bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biomechanics—Hot Topics Part I
Authors: Bottlang Michael , Lorich Dean G. , Dvorzhinskiy Aleksey , Gausden Elizabeth , Slobogean Gerard P. , Schemitsch Geoffrey W. , Sanders David W. , Schemitsch Emil H. 
Published: February 2018

Summary:
This study summarizes presentations of a symposium on biomechanically related hot topics of the 2015 Basic Science Focus Forum. Each topic emphasizes a biomechanical challenge common to all 4 of these presentations: an ideal fixation technique should deliver ample stability and sufficient flexibility to prevent fixation failure and to restore normal function.
Absolute Versus Relative Fracture Fixation: Impact on Fracture Healing
Authors: Norris Brent L. , Lang Gerald , Russell Thomas A. (Toney) , Rothberg David L. , Ricci William M. , Borrelli Joseph 
Published: February 2018

Summary:
The goals of all orthopaedic surgeons treating fractures are, and will remain, obtaining union of the fracture with a well-aligned and functional limb while minimizing the risk of complications. This requires us to understand how the biomechanical environment of the fracture affects healing and to be able to discern which mechanical environment is preferred over another. Understanding the spectrum of stability imparted by our current surgical devices is paramount to giving our patients the best opportunity to heal and recover from their injury. Gone are the simplistic views of plates and screws being applied for absolute stability and nails and external fixators being applied for relative stability. This review sheds new light on how the use of different implants provides the appropriate stability to encourage fracture healing and limit the risk of complication and loss of function.
What Is Important Besides Getting the Bone to Heal? Impact on Tissue Injury Other Than the Fracture
Authors: Gardner Michael J. , Higgins Thomas A. , Harvin William H. , Stannard James P. , Lee Mark A. , Crist Brett D. 
Published: February 2018

Summary:
Fracture surgeons do a great job of managing bone issues, but they may overlook the associated soft tissue injuries that play a significant role in the final outcome after musculoskeletal injury. The soft tissue reconstruction ladder can help guide reconstructive procedures based on the least complex procedure that allows the best chance of fracture healing. Muscle injury, volume loss, and deconditioning occur with traumatic injury and during the recovery phase. Neuromuscular stimulation, nutrition, and strength training are potential ways to aid in recovery. Complex periarticular knee injuries have a high rate of associated soft tissue injuries that may affect outcome if associated with knee instability. Identifying and addressing these injuries can increase the likelihood of a good outcome. Articular cartilage loss can make articular reconstruction impossible. Large fresh osteoarticular allografts can be a reconstructive option. Addressing all the damaged structures involved with a fracture may be the next step in improving patient outcomes.
Biomechanics—Hot Topics Part II
Authors: Finkemeier Christopher , Adams John D. , Bernstein Mitchell , Lee Mark A. , Harvey Ed , Crist Brett D. 
Published: February 2018

Summary:
Orthopaedic surgery and biomechanics are intimately partnered topics in medicine. Biomechanical principles are used to design implants and fashion treatment protocols. Although it would seem that biomechanical principles in the design of fixation devices and fracture repair constructs have been already finalized, there are several points of controversy remaining. New technology has raised new questions, while at the same time, we still do not fully understand simple clinical principles such as time of fracture healing depending on the construct used. This review looks at several of these current controversies to better understand what work is needed in fracture care going forward.
Fracture Healing Adjuncts–The World's Perspective on What Works
Authors: Giannoudis Peter V. , Krettek Christian , Lowenberg David W. , Tosounidis Theodoros , Borrelli Joseph 
Published: February 2018

Summary:
Treatment of bone defects remains a challenging clinical problem. Despite our better understanding of bone repair mechanisms and advances made in microsurgical techniques and regenerative medicine, the reintervention rates and morbidity remain high. Surgical techniques such as allograft implantation, free vascularized fibular graft, distraction osteogenesis, loaded titanium cages, and the induced membrane technique continue to evolve, but the outcome can be affected by a number of parameters including the age of the patient, comorbidities, systemic disorders, the location of the defect, and the surgeon's preference and experience. In the herein article, a brief summary of the most currently used techniques for the management of bone defects is presented.
Risk Factors of Impaired Pulmonary Function in Arthrogryposis Multiplex Congenital Patients With Concomitant Scoliosis
Authors: Li Yetian , Sheng Fei , Xia Chao , Xu Leilei , Qiu Yong , Zhu Zezhang 
Published: February 2018

Study Design.
A retrospective study.

