Construction Of Instrument Research Articles

A Biomechanical Analysis of Instrumentation Constructs During Vertebral Column Resection: Stability When You Need It!

Biomechanical Testing. Investigate the optimal construct for stabilization of the spine during vertebral column resection (VCR). VCR is a powerful technique for achieving correction in severe cases of spinal deformity. However, this also creates an unstable spine which requires stable fixation to prevent iatrogenic neurologic injury. It is common practice to place a temporary unilateral rod configuration to achieve this stability during surgery but no study to date has investigated the optimal construct configuration. A unilateral VCR model representing an acute 50° kyphotic deformity with a standardized 30mm resection was created. Three conditions underwent testing: 1) Rod material and diameter, 2) rod configuration, and 3) number of fixation points. Six unique samples were tested in each group in both flexion-extension. Prior to testing a 10N preload and underwent cyclical testing in flexion/extension. System stiffness was calculated and compared across groups. Assessment of rod size and composition using a single screw construct (2 total screws) demonstrated that for Titanium (Ti) rods, increasing rod size significantly increased the construct stiffness (P=0.001). Although Cobalt-chromium (Co-Cr) rods where significantly stiffer than the corresponding sized Ti rods, there was no significant difference between rod diameters for Co-Cr (P=0.98). However, when tested using a dual screw (4 total screws) construct, these constructs were significantly stiffer than the corresponding single screw constructs (P<0.0001). Of the various rod configurations, the dual rod demonstrated the greatest stiffness (34.8±2.1N/mm; P<0.0001). Surgical construct stiffness during a VCR is multifactorial. Larger rod diameter, increased number of fixation points, stiffer rod material, and increased number of rods across the resection site increase the construct stiffness. With minimal points of fixation using Co-Cr rods, increasing rod diameter does not impart greater construct stiffness unless additional fixation points are included.

Authentic Assessment Instrument on Redox Reactions to Assess Students’ Cognitive Skills

Authentic assessment is an assessment approach that enable students to demonstrate in-depth understanding and solve complex problem using systematic thinking skills, but teachers find it difficult to develop due to limited knowledge and time. The aim of this research is to produce an authentic assessment instrument for redox reaction materials; determine the characteristics, quality, and feasibility. The instrument development model used was a combination of Oriondo &amp; Dallo-Antonio with Cohen Swerdlik. The development stages were assessment planning, instrument construction, and product testing. The research subjects were 155 of 10th-grade students from three public high schools in Bukittinggi, selected using random sampling technique. Data collection techniques were tests and non-test, the instruments were open ended questions and validation sheets. The authentic assessment instrument developed criteria are: (1) can assess students’ higher order thinking skills; (2) integrate knowledge with skills and various scientific disciplines; (3) develop 21st century competencies; and (4) involve real or everyday life contexts for cognitive aspect. The trial results were analyzed using the PCM 1-PL approach at IRT using Winstep and Parscale program. The characteristics of the item were stated fit because it met the acceptance requirements for MNSQ, ZSTD, and PT-Measure Correlation and the difficulty is in a relatively good level. The reliability of the instrument was classified as good, with test reliability of 0.72 and item reliability of 0.96.

Los instrumentos integradores en los sistemas de cuidados en América Latina: una visión de política pública

Some Latin American governments have developed systems that seek to comprehensively guarantee the right to provide and receive care. These initiatives aim to recognize, redistribute, or reduce caregiving work within households by coordinating a set of policies, implemented by different agencies, around the same individual. Achieving this requires overcoming the challenge of intersectoral coordination, based on management instruments that allow interventions to be articulated around the diverse care needs of the population. Based on the policy integration literature, we conduct a comparative analysis of four emblematic care systems in the region using official data and semi structured interviews. In contrast to recent research that analyzes programs, services, and target populations, we focus on how systems manage to operate in a coordinated manner. We argue that building care systems requires the construction of instruments that ensure the integrated operation of the system around a person or territory. We examine how the deployment of specific decisions to guide the operation of care systems address a key contemporary challenge in public policy and administration: the coordinated operation of policy sectors around complex problems and the construction of comprehensive responses to multidimensional challenges.

