Hip Joint (hip + joint)

Distribution by Scientific Domains

Terms modified by Hip Joint

  • hip joint replacement

  • Selected Abstracts


    TETRAPLEGIA IN A PATIENT WITH HUGE HETEROTOPIC OSSIFICATION OF THE HIP JOINT AFTER TOTAL HIP ARTHROPLASTY: ADDITION OR REINFORCEMENT OF HANDICAPS

    JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 8 2003
    Satoshi Ishikawa MD
    No abstract is available for this article. [source]


    High-Turnover Periprosthetic Bone Remodeling and Immature Bone Formation Around Loose Cemented Total Hip Joints

    JOURNAL OF BONE AND MINERAL RESEARCH, Issue 1 2001
    Michiaki Takagi
    Abstract Aseptic loosening and periprosthetic osteolysis are the major problems awaiting solution in total hip surgery. The clinical investigation focused on the analysis of periprosthetic bone remodeling to clarify one important key event in the cascade of periprosthetic connective tissue weakening and osteolysis around loose artificial hip joints. Twelve acetabular bone samples adjacent to granulomatous synovial-like membrane of loose hip prosthesis were retrieved at revision surgery and processed for Villanueva bone staining for morphological observation and bone histomorphometric analysis. Eight well-fixed bony samples were used as control. Although osteoclastic surface and eroded surface by osteoclasts were evident in the periprosthetic bone from loose hip joints (p = 0.003 and p = 0.027), increased osteoid/low-mineralized bone matrix (p < 0.001) and osteoid width (p < 0.001) also were significant findings in structural analysis. In addition, not only elevated mineral apposition rate (MAR; p = 0.044) but also increased mineralizing surface (p = 0.044) and bone formation rate (BFR; p = 0.002) in loose periprosthetic bones were shown in dynamic data analysis. These results were confirmed by precise morphological observation by confocal laser scanning microscopy. Active coupling of bone formation and resorption and increased osteocytes with abundant bone canalicular projections were found in combined with the presence of immature bone matrices (osteoid and low-mineralized bone areas) in periprosthetic bones from loose hip joints. These results indicated that active osteoclastic bone resorption and/or defective bone formation are coupled with monocyte/macrophage-mediated foreign body-type granuloma in the synovial-like interface membrane of loose hip joints. Thus, this unique high-turnover periprosthetic bone remodeling with bad bone quality probably is caused by the result of cellular host response combined with inappropriate cyclic mechanical loading. The fragile periprosthetic bone may contribute to hip prosthesis loosening. [source]


    Wear Simulation of Alumina-on-Alumina Prosthetic Hip Joints Using a Multidirectional Motion Pin-on-Disk Device

    JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 11 2002
    Vesa Saikko
    The wear of a state-of-the-art implant alumina against itself was studied with a circularly translating pin-on-disk (CTPOD) device, a wear simulator for prosthetic hip joint materials. The direction of sliding changed continually relative to the pin, preventing erroneous uniaxial grooving typical of ordinary pin-on-disk devices. The dominating wear mechanism was mild abrasion manifested as a relieflike surface, which agreed with clinical findings. The wear factor ranged from 1 × 10,8 to 6 × 10,8 mm3/(N·m). The CTPOD device, validated earlier for ultrahigh molecular weight polyethylene, was shown to be the first simple wear test device to produce wear similar to that known to occur clinically in alumina-on-alumina total hip prostheses. [source]


    Rapidly destructive arthropathy of the hip in haemophilia

    HAEMOPHILIA, Issue 1 2001
    N. Ishiguro
    The aetiology of rapidly destructive arthropathy is still being debated. We report a 48-year-old male haemophiliac who exhibited hip arthropathy that was similar to rapidly destructive arthropathy. The hip joint was destroyed 6 months after the onset of symptoms. Results of clinical and laboratory examinations did not show any features of neuropathic, inflammatory or septic arthropathy, except for coagulopathy. Magnetic resonance imaging revealed an expansive joint capsule with synovial proliferation in the affected hip joint. Total hip arthroplasty was carried out successfully with total resection of the synovial tissue and joint capsule. A histological examination revealed bone necrosis, nonspecific inflammation, haemosiderosis and synovial hypertrophy. The recurrent bleeding into the hip joint induced pronounced inflammation with synovial proliferation and acute destruction of bony tissue. [source]


