bluuebunny/crossref_metadata_2025_split huggingface dataset:
Screw Placement at the Apex Alters Surgical Outcomes of Moderate Lenke 1 Adolescent Idiopathic Scoliosis
Authors: Zheng Xin , Qian Bang-ping , Liu Zhen , Sun Xu , Zhu Ze-zhang , Wang Bin , Yu Yang , Qiu Yong 
Published: March 2018

Study Design:
Retrospective study.

Objective of the Study:
The objective was to investigate the effect of apical pedicle screw placement on surgical outcomes of Lenke 1 adolescent idiopathic scoliosis (AIS).

Summary of the Background Data:
Pedicle screw instrumentation achieves satisfactory correction of scoliosis in thoracic AIS patients, but the effect of apical screw placement is unclear.

Materials and Methods:
Lenke 1 AIS patients with all pedicle screw instrumentation between January 2009 and January 2011 were reviewed. According to the presence of apical vertebra instrumentation, 38 patients (group A) were identified without apical screw placement. 25 patients (group B) instrumented with both concave, and convex apical screws and 50 patients (group C) with either concave or convex apical pedicle screw instrumentation were also enrolled according to matched age and Cobb angles. Cobb angle correction, apical vertebral derotation, misplacement of apical screws, functional outcomes, and patient satisfaction were evaluated.

Results:
Demographic parameters and preoperative Cobb angle, curve flexibility, and apex rotation were similar among the 3 groups (P>0.05). Postoperatively, there was no significant difference regarding the number of fused vertebrae, Cobb angle correction rate, or loss of correction. However, the degree of apical vertebral derotation was significantly lower in group A (17.8%) than in groups B (49.1%) and C (34.3%) (P<0.001). In group B, 6 screws inserted on the concavity and 5 on the convexity of the apex were identified as malpositioned; whereas in group C, 3 on the concavity and 2 on the convexity were malpositioned screws. Self-image and satisfaction were highest for patients in group B.

Conclusions:
For patients with moderate Lenke 1 AIS (Cobb angle, 50–70 degrees), the insertion of apical pedicle screws did not significantly improve curve correction, but it had a marked positive effect on the derotation of apical vertebrae, subsidence of the rib hump, and patient satisfaction.
Comparison of Curvature Between the Zero-P Spacer and Traditional Cage and Plate After 3-Level Anterior Cervical Discectomy and Fusion
Authors: Chen Yuanyuan , Liu Yang , Chen Huajiang , Cao Peng , Yuan Wen 
Published: March 2018

Study Design:
A retrospective study.

Objective:
To compare clinical and radiologic outcomes of 3-level anterior cervical discectomy and fusion between a zero-profile (Zero-P) spacer and a traditional plate in cases of symptomatic cervical spine spondylosis.

Summary of Background Data:
Anterior cervical decompression and fusion is indicated for patients with anterior compression or stenosis of the spinal cord. The Zero-P spacers have been used for anterior cervical interbody fusion of 1 or 2 segments. However, there is a paucity of published clinical data regarding the exact impact of the device on cervical curvature of 3-level fixation.

Methods:
Clinical and radiologic data of 71 patients undergoing 3-level anterior cervical discectomy and fusion from January 2010 to January 2012 were collected. Zero-P spacer was implanted in 33 patients, and in 38 cases stabilization was accomplished using an anterior cervical plate and intervertebral cage. Patients were followed for a mean of 30.8 months (range, 24–36 mo) after surgery. Fusion rates, changes in cervical lordosis, and degeneration of adjacent segments were analyzed. Dysphagia was assessed using the Bazaz score, and clinical outcomes were analyzed using the Neck Disability Index and Japanese Orthopedic Association scoring system.

Results:
Neurological outcomes did not differ significantly between groups. Significantly less dysphagia was seen at 2- and 6-month follow-up in patients with the Zero-P implant (P<0.05); however, there was significant less cervical lordosis and the lordosis across the fusion in patients with the Zero-P implant (both P<0.05). Degenerative changes in the adjacent segments occurred in 4 patients in the Zero-P group and 6 patients in the standard-plate group (P=0.742); however, no revision surgery was done.

