Science.gov

Sample records for rabbit knees comparative

  1. Advantages of Pure Platelet-Rich Plasma Compared with Leukocyte- and Platelet-Rich Plasma in Treating Rabbit Knee Osteoarthritis.

    PubMed

    Yin, Wen-Jing; Xu, Hai-Tao; Sheng, Jia-Gen; An, Zhi-Quan; Guo, Shang-Chun; Xie, Xue-Tao; Zhang, Chang-Qing

    2016-04-17

    BACKGROUND Concentrated leukocytes in leukocyte- and platelet-rich plasma (L-PRP) may deliver increased levels of pro-inflammatory cytokines to activate the NF-κB signaling pathway, to counter the beneficial effects of growth factors on osteoarthritic cartilage. However, to date no relevant studies have substantiated that in vivo. MATERIAL AND METHODS Autologous L-PRP and pure platelet-rich plasma (P-PRP) were prepared, measured for componential composition, and injected intra-articularly after 4, 5, and 6 weeks post-anterior cruciate ligament transection. Caffeic acid phenethyl ester (CAPE) was injected intraperitoneally to inhibit NF-κB activation. All rabbits were sacrificed after 8 weeks postoperative. Enzyme-linked immunosorbent assays were performed to determine interleukin 1β (IL-1β) and prostaglandin E2 (PGE2) concentrations in the synovial fluid, Indian ink staining was performed for gross morphological assessment, and hematoxylin and eosin staining and toluidine blue staining were performed for histological assessment. RESULTS Compared with L-PRP, P-PRP injections achieved better outcomes regarding the prevention of cartilage destruction, preservation of cartilaginous matrix, and reduction of IL-1β and PGE2 concentrations. CAPE injections reversed the increased IL-1β and PGE2 concentrations in the synovial fluid after L-PRP injections and improved the outcome of L-PRP injections to a level similar to P-PRP injections, while they had no influence on the therapeutic efficacy of P-PRP injections. CONCLUSIONS Concentrated leukocytes in L-PRP may release increased levels of pro-inflammatory cytokines to activate the NF-κB signaling pathway, to counter the beneficial effects of growth factors on osteoarthritic cartilage, and finally, result in a inferior efficacy of L-PRP to P-PRP for the treatment of osteoarthritis.

  2. A new method to measure post-traumatic joint contractures in the rabbit knee.

    PubMed

    Hildebrand, Kevin A; Holmberg, Michael; Shrive, Nigel

    2003-12-01

    extension (flexion contracture) was demonstrated for the experimental knees using the new methodology where the maximum extension was 35 deg +/- 9 deg, compared to the unoperated knee maximum extension of 11 deg +/- 7 deg, 10 or 12 weeks after the immobilization was discontinued. The custom gripping device coupled to a materials testing machine will serve as a measurement test for future studies characterizing a rabbit knee model of post-traumatic joint contractures.

  3. Effects of estrogen deficiency and low bone mineral density on healthy knee cartilage in rabbits.

    PubMed

    Castañeda, Santos; Largo, Raquel; Calvo, Emilio; Bellido, Miriam; Gómez-Vaquero, Carmen; Herrero-Beaumont, Gabriel

    2010-06-01

    The purpose of this study was to compare the effects of estrogen deficiency and bone mass loss on normal knee cartilage in mature rabbits. Bilateral ovariectomy (OVX) was performed in 13 rabbits, 6 of which also received systemic glucocorticoid for 4 weeks. Seven additional healthy rabbits were used as controls. Bone mineral density (BMD) was measured by dual X-ray absorptiometry in lumbar spine, knee, and subchondral bone of the knee at baseline and 22 weeks after OVX. After sacrifice, the knees were dissected, macroscopy was assessed, and histological cartilage abnormalities were evaluated according to the Mankin score. Correlations of Mankin with BMD at different regions were also performed. When compared to baseline, differences in BMD were only found in spine and knee of the animals receiving glucocorticoids. All the animals subjected to OVX had a significantly higher Mankin score than controls. Mankin was upper in OVX animals receiving glucocorticoids, but differences were not significant. The Mankin score was inversely related with BMD in lumbar spine (r = -0.67; p < 0.01). Although low bone mineral density contributes to the minor osteoarthritic alterations observed in our model, estrogen deficiency itself seems to act directly to induce the main pathogenic effects in healthy cartilage of the rabbit.

  4. Intra-articular Duration of Durolane™ after Single Injection into the Rabbit Knee

    PubMed Central

    Edsman, Katarina; Hjelm, Roland; Lärkner, Helena; Nord, Lars I.; Karlsson, Anders; Wiebensjö, Åsa; Höglund, A. Urban; Kenne, Anne Helander; Näsström, Jacques

    2011-01-01

    Objective: The aim of the present study was to investigate the intra-articular duration of Durolane™ in a rabbit model to allow comparison between Durolane™ residence time and data reported for other hyaluronic acid products as well as native hyaluronic acid. Design: 14C-labeled Durolane™ was manufactured by labeling the cross-linker used for stabilization. A single injection of approximately 0.3 mL 14C-labeled Durolane™ was administered intra-articularly in both knee joints of male New Zealand White rabbits. At days 1, 2, 3, 7, 28, 60, 96, and 120 after injection, the knee joints of 4 animals were collected, and the radioactivity of the remaining gel was measured. The obtained data were fitted by exponential models to calculate the half-life of the gel. Two additional rabbits were used for histology of the joint 127 days after the injection. Results: The elimination of 14C-labeled Durolane™ followed first-order kinetics with an apparent half-life of approximately 32 days. Histology showed no morphological changes in the knee joints. Conclusions: This study shows that Durolane™ has a half-life of 32 days in the rabbit knee joint, which is much longer compared to literature data on hyaluronic acid and other modified hyaluronic acid products. PMID:26069596

  5. Rabbit knee model of post-traumatic joint contractures: the long-term natural history of motion loss and myofibroblasts.

    PubMed

    Hildebrand, Kevin A; Sutherland, Craig; Zhang, Mei

    2004-03-01

    Our objective is to describe the natural history of motion loss with time and myofibroblast numbers in a rabbit knee model of post-traumatic joint contractures. Twenty-eight skeletally mature New Zealand White female rabbits had five-mm-squares of cortical bone removed from the medial and lateral femoral condyles of the right knee. A Kirschner wire (K-wire) was used to immobilize the knee joint in maximum flexion. A second operation was performed 8 weeks later to remove the K-wire. The rabbits were divided into four groups depending on the time of remobilization; 0, 8, 16 or 32 weeks. The average flexion contracture of the experimental knees in the 0-week and 8-week remobilization groups (38 degrees and 33 degrees, respectively) were significantly greater when compared with the values of the unoperated contralateral knees (8 degrees). The average flexion contractures of the experimental knees in the 16-week and 32-week remobilization groups were also greater than the unoperated contralateral knees, although they were not statistically significant. The average flexion contractures of the 16-week and 32-week groups were 19 degrees and 18 degrees, respectively, indicating a stabilization of the motion loss. Myofibroblast numbers in the posterior joint capsules were elevated 4-5x in the knees with contractures when compared to the contralateral knees. The initial decrease in severity followed by stabilization of motion loss and the association of motion loss with myofibroblasts mimics the human scenario of permanent post-traumatic joint contractures.

  6. The ligaments and sesamoid bones of knee joint in New Zealand rabbits.

    PubMed

    Orhan, I O; Haziroglu, R M; Gultiken, M E

    2005-04-01

    This study has been conducted on the knee joints of the New Zealand rabbits. A total of 20 knee joints from 10 (five female, five male) adult New Zealand rabbits were studied in the study. Fourteen ligaments and four sesamoid bones including the patellar bone, the infrapatellar adipose body, and the suprapatellar cartilage specifically present in rabbits were grossly observed. The caudal meniscotibial ligaments of the lateral meniscus were noted to be lacking in these rabbits. Moreover, the medial collateral ligament did not have a capsular character in nature. Thus, adipose tissue was determined at a point where the suprapatellar cartilage and patella fused.

  7. Blocking of tumor necrosis factor activity promotes natural repair of osteochondral defects in rabbit knee

    PubMed Central

    2009-01-01

    Background and purpose Osteochondral defects have a limited capacity for repair. We therefore investigated the effects of tumor necrosis factor (TNF) signal blockade by etanercept (human recombinant soluble TNF receptor) on the repair of osteochondral defects in rabbit knees. Material and methods Osteochondral defects (5 mm in diameter) were created in the femoral patellar groove in rabbits. Soon after the procedure, a first subcutaneous injection of etanercept was performed. This single injection or, alternatively, 4 injections in total (twice a week for 2 weeks) were given. Each of these 2 groups was divided further into 3 subgroups: a low-dose group (0.05 μg/kg), an intermediate-dose group (0.4 μ g/kg), and a high-dose group (1.6 μ g /kg) with 19 rabbits in each. As a control, 19 rabbits were injected with water alone. The rabbits in each subgroup were killed 4 weeks (6 rabbits), 8 weeks (6 rabbits), or 24 weeks (7 rabbits) after surgery and repair was assessed histologically. Results Histological examination revealed that the natural process of repair of the osteochondral defects was promoted by 4 subcutaneous injections of intermediate-dose etanercept and by 1 or 4 injections of high-dose etanercept at the various time points examined postoperatively (4, 8, and 24 weeks). Western blot showed that rabbit TNFα had a high affinity for etanercept. Interpretation Blocking of TNF by etanercept enabled repair of osteochondral defects in rabbit knee. Anti-TNF therapy could be a strategy for the use of tissue engineering for bone and cartilage repair. PMID:19916697

  8. Magnetic resonance knee arthrography. Enhanced contrast by gadolinium complex in the rabbit and in humans.

    PubMed

    Engel, A

    1990-01-01

    This study contains the fundamentals and the technique of the intraarticular application of an MRI contrast agent in connection with magnetic resonance imaging (MRI arthrography). It also presents the resulting clinical relevance for knee joint diagnostics. The significance of MRI arthrography is linked above all to the central question of whether or not it is possible to depict the hyaline cartilage, its surface and its thickness with the help of MRI arthrography. MRI arthrography was used for in vitro examinations of rabbit knee joint cartilage and human joint cartilage. The in vivo application was carried out in 73 patients. Apart from the metric evaluation and the assessment of the information content of the MRI image, the corresponding histologic sections were made in 20 knee joints in order to compare the cartilage surface and the thickness of the cartilage with the results in the MRI image. The optimum amount of contrast agent for visualization was determined, the uptake and clearance of the contrast agent from the cartilage were assessed, and trace elements from the cartilage were also analyzed. The examination showed that the molecular structure of the contrast agent (gadolinium-DTPA) does not prevent the uptake of the contrast agent into the matrix of the hyaline cartilage. But this process is reversible. Thus, 14 hours after the intraarticular application of the contrast agent no measurable traces of gadolinium-DTPA could be established. The intraarticular application of the contrast agent also made it possible to achieve a constant and reproducible visualization of all joint structures. This affected mainly the surface of the hyaline cartilage. The best imaging quality was achieved with intraarticular application of 30 to 40 mL of a 2 mmolar solution of gadolinium-DTPA. The technique used for the intraarticular application is the same as for the common procedures of knee joint aspiration. The clinical importance of MRI arthrography lies in the fact that

  9. Elimination of tritium-labelled hyaluronic acid from normal and osteoarthritic rabbit knee joints.

    PubMed

    Lindenhayn, K; Heilmann, H H; Niederhausen, T; Walther, H U; Pohlenz, K

    1997-05-01

    The half-life of [3H]hyaluronic acid in rabbit knee joints was estimated using two methods: (i) by following the [3H]hyaluronan content of the synovial fluid after intra-articular injection and (ii) by following the 3H2O radioactivity of plasma after intra-articular injection of [3H]hyaluronan. For normal rabbits we obtained a half-life of 15.8 hours (method I) and 17.5 +/- 1.0 hours (mean +/- SEM, method II), respectively. The second method was used to estimate the kinetics of the hyaluronan elimination from normal, sham-operated, as well as from osteoarthritic rabbit knee joints (Colombo model of osteoarthritis). Four weeks after injury, during the developing phase of osteoarthritis, the half-life of hyaluronan rose significantly to 23.5 +/- 2.1 hours and returned to normal levels (17.4 +/- 2.7 hours) 12 weeks after the operation (osteoarthritis developed). At the stage of developed osteoarthritis, the clearance rates were considerably higher than in normal rabbits.

  10. A comparative evaluation of the Adaptive knee and Catech knee joints: a preliminary study.

    PubMed

    Jepson, F; Datta, D; Harris, I; Heller, B; Howitt, J; McLean, J

    2008-03-01

    The Adaptive knee joint is a microprocessor-controlled prosthetic knee that incorporates both pneumatic and hydraulic control in one electronic unit. Pneumatic control is said to provide control during swing phase and the hydraulic control during the stance phase of the gait. This hybrid controller is triggered by a computer contained within the knee that responds to input from force, time and angle sensors. The microprocessor then selects an appropriate speed and stability setting. The Catech knee joint is a conventional hydraulic knee joint. The aim of this study was to compare the Adaptive and Catech knee joints in established trans-femoral amputees. The patients meeting the inclusion criteria were all established trans-femoral amputees using the Catech knee joint. The study was carried out by performing gait analysis, assessing energy requirements using the Physiological Cost Index (PCI) and using questionnaires. There was no significant benefit gained from the use of the Adaptive knee over the Catech knee joint in our small study group.

