bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intraoperative Neuromonitoring in Pediatric and Adult Spine Deformity Surgery
Authors: Strike Sophia A. , Hassanzadeh Hamid , Jain Amit , Kebaish Khaled M. , Njoku Dolores B. , Becker Daniel , Ain Michael C. , Sponseller Paul D. 
Published: March 2018

Study Design:
Review of techniques and description of institutional clinical experience.

Objective:
To provide a historical review and description of key neuromonitoring concepts, focusing on neurogenic motor-evoked potentials and descending neurogenic evoked potentials, and to review the authors’ experience with neuromonitoring techniques in children and adults undergoing spinal deformity surgery.

Summary of Background Data:
The original form of neuromonitoring, the Stagnara wake-up test, remains the “gold standard” for detecting true neurological deficits. Multiple newer modalities involving cortical and muscular monitoring, such as somatosensory evoked potentials and motor evoked potentials, have been developed and are widely used. Descending and neurogenic evoked potentials are becoming more common for neuromonitoring in patients undergoing spinal deformity surgery.

Methods:
A PubMed search for literature related to “neuromonitoring” was performed, and recent, as well as historical, articles were reviewed. Clinical experience regarding the use of neuromonitoring in adult and pediatric spinal deformity surgery was obtained from institutional experts.

Results:
Although not regularly used, the Stagnara wake-up test remains the gold standard for detecting neurological injury. Somatosensory evoked potentials measure signals transmitted from the periphery to the cortex and have historically been widely used but are limited by delay, poor localization, and the inability to detect damage to motor tracts. Motor evoked potentials continue to be used widely and measure muscular activity after cortical stimulation, but they are difficult to interpret in patients with underlying motor disorders and cannot be continuously monitored. Newer techniques such as descending neurogenic evoked potentials and neurogenic motor evoked potentials monitoring are used at some high-volume centers.

Conclusions:
Familiarity with the history of neuromonitoring in spinal deformity surgery and an understanding of the physiological systems used for neuromonitoring provide a framework from which spine surgeons can select appropriate monitoring for their patients.
Metastatic Spine Tumor Surgery
Authors: Kumar Naresh , Malhotra Rishi , Maharajan Karthikeyan , Zaw Aye S. , Wu Pang Hung , Makandura Milindu C. , Po Liu Gabriel Ka , Thambiah Joseph , Wong Hee-Kit 
Published: March 2018

Study Design:
Prospective cohort study.

Summary of Background Data:
Minimally invasive spinal surgery (MISS) has been gaining recognition in patients with metastatic spine disease (MSD). The advantages are reduction in blood loss, hospital stay, and postoperative morbidity. Most of the studies were case series with very few comparing the outcomes of MISS to open approaches.

Objective:
To evaluate and compare the clinical and perioperative outcomes of MISS versus open approach in patients with symptomatic MSD, who underwent posterior spinal stabilization and/or decompression.

Patients and Methods:
Our study included 45 MSD patients; 27 managed by MISS and 18 by open approach. All patients had MSD presenting with symptoms of neurological deficit, spinal instability, or both. Preoperative, intraoperative, and postoperative data were collected for comparison of the 2 approaches. All patients were followed up until the end of study period (maximum up to 4 years from time of surgery) or till their demise. The clinical outcome measures were pain control, neurological and functional status, whereas perioperative outcomes were blood loss, operative time, length of hospital stay, and time taken to initiate radiotherapy/chemotherapy after index surgery.

Results:
Majority of patients in both groups showed improvement in pain, neurological status, independent ambulation, and ECOG score in the postoperative period with no significant differences between the 2 groups. There was a significant reduction in intraoperative blood loss (621 mL less, P<0.001) in the MISS group. The average time to initiate radiotherapy after surgery was 13 days (range, 12–16 d) in MISS and 24 days (range, 16–40 d) in the open group. This difference was statistically significant (P<0.001). Operative time and duration of hospital stay were also favorable in the MISS group, although the differences were not significant.

Conclusions:
MISS is comparable with open approach demonstrating similar improvements in clinical outcomes, that is pain control, neurological and functional status. MISS approaches have also shown promising results due to lesser intraoperative blood loss and allowing earlier radiotherapy/chemotherapy.
Comparison of Long-term Differences in Dysphagia
Authors: Smucker Joseph D. , Bassuener Scott R. , Sasso Rick C. , Riew K. Daniel 
Published: March 2018

Study Design:
Retrospective cohort study.

