Evaluation of stress and deformation in bone with titanium, CFR-PEEK and zirconia ceramic implants by finite element analysis.

Background: As more recent implant biomaterials, Zirconia ceramic and glass or carbon fibre reinforced PEEK composites have been introduced. In this study, bone stress and deformation caused by titanium, carbon fiber-reinforced polyetheretherketone (CFRPEEK), and zirconia ceramic implants were compared. Materials and Methods: In this in vitro finite element analysis study, a geometric model of mandibular molar replaced with implant supported crown was generated. The study used an implant that was 5 mm diameter and 11.5 length. Three implant assemblies made of CFR- polyetheretherketone (PEEK), zirconium, and titanium were created using finite element analysis (FEM). On the implant's long axis, 150 N loads were applied both vertically and obliquely. ANSYS Workbench 18.0 and finite element software were used to compare the Von Mises stresses and deformation produced with a significance level of P < 0.05. Results: With no discernible differences, all three implant assemblies that is CFR-PEEK, titanium, and zirconia demonstrated similar stresses and deformation in bone. Conclusion: It was determined that zirconia and PEEK and reinforced with carban fibres (CFR-PEEK) can be used as titanium-free implant biomaterial substitutes.

Preoperative imaging of spinopelvic pathologies : State of the art.

The field of musculoskeletal diagnostics and personalized medicine has undergone a revolutionary transformation due to a deeper understanding of skeletal biomechanics and due to technological advancements. Analogous to this transformation, our understanding of spinopelvic conditions has experienced a paradigm shift in terms of both static and dynamic changes in spinopelvic pathologies and enabled a more accurate delineation of the drivers of disability. The purpose of this review is to describe the standard and state of the art of preoperative diagnostic and planning methods for common spinopelvic pathologies and to discuss both the added clinical value and limitations. The rationale is to accelerate the accurate and timely diagnosis and as well as the efficient and safe preoperative workflow.

The association between nationality and nurse job satisfaction in Saudi Arabian hospitals.

BACKGROUND: Job satisfaction is important for increasing nurse retention rates. However, there is little research examining whether there is an association between nationality and job satisfaction among nurses. AIM: To examine whether there is an association between nationality and nurse job satisfaction. METHODS/DESIGN: A cross-sectional survey design was utilized, and 743 nurses from three major government hospitals in Saudi Arabia participated in the survey. Job satisfaction was measured using McCloskey/Mueller Satisfaction Scale. Data were collected between May 2014 and February 2015. RESULTS: Compared with Saudi nurses, expatriate nurses had overall lower job satisfaction after controlling for other predictors. While expatriates were less satisfied than Saudi nurses about extrinsic rewards and family-work balance, however, Saudi nurses were less satisfied than expatriate nurses about their professional opportunities, praise and recognition, and co-worker relationships. CONCLUSION: For some subscales, Saudi nurses were more satisfied than expatriate nurses, while for other subscales, the opposite was true. Nationality should be included in job satisfaction studies in countries with migrant workforces, as nationality-based differences may have been present but masked in earlier international studies by aggregating satisfaction across national groups. IMPLICATIONS FOR NURSING & HEALTH POLICY: Policy makers in Saudi Arabia and other countries with migrant nursing workforces should have effective induction programmes that help newly employed nurses - migrant and local - clearly understand their jobs, roles and responsibilities. Policy makers must have sufficient evidence to modify the reward system to ensure fairness and equality for all.

Correction of the spine with magnetically controlled growing rods in early onset scoliosis : A pre-to-post analysis of 21 patients with 1­year follow-up.

