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Altered lumbar spine structure, biochemistry, and biomechanical properties in a canine model of mucopolysaccharidosis type VIIEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The objective of this study was to examine potential associations between abnormal lumbar spine matrix structure and composition in MPS VII, and spine segment and tissue-level mechanical properties, using a naturally occurring canine model with a similar clinical phenotype to the human form of the disorder. Segments from juvenile MPS VII and unaffected dogs were allocated to: radiography, gross morphology, histology, biochemistry, and mechanical testing. MPS VII spines had radiolucent lesions in the vertebral body epiphyses. Histologically, this corresponded to a GAG-rich cartilaginous region in place of bone and elevated ...
Source: Journal of Orthopaedic Research - November 14, 2009 Category: Orthopaedics Authors: Lachlan J. Smith, John T. Martin, Spencer E. Szczesny, Katherine P. Ponder, Mark E. Haskins, Dawn M. Elliott Source Type: journals

Recombinant human bone morphogenetic protein-7 enhances fracture healing in an ischemic environmentEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In conclusion, our results indicate that rhBMP7 is a promising treatment for fractures with severely disrupted blood supply. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res (Source: Journal of Orthopaedic Research)
Source: Journal of Orthopaedic Research - November 13, 2009 Category: Orthopaedics Authors: Chuanyong Lu, Zhiqing Xing, Yan-yiu Yu, Celine Colnot, Theodore Miclau, Ralph S. Marcucio Source Type: journals

Influence of bone-derived matrices on generation of bone in an ectopic rat modelEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In conclusion, organic components of bone are needed for marrow-directed osteogenesis. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res (Source: Journal of Orthopaedic Research)
Source: Journal of Orthopaedic Research - November 13, 2009 Category: Orthopaedics Authors: H. Bahar, A. Yaffe, A. Boskey, I. Binderman Source Type: journals

Mechanobiological response of tendon stem cells: Implications of tendon homeostasis and pathogenesis of tendinopathyEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Tendons are constantly subjected to mechanical loading in vivo. Recently, stem cells were identified in human, mouse, and rabbit tendons, but the mechanobiological responses of tendon stem cells (TSCs) are still undefined. Using an in vitro system capable of mimicking in vivo loading conditions, it was determined that mechanical stretching increased TSC proliferation in a stretching magnitude-dependent manner. Moreover, low mechanical stretching at 4% ("clamp-to-clamp" engineering strain) promoted differentiation of TSCs into tenocytes, whereas large stretching at 8% induced differentiation of some TSCs into adipogenic, ch...
Source: Journal of Orthopaedic Research - November 13, 2009 Category: Orthopaedics Authors: Jianying Zhang, James H-C. Wang Source Type: journals

Lack of quadriceps dysfunction in women with early knee osteoarthritisEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Quadriceps dysfunction, specifically weakness and central activation failure (CAF), has been implicated in the development and progression of knee osteoarthritis (OA), though few data are available to confirm its presence in early OA. The purpose of this study was to determine the presence and magnitude of quadriceps dysfunction in those with and without early knee OA. Thirty-five female volunteers were classified into two groups, OA (n = 22) and control (n = 13), based on the presence [Kellgren-Lawrence (K-L) grade 2] or absence (K-L grade 0-1) of mild OA, respectively. Isometric quadriceps strength and central activation...
Source: Journal of Orthopaedic Research - November 13, 2009 Category: Orthopaedics Authors: Abbey C. Thomas, MaryFran Sowers, Carrie Karvonen-Gutierrez, Riann M. Palmieri-Smith Source Type: journals

Comparative study of carpal tunnel compliance in the human, dog, rabbit, and ratEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The purpose of this study was to measure the compliance of the carpal tunnel in candidate animal models of carpal tunnel syndrome (CTS), by measuring the resistance when passing a tapered metal rod through the carpal tunnel. Forepaws from 10 dogs, 10 rabbits, and 10 rats with intact carpal tunnels, and 10 fresh frozen human wrist cadavers were used. The slopes of the linear part of the force-displacement curve (a measure of stiffness), normal force, and increasing area ratio (InAR) were significantly different among the four species (p < 0.05). Post hoc analysis indicated that the mean slopes for the human carpal tunnel we...
Source: Journal of Orthopaedic Research - November 13, 2009 Category: Orthopaedics Authors: Wen-Lin Tung, Chunfeng Zhao, Yuichi Yoshii, Fong-Chin Su, Kin-Nan An, Peter C. Amadio Source Type: journals

Repair of large osteochondral defects in rabbits using porous hydroxyapatite/collagen (HAp/Col) and fibroblast growth factor-2 (FGF-2)Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This article reports the development of a porous hydroxyapatite/collagen (HAp/Col) scaffold as a bone void filler and a vehicle for drug administration. The scaffold consists of HAp nanocrystals and type I atelocollagen. The purpose of this study was to investigate the efficacy of porous HAp/Col impregnated with FGF-2 to repair large osteochondral defects in a rabbit model. Ninety-six cylindrical osteochondral defects 5 mm in diameter and 5 mm in depth were created in the femoral trochlear groove of the right knee. Animals were assigned to one of four treatment groups: porous HAp/Col impregnated with 50 µl of FGF-2 at a c...
Source: Journal of Orthopaedic Research - November 13, 2009 Category: Orthopaedics Authors: Hidetsugu Maehara, Shinichi Sotome, Toshitaka Yoshii, Ichiro Torigoe, Yuichi Kawasaki, Yumi Sugata, Masato Yuasa, Masahiro Hirano, Naomi Mochizuki, Masanori Kikuchi, Kenichi Shinomiya, Atsushi Okawa Source Type: journals