Conclusions:
Clinical results for the Zero-P spacer were satisfactory. The device is superior to the traditional plate in preventing postoperative dysphagia; however, it is inferior at restoring cervical lordosis. It may not provide better sagittal cervical alignment reconstruction in 3-level fixation. Prospective randomized trials with more patients and longer follow-up periods are required to confirm these observations.
Complications Related to the Recombinant Human Bone Morphogenetic Protein 2 Use in Posterior Cervical Fusion
Authors: Takahashi Shinji , Buser Zorica , Cohen Jeremiah R. , Roe Allison , Myhre Sue L. , Meisel Hans-Joerg , Brodke Darrel S. , Yoon S. Tim , Park Jong-Beom , Wang Jeffrey C. , Youssef Jim A. 
Published: March 2018

Study Design:
A retrospective cohort study.

Objective:
To compare the complications between posterior cervical fusions with and without recombinant human bone morphogenetic protein 2 (rhBMP2).

Summary of Background Data:
Use of rhBMP2 in anterior cervical spinal fusion procedures can lead to potential complications such as neck edema, resulting in airway complications or neurological compression. However, there are no data on the complications associated with the “off-label” use of rhBMP2 in upper and lower posterior cervical fusion approaches.

Materials and Methods:
Patients from the PearlDiver database who had a posterior cervical fusion between 2005 and 2011 were identified. We evaluated complications within 90 days after fusion and data was divided in 2 groups: (1) posterior cervical fusion including upper cervical spine O-C2 (upper group) and (2) posterior cervical fusion including lower cervical spine C3–C7 (lower group). Complications were divided into: any complication, neck-related complications, wound-related complications, and other complications.

Results:
Of the 352 patients in the upper group, 73 patients (20.7%) received rhBMP2, and 279 patients (79.3%) did not. Likewise, in the lower group of 2372 patients, 378 patients (15.9%) had surgery with rhBMP2 and 1994 patients (84.1%) without. In the upper group, complications were observed in 7 patients (9.6%) with and 34 patients (12%) without rhBMP2. In the lower group, complications were observed in 42 patients (11%) with and 276 patients (14%) without rhBMP2. Furthermore, in the lower group the wound-related complications were significantly higher in the rhBMP2 group (23 patients, 6.1%) compared with the non-rhBMP2 group (75 patients, 3.8%).

Conclusions:
Our data showed that the use of rhBMP2 does not increase the risk of complications in upper cervical spine fusion procedures. However, in the lower cervical spine, rhBMP2 may elevate the risk of wound-related complications. Overall, there were no major complications associated with the use of rhBMP2 for posterior cervical fusion approaches.

Level of Evidence:
Level III.
Changes in Pelvic Incidence, Pelvic Tilt, and Sacral Slope in Situations of Pelvic Rotation
Authors: Jin Hai-Ming , Xu Dao-Liang , Xuan Jun , Chen Jiao-Xiang , Chen Kai , Goswami Amit , Chen Yu , Kong Qiu-Yan , Wang Xiang-Yang 
Published: March 2018

Study Design:
Digitally reconstructed radiograph-based study.

Objective:
Using a computer-based method to determine what degree of pelvic rotation is acceptable for measuring the pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS). The effectiveness of a geometrical formula used to calculate the angle of pelvic rotation proposed in a previous article was assessed.

Summary of Background Data:
It is unclear whether PI, PT, and SS are valid with pelvic rotation while acquiring a radiograph.

Materials and Methods:
Ten 3-dimensionally reconstructed models were established with software and placed in a neutral orientation to orient all of the bones in a standing position. Next, 140 digitally reconstructed radiographs were obtained by rotating the models around the longitudinal axis of each pelvis in the software from 0 to 30 degrees at 2.5-degree intervals. PI, PT, and SS were measured. The rotation angle was considered to be acceptable when the change in the measured angle (compared with the “correct” position) was <6 degrees. The rotation angle (α) on the images was calculated by a geometrical formula. Consistency between the measured value and the set angle was assessed.

Results:
The acceptable maximum angle of rotation for reliable measurements of PI was 17.5 degrees, and the changes in PT and SS were within an acceptable range (<6 degrees) when the pelvic rotation increased from 0 to 30 degrees. The effectiveness of the geometrical formula was shown by the consistency between the set and the calculated rotation angles of the pelvis (intraclass correlation coefficient=0.99).