  11. Periodic knee injections of collagen tripeptide delay cartilage degeneration in rabbit experimental osteoarthritis

    PubMed Central

    2013-01-01

    Introduction Collagen peptides have been reported to possess various biological activities for various cell types. The purposes of this study were, first, to examine the therapeutic effects of collagen tripeptide (Ctp) in rabbit osteoarthritis and, second, to explore a synergetic effect with hyaluronan (HA). Methods Osteoarthritis was induced by anterior cruciate ligament transection of the right knee in 72 Japanese white rabbits and they were divided into four groups (control, Ctp, HA and Ctp/HA). Each material was injected weekly into the knee, and knee joint samples were collected 5, 10 and 15 weeks after surgery. Macroscopic and histomorphological analyses of cartilage were conducted. Expression of type II collagen and matrix metalloproteinase-13 was also analyzed immunohistochemically. A Tukey's honestly significant difference test was used to evaluate the statistical significance of difference in the macroscopic, histological and immnohistochemical results. Results All treatment groups exhibited slightly higher resistance to the progression of osteoarthritis than the control group macroscopically 15 weeks after surgery. Histologically, intra-articular injection of Ctp significantly reduced cartilage degradation 10 weeks after surgery, and Ctp/HA significantly reduced it 5 weeks after surgery in comparison with the control. Immunohistochemically, both Ctp-treated and Ctp/HA-treated groups had significantly increased type II collagen-positive chondrocytes at the fifth week after the surgery, although the numbers of matrix metalloproteinase-13-positive chondrocytes were not affected. Conclusion Periodical injections of Ctp and Ctp/HA delayed progression of cartilage degeneration of early osteoarthritis induced by anterior cruciate ligament transection in rabbits. This effect appears to be exerted by promotion of type II collagen synthesis predominantly. PMID:23433227

  12. Comparative quantitative monitoring of rabbit haemorrhagic disease viruses in rabbit kittens

    PubMed Central

    2014-01-01

    Background Only one strain (the Czech CAPM-v351) of rabbit haemorrhagic disease virus (RHDV) has been released in Australia and New Zealand to control pest populations of the European rabbit O. cuniculus. Antigenic variants of RHDV known as RHDVa strains are reportedly replacing RHDV strains in other parts of the world, and Australia is currently investigating the usefulness of RHDVa to complement rabbit biocontrol efforts in Australia and New Zealand. RHDV efficiently kills adult rabbits but not rabbit kittens, which are more resistant to RHD the younger they are and which may carry the virus without signs of disease for prolonged periods. These different infection patterns in young rabbits may significantly influence RHDV epidemiology in the field and hence attempts to control rabbit numbers. Methods We quantified RHDV replication and shedding in 4–5 week old rabbits using quantitative real time PCR to assess their potential to shape RHDV epidemiology by shedding and transmitting virus. We further compared RHDV-v351 with an antigenic variant strain of RHDVa in kittens that is currently being considered as a potential RHDV strain for future release to improve rabbit biocontrol in Australia. Results Kittens were susceptible to infection with virus doses as low as 10 ID50. Virus growth, shedding and transmission after RHDVa infection was found to be comparable or non-significantly lower compared to RHDV. Virus replication and shedding was observed in all kittens infected, but was low in comparison to adult rabbits. Both viruses were shed and transmitted to bystander rabbits. While blood titres indicated that 4–5 week old kittens mostly clear the infection even in the absence of maternal antibodies, virus titres in liver, spleen and mesenteric lymph node were still high on day 5 post infection. Conclusions Rabbit kittens are susceptible to infection with very low doses of RHDV, and can transmit virus before they seroconvert. They may therefore play an important

  13. S53P4 bioactive glass and fibrin glue for the treatment of osteochondral lesions of the knee - a preliminary in vivo study in rabbits.

    PubMed

    Zazgyva, AncuŢa Marilena; Gurzu, Simona; Jung, Ioan; Nagy, Örs; Mühlfay, Gheorghe; Pop, Tudor Sorin

    2015-01-01

    The role of the subchondral bone and the importance of treating both bone and cartilage in cases of chondral and osteochondral lesions of the knee have been highly emphasized. There are no current studies on the experimental use of bioactive glass S53P4 (BonAlive®) as granules in the treatment of osteochondral lesions of the knee. Our preliminary study was designed to establish an experimental model and assesses the effect of glass granules fixed with fibrin compared to fibrin alone as fillers of the osteochondral defects created in the weight-bearing and partial weight-bearing regions of the distal femur in six adult rabbits. We found that the size of the distal femur in adult domestic rabbits allows the creation of 4 mm diameter and 5 mm deep osteochondral defects on both the medial femoral condyle and the trochlea, bilaterally, without significantly affecting the activity level of the animals. Retention of the glass granules in the defects was achieved successfully using a commercially available fibrin sealant. At five weeks post-implantation, we found macroscopic and microscopic differences between the four types of defects. The use of bioactive glass S53P4 for filling condylar osteochondral defects in rabbit femora led to the initiation of an early bone repair process, observed at five weeks after implantation, while the filling of trochlear defects with fibrin glue resulted in the appearance of cartilaginous tissue characteristic of endochondral ossification.

  14. A silk fibroin/chitosan scaffold in combination with bone marrow-derived mesenchymal stem cells to repair cartilage defects in the rabbit knee.

    PubMed

    Deng, Jiang; She, Rongfeng; Huang, Wenliang; Dong, Zhijun; Mo, Gang; Liu, Bin

    2013-08-01

    Bone marrow-derived mesenchymal stem cells (BMSCs) were seeded in a three-dimensional scaffold of silk fibroin (SF) and chitosan (CS) to repair cartilage defects in the rabbit knee. Totally 54 rabbits were randomly assigned to BMSCs + SF/CS scaffold, SF/CS scaffold and control groups. A cylindrical defect was created at the patellofemoral facet of the right knee of each rabbit and repaired by scaffold respectively. Samples were prepared at 4, 8 and 12 weeks post-surgery for gross observation, hematoxylin-eosin and toluidine blue staining, type II collagen immunohistochemistry, Wakitani histology. The results showed that differentiated BMSCs proliferated well in the scaffold. In the BMSCs + SF/CS scaffold group, the bone defect was nearly repaired, the scaffold was absorbed and immunohistochemistry was positive. In the SF/CS scaffold alone group, fiber-like tissues were observed, the scaffold was nearly degraded and immunohistochemistry was weakly positive. In the control group, the defect was not well repaired and positive immunoreactions were not detected. Modified Wakitani scores were superior in the BMSCs + SF/CS scaffold group compared with those in other groups at 4, 8 and 12 weeks (P < 0.05). A SF/CS scaffold can serve as carrier for stem cells to repair cartilage defects and may be used for cartilage tissue engineering.

  15. Histological study of effects of colloidal 90 yttrium on knee joint tissues of rabbits.

    PubMed

    Pavelka, K; Meier-Ruge, W; Müller, W; Fridrich, R

    1975-02-01

    The administration of 0-2-0-4 mCi 90 yttrium (90Y) into a normal rabbit knee joint fails to induce medical synovectomy and results in the proliferation of the synovialis. The synovial mesothelium shows early radiation damage but subsequently follows a restitution of the whole. Later (within 4 to 16 weeks) an extensive fibrosis of the stratum synovialis develops, as well as an occlusion and sclerosis of smaller synovial vessels and capillaries. These changes explain the beneficial therapeutic effect of 90Y in a chronic inflammatory joint effusion. After irradiation that joint cartilage shows an increased cellular proliferation of the superficial tangential cells and in the vicinity of the cruciate ligaments small foci of degenerated cartilage are present. The overall pattern of a joint treated with intra-articular 90Y corresponds to the histological pattern encountered regularly in joints of older people. Changes of the cartilage after the 90Y radiation could represent a factor predisposing the treated joint to a subsequent development of osteoarthrosis.

  16. Hard X-ray index of refraction tomography of a whole rabbit knee joint: A feasibility study.

    PubMed

    Gasilov, S; Mittone, A; Horng, A; Geith, T; Bravin, A; Baumbach, T; Coan, P

    2016-12-01

    We report results of the computed tomography reconstruction of the index of refraction in a whole rabbit knee joint examined at the photon energy of 51keV. Refraction based images make it possible to delineate the bone, cartilage, and soft tissues without adjusting the contrast window width and level. Density variations, which are related to tissue composition and are not visible in absorption X-ray images, are detected in the obtained refraction based images. We discuss why refraction-based images provide better detectability of low contrast features than absorption images.

  17. Comparative responsiveness of outcome measures for total knee arthroplasty

    PubMed Central

    Giesinger, K.; Hamilton, D.F.; Jost, B.; Holzner, B.; Giesinger, J.M.

    2014-01-01

    Summary Objective The aim of this study was to compare the responsiveness of various patient-reported outcome measures (PROMs) and clinician-reported outcomes following total knee arthroplasty (TKA) over a 2-year period. Methods Data were collected in a prospective cohort study of primary TKA. Patients who had completed Forgotten Joint Score-12 (FJS-12), Western Ontario and McMaster Universities (WOMAC) osteoarthritis (OA) index, EQ-5D, Knee Society Score and range of movement (ROM) assessment were included. Five time points were assessed: pre-operative, 2 months, 6 months, 1 year and 2 years post-operative. Results Data from 98 TKAs were available for analysis. Largest effect sizes (ES) for change from pre-operative to 2-month follow-up were observed for the Knee Society Score (KSS) Knee score (1.70) and WOMAC Total (−1.50). For the period from 6 months to 1 year the largest ES for change were shown by the FJS-12 (0.99) and the KSS Function Score (0.88). The EQ-5D showed the strongest ceiling effect at 1-year follow-up with 84.4% of patients scoring the maximum score. ES for the time from 1- to 2-year follow-up were largest for the FJS-12 (0.50). All other outcome measures showed ES equal or below 0.30. Conclusion Outcome measures differ considerably in responsiveness, especially beyond one year post-operatively. Joint-specific outcome measures are more responsive than clinician-reported or generic health outcome tools. The FJS-12 was the most responsive of the tools assessed; suggesting that joint awareness may be a more discerning measure of patient outcome than traditional PROMs. PMID:24262431

  18. Comparative Pharmacodynamics of Pancuronium, Cisatracurium, and CW002 in Rabbits

    PubMed Central

    Diaz, Leslie L; Zhang, Jingwei; Heerdt, Paul M

    2014-01-01

    Pancuronium is a long-duration neuromuscular blocking drug (NMBD) that has been used in anesthetized rabbits at 0.1 mg/kg. However, there are limited data regarding the time course for recovery from this dose either spontaneously or with pharmacologic reversal. Here we defined the potency, onset, and recovery characteristics for the intermediate-duration NMBD cisatracurium and CW002 (a novel cysteine-inactivated molecule) in the rabbit, and test the hypothesis that these drugs may be alternatives to 0.1 mg/kg pancuronium for survival procedures. New Zealand white rabbits anesthetized with isoflurane were studied in a cross-over design. Potencies of cisatracurium and CW002 were defined as the effective dose for 95% depression of evoked muscle twitch (ED95). Responses to 3×ED95 were used to define onset (time to maximal effect), recovery index (RI; time from 25% to 75% recovery of twitch), and duration (time to complete recovery). Responses to all drugs were determined with and without reversal by neostigmine–glycopyrrolate or l-cysteine. CW002 was 4-fold more potent than was cisatracurium, but their onset, RI, and duration were similar. Pancuronium had similar onset and RI but longer duration, compared with cisatracurium and CW002. Reversal shortened the recovery index and duration for all 3 drugs. At 3×ED95, cisatracurium and CW002 had the same onset as did standard-dose pancuronium, but durations were shorter and more predictable. In addition, CW002 can be reversed without the potential side effects of cholinergic manipulation. We conclude that cisatracurium and CW002 are viable alternatives to pancuronium for survival studies in rabbits. PMID:24827571

  19. Spatial variation in sympathetic influences on the vasculature of the synovium and medial collateral ligament of the rabbit knee joint.

    PubMed

    McDougall, J J; Ferrell, W R; Bray, R C

    1997-09-01

    1. Laser Doppler perfusion imaging was used to assess the role of the sympathetic nervous system in the control of blood flow to the medial collateral ligament and capsule (synovium and overlying fibrous tissues) of the rabbit knee joint. 2. Electrical stimulation of the saphenous nerve (width 1 ms; amplitude 20V; 1-30 Hz) produced a frequency-dependent vasoconstriction of knee joint vasculature. The response was maximal at 30 Hz and gave the greatest fall in perfusion at the femoral insertion of the ligament (by 33.8 +/- 7.4%, mean +/- S.E.M.; n = 5-6) and the smallest decrease at the tibial insertion of the ligament (by 10.6 +/- 2.9%). 3. Topical application of phentolamine (10(-6) mol) had no significant effect on basal knee joint blood flow. However, it abolished the nerve-mediated constrictor responses in all regions of the medial collateral ligament and synovium at all frequencies. 4. Topical administration of adrenaline (10(-14) to 10(-7) mol) caused a dose-dependent decrease in knee joint blood flow with the highest dose producing > 75% reduction in perfusion at all areas. 5. There was no evidence of a reactive hyperaemia in the 5 min following a 5 min period of femoral artery occlusion. Artificial manipulation of arterial blood pressure by intravenous infusion or withdrawal of blood caused a proportional change in ligament and synovial blood flow. These observations may indicate a lack of autoregulation in the joint and its exclusion from baroreflex modulation. 6. These results suggest a potential role for the sympathetic nervous system in the control of knee joint blood flow. Neuromodulation of ligament perfusion appears to predominate at the femoral insertion and this could prove to have functional significance.

  20. MRI and histologic analysis of collagen type II sponge on repairing the cartilage defects of rabbit knee joints.

    PubMed

    Chen, Honghui; Yang, Xiaohong; Liao, Yingyang; Zeng, Xuwen; Liang, Peihong; Kang, Ning; Tan, Jianrong; Liang, Zhiping

    2011-02-01

    There are limited treatment options for cartilage defects in clinical practice because of the lack of suitable biomaterials. Here, we evaluated the effects of collagen type II sponge on the articular cartilage repairing process using a cartilage injury of a rabbit knee joint model. We showed that the home-made collagen type II sponges appeared to have a suitable pore size of 93.26 ± 38.4 μm for chondrocyte growth. MRI with H&E staining results demonstrated that the effusion absorption in the collagen type II sponge treated group was quicker than that of the control group. Moreover, sporadic cartilage signals first appeared at 6 weeks in the collagen type II sponge treated group. Safranin O staining and immunohistochemical analysis confirmed that the newly formed cartilage expresses glycosaminoglycan and type II collagen matrix. Using Sirius red polarized light staining, we showed that the newly formed cartilage-like areas from the collagen type II treated group are significantly greater than those of the control group. Taken together, our data demonstrated that the home-made collagen type II sponge is able to promote cartilage repair in the cartilage injury of a rabbit knee joint model.

  1. Comparative observation of skeletal-dental abnormalities in wild, domestic, and laboratory rabbits.

    PubMed

    Okuda, Ayako; Hori, Yutaka; Ichihara, Nobutsune; Asari, Masao; Wiggs, Robert B

    2007-12-01

    Dietary habits must be considered as one of the major potential factors resulting in acquired malocclusions in rabbits. Although the dentition of the wild rabbit and the domesticated laboratory rabbit are basically identical, dietary habits are noticeably different. Therefore, the prevalence of tooth problems between these lagomorph species were investigated anatomically and radiographically. Mean measurements of the skull and dental arches suggested that wild rabbits have slightly shorter and wider skulls and dental arches compared with domestic laboratory rabbits. Root elongation of incisors and check teeth, and periodontal disease were more frequently observed in domestic laboratory rabbits. Diagnostic radiographs from domestic pet rabbits showed relatively higher crowns, severe root elongation, and advanced periodontitis. These results do not provide definitive evidence that dietary habits cause malocclusions, however they suggest that diet is a major factor in the initiation of malocclusions in rabbits.

  2. Preliminary histopathological study of intra-articular injection of a novel highly cross-linked hyaluronic acid in a rabbit model of knee osteoarthritis.

