1,720,957 research outputs found
One-stage Revision ACL reconstruction with hamstring autograft results in satisfactory outcome
No full textObjectives: Revision anterior cruciate ligament (ACL) reconstruction is associated with poorer outcomes and higher rerupture rates when compared to primary ACL reconstruction. There is also a significant heterogeneity in surgical technique, number of stages, and graft options. We report a large single surgeon case series with hamstring autograft as a graft option. Methods: Observational series of revision ACL reconstructions performed by the senior author between 2005 and 2015 was carried out. Chart reviews and clinic follow-ups were performed with the following recorded – re-rupture rate, radiographic grading of osteoarthritis, KT-1000 arthrometer test, IKDC outcome scores and knee range of motion. All patients underwent single bundle four-strand hamstring autograft performed in one stage with use of new tunnels in majority of the cases. Results: 66 patients underwent hamstring autograft one-stage revision ACL reconstruction by Dr Jens Buelow. Chart review was carried out on all patients, and 26 (39%) were followed up in clinic and/or by phone with a mean follow up of 4.7 years. Outcomes included re-rupture rate of 4.5%, reoperation rate of 12%, mean visual analogue scale score of 7.6, mean side-to-side difference of 2.6 mm for KT-1000 arthrometer test, and mean IKDC score of 79. Of the 17 patients with radiographs, 40% had moderate osteoarthritis (grade 2 or 3) at follow-up. Conclusion: Revision ACL reconstruction can result in a satisfactory outcome when performed with a hamstring autograft in one stage. </jats:sec
Hybrid versus double bundle hamstring ACL reconstruction – a review of 626 cases
No full textObjectives: Since 2008, we have offered patients Hybrid ACL (hamstring plus LARS ligament) graft or double bundle hamstring graft. We allow the patients with Hybrid ACL to jog at 2 months and return to sports at 6 months. In comparison we allow the double bundle hamstring group to jog at 4 months and return to sports at 12 months. We considered the hybrid graft, due to its initial stiffness, would allow safe accelerated rehabilitation. Our primary aim was to establish whether Hybrid ACL graft has a higher failure rate compared to double bundle hamstring graft. Our secondary aim was to compare reoperation rates and clinic visit rates between the two groups. Methods: We performed a retrospective study of skeletally mature patients that underwent primary isolated ACL reconstruction by the senior author between 2008 and 2015 comparing double bundle hybrid ACL (DB Hyb), single bundle hybrid ACL (SB Hyb), and double bundle hamstring ACL (DB Ham) graft types. Charts were reviewed to assess reoperation rate, complication rate, re-rupture rate, and number of clinic visits. Graft tensioning positions, remnant sparing percentage, and concurrent meniscal procedures were reviewed as well. Results: 626 patients met the inclusion criteria. DB Hyb group had more males (77%) and a longer mean follow up (5.6 years) than the other two groups. Rerupture rates were 1.2% per year for DB hyb, 0.5% per year for SB Hyb, and 0.8% per year for DB Ham group. DB Hyb group trended towards a higher reoperation rate for arthrofibrosis compared to DB Ham (9.4% vs 4.7%, p-value 0.054). There was no difference in number of clinic visits between the 3 groups. Conclusion: Double bundle hybrid ACL group was associated with higher rates of arthrofibrosis surgery but equivalent rates of failure. </jats:sec
Arthroscopic assessment of patellofemoral tracking predicts patellar instability
No full textObjectives: Surgical management of patellar instability includes proximal realignment procedure such as MPFL reconstruction. The decision to add a distal realignment procedure of tibial tubercle transfer is based on severity of patellar instability judged on either TTTG distance or arthroscopic patellofemoral tracking. We set out to validate our use of arthroscopic patellofemoral tracking for patellar instability management algorithm by analyzing its reproducibility and whether it correlates with patellar instability. Methods: A prospective observational study was carried out at Perth Orthopaedic and Sports Medicine Centre. Patient clinical presentations were divided into three groups - patellofemoral instability, patellofemoral pain, and no patellofemoral symptoms. Standard technique included low flow arthroscopy with single anterolateral viewing portal. Height of the fluid bag and presence of a knee holder was recorded. Knee flexion angle where patella first centrally engages in the trochlear groove was defined as Patellofemoral Congruent Angle (PCA). PCA was estimated by the primary surgeon and the angle was confirmed using a sterile goniometer. A second surgeon, blinded to the initial assessment, then repeated the measurements. Surgeon estimation error, interobserver reliability, and correlation with clinical presentation was analysed. Results: 57 knees were assessed for interobserver reliability. Intra-class correlation was 0.994 between surgeon’s estimate and goniometer reading. Intra-class correlation was 0.992 between the two surgeon’s readings suggesting a very high correlation. 157 patients had their PCA recorded and compared with their diagnosis. Mean PCA was 40 degrees in normal patients, and 118 degrees in patellar instability (p-value <0.001). Conclusion: Arthroscopic assessment of patellofemoral tracking is reproducible and correlates with patellar instability. A cut-off value of 40 degrees is recommended to differentiate normal tracking from abnormal. </jats:sec
Arthroscopic assessment of patellofemoral tracking predicts patellar instability
No full textObjectives: Surgical management of patellar instability includes proximal realignment procedure such as MPFL reconstruction. The decision to add a distal realignment procedure of tibial tubercle transfer is based on severity of patellar instability judged on either TTTG distance or arthroscopic patellofemoral tracking. We set out to validate our use of arthroscopic patellofemoral tracking for patellar instability management algorithm by analyzing its reproducibility and whether it correlates with patellar instability. Methods: A prospective observational study was carried out at Perth Orthopaedic and Sports Medicine Centre. Patient clinical presentations were divided into three groups - patellofemoral instability, patellofemoral pain, and no patellofemoral symptoms. Standard technique included low flow arthroscopy with single anterolateral viewing portal. Height of the fluid bag and presence of a knee holder was recorded. Knee flexion angle where patella first centrally engages in the trochlear groove was defined as Patellofemoral Congruent Angle (PCA). PCA was estimated by the primary surgeon and the angle was confirmed using a sterile goniometer. A second surgeon, blinded to the initial assessment, then repeated the measurements. Surgeon estimation error, interobserver reliability, and correlation with clinical presentation was analysed. Results: 57 knees were assessed for interobserver reliability. Intra-class correlation was 0.994 between surgeon’s estimate and goniometer reading. Intra-class correlation was 0.992 between the two surgeon’s readings suggesting a very high correlation. 157 patients had their PCA recorded and compared with their diagnosis. Mean PCA was 40 degrees in normal patients, and 118 degrees in patellar instability (p-value <0.001). Conclusion: Arthroscopic assessment of patellofemoral tracking is reproducible and correlates with patellar instability. A cut-off value of 40 degrees is recommended to differentiate normal tracking from abnormal. </jats:sec
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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