Objective.
To investigate the severity of pulmonary function impairment for arthrogryposis multiplex congenital (AMC) patients with concomitant scoliosis and to determine risk factors associated with the impaired pulmonary function in these patients.

Summary of Background Data.
AMC patients are generally believed to have impaired pulmonary function. However, the severity of respiratory morbidity and the associated risk factors have not been reported.

Methods.
The pulmonary function tests data including the percentage predicted values of forced vital capacity (%FVC), forced expiratory volume in 1 second (%FEV1), and the ratio of FEV1 to FVC (%FEV1/FVC) were reviewed and compared for 48 AMC patients with secondary scoliosis and 48 patients with adolescent idiopathic scoliosis. The radiographic parameters of coronal and sagittal plane deformities and body mass index (BMI) were measured and correlated with impaired pulmonary function in these AMC patients.

Results.
AMC patients with concomitant scoliosis had significant lower mean %FVC, %FEV1, and %FEV1/FVC than adolescent idiopathic scoliosis patients (48.8 vs. 70.3 for %FVC, P < 0.001; 45.3 vs. 69.7 for %FEV1, P < 0.001; 92.1 vs. 96.9 for %FEV1/FVC, P < 0.05, respectively). Seventy percent of AMC patients had severe pulmonary function impairment. A positive correlation was found between BMI and %FVC and %FEV1 (P < 0.01) and between hypokyphosis and %FVC and %FEV1 (P < 0.05). A negative correlation was found between coronal angle and pulmonary function (P < 0.05). Multiple regression analysis showed that all of the three variables were independent predictors associated with a reduced pulmonary function. With a combination of these variables, the multiple regression model could account for 38.7% of the variance in %FVC and 41.5% in %FEV1.

Conclusion.
There exists severe impairment of pulmonary function in AMC patients with concomitant scoliosis. The scoliotic curve, hypokyphosis, and BMI were independent risk factors associated with the pulmonary dysfunction in these patients. As the majority of the variability of impaired pulmonary function tests are still poorly understood, more risk factors await to be uncovered in future studies.

Level of Evidence: 4
Effects of Ultra-early Hyperbaric Oxygen Therapy on Femoral Calcitonin Gene-Related Peptide and Bone Metabolism of Rats With Complete Spinal Transection
Authors: Liu Min , Chen Huan , Tong Min , Zhou Jinping , Wu Xiyu 
Published: February 2018

Study Design.
Seventy-five Sprague-Dawley rats were randomly divided into sham, complete spinal cord transection (CSCT) and hyperbaric oxygen (HBO) groups. Among them, rats in HBO group were further divided into 3 hours group (HBO1) and 12 hours group (HBO2).

Objective.
To study the effects of ultra-early HBO therapy on femoral calcitonin gene–related peptide (CGRP) and bone metabolism of rats with CSCT.

Summary of Background Data.
Complete spinal cord injury (SCI) is still an unresolved problem in clinical practice. Studies on changes in (calcitonin gene-related peptide) CGRP and bone metabolism and osteoporosis prevention after SCI have important clinical significance.

Methods.
Rats in the sham group underwent laminectomy alone, whereas rats in the other three groups underwent laminectomy and CSCT at the level of the 10th thoracic vertebra. Six weeks after operation, rat blood samples and femoral samples from CSCT area were taken and prepared for immunohistochemical staining of CGRP, quantitative polymerase chain reaction (qPCR) of CGRP mRNA, enzyme-linked immunosorbent assay (ELISA) for the levels of serum bone–specific alkaline phosphatase (sBAP), serum osteocalcin (sOC), serum type-I collagen amino-terminal peptide (sNTX), and urinary deoxypyridinoline (uDPD). These data were statistically analyzed using paired LSD or Tamhane.

Results.
The number of CGRP-positive cells and expression of CGRP mRNA in femur were significantly reduced, and the levels of sBAP, sOC, sNTX, and uDPD were significantly increased in CSCT, HBO1, and HBO2 groups than in the sham group, (P < 0.05–0.01). In addition, the number of CGRP-positive cells, expression of CGRP mRNA in femur, and the levels of sBAP and sOC were significantly enhanced, but the levels of sNTX and uDPD were significantly lowered in HBO1 group than in HBO2 and CSCT groups (P < 0.05).

Conclusion.
Ultra-early HBO therapy could improve bone turnover, promote bone formation, and prohibit bone resorption by enhancing CGRP synthesis in the sensory neurons in posterior horn of spinal cord.

