559 research outputs found
The use of ultrasound in the assessment of the glenoid labrum of the glenohumeral joint. Part I: Ultrasound anatomy and examination technique
No full textThe glenohumeral joint is a spherical articulation with a remarkable range of motion in
several planes and decreased stability. The maintenance of joint stability is influenced
by the functioning of specific muscle groups in the shoulder region, a complex system of
ligaments reinforcing the joint capsule, and the labrum which augments the glenoid fossa.
Lesions of the aforementioned structures require accurate diagnosis prior to a decision
for operative treatment. Ultrasound is one of the imaging methods that has been widely
used in the assessment of various shoulder pathologies. In the author opinion, this imaging
modality may also be applied for the evaluation of labral tears. Being attached along
the glenoid rim, the labrum forms a collar deepening the glenoid fossa thus increasing
area of its contact with the head of the humerus. To better describe the location of lesions,
the glenoid labrum is usually divided into certain zones. Most of them may be visualized
sonographically. The US examination of the posterior labrum can be performed during
evaluation of the infraspinatus and teres minor muscles. The anterior labrum along with
capsulolabral complex is seen at the glenoid edge under the subscapularis tendon. Sonographic
examination of the inferior labrum is best performed using axillar approach.
The superior labrum is only partially available for US examination. A crucial part of the
sonographic assessment of the labrum is the dynamic examination during rotation of the
upper extremity. The paper presents normal sonographic anatomy of the glenoid labrum
and technique of the examination
'Making its own history': New Zealand historical fiction for children,1862-2008
No full textThis thesis considers historical fiction for children and young people dealing with New Zealand history from the arrival of the first Polynesian settlers to the end of the nineteenth century. It provides both a comprehensive survey of historical novels published between 1862 and the end of 2008, and an analysis of the way the same historical events and periods have been depicted in historical novels written at different times. Individual chapters discuss books set during specific historical periods or dealing with particular events - the pre-European period, early contact, nineteenth century immigration, the New Zealand Wars, the gold rushes, and the colonial period - in chronological order of publication. Since children's literature is particularly adept at reflecting and promoting the dominant ideas of the society in which it is produced, the chronological consideration of these texts reveals contemporary attitudes to such issues as race relations, gender roles, class, war and conflict, and concepts of national identity, as well as the way historical fiction has responded to societal changes since the 1860s.
The predominant themes of historical fiction set prior to 1900 are: the arrival of settlers in New Zealand; encounters with the country's indigenous inhabitants; the taming of the often hostile landscape; the assertion of the settlers' claims to 'belong' in their new land; and the establishment of New Zealand as a nation with distinctive characteristics. There are perceptible nuances and differences in the way these themes are discussed depending on the historical moment in which individual authors are writing. Novels of the Victorian period and early twentieth century reflect the imperialistic and evangelistic ethos of the time, and present the British settlers' right to colonize the land and the ensuing dispossession of Māori as largely unproblematic. Subsequent historical novels, particularly those written since the 1960s, offer a more inclusive version of New Zealand history, although the lack of historical fiction for children by Māori writers means that Eurocentric views of history continue to dominate, and that all representations of Māori and their history are mediated through Pakeha writers.
Shifts in social attitudes have resulted in changes in the treatment of Māori in historical novels for children, and similar changes have occurred in the portrayal of gender, class, and ethnicity. The passage of time has seen increased agency and a wider variety of roles allocated to Māori, female and working class characters, as well as greater ethnic diversity. Developments in New Zealand historiography are also reflected in fiction, although at times historical fiction prefigures written histories, or provides alternative views by depicting the experience of women, children and Māori, who often did not feature in conventional histories. While many historical novels for children, especially the earlier texts, are adventure stories set in the past and are not necessarily concerned with historical verisimilitude, an increasing number attempt to present authentic recreations of historical periods, including accounts of actual people and events, based on extensive research, and reinforced with peritextual material in the form of historical notes, bibliographies, maps and photographs.
