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Biomechanical comparative study of the JuggerKnotTM soft anchor technique with other common mallet finger fracture fixationtechniques
No full textIntroduction
Mallet finger is a common injury involving either an extensor tendon rupture at its insertion or an avulsion fracture involving the insertion of the terminal extensor tendon. It is usually caused by a forceful blow to the tip of the finger causing sudden flexion or a hyperextension injury. Fracture at the dorsal aspect of the base of the distal phalanx is commonly associated with palmar subluxation of the distal phalanx. Most mallet finger injuries are recommended to be treated with immobilization of the distal interphalangeal joint in extension by splints. However, surgical fixation is still indicated in certain conditions such as open injuries, avulsion fracture involving at least one third of the articular surface with or without palmar subluxation of the distal phalanx and also failed splinting treatment. This study was designed to identify the strongest peak load resistance among four mallet finger fracture fixation methods, namely Kirschner wire fixation, pull-out wire fixation, tension-band wire fixation and the JuggerKnot? (Biomet) soft anchor fixation and to assess the role of the JuggerKnot? technique in mallet finger fixation.
Materials and method
Four different fixation techniques were assigned among twenty-four specimens (all fingers, no thumbs) from six cadaveric human hands in a randomized block fashion. Only one technique was performed on each finger. A downward load was applied to flex the distal phalanx and the maximum loading force was recorded. The load was tested at 30 degrees, 45 degrees and 60 degrees of flexion of the distal interphalangeal joint. Two separate data sets were performed for each finger before and after the osteotomy and fixation. The data underwent Shapiro-Wilk normality testing before analysis. The values of the mean peak load of the four groups were compared using the one-way analysis of variance test in SPSS version 19.0.
Result
All data points passed the Shapiro-Wilk test for normality. The mean peak load of the tension-band wiring group was 67.8N at 60 degrees of flexion which was significantly higher than the other three groups (p=0.008). The JuggerKnot? fixation had mean peak loads of 13.35N (30°), 22.51N (45°) and 32.96N (60°) which were all above the required load for mobilization. No complications of implant failure or fragmentation of the dorsal fragment was noted.
Discussion
The tension-band wire fixation was the strongest fixation method among the four. However it was cumbersome and it had the most soft tissue trauma among the four. No major difficulty was encountered during the testing. No fragmentation of the dorsal fragment was encountered during the procedures. The JuggerKnot? soft anchor fixation was a simple and easy technique and did not require trans-articular Kirschner wire fixation for protection. It could reduce and immobilize a grossly displaced dorsal fragment easily and allowed for safe immediate mobilization of the joint after operation as indicated by the peak load results. This fixation technique was a viable option for treating mallet finger injuries with a dorsal bony fragment size at least one-third of the articular surface with or without palmar subluxation of the distal phalanx.published_or_final_versionOrthopaedics and TraumatologyMasterMaster of Medical Science
Bridging the knowledge gaps in adolescent idiopathic scoliosis : an emphasis on growth, flexibility and outcome measures
No full textAdolescent idiopathic scoliosis is the commonest pediatric spinal deformity. Mild cases need only observation, but those who deteriorate may require bracing or surgery. Determining which patients should be treated requires a comprehensive assessment of a patient’s remaining growth potential. Most of the commonly used methods such as change in body height and arm span, onset of menarche, Risser sign, and bone age assessments are flawed by being retrospective, inconsistent, inaccurate and difficult to use. The distal radius and ulna (DRU) classification has been developed to be an accurate parameter with a large range of coverage from the very young to adolescents reaching skeletal maturity. In this thesis, the DRU classification was studied with reliability analysis, simplification and modification for easy use, and tested against other conventional growth parameters for predicting growth. Simplification of the grading scheme with only one single morphological change was performed and the reliability of this scheme was found to be excellent. It was also superior to commonly used growth parameters with strong prediction for peak growth and growth cessation, which are important time points for initiating and weaning brace treatment, respectively.