Conclusions:
Our study provides insight into the influence of pelvic rotation on the PI, PT, and SS. PI changes with pelvic rotation. The acceptable maximum angle for reliable values of PI, PT, and SS was 17.5 degrees, and the rotation angle of the pelvis on a lateral spinopelvic radiograph can be calculated reliably.
Measurement of Spinopelvic Parameters on Standing Lateral Lumbar Radiographs
Authors: Chung Nam-Su , Jeon Chang-Hoon , Lee Han-Dong , Won Suk-Hyeong 
Published: March 2018

Study Design:
This was a radiographic validity and reliability study.

Objective:
We assessed the validity and reliability of measurements made on standing lateral lumbar radiographs, compared with lateral whole-spine radiographs, for evaluating spinopelvic parameters and lumbar lordosis (LL).

Summary of Background Data:
A lateral whole-spine radiograph is the gold standard image for measurement of spinopelvic parameters. However, little evidence is available on the reliability of measurements made on such radiograph. A standing lateral lumbar radiograph is routinely obtained from patients with back pain and/or a disability. This image can include upper end plate of L1 vertebra, sacral dome and both femoral heads. Thus, this radiograph can be used for evaluation of spinopelvic parameters.

Materials and Methods:
We randomly selected 50 sets of digital radiographs (standing lateral lumbar and lateral whole-spine radiographs) from our database. Three experienced spinal surgeons independently measured LL, pelvic incidence, pelvic tilt, and sacral slope on all images. A paired t test and Pearson correlation was used to analyze the validity of the lateral lumbar radiograph. Interobserver and intraobserver reliabilities were assessed by intraclass correlation coefficient.

Results:
Thee spinopelvic parameters and LL measured on lateral lumbar radiographs were similar to those measured on lateral whole-spine radiographs (All P-values >0.05, Pearson correlation coefficients, 0.807–0.969). The intraobserver and interobserver reproducibilities of both measurement types were good-to-excellent.

Conclusions:
Spinopelvic parameters and LL values measured on lateral lumbar radiographs were reproducibly similar to those measured on lateral whole-spine radiographs. Use of a standing lateral lumbar radiograph is reasonable when spinopelvic parameters and LL are to be measured.
Comparison of Decompression With and Without Fusion for Patients With Synovial Facet Cysts
Authors: van Dijke Maarten , Janssen Stein J. , Cha Thomas D. , Wood Kirkham B. , Borges Lawrence F. , Harris Mitchel B. , Bono Christopher M. , Schwab Joseph H. 
Published: March 2018

Study Design:
This is a retrospective study.

Objective:
To compare (1) recurrence of radiculopathy and (2) back pain after decompression with and without fusion for patients with a symptomatic synovial cyst.

Background:
Previous work described favorable outcomes following cyst excision with and without fusion. Because of the association of facet cysts with spinal instability it is hypothesized that a decompression with fusion will lead to better outcomes. However, previous studies present contradicting results.

Methods:
We included 314 consecutive patients that underwent operative treatment for a facet cyst between 2003 and 2013 at 2 tertiary spine referral centers: 224 (71%) underwent decompression without fusion (35% spondylolisthesis), 90 (29%) underwent decompression with fusion (63% spondylolisthesis). Baseline data were compared between the groups. Bivariate log-rank analysis was used to compare outcomes between groups, followed by multivariable Cox regression analysis accounting for differences in baseline characteristics.

Results:
Patients undergoing decompression with fusion presented with a higher incidence of back pain (P=0.004) and spondylolisthesis (P<0.001), had more often bilateral decompressions (P<0.001), more facetectomies (P<0.001), and more levels of decompression (P=0.004) than those who underwent decompression alone. We found a difference in recurrence of radiculopathy (no fusion: 25% vs. fusion: 9.4%, P=0.029) in bivariate analysis. However, this difference did not hold when accounting for confounders (hazard ratio, 0.50, 95% confidence interval, 0.19–1.31, P=0.16). There was no difference in recurrence of back pain in bivariate (no fusion: 29% vs. fusion: 22%, P=0.51) and multivariable analysis (hazard ratio 0.51, 95% confidence interval, 0.23–1.14, P=0.10).

Conclusions:
We found, with the numbers evaluated, no difference in recurrence of radiculopathy or back pain between patients undergoing decompression with or without fusion after accounting for confounders. The decision for fusion should be considered in light of the extent of decompression and the existence of other pathology.

Level of Evidence:
Level III—therapeutic study.
Sublaminar Decompression
Authors: Kebaish Khaled M. , Elder Benjamin D. , Lo Sheng-fu L. , Witham Timothy F. 
Published: March 2018

Study Design:
Technical report and case illustration.