The role of New Zealand historical fiction for children and young people has been not only to entertain young readers and inform them about their country's past, but to create and foster a sense of national identity
The influence of the acetabular labrum on hip joint cartilage consolidation : a poroelastic finite element model
No full textThe goal of this study was to investigate the influence of the acetabular labrum on the consolidation, and hence the solid matrix strains and stresses, of the cartilage layers of the hip joint. A plane-strain finite element model was developed, which represented a coronal slice through the acetabular and femoral cartilage layers and the acetabular labrum. Elements with poroelastic properties were used to account for the biphasic solid/fluid nature of the cartilage and labrum. The response of the joint over an extended period of loading (10,000 s) was examined to simulate the nominal compressive load that the joint is subjected to throughout the day. The model demonstrated that the labrum adds an important resistance in the flow path of the fluid being expressed from the cartilage layers of the joint. Cartilage layer consolidation was up to 40% quicker in the absence of the labrum. Following removal of the labrum from the model, the solid-on-solid contact stresses between the femoral and acetabular cartilage layers were greatly increased (up to 92% higher), which would increase the friction between the joint surfaces. In the absence of the labrum, the centre of contact shifted towards the acetabular rim. Subsurface strains and stresses were much higher without the labrum, which could contribute to fatigue damage of the cartilage layers. Finally, the labrum provided some structural resistance to lateral motion of the femoral head within the acetabulum, enhancing joint stability and preserving joint congruity.
Author Keywords: Hip joint; Labrum; Finite elemen
Arthroscopic Repair of a Type VIII Superior Labrum Anterior Posterior Tear
No full textBackground: Type VIII superior labrum anterior posterior (SLAP) tears are described as SLAP type II tears with posterior extension to the posterior inferior glenohumeral ligament. These tears are a common source of pain, instability, and decreased function in active individuals, particularly overhead or throwing athletes. Indications: Type VIII SLAP tears can cause pain and loss of sports performance, especially in a throwing athlete. This patient is a quarterback and pitcher who had magnetic resonance imaging and arthroscopic evidence of a type VIII SLAP tear with pain and inability to throw at his preinjury level. Technique Description: In the lateral decubitus position, a standard posterior portal is established along with anterior and accessory lateral portals. A type VIII SLAP tear is identified and the arm is taken out of balanced suspension traction and placed in abduction and external rotation which shows displacement of the posterior labrum and peelback of the superior labrum indicating pathologic labral instability. The labrum is then elevated and glenoid prepared to achieve healthy bleeding bone. Tape sutures are then passed around the labrum and placed into a glenoid anchor starting superiorly and continuing the repair posteroinferiorly. Three anchors were placed in the superior labrum using a percutaneous technique, with 2 more placed from the posterior portal to complete the 5-anchor repair. The posterior portal is then closed with a single monofilament suture to prevent a potential stress riser in the capsule. Results: The literature suggests that athletes with type VIII SLAP tears can expect improved functional outcomes and high return to play rates (>90%); however, only 50% to 70% of throwing athletes return to the same level of play. Discussion/Conclusion: Type VIII SLAP tears are an important cause of shoulder pain and dysfunction, particularly in overhead athletes. Arthroscopic repair of type VIII SLAP tears can improve functional outcomes and ability to return to sport; however, throwing athletes experience lower rates of return to previous level. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication
Effect of vagus nerve stimulation in an adult patient with Dravet syndrome: contribution to sudden unexpected death in epilepsy risk reduction?
