62 research outputs found

    Near Surface Geophysical Archaeological Prospection at the Prehistoric Site of Akrotiri on Santorini/Thera

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    In February 2014 high-resolution ground penetrating radar and earth resistance tomography measurements have for the first time been used successfully for the distinct mapping of buried archaeological structures in the vicinity of the Bronze Age archaeological site of Akrotiri on Santorini/Thera in Greece

    The winking sign is an indicator for increased femorotibial rotation in patients with recurrent patellar instability

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    Purpose: Rotation of the tibia relative to the femur was recently identified as a contributing risk factor for patellar instability, and correlated with its severity. The hypothesis was that in patellofemoral dysplastic knees, an increase in femorotibial rotation can be reliably detected on anteroposterior (AP) radiographs by an overlap of the lateral femoral condyle over the lateral tibial eminence. Methods: Sixty patients (77 knees) received low-dose computed tomography (CT) of the lower extremity for assessment of torsional malalignment due to recurrent patellofemoral instability. Three-dimensional (3D) surface models were created to assess femorotibial rotation and its relationship to other morphologic risk factors of patellofemoral instability. On weight-bearing AP knee radiographs, a femoral condyle/lateral tibial eminence superimposition was defined as a positive winking sign. Using digitally reconstructed radiographs of the 3D models, susceptibility of the winking sign to vertical/horizontal AP knee radiograph malrotation was investigated. Results: A positive winking sign was present in 30/77 knees (39.0%) and indicated a 6.3 ± 1.4° increase in femorotibial rotation (p 15°) with 43% sensitivity and 90% specificity (AUC = 0.72; p = 0.002). A positive winking sign (with 2 mm overlap) disappeared in case of a 10° horizontally or 15° vertically malrotated radiograph, whereas a 4 mm overlap did not disappear at all, regardless of the quality of the radiograph. In absence of a winking sign, on the other hand, no superimposition resulted within 20° of vertical/horizontal image malrotation. Femorotibial rotation was positively correlated to TT-TG (R2 = 0.40, p = 0.001) and patellar tilt (R2 = 0.30, p = 0.001). Conclusions: The winking sign reliably indicates an increased femorotibial rotation on a weight-bearing AP knee radiograph and could prove useful for day-by-day clinical work. Future research needs to investigate whether femorotibial rotation is not only a prognostic factor but a potential surgical target in patients with patellofemoral disorders. Level of evidence: III. Keywords: Femorotibial rotation; Knee rotation; Patellar instability; Winking sig

    Tibial internal rotation in combined anterior cruciate ligament and high-grade anterolateral ligament injury and its influence on ACL length

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    BACKGROUND Assessment of combined anterolateral ligament (ALL) and anterior cruciate ligament (ACL) injury remains challenging but of high importance as the ALL is a contributing stabilizer of tibial internal rotation. The effect of preoperative static tibial internal rotation on ACL -length remains unknown. The aim of the study was analyze the effect of tibial internal rotation on ACL length in single-bundle ACL reconstructions and to quantify tibial internal rotation in combined ACL and ALL injuries. METHODS The effect of tibial internal rotation on ACL length was computed in a three-dimensional (3D) model of 10 healthy knees with 5° increments of tibial internal rotation from 0 to 30° resulting in 70 simulations. For each step ACL length was measured. ALL injury severity was graded by a blinded musculoskeletal radiologist in a retrospective analysis of 61 patients who underwent single-bundle ACL reconstruction. Preoperative tibial internal rotation was measured in magnetic resonance imaging (MRI) and its diagnostic performance was analyzed. RESULTS ACL length linearly increased 0.7 ± 0.1 mm (2.1 ± 0.5% of initial length) per 5° of tibial internal rotation from 0 to 30° in each patient. Seventeen patients (27.9%) had an intact ALL (grade 0), 10 (16.4%) a grade 1, 21 (34.4%) a grade 2 and 13 (21.3%) a grade 3 injury of the ALL. Patients with a combined ACL and ALL injury grade 3 had a median static tibial internal rotation of 8.8° (interquartile range (IQR): 8.3) compared to 5.6° (IQR: 6.6) in patients with an ALL injury (grade 0-2) (p = 0.03). A cut-off > 13.3° of tibial internal rotation predicted a high-grade ALL injury with a specificity of 92%, a sensitivity of 30%; area under the curve (AUC) 0.70 (95% CI: 0.54-0.85) (p = 0.03) and an accuracy of 79%. CONCLUSION ACL length linearly increases with tibial internal rotation from 0 to 30°. A combined ACL and high-grade ALL injury was associated with greater preoperative tibial internal rotation. This potentially contributes to unintentional graft laxity in ACL reconstructed patients, in particular with concomitant high-grade ALL tears. STUDY DESIGN Cohort study; Level of evidence, 3