Surgical management of thoracolumbar burst fractures by three different posterior techniques: A prospective comparative study

Study designProspective Comparative Study. ObjectivesThis study aims to study the outcome of thoracolumbar burst fractures by comparison of 3 different posterior constructs groups of patients treated by the posterior approach. SettingUniversity level Tertiary care Centre of Northern India. MethodsSingle centre study conducted from September 2020 to April 2022, the study included patients aged 18–50 years with burst fractures in the thoracolumbar region, TLICS score ≥4, and injury surgery duration <3 weeks. Sixty patients were divided into three groups: Group I (short segment with index screw(s) in the fractured vertebrae), Group II (short segment with interbody cage fusion), and Group III (long segment without index screw or interbody cage). Clinical and radiological assessments were performed over a 6-month follow-up period. Outcome measures included the Visual Analog Scale (VAS) for pain, Oswestry Disability Index (ODI), American Spinal Injury Association (ASIA) impairment scale, and radiological parameters. ResultsAmong 60 patients, 38 were male, and 22 were female, with a mean age of 33.37 ± 12.26 years. The most common injury mechanisms were falls from heights (85 %). Group I had the lowest estimated blood loss (395 ± 36.20 ml) and shortest surgery duration (140 ± 26.56 min), while Group III had the highest blood loss (744.25 ± 113.69 ml) and longest surgery duration (203.50 ± 23.40 min). No statistically significant differences were observed in kyphosis correction, canal clearance, or fusion status among the groups. Neurological and functional outcomes improved across all groups, with no significant intergroup differences. ConclusionAll three posterior instrumentation constructs provided effective management of thoracolumbar burst fractures, demonstrating high rates of fusion, significant kyphosis correction, and minimal loss of alignment. Despite variations in surgical parameters such as estimated blood loss and surgery duration, the clinical and radiological outcomes were comparable. Level of evidenceIII.

Constructing a measure for self-perceived open organizational culture in a university hospital pharmacy.

An open organizational culture in the workplace represents an environment where information, ideas, and feedback are freely exchanged among all members, regardless of position or rank. Currently, there are no valid survey instruments to measure this culture within a healthcare context. To address this gap, we developed a survey instrument to measure self-perceived open organizational culture at a university pharmacy using a test re-test study design. Data were collected during classroom training on basic mediation skills study. Participants completed the same questionnaire before (test phase) and after the training (validation phase). The questionnaire included statements assessing open organizational culture. The data were analyzed using standardized psychometric methods, including correlations, Exploratory Factor Analysis (structural validity), and construct validity by correlating the open organizational culture scores with the Interpersonal Communication Inventory. In the test phase, 191 participants (161 females, 84%; response rate = 39.7%) contributed to the initial construction of the self-perceived open organizational culture survey instrument. In the validation phase, 81 of the original respondents completed the questionnaire again. Three latent factors were identified, retaining 22 of the 37 items: "enabling systems" (7 items), "open behavior" (8 items), and "trusting and supporting coworkers" (7 items). High correlations were found among the three factors (r > 0.6), and between these factors and the Interpersonal Communication Inventory (r > 0.35). Cronbach's alphas were all above 0.85, indicating good internal consistency. During the validation phase, the factors demonstrated high internal consistency, test/re-test correlations, and agreement. This study presents a 22-item survey instrument for measuring individual differences in self-perceived open organizational culture within a university hospital pharmacy. The instrument demonstrates internal consistency and construct validity. Further validation of its psychometric properties and testing in other healthcare departments are recommended.

Development and validation of Parents’ Health Literacy Scale on Preventing Road Traffic Injuries for children aged 0–6 years in China

BackgroundRoad traffic injuries are the leading cause of death in children. Parents’ health literacy (HL) is closely related to child safety, especially for the young children. This study aimed to...