    PubMed

    Iannitti, Tommaso; Elhensheri, Mohamed; Bingöl, Ali O; Palmieri, Beniamino

    2013-04-01

    Osteoarthritis is a degenerative joint disease mostly occurring in the knee and commonly seen in middle-aged and elderly adults. Intra-articular injection of hyaluronic acid has been widely used for treatment of knee osteoarthritis. The aim of this study was to evaluate the efficacy of intra-articular injection of a novel highly cross-linked hyaluronic acid, alone or in combination with ropivacaine hydrochloride and triamcinolone acetonide, on knee articular cartilage in a rabbit model of collagenase-induced knee osteoarthritis. After induction of experimental osteoarthritis by intra-articular injection of collagenase, adult New Zealand white rabbits (n = 12) were divided into 3 groups. Group 1 (control group) received 0.3 ml phosphate buffered saline into the right knee joint. Group 2 received 0.3 ml cross-linked hyaluronic acid (33 mg/ml) into the right knee joint. Group 3 received a mixture of 0.15 ml cross-linked hyaluronic acid (33 mg/ml), 0.05 ml ropivacaine hydrochloride 1 % and 0.1 ml triamcinolone acetonide (10 mg/ml) into the right knee joint. Intra-articular injections were given 4 weeks after first collagenase injection and were administered once a week for 3 weeks. Gross pathology and histological evaluation of rabbits' knee joints were performed after 16 weeks following initial collagenase injection. Histological analysis of sections of right knee joints at lesion sites showed a significant decrease in Mankin's score in groups treated with hyaluronic acid alone or in combination with ropivacaine hydrochloride and triamcinolone acetonide versus control group (p < 0.05 and p < 0.01 respectively). This evidence was consistent with strong articular degenerative changes in control right knee joints (grade III osteoarthritis), while the treated groups revealed less severe articular degenerative changes (grade II osteoarthritis). The present results show that cross-linked hyaluronic acid, alone or in combination with ropivacaine hydrochloride and

  3. The effect of a cartilage bone marrow extract on experimentally induced osteoarthrosis in the knee joints of rabbits. A scanning electron microscopic study.

    PubMed

    Neumüller, J; Partsch, G; Adamiker, D; Eberl, R

    1981-03-01

    The development of osteoarthrosis following a partial meniscectomy on the knee cartilage of rabbits (Chinchilla hybrids) was monitored with a scanning electron microscope. Simultaneously, a study was made of the effect of the cartilage bone marrow extract Rumalon trademark on the development of the osteoarthrotic changes. Twelve days after the operation, osteoarthrotic changes were evident in the untreated operated joints. After 36 days the damage caused to the cartilage was already radical. The immobility of the operated joint also gave rise to obvious changes in the cartilage of the knee joints which had not undergone an operation. The irregular weight distribution due to the fixation of one joint was apparently enough to provoke degenerative processes on the other side. When the cartilage bone marrow extract Rumalon trademark was administered three times weekly (0.5 mg/kg body weight i.m.) a distinct retardation of the osteoarthrotic development in the early stages was observed. Where the changes had penetrated to the inner cartilage layers, no difference could be established compared to the untreated animals.

  4. Are static and dynamic kinematics comparable after total knee arthroplasty?

    PubMed

    Saevarsson, Stefan K; Romeo, Carolina I; Anglin, Carolyn

    2013-04-05

    Knee kinematics provide information about how the femoral, tibial and patellar bones or prosthetic components move relative to each other. Accurate knowledge of kinematics is valuable for implant design, comparisons between designs or surgical techniques, and to identify differences between patients with good and poor outcomes. Both static and dynamic imaging techniques have been used to evaluate kinematics. In general, static imaging is used to capture better quality images or to capture views that cannot be acquired by dynamic imaging, whereas dynamic imaging is used to capture real-life movements. How well static kinematics represent dynamic kinematics is subject to frequent debate and has not been adequately addressed, especially after total knee arthroplasty (TKA). We compared the static and dynamic weightbearing kinematics of 10 female subjects after TKA. Using the same clinical scanner for both methods, static images were taken using our standard protocol, sequential-biplane radiographs at multiple flexion angles, as well as with dynamic video fluoroscopy during a step up activity. The static method can reliably measure all 12 degrees of freedom (DOF) after TKA, however only seven were compared due to the poorer out-of-plane reliability in the single-plane dynamic imaging. No differences were found between the static and dynamic kinematics for nine out of ten subjects. For one subject, however, a difference of 5-8° in internal/external tibial rotation was found. The research question, study purpose and the advantages and disadvantages of each method need to be considered when determining which imaging method to use.

  5. Simultaneous dual frequency 1H and 19F open coil imaging of arthritic rabbit knee at 3T.

    PubMed

    Hockett, Franklin D; Wallace, Kirk D; Schmieder, Anne H; Caruthers, Shelton D; Pham, Christine T N; Wickline, Samuel A; Lanza, Gregory M

    2011-01-01

    The combination of sensitive magnetic resonance techniques with a selective site-targeted nanoparticle contrast agent has a demonstrated utility for molecular imaging studies. By detecting a unique signature of the contrast agent, this approach can be employed to identify specific bio-molecular markers and observe cellular-level processes within a large and complex organism (e.g., in vivo rabbit). The objective of the present investigation was to design, fabricate and characterize a radio-frequency (RF) coil for the dual frequency ((1)H and (19)F) simultaneous collection of both nuclei images in a 3T field, in order to facilitate studies of arthritic knee degradation in rabbits. The coil supports both transmit and receive modes. The supporting activities included: 1) establishing a technical database for calculating the required coil parameters, 2) selection of a favorable coil geometry, and 3) adaption of existing RF measurement techniques to the design, development and electrical evaluation of the coil. The coil is used in conjunction with a Philips Medical Systems clinical MRI scanner, requiring all RF simultaneous dual frequency ((1)H and (19)F) coils to operate in both transmit and receive modes. A commercial version of SPICE (simulation program with integrated circuit emphasis) was used to estimate significant operational parameters prior to fabricating the imaging coil. Excellent images were obtained with the fabricated coil and no operational problems were observed that would limit the use of other coil geometries and field strengths.

  6. Early outcomes of twin-peg mobile-bearing unicompartmental knee arthroplasty compared with primary total knee arthroplasty

    PubMed Central

    Lum, Z. C.; Lombardi, A. V.; Hurst, J. M.; Morris, M. J.; Adams, J. B.; Berend, K. R.

    2016-01-01

    Aims Since redesign of the Oxford phase III mobile-bearing unicompartmental knee arthroplasty (UKA) femoral component to a twin-peg design, there has not been a direct comparison to total knee arthroplasty (TKA). Thus, we explored differences between the two cohorts. Patients and Methods A total of 168 patients (201 knees) underwent medial UKA with the Oxford Partial Knee Twin-Peg. These patients were compared with a randomly selected group of 177 patients (189 knees) with primary Vanguard TKA. Patient demographics, Knee Society (KS) scores and range of movement (ROM) were compared between the two cohorts. Additionally, revision, re-operation and manipulation under anaesthesia rates were analysed. Results The mean follow-up for UKA and TKA groups was 5.4 and 5.5 years, respectively. Six TKA (3.2%) versus three UKAs (1.5%) were revised which was not significant (p = 0.269). Manipulation was more frequent after TKA (16; 8.5%) versus none in the UKA group (p < 0.001). UKA patients had higher post-operative KS function scores versus TKA patients (78 versus 66, p < 0.001) with a trend toward greater improvement, but there was no difference in ROM and KS clinical improvement (p = 0.382 and 0.420, respectively). Conclusion We found fewer manipulations, and higher functional outcomes for patients treated with medial mobile-bearing UKA compared with TKA. TKA had twice the revision rate as UKA although this did not reach statistical significance with the numbers available. Cite this article: Bone Joint J 2016;98-B(10 Suppl B):28–33. PMID:27694513

  7. Effects of Platelet-Rich Plasma & Platelet-Rich Fibrin with and without Stromal Cell-Derived Factor-1 on Repairing Full-Thickness Cartilage Defects in Knees of Rabbits

    PubMed Central

    Bahmanpour, Soghra; Ghasemi, Maryam; Sadeghi-Naini, Mohsen; Kashani, Iraj Ragerdi

    2016-01-01

    Background: The purpose of this study was to create biomaterial scaffolds like platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) containing stromal cell-derived factor-1 (SDF1) as a chemokine to induce hyaline cartilage regeneration of rabbit knee in a full thickness defect. Methods: We created a full thickness defect in the trochlear groove of thirty-six bilateral knees of eighteen mature male rabbits. The knees were randomly divided into six groups (group I: untreated control, group II: PRP, group III: PRF, group IV: Gelatin+SDF1, group V: PRP+SDF1, and group VI: PRF+SDF1). After four weeks, the tissue specimens were evaluated by macroscopic examination and histological grading, immunofluorescent staining for collagen type II, and analyzed for cartilage marker genes by real-time PCR. The data were compared using statistical methods (SPSS 20, Kruskal-Wallis test, Bonferroni post hoc test and P<0.05). Results: Macroscopic evaluations revealed that international cartilage repair society (ICRS) scores of the PRF+SDF1 group were higher than other groups. Microscopic analysis showed that the ICRS score of the PRP group was significantly lower than other groups. Immunofluorescent staining for collagen II demonstrated a remarkable distribution of type II collagen in the Gel+SDF1, PRP+SDF1 and PRF+SDF1 groups compared with other groups. Real-time PCR analysis revealed that mRNA expression of SOX9 and aggrecan were significantly greater in the PRF+SDF1, PRP+SDF1, Gel+SDF1 and PRF groups than the control group (P<0.05). Conclusion: Our results indicate that implantation of PRF scaffold containing SDF1 led to the greatest evaluation scores of full-thickness lesions in rabbits. PMID:27853331

  8. Multidimensional visualization of healthy and sensitized rabbit knee tissues by means of confocal microscopy

    NASA Astrophysics Data System (ADS)

    Rudys, Romualdas; Bagdonas, Saulius; Kirdaitė, Gailutė; Papečkienė, Jurga; Rotomskis, Ričardas

    2015-05-01

    This study combines several fluorescence detection methods to distinguish structural features of the synovium and cartilage tissues and to visualize the localization of endogenous porphyrins in the sensitized tissues. Specimens of synovium and cartilage tissues obtained from rabbits with antigen-induced monoarthritis after intra-articular 5-aminolevulinic acid methyl ester injection and those from healthy rabbits were investigated ex vivo by means of fluorescence spectroscopy, fluorescence intensity, and lifetime microscopy. The presence of endogenous porphyrins was confirmed with the fluorescence spectra measured on sliced sensitized specimens. Application of the lifetime-gating method on fast fluorescence lifetime imaging microscopy images, allowed separate visualization of tissue structures possessing different average lifetimes. The presence of the structures has been validated by histopathological imaging based on conventional rapid hematoxylin-eosin staining of the specimens. The fluorescence lifetime of endogenous protoporphyrin IX has been assessed and employed for visualization of sensitized tissues.

  9. Influence of Knee Immobilization on Chondrocyte Apoptosis and Histological Features of the Anterior Cruciate Ligament Insertion and Articular Cartilage in Rabbits

    PubMed Central

    Mutsuzaki, Hirotaka; Nakajima, Hiromi; Wadano, Yasuyoshi; Furuhata, Syogo; Sakane, Masataka

    2017-01-01

    This study examined the influence of immobilization on chondrocyte apoptosis and histological features of the anterior cruciate ligament (ACL) insertion and knee articular cartilage in rabbits. Forty-eight male Japanese white rabbits were assigned to an immobilization (n = 24) or sham (n = 24) group. Rabbits in the immobilization group underwent complete unilateral surgical knee immobilization and rabbits in the sham group underwent a sham surgery. The average thickness of the glycosaminoglycan (GAG) stained red area by safranin O staining, the chondrocyte apoptosis rate and the chondrocyte proliferation rate in the cartilage layer in the ACL insertion and the articular cartilage of the medial tibial condyle were measured at one, two, four and eight weeks in six animals from each group. In the ACL insertion, the chondrocyte apoptosis rate was higher in the immobilization group than in the sham group at two and eight weeks after surgery (p < 0.05). The chondrocyte proliferation rate gradually decreased from two weeks to eight weeks in the immobilization group. The GAG layer was thinner in the immobilization group than in the sham group at two, four and eight weeks after surgery (p < 0.05). In the articular cartilage, the chondrocyte apoptosis rate in the immobilization group was higher than in the sham group at four and eight weeks after surgery (p < 0.05). The GAG layer was significantly thinner in the immobilization group than that in the sham group at four and eight weeks after surgery (p < 0.05). Knee immobilization significantly increased chondrocyte apoptosis at two and eight weeks after surgery in the ACL insertion and at four and eight weeks after surgery in the articular cartilage of the medial tibial condyle, and decreased GAG layer thickness from two to eight weeks after surgery in the ACL insertion and from four to eight weeks after surgery in the articular cartilage. PMID:28134763

  10. A comparative assessment of alternatives to the full-leg radiograph for determining knee joint alignment

    PubMed Central

    2012-01-01

    Background The purpose of this study was to assess the concurrent validity of alternative measures of frontal plane knee alignment, namely the radiographic anatomic axis and two clinical measures in patients complaining of knee malalignment as compared with the mechanical axis on full-length radiograph of lower limbs. Methods The knee-alignment angle was measured in 100 knees of 50 subjects with the chief complaint of frontal knee malalignment according to the following methods: lower-limb mechanical axis on radiograph, lower-limb anatomic axis on radiograph, distance between medial femoral condyles or medial malleoli using a calliper and lower-limb alignment using a goniometer. Data were analyzed using Pearson’s correlation coefficient and simple linear regression. Results The anatomic axis best correlated with the mechanical axis (r = 0.93, P<0.001), followed closely by the intercondylar/intermalleolar distance measured by calliper (r = 0.89, P<0.001). Significant correlation was also found between the mechanical-axis angle and the lower limb axis measured by goniometer (r = 0.67, P<0.001). Conclusions The anatomic axis on radiograph, the calliper method and to a lesser extent the goniometer measurement appear to be valid alternatives to the mechanical axis on full-leg radiograph for determining frontal plane knee alignment. These alternative measures have the potential to provide useful information regarding knee alignment and may increase the assessment of this parameter by clinicians and researchers. PMID:23110745

  11. In vivo prompt gamma neutron activation analysis for the screening of boron-10 distribution in a rabbit knee: a simulation study

    NASA Astrophysics Data System (ADS)

    Zhu, X.; Clackdoyle, R.; Shortkroff, S.; Yanch, J.

    2008-05-01

    Boron neutron capture synovectomy (BNCS) is under development as a potential treatment modality for rheumatoid arthritis (RA). RA is characterized by the inflammation of the synovium (the membrane lining articular joints), which leads to pain and a restricted range of motion. BNCS is a two-part procedure involving the injection of a boronated compound directly into the diseased joint followed by irradiation with a low-energy neutron beam. The neutron capture reactions taking place in the synovium deliver a local, high-linear energy transfer (LET) dose aimed at destroying the inflamed synovial membrane. For successful treatment via BNCS, a boron-labeled compound exhibiting both high synovial uptake and long retention time is necessary. Currently, the in vivo uptake behavior of potentially useful boronated compounds is evaluated in the knee joints of rabbits in which arthritis has been induced. This strategy involves the sacrifice and dissection of a large number of animals. An in vivo 10B screening approach is therefore under investigation with the goal of significantly reducing the number of animals needed for compound evaluation via dissection studies. The 'in vivo prompt gamma neutron activation analysis' (IVPGNAA) approach uses a narrow neutron beam to irradiate the knee from several angular positions following the intra-articular injection of a boronated compound whose uptake characteristics are unknown. A high-purity germanium detector collects the 478 keV gamma photons produced by the 10B capture reactions. The 10B distribution in the knee is then reconstructed by solving a system of simultaneous equations using a weighted least squares algorithm. To study the practical feasibility of IVPGNAA, simulation data were generated with the Monte Carlo N-particle transport code. The boron-containing region of a rabbit knee was partitioned into 8 compartments, and the 10B prompt gamma signals were tallied from 16 angular positions. Results demonstrate that for this

  12. Knee Bursitis

    MedlinePlus

    ... make a diagnosis of knee bursitis during a physical exam. Your doctor will inspect your knee by: Comparing the condition of both knees, particularly if only one is painful Gently pressing on different areas of your knee to detect warmth, swelling and the source of pain Carefully moving ...

