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Joint Structure (joint + structure)
Selected AbstractsThe Colorado Haemophilia Paediatric Joint Physical Examination Scale: normal values and interrater reliabilityHAEMOPHILIA, Issue 1 2007M. R. HACKER Summary., ,Persons with haemophilia often experience their first joint haemorrhage in early childhood. Recurrent bleeding into a joint may lead to significant morbidity, specifically haemophilic arthropathy. Early identification of the onset and progression of joint damage is critical to preserving joint structure and function. Physical examination is the most feasible approach to monitor joint health. Our group developed the Colorado Haemophilia Paediatric Joint Physical Examination Scale to identify earlier signs of joint degeneration and incorporate developmentally appropriate tasks for assessing joint function in young children. This study's objectives were to establish normal ranges for this scale and assess interrater reliability. The ankles, knees and elbows of 72 healthy boys aged 1 through 7 years were evaluated by a physical therapist to establish normal ranges. Exactly 10 boys in each age category from 2 to 7 years were evaluated by a second physical therapist to determine interrater reliability. The original scale was modified to account for the finding that mild angulation in the weight-bearing joints is developmentally normal. The interrater reliability of the scale ranged from fair to good, underscoring the need for physical therapists to have specific training in the orthopaedic assessment of very young children and the measurement error inherent in the goniometer. Modifications to axial alignment scoring will allow the scale to distinguish healthy joints from those suffering frequent haemarthroses. [source] Association between condylar position, joint morphology and craniofacial morphology in orthodontic patients without temporomandibular joint disordersJOURNAL OF ORAL REHABILITATION, Issue 11 2003K. Kikuchi summary, The present study investigated condylar position and joint morphology in adolescent patients and elucidated the possible association between the joint structure and condylar position, and craniofacial morphology. Sixty-five adolescent patients were selected as subjects and their tomograms and lateral cephalograms were analysed. No significant differences in joint spaces were found between the right and left temporomandibular joints. Both the condyles in this population were located slight anteriorly in the glenoid fossa. With respect to the association between condylar position, joint morphology and craniofacial morphology, the ramus plane angle also exhibited significant negative correlations with posterior, lateral and medial joint spaces. Furthermore, there was a significant negative correlation between the gonial angle and the anterior joint space. These findings imply that the condyle was likely to show more posterior position in the glenoid fossa when the mandible exhibited clockwise rotation. In conclusion, the condyle in the adolescent subjects showed a symmetrical anterior position relative to the glenoid fossa. In addition, the joint spaces and it ratios were significantly related to the craniofacial morphology associated with vertical dimension. It is suggested that the condylar position may be affected by craniofacial growth pattern. [source] Nonlinear FEM Simulation of Air Cushion Vehicle (ACV) Skirt Joint Under Tension LoadingNAVAL ENGINEERS JOURNAL, Issue 2 2009JIA ZHOU The mechanical properties of an air cushion vehicle (ACV) skirt cloth, which is a nonlinear rubber-coated fabric, are tested on a Series IX 4465 electron tension machine manufactured by Instron Company. Compared with the Mooney,Rivlin and Ogden form, the second-order Mooney,Rivlin form agrees with the model test result better. The ultimate bearing capacity of an ACV skirt joint structure is tested on a mechanical tension machine and the ultimate load is recorded manually. Then, considering the contact effect of each assembly and the large-displacement of skirt elements, a nonlinear finite element method (FEM)-based simulation process of an ACV skirt joint structure under tension loading is presented. The simulation process comprises three steps: assembly of parts, bolts' tightening, and tensioning the skirt cloth. Under these loadings, the stress distribution and deformation of the skirt cloth, and the cloth broken locations and directions are obtained. These results agree well with the test results. As for the ultimate bearing capacity of the skirt joint, the simulation result is slightly smaller than the test result. Thus, this FEM-based simulation method is proven to be reliable and relatively conservative. [source] Loss of cartilage structure, stiffness, and frictional properties in mice lacking PRG4ARTHRITIS & RHEUMATISM, Issue 6 2010Jeffrey M. Coles Objective To assess the role of the glycoprotein PRG4 in joint lubrication and chondroprotection by measuring friction, stiffness, surface topography, and subsurface histology of the hip joints of Prg4,/, and wild-type (WT) mice. Methods Friction and elastic modulus were measured in cartilage from the femoral heads of Prg4,/, and WT mice ages 2, 4, 10, and 16 weeks using atomic force microscopy, and the surface microstructure was imaged. Histologic sections of each femoral head were stained and graded. Results Histologic analysis of the joints of Prg4,/, mice showed an enlarged, fragmented surface layer of variable thickness with Safranin O,positive formations sometimes present, a roughened underlying articular cartilage surface, and a progressive loss of pericellular proteoglycans. Friction was significantly higher on cartilage of Prg4,/, mice at age 16 weeks, but statistically significant differences in friction were not detected at younger ages. The elastic modulus of the cartilage was similar between cartilage surfaces of Prg4,/, and WT mice at young ages, but cartilage of WT mice showed increasing stiffness with age, with significantly higher moduli than cartilage of Prg4,/, mice at older ages. Conclusion Deletion of the gene Prg4 results in significant structural and biomechanical changes in the articular cartilage with age, some of which are consistent with osteoarthritic degeneration. These findings suggest that PRG4 plays a significant role in preserving normal joint structure and function. [source] Strength estimation of ceramic,metal joints with various interlayer thicknessFATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 5 2003M. TAKAHASHI ABSTRACT Residual stresses generated by the mismatch of thermal expansion coefficients of ceramics and metals affect the strength of ceramic,metal