Relationships between self-efficacy beliefs and personal factors in final-year medical students

BackgroundMedical students entering postgraduate training often feel ill-prepared for clinical practice. This has implications for physician well-being and the quality of patient care. Self-efficacy represents an important contributing factor in the transition process. Identifying student characteristics associated with self-efficacy is important in order to design possible interventions to enhance self-efficacy. Therefore, we assessed the relationship between final-year medical students’ general self-efficacy with their personality traits, need for cognitive closure, and medical knowledge in order to identify factors contributing to the assessment and improvement of self-efficacy.MethodsSelf-assessed data regarding general self-efficacy was collected from 188 final-year medical students who participated in a first day of residency simulation between March and September 2023. We also assessed several personal factors including the HEXACO Personality Inventory Revised (HEXACO-PI-R), a short scale to measure Need for Cognitive Closure (16-NCCS), and students’ medical exam grades (M2). We ran multiple correlation and multiple linear regression analyses across all variables. We then added a second analysis each with general self-efficacy and HEXACO domains Emotionality and Extraversion on facet level, which both showed significant associations with self-efficacy in the respective first analysis.ResultsAcross all variables, self-efficacy correlated significantly negatively with Emotionality and positively with Extraversion. Both domains also significantly predicted self-efficacy accordingly in the regression model. On a facet analysis, Sentimentality (Emotionality) and Sociability (Extraversion) did not correlate significantly with self-efficacy. In the regression model only the facets Sociability (Extraversion) and Fearfulness (Emotionality) significantly predicted lower self-efficacy. Furthermore, self-efficacy correlated significantly and negatively with the Need for Cognitive Closure (NCC). Additionally, significant positive and negative correlations of the NCC with both Emotionality and Extraversion, respectively, as well as a significant positive correlation for exam grades (M2) and Extraversion were found.ConclusionsSelf-efficacy contributes to medial students’ preparedness for clinical practice and can be predicted by several personal factors. Students should learn and reflect about these factors and need to be supported in increasing their self-efficacy and its self-assessment towards their transition to postgraduate training. Construction of a specific instrument for self-efficacy assessment utilizing the insight provided by the findings is proposed as a next step.

Development and construction of a cost-effective non-contact instrument for measuring the dielectric constant of liquids.

This research presents the development and construction of a cost-effective instrument, designed to measure the dielectric constant of liquids by employing a non-contact method that relies on determining the capacitance of a cell containing the liquid and its relaxation frequency. This instrument utilizes an astable multi-vibrator integrated with a resistance-capacitor network, in which the cell housing the liquid of interest functions as a capacitor element of the oscillator. The frequency of the generated oscillations is meticulously recorded using a seven-digit frequency meter with a resolution of 1Hz. The cell was filled with an array of pure liquids with known dielectric constants, and their frequencies were subsequently recorded at ambient temperatures. An equation was fitted to the frequency-dielectric constant curve, which was used as a calibration equation to determine the dielectric constant of subsequent liquids. In addition to pure liquids, dielectric constants for solvent mixtures of varying mole fractions were also calculated using the previously established calibration equation. Our results demonstrated excellent frequency stability of the instrument, and the obtained dielectric constant values displayed significant consistency with both the experimental data and predictions made by computational methodologies. This suggests that the constructed instrument exhibits a high level of accuracy in measuring the dielectric constant of both pure and mixed liquids, establishing its potential utility in relevant research and industrial applications.