  13. Historical Special Topic Overview on Rabbit Comparative Biology Biology of the Rabbit

    PubMed Central

    Brewer, Nathan R.

    2006-01-01

    Editor’s note: In recognition of Dr. Nathan Brewer’s many years of dedicated service to AALAS and the community of research animal care specialists, the premier issue of JAALAS includes the following compilation of Dr. Brewer’s essays on rabbit anatomy and physiology. These essays were originally published in the ASLAP newsletter (formerly called Synapse), and are reprinted here with the permission and endorsement of that organization. I would like to thank Nina Hahn, Jane Lacher, and Nancy Austin for assistance in compiling these essays. Publishing this information in JAALAS allows Dr. Brewer’s work to become part of the searchable literature for laboratory animal science and medicine and also assures that the literature references and information he compiled will not be lost to posterity. However, readers should note that this material has undergone only minor editing for style, has not been edited for content, and, most importantly, has not undergone peer review. With the agreement of the associate editors and the AALAS leadership, I elected to forego peer review of this work, in contradiction to standard JAALAS policy, based on the status of this material as pre-published information from an affiliate organization that holds the copyright and on the esteem in which we hold for Dr. Brewer as a founding father of our organization. –Linda A. Toth, Editor in Chief, AALAS Journals PMID:16539330

  14. A randomised controlled trial comparing skin closure in total knee arthroplasty in the same knee: nylon sutures versus skin staples

    PubMed Central

    Iamthanaporn, K.; Hongnaparak, T.; Tangtrakulwanich, B.

    2016-01-01

    Objectives Nylon sutures and skin staples are used commonly in total knee arthroplasty (TKA) surgical wound closure. However, there is no study that compares the wound healing efficacy and patient satisfaction scores of both techniques in the same knee. Methods We randomised 70 patients who underwent primary TKA into two groups. In one group of 34 patients, the skin at the upper half of the wound was closed with skin staples and the lower half of the wound was closed with simple interrupted nylon sutures. In the other group of 36 patients, the skin at the upper half of the wound was closed with nylon stitches and the lower half of the wound was closed with skin staples. We recorded the wound closure time, pain score at the time of stitch removal, wound complication rate, patient satisfaction score, and the Hollander wound evaluation score at the post-operative periods of five days, 14 days, six weeks, three months, and six months. Each half wound was analysed separately. Results The mean patient body mass index was 26.8 kg/m2 (standard deviation 6.3). A total of 70 nylon stitched wounds and 70 skin stapled wounds were analysed. There were no significant differences in wound complication rates, patient satisfaction score, and the Hollander wound evaluation score between both types of wounds (p > 0.05). The wound closure time for skin stapled wounds was significantly lower than the nylon stitched wounds (p < 0.001). However, the skin stapled wounds had a significantly higher pain score at the time of stitch removal (p < 0.001). Conclusion Skin staples and nylon stitches had comparable results with respect to wound healing and patient satisfaction in TKA wound closure in non-obese patients. The benefit of skin staples over nylon stitches was a decrease in operative time, but was more painful upon removal. Cite this article: V. Yuenyongviwat. A randomised controlled trial comparing skin closure in total knee arthroplasty in the same knee: nylon sutures versus skin

  15. The effect of a biphasic injectable bone substitute on the interface strength in a rabbit knee prosthesis model

    PubMed Central

    2013-01-01

    Background In joint prosthetic surgery, various methods are used to provide implant stability. We used an injectable bone substitute, composed of calcium sulfate/hydroxyapatite, as bone defect filler to stabilize a tibia prosthesis in an experimental rabbit model. The aim of the study was to investigate and compare the stability of prosthetic fixation with and without the use of an injectable bone substitute. Methods Sixteen rabbits were used and the tibia prostheses were implanted bilaterally, one side with the prosthesis alone and the other side with the prosthesis and calcium sulfate/hydroxyapatite (Cerament™). The rabbits were randomly divided into two groups and euthanized after 6 and 12 weeks, respectively. The prosthesis was extracted measuring the pull-out force in an Instron tester, and the bone surrounding the former prosthesis site was analyzed by histology, histomorphometry, and micro-computed tomography. Results At 6 weeks no difference in maximum pull-out force was found between the prostheses fixed with or without Cerament™. At 12 weeks the maximum pull-out force for the prostheses with Cerament™ was significantly higher than that for the prostheses without Cerament™ (p = 0.04). The maximum pull-out force at 12 weeks was significantly higher than that at 6 weeks for the prostheses fixed with Cerament™ (p = 0.03) but not for the prostheses without. Conclusion We conclude that early prosthesis-bone interface strength is not influenced by a bone substitute. However, during remodeling, the bone substitute might provide improved mechanical support for the prosthesis. The results support further studies of the use of injectable calcium sulfate/hydroxyapatite in fixation of prosthetic joint implants. PMID:23899023

  16. Aspartic Acid Racemization Reveals a High Turnover State in Knee Compared with Hip Osteoarthritic Cartilage

    PubMed Central

    Catterall, Jonathan B; Zura, Robert D; Bolognesi, Michael P; Kraus, Virginia Byers

    2016-01-01

    Objective We investigated tissue turnover in healthy and osteoarthritic cartilage. We challenge long held views that osteoarthritis (OA) is dominated by a similar turnover process in all joints and present evidence that hip and knee cartilage respond very differently to OA. Methods D- and L-Aspartate (Asp) were quantified for whole cartilage, collagen and non-collagenous components of cartilage obtained at the time of joint replacement. We computed the Asp racemization ratio (Asp-RR=D/D+L Asp), reflecting the proportion of old to total protein, for each component. Results Compared with hip OA, knee OA collagen fibrils (P<0.0001), collagen (p=0.007), and non-collagenous proteins (p=0.0003) had significantly lower age-adjusted mean Asp-RRs consistent with elevated protein synthesis in knee OA. Knee OA collagen had a mean hydroxyproline/proline (H/P) ratio of 1.2 consistent with the presence of type III collagen whereas hip OA collagen had a mean H/P ratio of 0.99 consistent with type II collagen. Based on Asp-RR, the relative age was significantly different in knee and hip OA (p<0.0005); on average OA knees were estimated to be 30yrs ‘younger’, and OA hips 10yrs ‘older’ than non-OA. Conclusions The metabolic response to OA was strikingly different by joint site. Knee OA cartilage evinced an anabolic response that appeared to be absent in hip OA cartilage. These results challenge the long held view that OA cartilage is capable of only minimal repair and that collagen loss is irreversible. PMID:26417696

  17. How does surgery compare with advanced intra-articular therapies in knee osteoarthritis: current thoughts

    PubMed Central

    Wehling, Peter; Moser, Carsten; Maixner, William

    2016-01-01

    The objectives of osteoarthritis (OA) management are to reduce pain and inflammation, slow cartilage degradation, improve function and reduce disability. Current strategies for managing knee OA include nonpharmacological interventions, oral pharmacological treatments, localized intra-articular injections, and surgery. It has become evident that the inflammatory response is a key contributor to the development and progression of knee OA. Signaling pathways involving growth factors and cytokines are being investigated for the development of new therapies that target the underlying biological processes causing the disease. This concept of ‘molecular orthopedics’ enables more patient-centered diagnostic and treatment strategies. In contrast to other conservative therapies, which ultimately only address OA symptoms, intra-articular injections, in particular autologous conditioned serum (ACS), provide benefits that have the potential to outweigh those of established pharmacological treatments and surgery. Surgery has historically been considered the final solution for treatment of knee OA, both by treating physicians and by patients; however, there are increasing concerns regarding the lack of randomized clinical trials providing evidence to support this opinion. Intra-articular injection of ACS has demonstrated efficacy as a treatment for knee OA in a number of studies, with a very low rate of adverse events and side effects, compared with surgery. Treatment with ACS utilizes the release of anti-inflammatory cytokines and regenerative growth factors to support the natural healing processes in the knee, and has the potential to provide a valuable alternative to surgical intervention. PMID:27247634

  18. Early in situ changes in chondrocyte biomechanical responses due to a partial meniscectomy in the lateral compartment of the mature rabbit knee joint.

    PubMed

    Fick, J M; P Ronkainen, A; Madden, R; Sawatsky, A; Tiitu, V; Herzog, W; Korhonen, R K

    2016-12-08

    We determined the biomechanical responses of chondrocytes to indentation at specific locations within the superficial zone of cartilage (i.e. patellar, femoral groove, femoral condylar and tibial plateau sites) taken from female New Zealand white rabbits three days after a partial meniscectomy in the lateral compartment of a knee joint. Confocal laser scanning microscopy combined with a custom indentation system was utilized to image chondrocyte responses at sites taken from ten contralateral and experimental knee joints. Cell volume, height, width and depth changes, global, local axial and transverse strains and Young׳s moduli were determined. Histological assessment was performed and proteoglycan content from the superficial zone of each site was determined. Relative to contralateral group cells, patellar, femoral groove and lateral femoral condyle cells in the experimental group underwent greater volume decreases (p < 0.05), due to smaller lateral expansions (with greater decreases in cell height only for the lateral femoral condyle cells; p < 0.05) whereas medial femoral and medial tibial plateau cells underwent smaller volume decreases (p < 0.05), due to less deformation in cell height (p < 0.05). Proteoglycan content was reduced in the patellar (p > 0.05), femoral groove, medial femoral condyle and medial tibial plateau experimental sites (p < 0.05). The findings suggest: (i) cell biomechanical responses to cartilage loading in the rabbit knee joint can become altered as early as 3 days after a partial meniscectomy, (ii) are site-specific, and (iii) occur before alterations in tissue mechanics or changes detectable with histology.

  19. Comparative study of fermentation and methanogen community structure in the digestive tract of goats and rabbits.

    PubMed

    Abecia, L; Fondevila, M; Rodríguez-Romero, N; Martínez, G; Yáñez-Ruiz, D R

    2013-05-01

    Methane is the most important anthropogenic contribution to climate change after carbon dioxide and represents a loss of feed energy for the animal, mainly for herbivorous species. However, our knowledge about the ecology of Archaea, the microbial group responsible for methane synthesis in the gut, is very poor. Moreover, it is well known that hindgut fermentation differs from rumen fermentation. The composition of archaeal communities in fermentation compartments of goats and rabbits were investigated using DGGE to generate fingerprints of archaeal 16S rRNA gene. Ruminal contents and faeces from five Murciano-Granadina goats and caecal contents of five commercial White New Zealand rabbits were compared. Diversity profile of methanogenic archaea was carried out by PCR-DGGE. Quantification of methanogenic archaea and the abundance relative to bacteria was determined by real-time PCR. Methanogenic archaeal species were relatively constant across species. Dendrogram from DGGE of the methanogen community showed one cluster for goat samples with two sub-clusters by type of sample (ruminal and faeces). In a second cluster, samples from rabbit were grouped. No differences were found either in richness or Shannon index as diversity indexes. Although the primer sets used was developed to investigate rumen methanogenic archaeal community, primers specificity did not affect the assessment of rabbit methanogen community structure. Rumen content showed the highest number or methanogenic archaea (log₁₀ 9.36), followed by faeces (log₁₀ 8.52) and showing rabbit caecum the lower values (log₁₀ 5.52). DGGE profile showed that pre-gastric and hindgut fermenters hold a very different methanogen community. Rabbits hold a microbial community of similar complexity than that in ruminants but less abundant, which agrees with the type of fermentation profile.

  20. Comparative hypoglycemic activity of different fractions of Thymus serpyllum L. in alloxan induced diabetic rabbits.

    PubMed

    Alamgeer, -; Mushtaq, Muhammad Naveed; Bashir, Sajid; Ullah, Ikram; Karim, Sabeha; Rashid, Muhammad; Malik, Muhammad Nasir Hayat; Rashid, Haroonur

    2016-09-01

    The aim of present study was to evaluate and compare the hypoglycemic activity of different solvents extracts of Thymus serpyllum in rabbits. Diabetes was induced with single intravenous injection of alloxan monohydrate (150mg/kg). Glibenclamide and acarbose were used as standard drugs. The crude powder of Thymus serpyllum (500 mg/kg b.w) significantly reduced blood glucose level in both normal and diabetic rabbits. Various extracts of Thymus serpyllum were compared for their hypoglycemic activity in diabetic rabbits. Ether and aqueous extracts significantly reduced the blood glucose level with maximum effect (p<0.001) produced by aqueous extract, which was selected for further study. Aqueous extract significantly inhibited the rise in glucose level in oral glucose tolerance test. The extract showed synergistic effect with different doses of insulin; however serum insulin level of the diabetic rabbits was not significantly increased by the extract. HbA1c level was significantly (p<0.05) reduced whereas hemoglobin level was significantly increased in three months study. Phytochemical screening of the aqueous extract showed the presence of alkaloids, flavonoids, tannins, terpinoids, reducing sugar and cardiac glycosides. It is concluded that the aqueous extract might be used alone or in combination with insulin to manage diabetes and its associated complications.

  1. Functional ability perceived by individuals following total knee arthroplasty compared to age-matched individuals without knee disability.

    PubMed

    Finch, E; Walsh, M; Thomas, S G; Woodhouse, L J

    1998-04-01

    A comparison of function of individuals 1 year after total knee arthroplasty (TKA) with healthy control subjects (controls) meaningfully describes outcome in these patients. Perception of function measured by two questionnaires, the Lower Extremity Activity Profile (LEAP) and the Western Ontario McMaster Osteoarthritis Index (WOMAC), and walking and stair performance was compared between 29 patients, 1 year after TKA, and 40 controls. There was significantly greater perceived difficulty with function in patients with TKA than in controls. In TKA men, LEAP and WOMAC scores correlated respectively with self-paced walk speed (r = -.71 and -.55) and stair performance time (r = 0.70 and 0.68). In TKA women, LEAP difficulty score correlated with self-paced walk speed (r = -.41) and stair performance time (r = -0.71). By 1 year, TKA subjects regained 80% of the function of controls. Perception of function after TKA can be measured by either questionnaire in men; however, the LEAP is the preferable questionnaire with women.