In addition to growth assessment, flexibility is important for prediction of treatment strategies and outcomes, but is often overlooked. There are many variations of flexibility assessments for AIS but the supine and fulcrum bending radiographs are two routinely used methods in our unit. The supine radiographs in particular have been used to determine the curve flexibility prior to brace wear. However, its ability to predict in-brace correction is unknown. In this thesis, supine correction of AIS curves was found to correlate highly with in-brace correction and is thus a useful guide to the expected correction achievable with brace treatment. Fulcrum bending radiographs have been shown to predict postoperative curve correction, fusion level selection, and instrumentation strategy. However, there are certain unknown factors that contribute to inaccurate predictions in some operative cases. This was hypothesized to be due to curves without uniform flexibility. AIS curves in this thesis were found to have different segmental flexibilities with the upper and middle segments stiffer than the lower segments. This proves that curve flexibility is not uniform and strategic placement of implants for curve correction should be performed. The stiffer upper and middle segments may require more screws for correction.
Postoperative assessments of AIS are also important to determine treatment outcomes. Although Cobb angle measurements are important radiological outcomes, patient perceived outcomes with objective scores are equally if not more relevant. Having a generic questionnaire such as the EuroQol 5-dimension 5-level (EQ-5D-5L) is necessary to compare the AIS treatment with other pathologies for cost-utility analyses. Yet, the role of the EQ-5D- 5L in assessment of AIS is unclear. In this thesis, validation of the EQ-5D-5L was performed in AIS patients followed by testing its responsiveness and mapping the disease-specific Scoliosis Research Society 22-item questionnaire onto the EQ-5D-5L. Results are promising which support its role in monitoring disease and treatment outcomes in AIS patients.published_or_final_versionSurgeryMasterMaster of Surger
Developmental spinal stenosis : from bedside to bench
No full textLumbar spinal stenosis is a common worldwide concern. Compression of the dural sac and nerve roots with spinal canal narrowing leads to symptoms of back or referred pain, radicular pain and claudication. Reoperation is not uncommon after decompression surgery for spinal stenosis. One possible reason for reoperation is pre-existing developmental narrowing of the spinal canal. Patients have generalized short pedicles and are likely at risk of multiple level compressions.
Developmental spinal stenosis (DSS) has a predilection for early age symptomatology. With a pre-existing narrowed bony spinal canal, only a small degree of degeneration and increase in the size of structures within the spinal canal will already cause symptomatic neural compression. This condition has not been well-understood in the past and its impact and etiology is unknown.
Our knowledge of this entity has been enhanced through the series of clinical and basic science studies. The imaging phenotype is better defined on both plain radiographs and magnetic resonance imaging (MRI). On MRI, critical stenosis has been defined as 14mm at L4, 14mm at L5 and 12mm at S1 with excellent sensitivity and specificity. On x-rays, a sagittal body width to pedicle width ratio of 3 is diagnostic of DSS. Its clinical implications as an independent risk factor for reoperation after decompression surgery and influence on ligamentum flavum pathology have been elucidated. Controlled for severity of disc degeneration and ligamentum flavum thickness, DSS has an adjusted odds ratio of 3.93 for reoperation at the adjacent level after an index decompression surgery.
The degree of fibrosis in ligamentum flavum was negatively correlated with the severity of developmental narrowing. This is in contrast to degenerative spinal stenosis in which the fibrosis is much more severe despite similar thickness of ligamentum flavum. The structures within the spinal canal will likely have similar maldevelopment potential. As a natural next step to understanding etiology, breakthroughs in the genetic etiology of the disease have been made. Candidate gene analysis identified the lipoprotein receptor related protein 5 (LRP5) gene on chromosome 11 to reach Bonferroni threshold of significance. This is a key component of the Wnt signaling pathway which is important for bone development. Finally, a mechanistic rat model mimicking circumferential compression has been created for future testing. The model produced the most severe functional deficits in the hindlimb postoperatively that are monitored with electrophysiology.
With these studies, we can translate our findings into a new clinical dogma for lumbar spinal stenosis. We now have a deeper understanding of the specific phenotype known as DSS which is not influenced by degenerative processes. It is an independent risk factor for multiple surgeries as only a mild degenerative change is adequate to give rise to symptoms. Routine screening of patients for developmental narrowing is important especially for patients requiring surgery to gauge the risk of further surgery. The results reported here are fuel for launching future clinical trials to determine the role of prophylactic decompression for at-risk spinal levels during the index operation.published_or_final_versionOrthopaedics and TraumatologyMasterDoctor of Medicin
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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