    Influence of Bone Morphology on In Vivo Tibio-Femoral Kinematics in Healthy Knees during Gait Activities

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    An improved understanding of the relationships between bone morphology and in vivo tibio-femoral kinematics potentially enhances functional outcomes in patients with knee disorders. The aim of this study was to quantify the influence of femoral and tibial bony morphology on tibio-femoral kinematics throughout complete gait cycles in healthy subjects. Twenty-six volunteers underwent clinical examination, radiographic assessment, and dynamic video-fluoroscopy during level walking, downhill walking, and stair descent. Femoral computer-tomography (CT) measurements included medial condylar (MC) and lateral condylar (LC) width, MC and LC flexion circle, and lateral femoral condyle index (LFCI). Tibial CT measurements included both medial (MTP) and lateral tibial plateau (LTP) slopes, depths, lengths, and widths. The influence of bony morphology on tibial internal/external rotation and anteroposterior (AP)-translation of the lateral and medial compartments were analyzed in a multiple regression model. An increase in tibial internal/external rotation could be demonstrated with decreasing MC width β: -0.30 (95% CI: -0.58 to -0.03) (p = 0.03) during the loaded stance phase of level walking. An increased lateral AP-translation occurred with both a smaller LC flexion circle β: -0.16 (95% CI: -0.28 to -0.05) (p = 0.007) and a deeper MTP β: 0.90 (95% CI: 0.23 to 1.56) (p = 0.01) during the loaded stance phase of level walking. The identified relationship between in vivo tibio-femoral kinematics and bone morphology supports a customized approach and individual assessment of these factors in patients with knee disorders and potentially enhances functional outcomes in anterior cruciate ligament injuries and total knee arthroplasty

    Tibial tunnel enlargement is affected by the tunnel diameter-screw ratio in tibial hybrid fixation for hamstring ACL reconstruction

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    INTRODUCTION There is no evidence on screw diameter with regards to tunnel size in anterior cruciate ligament reconstruction (ACLR) using hybrid fixation devices. The hypothesis was that an undersized tunnel coverage by the tibial screw leads to subsequent tunnel enlargement in ACLR in hybrid fixation technique. METHODS In a retrospective case series, radiographs and clinical scores of 103 patients who underwent primary hamstring tendon ACLR with a hybrid fixation technique at the tibial site (interference screw and suspensory fixation) were obtained. Tunnel diameters in the frontal and sagittal planes were measured on radiographs 6 weeks and 12 months postoperatively. Tunnel enlargement of more than 10% between the two periods was defined as tunnel widening. Tunnel coverage ratio was calculated as the tunnel diameter covered by the screw in percentage. RESULTS Overall, tunnel widening 12 months postoperatively was 23.1 ± 17.1% and 24.2 ± 18.2% in the frontal and sagittal plane, respectively. Linear regression analysis revealed the tunnel coverage ratio to be a negative predicting risk factor for tunnel widening (p = 0.001). The ROC curve analysis provided an ideal cut-off for tunnel enlargement of > 10% at a tunnel coverage ratio of 70% (sensitivity 60%, specificity 81%, AUC 75%, p  10% in the frontal plane if the tunnel coverage ratio was < 70% (sagittal plane: OR 14.7, p = 0.001). Clinical scores did not correlate to tunnel widening. CONCLUSION Tibial tunnel widening was affected by the tunnel diameter coverage ratio. To minimize the likelihood of disadvantageous tunnel expansion-which is of importance in case of revision surgery-an interference screw should not undercut the tunnel diameter by more than 1 mm

    Three-dimensional analysis of functional femoral antetorsion and the position of the greater trochanter in high-grade patellofemoral dysplastic knees