  2. Comparative Effectiveness of Tai Chi Versus Physical Therapy for Knee Osteoarthritis

    PubMed Central

    Wang, Chenchen; Schmid, Christopher H.; Iversen, Maura D.; Harvey, William F.; Fielding, Roger A.; Driban, Jeffrey B.; Price, Lori Lyn; Wong, John B.; Reid, Kieran F.; Rones, Ramel; McAlindon, Timothy

    2016-01-01

    Background Few remedies effectively treat long-term pain and disability from knee osteoarthritis. Studies suggest that Tai Chi alleviates symptoms, but no trials have directly compared Tai Chi with standard therapies for osteoarthritis. Objective To compare Tai Chi with standard physical therapy for patients with knee osteoarthritis. Design Randomized, 52-week, single-blind comparative effectiveness trial. (ClinicalTrials.gov: NCT01258985) Setting An urban tertiary care academic hospital. Patients 204 participants with symptomatic knee osteoarthritis (mean age, 60 years; 70% women; 53% white). Intervention Tai Chi (2 times per week for 12 weeks) or standard physical therapy (2 times per week for 6 weeks, followed by 6 weeks of monitored home exercise). Measurements The primary outcome was Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score at 12 weeks. Secondary outcomes included physical function, depression, medication use, and quality of life. Results At 12 weeks, the WOMAC score was substantially reduced in both groups (Tai Chi, 167 points [95% CI, 145 to 190 points]; physical therapy, 143 points [CI, 119 to 167 points]). The between-group difference was not significant (24 points [CI, −10 to 58 points]). Both groups also showed similar clinically significant improvement in most secondary outcomes, and the benefits were maintained up to 52 weeks. Of note, the Tai Chi group had significantly greater improvements in depression and the physical component of quality of life. The benefit of Tai Chi was consistent across instructors. No serious adverse events occurred. Limitation Patients were aware of their treatment group assignment, and the generalizability of the findings to other settings remains undetermined. Conclusion Tai Chi produced beneficial effects similar to those of a standard course of physical therapy in the treatment of knee osteoarthritis. Primary Funding Source National Center for Complementary and Integrative Health of

  3. COMPARATIVE MACROSCOPIC STUDY OF OSTEOCHONDRAL DEFECTS PRODUCED IN FEMURS OF RABBITS REPAIRED WITH BIOPOLYMER GEL CANE SUGAR

    PubMed Central

    de Albuquerque, Paulo Cezar Vidal Carneiro; dos Santos, Saulo Monteiro; de Andrade Aguiar, José Lamartine; Filho, Nicodemus Pontes; de Mello, Roberto José Vieira; Costa, Mariana Lúcia Correia Ramos; de Albuquerque Olbertz, Clarissa Miranda Carneiro; de Souza Almeida, Tarciana Mendonça; da Silva Santos, Alessandro Henrique; da Silva, Joacil Carlos

    2015-01-01

    Objective: To study the surface, coloring, consistency, continuity and healing of osteochondral defects produced in the femoral condyles of rabbits and filled with sugar cane biopolymer gel (SCBG), after 90, 120 and 180 days, and in comparison with a control group. Method: Sixteen adult New Zealand white rabbits aged 6 to 7 months, weighing between 2 and 2.5 kg and without locomotor system abnormalities were studied. In all the animals, a defect was made in the femoral condyles of the right and left knees, measuring 3.2 mm in diameter and 4 mm in depth, using a trephine. The animals were divided into two groups: study group formed by the right knees, in which the medial and lateral condyles received implants of SCBG; and control group formed by the left knees, in which the medial and lateral condyles were allowed to heal naturally. The knees were assessed 90, 120 and 180 days after the operation. After the animals had been sacrificed, the anatomical specimens were resected and placed in Bouin's solution. They were then photographed with a Nikon Coolpix 5400® coupled to a Nikon SM2800® stereoscopic loupe, to analyze the surface, coloring, consistency, continuity and healing. Results: The results were evaluated using the chi-square test. There were no significant differences in the macroscopic assessments of healing between the study and control groups. Conclusion: With regard to the surface, coloring, consistency, continuity and healing of the defects, the macroscopic appearance of the tissue repaired with SCBG was similar to that of the control group. PMID:27027057

  4. Comparative evaluation of the aphrodisiac efficacy of sildenafil and Carpolobia lutea root extract in male rabbits

    PubMed Central

    Dare, Ayobami; Salami, Shakiru Ademola; Kunle-Alabi, Olufadekemi Tolulope; Akindele, Opeyemi Oreofe; Raji, Yinusa

    2015-01-01

    Aims: In spite of the folkloric use of the root of Carpolobia lutea as a sexual stimulant in man, there has been limited scientific proof of its efficacy. This study compares the efficacy of methanol extract of C. lutea root (MECLR) and sildenafil on the sexual activity of male rabbits. Methods: 20 adult male rabbits were grouped into four of five rabbits each. Groups 1-4 were treated orally for 28 days with 2 ml/kg 1% Tween-20 (vehicle), 40 mg/kg MECLR, 80 mg/kg MECLR, and 0.5 mg/kg sildenafil citrate (SC), respectively. Sexual activities of males from each group were assessed by cohabiting them with sexually receptive female at estrus on days 0, 1, 3, and 5 using digital camera mounted on mating arena. Serum testosterone and nitric oxide concentration of the corpora cavernosa homogenates were also determined. Results: MECLR caused a dose-dependent significant increase in mount frequency, intromission frequency and ejaculatory latency (EL) while it reduced mount latency, intromission latency and post EL (similar to SC) when compared with the control. MECLR also caused significant increase in nitric oxide concentration in corpora cavernosa but no change in serum testosterone concentration. Conclusions: Results suggest that MECLR enhances male sexual activity possibly by augmenting nitric oxide concentration. This study thus provides a novel scientific rationale for the use of C. lutea in the management of penile erectile dysfunction and impaired libido. PMID:26649235

  5. Knee Joint Distraction Compared to Total Knee Arthroplasty for Treatment of End Stage Osteoarthritis: Simulating Long-Term Outcomes and Cost-Effectiveness

    PubMed Central

    van der Woude, J. A. D.; Nair, S. C.; Custers, R. J. H.; van Laar, J. M.; Kuchuck, N. O.; Lafeber, F. P. J. G.; Welsing, P. M. J.

    2016-01-01

    Objective In end-stage knee osteoarthritis the treatment of choice is total knee arthroplasty (TKA). An alternative treatment is knee joint distraction (KJD), suggested to postpone TKA. Several studies reported significant and prolonged clinical improvement of KJD. To make an appropriate decision regarding the position of this treatment, a cost-effectiveness and cost-utility analysis from healthcare perspective for different age and gender categories was performed. Methods A treatment strategy starting with TKA and a strategy starting with KJD for patients of different age and gender was simulated. To extrapolate outcomes to long-term health and economic outcomes a Markov (Health state) model was used. The number of surgeries, QALYs, and treatment costs per strategy were calculated. Costs-effectiveness is expressed using the cost-effectiveness plane and cost-effectiveness acceptability curves. Results Starting with KJD the number of knee replacing procedures could be reduced, most clearly in the younger age categories; especially revision surgery. This resulted in the KJD strategy being dominant (more effective with cost-savings) in about 80% of simulations (with only inferiority in about 1%) in these age categories when compared to TKA. At a willingness to pay of 20.000 Euro per QALY gained, the probability of starting with KJD to be cost-effective compared to starting with a TKA was already found to be over 75% for all age categories and over 90–95% for the younger age categories. Conclusion A treatment strategy starting with knee joint distraction for knee osteoarthritis has a large potential for being a cost-effective intervention, especially for the relatively young patient. PMID:27171268

  6. Exercise in children with joint hypermobility syndrome and knee pain: a randomised controlled trial comparing exercise into hypermobile versus neutral knee extension

    PubMed Central

    2013-01-01

    Background Knee pain in children with Joint Hypermobility Syndrome (JHS) is traditionally managed with exercise, however the supporting evidence for this is scarce. No trial has previously examined whether exercising to neutral or into the hypermobile range affects outcomes. This study aimed to (i) determine if a physiotherapist-prescribed exercise programme focused on knee joint strength and control is effective in reducing knee pain in children with JHS compared to no treatment, and (ii) whether the range in which these exercises are performed affects outcomes. Methods A prospective, parallel-group, randomised controlled trial conducted in a tertiary hospital in Sydney, Australia compared an 8 week exercise programme performed into either the full hypermobile range or only to neutral knee extension, following a minimum 2 week baseline period without treatment. Randomisation was computer-generated, with allocation concealed by sequentially numbered opaque sealed envelopes. Knee pain was the primary outcome. Quality of life, thigh muscle strength, and function were also measured at (i) initial assessment, (ii) following the baseline period and (iii) post treatment. Assessors were blinded to the participants’ treatment allocation and participants blinded to the difference in the treatments. Results Children with JHS and knee pain (n=26) aged 7-16 years were randomly assigned to the hypermobile (n=12) or neutral (n=14) treatment group. Significant improvements in child-reported maximal knee pain were found following treatment, regardless of group allocation with a mean 14.5 mm reduction on the visual analogue scale (95% CI 5.2 – 23.8 mm, p=0.003). Significant differences between treatment groups were noted for parent-reported overall psychosocial health (p=0.009), specifically self-esteem (p=0.034), mental health (p=0.001) and behaviour (p=0.019), in favour of exercising into the hypermobile range (n=11) compared to neutral only (n=14). Conversely, parent

  7. Knee pain, knee injury, knee osteoarthritis & work.

    PubMed

    Dulay, Gurdeep S; Cooper, C; Dennison, E M

    2015-06-01

    Symptomatic knee osteoarthritis (OA) can be viewed as the end result of a molecular cascade which ensues after certain triggers occur and ultimately results in irreversible damage to the articular cartilage. The clinical phenotype that knee OA can produce is variable and often difficult to accurately predict. This is further complicated by the often poor relationship between radiographic OA and knee pain. As a consequence, it can be difficult to compare studies that use different definitions of OA. However, the literature suggests that while there are multiple causes of knee OA, two have attracted particular attention over recent years; occupation related knee OA and OA subsequent to previous knee injury. The evidence of a relationship, and the strength of this association, is discussed in this chapter.

  8. Serum cytokines are increased and circulating micronutrients are not altered in subjects with early compared to advanced knee osteoarthritis.

    PubMed

    Barker, Tyler; Rogers, Victoria E; Henriksen, Vanessa T; Aguirre, Dale; Trawick, Roy H; Rasmussen, G Lynn; Momberger, Nathan G

    2014-08-01

    Knee osteoarthritis (OA) is a leading cause of physical disability. At the early stage of knee OA, the increase in synovial fluid cytokine concentrations could contribute to the pathogenesis of OA by degrading articular cartilage. It is unknown, however, if inflammatory cytokines increase systemically at the early or advanced stage of knee OA. The systemic increase of inflammatory cytokines could be detrimental to the endogenous status of micronutrients that protect against excessive inflammation and cytokine-mediated events. The purpose of this study was to test the hypothesis that an increase in serum cytokines associate with a decrease in circulating micronutrients in subjects with early compared to advanced knee OA. Advanced knee OA subjects (n=14) displayed radiographic, pain, and muscular weakness symptoms of knee OA. Early knee OA subjects (n=14) were matched (age, gender, and body mass index) to the advanced OA group and displayed one or two of the aforementioned symptoms of knee OA. Inflammatory cytokines, vitamins C (ascorbic acid), D (25-hydroxyvitamin D), and E (α- and γ-tocopherols), and β-carotene were measured in fasting blood samples. In the early OA group, serum tumor necrosis factor (TNF)-α, interleukin (IL)-5, IL-6, IL-12, and IL-13 concentrations were significantly (all p<0.05) increased. Circulating ascorbic acid, 25-hydroxyvitamin D, α- and γ-tocopherol's, and β-carotene concentrations were not significantly different between groups. Based on these preliminary results, we conclude that the systemic increase of inflammatory cytokines is not associated with a decrease in circulating micronutrients in subjects with early compared to advanced knee OA.

  9. Release of Cu2+ from a copper-filled TiO2 coating in a rabbit model for total knee arthroplasty.

    PubMed

    Mauerer, Andreas; Lange, Bastian; Welsch, Goetz Hannes; Heidenau, Frank; Adler, Werner; Forst, Raimund; Richter, Richard Heiner

    2014-03-01

    The aim of this study was the investigation of a copper-filled TiO2 coating, that in vitro showed good antibacterial properties combined with good tissue tolerance in an animal model. To better understand the antibacterial mechanism of the bioactive coating the release of copper (Cu) ions over time was monitored to be able to detect possible threats as well as possible fields of application. 30 New Zealand White rabbits were divided into two groups with 15 animals per group. In group 1 (control group) Ti6Al4 V bolts were implanted into the distal femur, in group 2 the Ti6Al4 V bolts were coated with four TiO2-coatings with integrated Cu(2+)-ions (4 × Cu-TiO2). Blood tests were performed weekly until the animals were sacrificed 4 weeks postoperative. The maximum peak of Cu and ceruloplasmin concentration could be seen in both groups one week postoperative, whereas the Cu values in group II were significantly higher. The Cu concentration in both groups approximated the initial basic values 4 weeks postoperative. The 4 × Cu-TiO2 coating tested in our rabbit model for total knee arthroplasty is an active coating that releases potentially antibacterial Cu(2+) for 4 weeks with a peak 1 week postoperative. The bioactive coating could be a promising approach for a use in the field of implant related infection, orthopaedic revision and tumor surgery in the future.

  10. Comparing analgesic effects of a topical herbal mixed medicine with salicylate in patients with knee osteoarthritis.

    PubMed

    Zahmatkash, Mohsen; Vafaeenasab, Mohammad Reza

    2011-07-01

    Knee osteoarthritis is the most common cause of disability among people and it is a common disease of joints that can lead to cartilage damage. In this study the analgesic effects of a herbal ointment containing cinnamon, ginger, mastic (Saghez) and sesame oil is compared with Salicylate ointment in patients suffering from knee osteoarthritis. It was a double-blind randomized controlled trail study. Patients with diagnosed arthritis were involved in the study and they were divided in two groups via block randomization method. For six weeks, twice a day, intervention group applied herbal ointment and control group used Salicylate ointment. The severity of pain, morning stiffness and limited motion were measured using Visual Analog Pain Scale. In order to analyze the trends of these three indexes, repeated measurement test was used. Ninety two participates with the mean age of 52.2 (+/- 12.4) years and with the mean disease period of 30.45 (+/- 30.3) months were involved in the study. There was no significant difference between two groups regarding the distribution of sex, weight, height, BMI and the duration of illness. No statistical difference was observed between two groups regarding pain relief, morning stiffness and limited motion; nevertheless in repeated measurements during second, forth and sixth weeks in both groups the decreasing trend of these three indexes had been statistically significant (p < 0.0001). It seems that using this herbal combination is clinically effective for patients suffering from knee osteoarthritis in order to decrease their pain, morning stiffness and limited motion; its effect is comparable with Salicylate ointment.

  11. Comparing rat and rabbit embryo-fetal developmental toxicity data for 379 pharmaceuticals: on systemic dose and developmental effects.

