Bilateral occipital condyle fracture with an avulsion fracture of the foramen magnum: nonoperative care guided by a traction test. Illustrative case.

BACKGROUND: Bilateral occipital condyle fractures (OCFs) with involvement of the inferior clivus, otherwise known as "avulsion of the anterior foramen magnum," are an exceedingly rare injury with only a few published reports. OBSERVATIONS: A 24-year-old male presented with bilateral OCFs with involvement of the clivus after a motor vehicle accident. The patient had no neurological deficits and was successfully managed nonoperatively using a halo vest. The authors used a traction test to guide the duration of nonoperative care. The operative and nonoperative management of this rare injury is discussed with respect to other cases in the literature. LESSONS: External immobilization through a halo vest is an effective treatment option for bilateral OCFs with clivus involvement. The traction test can be used, along with computed tomography, to guide the duration of treatment.

What Is the Role of Traction Test Radiographs in the Preoperative Planning of Adolescent Idiopathic Scoliosis?

Lower instrumented vertebra (LIV) selection is critical to avoid complications like adding-on. This study aims to determine the usefulness of the traction test (TR) in selecting the LIV during surgery for adolescent idiopathic scoliosis (AIS). We analyzed 42 AIS patients with Lenke 1 curves who had preoperative, postoperative, and at least 12-month follow-up X-rays, as well as preoperative side bending (SB) and TR radiograms. Neutral vertebra (NV), stable vertebra (SV), lower instrumented vertebra (LIV), and Cobb angles were identified and compared on all radiographic images. In 23 cases, the TR resulted in SV proximalization compared to the preoperative X-rays, while in 8 cases, SV-TR was more distal. This distalization occurred in 50% of Lenke 1C curves, where a greater correction of the distal curve was found. NV-TR was proximal to NV-preop in 9 cases, while NV-SB was proximal in 22 cases. LIV was proximal to SV-TR in 8 cases, while it was proximal to SV-preop in 22. One patient with LIV proximal to SV-TR developed adding-on. In conclusion, the TR is crucial in AIS preoperative planning as it provides information distinct from that of standard X-rays and SB: (1) it better assesses gravitational stability than rotational stability; and (2) choosing LIV equal to or proximal to SV-TR may prevent adding-on, except in 'flexible' Lenke 1C curves where LIV should be equal or distal to SV-preop.

Traction mechanical characterization of porcine mitral valve annulus.

The Mitral Annulus (MA) is an anisotropic, fibrous, flexible and dynamical structure. While MA dynamics are well documented, its passive mechanical properties remain poorly investigated to complete the design of adequate prostheses. Mechanical properties in traction on four sections of the MA (aortic, left, posterior and right segments) were assessed using a traction test system with a 30 N load cell and pulling jaws for sample fixation. Samples were submitted to a 1.5 N pre-load, 10 pre-conditioning cycles. Three strain rates were tested (5 %/min, 7 %/min and 13 %/min), the first two up to 10 % strain and the last until rupture. High-resolution diffusion-MRI provided microstructural mapping of fractional anisotropy and mean diffusion within muscle and collagen fibres. Ten MA from porcine hearts were excised resulting in 40 tested samples, out of which 28 were frozen prior to testing. Freezing samples significantly increased Young Moduli for all strain rates. No significant differences were found between Young Moduli at different strain rates (fresh samples 2.4 ± 1.1 MPa, 3.8 ± 2.2 MPa and 3.1 ± 1.8 MPa for increasing strain rates in fresh samples), while significant differences were found when comparing aortic with posterior and posterior with lateral (p < 0.012). Aortic segments deformed the most (24.1 ± 9.4 %) while lateral segments endured the highest stress (>0.3 MPa), corresponding to higher collagen fraction (0.46) and fractional anisotropy. Passive machinal properties differed between aortic and lateral segments of the MA. The process of freezing samples altered their mechanical properties. Underlying microstructural differences could be linked to changes in strain response.

Traction Performance Evaluation of the Electric All-Wheel-Drive Tractor.

This study aims to design, develop, and evaluate the traction performance of an electric all-wheel-drive (AWD) tractor based on the power transmission and electric systems. The power transmission system includes the electric motor, helical gear reducer, planetary gear reducer, and tires. The electric system consists of a battery pack and charging system. An engine-generator and charger are installed to supply electric energy in emergency situations. The load measurement system consists of analog (current) and digital (battery voltage and rotational speed of the electric motor) components using a controller area network (CAN) bus. A traction test of the electric AWD tractor was performed towing a test vehicle. The output torques of the tractor motors during the traction test were calculated using the current and torque curves provided by the motor manufacturer. The agricultural work performance is verified by comparing the torque and rpm (T-N) curve of the motor with the reduction ratio applied. The traction is calculated using torque and specifications of the wheel, and traction performance is evaluated using tractive efficiency (TE) and dynamic ratio (DR). The results suggest a direction for the improvement of the electric drive system in agricultural research by comparison with the conventional tractor through the analysis of the agricultural performance and traction performance of the electric AWD tractor.