Engineering scaffold-free bone tissue using bone marrow stromal cell sheetsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The use of exogenous scaffolds to engineer bone tissue faces several drawbacks including insufficient biological activity, potential immunogenicity, elevated inflammatory reaction, fluctuating degradation rate, and low cell-attachment efficiency. To circumvent these limitations, we sought to engineer large scaffold-free bone tissue using cell sheets. We harvested intact cell sheets from bone marrow stromal cells using a continuous culture method and a scraping technique. The cell sheets were then rolled and fabricated into large constructs. Finally, the constructs were implanted into the subcutaneous pockets of nude mice. ...
Source: Journal of Orthopaedic Research - November 5, 2009 Category: Orthopaedics Authors: Dongyang Ma, Liling Ren, Yanpu Liu, Fulin Chen, Junrui Zhang, Zhenxun Xue, Tianqiu Mao Source Type: journals

Hyaluronic acid modulates gene expression of connective tissue growth factor (CTGF), transforming growth factor-[beta]1 (TGF-[beta]1), and vascular endothelial growth factor (VEGF) in human fibroblast-like synovial cells from advanced-stage osteoarthritis in vitroEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, after human synovial cells were stimulated with HA and Hylan (Synvisc®) for 24 h, real-time polymerase chain reaction (real-time PCR) was used to detect the alteration of connective tissue growth factor (CTGF), transforming growth factor-[beta]1 (TGF-[beta]1), and vascular endothelial growth factor (VEGF) gene expression, which were specific genes related to pathogenesis of OA knees. Our results illustrated that both HA and Hylan might not cause cytotoxicity or apoptosis of synovial cells in serum deprivation environment. The gene expressions of TGF-[beta]1 and VEGF were significantly increased at the conce...
Source: Journal of Orthopaedic Research - November 4, 2009 Category: Orthopaedics Authors: Yu-Tsang Lee, Hung-Jen Shao, Jyh-Horng Wang, Haw-Chang Liu, Sheng-Mou Hou, Tai-Horng Young Source Type: journals

The roles of TNFR1 in lipopolysaccharide-induced bone loss: Dual effects of TNFR1 on bone metabolism via osteoclastogenesis and osteoblast survivalEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In conclusion, RANK signaling plays a prominent role in osteoclastogenesis downstream of LPS. Furthermore, TNFR1 regulates bone metabolism through not only the regulation of osteoclast differentiation but also osteoblast survival. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res (Source: Journal of Orthopaedic Research)
Source: Journal of Orthopaedic Research - November 4, 2009 Category: Orthopaedics Authors: Hiroki Ochi, Yasushi Hara, Masahiro Tagawa, Kenichi Shinomiya, Yoshinari Asou Source Type: journals

Influence of the ratio of particulate autogenous bone graft/platelet-rich plasma on bone healing in critical-size defects: A histologic and histometric study in rat calvariaEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The purpose of this study was to analyze histomorphometrically the influence of the ratio of particulate autogenous bone (AB) graft/platelet-rich plasma (PRP) on bone healing in surgically created critical-size defects (CSD) in rat calvaria. Fifty rats were divided into five groups: Group C (control), Group AB, Group AB/PRP-50, Group AB/PRP-100, and Group AB/PRP-150. A 5-mm diameter critical-size defect was created in the calvarium of each animal. In Group C, the defect was filled by blood clot only. In Group AB, the defect was filled with 0.01 mL of AB graft. In Groups AB/PRP-50, AB/PRP-100, and AB/PRP-150, the defects we...
Source: Journal of Orthopaedic Research - November 4, 2009 Category: Orthopaedics Authors: Maria J. Nagata, Michel Messora, Natália Pola, Natália Campos, Rafael Vieira, Luis A. Esper, Michyele Sbrana, Stephen Fucini, Valdir Garcia, Alvaro Bosco Source Type: journals

Cyclic loading opens hemichannels to release ATP as part of a chondrocyte mechanotransduction pathwayEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In conclusion, mechanical loading triggers release of ATP via hemichannels. Hence, this study provides the first evidence of hemichannel involvement in chondrocyte mechanobiology. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res (Source: Journal of Orthopaedic Research)
Source: Journal of Orthopaedic Research - November 4, 2009 Category: Orthopaedics Authors: Mariana Garcia, Martin M. Knight Source Type: journals

Microcomputed tomography assessment of glenoid component cementation techniques in total shoulder arthroplastyEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Various strategies have been described to improve glenoid component cementation technique in shoulder arthroplasty, such as the "weephole" technique (WH), which is thought to allow for improved cement mantles by suction venting the glenoid vault through the coracoid. The purpose of this study was to compare the cement mantle created using standard syringe pressurization (SP) to WH or a new, modified weephole technique (MWH), not requiring specific instrumentation of the coracoid medullary canal. Fourteen cadaveric scapulae underwent preparation of the glenoid to allow for implantation of glenoid components. Component fixat...
Source: Journal of Orthopaedic Research - November 4, 2009 Category: Orthopaedics Authors: Syed Ashfaq Hasan, Wesley K. Cox, Muhammad Syed, Larry J. Suva Source Type: journals

