CaP is an effective bone graft substitute. At the latest follow-up, favorable radiographic and clinical outcome was observed in the majority of patients.

Level of Evidence:
Level—III.