Objective:
This study investigates the incidence of long-term dysphagia in cervical disc arthroplasty, and anterior cervical discectomy and fusion (ACDF) patients.

Summary of Background Data:
No long-term comparison of dysphagia between cervical arthroplasty and fusion patients has been published. Widely variable short-term postsurgical dysphagia rates have been reported.

Materials and Methods:
Cohorts for this study are patients with single-level cervical degenerative disc disease previously enrolled in a randomized clinical trial comparing cervical arthroplasty and ACDF. Subjective modified Bazaz Dysphagia Severity questionnaires were distributed to each patient at a minimum of 5 years postoperative for the long-term assessment. Dysphagia severity data were pooled to compare the rate of patients with dysphagia (grade>1) to asymptomatic (grade=1).

Results:
In the arthroplasty cohort, 15 of 22 (68%) patients completed long-term swallowing questionnaires with no reports of dysphagia. Eighteen of 25 (72%) ACDF patients completed questionnaires, with 5 of 18 (28%) reporting dysphagia. This is a statistically significant difference (P=0.042) favoring lower rates of long-term dysphagia after cervical arthroplasty at an average interval of 7 years postoperative (range, 5.5–8.5 y). No significant difference between rates of self-reported short-term dysphagia was noted with 12% (3/25) and 9% (2/22) in the ACDF and arthroplasty groups, respectively (P=0.56). All short-term dysphagia cases in the arthroplasty cohort reported complete resolution of symptoms within 12 months postoperative. In the ACDF cohort, persistent symptoms at 7 years were noted in all responding patients. Three ACDF patients reported new late-onset, which was not noted in the arthroplasty cohort.

Conclusions:
To date, these findings represent the longest reported follow-up interval comparing rates of dysphagia between randomized cohorts of cervical arthroplasty and fusion patients. Our study suggests that cervical arthroplasty is less likely than ACDF to cause sustained long-term or late-presenting dysphagia.
“Inline” Axial Reconstructed CT Scans Provide a Significantly Larger Assessment of C2 Pedicle Diameter for Screw Placement Compared With “Standard” Axial Scans
Authors: Vizurraga David E. , Rhee John M. , Borden Timothy C. , Mansour Ashton S. 
Published: March 2018

Study Design:
Radiologic analysis.

Objective:
The objective was to compare C2 pedicle diameter and screw feasibility on reconstructed axial computed tomography (CT) cuts created “Inline” (IL) with the intended pedicle screw tract versus unaltered “Standard” (STD) axial cuts.

Background Data:
Axial CT cuts through the C2 pedicle are commonly evaluated when planning pedicle screw fixation as medial aberrancies of the vertebral artery can significantly narrow pedicle diameter. STD axial CT cuts provided by radiology departments are typically formatted orthogonal to the long axis of the neck or the vertical plumb, which is often not IL with the axis of the intended C2 pedicle screw tract.

Materials and Methods:
A total of 89 cervical spine CT scans obtained by a single radiology department over 2 years (35 male, 54 female; mean age 64.9 y) were reviewed. STD axial cuts were not manipulated but were assessed as provided. IL axial cuts were created along the intended C2 pedicle screw tract using free, open-source DICOM viewer software. Inner and outer pedicle diameters were measured on axial cuts most closely approximating the isthmus of the intended tract.

Results:
On STD cuts, the mean outer and inner pedicle diameters were 5.05±1.45 and 2.01±1.31 mm, respectively. By contrast, IL measurements yielded significantly larger outer and inner diameters: 5.85±1.78 and 2.68±1.47 mm (P<0.01). IL measurement predicted a higher number of pedicles amenable to insertion of a 3.5 mm screw with safety margins of 1 to 3 mm.

Conclusions:
Reformatted IL axial cuts through the intended path of C2 pedicle screws provide significantly larger assessments of C2 pedicle diameter than those obtained on STD cuts. IL measurements predict C2 screw insertion feasibility in a substantially higher number of pedicles. As assessment of IL cuts may alter surgical decision-making at no added cost or radiation exposure, we suggest that they be obtained whenever considering C2 pedicle screw placement.
The Significance of the Trömner Sign in Cervical Spondylotic Myelopathy Patient
Authors: Chaiyamongkol Weera , Laohawiriyakamol Teeranan , Tangtrakulwanich Boonsin , Tanutit Pramot , Bintachitt Piyawat , Siribumrungwong Koopong 
Published: March 2018

Study Design:
This study is a diagnostic analysis.