The influence of muscle load on tibiofemoral knee kinematicsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A comparative kinematics study was conducted on six cadaver limbs, comparing tibiofemoral kinematics in five conditions: unloaded, under a constant 130 N ankle load with a variable quadriceps load, with and without a simultaneous constant 50 N medial and lateral hamstrings load. Kinematics were described as translation of the projected centers of the medial (MFT) and lateral femoral condyles (LFT) in the horizontal plane of the tibia, and tibial axial rotation (TR) as a function of flexion angle. In passive conditions, the tibia rotated internally with increasing flexion to an average of -16° (range: -12/-20°, SD = 3.0°...
Source: Journal of Orthopaedic Research - November 4, 2009 Category: Orthopaedics Authors: Jan Victor, Luc Labey, Pius Wong, Bernardo Innocenti, Johan Bellemans Source Type: journals

The effect of skeletal maturity on the regenerative function of intrinsic ACL cellsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, we hypothesized that fibroblastic cells from the ACLs of skeletally immature animals would proliferate and migrate more quickly than cells from adolescent and adult animals. ACL tissue from skeletally immature, adolescent, and adult pigs and sheep were obtained and cells obtained using explant culture. Cell proliferation within a collagen-platelet scaffold was measured at days 2, 7, and 14 of culture using AM MTT assay. Cellular migration was measured at 4 and 24 h using a modified Boyden chamber assay, and cell outgrowth from the explants also measured at 1 week. ACL cells from skeletally immature animals h...
Source: Journal of Orthopaedic Research - November 4, 2009 Category: Orthopaedics Authors: Ashley N. Mastrangelo, Elise M. Magarian, Matthew P. Palmer, Patrick Vavken, Martha M. Murray Source Type: journals

Effect of gradual weight-bearing on regenerated articular cartilage after joint distraction and motion in a rabbit modelEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The purpose of this study was to clarify the effect of gradual weight bearing (GWB) on regenerating cartilage. We developed a novel external fixation device (EFD) with a controllable weight-bearing system and continuous passive motion (CPM). A full-thickness defect was created by resection of the entire articular surface of the tibial plateau after the EFD was fixed in the rabbit's left knee. In the GWB group (n = 6), GWB was started 6 weeks after surgery. In the CPM group (n = 6), CPM with EFD was applied in the same manner without GWB. The control group (n = 5) received only joint distraction. All rabbits were sacrificed...
Source: Journal of Orthopaedic Research - November 4, 2009 Category: Orthopaedics Authors: Tomofumi Nishino, Tomoo Ishii, Fei Chang, Takaji Yanai, Arata Watanabe, Takeshi Ogawa, Hajime Mishima, Kenjiro Nakai, Naoyuki Ochiai Source Type: journals

Replacement of the medial tibial plateau by a metallic implant in a goat modelEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study shows that the medial tibial plateau can be successfully replaced by a cobalt-chromium implant in a large animal model. However, considerable femoral cartilage degeneration of the medial femoral condyle was induced, suggesting that care must be taken introducing hemiarthroplasty devices in a human clinical setting for the treatment of postmeniscectomy cartilage degeneration of the medial tibial plateau. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res (Source: Journal of Orthopaedic Research)
Source: Journal of Orthopaedic Research - November 3, 2009 Category: Orthopaedics Authors: Roel J.H. Custers, Daniel B.F. Saris, Laura B. Creemers, Ab J. Verbout, Mattie H.P. van Rijen, Simon C. Mastbergen, Floris P. Lafeber, Wouter J.A. Dhert Source Type: journals

Prolonged survival of experimental extremity allografts: A new protocol with total body irradiation, granulocyte-colony stimulation factor, and FK506Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, we investigated whether the timing of TBI influenced the period of graft survival. In total, 50 whole-limb allotransplants from LacZ transgenic rats to LEW rats were performed. TBI was performed at days 0 and 14, and G-CSF was given for 4 days after TBI. FK506 was given for 28 days after transplant. Nontreated limb allografts were rejected after 4.2 days. The survival time was prolonged to 64 days in the FK506 monotherapy group. In the group receiving TBI at day 14, limb allograft survival was significantly prolonged to 81 days. In the group receiving TBI at day 0, 26% of recipients died but in the surviving...
Source: Journal of Orthopaedic Research - October 30, 2009 Category: Orthopaedics Authors: Keiichi Muramatsu, Ryutaro Kuriyama, Hidetoyo Kato, Yuichiro Yoshida, Toshihiko Taguchi Source Type: journals

Altered expression of sodium channel distribution in the dorsal root ganglion after gradual elongation of rat sciatic nervesEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
To elucidate the pathophysiological mechanisms underlying chronic nerve-stretch injury, we gradually lengthened rat femurs by 15 mm at the rate of 0.5 mm/day (group L, n = 13). The control groups comprised sham-operated (group S, n = 10) and naive (group N, n = 8) rats. Immediately after the lengthening, we performed a conduction study on their sciatic nerves and harvested samples. Electrophysiological and histological analyses showed mild conduction slowing and axonal degeneration of unmyelinated fibers in group L rats. Altered mRNA expression of the voltage-gated sodium channels in the dorsal root ganglion was also obser...
Source: Journal of Orthopaedic Research - October 29, 2009 Category: Orthopaedics Authors: Katsunori Ohno, Atsushi Yokota, Shinji Hirofuji, Kiyoto Kanbara, Hisashi Ohtsuka, Mitsuo Kinoshita Source Type: journals

Acute repair of chondrocytes in the rabbit tibiofemoral joint following blunt impact using P188 surfactant and a preliminary investigation of its long-term efficacyEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Recent studies have indicated that there may be a correlation between acute chondrocyte damage and joint degeneration reminiscent of early-stage osteoarthritis (OA). P188 surfactant has been shown to acutely restore the integrity of damaged chondrocytes; however, its long-term efficacy is unknown. The hypothesis of this study was that a single injection of P188 into a traumatized joint would acutely repair damaged cell membranes and maintain their viability in the long term. Twelve rabbits were divided into two groups, with and without P188, and sacrificed 4 days after tibiofemoral (TF) impact. Another six rabbits were sac...
Source: Journal of Orthopaedic Research - October 29, 2009 Category: Orthopaedics Authors: Daniel I. Isaac, Nurit Golenberg, Roger C. Haut Source Type: journals