    PubMed

    Theunissen, Peter T; Beken, Sonia; Beyer, Bruce; Breslin, William J; Cappon, Gregg D; Chen, Connie L; Chmielewski, Gary; de Schaepdrijver, Luc; Enright, Brian; Foreman, Jennifer E; Harrouk, Wafa; Hew, Kok-Wah; Hoberman, Alan M; Y Hui, Julia; Knudsen, Thomas B; Laffan, Susan B; Makris, Susan L; Martin, Matthew; McNerney, Mary Ellen; Siezen, Christine L; Stanislaus, Dinesh J; Stewart, Jane; Thompson, Kary E; Tornesi, Belen; Van der Laan, Jan Willem; Weinbauer, Gerhard F; Wood, Sandra; Piersma, Aldert H

    2016-10-21

    A database of embryo-fetal developmental toxicity (EFDT) studies of 379 pharmaceutical compounds in rat and rabbit was analyzed for species differences based on toxicokinetic parameters of area under the curve (AUC) and maximum concentration (Cmax) at the developmental lowest adverse effect level (dLOAEL). For the vast majority of cases (83% based on AUC of n = 283), dLOAELs in rats and rabbits were within the same order of magnitude (less than 10-fold different) when compared based on available data on AUC and Cmax exposures. For 13.5% of the compounds the rabbit was more sensitive and for 3.5% of compounds the rat was more sensitive when compared based on AUC exposures. For 12% of the compounds the rabbit was more sensitive and for 1.3% of compounds the rat was more sensitive based on Cmax exposures. When evaluated based on human equivalent dose (HED) conversion using standard factors, the rat and rabbit were equally sensitive. The relative extent of embryo-fetal toxicity in the presence of maternal toxicity was not different between species. Overall effect severity incidences were distributed similarly in rat and rabbit studies. Individual rat and rabbit strains did not show a different general distribution of systemic exposure LOAELs as compared to all strains combined for each species. There were no apparent species differences in the occurrence of embryo-fetal variations. Based on power of detection and given differences in the nature of developmental effects between rat and rabbit study outcomes for individual compounds, EFDT studies in two species have added value over single studies.

  12. Knee joint position sense of roller hockey players: a comparative study.

    PubMed

    Venâncio, João; Lopes, Diogo; Lourenço, Joaquim; Ribeiro, Fernando

    2016-06-01

    This study aimed to compare knee joint position sense of roller hockey players with an age-matched group of non-athletes. Forty-three male participants voluntarily participated in this cross-sectional study: 21 roller hockey players (mean age: 23.2 ± 4.2 years old, mean weight: 81.8 ± 9.8 kg, mean height: 180.5 ± 4.1 cm) and 22 age-matched non-athletes (mean age: 23.7 ± 3.9 years old, mean weight: 85.0 ± 6.2 kg, mean height: 181.5 ± 5.0 cm). Knee joint position sense of the dominant limb was evaluated using a technique of open-kinetic chain and active knee positioning. Joint position sense was reported using absolute, relative and variable angular errors. The main results indicated that the group of roller hockey players showed significantly lower absolute (2.4 ± 1.2º vs. 6.5 ± 3.2º, p ≤ 0.001) and relative (1.7 ± 2.1º vs. 5.8 ± 4.4º, p ≤ 0.001) angular errors in comparison with the non-athletes group. In conclusion, the results from this present study suggest that proprioceptive acuity, assessed by measuring joint position sense, is increased in roller hockey players. The enhanced proprioception of the roller hockey players could contribute to injury prevention and improved performance during sporting activities.

  13. Three-dimensional bioprinting of multilayered constructs containing human mesenchymal stromal cells for osteochondral tissue regeneration in the rabbit knee joint.

    PubMed

    Shim, Jin-Hyung; Jang, Ki-Mo; Hahn, Sei Kwang; Park, Ju Young; Jung, Hyuntae; Oh, Kyunghoon; Park, Kyeng Min; Yeom, Junseok; Park, Sun Hwa; Kim, Sung Won; Wang, Joon Ho; Kim, Kimoon; Cho, Dong-Woo

    2016-02-04

    The use of cell-rich hydrogels for three-dimensional (3D) cell culture has shown great potential for a variety of biomedical applications. However, the fabrication of appropriate constructs has been challenging. In this study, we describe a 3D printing process for the preparation of a multilayered 3D construct containing human mesenchymal stromal cells with a hydrogel comprised of atelocollagen and supramolecular hyaluronic acid (HA). This construct showed outstanding regenerative ability for the reconstruction of an osteochondral tissue in the knee joints of rabbits. We found that the use of a mechanically stable, host-guest chemistry-based hydrogel was essential and allowed two different types of extracellular matrix (ECM) hydrogels to be easily printed and stacked into one multilayered construct without requiring the use of potentially harmful chemical reagents or physical stimuli for post-crosslinking. To the best of our knowledge, this is the first study to validate the potential of a 3D printed multilayered construct consisting of two different ECM materials (atelocollagen and HA) for heterogeneous tissue regeneration using an in vivo animal model. We believe that this 3D printing-based platform technology can be effectively exploited for regeneration of various heterogeneous tissues as well as osteochondral tissue.

  14. Auxiliary proteins that facilitate formation of collagen-rich deposits in the posterior knee capsule in a rabbit-based joint contracture model.

    PubMed

    Steplewski, Andrzej; Fertala, Jolanta; Beredjiklian, Pedro K; Abboud, Joseph A; Wang, Mark L Y; Namdari, Surena; Barlow, Jonathan; Rivlin, Michael; Arnold, William V; Kostas, James; Hou, Cheryl; Fertala, Andrzej

    2016-03-01

    Post-traumatic joint contracture is a debilitating consequence of trauma or surgical procedures. It is associated with fibrosis that develops regardless of the nature of initial trauma and results from complex biological processes associated with inflammation and cell activation. These processes accelerate production of structural elements of the extracellular matrix, particularly collagen fibrils. Although the increased production of collagenous proteins has been demonstrated in tissues of contracted joints, researchers have not yet determined the complex protein machinery needed for the biosynthesis of collagen molecules and for their assembly into fibrils. Consequently, the purpose of our study was to investigate key enzymes and protein chaperones needed to produce collagen-rich deposits. Using a rabbit model of joint contracture, our biochemical and histological assays indicated changes in the expression patterns of heat shock protein 47 and the α-subunit of prolyl 4-hydroxylase, key proteins in processing nascent collagen chains. Moreover, our study shows that the abnormal organization of collagen fibrils in the posterior capsules of injured knees, rather than excessive formation of fibril-stabilizing cross-links, may be a key reason for observed changes in the mechanical characteristics of injured joints. This result sheds new light on pathomechanisms of joint contraction, and identifies potentially attractive anti-fibrotic targets.

  15. Hypotensive effects of hemopressin and bradykinin in rabbits, rats and mice. A comparative study.

    PubMed

    Blais, Paul-André; Côté, Jérôme; Morin, Josée; Larouche, Annie; Gendron, Gabrielle; Fortier, Audrey; Regoli, Domenico; Neugebauer, Witold; Gobeil, Fernand

    2005-08-01

    Hemopressin is a novel vasoactive nonapeptide derived from hemoglobin's alpha-chain as recently reported by Rioli et al. [Rioli V, Gozzo FC, Heimann AS, Linardi A, Krieger JE, Shida CS, et al. Novel natural peptide substrates for endopeptidase 24.15, neurolysin, and angiotensin-converting enzyme. J Biol Chem 2003;278(10):8547-55]. In anesthetized male Wistar rats, this peptide exhibited hypotensive actions similar to those of bradykinin (BK) when administered intravenously (i.v.), and was found to be metabolized both in vitro and in vivo by several peptidases, including the angiotensin-converting enzyme (ACE). In this study, these findings were expanded upon by examining: (i) the degradation kinetics following incubation with ACE purified from rabbit lung and (ii) the blood pressure lowering effects of HP and BK injected i.v. or intra-arterially (i.a.) in male rabbits, rats, and mice. Our findings demonstrate that, in vitro, HP and BK are both degraded by ACE, but at different velocity rates. Furthermore, both HP and BK induced transient hypotension in all animals tested, although the responses to HP relative to the administration sites were significantly lower (by 10-100-fold) on an equimolar basis compared to those of BK. In rabbits, the decrease of blood pressure induced by HP (10-100 nmol/kg) did not differ whether it was administered i.v. or i.a., suggesting an absence of pulmonary/cardiac inactivation in contrast to BK (0.1-1 nmol/kg). The in vivo effect of HP was significantly potentiated in rabbits immunostimulated with bacterial lipopolysaccharide (LPS), but was unaffected by both the B2 receptor antagonist HOE 140 (0.1 micromol/kg) and captopril (100 microg/kg), contrary to BK. Therefore, HP acts as a weak hypotensive mediator, which does not activate kinin B2 receptors, but uses a functional site and/or signaling paths appearing to be up-regulated by LPS.

  16. A comparative study of candidal invasion in rabbit tongue mucosal explants and reconstituted human oral epithelium.

    PubMed

    Jayatilake, J A M S; Samaranayake, Y H; Samaranayake, L P

    2008-06-01

    The purpose of this study is to compare the light and scanning electron microscopic (SEM) features of tissue invasion by three Candida species (C. albicans, C. tropicalis, and C. dubliniensis) in two different tissue culture models: rabbit tongue mucosal explants (RTME) and reconstituted human oral epithelium (RHOE). Tongue mucosal biopsies of healthy New Zealand rabbits were maintained in explant culture using a transwell system. RHOE was obtained from Skinethic Laboratory (Nice, France). RTME and RHOE were inoculated with C. albicans, C. tropicalis, and C. dubliniensis separately and incubated at 37 degrees C, 5% CO(2), and 100% humidity up to 48 h. Light microscopic and SEM examinations of uninfected (controls) and infected tissues were performed at 24 and 48 h. C. albicans produced characteristic hallmarks of pathological tissue invasion in both tissue models over a period of 48 h. Hyphae penetrated through epithelial cells and intercellular gaps latter resembling thigmotropism. SEM showed cavitations on the epithelial cell surfaces particularly pronounced at sites of hyphal invasion. Some hyphae on RTME showed several clusters of blastospores attached in regular arrangements resembling "appareil sporifere". C. tropicalis and C. dubliniensis produced few hyphae mainly on RTME but they did not penetrate either model. Our findings indicate that multiple host-fungal interactions such as cavitations, thigmotropism, and morphogenesis take place during candidal tissue invasion. RTME described here appears to be useful in investigations of such pathogenic processes of Candida active at the epithelial front.

  17. Bioactive glass in cavitary bone defects: a comparative experimental study in rabbits

    PubMed Central

    Camargo, André Ferrari de França; Baptista, André Mathias; Natalino, Renato; de Camargo, Olavo Pires

    2015-01-01

    OBJECTIVES: To compare bioactive glass and autograft regarding their histomorphometric characteristics. METHODS: The authors conducted a prospective case-control experimental study on animals in order to compare the histomorphometric characteristics of bioactive glass versus autograft. Eight rabbits underwent surgery in which a cavitary defect was created in both proximal femurs. One side was filled with bioactive glass granules and the other, with autograft grafted from the contralateral side. The sides were randomized. Fourteen days after surgery, the animals were euthanized. RESULTS: Histologic analysis revealed that bone neoformation was equivalent among the two groups and the osteoblasts cell-count was higher in the femurs treated with bioactive glass. The osteocytes cell-count, however, was lower. The similarity in bone formation between both groups was consistent to literature findings. CONCLUSION: Bioactive glass is similar to autograft regarding bone neoformation in this animal model of cavitary bone defects. Level of Evidence III, Case-Control Study. PMID:26327802

  18. COMPARATIVE STUDY OF SPINAL AND LOCAL ANESTHESIA WITH PROPOFOL INFUSION FOR KNEE ARTHROSCOPY

    PubMed Central

    da Silva, Robson Rocha; Matos, Marcos Almeida; Madureira, Gleise; dos Santos, Indiara Gouveia

    2015-01-01

    Spinal anesthesia for knee arthroscopy is a well-documented and safe procedure. However, some complications and higher costs have been reported. Also, many orthopaedic surgeons are reluctant to use local anesthesia for fear of having to convert to general anesthesia due to inadequate pain control. The purpose of this study is to compare local with spinal anesthesia in two groups of patients submitted to knee arthroscopy. Sixty-five patients were divided in two groups; based on the anesthesia method used, and submitted to the same surgical routine and postoperative analgesia protocol. They were evaluated for analgesia, level of postoperative pain, and level of satisfaction with the type of anesthetic. The two groups did not present any significant differences in relation to perioperative analgesia and pain on the first postoperative day, neither was there any difference in relation to emotional state. However, there was a significant difference in terms of acceptance of the procedure; 100% said they would accept the procedure again in the local anesthesia group, compared with 60.5% in the spinal anesthesia group; also, 100% in the local anesthesia group said they felt encouraged by the type of anesthesia, compared with 67.7% in the spinal anesthesia group. We can conclude that local anesthesia is similar to spinal anesthesia in almost all the aspects investigated, except in terms of acceptance and patients’ level of satisfaction with the procedure. Local anesthesia can be a good alternative to spinal anesthesia, especially in outpatient departments, or when patients have restrictions to traditional models of anesthesia. PMID:27027089

  19. Comparative Analysis of Direct Hospital Care Costs between Aseptic and Two-Stage Septic Knee Revision

    PubMed Central

    Kasch, Richard; Merk, Sebastian; Assmann, Grit; Lahm, Andreas; Napp, Matthias; Merk, Harry; Flessa, Steffen

    2017-01-01

    Background The most common intermediate and long-term complications of total knee arthroplasty (TKA) include aseptic and septic failure of prosthetic joints. These complications cause suffering, and their management is expensive. In the future the number of revision TKA will increase, which involves a greater financial burden. Little concrete data about direct costs for aseptic and two-stage septic knee revisions with an in depth-analysis of septic explantation and implantation is available. Questions/Purposes A retrospective consecutive analysis of the major partial costs involved in revision TKA for aseptic and septic failure was undertaken to compare 1) demographic and clinical characteristics, and 2) variable direct costs (from a hospital department’s perspective) between patients who underwent single-stage aseptic and two-stage septic revision of TKA in a hospital providing maximum care. We separately analyze the explantation and implantation procedures in septic revision cases and identify the major cost drivers of knee revision operations. Methods A total of 106 consecutive patients (71 aseptic and 35 septic) was included. All direct costs of diagnosis, surgery, and treatment from the hospital department’s perspective were calculated as real purchase prices. Personnel involvement was calculated in units of minutes. Results Aseptic versus septic revisions differed significantly in terms of length of hospital stay (15.2 vs. 39.9 days), number of reported secondary diagnoses (6.3 vs. 9.8) and incision-suture time (108.3 min vs. 193.2 min). The management of septic revision TKA was significantly more expensive than that of aseptic failure ($12,223.79 vs. $6,749.43) (p <.001). On the level of the separate hospitalizations the mean direct costs of explantation stage ($4,540.46) were lower than aseptic revision TKA ($6,749.43) which were again lower than those of the septic implantation stage ($7,683.33). All mean costs of stays were not comparable as they

  20. Comparative Effectiveness of B and E Vitamins with Diclofenac in Reducing Pain Due to Osteoarthritis of the Knee

    PubMed Central

    Dehghan, Morteza

    2015-01-01

    Background: Knee osteoarthritis is one of the most prevalent chronic disorders. Several pharmacological and non pharmacological approaches are used to treat this disease. Today, the effect of B and E vitamins on rheumatology diseases is being discussed. In this study, the efficacy of B and E vitamins accompanied with diclofenac on pain relief in patients with knee osteoarthritis was investigated and compared. Methods: In this double-blinded clinical trial, 120 patients with knee osteoarthritis referring training Rheumatology and Orthopedics Clinic of Shahrekord University of Medical sciences were investigated. Of these patients, 12 were excluded throughout the study. The patients underwent treatment in three groups (oral diclofenac + oral B vitamin, oral diclofenac + oral vitamin E, and oral diclofenac + placebo). Pain relief was assessed by visual analogue scale (VAS) questionnaire and morning stiffness and physical function were assessed by WOMAC standard questionnaire at three times; the first examination, two weeks, and three weeks after referring. Results: The mean score of WOMAC questionnaire at VASs of knee pain, total pain severity, knee joint stiffness, and function of the last 48 hours decreased significantly in all three groups (diclofenac, E and B vitamins) from the first to third examination (P<0.001). Decrease in VAS of knee pain and function of the last 48 hours was higher in B vitamin group than the diclofenac and E vitamin group (P=0.008) and decrease in total pain severity was reported higher in B vitamin group than E vitamin and diclofenac group (P=0.019). Decrease in knee joint stiffness underwent a similar trend in the three groups. Conclusion: In view similar analgesic and anti-inflammatory properties, as well as very few, non prevalent complications of B and E vitamins, use of two or more drugs with a different mechanism of effect seems necessary to enhance their effect on osteoarthritis treatment. PMID:26005259

  1. Toxicokinetics of perfluorooctane sulfonate in rabbits under environmentally realistic exposure conditions and comparative assessment between mammals and birds.