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    BACKGROUND The relationship between functional femoral antetorsion, the greater trochanter (GT) position and anatomical antetorsion has been demonstrated in patients with a primary hip pathology. However, the functional antetorsion and GT position have not been analyzed in patellofemoral dysplastic knees. The aim of this study was to develop a three-dimensional (3D) measurement to quantify the functional femoral antetorsion and position of the GT and to analyze these measurements in a cohort of high-grade patellofemoral dysplastic knees. METHOD A 3D measurement was developed to analyze functional antetorsion and the axial position of the GT and assessed in 100 cadaveric femora. For validity and repeatability testing, inter- and intra-observer reliability were determined using intraclass correlation coefficients (ICCs). These measurements were then evaluated in a cohort of 19 high-grade patellofemoral dysplastic knees (Dejour type C, D). The relationship between anatomical antetorsion, functional antetorsion and GT position were reported. RESULTS Inter- and intra-reader reliability for 3D functional antetorsion and axial position of the GT demonstrated a minimum ICC of 0.96 (P < 0.001). Anatomical and functional antetorsion demonstrated a highly linear relationship (R2^{2} = 0.878; P < 0.001) in high-grade patellofemoral dysplastic knees. The mean difference between anatomical and functional antetorsion decreased with increasing anatomical antetorsion (R2^{2} = 0.25; P = 0.031, indicating a more anterior position of the GT relative to the femoral neck axis. CONCLUSION In high-grade patellofemoral dysplastic knees, the GT is located more anteriorly, relative to the femoral neck axis, with increasing anatomical antetorsion and correction osteotomy may result in an excessively anterior position of the GT

    Excessive femoral torsion is not associated with patellofemoral pain or instability if TKA is functionally aligned and the patella denervated

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    PURPOSE Recent data suggest that individual morphologic factors should be respected to restore preoperative patellofemoral alignment and thus reduce the likelihood of anterior knee pain. The goal of this study was to investigate the effect of excessive femoral torsion (FT) on clinical outcome of TKA. METHODS Patients who underwent TKA and complete preoperative radiographic evaluation including a long-leg radiograph and CT scan were included. 51 patients showed increased FT of > 20° and were matched for age/sex to 51 controls (FT < 20°). Thirteen patients were lost to follow-up. Thirty-eight matched pairs were compared after a 2 year follow-up clinically (Kujala and patellofemoral score for TKA) and radiographically (FT, frontal leg axis, TT-TG, patellar thickness, patellar tilt, and lateral displacement of patella). Functional alignment of TKA was performed (hybrid-technique). All patellae were denervated but no patella was resurfaced. RESULTS There was no significant difference between clinical scores two years after surgery between patients with normal and excessive FT (n.s.). Kujala score was 64.3 ± 16.7 versus 64.8 ± 14.4 (n.s.), and patellofemoral score for TKA was 74.3 ± 21 versus 78.5 ± 20.7 (n.s.) for increased FT group and control group, respectively. There was no correlation between preoperative FT and clinical scores. Other radiographic parameters were similar between both groups. No correlations between clinical outcomes and preoperative/postoperative frontal leg axis or total leg axis correction were found (n.s.). CONCLUSION If the leg axis deformity is corrected to a roughly neutral alignment during cemented TKA, including patellar denervation, then excessive FT was not associated with patellofemoral pain or instability. LEVEL OF EVIDENCE Prospective comparative study, level II

    Stirring the motivational soup: Within-person latent profiles of motivation in exercise

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    Background: The purpose of the present study was to use a person-oriented analytical approach to identify latent motivational profiles, based on the different behavioural regulations for exercise, and to examine differences in satisfaction of basic psychological needs (competence, autonomy and relatedness) and exercise behaviour across these motivational profiles. Methods: Two samples, consisting of 1084 and 511 adults respectively, completed exercise-related measures of behavioural regulation and psychological need satisfaction as well as exercise behaviour. Latent profile analyses were used to identify motivational profiles. Results: Six profiles, representing different combinations of regulations for exercise, were found to best represent data in both samples. Some profiles were found in both samples (e.g., low motivation profile, self-determined motivation profile and self-determined with high introjected regulation profile), whereas others were unique to each sample. In line with the Self-Determination Theory, individuals belonging to more self-determined profiles demonstrated higher scores on need satisfaction. Conclusions: The results support the notions of motivation being a multidimensional construct and that people have different, sometimes competing, reasons for engaging in exercise. The benefits of using person-oriented analyses to examine within-person interactions of motivation and different regulations are discussed. © 2017 The Author(s)

    L’espace rituel revisité : architecture et iconographie dans la Xestè 3 d’Akrotiri, Théra