Wear mechanisms in metal-on-metal bearings: The importance of tribochemical reaction layersEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, we investigated the microstructural and chemical composition of the tribochemical reaction layers forming at the contacting surfaces of metallic bearings during sliding motion. Using X-ray photoelectron spectroscopy and transmission electron microscopy with coupled energy dispersive X-ray and electron energy loss spectroscopy, we found that the tribolayers are nanocrystalline in structure, and that they incorporate organic material stemming from the synovial fluid. This process, which has been termed "mechanical mixing," changes the bearing surface of the uppermost 50 to 200 nm from pure metallic to an organ...
Source: Journal of Orthopaedic Research - October 29, 2009 Category: Orthopaedics Authors: Markus A. Wimmer, Alfons Fischer, Robin Büscher, Robin Pourzal, Christoph Sprecher, Roland Hauert, Joshua J. Jacobs Source Type: journals

Effect of fracture gap on stability of compression plate fixation: A finite element studyEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In compression plating, anatomical reduction and compression across the fracture site are the basic principles necessary to achieve primary bone healing. However, varying amounts of gap at the fracture site frequently occur due to technical pitfalls, such as overbending of the plate and inaccurate reduction, and due to the fracture configuration itself. Little is known as to how fracture gap affects stability of the bone-plate construct. We analyzed the effects of fracture gap size (1 and 4 mm) and bone defect (25%, 50%, 75%, 100%) on the biomechanical stability of the compression plate-bone construct through validated fin...
Source: Journal of Orthopaedic Research - October 28, 2009 Category: Orthopaedics Authors: Jong-Keon Oh, Dipit Sahu, Yoon-Ho Ahn, Sung-Jae Lee, Sadami Tsutsumi, Jin-Ho Hwang, Duk-Young Jung, Stephan M. Perren, Chang-Wug Oh Source Type: journals

Nanostructure of collagen fibrils in human nucleus pulposus and its correlation with macroscale tissue mechanicsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Collagen fibrils are the main structural components of the nucleus pulposus tissue in the intervertebral discs. The structure-property relationship of the nucleus pulposus (NP) tissues is still unclear. We investigated the structure of individual collagen fibrils of the NP and evaluated its correlation with the bulk mechanical properties of the tissue. Collagen fibrils were extracted from the NP of discs retrieved from adolescents during scoliosis correction surgery, and the extracts were confirmed by SDS-PAGE. The diameters of the individual collagen fibrils were measured through atomic force microscopy, and the compressi...
Source: Journal of Orthopaedic Research - October 27, 2009 Category: Orthopaedics Authors: Darwesh M.K. Aladin, Kenneth M.C. Cheung, Alfonso H.W. Ngan, Danny Chan, Victor Y.L. Leung, Chwee Teck Lim, Keith D.K. Luk, William W. Lu Source Type: journals

A biodegradable scaffold for the treatment of a diaphyseal bone defect of the tibiaEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The aim of this study was to compare angiogenesis and osteogenesis occurring within 8.0 mm diaphyseal defects created in canine tibiae treated using autograft or a biodegradable bone scaffold. All tibiae were reamed to 7.0 mm and fixed with a 6.5-mm statically locked intramedullary nail. Each of the 18 canines as allotted to one of three treatment groups: (1) left empty (N = 5), (2) treated with iliac crest autograft (N = 6), or (3) treated with a PLGA/calcium phosphate biodegradable scaffold (N = 7). Fluorescent markers were given at successive time periods: calcein green at 6 weeks, xylenol orange at 9 weeks, and tetracy...
Source: Journal of Orthopaedic Research - October 27, 2009 Category: Orthopaedics Authors: Paul R.T. Kuzyk, Emil H. Schemitsch, John E. Davies Source Type: journals

Ibuprofen upregulates expressions of matrix metalloproteinase-1, -8, -9, and -13 without affecting expressions of types I and III collagen in tendon cellsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In conclusion, ibuprofen upregulates the expressions of collagenases including MMP-1, -8, -9, and -13 without affecting the expressions of types I and III collagen. These findings suggest a molecular mechanism potentially accounting for the inhibition of tendon healing by ibuprofen. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res (Source: Journal of Orthopaedic Research)
Source: Journal of Orthopaedic Research - October 21, 2009 Category: Orthopaedics Authors: Wen-Chung Tsai, Chih-Chin Hsu, Hsiang-Ning Chang, Yu-Chun Lin, Miao-Sui Lin, Jong-Hwei S. Pang Source Type: journals

Nanog maintains human chondrocyte phenotype and function in vitroEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Previous work showed that Nanog, a homeobox family transcription factor, maintains embryonic stem cell pluripotency, suggesting that it has a role in stabilizing cell phenotype. Human chondrocytes lose their phenotype and dedifferentiate after relatively few passages in culture, changes that may limit their value in restoring damaged articular cartilage. We hypothesized that Nanog could stabilize the phenotype of cultured human chondrocytes in long-term monolayer cultures. To test this hypothesis, the human Nanog gene was stably transduced into human chondrocytes using a retroviral vector. Chondrocyte-specific gene express...
Source: Journal of Orthopaedic Research - October 15, 2009 Category: Orthopaedics Authors: Hongjun Zheng, Francoise Gourronc, Joseph A. Buckwalter, James A. Martin Source Type: journals