BACKGROUND: Several studies have emphasized that the magnetically controlled growing rod (MCGR) technique decreases complications and costs and could be considered a safe procedure for treating patients with early onset scoliosis (EOS). To the best of our knowledge, the sagittal profile of patients with an implanted MCGR has not been sufficiently studied before. OBJECTIVE: The objectives of this study were twofold: firstly, to evaluate the influence of MCGR on the coronal, sagittal and axial planes. Secondly, to analyze changes of cervical alignment post-MCGR implantation. MATERIAL AND METHODS: This was a retrospective study of patients with EOS who underwent MCGR from 2012 to 2018. Patients were included if they presented with a thoracic or lumbar curvature greater than 40° (Cobb angle) and Risser's sign 0. Global analysis of all patients was reported. Patients were stratified preoperatively by thoracic alignment into a hypokyphotic or kyphotic group. Furthermore, the study population was divided into an anteriorly aligned group and a posteriorly aligned group. Sagittal alignment parameters and parameters of coronal and axial plane were measured and the preoperative to postoperative change was compared then analyzed 1 year after surgery. No external funding was procured for this research and the authors' conflicts of interest are not pertinent to the present work. RESULTS: A total of 21 patients were included in the study. There was a significant coronal correction of the structural and compensatory curves (p < 0.01). Before and after surgery, the coronal C7 plumbline was unchanged and remained within the normal range. Postoperatively, a significant derotation of the apical vertebra in thoracic and lumbar curves was observed (p < 0.05). Global analysis of the sagittal profile revealed a significant decrease of TK (p < 0.001) and T9SPi (p = 0.002) with a simultaneous significant increase of T1T3 angle (p = 0.015) and T1T4 angle (p = 0.015). No significant changes of the sagittal parameters of cervical, lumbar and spinopelvic parameters were noted. Among all groups, cervical parameters did not reveal any statistically significant changes. At 1­year follow up the T1T3 angle (p = 0.01) and T1T4 angle (p = 0.03) were significantly increased. All other measured parameters of sagittal, coronal and axial profile were unchanged. CONCLUSION: The implantation of MCGR had a significant impact on the sagittal profile. Notwithstanding, no further compensatory mechanisms of the cervical spine and pelvis had to be recruited to safeguard sagittal alignment.

[Peak timing for complications after spine surgery]. / Komplikationen im zeitlichen Verlauf nach einer operativen Wirbelsäulenversorgung.

BACKGROUND: Spine surgeries can pose many complications; however, peak timing of post-operative complications in the field of spine surgery is still not sufficiently delineated in the literature as yet. Nevertheless the determination of peak timing of post-operative complications has a significant influence on patient education and post-operative follow-up. MATERIALS AND METHODS: This single-center study analyzed the medical records of 1179 patients that underwent spinal instrumentation between 2010 and 2015 at 3, 6, 12, 24 and 36 months postoperatively. Complications were analyzed according to their time of onset. RESULTS: Of the 1179 patients included, 199 (16.9%) underwent revision surgery due to a complication. Peak timing for complications (72.9%) occurred within the first 3 months after surgery. Infection was the most common reason for revision surgery (42.7%) and most infections occurred within the first 3 months after surgery (early infections) (91.8% of infections). Peak timing for material failure occurred in the second post-operative year (46% of all detected prosthesis failures) (2.5% of all complications). DISCUSSION: Peak timing of post-operative complications post spinal instrumentation occurs as early on as within the first 3 months after surgery and post-operative infections remain the most common post-operative complication overall. Nonetheless, regular and long-term postoperative clinical and radiological follow-up is crucial, since in particular prosthesis failure has its peak timing in the second post-operative year.

Interrater reliability of three-dimensional reconstruction of the spine : Low-dose stereoradiography for evaluating bracing in adolescent idiopathic scoliosis.

BACKGROUND: Bracing constitutes the mainstay treatment for mild scoliosis. The 3D reconstruction of the spine using low-dose stereoradiographic imaging (LSI) is increasingly being used to determine the true shape of the deformity and to assess the success of bracing. OBJECTIVE: The aim of the study was to validate the measurement of 3D spinopelvic parameters and vertebral rotation in the setting of bracing treatment via a reliability study conducted in adherence to the guidelines for reporting reliability and agreement studies (GRRAS). MATERIAL AND METHODS: Full spine stereoradiographs of patients with adolescent idiopathic scoliosis (AIS) who underwent Chêneau bracing were retrospectively analyzed. The 3D reconstruction was performed by two experienced operators in a blinded manner and randomized order. Rotation of every vertebra was computed in the coronal, sagittal and axial planes. Sagittal spinopelvic parameters were evaluated. All measurements were statistically compared to determine agreement of the measurement of brace correction using the intraclass correlation coefficient (ICC). RESULTS: In this study, 45 patients (81% females) aged 12.5 ± 2 years were included. The mean absolute difference was less than 3.5° for all measured angles, less than 4 mm for sagittal vertical axis (SVA) and less than 1.5 mm for lateral pelvic shift. The ICC was high for all parameters (ICC >0.81). Despite the overall high reliability, the reliability of axial rotation was lower in the upper and middle thoracic spine and the lower lumbar spine. CONCLUSION: Brace wearing during full spine LSI acquisition does not affect spinal measurements. The LSI under bracing treatment produces reliable measurements of spinopelvic parameters as well as vertebral rotation. These reproducible 3D data enable spine surgeons to assess the true shape of the deformity, to quantify rotation of each vertebra and enhance the understanding of the efficacy of bracing treatment.