Level of Evidence: N/A
Biomechanical Comparison of Four Different Atlantoaxial Posterior Fixation Constructs in Adults
Authors: Chun Dong Hyun , Yoon Do Heum , Kim Keung Nyun , Yi Seong , Shin Dong Ah , Ha Yoon 
Published: February 2018

Study Design.
Finite element analysis.

Objective.
To compare the biomechanical stability imparted to the C1 and C2 vertebrae by the transarticular (TA), C1 lateral mass (LM)-C2 pedicle (PS), C1LM-C2 pars, and C1LM-C2 translaminar (TL) screw fixation techniques.

Summary of Background Data.
Cadaveric biomechanical studies of several atlantoaxial posterior fixation techniques have been performed, showing significant heterogeneity in biomechanical properties among the studies.

Methods.
From computed tomography images, a nonlinear intact three-dimensional C1–2 finite element model was developed and validated. Four finite element models were reconstructed from different C1–2 fixation techniques. The range of motion (ROM) and maximum von Misses stresses for the four screw techniques were compared under flexion, extension, lateral bending, and axial rotation.

Results.
C1LM-C2PS showed the greatest decrease in ROM with flexion/extension and lateral bending. C1–2TA and C1LM-C2 pars showed less ROM reduction than the other techniques, in flexion/extension. C1LM-C2TL showed the least decrease in ROM during axial rotation. For C1–2TA, the maximum stress was in the C1–2 joint region. In the C1LM-C2PS, the C1 rod head, C2 pars screw, and C2TL screw were stressed at the C2 rod head. The maximal von Mises stress on the C1–2TA at the C1–2 joint site was the highest at flexion/extension, whereas the C1LM-C2PS had the lowest stress on the screw at flexion/extension and lateral bending. The C1LM-C2TL showed the highest stress in axial rotation and lateral bending.

Conclusion.
In this study, C1LM-C2PS fixation was the most stable technique. If surgeons have to use other fixation methods besides the C2 pedicle screw, they need to be aware that additional fixation or postoperative immobilization may be required to achieve ROM restriction. Careful observation at the maximum stress site on the screw including screw loosening, screw-bone interface disruption or screw fracture will be necessary during follow-up imaging examinations (x-ray and computed tomography scan) after atlantoaxial fixation.

Level of Evidence: N/A
Back Pain and Co-occurring Conditions
Authors: Badley Elizabeth M. , Millstone Dov B. , Perruccio Anthony V. 
Published: February 2018

Study Design.
Cross-sectional population-level health survey.

Objective.
To describe the frequency of co-occurring conditions with back pain; to identify risk factors for back pain controlling for co-occurring conditions; and to examine the association between back pain and individual co-occurring conditions.

Summary of Background Data.
Back pain shares risk factors with a range of other conditions. Most studies have considered risk factors for back pain without taking into account the potential influence of co-occurring conditions.

Methods.
Analysis of the 2013 Canadian Community Health Survey (n = 61,854, age ≥15 yr). Back pain status and co-occurring conditions were determined from questions about long-term health conditions diagnosed by a health profession. Multivariable log-Poisson regression analysis was used to assess the adjusted association of back pain with demographic and lifestyle characteristics and co-occurring conditions.

Results.
The population prevalence of reported back pain was 19.3%. Most (71%) reported at least one co-occurring condition. Most frequently reported were arthritis (35%), high blood pressure (26%), migraine (18%), and mood disorders (14%). Following the addition of co-occurring condition count to the regression model, being female and being overweight/obese were no longer significantly associated with back pain, and the associations with ages 45 to 54 years and older, low-income, smoking, and being physical inactive were significantly attenuated. The highest prevalence ratio, 3.32 (95% confidence interval: 3.06–3.59), was for 3+ co-occurring conditions. In multivariable regression all but a few individual chronic conditions remained significant associated with back pain.

Conclusion.
Established risk factors for back pain may be largely a reflection of shared risk factors with co-occurring conditions. The high frequency of co-occurring conditions likely reflects diverse mechanisms related to heterogeneity of back pain. The extent of association of co-occurring conditions with back pain has implications for clinical management and need for further research to characterize subgroups.