    PubMed

    Tarazona, J V; Rodríguez, C; Alonso, E; Sáez, M; González, F; San Andrés, M D; Jiménez, B; San Andrés, M I

    2016-01-22

    This article describes the toxicokinetics of perfluorooctane sulfonate (PFOS) in rabbits under low repeated dosing, equivalent to 0.085μg/kg per day, and the observed differences between rabbits and chickens. The best fitting for both species was provided by a simple pseudo monocompartmental first-order kinetics model, regulated by two rates, and accounting for real elimination as well as binding of PFOS to non-exchangeable structures. Elimination was more rapid in rabbits, with a pseudo first-order dissipation half-life of 88 days compared to the 230 days observed for chickens. By contrast, the calculated assimilation efficiency for rabbits was almost 1, very close to full absorption, significantly higher than the 0.66 with confidence intervals of 0.64 and 0.68 observed for chickens. The results confirm a very different kinetics than that observed in single-dose experiments confirming clear dose-related differences in apparent elimination rates in rabbits, as previously described for humans and other mammals; suggesting the role of a capacity-limited saturable process resulting in different kinetic behaviours for PFOS in high dose versus environmentally relevant low dose exposure conditions. The model calculations confirmed that the measured maximum concentrations were still far from the steady state situation, and that the different kinetics between birds and mammals should may play a significant role in the biomagnifications assessment and potential exposure for humans and predators. For the same dose regime, the steady state concentration was estimated at about 36μg PFOS/L serum for rabbits, slightly above one-half of the 65μg PFOS/L serum estimated for chickens. The toxicokinetic parameters presented here can be used for higher-tier bioaccumulation estimations of PFOS in rabbits and chickens as starting point for human health exposure assessments and as surrogate values for modeling PFOS kinetics in wild mammals and bird in exposure assessment of predatory

  2. Isolation and Characterization of Synovial Mesenchymal Stem Cell Derived from Hip Joints: A Comparative Analysis with a Matched Control Knee Group

    PubMed Central

    Hatakeyama, Akihisa; Utsunomiya, Hajime; Tsukamoto, Manabu; Nakashima, Hirotaka; Nakamura, Eiichiro; Pascual-Garrido, Cecilia; Sekiya, Ichiro; Sakai, Akinori

    2017-01-01

    Purpose. To determine the characteristics of MSCs from hip and compare them to MSCs from knee. Methods. Synovial tissues were obtained from both the knee and the hip joints in 8 patients who underwent both hip and knee arthroscopies on the same day. MSCs were isolated from the knee and hip synovial samples. The capacities of MSCs were compared between both groups. Results. The number of cells per unit weight at passage 0 of synovium from the knee was significantly higher than that from the hip (P < 0.05). While it was possible to observe the growth of colonies in all the knee synovial fluid samples, it was impossible to culture cells from any of the hip samples. In adipogenesis experiments, the frequency of Oil Red-O-positive colonies and the gene expression of adipsin were significantly higher in knee than in hip. In osteogenesis experiments, the expression of COL1A1 and ALPP was significantly less in the knee synovium than in the hip synovium. Conclusions. MSCs obtained from hip joint have self-renewal and multilineage differentiation potentials. However, in matched donors, adipogenesis and osteogenesis potentials of MSCs from the knees are superior to those from the hips. Knee synovium may be a better source of MSC for potential use in hip diseases. PMID:28115945

  3. Isolation and Characterization of Synovial Mesenchymal Stem Cell Derived from Hip Joints: A Comparative Analysis with a Matched Control Knee Group.

    PubMed

    Hatakeyama, Akihisa; Uchida, Soshi; Utsunomiya, Hajime; Tsukamoto, Manabu; Nakashima, Hirotaka; Nakamura, Eiichiro; Pascual-Garrido, Cecilia; Sekiya, Ichiro; Sakai, Akinori

    2017-01-01

    Purpose. To determine the characteristics of MSCs from hip and compare them to MSCs from knee. Methods. Synovial tissues were obtained from both the knee and the hip joints in 8 patients who underwent both hip and knee arthroscopies on the same day. MSCs were isolated from the knee and hip synovial samples. The capacities of MSCs were compared between both groups. Results. The number of cells per unit weight at passage 0 of synovium from the knee was significantly higher than that from the hip (P < 0.05). While it was possible to observe the growth of colonies in all the knee synovial fluid samples, it was impossible to culture cells from any of the hip samples. In adipogenesis experiments, the frequency of Oil Red-O-positive colonies and the gene expression of adipsin were significantly higher in knee than in hip. In osteogenesis experiments, the expression of COL1A1 and ALPP was significantly less in the knee synovium than in the hip synovium. Conclusions. MSCs obtained from hip joint have self-renewal and multilineage differentiation potentials. However, in matched donors, adipogenesis and osteogenesis potentials of MSCs from the knees are superior to those from the hips. Knee synovium may be a better source of MSC for potential use in hip diseases.

  4. Comparative Phylodynamics of Rabbit Hemorrhagic Disease Virus in Australia and New Zealand

    PubMed Central

    Eden, John-Sebastian; Kovaliski, John; Duckworth, Janine A.; Swain, Grace; Mahar, Jackie E.; Strive, Tanja

    2015-01-01

    ABSTRACT The introduction of rabbit hemorrhagic disease virus (RHDV) into Australia and New Zealand during the 1990s as a means of controlling feral rabbits is an important case study in viral emergence. Both epidemics are exceptional in that the founder viruses share an origin and the timing of their release is known, providing a unique opportunity to compare the evolution of a single virus in distinct naive populations. We examined the evolution and spread of RHDV in Australia and New Zealand through a genome-wide evolutionary analysis, including data from 28 newly sequenced RHDV field isolates. Following the release of the Australian inoculum strain into New Zealand, no subsequent mixing of the populations occurred, with viruses from both countries forming distinct groups. Strikingly, the rate of evolution in the capsid gene was higher in the Australian viruses than in those from New Zealand, most likely due to the presence of transient deleterious mutations in the former. However, estimates of both substitution rates and population dynamics were strongly sample dependent, such that small changes in sample composition had an important impact on evolutionary parameters. Phylogeographic analysis revealed a clear spatial structure in the Australian RHDV strains, with a major division between those viruses from western and eastern states. Importantly, RHDV sequences from the state where the virus was first released, South Australia, had the greatest diversity and were diffuse throughout both geographic lineages, such that this region was likely a source population for the subsequent spread of the virus across the country. IMPORTANCE Most studies of viral emergence lack detailed knowledge about which strains were founders for the outbreak or when these events occurred. Hence, the human-mediated introduction of rabbit hemorrhagic disease virus (RHDV) into Australia and New Zealand from known starting stocks provides a unique opportunity to understand viral evolution

  5. High- compared to low-arched athletes exhibit smaller knee abduction moments in walking and running.

    PubMed

    Powell, Douglas W; Andrews, Samantha; Stickley, Cris; Williams, D S Blaise

    2016-12-01

    High- (HA) and low-arched athletes (LA) experience distinct injury patterns. These injuries are the result of the interaction of structure and biomechanics. A suggested mechanism of patellofemoral pain pertains to frontal plane knee moments which may be exaggerated in LA athletes. We hypothesize that LA athletes will exhibit greater peak knee abduction moments than high-arched athletes.

  6. Comparing the mechanical properties of the porcine knee meniscus when hydrated in saline versus synovial fluid.

    PubMed

    Lakes, Emily H; Kline, Courtney L; McFetridge, Peter S; Allen, Kyle D

    2015-12-16

    As research progresses to find a suitable knee meniscus replacement, accurate in vitro testing becomes critical for feasibility and comparison studies of mechanical integrity. Within the knee, the meniscus is bathed in synovial fluid, yet the most common hydration fluid in laboratory testing is phosphate buffered saline (PBS). PBS is a relatively simple salt solution, while synovial fluid is a complex non-Newtonian fluid with multiple lubricating factors. As such, PBS may interact with meniscal tissue differently than synovial fluid, and thus, the hydration fluid may be an important factor in obtaining accurate results during in vitro testing. To evaluate these effects, medial porcine menisci were used to evaluate tissue mechanics in tension (n=11) and compression (n=15). In all tests, two samples from the same meniscus were taken, where one sample was hydrated in PBS and the other was hydrated in synovial fluid. Statistical analysis revealed no significant differences between the mean mechanical properties of samples tested in PBS compared to synovial fluid; however, compressive testing revealed the variability between samples was significantly reduced if samples were tested in synovial fluid. For example, the compressive Young׳s Modulus was 12.69±7.49MPa in PBS versus 12.34±4.27MPa in synovial fluid. These results indicate testing meniscal tissue in PBS will largely not affect the mean value of the mechanical properties, but performing compression testing in synovial fluid may provide more consistent results between samples and assist in reducing sample numbers in some experiments.

  7. Comparative biochemical responses and antioxidant activities of the rabbit urinary bladder to whole grapes versus resveratrol.

    PubMed

    Francis, Johdi-Ann; Leggett, Robert E; Schuler, Catherine; Levin, Robert M

    2015-12-01

    The objective of this study is to compare the antioxidant activity of a whole-grape suspension with the antioxidant activity or pure resveratrol on the effect of hydrogen peroxide (H2O2) on malondialdehyde (MDA) generation, choline acetyltransferase (ChAT) activity, calcium ATPase activity, and sarcoendoplasmic reticular ATPase (SERCA) of the male rabbit urinary bladder. MDA was used as a model for the effect of H2O2 on lipid peroxidation. ChAT, SERCA, and calcium ATPase were evaluated based on their importance in urinary bladder physiology and pathology. Four male rabbit bladders were used. Each bladder was separated into muscle and mucosa, frozen under liquid nitrogen and stored at -80 °C for biochemical evaluation. The effect of H2O2 on the enzymes listed above was determined in the presence and absence of either resveratrol or a whole-grape suspension. (1) Resveratrol was significantly more effective than the grape suspension at protecting the bladder muscle and mucosa against peroxidation as quantitated by MDA formation. (2) The grape suspension was significantly more effective at protecting ChAT activity against oxidative stress of the muscle than resveratrol. (3) Neither the grape suspension nor resveratrol were particularly effective at protecting the bladder muscle or mucosa calcium ATPase or SERCA against oxidative stress. (4) ChAT was significantly more sensitive to oxidative stress than either calcium ATPase or SERCA. These data support the idea that the grape suspension protects the mitochondria and nerve terminals to a significantly greater degree than resveratrol which suggests that the activities of the grape suspension are due to the combination of active components found in the grape suspension and not just resveratrol alone.

  8. Comparing different data collection and analysis techniques for quantifying healthy knee joint function during stair ascent and descent.

    PubMed

    Whatling, G M; Evans, S L; Holt, C A

    2009-11-01

    There is currently no standard data collection or analysis method for the assessment of stair gait using motion analysis. This makes the comparison of results from different studies difficult. It is important to gain an appreciation of the discrepancies in kinematic and kinetic information generated by employing different computational approaches, as these differences may be critical in cases where methodologies were to change over a long-term study. This study explores the effect of using different methodologies for the assessment of non-pathological knee function of ten subjects during stair ascent and descent. Two methods of computing knee kinematics were compared: (a) using in-house software and a pointer method of anatomical calibration and (b) using commercial software, Visual3D (C-motion, Inc.) and skin-mounted markers. Significant differences were found between the two methods when calculating a frontal plane range of motion (p < 0.05). Three methods of computing knee moments were compared. Knee moments computed using the inverse dynamic analysis (IDA) approach of Visual3D (C-motion, Inc.) were significantly different (p < 0.05) to those calculated using in-house IDA software that ignores the foot and ankle and to those computed using a vector cross-product approach. This study highlights the implications of comparing data generated from different collection and analysis methods.

  9. Mobile-bearing medial unicompartmental knee arthroplasty restores limb alignment comparable to that of the unaffected contralateral limb

    PubMed Central

    Mullaji, Arun B; Shah, Siddharth; Shetty, Gautam M

    2017-01-01

    Background and purpose — Medial unicompartmental knee arthroplasty (UKA) is undertaken in patients with a passively correctable varus deformity. We investigated whether restoration of natural soft tissue tension would result in a lower limb alignment similar to that of the contralateral unaffected lower limb after mobile-bearing medial UKA. Patients and methods — In this retrospective study, hip-knee-ankle (HKA) angle, position of the weight-bearing axis (WBA), and knee joint line obliquity (KJLO) after mobile-bearing medial UKA was compared with that of the unaffected (clinically and radiologically) contralateral lower limb in 123 patients. Results — Postoperatively, HKA angle was restored to within ±3° of the contralateral lower limb in 87% of the patients and the WBA passed within ±1 Kennedy and White’s tibial zone of the unaffected contralateral lower limb in 95% of the patients. The mean KJLO in the operated limbs was not significantly different from that in the unaffected lower limbs (p = 0.07) and the KJLO in the operated limb was restored to within ±3° of that in the contralateral lower limb in 96% of the patients. Interpretation — Lower limb alignment and knee joint line obliquity after mobile-bearing medial UKA were comparable to that of the unaffected contralateral limb in most patients. Comparison with the contralateral unaffected lower limb is a reliable method for evaluation and validation of limb mechanical alignment after mobile-bearing medial UKA. PMID:27794622

  10. Runner's Knee

    MedlinePlus

    ... Surgery? A Week of Healthy Breakfasts Shyness Runner's Knee KidsHealth > For Teens > Runner's Knee A A A ... told he had runner's knee. What Is Runner's Knee? Runner's knee is the term doctors use for ...