    Fibre type composition of the human psoas major muscle with regard to the level of its origin

    JOURNAL OF ANATOMY, Issue 6 2009
    Juraj Arbanas
    Abstract The aim of our study was to explore the fibre type composition of the human psoas major muscle at different levels of its origin, from the first lumbar to the fourth lumbar vertebra, and to compare the muscle fibre size and distribution of different fibre types between levels with respect to its complex postural and dynamic function. Muscle samples were collected from 15 young males (younger than 35 years). Serial transverse sections (5 ,m) of the samples were cut by cryomicrotome. Type I, IIA and IIX muscle fibres were typed using myosin heavy chain identification. The serial sections were analysed using a light microscope with a magnitude of 100×. The differences between measurements were evaluated using a repeated-measures anova and Scheffé test for post-hoc analysis. Our study showed that the human psoas major muscle was composed of type I, IIA and IIX muscle fibres. It had a predominance of type IIA muscle fibres, whereas type I muscle fibres had the largest cross-sectional area. Type IIX muscle fibres were present as a far smaller percentage and had the smallest cross-sectional area. Moreover, the fibre type composition of the psoas major muscle was different between levels of its origin starting from the first lumbar to the fourth lumbar vertebra. We conclude that the fibre type composition of the psoas major muscle indicated its dynamic and postural functions, which supports the fact that it is the main flexor of the hip joint (dynamic function) and stabilizer of the lumbar spine, sacroiliac and hip joints (postural function). The cranial part of the psoas major muscle has a primarily postural role, whereas the caudal part of the muscle has a dynamic role. [source]


    The hip joint: the fibrillar collagens associated with development and ageing in the rabbit

    JOURNAL OF ANATOMY, Issue 1 2001
    YVETTE S. BLAND
    The fibrillar collagens associated with the articular cartilages, joint capsule and ligamentum teres of the rabbit hip joint were characterised from the 17 d fetus to the 2-y-old adult by immunohistochemical methods. Initially the putative articular cartilage contains types I, III and V collagens, but when cavitation is complete in the 25 d fetus, type II collagen appears. In the 17 d fetus, the cells of the chondrogenous layers express type I collagen mRNA, but not that of type II collagen. Types III and V collagens are present throughout life, particularly pericellularly. Type I collagen is lost. In all respects, the articular cartilage of the hip joint is similar to that of the knee. The joint capsule contains types I, III and V collagens. In the fetus the ligamentum teres contains types I and V collagens and the cells express type I collagen mRNA; type III collagen is confined mainly to its surface and insertions. After birth, the same distribution remains, but there is more type III collagen in the ligament, proper. The attachment to the cartilage of the head of the femur is marked only by fibres of type I collagen traversing the cartilage; the attachment cannot be distinguished in preparations localising types III and V collagens. The attachment to the bone at the lip of the acetabulum is via fibres of types I and V collagens and little type III is present. The ligament is covered by a sheath of types III and V collagens. Type II collagen was not located in any part of the ligamentum teres. The distribution of collagens in the ligamentum teres is similar to that in the collateral ligaments of the knee. Its insertions are unusual because no fibrocartilage was detected. [source]


    Posaconazole as first line treatment for disseminated zygomycosis

    MYCOSES, Issue 6 2008
    Trisha Peel
    Summary We describe the first case report of posaconazole use as first line agent in the treatment of disseminated zygomycosis with prosthetic hip joint and pulmonary involvement due to Rhizopus microsporus. This infection occurred in a heavily immunosuppressed patient with systemic lupus erythematosus. [source]


    The Maka femur and its bearing on the antiquity of human walking: Applying contemporary concepts of morphogenesis to the human fossil record

    AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2002
    C. Owen Lovejoy
    Abstract MAK-VP-1/1, a proximal femur recovered from the Maka Sands (ca. 3.4 mya) of the Middle Awash, Ethiopia, and attributed to Australopithecus afarensis, is described in detail. It represents the oldest skeletal evidence of locomotion in this species, and is analyzed from a morphogenetic perspective. X-ray, CT, and metric data are evaluated, using a variety of methods including discriminant function. The specimen indicates that the hip joint of A. afarensis was remarkably like that of modern humans, and that the dramatic muscle allocation shifts which distinguish living humans and African apes were already present in a highly derived form in this species. Its anatomy provides no indication of any form of locomotion save habitual terrestrial bipedality, which very probably differed only trivially from that of modern humans. Am J Phys Anthropol 119:97,133, 2002. © 2002 Wiley-Liss, Inc. [source]


    Computer-aided navigation for arthroscopic hip surgery using encoder linkages for position tracking,

    THE INTERNATIONAL JOURNAL OF MEDICAL ROBOTICS AND COMPUTER ASSISTED SURGERY, Issue 3 2006
    Emily Monahan
    Abstract Background While arthroscopic surgery has many advantages over traditional surgery, this minimally invasive technique is not often applied to the hip joint. Two main reasons for this are the complexity of navigating within the joint and the difficulty of correctly placing portal incisions without damaging critical neurovascular structures. This paper proposes a computer-aided navigation system to address the challenges of arthroscopic hip surgery. Methods Unlike conventional arthroscopic methods, our system uses a hyper-redundant encoder linkage to track surgical instruments, thus eliminating the occlusion and distortion problems associated with standard optical and electromagnetic tracking systems. The encoder linkage position information is used to generate a computer display of patient anatomy. Results The tracking error from the encoder linkage was evaluated to be within an acceptable range for this tracking prototype, and the new computer-aided approach to arthroscopic hip surgery was applied to a prototype system for concept verification. Conclusion This navigation system for arthroscopic hip surgery can be used as a tool to address the challenges of joint navigation and portal placement in arthroscopic hip surgery by visually supplementing the limiting view from the arthroscope. The introduction of a tracking linkage shows significant potential as an alternative to other tracking systems. Positive feedback about the completed demo system was obtained from surgeons who perform arthroscopic proceduces. Copyright © 2006 John Wiley & Sons, Ltd. [source]


    Anatomy of the lateral femoral cutaneous nerve related to inguinal ligament, adjacent bony landmarks, and femoral artery

    CLINICAL ANATOMY, Issue 8 2008
    Porames Doklamyai
    Abstract Lateral femoral cutaneous nerve (LFCN) generally emerges from the pelvis behind the inguinal ligament (IL) to the thigh. Because of its proximity to the anterior superior iliac spine (ASIS) and hip joint, the LFCN is prone to injuries during various procedures. Anatomy of this nerve is highly variable among studies. Moreover, measurement data regarding its branches including the differences between genders and sides are still lacking. This study was, therefore, done to clarify these issues. Eighty-five thighs from 43 cadavers of both genders were dissected at the inguinal region. Distances from each branch of the LFCN to palpable landmarks: the ASIS, pubic tubercle (PT) and femoral artery (FA) were measured along the IL. Up to four branches of the LFCN were found; however, the single trunk was the most common form (>65%). The common site of this pattern on the IL was within 2 cm medial to the ASIS but could be present at over 6 cm. The distances in case of bifurcation were mostly comparable to those of the single trunk. In contrast, the values varied considerably in the cases with three or more branches (three cases). Regarding side and gender, asymmetry in the branching pattern was found in one fourth of specimens. However, only some minor differences between genders or sides in the measurement data were seen. These findings suggest that asymmetry and multiple branches of the LFCN should be concerned. The measurement data are also useful for localizing the LFCN with higher accuracy. Clin. Anat. 21:769,774, 2008. © 2008 Wiley-Liss, Inc. [source]


    Fibre type composition of the human psoas major muscle with regard to the level of its origin