Objective:
To investigate the diagnostic accuracy of Trömner sign in cervical spondylotic myelopathy (CSM), and how its presence correlates with the severity of myelopathy.

Summary of Background Data:
A clinical presentation of myelopathy corresponding with image findings is a current standard to diagnose CSM. Trömner sign is an alternative of well-known Hoffmann sign to detect CSM. Little is known about its diagnostic accuracy and how its presence correlates with the severity of CSM.

Materials and Methods:
Consecutive patients with clinical diagnosis of CSM and other cervical spondylosis–related problems were enrolled in either CSM group, cervical spondylotic radiculopathy group, or axial pain group. Normal volunteers and patients without spine-related issues were used as a control. All participants were examined for the presence of myelopathic signs. Magnetic resonance imaging studies of all participants were reviewed by a radiologist.

Results:
There were 85 participants included in the study. Diagnostic sensitivity was 76%, 94%, 76%, and 36% for Hoffmann sign, Trömner sign, inverted radial reflex, and Babinski sign, respectively. Trömner sign had relatively high sensitivity (95%) despite of mild degree of myelopathy. Negative predictive value was 60%, 85%, 59%, and 38% for Hoffmann sign, Trömner sign, inverted radial reflex, and Babinski sign, respectively. There were 63%–71% of patients in either axial pain group or cervical spondylotic radiculopathy group had positive Trömner sign. Most of CSM patients with cord signal changed had positive myelopathic sign. Regarding CSM patient without cord signal change, most of tests were negative except Trömner sign.

Conclusions:
High sensitivity (94%) and relatively high negative predictive value (85%) for Trömner sign indicate the usefulness of Trömner sign in ruling out CSM. High incidence of positive Trömner sign in presymptomatic cervical cord compression patients suggests Trömner sign could have a useful role in early detection of presymptomatic patients.
Failure to Launch
Authors: Hart Robert A. , DePasse J. Mason , Daniels Alan H. 
Published: March 2018

Study Design:
Spine surgeon survey.

Objective:
The objective was to investigate the failure of widespread adoption of lumbar total disk replacement (L-TDR) in the United States.

Summary of Background Data:
L-TDR has been available for use in the United States since 2005. L-TDR has not gained wide acceptance as a treatment for degenerative disk disease despite substantial investments in product development and positive results in randomized controlled trials.

Methods:
Estimates of the number of L-TDR procedures performed in the United States from 2005 to 2010 were calculated using the Nationwide Inpatient Sample database. Insurance policies were assessed for L-TDR coverage through Internet search. Finally, an 18-question survey regarding surgeons’ opinions toward L-TDR was distributed to the members of North American Spine Society.

Results:
The estimated number of primary L-TDR procedures performed in the United States decreased from 3650 in 2005 to 1863 in 2010, whereas revision L-TDR procedures increased from 420 to 499. Of 14 major insurers, 11 (78.6%) do not cover L-TDR. In total, 613 spine surgeons responded to the survey. Over half of respondents (51.1%, 313/612) have performed L-TDR, although only 44.6% (136/305) of initial adopters currently perform the surgery. However, 81.5% (106/130) of those currently performing L-TDR have been satisfied with the results. When asked about their perceptions of L-TDR, 65.0% (367/565) indicated a lack of insurance coverage for L-TDR in their region, 54.9% (310/565) worry about long-term complications, and 52.7% (298/565) worry about the technical challenges of revision.

Conclusions:
Despite early enthusiasm for L-TDR, wide adoption has not occurred. A primary reason for this failure seems to be a lack of insurance coverage, despite intermediate-term clinical success. In addition, surgeons continue to express concerns regarding long-term outcomes and the technical difficulties of revision. This case study of a failed surgical innovation may signal increasing involvement of payers in clinical decision-making and may be instructive to surgeons, policymakers, and manufacturers.
Unilateral Versus Bilateral Pedicle Screw Fixation in Transforaminal Lumbar Interbody Fusion
Authors: Liu Fubing , Feng Zhenzhou , Zhou Xiaogang , Liang Yun , Jiang Chun , Li Xilei , Li Zheng , Jiang Xiaoxing , Dong Jian 
Published: March 2018

Study Design:
A retrospective clinical study.