Pyogenic spondylodiscitis : The quest towards a clinical-radiological classification.

BACKGROUND: Pyogenic spondylodiscitis (PS) is a debilitating condition laden with orthopedic and neurological complications. The choice of the best step in management is often delayed due to the controversy encompassing its multiple facets. Several classification systems were proposed in the literature to define optimal management; however, consensus was not achieved. OBJECTIVE: The aim of this study was to review the literature and critically appraise the classification systems of PS and the rationale behind the classification criteria. METHODS: A literature search was conducted in PubMed. Titles and abstracts of articles were searched using different synonyms of spondylodiscitis and its classification. No restrictions regarding language of publication or date of publication were applied. RESULTS: A total of 43 papers with 5 encompassing 3 main classifications were found in the literature. These classifications were overlapping but different. They encompassed neurologic deficits, abscess formation and segmental instability, laboratory parameters and morphological changes in magnetic resonance imaging (MRI) as the most important factors used to classify PS, assess the severity and guide treatment. CONCLUSION: The current classification schemes overlap and encompass the most clinically relevant factors; however, some could be too complex for interdisciplinary clinical practice and do not adequately address unique entities, such as PS of the cervical spine, anterolisthesis and retrolisthesis. Most importantly, some criteria must be utilized in concert with recently published guidelines and should be re-assessed for validity and reliability. A uniform orthopedic parlance is required to optimize the management of this debilitating and life-threatening condition.

Nonmetallic posterior monosegmental cervical fusion of a dislocated C6/7 fracture in a 4-year-old girl : A case report.

PURPOSE: Pediatric cervical spine injuries constitute approximately 1-2% of all pediatric trauma cases. Usually pediatric vertebral injuries appear as stable A type fractures, whereas B and C type injuries are relatively uncommon. In contrast to adults, the appropriate treatment strategy in children is still controversial and places spine surgeons in complex situations. This article reports the case of a 4-year-old girl with an unstable B type injury at the C6/7 level (AOSpine C6-7: B2 [F4 BL, C7:A1]) with bilateral locked fractures of the facet joints after falling down a flight of stairs. PATIENT AND METHODS: Magnetic resonance imaging (MRI) and computed tomography (CT) were initially performed. The 4­year-old girl was treated under intraoperative neurophysiological monitoring via open reduction after partial resection of both C7 upper articular processes and nonmetallic monosegmental posterior interlaminar fusion (FiberWire®) at the C6/7 level with temporary immobilization in a halo brace. RESULTS: Clinical and radiological follow-up was carried out after 9 months. The patient suffered no pain or neurological deficits. Plain radiographs revealed a correct cervical alignment with anatomical correction of the initial dislocation. CONCLUSION: The treatment of highly unstable pediatric B type injuries of the lower cervical spine via open reduction and nonmetallic monosegmental posterior interlaminar fusion results in good clinical and radiological outcomes. A temporary immobilization in a halo brace provides stability until osseous fusion occurs.

Cervical spine alignment following surgery for adolescent idiopathic scoliosis (AIS): a pre-to-post analysis of 81 patients.