No full textWe report on a patient who developed, from 5 months of age, multiple seizure types, including myoclonic, associated with severe psychomotor delay, leading to the diagnosis of Dravet syndrome. Over the years, he developed refractory epilepsy and was implanted with a vagus nerve stimulator at the age of 19. After 3 months, he experienced a progressive improvement of partial and generalized seizures, with a >90% reduction, and better alertness. This meaningful clinical improvement is discussed in the light of the sudden unexpected death in epilepsy risk, which is high in this setting, and seems remarkably diminished in our patient in view of the reduction of generalized convulsions
Arthroscopic Glenoid Labrum Repair of Left Shoulder in a Male With Ehlers-Danlos Syndrome
No full textEhlers-Danlos syndrome (EDS) is an inherited connective tissue disorder that has been classified into several primary types. The clinical characteristic of EDS is hypermobility of the joints, hyperextensibility and fragility of the skin, and hemorrhage tendency. For many patients, the hypermobile joints become a serious problem. We present the case of a 19-year-old male diagnosed with EDS, with recurrent dislocations of his left shoulder, hyperextensibility and fragility of the skin, and a carp-mouth-shaped scar of the forearm. After 4 years of nonoperative treatment, we performed an arthroscopic glenoid labrum repair of left shoulder. At a 6-year follow-up, the patient has no instability in the left shoulder. We believe that glenoid labrum repair is a viable method for treating recurrent dislocations for patients with EDS. It is strongly suggested to check coagulation function of patients to avoid substantial bleeding when decorticating the glenoid rim, to ensure a conservative postoperative rehabilitation.National Natural Science Foundation of China [81672234]; Shenzhen Science Technology Innovation Council [GCZX2015043017241191]SCI(E)ARTICLE9-10478-48210
The clinical and genetic heterogeneity of paroxysmal dyskinesias
Get PDFParoxysmal dyskinesia can be subdivided into three clinical syndromes: paroxysmal kinesigenic dyskinesia or choreoathetosis, paroxysmal exercise-induced dyskinesia, and paroxysmal non-kinesigenic dyskinesia. Each subtype is associated with the known causative genes PRRT2, SLC2A1 and PNKD, respectively. Although separate screening studies have been carried out on each of the paroxysmal dyskinesia genes, to date there has been no large study across all genes in these disorders and little is known about the pathogenic mechanisms. We analysed all three genes (the whole coding regions of SLC2A1 and PRRT2 and exons one and two of PNKD) in a series of 145 families with paroxysmal dyskinesias as well as in a series of 53 patients with familial episodic ataxia and hemiplegic migraine to investigate the mutation frequency and type and the genetic and phenotypic spectrum. We examined the mRNA expression in brain regions to investigate how selective vulnerability could help explain the phenotypes and analysed the effect of mutations on patient-derived mRNA. Mutations in the PRRT2, SLC2A1 and PNKD genes were identified in 72 families in the entire study. In patients with paroxysmal movement disorders 68 families had mutations (47%) out of 145 patients. PRRT2 mutations were identified in 35% of patients, SLC2A1 mutations in 10%, PNKD in 2%. Two PRRT2 mutations were in familial hemiplegic migraine or episodic ataxia, one SLC2A1 family had episodic ataxia and one PNKD family had familial hemiplegic migraine alone. Several previously unreported mutations were identified. The phenotypes associated with PRRT2 mutations included a high frequency of migraine and hemiplegic migraine. SLC2A1 mutations were associated with variable phenotypes including paroxysmal kinesigenic dyskinesia, paroxysmal non-kinesigenic dyskinesia, episodic ataxia and myotonia and we identified a novel PNKD gene deletion in familial hemiplegic migraine. We found that some PRRT2 loss-of-function mutations cause nonsense mediated decay, except when in the last exon, whereas missense mutations do not affect mRNA. In the PNKD family with a novel deletion, mRNA was truncated losing the C-terminus of PNKD-L and still likely loss-of-function, leading to a reduction of the inhibition of exocytosis, and similar to PRRT2, an increase in vesicle release. This study highlights the frequency, novel mutations and clinical and molecular spectrum of PRRT2, SLC2A1 and PNKD mutations as well as the phenotype-genotype overlap among these paroxysmal movement disorders. The investigation of paroxysmal movement disorders should always include the analysis of all three genes, but around half of our paroxysmal series remain genetically undefined implying that additional genes are yet to be identified
Arthroscopic Repair of a 360° Labrum and Full-Thickness Rotator Cuff Tear After Shoulder Dislocation