joints. An interlayer metal can be inserted between the ceramic and metal in order to relax this stress. An analysis was carried out of the residual stresses produced during joint-cooling and in 4-point bending tests. The effects of interlayer thickness on ceramic,metal joint strength were then studied by considering a superimposed stress distribution of the residual stress and the bending stress. Finally, joint strength was estimated from fracture mechanics and strength probability analysis by considering the residual stress distribution, defect size and position of pre-existing defects in the ceramic parts. As a result of this study, we suggest an optimum material selection and interlayer thickness for ceramic,metal joint structures. This approach is generally suitable for the design of electrical and mechanical structures. [source] Static orthoses in the prevention of hand dysfunction in rheumatoid arthritis: a review of the literatureMUSCULOSKELETAL CARE, Issue 2 2005DipCOT Lecturer in Occupational Therapy, Jo Adams MSc Abstract Static orthoses are recommended for individuals who have early rheumatoid arthritis (Scottish Intercollegiate Guidelines Network, 2002; College of Occupational Therapists, 2003). These orthoses aim to rest and immobilize weakened joint structures and decrease local inflammation (Janssen et al., 1990; Nicholas et al., 1982); correctly position joints (Nordenskiöld, 1990; Ouellette, 1991); minimize joint contractures (McClure et al., 1994); increase joint stability (Kjeken et al., 1995); relieve pain (Feinberg, 1992; Callinan and Mathiowetz, 1996; Kjeken et al., 1995) and improve function (Janssen et al., 1990; Pagnotta et al., 1998; Nordenskiöld, 1990). Wrist and hand orthoses have been routinely prescribed for individuals with rheumatoid arthritis (RA) for the last 30 years with limited evidence that they are effective in achieving their purported aims. This article reviews the possible deterioration in hand structure that can occur in RA and discusses the theoretical basis for the application of static orthoses in RA. The evidence for the effectiveness of four commonly used static orthoses is then examined. Copyright © 2005 Whurr Publishers Ltd. [source] Physical Medicine and Rehabilitation (85)PAIN PRACTICE, Issue 1 2001Erbil Dursun Glenohumeral joint subluxation and reflex sympathetic dystrophy in hemiplegic patients. (Kocaeli University, Kocaeli, Turkey) Arch Phys Med Rehabil 1999; 81:944,946. This is a case-controlled study of the relationship between glenohumeral joint subluxation and reflex sympathetic dystrophy (RSD) in hemiplegic patients set in an inpatient rehabilitation hospital. Thirty-five hemiplegic patients with RSD (RSD group) and 35 hemiplegic patients without RSD (non-RSD group) were included in this study. Patients with rotator cuff rupture, brachial plexus injury, or spasticity greater than stage 2 on the Ashworth scale were excluded. Both the RSD and non-RSD groups were assessed for presence and grade of subluxation from radiographs using a 5-point categorization. The degree of shoulder pain of the non-RSD group was assessed by a visual analogue scale of 10 points. Glenohumeral subluxation was found in 74.3% of the RSD group and 40% of the non-RSD group (P = 0.004). In the non-RSD group, 78.6% of the patients with subluxation and 38.1% of the patients without subluxation reported shoulder pain (P = 0.019). No correlation was found between the degree of shoulder pain and grade of subluxation in the non-RSD group (P = 0.152). Conclude that the findings suggest that shoulder subluxation may be a causative factor for RSD. Therefore, prevention and appropriate treatment of glenohumeral joint subluxation should be included in rehabilitation of hemiplegic patients. Comment by Miles Day, MD. The purpose of this study was to examine the relationship between shoulder subluxation in hemiplegic patients and reflex sympathetic dystrophy. They also examined if subluxation is associated with shoulder pain and the grade of subluxation in patients with subluxation and no reflex sympathetic dystrophy (RSD). Patients with injuries to the rotator cuff of the brachial plexus, marked spasticity, and major trauma to joint structures were excluded as these can be precipitating factors for RSD. The study noted a significantly higher presence of shoulder subluxation within the RSD group and the presence of pain was significantly high in patients with shoulder subluxation in the non-RSD group. The take home message of this article is that any measure or treatment that can be applied to the glenohumeral joint should be performed to eliminate the possibility of the patient developing RSD and subsequently hindering further rehabilitation in these patients. [source] Discal attachments of the human temporomandibular jointAUSTRALIAN DENTAL JOURNAL, Issue 3 2005JE Christo Abstract Background: Despite its clinical significance, the anatomy of the human temporomandibular joint (TMJ) and its relationship to the lateral pterygoid muscle remains poorly described and often misrepresented in standard texts. The aim of this study was to describe how the anterior and posterior attachments of the TMJ disc vary between lateral, central and medial regions of the joint. Methods: Ten left TMJs were removed en bloc from cadavers and serial sections were made at 3,4mm intervals. Observations were made to ascertain the anterior and posterior attachments of the disc and the joint structures were traced from standardized photographs. Results: Laterally, the capsule and lateral discal ligament merged prior to their attachment at the condylar pole. Medially, muscle fibres, capsule and the disc converged on the medial pole of the condyle. There was no evidence that fibres of the upper head of the lateral pterygoid muscle inserted directly into the disc. The upper head inserted into the condyle either directly at the pterygoid fovea or via a central tendon or indirectly via the capsule. Posteriorly, the superior part of the posterior attachment of the disc attached to the cartilaginous meatus and tympanic part of the temporal bone. The inferior part of the posterior attachment of the disc attached to the posterior surface of the condyle. In four joints, this attachment was folded beneath the posterior band of the disc, creating a wedge-shaped flap that ran medio-laterally. Conclusion: This study is in broad agreement with other anatomical TMJ studies but there are two main points of difference. Firstly, a true muscle insertion of the superior head of the lateral pterygoid muscle to the disc was not observed. Secondly, a wedge-shaped flap of retrodiscal tissue was identified between the condyle and the disc. [source] | ||||||||||