Instrument Construction and Exploration of Students' CollaborationSkillsBased on the Summated Rating Scale

One of the essential 21st-century skills that students must possess is the ability tocollaborate. However, profiling students' collaboration skills is challengingwithout valid and reliable instruments. Therefore, this research aims to map the profile of students' collaboration skills using valid and reliable instruments. This study is descriptive-explorative research with a quantitative approach. The research sample included 900 Islamic Senior High School/Madrasah Aliyahstudents, with 150 students participating in the instrument trials and 750 servingas the primary sample in this study. The results indicate that the collaborationability instrument is valid and reliable, as demonstrated by a loading factor value &gt; 0.5, T-Value &gt; 1.96, RMSEA 0.00 &lt; 0.08, RMR 0.043, Std. RMR0.040, GFI 0.95, AGFI 0.87, NNFI 0.97, CFI 0.98, IFI 0.98, RFI 0.97, PNFI 0.85, and a composite reliability coefficient CR=0.909 from the second-order confirmatoryfactor analysis. The findings show that students' collaboration skills are moderate, with an average score of 26.4, which falls within the medium category. The distribution of students' abilities is as follows: 347 students (46.3%) are classifiedas having moderate abilities, 207 students (27.6%) as having high skills, and 196students (26.1%) as having low skills. Based on these results, teachers andstakeholders are encouraged to enhance students' collaboration skills throughstudent-centred learning approaches, such as project-based learning, which canprovide students with opportunities to engage and practice working together actively in the learning process.

Multirod posterior occipitocervical instrumentation constructs: a biomechanical analysis and initial case series of 10 patients with complex craniocervical pathology

BACKGROUND CONTEXTStabilization of the occipitocervical (OC) junction with posterior instrumentation plays a vital role in addressing a spectrum of pathologies. Due to limited bone surfaces of the occiput and C1 lamina, achieving union across the OC junction is challenging. PURPOSETo explore the biomechanics and a clinical series of patients treated with multirod constructs across the OC junction using a novel occipital plate with single- and dual-headed, modular tulip heads. STUDY DESIGN/SETTINGBiomechanical analysis and retrospective case series. PATIENT SAMPLEAdults at a single institution who underwent posterior cervical multirod constructs across the OC junction. OUTCOME MEASURESOC–C4 range of motion (ROM), maximum von Mises stress on the rods, and adjacent segment ROMs and intradiscal parameters. Patient demographics, revision operations, rod breakages, wound complications. METHODSA validated occiput-cervical finite element (FE) model was used to simulate OC–C4 cervical fixation under multidirectional pure moment loading. A total of 4 rod configurations were simulated: (A) 2-rod-Ti (4.0 mm titanium rods); (B) 2-rod-CoCr (3.5 mm cobalt chrome rods); (C) 3-rods (4.0 mm titanium rods); (D) 4-rods (4.0 mm titanium rods). The aforementioned measures were compared. A retrospective analysis was also performed of adults at a single institution who underwent posterior cervical multirod constructs across the OC junction. RESULTSBiomechanically, lowest primary rod stresses were observed for 3- and 4-rod constructs. Compared to 2-rod-Ti (121.8 MPa), 2-rod-CoCr showed a 43.2% stress increase in the rods, while 3- and 4-rods experienced rod stress reductions of 20% and 23.2%, respectively. No appreciable differences in OC–C4 ROM, C4–5 ROM, and C4–5 discal stresses were found between multirod and 2-rod constructs. Maximum occipital and C4 screw stresses were decreased in multirod constructs compared to 2-rods, with least stresses noted in the 4-rod construct. Maximum plate stresses were slightly increased in the 4-rod construct compared to 2- and 3-rod fixation, though the forces were largely similar among the constructs. Ten patients (average age 66.4±10.6 years; 8 males) were assessed clinically. Nine of the ten operations were for primary stabilization of pathological fractures and associated craniocervical and/or atlantoaxial instability using 4-rods across the OC junction. At an average follow-up time of 1.58±0.5 years (range, 1–2.3 years), there were no instrumentation failures, no adjacent segment failures, and no wound complications. CONCLUSIONSIn this proof-of-concept investigation, multiple rods (3- and 4-rods) across the OC junction using a novel occipital plate with single- and dual-headed, modular tulips was safe and effective in stabilizing the OC junction. Accompanying FE analysis demonstrated that multirod constructs decreased primary rod stresses and had lower stresses on occipital and C4 screws compared to 2-rod constructs, while occipital plate stresses were largely similar. Additional clinical studies are needed to confirm these findings and to determine the ultimate utility of multirod constructs across the OC junction.