BACKGROUND: Several studies have emphasized the importance of restoring thoracic kyphosis (TK) in the setting of AIS, but very few have discussed changes in cervical spine alignment following surgery. Aim of this study was to evaluate reciprocal cervical alignment change after modification of global and regional thoracolumbar alignment with surgery in the setting of adolescent idiopathic scoliosis (AIS). METHODS: Baseline and 2-yrs follow-up radiographs of AIS patients (n = 81) were analysed measuring cervical parameters (upper cervical: C2-C0, McGregor Slope; lower cervical: C2-C7, C2-C7 sagittal vertical axis (SVA), C2-T3, C2-T3SVA, C2-T1Harrison (C2-T1Ha), T1 Slope (T1S)), thoracic, lumbar, pelvic and global alignment parameters. Post-operatively, patients were grouped twice; based on changes in TK and SVA. Cervical alignment was compared between groups. Pearson correlation was conducted to examine the relationship between changes in TK, SVA, and cervical alignment. RESULTS: Stratification by change in TK, revealed significant alteration of lower cervical alignment T1S [p < 0.001]), C2-T3 [p = 0.019], C2-T1Ha [p = 0.043]), but there was no reciprocal change in the upper cervical spine. Stratification by SVA revealed a significant coexisting change in the lower cervical spine (T1S [p < 0.001], C2-C7SVA [p = 0.034], C2-T3 [p = 0.023], C2-T3SVA [p = 0.001]). SVA change was not associated to a change in the upper cervical spine. The correlation analysis showed that with a post-operative increase in TK, the cervical spine became more lordotic. Changes in TK were significantly correlated with: ΔT1S, ΔC2-C7, ΔC2-T3, and ΔC2-T3SVA. Similarly, increased cervical kyphosis was found when SVA was decreased post-operatively. Furthermore, there was a significant correlation between change of SVA and both ΔC2-T3 and ΔC2-T3SVA. CONCLUSIONS: In surgically treated AIS patients, changes in global and regional alignment of the thoracolumbar and cervical spinal segments exhibit interdependence. Thus, surgical planning with regard to sagittal deformity in AIS patients should account for the post-operative impact on cervical alignment.

Erratum to: Magnetically controlled growing rods for rigid scoliosis : An alternative to halo-gravity traction in preparing for definitive correction?

Erratum to: Orthopäde 2018 https://doi.org/10.1007/s00132-018-3631-7 Dear Reader,Unfortunately, an incorrect subtitle was published in the online version of the article.We kindly ask you to use the correct title:"Magnetically controlled growing rods for rigid scoliosis.An alternative to halo-gravity ….

Magnetically controlled growing rods for rigid scoliosis : An alternative to halo-gravity traction in preparing for definitive correction?

The treatment concept for severe rigid idiopathic scoliosis is a short-term application of halo-gravity traction to enable maximum correction and subsequent dorsal fusion. The method has already been mentioned in the literature as an effective procedure. This case report demonstrates the use of a new treatment concept using magnetically controlled distraction rods as a possible alternative to the halo-gravity traction device. To our knowledge the use of this technique in severe rigid idiopathic scoliosis has not yet been published.

[Normal sagittal profile of the cervical spine - must the cervical spine always be lordotic?] / Das normale sagittale Profil der Halswirbelsäule ­ muss die Halswirbelsäule immer lordotisch sein?

BACKGROUND: The cervical spine is very complex, and it allows the largest range of motion relative to the rest of the spine. The fundamental function of the cervical spine is to maintain the head balanced over the trunk and to maintain horizontal gaze. The cervical spine must be both stable and flexible to guarantee function. Changes of the sagittal profile of the cervical spine may affect function and quality of life. The relationship between full body alignment and maintaining gaze necessitates a thorough understanding of the cranio-spino-pelvic alignment as a component of balance. QUESTION: Now the question is, what kind of sagittal profile does the cervical spine need for proper function? In the literature, normal sagittal alignment of the cervical spine is controversial. In general, there is the assumption that the alignment is lordotic. Does the data in the literature support this? RESULTS: The present literature review supports the following facts: Ideal cervical spine alignment is mostly lordotic, but not always; ideal cervical spine alignment can be lordotic, neutral or kyphotic; ideal cervical spine alignment is driven by the necessity of supporting the head and maintaining horizontal gaze; the cervical spine is in harmony with regional alignment (thoracic kyphosis) and sagittal global alignment (SVA): TK (↑) → T1 Slope (↑) → CL (↑), TK (↓) → T1 Slope (↓) → CL (↓), SVA >50 mm: the cervical curve should be lordotic to maintain horizontal gaze, SVA <0 mm: the cervical curve should be kyphotic to maintain horizontal gaze.