Objective:
This study sought to retrospectively compare the mid-term to long-term outcomes between unilateral pedicle screw (UPS) and bilateral pedicle screw (BPS) augmented transforaminal lumbar interbody fusion (TLIF) in lumbar degenerative diseases.

Summary of Background Data:
Recently, UPS fixation has been applied in TLIF, for its satisfactory clinical outcome, less implants and less invasiveness. However, only short-term outcome has been reported, the mid-term to long-term outcome has not been well characterized.

Materials and Methods:
From June 2007 to February 2011, 215 of 348 consecutive patients suffering from lumbar degenerative diseases were operated in our hospital and accomplished a minimum of 4-year follow-up. These patients were divided into 2 groups according to the operative techniques: UPS group (n=109), and bilateral pedicle screw group (n=106). Operative time, blood loss, length of hospital stay, hospital bill, fusion status, and complications were recorded and analyzed statistically. Visual analog scale, Oswestry disability index, and Japanese Orthopaedic Association scores were used to assess the preoperative and postoperative pain and functional outcome.

Results:
The mean follow-up duration was 52.2 months. A significant decrease occurred in operative time, blood loss, and hospital bill in unilateral group, compared with bilateral group (P<0.05). The average postoperative visual analog scale, Oswestry disability index, and Japanese Orthopaedic Association scores improved significantly in each group than the preoperative counterparts (P<0.05); however, there were no significant difference between groups at any follow-up time point (P>0.05). No statistically difference was detected regarding fusion rate and complication rate between the 2 groups (P>0.05), except the cage migration rate (P<0.05).

Conclusions:
UPS fixation could achieve satisfactory clinical outcome similar to bilateral fixation in TLIF at a mid-term to long-term follow-up. To avoid cage migration, bullet-shaped cages should not be used in the unilateral group.
Degenerative Spondylolisthesis in the Fifth Lumbar Vertebra and Radiographic Parameters
Authors: Chen Qian , Cao Lu , Bian Chong , Wang Hui-Ren , Lin Hong , Li Xi-Lei , Jiang Yun-Qi , Dong Jian 
Published: March 2018

Study Design:
A retrospective study.

Objective:
This study aimed to analyze the relationships between degenerative spondylolisthesis in the fifth lumbar vertebra (L5-DS) and radiographic parameters and to further determine the radiographic predictors of the development of L5-DS.

Summary of Background Data:
Degenerative lumbar spondylolisthesis (DLS) is a common degenerative disease of the spine; however, the correlations between L5-DS and radiographic parameters remain controversial.

Patients and Methods:
This retrospective case-control study was conducted in our hospital. Between 2011 and 2014, a total of 84 subjects with L5-DS were enrolled in the DLS group, and 56 healthy volunteers were recruited to the control group. A series of radiographic parameters, including the bone mineral density, disk degenerative index, disk height, L5 vertebral size (L5-VS), lumbar lordosis angle (LL), sacral slope angle (SS), pelvic incidence (PI), facet joint angulations (FJA) of the cephalad and caudad portions, and asymmetry of the FJA, were measured in both groups by 3 examiners.

Results:
The bone mineral density, disk degenerative index, disk height, L5-VS, LL, SS, PI, and FJA exhibited significant differences (P=0.014–0.045) between the DLS and control groups. Significant changes in the FJA of the cephalad and caudad portions in the L4–L5 and L5–S1 segments were observed between the 2 groups (P=0.00, 0.00), whereas no significant differences in the asymmetries of FJA were observed in the L4–L5 or L5–S1 segments (P=0.605–0.972). Among all of the parameters, the L5-VS (P=0.025), SS (P=0.020), LL (P=0.031), PI (P=0.014), and FJA (P=0.022) were identified as being associated with the DLS group by multiple logistic regression analysis.

Conclusions:
In this study, SS, LL, PI, and a more sagittal FJA were proven to be risk factors for L5-DS, whereas L5-VS was found to be a likely protective factor against L5-DS. These parameters should be considered predictors of L5-DS.
Impact of Inpatient Venous Thromboembolism Continues After Discharge
Authors: Li Alexander Y. , Azad Tej D. , Veeravagu Anand , Bhatti Inderpreet , Li Amy , Cole Tyler , Desai Atman , Ratliff John K. 
Published: March 2018

Study Design:
Propensity score matched retrospective study using a nationwide longitudinal database.