The validity and reliability of research needs analysis instrument (RISK model) in administering needs items and research

This study aims to design a Research Needs Analysis Instrument (RISK Model) to guide researchers in obtaining expert confirmation of research needs or problem statements before implementation. Library research was conducted, applying Kolb’s theory (1984) and Maslow’s Hierarchy of Needs (Maslow, 1943) to inform the instrument’s constructs. The instrument consists of four main constructs: Relevance, Importance, Strategy, and Knowledge, which serve as pillars in administering items for problem statements or research issues. The Content Validity Index (CVI) values for the instrument constructs, as assessed by six expert panels, were found to be 0.90 for Relevance, 0.90 for Importance, 0.88 for Strategy, and 0.90 for Knowledge, with an average mean of 0.90, indicating high adoptability. The Cronbach’s alpha reliability values (α) based on pilot study results (n:30) ranged from 0.87 to 0.90, including 0.92 for content, 0.87 for understanding, 0.90 for clarity, 0.88 for relevance, and 0.90 for ease of use. These findings demonstrate that the Research Needs Analysis Instrument (RISK Model) achieves a high level of reliability. Overall, the instrument is a standard guide for researchers to obtain expert confirmation of research needs or problems before conducting a study.

Evaluating the Construct Validity of the Charité Alarm Fatigue Questionnaire using Confirmatory Factor Analysis.

The Charité Alarm Fatigue Questionnaire (CAFQa) is a 9-item questionnaire that aims to standardize how alarm fatigue in nurses and physicians is measured. We previously hypothesized that it has 2 correlated scales, one on the psychosomatic effects of alarm fatigue and the other on staff's coping strategies in working with alarms. We aimed to validate the hypothesized structure of the CAFQa and thus underpin the instrument's construct validity. We conducted 2 independent studies with nurses and physicians from intensive care units in Germany (study 1: n=265; study 2: n=1212). Responses to the questionnaire were analyzed using confirmatory factor analysis with the unweighted least-squares algorithm based on polychoric covariances. Convergent validity was assessed by participants' estimation of their own alarm fatigue and exposure to false alarms as a percentage. In both studies, the χ2 test reached statistical significance (study 1: χ226=44.9; P=.01; study 2: χ226=92.4; P<.001). Other fit indices suggested a good model fit (in both studies: root mean square error of approximation <0.05, standardized root mean squared residual <0.08, relative noncentrality index >0.95, Tucker-Lewis index >0.95, and comparative fit index >0.995). Participants' mean scores correlated moderately with self-reported alarm fatigue (study 1: r=0.45; study 2: r=0.53) and weakly with self-perceived exposure to false alarms (study 1: r=0.3; study 2: r=0.33). The questionnaire measures the construct of alarm fatigue as proposed in our previous study. Researchers and clinicians can rely on the CAFQa to measure the alarm fatigue of nurses and physicians.

Musician-AI partnership mediated by emotionally-aware smart musical instruments

The integration of emotion recognition capabilities within musical instruments can spur the emergence of novel art formats and services for musicians. This paper proposes the concept of emotionally-aware smart musical instruments, a class of musical devices embedding an artificial intelligence agent able to recognize the emotion contained in the musical signal. This spurs the emergence of novel services for musicians. Two prototypes of emotionally-aware smart piano and smart electric guitar were created, which embedded a recognition method for happiness, sadness, relaxation, aggressiveness and combination thereof. A user study, conducted with eleven pianists and eleven electric guitarists, revealed the strengths and limitations of the developed technology. On average musicians appreciated the proposed concept, who found its value in various musical activities. Most of participants tended to justify the system with respect to erroneous or partially erroneous classifications of the emotions they expressed, reporting to understand the reasons why a given output was produced. Some participants even seemed to trust more the system than their own judgments. Conversely, other participants requested to improve the accuracy, reliability and explainability of the system in order to achieve a higher degree of partnership with it. Our results suggest that, while desirable, perfect prediction of the intended emotion is not an absolute requirement for music emotion recognition to be useful in the construction of smart musical instruments.