    JOURNAL OF ANATOMY, Issue 6 2009
    Juraj Arbanas
    Abstract The aim of our study was to explore the fibre type composition of the human psoas major muscle at different levels of its origin, from the first lumbar to the fourth lumbar vertebra, and to compare the muscle fibre size and distribution of different fibre types between levels with respect to its complex postural and dynamic function. Muscle samples were collected from 15 young males (younger than 35 years). Serial transverse sections (5 ,m) of the samples were cut by cryomicrotome. Type I, IIA and IIX muscle fibres were typed using myosin heavy chain identification. The serial sections were analysed using a light microscope with a magnitude of 100×. The differences between measurements were evaluated using a repeated-measures anova and Scheffé test for post-hoc analysis. Our study showed that the human psoas major muscle was composed of type I, IIA and IIX muscle fibres. It had a predominance of type IIA muscle fibres, whereas type I muscle fibres had the largest cross-sectional area. Type IIX muscle fibres were present as a far smaller percentage and had the smallest cross-sectional area. Moreover, the fibre type composition of the psoas major muscle was different between levels of its origin starting from the first lumbar to the fourth lumbar vertebra. We conclude that the fibre type composition of the psoas major muscle indicated its dynamic and postural functions, which supports the fact that it is the main flexor of the hip joint (dynamic function) and stabilizer of the lumbar spine, sacroiliac and hip joints (postural function). The cranial part of the psoas major muscle has a primarily postural role, whereas the caudal part of the muscle has a dynamic role. [source]


    Estimation of heritability for hip dysplasia in German Shepherd Dogs in Finland

    JOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 2 2000
    M. Leppaänen
    The heritability of hip dysplasia in the German Shepherd Dog was estimated by applying the animal model and the Restricted Maximum Likelihood (REML) method to a data-set which consisted of the hip scores of 10 335 dogs. Fixed effects of the model were the month and the year of birth, screening age, the panelist responsible for screening and the origin of the animal's sire. The litter and the breeder had only minor effects on hip joints. Heritability estimates were moderate (0.31,0.35). The moderate heritability, which was found in this study, enables a much better genetic gain in the breeding programme, if proper evaluation methods, such as BLUP animal model, and effective selection is used instead of phenotypic selection. Zusammenfassung Schätzung der Heritabilität der Hüftgelenksdysplasie beim Deutschen Schäferhund in Finnland. Die Heritabilität der Hüftgelenksdysplasie beim Deutschen Schäferhund wurde mit Hilfe des Tiermodells und der Restricted Maximum Likelihood (REML) Methode anhand von Hüftgelenksgutachten von 10 335 Hunden geschätzt. Als fixe Effekte wurden im Modell ,Geburtsmonat' und ,-jahr', ,Röntgenalter', Einfluß des ,Gutachters' und ,Herkunft des Vaters' berücksichtigt. Die Effekte ,Wurf' und ,Züchter' hatten nur einen geringen Einfluß auf die Hüftgelenke. Die Heritabilitätsschätzungen betrugen 0.31 bis 0.35. Die in dieser Studie geschätzten Heritabilitäten ermöglichen es, zusammen mit geeigneten Methoden, wie beispielsweise dem BLUP-Tiermodell und einer effektiven Selektion, einen schnelleren Zuchtfortschritt zu erreichen, als nur phänotypisch zu selektieren. [source]


    Quantitative evaluation of the prosthetic head damage induced by microscopic third-body particles in total hip replacement

    JOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 4 2001
    Manuela Teresa Raimondi
    Abstract The increase of the femoral head roughness in artificial hip joints is strongly influenced by the presence of abrasive particulate entrapped between the articulating surfaces. The aim of the present study is to evaluate the dependence of such damage on the geometry of the particles entrapped in the joint, with reference to the UHMWPE/chrome-cobalt coupling. Five chrome-cobalt femoral heads and their coupled UHMWPE acetabular cups, retrieved at revision surgery after a short period of in situ functioning, have been investigated for the occurrence of third-body damage. This was found on all the prosthetic heads, where the peak-to-valley height of the scratches, as derived from profilometry evaluations, ranged from 0.3,1.3 ,m. The observed damage has been divided into four classes, related to the particle motion while being embedded into the polymer. Two kinds of particle morphology have been studied, spherical and prismatic, with size ranging from 5,50 ,m. In order to provide an estimation of the damage induced by such particles, a finite element model of the third-body interaction was set up. The peak-to-valley height of the impression due to the particle indentation on the chrome-cobalt surface is assumed as an index of the induced damage. The calculated values range from 0.1,0.5 ,m for spherical particles of size ranging from 10,40 ,m. In the case of prismatic particles, the peak-to-valley height can reach 1.3 ,m and depends both on the size and width of the particle's free corner, indenting the chrome-cobalt. As an example, a sharp-edged particle of size 30 ,m can induce on the chrome-cobalt an impression with peak-to-valley height of 0.75 ,m, when embedded into the polyethylene with a free edge of 5 ,m facing the metallic surface. Negligible damage is induced, if a free edge of 7.5 ,m is indenting the counterface. Our findings offer new support to the hypothesis that microscopic third-body particles are capable of causing increased roughening of the femoral head and provide a quantitative evaluation of the phenomenon. © 2001 John Wiley & Sons, Inc. J Biomed Mater Res (Appl Biomater) 58: 436,448, 2001 [source]


    High-Turnover Periprosthetic Bone Remodeling and Immature Bone Formation Around Loose Cemented Total Hip Joints

    JOURNAL OF BONE AND MINERAL RESEARCH, Issue 1 2001
    Michiaki Takagi
    Abstract Aseptic loosening and periprosthetic osteolysis are the major problems awaiting solution in total hip surgery. The clinical investigation focused on the analysis of periprosthetic bone remodeling to clarify one important key event in the cascade of periprosthetic connective tissue weakening and osteolysis around loose artificial hip joints. Twelve acetabular bone samples adjacent to granulomatous synovial-like membrane of loose hip prosthesis were retrieved at revision surgery and processed for Villanueva bone staining for morphological observation and bone histomorphometric analysis. Eight well-fixed bony samples were used as control. Although osteoclastic surface and eroded surface by osteoclasts were evident in the periprosthetic bone from loose hip joints (p = 0.003 and p = 0.027), increased osteoid/low-mineralized bone matrix (p < 0.001) and osteoid width (p < 0.001) also were significant findings in structural analysis. In addition, not only elevated mineral apposition rate (MAR; p = 0.044) but also increased mineralizing surface (p = 0.044) and bone formation rate (BFR; p = 0.002) in loose periprosthetic bones were shown in dynamic data analysis. These results were confirmed by precise morphological observation by confocal laser scanning microscopy. Active coupling of bone formation and resorption and increased osteocytes with abundant bone canalicular projections were found in combined with the presence of immature bone matrices (osteoid and low-mineralized bone areas) in periprosthetic bones from loose hip joints. These results indicated that active osteoclastic bone resorption and/or defective bone formation are coupled with monocyte/macrophage-mediated foreign body-type granuloma in the synovial-like interface membrane of loose hip joints. Thus, this unique high-turnover periprosthetic bone remodeling with bad bone quality probably is caused by the result of cellular host response combined with inappropriate cyclic mechanical loading. The fragile periprosthetic bone may contribute to hip prosthesis loosening. [source]


    Avoiding misclassification bias with the traditional Charnley classification: Rationale for a fourth Charnley class BB

    JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 9 2006
    C. Röder
    Abstract Long-term follow up of patients with total hip arthroplasty (THA) revealed a marked deterioration of walking capacities in Charnley class B after postoperative year 4. We hypothesized that a specific group of patients, namely those with unilateral hip arthroplasty and an untreated but affected contralateral hip was responsible for this observation. Therefore, we conducted a study taking into consideration the two subclasses that make up Charnley class B: patients with unilateral THA and contralateral hip disease and patients with bilateral THA. A sample of 15,160 patients with 35,773 follow ups that were prospectively collected over 10 years was evaluated. The sample was categorized into four classes according to a new modified Charnley classification. Annual analyses of the proportion of patients with ambulation longer than 60 min were conducted. The traditionally labeled Charnley class B consists of two very different patient groups with respect to their walking capacities. Those with unilateral THA and contralateral hip disease have underaverage walking capacities and a deterioration of ambulation beginning 3 to 4 years after surgery. Those with bilateral THA have stable overaverage walking capacities similar to Charnley class A. An extension of the traditional Charnley classification is proposed, taking into account the two different patient groups in Charnley class B. The new fourth Charnley class consists of patients with bilateral THA and was labeled BB in order to express the presence of two artificial hip joints and to preserve the traditional classification A through C. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res [source]