Objective:
To review the rationale and steps for a sublaminar decompression in the setting of adult deformity surgery and in degenerative spondylosis.

Summary of Background Data:
Several variations of lumbar laminotomy and posterior decompressions have been reported, although these are primarily in the setting of isolated lumbar stenosis, and often focus on treatment of central stenosis.

Materials and Methods:
Our operative technique is illustrated and 1 patient with a 1-year follow-up is presented to further describe this surgical approach.

Results and Surgical Techniques:
The patient underwent a lumbar decompression and fusion procedure. A sublaminar decompression with bilateral foraminotomies was performed at L4–L5, combined with instrumented posterior fusion.

Conclusions:
The presented sublaminar decompression technique allows for adequate decompression of the central canal, lateral recess, and neural foramina while providing maximum bone surface area for posterolateral as well as posterior fusion.
The Effect of Dynamic Versus Static Plating Systems on Fusion Rates and Complications in 1-Level and/or 2-Level Anterior Cervical Discectomy and Fusion
Authors: Schroeder Gregory D. , Kepler Christopher K. , Hollern Douglas A. , Rodrigues-Pinto Ricardo , Kurd Mark F. , Wilson Jefferson R. , Maltenfort Mitchell G. , Paul Jonathan T. , Fleischman Andrew N. , Dwight Kathryn , Millhouse Paul W. , Vaccaro Alexander R. 
Published: March 2018

Study Design:
A systematic review.

Objective:
To determine the effect of plate design on fusion rates in patients undergoing a 1- and 2-level anterior cervical discectomy and fusion (ACDF).

Methods:
Articles published between January 1, 2002 and January 1, 2015 were systematically reviewed to determine the fusion rate of 1- and 2-level ACDFs using either a fully constrained or semiconstrained locking plate. Additional variables that were collected included the number of levels, the type of graft/cage used, the study design, the method for determining fusion, and complications.

Results:
Fifty-two articles and 3053 patients were included. No significant difference in the fusion rate for 1- and 2-level ACDF using a fully constrained plate (96.1%) and a semiconstrained plate (95.29%) was identified (P=0.84). No difference (P=0.85) in the total complication rate between fully constrained plates (3.20%) and semiconstrained plates (3.66%), or the rate of complications that required a revision (2.17% vs. 2.41%, P=0.82) was identified. However, semiconstrained plates had a nonsignificant increase in total dysphagia rates (odds ratio=1.660, P=0.28) and short-term dysphagia rates (odds ratio=2.349, P=0.10).

Conclusions:
In patients undergoing a 1- or 2-level ACDF, there is no significant difference in the fusion or complication rate between fully constrained plates and semiconstrained plates.

Level of Evidence:
Level II—systematic review.
Comparing the Effectiveness of Sagittal Balance, Foraminal Stenosis, and Preoperative Cord Rotation in Predicting Postoperative C5 Palsy
Authors: Chugh Arunit J.S. , Weinberg Douglas S. , Alonso Fernando , Eubanks Jason D. 
Published: March 2018

Study Design:
Retrospective cohort review.

Objective:
To determine whether preoperative cord rotation is independently correlated with C5 palsy when analyzed alongside measures of sagittal balance and foraminal stenosis.

Summary of Background Data:
Postoperative C5 palsy is a well-documented complication of cervical procedures with a prevalence of 4%–8%. Recent studies have shown a correlation with preoperative spinal cord rotation. There have been few studies, however, that have examined the role of sagittal balance and foraminal stenosis in the development of C5 palsy.

Methods:
A total of 77 patients who underwent cervical decompression—10 of whom developed C5 palsy—were reviewed. Sagittal balance was assessed using curvature angle and curvature index on radiographs and magnetic resonance image (MRI). Cord rotation was assessed on axial MRI. C4–C5 foraminal stenosis was assessed on sagittal MRI using area measurements and a grading scale. Demographics and information on surgical approach were gathered from chart review. Correlation with C5 palsy was performed by point-biserial, χ2, and regression analyses.

Results:
Point-biserial analysis indicated that only cord rotation showed significance (P<0.01). There was no statistical significance shown with surgical approach, sex, or age. In addition, changes in sagittal balance did not correlate with presence of C5 palsy. Logistic regression model yielded cord rotation as the only significant independent predictor of C5 palsy. For every degree of axial cord rotation, the likelihood ratio for suffering a C5 palsy was 3.93 (95% confidence interval, 2.01–8.66; P<0.05).

