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hip mechanics

Sylwia Szotek, Joanna Dawidowicz, Brian Eyden, Natalia Matysiak, Aleksander Czogalla, Grzegorz Dudzik, Anna Leśniewicz, Krzysztof Maksymowicz
Fascia lata is an important element of the fascial system, which forms the continuum of connective tissue throughout the body. This deep fascia envelops the entire thigh and hip area and its main function is to transmit mechanical forces generated by the musculoskeletal system of the lower extremities. Fascia lata is also known as a useful and easily harvested graft material. Despite its crucial role in lower extremity biomechanics and wide-ranging applications in plastic and reconstructive surgery, both the structure of fascia lata and particularly the cells populating this tissue are relatively unexplored and therefore poorly understood...
October 20, 2016: Ultrastructural Pathology
Marianne H Gillam, Nicole L Pratt, Maria C S Inacio, Elizabeth E Roughead, Sepehr Shakib, Stephen J Nicholls, Stephen E Graves
Background and purpose - It is unclear whether metal particles and ions produced by mechanical wear and corrosion of hip prostheses with metal-on-metal (MoM) bearings have systemic adverse effects on health. We compared the risk of heart failure in patients with conventional MoM total hip arthroplasty (THA) and in those with metal-on-polyethylene (MoP) THA. Patients and methods - We conducted a retrospective cohort study using data from the Australian Government Department of Veterans' Affairs health claims database on patients who received conventional THA for osteoarthritis between 2004 and 2012...
October 19, 2016: Acta Orthopaedica
Louis M Day, Subaraman Ramchandran, Cyrus M Jalai, Bassel G Diebo, Barthelemy Liabaud, Renaud Lafage, Themistocles Protopsaltis, Peter G Passias, Frank J Schwab, Shay Bess, Thomas J Errico, Virginie Lafage, Aaron J Buckland
STUDY DESIGN: Retrospective clinical and radiographic single-center study OBJECTIVE.: Assess simultaneous cervical spine and lower extremity compensatory changes with changes in thoracolumbar spinal alignment. SUMMARY OF BACKGROUND DATA: Full-body stereoradiographic imaging allows better understanding of reciprocal changes in cervical and lower extremity alignment in the setting of thoracolumbar malalignment. Few studies describe the simultaneous effect of alignment correction on these mechanisms...
October 17, 2016: Spine
Y K Liu, X X Deng, H L Yang
OBJECTIVES: The cytotoxicity induced by cobalt ions (Co(2+)) and cobalt nanoparticles (Co-NPs) which released following the insertion of a total hip prosthesis, has been reported. However, little is known about the underlying mechanisms. In this study, we investigate the toxic effect of Co(2+) and Co-NPs on liver cells, and explain further the potential mechanisms. METHODS: Co-NPs were characterised for size, shape, elemental analysis, and hydrodynamic diameter, and were assessed by Transmission Electron Microscope, Scanning Electron Microscope, Energy Dispersive X-ray Spectroscopy and Dynamic Light Scattering...
October 2016: Bone & Joint Research
Bhupinder Singh, Huy Vo, Shelby L Francis, Kathleen F Janz, John H Yack
PURPOSE: This study assessed the biomechanical gait changes in obese and normal weight female adult subjects following a commonly recommended 30-minute walking session. Hip and knee adduction and extensor moments, which are the primary modulators of frontal and sagittal plane load distribution were hypothesized to increase in obese females following a 30-minute walking period, resulting in more stress across the hip and knee joint. METHODS: Ten obese (37.7 ± 4...
October 6, 2016: Medicine and Science in Sports and Exercise
Atsushi Minatani, Kentaro Uchida, Gen Inoue, Shotaro Takano, Jun Aikawa, Masayuki Miyagi, Hisako Fujimaki, Dai Iwase, Kenji Onuma, Toshihide Matsumoto, Masashi Takaso
BACKGROUND: Calcitonin gene-related peptide (CGRP) is a 37-amino-acid vasodilatory neuropeptide that binds to receptor activity-modifying protein 1 (RAMP1) and the calcitonin receptor-like receptor (CLR). Clinical and preclinical evidence suggests that CGRP is associated with hip and knee joint pain; however, the regulation mechanisms of CGRP/CGRP receptor signaling in synovial tissue are not fully understood. METHODS: Synovial tissues were harvested from 43 participants with radiographic knee osteoarthritis (OA; unilateral Kellgren/Lawrence (K/L) grades 3-4) during total knee arthroplasty...