Objective:
To quantify the longitudinal economic impact of venous thromboembolism (VTE) complications in spinal fusion patients.

Summary of Background Data:
VTE is a rare and serious complication that may occur after spine surgery. The long-term socioeconomic impact understanding of these events has been limited by small sample sizes and a lack of longitudinal follow-up. We provide a comparative economic outcomes analysis of these complications.

Methods:
We identified 204,308 patients undergoing spinal fusion procedures in a national billing claims database (MarketScan) between 2006 and 2010. Cohorts were balanced using 50:1 propensity score matching and outcome measures compared at 6, 12, and 18 months postoperation.

Results:
A total of 1196 (0.6%) patients developed postoperative VTE, predominantly occurring following lumbar fusion (69.7%). Postoperative VTE patients demonstrated an increase in hospital length of stay (7.8 vs. 3.3 d, P<0.001) and a decreased likelihood of being discharged home (71% vs. 85%, P<0.001). A $26,306 increase in total hospital payments (P<0.001) was observed, with a disproportionate increase seen in hospital payments ($22,103, P<0.001), relative to physician payments ($1766, P=0.001).
At 6, 12, and 18 months postfusion, increased rates of readmission and follow-up clinic visits were observed. Delayed readmissions were associated with decreased length of stay (3.6 vs. 4.6 d, P<0.001), but increased total payments, averaging at $21,270 per readmission. VTE patients generated greater cumulative outpatient service payments, costing $8075, $11,134, and $13,202 more at 6, 12, and 18 months (P<0.001).

Conclusions:
VTEs are associated with longer hospitalizations, a decreased likelihood of being discharged home, and overall increases of hospital resource utilization and cost in inpatient and outpatient settings. VTE patients generate greater charges in the outpatient setting and are more likely to become readmitted at 6, 12, and 18 months after surgery, demonstrating a significant socioeconomic impact long after occurrence.

Level of Evidence:
Level III—therapeutic.
The Utility of Routinely Obtaining Postoperative Laboratory Studies Following a Minimally Invasive Transforaminal Lumbar Interbody Fusion
Authors: Ahn Junyoung , Massel Dustin H. , Mayo Benjamin C. , Hijji Fady Y. , Narain Ankur S. , Aboushaala Khaled , Bohl Daniel D. , Elboghdady Islam M. , DiBattista Jacob V. , Singh Kern 
Published: March 2018

Study Design:
This is a retrospective analysis.

Objective:
To test the hypothesis that there is limited utility in routinely obtaining postoperative laboratory values following minimally invasive transforaminal lumbar interbody fusion (MIS TLIF).

Background Data:
At many institutions, it is routine to obtain a complete blood count and basic metabolic profile (BMP) following a MIS TLIF. However, the utility of this practice has not been well characterized.

Methods:
A total of 332 consecutive patients who underwent a primary, 1-level MIS TLIF for degenerative spinal pathology between 2007 and 2013 were identified. Patients were stratified into low-risk and high-risk cohorts based upon risk for postoperative laboratory abnormalities. Inclusion criteria for the high-risk cohort were malignancy, complicated diabetes, renal failure, liver disease, hematologic disease, or significant intraoperative blood loss (>300 mL). Preoperative and postoperative hemoglobin (Hb), hematocrit, and BMP values were compared. Any interventions that were potentially related to laboratory values were identified.

Results:
Totals of 270 low-risk and 62 high-risk patients were identified. Mean postoperative Hb, hematocrit, blood urea nitrogen, sodium, potassium, and calcium values were decreased compared with preoperative values (P<0.001 for each) in both cohorts. Similar changes from preoperative levels were demonstrated in each cohort. No patients received blood product transfusion. Eleven low-risk (4.1%) and 5 high-risk patients (8.1%) received oral potassium supplementation. All patients who received potassium supplementation were asymptomatic. Most patients who were given potassium replacement consumed medications known to decrease serum potassium levels. No other interventions were performed in either group.

Conclusions:
Despite a significant decrease in mean Hb concentration following surgery, no patients required a transfusion. In total, 16 patients received potassium supplementation likely related to medication-related potassium deficits. Overall, these findings suggest that the utility of routinely obtaining a complete blood count or BMP following uncomplicated MIS TLIF may be limited except in the setting of select preoperative comorbidities and/or perioperative risk factors or events.

Level of Evidence:
Level III.