Lymphocyte proliferation responses in patients with pseudotumors following metal-on-metal hip resurfacing arthroplastyEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Locally destructive soft tissue pseudotumor has been reported in patients following metal-on-metal hip resurfacing arthroplasty (MoMHRA). A delayed hypersensitivity reaction type IV to nickel (Ni), chromium (Cr), or cobalt (Co) has been suggested to play a role in its aetiology. The aim of this study was to investigate the incidence and level of metal-induced systemic hypersensitivity in patients with MoMHRA, both with and without pseudotumor by measuring lymphocyte proliferation responses to metals. A total of 92 patients were investigated: (1) MoMHRA patients with pseudotumors (nine female, one male); (2) MoMHRA patients...
Source: Journal of Orthopaedic Research - October 14, 2009 Category: Orthopaedics Authors: Young-Min Kwon, Peter Thomas, Burkhard Summer, Hemant Pandit, Adrian Taylor, David Beard, David W. Murray, Harinderjit S. Gill Source Type: journals

Optical coherence tomography grading correlates with MRI T2 mapping and extracellular matrix contentEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study tests the hypothesis that OCT correlates with magnetic resonance imaging (MRI) T2 values, and that OCT signal is sensitive to cartilage matrix degeneration. Forty-five osteochondral cores were harvested from five human tibial plateau explants after MRI T2 mapping. Cores underwent OCT imaging and were graded as follows: A, obvious birefringence; B, no birefringence; C, subsurface voids and/or irregular surface. Extracellular matrix content was determined and cores underwent histologic and polarized light microscopy (PLM) evaluation. Grade B and C cores had 25% higher superficial T2 values (p = 0.047) and 50% high...
Source: Journal of Orthopaedic Research - October 14, 2009 Category: Orthopaedics Authors: David M. Bear, Ashley Williams, Charleen T. Chu, Christian H. Coyle, Constance R. Chu Source Type: journals

Low affinity NGF receptor (p75 neurotrophin receptor) inhibitory antibody reduces pain behavior and CGRP expression in DRG in the mouse sciatic nerve crush modelEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Nerve growth factor (NGF) and its low-affinity receptor, p75 neurotrophin receptor (p75NTR), are important mediators of pain. To explore further the mechanisms involved, we examined suppression of pain behavior and expression of neuropeptides such as calcitonin gene-related peptide (CGRP) using a p75 NTR inhibitory antibody, in a mouse sciatic nerve crush model. In the nerve-injured model, 150 µg of a p75 NTR inhibitory antibody or 10 µl of saline were applied. The sciatic nerve in the sham-operated group was uninjured. Mechanical allodynia was measured for 2 weeks. CGRP and p75NTR expression in L5 dorsal root ganglions ...
Source: Journal of Orthopaedic Research - October 12, 2009 Category: Orthopaedics Authors: Yu Fukui, Seiji Ohtori, Masaomi Yamashita, Kazuyo Yamauchi, Gen Inoue, Munetaka Suzuki, Sumihisa Orita, Yawara Eguchi, Nobuyasu Ochiai, Shunji Kishida, Masashi Takaso, Ken Wakai, Yasushi Hayashi, Yasuchika Aoki, Kazuhisa Takahashi Source Type: journals

Promotion of bone formation by naringin in a titanium particle-induced diabetic murine calvarial osteolysis modelEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Diabetic patients have an increased risk of prosthesis failure requiring revision surgery. Furthermore, skeletal defects are observed in conjunction with type 1 diabetes. Using a titanium particle-induced calvarial osteolysis model in diabetic mice, we investigated the effect of diabetes on the osteolytic process and the role of naringin in its prevention. Three groups each of nondiabetic or diabetic mice were treated with vehicle only, with particles only, or with particles then naringin for 10 days. Alteration of bone indices near the midline suture were then analyzed by microcomputed tomography scanning and histology. S...
Source: Journal of Orthopaedic Research - October 11, 2009 Category: Orthopaedics Authors: Xiaoxiao Zhou, Peng Zhang, Chao Zhang, Zhen'an Zhu Source Type: journals

Effects of individual control of pH and hypoxia in chondrocyte cultureEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Effects of oxygen tension (pO2) and pH on gene and protein expression and metabolic activity of human chondrocytes were independently assessed. Chondrocytes were cultured under a range of pH (6.4-7.4) and different pO2 (5 and 20%) during 5 days in a bioreactor. Effects on gene expression, DNA content, protein expression, and metabolic activity were determined. Linear regression analysis showed that gene expression of type I collagen (COL1), SOX9, and VEGF is significantly lower at acidic pH, while expression of aggrecan, type II collagen, and HIF1A is pH-independent. Higher protein levels of VEGF were found under low pO2. ...
Source: Journal of Orthopaedic Research - October 7, 2009 Category: Orthopaedics Authors: R.H.J. Das, G.J.V.M. van Osch, M. Kreukniet, J. Oostra, H. Weinans, H. Jahr Source Type: journals

The role of muscle cells in regulating cartilage matrix productionEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Muscle is one of the tissues located in close proximity to cartilage tissue. Although it has been suggested that muscle could influence skeletal development through generating mechanical forces by means of contraction, very little is known regarding whether muscle cells release biochemical signals to regulate cartilage gene expression. We tested the hypothesis that muscle cells directly regulate cartilage matrix production by analyzing chondrocytes cocultured with muscle cells in 2D or 3D conditions. We found that chondrocytes cultured with C2C12 muscle cells exhibited enhanced alcian blue staining and elevated expression ...
Source: Journal of Orthopaedic Research - October 6, 2009 Category: Orthopaedics Authors: Dana M. Cairns, Philip G. Lee, Tomoya Uchimura, Christopher R. Seufert, Heenam Kwon, Li Zeng Source Type: journals