Assessment of communicative competence in adult patients with minimum response in intensive care units: A scoping review.

Few formal instruments exist to assess the communicative competence of patients hospitalized in intensive care units (ICUs). This can limit interventions by health professionals. To map the categories and instruments for assessing the communicative competence of adult patients with minimal response in ICUs. A scoping review was carried out following the Joanna Briggs Institute protocol between February and March 2022 and using the MEDLINE (PubMed), Scopus, Scielo, Business Source Complete (via EBSCOhost), Academic Search Complete (via EBSCOhost) and Web of Science databases, in Portuguese, English and Spanish. Eight studies met the inclusion criteria. The different communication and pain assessment protocols covered awareness, cognition, sensory capacity, motor capacity, language, speech and literacy. The present review offers a starting point for the construction of a formal assessment instrument to enable clinicians to implement an augmentative or alternative communication system (AACS) for the voluntary, independent and active participation of patients. What is already known on the subject Patients in ICUs are subject to various forms of treatment and continuous and intensive monitoring, compromising their capacity to communicate and actively participate (e.g., sharing symptoms and making decisions). Although there is some awareness of their disadvantage in such a regard, few protocols of assessment of communicative competence have been adapted to patients with a minimum response. What this paper adds to the existing knowledge The present review highlights different protocols for the assessment of communication and pain. They include the following categories: awareness, sensory capacity, auditory and visual acuity, positioning and motor capacity, language, speech, and literacy. The review offers a starting point for the construction of a formal assessment instrument encompassing the aforementioned categories, along with duly validated guidelines for its application. What are the potential or actual clinical implications of this work? Our formal assessment instrument takes into account the need to adapt to different patient profiles. It is hoped that it will provide speech therapists and other health professionals with the information required to implement an AACS in which patients participate actively.

Financial literacy to develop complex thinking skills: quantitative measurement in Mexican women entrepreneurs

The objective of the study was to validate the construction of a financial literacy measurement instrument aligned with complex thinking competencies in Mexican women entrepreneurs. By means of the construct validation method, the content was validated by expert judgment, validation by exploratory and confirmatory factor analysis, as well as internal consistency by means of a pilot test applied to a sample of 189 participants. A highly valid and reliable version was obtained, organized in four dimensions with a total of 23 items. This study examines and estimates the determinants of financial literacy for the first time under the light of complex reasoning.

Reliability Test, Homoscedasticity, and Heteroscedasticity Scatter Plot for Housemanship Instruments for Research Development

The development of research instruments is extremely important. The research indicated the construction of instruments among house officers during their housemanship. The independent variable and the dependent variable were both investigated as components of the research. Experience, conceptualization, experimentation, andcompetence are the items in both variables. In the initial phase, the researcher performed a study dependability analysis. The obtained alpha value indicates that all items have been accepted. The researcher then executes an analysis to generate a scatter plot of homoscedasticity and heteroscedasticity. The generated distribution must represent regression, with the data plot featuring regression-standardised residuals and regression-standardised projected value. The drawn representation should be oval for proof that the data is normal and distributed equally. An adequate distribution demonstrates that the research instruments are acceptable and trustworthy. The study's findings demonstrate that the distribution is oval. Therefore, both research objectives succeeded, including determining the trustworthiness of instrument development and recognising the commonality of homoscedasticity and heteroscedasticity scatter plots during instrument creation. A reliable instrument is essential for ensuring accuracy and research data.