October 17, 2016: Journal of Orthopaedic Surgery and Research
Sherif Galal
: Developmental coxa vara (DCV) develops during early childhood between the age of independent walking and 6 years. The deformity includes a decrease in the neck-shaft angle and femoral retroversion. Recently, good results have been reported using external fixator systems for the correction of proximal femoral deformities secondary to slipped capital femoral epiphysis, Perthes' disease in children, and percutaneous proximal femoral osteotomy for coxa vara. This preliminary study was performed to evaluate the results of percutaneous subtrochanteric osteotomy in restoring the normal alignment and orientation (radiographic outcome), thereby restoring the normal mechanics of the hip joint, overcoming shortening of the limb, and re-establishing the length-tension relationship of the abductor muscles (functional outcome)...
September 29, 2016: Journal of Pediatric Orthopedics. Part B
E K Greska, N Cortes, S I Ringleb, J A Onate, B L Van Lunen
Previous studies have shown conflicting information regarding leg dominance as an etiological factor for the risk of anterior cruciate ligament (ACL) injuries. It remains unclear if lower extremity neuromechanical limb asymmetries exist in experienced athletes. The purpose of this study was to evaluate lower extremity neuromechanical effects of leg dominance in female collegiate soccer athletes during an unanticipated side-step cutting task. Twenty female collegiate soccer players completed an unanticipated side-step cutting task, using their dominant and non-dominant legs...
October 17, 2016: Scandinavian Journal of Medicine & Science in Sports
Vikesh V Chandaria, James McGinty, Niamh C Nowlan
Mechanical forces due to fetal movements play an important role in joint shape morphogenesis, and abnormalities of the joints relating to abnormal fetal movements can have long-term health implications. While mechanical stimulation during development has been shown to be important for joint shape, the relationship between the quantity of mechanical stimulation and the growth and shape change of developing cartilage has not been quantified. In this study, we culture embryonic chick limb explants in vitro in order to reveal how the magnitude of applied movement affects key aspects of the developing joint shape...
October 12, 2016: Journal of Biomechanics
Daniel S Hill, Kuntal Patel, Deepak Herlekar
BACKGROUND: Highly cross-linked polyethylene in total hip arthroplasty (THA) has been shown to decrease wear rate compared with a conventional polyethylene liner. However, it has also been reported that the manufacturing processes can cause early failure of the implant. CASE: We describe early catastrophic failure at <4 years following primary THA surgery of a PINNACLE MARATHON® polyethylene acetabular liner resulting from a malaligned PINNACLE DUOFIX HA® acetabular shell with resultant point loading...
October 13, 2016: Hip International: the Journal of Clinical and Experimental Research on Hip Pathology and Therapy
Azim Karim, Luis Pulido, Stephen Incavo
Accelerated physical therapy (PT) protocols are a potential mechanism for achieving early mobilization and safe discharge from hospital after elective primary total hip arthroplasty (THA) or total knee arthroplasty (TKA). We compared 2 groups of patients who underwent elective unilateral THA or TKA-those who started PT the same day (Day 0) and those who started PT the next day (Non-Day 0). The difference in mean (SD) hospital length of stay between the Day 0 and Non-Day 0 groups was not statistically significant for THA patients, 2...
September 2016: American Journal of Orthopedics
Armelle Perrichon, Bruno Reynard, Laurent Gremillard, Jérôme Chevalier, Frédéric Farizon, Jean Geringer
Ceramics are materials of choice for hip joint implants because of their excellent biocompatibility and mechanical properties. Wear of the bearing couple (femoral head and cup) remains one of the main concerns of hip implants. Although ceramics are known for their good tribological properties, shocks due to micro-separation, friction and hydrothermal ageing in physiological environment remain the three main sources of wear. It has been recently suggested that shock effects dominate but the three degradation mechanisms were so far simulated separately...
September 19, 2016: Journal of the Mechanical Behavior of Biomedical Materials
S Farmer, V V Shanbhogue, S Hansen, C I Stahlberg, H Vestergaard, A P Hermann, H Frederiksen
: In this cross-sectional study of 45 patients with myeloproliferative neoplasms, we found no evidence of secondary osteoporosis. INTRODUCTION: Patients with essential thrombocythemia (ET) and polycythaemia vera (PV) are at increased risk of fractures but the underlying mechanisms have not been settled. We conducted a study to assess bone mineral density, microarchitecture, estimated bone strength and global bone turnover in 45 patients with ET or PV. METHODS: Patients were evaluated in a cross-sectional study with dual energy X-ray absorptiometry (DXA) at the hip and spine; high-resolution peripheral quantitative computed tomography (HR-pQCT) at the distal radius and distal tibia; and biochemical markers of bone turnover including pro-collagen type 1 N-terminal pro-peptide, osteocalcin, C-terminal cross-linking telopeptide of type 1 collagen and bone-specific alkaline phosphatase...