Conclusions:
This supports the independent capability of preoperative cord rotation to predict postoperative C5 palsy. Lack of correlation with measures of neuroforaminal stenosis potentially points to mechanisms other than direct compression as the etiology. In addition, the lack of correlation with postoperative changes in sagittal balance hints that measures of curvature angle and curvature index may not be appropriate to accurately predict this complication.

Level of Evidence:
Level 3.
Predictive Factors for Postoperative Follow-up: Which Patients are Prone to Loss to Follow-up After Spinal Surgery?
Authors: Ha Kee-Yong , Kim Sang-Il , Kim Young-Hoon , Kim Young-Ho , Oh In-Soo 
Published: March 2018

Study Design:Retrospective cohort study.Objective:To find out the predictive factors for the failure to follow-up in patients who underwent spinal surgery.Summary of Background Data:Causes for loss to follow-up range from geographical accessibility to dissatisfaction with surgeons. There were few reports that investigated loss to follow-up after spinal surgery.Methods:A total of 649 patients who underwent laminectomy and 193 patients who underwent L4–L5 fusion from August 2006 to August 2013 were enrolled in this retrospective study. In each surgical group, demographic data and comorbidities as assessed by the Charlson index were investigated and analyzed for correlation with follow-up. The between-group difference of failure to follow-up was also evaluated.Results:The fusion group (n=193) was more likely to follow-up and the between-group difference was statistically significant (P=0.047). In the laminectomy group (n=649), 271 patients (41.8%) made regular hospital visits. Those who were male, had a spouse, or had fewer comorbidities were less prone to loss to follow-up (P<0.001). Other parameters including age, number of spinal segments operated on during surgery, distance from home to hospital, income, education level, and whether or not patients exercised were also significantly correlated with follow-up compliance (P>0.05). In contrast, 51.8% (n=100) of patients who underwent fusion had regular follow-ups. The fusion group showed a statistical difference in follow-up rate based only on sex (P=0.002).Conclusions:Our study shows that patients who underwent decompression alone were less likely to attend follow-up than were patients who underwent fusion surgery. Whereas the factors correlated with loss to follow-up after laminectomy alone were sex, marital status, and number of comorbidities, the only predictor after fusion was male sex. Sex was the only shared risk factor for loss to follow-up.Level of Evidence:Level III.
The Influence of Single-level Versus Multilevel Decompression on the Outcome in Multisegmental Lumbar Spinal Stenosis
Authors: Ulrich Nils H. , Burgstaller Jakob M. , Held Ulrike , Winklhofer Sebastian , Farshad Mazda , Pichierri Giuseppe , Steurer Johann , Porchet François 
Published: March 2018

Study Design:
This is prospective multicenter cohort study.

Objective:
To assess whether patients with confirmed multisegmental lumbar spinal stenosis benefit more from a single-level or a multilevel decompression.

Summary of Background Data:
In multisegmental lumbar spinal stenotic cases, the decision as to how many levels of stenosis need to be operated to achieve the best possible clinical outcome is still unknown and remains a controversy between spine surgeons.

Materials and Methods:
Patients of the Swiss Lumbar Stenosis Outcome Study (LSOS) with confirmed multisegmental LSS undergoing first-time decompression without fusion were enrolled in this study. The main outcomes of this study were Spinal Stenosis Measure (SSM) symptoms and function over time, measured at baseline, 6, 12, and 24 months follow-up. Further outcomes of interest were changes in SSM, numeric rating scale, feeling thermometer, the EQ-5D-EL, and the Roland and Morris disability questionnaire from baseline to 6, 12, and 24 months.

Results:
After 12 months, a total of 141 patients met the inclusion criteria; of these, 33 (23%) underwent a single-level and 108 (77%) a multilevel decompression. Multilevel decompression was associated with a significantly less favorable SSM symptoms and function score, respectively, as compared with single-level decompression. In all further outcomes of interest single-level as well as multilevel patients improved over time.

Conclusions:
Our study showed that in multisegmental stenotic cases a single-level decompression was associated with a significantly more favorable SSM symptoms and function score, respectively, as compared with multilevel decompression. This study provides evidence that in multisegmental stenotic cases a single-level decompression might be sufficient to improve patient’s symptoms and function.