Level of Evidence: 2
Visual Loss Following Spine Surgery
Authors: Shillingford Jamal N. , Laratta Joseph L. , Sarpong Nana O. , Swindell Hasani , Cerpa Meghan , Lehman Ronald A. , Lenke Lawrence G. , Fischer Charla R. 
Published: February 2018

Study Design.
A retrospective review of the Scoliosis Research Society (SRS) morbidity and mortality (M&M) database.

Objective.
The aim of this study was to investigate visual related complications in spinal deformity patients undergoing spine surgery.

Summary of Background Data.
The SRS compiles surgeon-reported complications into an M&M database, tracking postoperative complications including visual loss, neurological deficits, infections, and death. Limited literature exists on postoperative visual complications, a rare but devastating complication following spine surgery.

Methods.
We utilized the SRS M&M database to determine demographics, perioperative risk factors, and prognosis for visual related complications in spinal deformity patients undergoing corrective spine surgery from 2009 to 2012.

Results.
A total of 167,972 spinal deformity patients from 2009 to 2012 were identified with a visual acuity complication (VAC) rate of 0.01%, or 12.5 per 100,000 patients. VAC rates for patients with kyphosis were significantly higher than patients with scoliosis (0.049% vs. 0.010%, P = 0.002) and spondylolisthesis (0.049% vs. 0.005%, P = 0.001). Postoperative visual loss rates significantly decreased from 2010 to 2012 (0.022% vs. 0.004%, P = 0.029). Twenty-one patients identified with VACs had a mean age of 34.8 ± 24.3 years. Two (9.5%) patients had preoperative vision changes, two (9.5%) were diabetic, two (9.5%) had vascular disease, one (4.8%) had a history of thromboembolic disease, and five (23.8%) had hypertension. Extent of VAC was bilateral-partial in four (19.0%), bilateral-total in five (23.8%), unilateral-partial in eight (38.1%), and unilateral-total in three (14.3%) patients. Four (19.0%) patients developed anterior ischemic optic neuropathy, four (19.0%) had posterior ischemic optic neuropathy (PION), five (23.8%) had central retinal artery occlusion, and five (23.8%) developed cortical blindness (CB). Greater than 50% of the VACs occurred on, or before, the first postoperative day. Ten (47.6%) patients recovered complete vision and four (19.0%) improved. All patients with CB and 50% with posterior ischemic optic neuropathy experienced complete resolution.

Conclusion.
VACs occur in approximately 12.5 per 100,000 deformity patients, with a rate five times higher in patients with kyphosis. More than 50% of these complications occur within 24 hours postoperatively. Nearly half of these complications resolve completely, and another 19% improve postoperatively.

Level of Evidence: 4
Postoperative Walking Ability of Non-ambulatory Cervical Myelopathy Patients
Authors: Takeoka Yoshiki , Kaneyama Shuichi , Sumi Masatoshi , Kasahara Koichi , Kanemura Aritetsu , Takabatake Masato , Hirata Hiroaki , Tsubosaka Masanori 
Published: February 2018

Study Design.
A retrospective analysis.

Objective.
The aim of this study was to clarify the postoperative improvement of walking ability and prognostic factors in nonambulatory patients with cervical myelopathy.

Summary of Background Data.
Many researchers have reported the surgical outcome in compressive cervical myelopathy. However, regarding severe gait disturbance,, it has not been clarified yet how much improvement can be expected.

Methods.
One hundred thirty-one nonambulatory patients with cervical myelopathy were treated surgically and followed for an average of 3 years. Walking ability was graded according to the lower-extremity function subscore (L/E subscore) in Japanese Orthopedic Association score. We divided patients based on preoperative L/E subscores: group A, L/E subscore of 1 point (71 patients); and group B, 0 or 0.5 point (60 patients). The postoperative walking ability was graded by L/E subscore: excellent, ≥2 points; good, 1.5 points; fair, 1 point; and poor, 0.5 or 0 points. We compared preoperative and postoperative scores. The cutoff value of disease duration providing excellent improvement was investigated.

Results.
Overall, 50 patients were graded as excellent (38.2%), and 21 patients were graded as good (16.0%). In group B, 17 patients (28.3%) were graded as excellent. Seventeen patients who were graded as excellent had shorter durations of myelopathic symptoms and/or gait disturbance (7.9 and 3.8 months respectively) than the others (29.5 and 8.9 months, respectively) (P < 0.05). Receiver-operating characteristic curve showed that the optimal cutoff values of the duration of myelopathic symptoms and gait disturbance providing excellent improvement were 3 and 2 months, respectively.