The effects of technical nuances of design and construction of laparoscopic instruments on the solution of the problems of surgical treatment of the hepatobiliary zone pathology

The effects of technical nuances of design and construction of laparoscopic instruments on the solution of the problems of surgical treatment of the hepatobiliary zone pathology

Construction of Critical Reasoning Skills Assessment Instruments as Diagnostic Assessments in Physics Learning with Polytomus Scoring

Construction of Critical Reasoning Skills Assessment Instruments as Diagnostic Assessments in Physics Learning with Polytomus Scoring

Development and Validation of the Jawline Subject Satisfaction Scale

Introduction: Research in aesthetic medicine commonly includes evaluations of subject satisfaction with treatment results. However, conventional analytic methods typically generate statistically imprecise ordinal scores. To overcome this limitation, researchers have begun employing the Rasch model, an analytical framework grounded in item response theory. The Rasch model permits scale modifications capable of enhancing measurement accuracy. This study focuses on using the Rasch model to evaluate a scale measuring subject satisfaction following aesthetic treatments to the jawline. Objective: To develop and validate a multiitem, self-administered questionnaire measuring patient satisfaction with aesthetic treatment of the jawline. Methods: A 10-item questionnaire [The Jawline Subject Satisfaction Scale (JS3)] was devised to measure subject satisfaction following aesthetic treatments of the jawline. Each question was responded to using a 5-point Likert scale, with response selections ranging from “very much satisfied” to “very much dissatisfied” or “strongly agree” to “strongly disagree.” The scale's psychometric properties (reliability and separation for items and persons, item and person fit statistics, and unidimensionality and local independence) were validated using a Rasch model based on a dataset collected from a sample of forty subjects. Results: The results of the Rasch analysis revealed high internal consistency of the JS3, with a person reliability estimate of 0.86 and an item reliability estimate of 0.96. The separation estimates for persons and items were 2.50 and 4.72, respectively, demonstrating the scale's ability to differentiate between high and low responders and validating the instrument's construct. All infit and outfit values fell within the established range (0.5-1.5), and the data fit the model of unidimensionality and local independence. Raw score transformations into logits were conducted, which were then converted to Rasch measurements. These measurements are available for use in practice for conducting standard statistical analyses evaluating treatment and/or group effects. Conclusions: The application of the Rasch model produced a valid and reliable scale (ie, JS3) for measuring satisfaction with the appearance of the jawline following aesthetic treatments.

Ligamentous Augmentation to Prevent Proximal Junctional Kyphosis and Failure

Study Design: Biomechanical cadaveric study (level V). Objective: To evaluate the effectiveness of polyethylene bands looped around the supra-adjacent spinous process (SP) or spinal lamina (SL) in providing strength to the cephalad unfused segment and reducing junctional stress. Background: Proximal junctional kyphosis (PJK) is a pathologic kyphotic deformity adjacent to posterior spinal instrumentation after fusion constructs. Recent studies demonstrate a mismatch in stiffness between the instrumented construct and nonfused adjacent levels to be a causative factor in the development of PJK and proximal junction failure. To our knowledge, no biomechanical studies have addressed the effect of different methods of polyethylene band placement at the proximal junction. Materials and Methods: Twelve fresh frozen cadavers were divided into 3 groups of 4: pedicle screw-based instrumentation from T10 to L5 (“control”), T10–L5 instrumentation with a polyethylene band to the T9 “SP,” T10–L5 instrumentation with 2 polyethylene bands to the T9 “SL.” Specimens were tested with an eccentric (10 mm anterior) load at 5 mm/min for 15 mm or until failure occurred. Failure was defined by the inflection point on the load versus deformation curves. Linear regression was utilized to evaluate the effect of augmentation on the load-to-failure. Significance was set at 0.05. Results: Fractures occurred in all specimens tested. The mean peak load to failure was 2148 N (974–3322) for the SP group, and 1248 N (742–1754) for the control group (P &gt; 0.05) and 1390 N (1080–2004) for the SL group. No difference existed between the control group and the SP group in terms of fracture level (P &gt; 0.05). Net kyphotic angulation shows no differences among these 3 groups (P &gt; 0.05). Conclusion: Although statistical significance was not achieved, ligament augmentation to the SP increased mean peak load-to-failure in a cadaveric PJK model.