October 13, 2016: Osteoporosis International
Outi Uimari, Juha Auvinen, Jari Jokelainen, Katri Puukka, Aimo Ruokonen, Marjo-Riitta Järvelin, Terhi Piltonen, Sirkka Keinänen-Kiukaanniemi, Krina Zondervan, Ilkka Järvelä, Markku Ryynänen, Hannu Martikainen
STUDY QUESTION: Are uterine fibroids associated with increased cardiovascular risk? SUMMARY ANSWER: This study reports an association between increased serum lipids and metabolic syndrome with an increased risk of uterine fibroids. WHAT IS KNOWN ALREADY: Recent studies suggest similarities in biological disease mechanisms and risk factors for fibroids and atherosclerosis: obesity, hypertension and abnormal serum lipids. These findings are awaiting confirmation that a population-based follow-up study could offer with extensive health examination data collection linked with a national hospital discharge register...
October 12, 2016: Human Reproduction
Michael A Samaan, Benedikt J Schwaiger, Matthew C Gallo, Thomas M Link, Alan L Zhang, Sharmila Majumdar, Richard B Souza
BACKGROUND: Femoroacetabular impingement (FAI) is a morphological abnormality of the hip joint that causes pain when performing a mechanically demanding activity of daily living such as the sit-to-stand (STS) task. Previous studies have assessed lower extremity joint mechanics during a STS task in various pathologies yet the STS task has not been studied in FAI patients. OBJECTIVE: To identify differences in joint kinetics and performance between FAI patients and healthy controls during a STS task...
October 8, 2016: PM & R: the Journal of Injury, Function, and Rehabilitation
Ran Schwarzkopf, Erik Schnaser, Taiki Nozaki, Yasuhito Kaneko, Michael J Gillman
INTRODUCTION: Patient-specific implants and instruments (PSI) have been used in both knee and shoulder replacements due to the perceived benefits of improved surgical accuracy and efficiency. The proposed benefits of using a PSI in total hip arthroplasty (THA) are numerous and include reduction of operative time and improved mechanical and anatomical alignment leading to increased implant longevity, increased stability, and clinical outcomes. We describe a novel patient-specific instrumentation and a surgical method that may improve directed resection of acetabular bone and accurate cup placement during THA...
October 6, 2016: Surgical Technology International
B Fink, R Lass
Background: Total hip arthroplasty (THA) is one of the most common and successful surgical procedures in orthopedic surgery and clinical success can be characterized by the revision rate and improvement of function, as well as the patient's satisfaction and pain. Despite the clinical success of primary THA with 10-year survival rates as high as 96 % (Swedish Hip Arthroplasty Register, 2011), the prevalence of groin pain after conventional total hip replacement ranges from 0.4 to 18.3 % and activity-limiting thigh pain is still an existing problem linked to the femoral component of uncemented hip replacement in up to 1...
October 2016: Zeitschrift Für Orthopädie und Unfallchirurgie
Marije Smit, Maureen J M Werner, Annemieke Oude Lansink-Hartgring, Willem Dieperink, Jan G Zijlstra, Matijs van Meurs
BACKGROUND: Intra-abdominal hypertension (IAH) is frequently present in critically ill patients and is an independent predictor for mortality. Better recognition of clinically important thresholds is necessary. Increased intra-abdominal pressure (IAP) is associated with renal dysfunction, and renal failure is one of the most consistently described organ dysfunctions associated with IAH. Obesity is also associated with kidney injury. The underlying mechanisms are not yet fully understood...
December 2016: Annals of Intensive Care
Ssu-Yu Chang, Yi-Jia Lin, Wei-Chun Hsu, Lin-Fen Hsieh, Yuan-Hsiang Lin, Chao-Chin Chang, You-Cai Chou, Li-Fei Chen
Six female patients with bilateral medial knee OA and 6 healthy controls were recruited. Patients with knee OA received a 6-week physiotherapist-supervised and home-based exercise program. Outcome measures, including the Western Ontario and McMaster Universities Arthritis Index and Short Form-36 Health Survey as well as objective biomechanical indices were obtained at baseline and follow-up. After treatment, no significant difference was observed in the knee abductor moment (KAM), lever arm, and ground reaction force...
2016: BioMed Research International
J Stone, S Aybek
Functional (psychogenic) limb weakness describes genuinely experienced limb power or paralysis in the absence of neurologic disease. The hallmark of functional limb weakness is the presence of internal inconsistency revealing a pattern of symptoms governed by abnormally focused attention. In this chapter we review the history and epidemiology of this clinical presentation as well as its subjective experience highlighting the detailed descriptions of authors at the end of the 19th and early 20th century. We discuss the relevance that physiological triggers such as injury and migraine and psychophysiological events such as panic and dissociation have to understanding of mechanism and treatment...
2017: Handbook of Clinical Neurology
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