Conclusion.
Even if the patients were nonambulatory, 28.3% of them became able to walk without support after operation. If a patient becomes nonambulatory within 3 months from the onset of myelopathy or 2 months from the onset of gait disturbance, surgical treatment should be performed immediately to raise the possibility to improve stable gait.

Level of Evidence: 3
Health-related Quality of Life of Adolescents With Severe Untreated Congenital Kyphosis and Kyphoscoliosis in a Developing Country
Authors: Soliman Hany Abdel Gawwad 
Published: February 2018

Study Design.
A cross-sectional study

Objective.
The aim of this study was to study the health-related quality of life (HRQOL) of adolescents with severe untreated congenital kyphosis (CK) and congenital kyphoscoliosis (CKS) in a developing country.

Summary of Background Data.
Surgical intervention is generally indicated early in patients with progressive CK or CKS to prevent the progression of deformity and to improve the quality of life of the patients. HRQOL of adolescents with untreated CK and CKS in developing countries has never been investigated.

Methods.
Arabic version of the Scoliosis Research Society 22 revision (SRS-22r) questionnaire used to study HRQOL of adolescents with severe untreated CK or CKS in a dev eloping country.

Results.
A total of 134 adolescent (mean age 17.1 years) completed SRS-22r questionnaire: 38 patients with CK from 80° to 110° (group 1), 24 patients with CK > 110° (group 2), 27 patients with CKS (group 3), and 45 healthy controls (group 4). Group 1 had significant lower scores than group 4 in all SRS 22r domains (P < 0.001). Scores of all domains except pain showed significant (P < 0.001) decrease with increase of the severity of CK. Group 3 had significant lower scores than group 2 in all SRS-22r domains except mental health. Satisfaction domain had significant lower scores than all other SRS-22r domains for group 1, 2, and 3. All patients of groups 2 and 3 gave the minimum answers for satisfaction domain questions. A total of 69%, 84% and 94% of group 1, 2, and 3, respectively, gave the minimum answer when asked whether their back condition affects their personal relationships. Female patients of group 1, 2, and 3 had significant lower scores for self-image domain.

Conclusion.
HRQOL is severely affected in adolescents with untreated severe CK and CKS in a developing country.

Level of Evidence: 3
Iliac Crest Bone Graft for Minimally Invasive Transforaminal Lumbar Interbody Fusion
Authors: Haws Brittany E. , Khechen Benjamin , Narain Ankur S. , Hijji Fady Y. , Cardinal Kaitlyn L. , Guntin Jordan A. , Singh Kern 
Published: February 2018

Study Design.
Retrospective Analysis

Objective.
The aim of this study was to determine whether an association between increased acute pain, postoperative time, and direct hospital costs exists between the use of iliac crest bone grafting (ICBG) and bone morphogenic protein (BMP)-2 following a primary, single-level minimally invasive transforaminal lumbar interbody fusion (MIS TLIF).

Summary of Background Data.
ICBG has been associated with enhanced fusion rates. Concerns have been raised in regards to increased operative time and postoperative pain. The advantages of ICBG compared to other spinal fusion adjuncts have been debated.

Methods.
Prospective, consecutive analysis of patients undergoing primary, single-level MIS TLIF with ICBG was compared to a historical cohort of consecutive patients that received BMP-2. Operative characteristics were compared between groups using χ
2 analysis or independent t test for categorical and continuous variables, respectively. Postoperative inpatient pain was measured using the Visual Analog Scale, and inpatient narcotics consumption was quantified as oral morphine equivalents. Outcomes were compared between groups using multivariate regression controlling for preoperative characteristics.

Results.
A total of 98 patients were included in this analysis, 49 in each cohort. No significant differences were noted between cohorts with exception to sex (Females: ICBG, 53.06% vs. BMP-2, 32.65%, P = 0.041). There was a significant increase in operative time (14.53 minutes, P = 0.006) and estimated blood loss (16.64 mL, P = 0.014) in the ICBG cohort. Narcotics consumption was similar between groups on postoperative days 0 and 1. ICBG was associated with decreased total direct costs ($19,315 vs. $21,645, P < 0.001) as compared to BMP-2.

Conclusion.
Patients undergoing MIS TLIF with ICBG experienced increases in operative time and estimated blood loss that were not clinically significant. Furthermore, iliac crest harvesting did not result in an increase in acute pain or narcotics consumption. Further follow-up is necessary to determine the associated arthrodesis rates and long-term outcomes between each cohort.

Level of Evidence: 3