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    The linking of the wall-painting compositions with specific walls and rooms in the monumental building Xeste 3 demonstrates the close relationship between Theran mural art and architecture, and confirms that the restoration and study of the wall-paintings is articulated equally with knowledge of the architectural idiom of a building and with the iconographic-interpretative interrelation of the wall-paintings themselves as thematic units. These paintings were designed and executed as parts of a composite iconographic code, axis of which are the stages and rituals in the initiation process of Theran adolescents in the Late Bronze Age, and were incorporated in a many-roomed, three-storey building that dominates a conspicuous public-open space, where the “secular” coexists with the “sacred” and the “religious”. For modern research, some of the scenes in the wall-paintings of Xeste 3 are of limited narrative value or of problematical affinity with others. We suppose that the events “narrated” reproduce images of rituals through the visual personification of defined social roles. The “images” of males and females with discreet characteristics of age, capacity and status, and their iconographic ranking within a dense mesh of reciprocally overlapping symbols, in stereotyped repetition (crocuses, flowers, rocks, swallows, monkeys, colours and properties of garments, jewellery) appear to visualize customary/ritual cycles which legitimize and endorse the biological and institutional development of members of the community, through rites of passage, ritual or mimetic “feats” and sanctioning eligibility to create a family. These cycles (of humans, animals, plants, as well as geometric motifs) are examined in association with the peculiar architecture of the building, and a series of issues is discussed, such as the manner of usage of the building and the limitations on access, the constructions and the moveable finds, and the role of light and of water. The architectural, iconographical and functional study of Xeste 3 places on a new basis the issue of “ritual” and “public/urban” space in the Creto-Mycenaean Aegean, favouring the conclusion of the complementary combination of these two concepts (traduction: Alexandra Doumas).Dans l’édifice monumental nommé Xestè 3, le rapport entre les fresques et certains murs ou certaines pièces démontre le lien étroit qui, à Théra, unissait la grande peinture et l’architecture. Il confirme également que la reconstruction et l’étude des fresques va de pair avec la connaissance de l’idiome architectural d’un bâtiment mais aussi avec une dialectique interprétative et iconographique qui relie entre elles les fresques elles-mêmes, en tant qu’entités thématiques. Ces œuvres peintes ont été tracées et exécutées comme les éléments d’un code iconographique synthétique, ayant pour axe les phases et les rites de la procédure d’initiation des jeunes gens de Théra à l’âge du Bronze récent. Elles ont été intégrées à un édifice de trois étages, aux pièces multiples, qui domine un lieu public en plein air prévu à cet effet, où le « civil » coexiste avec le « sacré » et le « religieux ». Pour le chercheur contemporain, plusieurs des scènes illustrées sur les peintures murales de la Xestè 3 ont une valeur narrative limitée, ou problématique dans leur relation contextuelle avec d’autres. À notre avis, les événements « narrés » reproduisent les images de rituels, au moyen de la personnification illustrée de certains rôles sociaux. Les « images » d’hommes et de femmes aux caractéristiques bien définies quant à leur âge, leur qualité et leur autorité, ainsi que leur hiérarchisation iconographique à travers un réseau dense de symboles, imbriqués dans la répétition de stéréotypes (crocus, fleurs, rochers, hirondelles, singes, couleurs et particularités des vêtements et des coiffures), permettent de visualiser des cycles de coutumes ou de rituels qui légalisent et valident le développement biologique et institutionnel des membres de la communauté au moyen de rites de passage, rituels consistant en imitation d’« exploits » et validation de la capacité à fonder une famille. Nous examinons ici ces cycles (hommes, animaux, plantes, mais aussi motifs géométriques) dans leur intégration à l’architecture particulière de l’édifice et nous discutons une série de questions, telles que le mode d’utilisation du bâtiment, les limitations d’accès, les installations et le mobilier, ainsi que le rôle de la lumière et de l’eau. L’étude architecturale, iconographique et fonctionnelle de la Xestè 3 pose, sur des bases nouvelles, la question de l’espace « rituel » et de l’espace « civil/public » dans le monde créto-mycénien ; elle arrive à une conclusion qui privilégie l’association complémentaire des deux notions.Vlachopoulos Andreas G. L’espace rituel revisité : architecture et iconographie dans la Xestè 3 d’Akrotiri, Théra. In: Espace civil, espace religieux en Égée durant la période mycénienne. Approches épigraphique, linguistique et archéologique. Actes des journées d'archéologie et de philologie mycéniennes, Lyon, 1er février et 1er mars 2007. Lyon : Maison de l'Orient et de la Méditerranée Jean Pouilloux, 2010. pp. 173-198. (Travaux de la Maison de l'Orient et de la Méditerranée, 54
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