Synoviocytes are more sensitive than cartilage to the effects of minocycline and doxycycline on IL-1[alpha] and MMP-13-induced catabolic gene responsesEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The objective of this study was to determine the primary articular tissue target of doxycycline and minocycline. Synoviocytes - cartilage cocultures (n = 4) were treated with MMP-13 (25 ng/mL medium) or IL-1 (1.0 ng/mL medium) for 24 h. Doxycycline (4.3, 0.43, 0.043 µM) or minocycline (10, 1.0 or 0.1 µM) were then added and cultures were continued for 96 h. Cartilage and media were analyzed for GAG content. Quantitative PCR was used to measure cartilage MMP-3, MMP-13, aggrecan, COL2A1, ADAMTS-4, and ADAMTS-5 expression, and synoviocyte MMP-3, MMP-13, ADAMTS-4, and ADMATS-5 expression. Total and active MMP-3, MMP-13, and ...
Source: Journal of Orthopaedic Research - October 6, 2009 Category: Orthopaedics Authors: Lisa A. Fortier, Tatiana Motta, Robert A. Greenwald, Thomas J. Divers, Karen G. Mayr Source Type: journals

Effects of cyclic dynamic tensile strain on previously compressed inner annulus fibrosus and nucleus pulposus cells of human intervertebral disc - an in vitro studyEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Our objective was to investigate whether dynamic tensile strain on previously compressed human intervertebral disc (IVD) cells can restore the biosynthetic effects of collagen and glycosaminoglycan. Inner annulus fibrosus (AF) and nucleus pulposus (NP) tissues of adolescent idiopathic scoliosis cases undergoing thoracoscopic discectomy and fusion were cultured on compressive plates. Compressive stress was applied using 0.4 MPa at 1 Hz, for 2 h twice a day for 7 days, to the inner AF and NP tissues, followed by equibiaxial cyclic tensile strain to deform the released cells onto the plate's flexible bottom. With 10% elongati...
Source: Journal of Orthopaedic Research - October 6, 2009 Category: Orthopaedics Authors: Hwan Tak Hee, Jituan Zhang, Hee Kit Wong Source Type: journals

Titanium uptake, induction of RANK-L expression, and enhanced proliferation of human T-lymphocytesEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
There is increasing evidence that titanium ions are released from orthopedic implants by biocorrosion. The aim of this study was to investigate titanium uptake by human T-lymphocytes and its effects on phenotype and proliferation. Freshly isolated human nonadherent peripheral blood mononuclear cells (NA-PBMC), were exposed to TiCl4 [Ti(IV)]. Bioavailability and distribution of Ti(IV) in T-lymphocytes was determined by energy-filtered electron microscopy (EFTEM). The effects of Ti(IV) challenge on nonactivated and PHA-activated cells were assessed by flow cytometric analysis of surface markers, RANK-L production, and prolif...
Source: Journal of Orthopaedic Research - October 5, 2009 Category: Orthopaedics Authors: Dieter Cadosch, Michael Sutanto, Erwin Chan, Amir Mhawi, Oliver P. Gautschi, Brilliana von Katterfeld, Hans-Peter Simmen, Luis Filgueira Source Type: journals

Low-intensity pulsed ultrasound (LIPUS) increases the articular cartilage type II collagen in a rat osteoarthritis modelEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, the effect of low-intensity pulsed ultrasound (LIPUS) on cartilage was evaluated in a rat osteoarthritis (OA) model using serum biomarkers such as CTX-II (type II collagen degradation) and CPII (type II collagen synthesis) as well as histological criteria (Mankin score and immunohistochemical type II collagen staining). OA was surgically induced in the knee joint of rats by anterior cruciate/medial collateral ligament transection and medial meniscus resection (ACLT + MMx). Animals were divided into three groups: sham-operated group (Sham), ACLT + MMx group without LIPUS (-LIPUS), and ACLT + MMx group with LI...
Source: Journal of Orthopaedic Research - October 5, 2009 Category: Orthopaedics Authors: Kiyohito Naito, Taiji Watari, Tomoya Muta, Atsushi Furuhata, Hideaki Iwase, Mamoru Igarashi, Hisashi Kurosawa, Isao Nagaoka, Kazuo Kaneko Source Type: journals

Low-density lipoprotein receptor-related protein 5 (LRP5) expression in human osteoarthritic chondrocytesEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The aim of this study was to investigate the activation of the Wnt/[beta]-catenin pathway in osteoarthritis and the role of low-density lipoprotein receptor-related protein 5 (LRP5) in human osteoarthritic chondrocytes. The influence of 1,25(OH)2D3 on the expression of the LRP5 gene in human chondrocytes was also assessed. Human cartilage was obtained from 11 patients with primary osteoarthritis (OA) undergoing total knee replacement surgery. Normal cartilage was obtained from five healthy individuals. Beta-catenin and LRP5 mRNA levels were investigated using real-time PCR and LRP5 protein expression using Western blot ana...
Source: Journal of Orthopaedic Research - October 5, 2009 Category: Orthopaedics Authors: Ioanna Papathanasiou, Konstantinos N. Malizos, Aspasia Tsezou Source Type: journals