Modified superior oblique intrasheath tenectomy in A-pattern with superior oblique overaction.

BACKGROUND: To evaluate the effect of modified superior oblique intrasheath tenectomy (MSOIT) on superior oblique overaction (SOOA) with A-pattern. METHODS: We retrospectively reviewed the data of 66 patients (130 eyes) with SOOA and A-pattern underwent MSOIT at the nasal border of the superior rectus under an operating microscope between January 1, 2004 and December 31, 2018. The superior oblique (SO) tendon fibres were resected, and the sheath was preserved in all patients. The preoperative and postoperative SOOA, objective torsion, ocular motility, and A-pattern deviation findings were compared. The correlation between the preoperative A-pattern deviation and the corrected deviation was analysed. The average follow-up period was 33.45 ± 29.88 (range: 12-122) months. RESULTS: The mean SOOA deviation improved from 2.95 ± 0.54 to 0.34 ± 0.55 (P < 0.001), while the A-pattern deviation difference between upgaze and downgaze improved from 23.15 ± 7.59 prism diopters (PD) to 3.50 ± 2.90 PD (P < 0.001). The average objective fundus intorsion value improved from + 2.96 ± 0.58 to + 0.38 ± 0.60 (P < 0.001). The magnitude of correction in A-pattern was significantly correlated with the preoperative severity of A-pattern (r = 0.812, P < 0.001). CONCLUSIONS: MSOIT at the nasal border of the superior rectus (SR) under an operating microscope is safe and yields beneficial outcomes in patients with SOOA and A-pattern.

Correlation study in the measurements of oblique passive ductions and cyclorotation. / Estudio de correlación en las medidas de ducciones pasivas oblicuas y de ciclorrotación.

PURPOSE: To evaluate intraoserver and inteobserver repeatability of the "exaggerated forced duction test" or "oblique traction test" and the "excyclo and incyclo passive rotation test" or "cyclorotation traction test". METHODS: 44 eyes of 22 patients were evaluated under deep general anesthesia. Passive duction was tested on supraduction and infraduction by the "exaggerated duction test". The limitation on movement was graduated from 0 to - 4. Passive cyclorotation test was evaluated with retropulsion of the globe until the first resistance is noted. We used the Mendez ring and blue dots marked on the limbus to measure the amount of cyclorotation. The results obtained of excyclo and incyclorotation were recorded. All measurements were made in duplicate for each of the two observers. RESULTS: The intraclass correlation of the "oblique traction test" coefficient between the two observers was for the IO was 0,738 (95% confidence interval, 0,62-0,83) and 0,910 for the superior oblique (SO) (95% confidence interval, 0,85-0,94). The "cyclorotation traction test" intraclass correlation coefficient of the between the two observers was 0,827 (95% confidence interval, 0,74-0,89) for exclycloduction and 0,792 (95% confidence interval, 0,67-0,85) for inclycloduction. The percentage of patients within 5° of rotation interobserver was 84,1% for excyclorotation and 81,8% for inclyclorotation. Both tests had better correlation on the intraobserver than interobserver evaluation. CONCLUSIONS: Evaluation of the "oblique traction test" and "cyclorotation traction test" had moderate to good correlation between the two observers and good to excellent on the intraobserver evaluation.

Modeling of the human mandibular periosteum material properties and comparison with the calvarial periosteum.

Knowledge of mandibular periosteum mechanical properties is fundamental for understanding its role in craniofacial growth, in trauma and bone regeneration. There is a lack in the literature regarding mechanical behavior of the human periosteum, including both experimental and modeling aspects. The proposed study involves tensile tests of periosteum samples from different locations including two locations of human mandibular periosteum: lingual and vestibular, compared with samples from various locations of the calvarial periosteum. We propose to analyze the tensile response of the mandibular periosteum using a model, initially applied on the skin, and based on a structural approach involving the mechanical properties of the corrugation of the collagen. Two different approaches for the model parameters' identification are proposed: (1) identification from experimental curve fitting and (2) identification from histological study. This approach allows us to compare parameters extracted from the traction test fitting to structural parameters measured on periosteum histological slices. Concerning experimental aspects, we showed significant differences, in terms of stiffness, between calvarial and mandibular periostea. (The mean final stiffness is [Formula: see text] for the mandible versus [Formula: see text] for the calvaria.) About modeling, we succeed to capture the correct mechanical behavior for the periosteum, and the statistical analysis showed that certain parameters from the geometric data and traction data are significantly comparable (e.g., [Formula: see text] for [Formula: see text]). However, we also observed a discrepancy between these two approaches for the elongation at which the fibril has become straight ([Formula: see text]).