[Spondylotic cervical myelopathy : Indication of surgical treatment]. / Die zervikale spondylotische Myelopathie : Indikationsstellung für eine chirurgische Therapie.

BACKGROUND: The pathogenesis of cervical spondylotic myelopathy (CSM) is often multifactorial. Hence, the treatment of this disease requires a differentiated surgical approach in order to adequately address the underlying pathology. PURPOSE: The aim of this review is to identify factors that influence the choice of treatment strategy and to summarize them in an algorithm that serves as a decision aid in choosing the optimal indication for surgical treatment. An attempt is made to define the threshold values for the indication of surgical treatment and to discuss the ideal timing for performing surgery. MATERIALS AND METHODS: On the basis of the published data, the influencing factors on the prognosis of CSM, as well as surgical approaches are discussed. RESULTS: Circumferential spinal cord compression, a sharply defined myelopathy signal in the T2-weighted MRI sequence, and segmental instability at the level of the myelopathy signal mean an unfavorable prognosis for the worsening of CSM. The most important factors that influence the choice of the surgical access point are the sagittal profile of the cervical spine, the extent of myelopathy, the extent of stenosis, and the location of the myelopathy-inducing pathology. Previously existing neck pain and prior cervical surgery must also be considered. DISCUSSION: On the basis of the research carried out, we developed an algorithm that could serve as an aid in choosing the right treatment in the setting of cervical spondylotic myelopathy.

[A new classification of surgical complications in adult spinal deformity]. / Eine neue Komplikationsklassifikation in der adulten spinalen Deformitätenchirurgie.

BACKGROUND: In the light of the increasingly aging population and the widespread understanding of the sagittal profile of symptomatic patients with adult spinal deformity (ASD), pervasive utilization of osteotomies on the vertebral column should be expected. These surgeries are accompanied with relatively high complication rates. However, there is no uniform definition or classification in terms of grading the severity or chronological incidence of complications after ASD surgery. OBJECTIVES: The aim of this work is to give an overview of the different classifications described in the literature hitherto and to propose a standardized, clinically utile classification of complications after ASD surgery. Finally, the aim is to illustrate this classification using two case examples. MATERIALS AND METHODS: We conducted a systematic PubMed search with the keywords: "adult spinal deformity", "surgery", "complications" and "classification". Results were screened by title, abstract and full-text article. RESULTS: 22 articles were included in this review. Regarding the systematic classification of the severity of a complication, the CTCAE classification (Common Terminology Criteria for Adverse Events v4.0) is a validated and well-established severity stratification tool used in oncologic treatment. Regarding chronological occurrence, complications can be categorized into three phases: intra-operative, peri-operative and post-operative. DISCUSSION: The time of occurrence of a certain complication and its severity should constitute the cornerstones of a standardized and practical classification of complications after ASD surgery. To enable uniform reporting and coherent documentation of complications, spine surgeons should find consensus on a standardized classification. Future work needs to be directed towards defining and conducting an individual pre-operative risk stratification of adult spine deformity surgical candidates leading to a possible mitigation of surgery-related complications.

[Metastatic breast cancer in the spine : Molecular predictors for choosing adequate treatment strategies]. / Spinale Mammakarzinommetastasen aus Sicht der Wirbelsäulenchirurgie : Prädiktoren auf Molekularebene zur Wahl der adäquaten Therapiestrategie.

Breast cancer is the most common malignancy affecting women and the spinal column is most likely affected by metastases. Modern oncologic treatment options have significantly prolonged survival times in the last decade. Therefore, treatment of vertebral metastases has been of special interest in spine surgery. Different scores are described to evaluate prognosis and to choose correct treatment strategies, which however only differentiate tumor entities and not specific tumor phenotypes. Breast cancer has been classified into five intrinsic subtypes with different survival rates since the turn of the millennium. The aim of this review was to describe molecular predictors of breast cancer malignancy and to better estimate expected survival times and invasiveness of therapies with regard to spinal metastases.