Influence of the growth factors PDGF-BB, TGF-[beta]1 and bFGF on the replicative aging of human articular chondrocytes during in vitro expansionEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Decreasing replicative potential and dedifferentiation of articular chondrocytes during expansion in cell culture are essential limitations for tissue engineering and cell therapy approaches. Telomeres and telomerase play a key role in cell development, aging, and tumorigenesis. There is evidence that growth factors are involved in regulating telomerase activity. Therefore, the objective was to evaluate the effect of selected growth factors on telomere biology of serially passaged chondrocytes. Human articular chondrocytes were isolated from cartilage of three patients undergoing total knee arthroplasty. The chondrocytes w...
Source: Journal of Orthopaedic Research - October 1, 2009 Category: Orthopaedics Authors: Anita Brandl, Peter Angele, Christina Roll, Lucas Prantl, Richard Kujat, Bernd Kinner Source Type: journals

New registration algorithm for determining 3D knee kinematics using CT and single-plane fluoroscopy with improved out-of-plane translation accuracyEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
To understand the kinematic effects of surgery, arthroplasty or conservative treatments, a noninvasive system to capture accurate 3D imaging of functional activities in prospective, controlled studies is required. To provide such a technique, a new algorithm was developed to register 3D CT data of normal bones to the same bones in a 2D fluoroscopy frame. The algorithm produces a digitally reconstructed radiograph (DRR) from the CT data and then filters this to produce an edge-enhanced image. The resulting image is then registered with an edge-enhanced version of the fluoroscopy frame using a new similarity measure called C...
Source: Journal of Orthopaedic Research - September 30, 2009 Category: Orthopaedics Authors: Jennifer M. Scarvell, Mark R. Pickering, Paul N. Smith Source Type: journals

Relationship between body habitus and joint leptin levels in a knee osteoarthritis populationEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Synovial fluid (SF) leptin has been shown to have an association with cartilage degeneration. Our objective was to examine the relationship between different measures of body habitus and SF leptin levels in an end-stage knee osteoarthritis (OA) population. Sixty consecutive patients with knee OA were surveyed prior to surgery for demographic data. Body habitus was assessed with the body mass index (BMI), waist circumference (WC), and waist-hip ratio (WHR). SF and serum samples were analyzed for leptin and adiponectin using specific ELISA. Nonparametric correlations and linear regression modeling was used to identify the re...
Source: Journal of Orthopaedic Research - September 24, 2009 Category: Orthopaedics Authors: Rajiv Gandhi, Mark Takahashi, Khalid Syed, J. Rod Davey, Nizar N. Mahomed Source Type: journals

Conditional deletion of BMP7 from the limb skeleton does not affect bone formation or fracture repairEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
While the osteoinductive activity of recombinant bone morphogenetic protein 7 (BMP7) is well established, evaluation of the role of endogenous BMP7 in bone formation and fracture healing has been hampered by perinatal lethality in BMP7 knockout mice. Here we employ conditional deletion of BMP7 from the embryonic limb prior to the onset of skeletogenesis to create limb bones lacking BMP7. We find that the absence of locally produced BMP7 has no effect on postnatal limb growth, articular cartilage formation, maintenance of bone mass, or fracture healing. Our data suggest that other BMPs present in adult bone are sufficient t...
Source: Journal of Orthopaedic Research - September 23, 2009 Category: Orthopaedics Authors: Kunikazu Tsuji, Karen Cox, Laura Gamer, Daniel Graf, Aris Economides, Vicki Rosen Source Type: journals

Stretch-induced inhibition of Wnt/[beta]-catenin signaling in mineralizing osteoblastsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Wnt signaling is important for bone formation and osteoblastic differentiation. Recent findings indicate a stimulating role of Wnt signaling in bone mechanotransduction. However, negative effects of Wnt signaling on osteoblast differentiation and mineralization have been described as well. We conducted in vitro stretch experiments using human pre-osteoblasts to study short- and long-term effects of mechanical loading on Wnt/[beta]-catenin signaling. As the extracellular regulated kinase (ERK) pathway is known to be involved in mechanotransduction in osteoblasts, we also evaluated its role in Wnt/[beta]-catenin signaling. S...
Source: Journal of Orthopaedic Research - September 23, 2009 Category: Orthopaedics Authors: Justus H.W. Jansen, Marco Eijken, Holger Jahr, Hideki Chiba, Jan A.N. Verhaar, Johannes P.T.M. van Leeuwen, Harrie Weinans Source Type: journals

Influence of age-related degeneration on regenerative potential of human nucleus pulposus cellsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Nucleus pulposus (NP) cells, sourced from herniation surgeries, may be used as a cell-based therapy for intervertebral disc (IVD) degeneration. But, both the regenerative potential of these degenerative adult NP cells and how to stimulate optimum matrix synthesis is not yet clear. The purpose of the current study was to understand the different phenotypic behaviors between degenerative adult NP cells and normal adolescent NP cells. Degenerative adult NP cells produced a significantly higher amount of proteoglycans and collagens than adolescent cells. Insulin-like growth factor-1 was the only anabolic cytokine with increase...
Source: Journal of Orthopaedic Research - September 23, 2009 Category: Orthopaedics Authors: Shu-Hua Yang, Chen-Chiang Lin, Ming-Hsiao Hu, Tiffany Ting-Fang Shih, Yuan-Hui Sun, Feng-Huei Lin Source Type: journals

Tendon-selective genes identified from rat and human musculoskeletal tissuesEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In conclusion, this study has defined a set of tendon-selective genes present in both adult rat and human tendons. Identification of tendon-selective genes provides potential molecular tools to facilitate a better understanding of tendon development and tendon repair. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res (Source: Journal of Orthopaedic Research)
Source: Journal of Orthopaedic Research - September 23, 2009 Category: Orthopaedics Authors: Scott A. Jelinsky, Joanne Archambault, Li Li, Howard Seeherman Source Type: journals