Suture and venous traction test analysis in dogs fixed in alcohol and preserved in saline solution / Análise de sutura e de teste de tração venosa em cães fixados em álcool e conservados em solução salina

The objective of this research was to determine in necropsied dogs the best time for fixation in ethylic alcohol (EA) and preservation in 30% sodium chloride aqueous solution (SCAS 30%), aiming micro-surgical training. Five groups of necropsied dogs (G1 to G5) were fixed with EA, and put in boxes containing EA for 30 (G2), 60 (G3), 90 (G4) or 120 days (G5). After that, each group was preserved in SCAS 30% for 120 days. The control group (G1) was composed by cadavers without fixation/preservation. At the end of each period, two fragments of external jugular vein per cadaver were collected, for traction test. Immediately after the collection, the cadavers femoral veins were evaluated (by 2 people) regarding the suture quality in binocular surgical microscope, and attributed scores from 0 (bad) to 5 (excellent), regarding the fresh samples. The average at the maximum rupture strength of the G3 fixation end (21.51N), such as the average of the G2 preserving end (21.62N) remained closer to the control group (19.98N) and the G2 was the group with the best score for venous suture training. The EA was efficient as a fixative just like SCAS as a dog cadavers' preservative. The small change of the traction test values, together with the best suture score, indicated the group kept for 30 days in EA and SCAS (G2) as the best for venous micro-surgical training.(AU)

O objetivo deste trabalho foi determinar, em cadáveres de cães, o melhor tempo para fixação em álcool etílico (AE) e conservação em solução aquosa de cloreto de sódio (SACS) a 30% visando o treinamento microcirúrgico. Cadáveres de cinco grupos (G1 a G5) foram fixados com AE e colocados em caixas contendo AE por 30 (G2), 60 (G3), 90 (G4) ou 120 days (G5). Depois, cada grupo foi conservado em SACS 30% por 120 dias. O grupo controle (G1) foi composto de cães sem fixação/conservação. Ao final de cada período, 2 fragmentos da veia jugular externa por cadáver foram coletados para o teste de tração. Imediatamente após a coleta, as veias femorais foram avaliadas (por 2 pessoas) em relação à qualidade da sutura em microscópio cirúrgico binocular, e atribuídos escores de 0 (péssimo) à 5 (excelente), em relação às amostras frescas. A média da força máxima de ruptura no G3 no final da fixação (21,51N), assim como a média do G2 no final da conservação (21,62N) foram as que mais se mantiveram próxima do grupo controle (19,98N) e o G2 foi o grupo com o melhor escore para treinamento da sutura venosa. O AE foi eficiente como fixador assim como a SACS foi efetiva na conservação de cadáveres de cães. A pequena alteração nos valores do teste de tração, junto com o melhor escore para sutura, indicaram o grupo mantido por 30 dias em AE e SACS (G2) como o melhor para treinamento venoso microcirúrgico.(AU)

Rupture limit evaluation of human cerebral aneurysms wall: Experimental study.

BACKGROUND AND PURPOSE: Rupture risk of intracranial aneurysms is a major issue for public healthcare. A way to obtain an individual rupture risk assessment is a main objective of many research teams in the world. For many years, we have investigated the relationship between the mechanical properties of aneurysm wall tissues and the rupture risk. In this work, we try to go further and investigate rupture limit values. METHODS: Following surgical clipping, a specific conservation protocol was applied to aneurysmal tissues in order to preserve their mechanical properties. Thirty-nine intracranial aneurysms (27 females, 12 males) were tested using a uniaxial tensile test machine under physiological conditions, temperature, and saline isotonic solution. These represented 24 unruptured and 15 ruptured aneurysms. Stress/strain curves were then obtained for each sample, and a fitting algorithm was applied following a Yeoh hyperelastic model with 2 parameters. Moreover, uniaxial tensile tests were conducted until rupture of samples to obtain values of stress and strain rupture limit. RESULTS: The significant parameter a C2 of the hyperelastic Yeoh model, allowed us to classify samples' rigidity following the terminology we adopted in previous papers (Costalat et al., 2011; Sanchez et al., 2013): Soft, Stiff and Intermediate. Moreover, strain/stress rupture limit values were gathered and analyzed thanks to the tissue rigidity, the status of the aneurysm (initially ruptured or unruptured) and the gender of the patient. CONCLUSION: Strain rupture limit was found quite stable around 20% and seems not to be correlated with the status of the aneurysm (initially ruptured or unruptured), neither with the gender of the patient. However, stretch and stress rupture limit seems not to be independent on the rigidity. The study confirms that ruptured aneurysms mainly present a soft tissue and unruptured aneurysms present a stiff material.