[Risk factors for the development of rotator cuff tears in individuals with paraplegia : A cross-sectional study]. / Risikofaktoren für Rotatorenmanschettenrupturen bei Paraplegikern : Eine Querschnittstudie.

QUESTION: Shoulder pain and rotator cuff tears are highly prevalent among wheelchair dependent individuals with paraplegia. The purpose of this study was to identify potential risk factors associated with the development of rotator cuff tears in this population. METHODS: A total of 217 wheelchair dependent individuals with paraplegia were included in this cross-sectional study (level of evidence III). The mean age of this population was 47.9 years and the mean duration of wheelchair dependence was 24.1 years. Each individual was asked to complete a questionnaire designed to identify risk factors for rotator cuff tears and underwent a standardized clinical examination with the documentation of the Constant-Murley shoulder outcome score and magnetic resonance imaging (MRI) of both shoulder joints. RESULTS: MRI analysis revealed at least one rotator cuff tear in 93 patients (43%). Multiple logistic regression analysis identified the following factors to be associated with the presence of rotator cuff tear: patient age, duration of spinal cord injury/wheelchair dependence, gender, and wheelchair athletic activity. Neither BMI nor the level of spinal cord injury was found to pose a risk factor in the population studied. With respect to patient age, the risk of developing a rotator cuff tear increased by 11% per annum. In terms of duration of spinal cord injury, the analysis revealed a 6% increased risk per year of wheelchair dependence (OR = 1.06). Females had a 2.6-fold higher risk of developing rotator cuff tears than males and wheelchair sport activity increased the risk 2.3-fold. DISCUSSION: There is a high prevalence of rotator cuff tears in wheel-chair dependent persons with paraplegia. Risk factors such as age, gender, duration of paraplegia, and wheel chair sport activity seem to play an important role in the development of rotator cuff tears.

[What is actually adult spinal deformity? : Development, classification, and indications for surgical treatment]. / Was ist eigentlich eine adulte spinale Deformität? : Entwicklung, Klassifikation und Indikation zur operativen Therapie.

BACKGROUND: Adult spinal deformity (ASD) is a complex entity that has had emerging significance for spine surgeons in the last decade. Sagittal and/or coronary deformities can have a high impact (disability, pain) on the quality of patients' life. Radiologic diagnostics determine the common spinopelvic parameters as the basis for classification of ASD. TREATMENT: Conservative treatment options may be sufficient in mild cases. The deformity's complexity frequently demands the entire spectrum of methods and techniques in spinal surgery. This article gives an overview on the development of the ASD, the correct classification as well as the indication for surgical therapy.

Prevalence of upper extremity pain in a population of people with paraplegia.

STUDY DESIGN: Cross-sectional study. OBJECTIVES: To determine the prevalence, patterns, and predictors of musculoskeletal pain in the upper extremity joints among wheelchair-dependent individuals with post-traumatic paraplegia. Secondarily, to document most common reported causes of upper extremity pain. SETTING: Centre for Orthopaedics, Trauma Surgery and Spinal Cord Injury, Germany. METHODS: The study was done by means of a structured questionnaire, which was mailed to the individuals who had been treated between 1990 and 2007 for newly sustained or pre-existing, accident-related paraplegia (n = 670). The questionnaire was designed mainly to obtain the information regarding shoulder, elbow, and wrist pain. Additional data included participant demographics, mechanism, level and completeness of injury as well as wheelchair dependence and time since injury. The Frankel classification system was used to define the completeness of injury. RESULTS: Four hundred and fifty-one (67%) questionnaires were included. Pain was reported by approximately 81% of the participants. Of this sample, 61% had shoulder pain, 33% had elbow pain, and 43% had wrist pain, 19% had shoulder, elbow, and wrist pain, 27% had shoulder and elbow pain, 34% had shoulder and wrist pain, 21% had elbow and wrist pain. The main diagnoses were rotator cuff tears for individuals with shoulder pain, epicondylitis for those with elbow pain, and carpal tunnel syndrome for those with wrist pain. The development of shoulder/elbow and wrist pain correlated with age and time since injury. CONCLUSIONS: Age and the length of time since injury correlated with a higher rate of shoulder, elbow, and wrist pain. The completeness of injury, neurological level, and gender were correlated with shoulder, elbow, and wrist pain, respectively.