An internal locking plate to study intramembranous bone healing in a mouse femur fracture modelEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In most murine fracture models, the femur is stabilized by an intramedullary implant and heals predominantly through endochondral ossification. The aim of the present study was to establish a mouse model in which fractures heal intramembranously. Femur fractures of 16 SKH-mice were stabilized by an internal locking plate. Femur fractures of another 16 animals were stabilized by an intramedullary screw. Bone repair was analyzed by radiographic, biomechanical, and histological methods. At 2 weeks, histological analysis showed a significantly smaller callus diameter and callus area after locking plate fixation. Cartilage form...
Source: Journal of Orthopaedic Research - September 23, 2009 Category: Orthopaedics Authors: Tina Histing, Patric Garcia, Romano Matthys, Markus Leidinger, Joerg H. Holstein, Alexander Kristen, Tim Pohlemann, Michael D. Menger Source Type: journals

Novel Polysaccharide-derived hydrogel prevents perineural adhesions in a rat model of sciatic nerve adhesionEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We investigated the effects of a novel carboxymethylcellulose (CMC)-derived hydrogel, in which phosphatidylethanolamine (PE) was introduced into the carboxyl groups of CMC, for preventing perineural adhesion after extensive internal neurolysis of rat sciatic nerve. Sciatic nerves were randomly assigned to one of the following groups: the Control group, operated but no treatment; the HA group, operated and treated with 1% hyaluronan; the CMC-PE(L) group, operated and treated with low-viscosity CMC-PE hydrogel; and the CMC-PE(H) group, operated and treated with high-viscosity CMC-PE hydrogel. Perineural adhesions were evalua...
Source: Journal of Orthopaedic Research - September 23, 2009 Category: Orthopaedics Authors: Michiro Yamamoto, Nobuyuki Endo, Masaya Ito, Nobuyuki Okui, Shukuki Koh, Hiroaki Kaneko, Hitoshi Hirata Source Type: journals

Patellar tendon orientation and patellar tracking in male and female kneesEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Knowledge of patellofemoral joint biomechanics is important for understanding sex-related dimorphism in patellofemoral pathologies and advancement of related treatments. We evaluated the hypotheses that sex differences exist in patellar tendon (PT) orientation and patellar tracking during weight-bearing knee flexion and that they relate to differences in tibiofemoral rotation. The PT orientation and patellar tracking were measured in healthy subjects (18 male, 13 female) during weight-bearing knee flexion, using magnetic resonance and dual fluoroscopic imaging. These data were analyzed for sex differences and correlation w...
Source: Journal of Orthopaedic Research - September 23, 2009 Category: Orthopaedics Authors: Kartik M. Varadarajan, Thomas J. Gill, Andrew A. Freiberg, Harry E. Rubash, Guoan Li Source Type: journals

MMP-mediated collagen breakdown induced by activated protein C in equine cartilage is reduced by corticosteroidsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The plasma serine protease activated protein C (APC) is synthesized by human chondrocytes at sites of pathological cartilage fibrillation. APC levels are increased in osteoarthritis (OA) synovial fluid, and in vitro APC has been shown to synergize with interleukin-1[beta] (IL-1) to promote degradation from ovine cartilage. A model of equine cartilage degradation was established and used to explore corticosteroid activities. Intraarticular corticosteroids are a commonly prescribed treatment for joint disease, however their role in disease modification remains unclear. APC synergized with IL-1 or tumor necrosis factor-[alpha...
Source: Journal of Orthopaedic Research - September 22, 2009 Category: Orthopaedics Authors: Elaine R. Garvican, Anne Vaughan-Thomas, Colette Redmond, Natalie Gabriel, Peter D. Clegg Source Type: journals

Expression patterns of collagen types I and III in the capsule of a rat knee contracture modelEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Our objective was to determine the changes in expression of collagen types I and III in the capsule of a rat knee contracture model. The unilateral knee joints of adult male rats were rigidly immobilized at 150° of flexion using a rigid plastic plate and screws for 3 days, 1, 2, 4, 8, and 16 weeks (immobilized group). Sham-operated animals had holes drilled in the femur and tibia with screws inserted without a plate (control group). The expression patterns of collagen types I and III in the anterior and posterior capsule were evaluated by in situ hybridization (ISH), quantitative real-time polymerase chain reaction (qPCR)...
Source: Journal of Orthopaedic Research - September 22, 2009 Category: Orthopaedics Authors: Yoshihiro Hagiwara, Akira Ando, Yoshito Onoda, Hiroyuki Matsui, Eiichi Chimoto, Hideaki Suda, Eiji Itoi Source Type: journals

Dermal fibroblast-mediated BMP2 therapy to accelerate bone healing in an equine osteotomy modelEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study evaluated healing of equine metacarpal/metatarsal osteotomies in response to percutaneous injection of autologous dermal fibroblasts (DFbs) genetically engineered to secrete bone morphogenetic protein-2 (BMP2) or demonstrate green fluorescent protein (GFP) gene expression administered 14 days after surgery. Radiographic assessment of bone formation indicated greater and earlier healing of bone defects treated with DFb with BMP2 gene augmentation. Quantitative computed tomography and biomechanical testing revealed greater mineralized callus and torsional strength of DFb-BMP2-treated bone defects. On the histologi...
Source: Journal of Orthopaedic Research - September 22, 2009 Category: Orthopaedics Authors: Akikazu Ishihara, Lisa J. Zekas, Alan S. Litsky, Steven E. Weisbrode, Alicia L. Bertone Source Type: journals