Estimation of the traction power of agricultural tractors from dynamometric tests / Estimativa da potência em tração de tratores agrícolas a partir de testes dinamométricos

ABSTRACT: The objective of this research was to predict, from dynamometric tests, the traction performance of agricultural tractors, without the need to employ the standard official tests carried out on concrete tracks. The evaluations were conducted at the experimental area of the Universidade Federal de Santa Maria, where an instrumented agricultural tractor was subjected to dynamic field traction tests and static tests in the laboratory, using an eddy currents dynamometer. It can be verified through the correlation analysis between the values obtained and the estimated values that, based on the prediction equations, a high correlation (r² = 0.99) was obtained between the power observed in the field and the estimated power obtained using dynamometric tests. Based on the analysis of the results obtained in this study, it can be stated that the traction performance of an agricultural tractor can be estimated from dynamometric tests. We concluded that the dynamic field tests can be replaced by static tests carried out in laboratories, which are generally less expensive.

RESUMO: O objetivo deste trabalho foi prever, a partir de testes dinamométricos, o desempenho em tração de tratores agrícolas, sem a necessidade de recorrer aos ensaios oficiais normalizados realizados em pistas de concreto. As avaliações foram conduzidas em área experimental, da Universidade Federal de Santa Maria, onde um trator agrícola instrumentado foi submetido a testes dinâmicos de tração, em superfície de campo e testes estáticos, em laboratório, utilizando-se freio dinamométrico elétrico, de correntes de Foucault. Pode-se verificar por meio da análise de correlação entre os valores obtidos e os valores estimados que, com base nas equações de predição, obteve-se alta correlação (r² = 0,99) entre a potência observada em campo e a potência estimada, a partir dos testes dinamométricos. Com base nas análises dos resultados obtidos neste estudo, pode-se afirmar que o desempenho em tração de um trator agrícola pode ser estimado a partir de testes dinamométricos. Conclui-se que, os ensaios dinâmicos em campo podem ser substituídos por ensaios estáticos, realizados em laboratórios, que em geral são menos onerosos.

Transcricothyroid Endoscopic Subglottic Surgery for Posterior Glottic Stenosis: A Case Report.

Posterior glottic stenosis (PGS) is a rare but life-threatening condition mostly caused by damage to the interarytenoid mucosa by an endotracheal tube. In surgical treatment of PGS, airway patency is prioritized, and the laryngeal functions involved in swallowing and phonation are considerably sacrificed. In the majority of cases, lateralization of a vocal fold or partial excision of a vocal fold and arytenoid cartilage results in glottal closure insufficiency and deterioration of phonatory function. We present the first report of transcricothyroid endoscopic subglottic surgery to treat a 46-year-old man with PGS who was intubated for 10 days. Postoperative hypofunction was not observed in the aerodynamic examination and acoustic analysis, and phonatory function has been maintained within normal limits.

Hair pull test: Evidence-based update and revision of guidelines.

BACKGROUND: The hair pull test lacks validation and has unclear pretest guidelines. OBJECTIVE: We sought to quantify normal hair pull test values and elucidate the effect of pretest hair washing and brushing. The impact of hair texture and lifestyle was also examined. METHODS: Participants (n = 181) completed a questionnaire recording demographics, medications, and hair health/history. A single hair pull test (scalp vertex) was performed. RESULTS: The mean number of hairs removed per pull was 0.44 (SD 0.75). There was no significant difference in the mean number of hairs removed regardless of when participants washed (P = .20) or brushed (P = .25) their hair. Hair pull test values were similar between Caucasian-, Asian-, and Afro-textured hair. There was no significant difference in hair pull values between participants taking medications affecting hair loss and participants not taking these medications (P = .33). Tight hairstyles did not influence hair pull test values. LIMITATIONS: Participant hair washing and brushing could not be controlled during the study, but this information was documented and analyzed. CONCLUSION: Normal values for the hair pull test should be reduced to 2 hairs or fewer (97.2% of participants). The current 5-day restriction on pretest hair washing can be reduced and brushing be made permissible.

Effect of Eye Movement Training Combined with Traction Test on Diplopia after Orbital Blowout Fracture / 中国康复理论与实践

@#Objective To compare the effects of simple eye movement training and eye movement training combined with traction test on the vision after orbital blowout fracture. Methods 143 cases with orbital blowout fracture after operation were divided into the experimental group (63 cases) and control group (80 cases). The experimental group was treated with eye movement training and passive traction test within 3 days after operation, while the control group was treated with eye movement training alone. The changes of diplopias of all patients were observed. Results The efficient rate in the experimental group was 93.6% (59/63), that of the control group was 72.5% (58/80). The effect of the experimental group was superior to that of the control group (P<0.01). Conclusion The eye movement training combined with traction test can improve the diplopia of the patients with orbital blowout fracture after operation.