    THA loading arising from increased femoral anteversion and offset may lead to critical cement stresses

    JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2003
    Ralf U. Kleemann
    Abstract Aseptic loosening of artificial hip joints is believed to be influenced by the design and orientation of the implant. It is hypothesised that variations in implant anteversion and offset lead to changes in the loading of the proximal femur, causing critical conditions to both the bone and cement. The goal of this study was therefore to analyse the role of these parameters on loading, bone strains and cement stresses in total hip arthroplasty (THA). A validated musculo-skeletal model was used for the analysis of muscle and joint contact forces during walking and stair climbing. Two different anteversion angles (4° vs. 24°) and prostheses offsets (standard vs. long) were analysed. The loads for each case were applied to a cemented THA finite element model. Generally, stair climbing caused higher bone strains and cement stresses (max. +25%) than walking. Variations in anteversion and offset caused changes in the loading environment, bone strain distribution and cement stresses. Compared to the standard THA configuration, cement stresses were raised by increasing anteversion (max. +52%), offset (max. +5%) and their combination (max. +67%). Femoral anteversion, offset and their combination may therefore lead to an increased risk of implant loosening. Analyses of implant survival should consider this as a limiting factor in THA longevity. In clinical practice, implant orientation, especially in regard to pre- and post-operative anteversion, should be considered to be more critical. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source]


    Loss of cartilage structure, stiffness, and frictional properties in mice lacking PRG4

    ARTHRITIS & RHEUMATISM, Issue 6 2010
    Jeffrey 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]


    Developmental and osteoarthritic changes in Col6a1 -knockout mice: Biomechanics of type VI collagen in the cartilage pericellular matrix

    ARTHRITIS & RHEUMATISM, Issue 3 2009
    Leonidas G. Alexopoulos
    Objective Chondrocytes, the sole cell type in articular cartilage, maintain the extracellular matrix (ECM) through a homeostatic balance of anabolic and catabolic activities that are influenced by genetic factors, soluble mediators, and biophysical factors such as mechanical stress. Chondrocytes are encapsulated by a narrow tissue region termed the "pericellular matrix" (PCM), which in normal cartilage is defined by the exclusive presence of type VI collagen. Because the PCM completely surrounds each cell, it has been hypothesized that it serves as a filter or transducer for biochemical and/or biomechanical signals from the cartilage ECM. The present study was undertaken to investigate whether lack of type VI collagen may affect the development and biomechanical function of the PCM and alter the mechanical environment of chondrocytes during joint loading. Methods Col6a1,/, mice, which lack type VI collagen in their organs, were generated for use in these studies. At ages 1, 3, 6, and 11 months, bone mineral density (BMD) was measured, and osteoarthritic (OA) and developmental changes in the femoral head were evaluated histomorphometrically. Mechanical properties of articular cartilage from the hip joints of 1-month-old Col6a1,/,, Col6a1+/,, and Col6a1+/+ mice were assessed using an electromechanical test system, and mechanical properties of the PCM were measured using the micropipette aspiration technique. Results In Col6a1,/, and Col6a1+/, mice the PCM was structurally intact, but exhibited significantly reduced mechanical properties as compared with wild-type controls. With age, Col6a1,/, mice showed accelerated development of OA joint degeneration, as well as other musculoskeletal abnormalities such as delayed secondary ossification and reduced BMD. Conclusion These findings suggest that type VI collagen has an important role in regulating the physiology of the synovial joint and provide indirect evidence that alterations in the mechanical environment of chondrocytes, due to either loss of PCM properties or Col6a1,/, -derived joint laxity, can lead to progression of OA. [source]