No full textBackground: Rotator cuff tears after anterior shoulder instability are more common in patients >40 years of age and rare in younger patients where shoulder instability is most common. Although infrequent, little data exist on the evaluation of combined labral and rotator cuff tears in athletes. Indications: Combined rotator cuff and labral tears in the young patient population have a high risk of recurrent instability and require unique intraoperative and postoperative considerations. This patient is a Division 1 collegiate wrestler who sustained a 360° labral and full-thickness rotator cuff tear after an acute traumatic anterior shoulder dislocation. Technique Description: The lateral decubitus position is utilized and a posterior viewing portal is established along with anterior and accessory lateral portals. The 360° labral tear is first addressed by appropriately preparing the glenoid creating a quality healing surface. Tape sutures are then utilized to perform a knotless anterior labral repair. The superior labrum, anterior to posterior (SLAP) and then posterior labral repair are sequentially performed. The posterior portal is closed with a polydioxanone (PDS) suture to prevent a stress riser in the capsule. The rotator cuff tear is then repaired in a knotless double row configuration after appropriate greater tuberosity preparation. Results: Recent studies evaluating athletes with combined rotator cuff and labral pathology who underwent arthroscopic repair reported 90% good to excellent satisfaction with 77% returning to pre-injury level of athletics. Although few studies have evaluated combined labral and rotator cuff repair and concerns with stiffness exist, the current literature and the authors own experience have found good outcomes following single-stage repair. Discussion/Conclusion: Combined labral and rotator cuff tears after anterior shoulder dislocation in the young athletic population are rare and can be challenging to treat. Although there is limited data on these combined injuries in young athletic populations, the current literature and authors’ experience support single stage surgical treatment of combined labral and rotator cuff tears which typically result in improved patient reported outcomes and return to sport. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication
Early Deformation of Hip Articular Cartilage Under A High Load Before and After Labral Excision
Get PDFThis is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Background: It has been reported that the function of the labrum is to ensure that an increased surface area encountered the femoral head and spares the cartilage from excessive strain. The purpose of this study was to determine whether early deformation of the hip articular cartilage occurs under high-load conditions in the presence/absence of the labrum.
Methods: The hip joints of 4 beagle dogs were retrieved. A continuous static load of 80 Kg was applied for 2.5 hours. Magnetic resonance imaging (MRI) was performed immediately after the loading and at 30, 60, 90, 120, and 150 minutes after the loading. The load was then removed, and the specimens were stored for 14 h to allow the cartilage to recover. The labrum was then carefully removed, and the experiment was performed again.
Results: The maximum percentage change in cartilage thickness was 35.3 ± 17.4% when the labrum was intact and 55.7± 7.5% after the labrum had been excised (p=0.060). Labral excision resulted in a reduction in cartilage thickness. Cartilage thickness was significantly decreased in the normal and labral excision models immediately after loading (p=0.003 and p=0.022, respectively).
Conclusion: The labrum plays a role in dispersing loads equally across the joint cartilage and reduces the load placed on the maximum weight-bearing region of cartilage. Early articular cartilage deformation occurred under high-load conditions both before and after the excision of the labrum
Knotless Labral Repair Using the Inversion Technique in Hip Arthroscopy
No full textBackground: Hip arthroscopy is technically demanding with a steep learning curve, and labral repair is an important component of the surgical treatment of femoroacetabular impingement (FAI) syndrome. As hip arthroscopy indications and techniques are evolving, it is important to remain focused on teaching techniques that are easily mastered and have a measurable benefit to patient outcomes. Indications: Patients with FAI syndrome and labral tear who have failed conservative treatment may benefit from hip arthroscopy, labral repair, and femoroplasty. Technique Description: Labral repair is an essential component of the surgical treatment of FAI syndrome. The hip is accessed in standard fashion, and multiple knotless anchors are used for labral repair. Repair sutures are passed around the labrum in an inverted fashion. This inversion technique ensures the labrum is not everted away from the acetabular rim and that the final position of the labrum will restore a good suction seal on the femoral head. Femoroplasty and capsule closure are always performed. Results: Patients can reliably expect improvements in hip pain and function. A cohort of 62 patients was investigated, and these patients demonstrated significant improvement in multiple patient-reported outcomes related to physical function, activity, and pain at 2 years after hip arthroscopy. Forty-seven percent stated they felt “completely better” at 2 years postoperatively. Discussion/Conclusion: Good hip arthroscopy technique in the proper patient can yield excellent results. The inversion labral repair technique reliably restores the suction seal and prevents eversion of the labrum to preserve normal function. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication
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