  11. Knee pain

    MedlinePlus

    Pain - knee ... Knee pain can have different causes. Being overweight puts you at greater risk for knee problems. Overusing your knee can trigger knee problems that cause pain. If you have a history of arthritis, it ...

  12. Comparative analysis of NADPH-diaphorase positive neurons in the rat, rabbit and pheasant thoracic spinal cord. A histochemical study.

    PubMed

    Kluchová, D; Rybárová, S; Miklosová, M; Lovásová, K; Schmidtová, K; Dorko, F

    2001-01-01

    The distribution of NADPH-diaphorase (NADPH-d) activity was investigated and compared in the rat, rabbit and pheasant thoracic spinal cord. The investigation of all spinal cord regions (laminae) in three experimental species revealed marked differences in the distribution of NADPH-d activity. Cross sectional analysis of the spinal cord of the rat, rabbit and pheasant confirmed differences in the shape of the gray matter in all examined species. More detailed investigation of Rexed's laminas showed similar distribution of NADPH-d activity in the spinal cord of the rat and rabbit, which were different when compared with the spinal cord of the pheasant. Ventral horn of the rat and rabbit showed no labelling whereas in pheasant this area possessed a number of scattered, intensively stained neurons. In the location of autonomic preganglionic neurons, differences were found as well. In the rat there was seen a number of densely packed, clearly dark blue coloured neurons. Similarly, these neurons were present in the rabbit spinal cord but they were less numerous. No staining was found in this region of pheasant. Pericentral area (lamina X) and intermediate zone (laminaVII) revealed the presence of NADPH-d positive neurons in all examined species although they differed in number and shape of their bodies. The dorsal horn showed the presence of NADPH-d staining in all three animals but its distribution was different in medio-lateral direction. It can be suggested that observed differencies in the presence and distribution of NADPH-d activity across the examined species may reflect different fylogenetic development.

  13. Comparative assessment of intrinsic mechanical stimuli on knee cartilage and compressed agarose constructs.

    PubMed

    Completo, A; Bandeiras, C; Fonseca, F

    2017-03-17

    A well-established cue for improving the properties of tissue-engineered cartilage is mechanical stimulation. However, the explicit ranges of mechanical stimuli that correspond to favorable metabolic outcomes are elusive. Usually, these outcomes have only been associated with the applied strain and frequency, an oversimplification that can hide the fundamental relationship between the intrinsic mechanical stimuli and the metabolic outcomes. This highlights two important key issues: the firstly is related to the evaluation of the intrinsic mechanical stimuli of native cartilage; the second, assuming that the intrinsic mechanical stimuli will be important, deals with the ability to replicate them on the tissue-engineered constructs. This study quantifies and compares the volume of cartilage and agarose subjected to a given magnitude range of each intrinsic mechanical stimulus, through a numerical simulation of a patient-specific knee model coupled with experimental data of contact during the stance phase of gait, and agarose constructs under direct-dynamic compression. The results suggest that direct compression loading needs to be parameterized with time-dependence during the initial culture period in order to better reproduce each one of the intrinsic mechanical stimuli developed in the patient-specific cartilage. A loading regime which combines time periods of low compressive strain (5%) and frequency (0.5Hz), in order to approach the maximal principal strain and fluid velocity stimulus of the patient-specific cartilage, with time periods of high compressive strain (20%) and frequency (3Hz), in order to approach the pore pressure values, may be advantageous relatively to a single loading regime throughout the full culture period.

  14. Calcium aluminate coated and uncoated free form fabricated CoCr implants: a comparative study in rabbit.

    PubMed

    Palmquist, A; Jarmar, T; Hermansson, L; Emanuelsson, L; Taylor, A; Taylor, M; Engqvist, H; Thomsen, P

    2009-10-01

    The purpose of this study was to compare the integration in bone of uncoated free form fabricated cobalt chromium (CoCr) implants to the same implant with a calcium aluminate coating. The implants of cylindrical design with a pyramidal surface structure were press-fit into the limbs of New Zealand white rabbits. After 6 weeks, the rabbits were sacrificed, and samples were retrieved and embedded. Ground sections were subjected to histological analysis and histomorphometry. The section counter part was used for preparing an electron transparent transmission electron microscopy sample by focused ion beam milling. Calcium aluminate dip coating provided a significantly greater degree of bone contact than that of the native CoCr. The gibbsite hydrate formed in the hardening reaction of the calcium aluminate was found to be the exclusive crystalline phase material in direct contact with bone.

  15. Comparative efficacies of lipid-complexed amphotericin B and liposomal amphotericin B against coccidioidal meningitis in rabbits.

    PubMed

    Clemons, Karl V; Capilla, Javier; Sobel, Raymond A; Martinez, Marife; Tong, Ann-Jay; Stevens, David A

    2009-05-01

    In separate previous studies, we have shown that lipid-complexed amphotericin B (Abelcet [ABLC]) and liposomal amphotericin B (AmBisome [AmBi]) are efficacious against coccidioidal meningitis in rabbits. Here, we compared ABLC and AmBi directly in a coccidioidal meningitis model. Male New Zealand White rabbits were infected with 5 x 10(4) Coccidioides posadasii arthroconidia by direct cisternal puncture. Therapy with intravenous ABLC or AmBi at 7.5 or 15 mg/kg of body weight or sterile 5% dextrose water (D5W) began 5 days later. Clinical assessments were done daily; cerebrospinal fluid and blood samples were obtained on day 15 and upon euthanasia. Survivors to day 25 were euthanatized, the numbers of CFU in their tissues were determined, and histology analyses of the brains and spinal cords were done. Controls showed progressive disease, whereas animals treated with either dose of either drug showed few clinical signs of infection. All ABLC- or AmBi-treated rabbits survived, whereas eight of nine D5W-treated rabbits were euthanatized before day 25 (P < 0.0001). Numbers of CFU in the brains and spinal cords of ABLC- or AmBi-treated animals were 100- to 10,000-fold lower than those in the corresponding tissues of D5W-treated animals (P < 0.0006 to 0.0001). However, only two or fewer given a regimen of ABLC or AmBi were cured of infection in both tissues. Fewer ABLC-treated rabbits (four of eight treated with 7.5 mg/kg and five of eight treated with 15 mg/kg) than controls (nine of nine) had meningitis at any level of severity (P, 0.015 or 0.043 for animals treated with ABLC at 7.5 or 15 mg/kg, respectively). Although groups of rabbits treated with AmBi regimens did not have significantly fewer animals with meningitis than the control group (P > 0.05), ABLC and AmBi were not significantly different. In this model, intravenous ABLC and AmBi were similarly highly effective, with few clinical signs of infection, 100% survival, and significantly reduced fungal burdens

  16. Comparative assessment of knee extensor and flexor muscle strength measured using a hand-held vs. isokinetic dynamometer

    PubMed Central

    Muff, Guillaume; Dufour, Stéphane; Meyer, Alain; Severac, François; Favret, Fabrice; Geny, Bernard; Lecocq, Jehan; Isner-Horobeti, Marie-Eve

    2016-01-01

    [Purpose] To compare measurements of knee extensor and flexor muscle strength performed using a hand-held dynamometer and an isokinetic dynamometer in apparently healthy subjects. [Subjects and Methods] Thirty adult volunteers underwent knee muscle strength evaluation using an isokinetic or a hand-held dynamometer. [Results] Strong positive correlations were found between the 2 methods, with correlation coefficients r ranging from 0.72 (95% confidence interval [CI], 0.48−0.86) to 0.87 (95% CI, 0.75−0.94), depending on the muscle group and the isokinetic evaluation mode. The reproducibility of the hand-held dynamometer findings was good, judged by a coefficient of variation of 3.2–4.2%. However, the correlation between the 2 methods for the assessment of flexor/extensor ratios ranged from −0.04 to 0.46. [Conclusion] Knee extensor and flexor muscle strength recorded with a hand-held dynamometer is reproducible and significantly correlated with the isokinetic values, indicating that this method may in some cases be a useful replacement for isokinetic strength measurement. However, for strength ratio assessment, and when judged against the isokinetic standard, a hand-held dynamometer is not a valid option. PMID:27799667

  17. Comparative assessment of knee extensor and flexor muscle strength measured using a hand-held vs. isokinetic dynamometer.

    PubMed

    Muff, Guillaume; Dufour, Stéphane; Meyer, Alain; Severac, François; Favret, Fabrice; Geny, Bernard; Lecocq, Jehan; Isner-Horobeti, Marie-Eve

    2016-09-01

    [Purpose] To compare measurements of knee extensor and flexor muscle strength performed using a hand-held dynamometer and an isokinetic dynamometer in apparently healthy subjects. [Subjects and Methods] Thirty adult volunteers underwent knee muscle strength evaluation using an isokinetic or a hand-held dynamometer. [Results] Strong positive correlations were found between the 2 methods, with correlation coefficients r ranging from 0.72 (95% confidence interval [CI], 0.48-0.86) to 0.87 (95% CI, 0.75-0.94), depending on the muscle group and the isokinetic evaluation mode. The reproducibility of the hand-held dynamometer findings was good, judged by a coefficient of variation of 3.2-4.2%. However, the correlation between the 2 methods for the assessment of flexor/extensor ratios ranged from -0.04 to 0.46. [Conclusion] Knee extensor and flexor muscle strength recorded with a hand-held dynamometer is reproducible and significantly correlated with the isokinetic values, indicating that this method may in some cases be a useful replacement for isokinetic strength measurement. However, for strength ratio assessment, and when judged against the isokinetic standard, a hand-held dynamometer is not a valid option.

  18. Patterns of knee osteoarthritis in Arabian and American knees.

    PubMed

    Hodge, W Andrew; Harman, Melinda K; Banks, Scott A

    2009-04-01

    This study illustrates differences in the cartilage degeneration in osteoarthritic knees in patients with more frequent hyperflexion activities of daily living compared with Western patients. Proximal tibial articular cartilage wear and cruciate ligament condition were assessed in Saudi Arabian and North American patients with varus osteoarthritis undergoing total knee arthroplasty. In anterior cruciate ligament (ACL) intact knees, there were significant differences in wear location, with a clearly more anterior pattern in Saudi Arabian knees. Complete ACL deficiency occurred in 25% of North American knees but only 14% of Saudi Arabian knees. These ACL-deficient knees showed the most severe cartilage wear in both groups and posterior medial wear patterns. Biomechanical descriptions of knee flexion and axial rotation during kneeling or squatting are consistent with the more pronounced anteromedial and posterolateral cartilage wear patterns observed on the Saudi Arabian knees. These observations provide insight into altered knee mechanics in 2 culturally different populations with different demands on knee flexion.

  19. Comparing the effects of manual therapy versus electrophysical agents in the management of knee osteoarthritis.

    PubMed

    Ali, Syed Shahzad; Ahmed, Syed Imran; Khan, Muhammad; Soomro, Rabail Rani

    2014-07-01

    To evaluate the effectiveness of Manual Therapy in comparison to Electrophysical agents in Knee Osteoarthritis. Total 50 patients with knee osteoarthritis were recruited from OPD of orthopedics civil hospital and Institute Of Physical Medicine & Rehabilitation, Dow University of Health Sciences Karachi. All those patients who fulfilled inclusion criteria were selected on voluntary basis. Selected patients were equally divided and randomly assigned into two groups with age and gender matching. The Manual therapy group received program of Maitland joint mobilization whereas Electrophysical Agent group received a program of TENS and cold pack. Both group received a program of exercise therapy as well. Patients received 3 treatment sessions per week for 4 successive weeks. Clinical assessment was performed using WOMAC index at baseline and on 12th treatment session. Both study groups showed clinically and statistically considerable improvements in WOMAC index. However, Related 2 sample t-test showed better clinical results in Manual Therapy group (p = 0.000) than Electrophysical Agents group (p = 0.008). The mean improvement in total WOMAC index was relatively higher in Manual Therapy group (22.36 ± 13.91) than Electrophysical Agent group (9.72 ± 6.10). This study concluded that manual therapy is clinically more effective in decreasing pain, stiffness and improving physical function in knee osteoarthritis.

  20. Organic matter and macromineral digestibility in domestic rabbits (Oryctolagus cuniculus) as compared to other hindgut fermenters.

    PubMed

    Hagen, K B; Tschudin, A; Liesegang, A; Hatt, J-M; Clauss, M

    2015-12-01

    It is generally assumed that animal species differ in physiological characteristics of their digestive tract. Because investigating digestive processes is often labour-intensive, requiring lengthy adaptation and collection periods, comparisons are often made on the basis of data collated from different studies. We added a new data set on dietary crude fibre (CF) and macromineral (Na, K, Ca, P, Mg) composition and apparent digestibility (aD) of organic matter (OM) and macrominerals in rabbits (Oryctolagus cuniculus; a total of 180 measurements with 12 individuals and 10 different diets) to a literature data collection for rodents and domestic horses (Equus caballus). Significant negative relationships between dietary CF and aD OM were obtained, but the significant difference in digestive efficiency between rabbits and guinea pigs (Cavia porcellus) reported from studies where both species had been investigated under identical conditions were not detectable in the larger data collection. However, the 95% confidence interval of the negative slope of the CF-aD OM relationship did not overlap between domestic horses on the one hand, and rabbits and guinea pigs on the other hand, indicating a less depressing effect of CF in horses. Akaike's information criterion indicated that aD of a macromineral did not only depend on its concentration in the diet, but also on the individual and various other diet characteristics and the presence of other macrominerals, indicating complex interactions. The data indicate similar mechanisms in the absorption of macrominerals amongst rabbits, rodents and horses, with the exception of Na and K in guinea pigs and Ca in chinchillas (Chinchilla laniger) that should be further corroborated. In particular, the occurrence of high aD Ca in hindgut fermenters, regardless of whether they employ a digestive strategy of coprophagy or whether they have fossorial habits, suggests that this peculiarity might represent an adaptation to hindgut

  1. Comparative effects of sildenafil, phentolamine, yohimbine and L-arginine on the rabbit corpus cavernosum.

    PubMed

    Sharabi, F M; Daabees, T T; El-Metwally, M A; Senbel, A M

    2004-04-01

    Penile erection involves relaxation of smooth muscle of corpus cavernosum and associated arterioles. Sildenafil, a highly selective inhibitor of phosphodiesterase type 5, is effective in the treatment of erectile dysfunction. The aim of this study is to investigate the effect of sildenafil on smooth muscle of the rabbit corpus cavernosum (RCC) and to compare its effect with those of phentolamine, yohimbine and L-arginine. The effects of sildenafil, phentolamine, yohimbine and L-arginine were studied on the response of the RCC to electrical field stimulation (EFS) as well as on the phenylephrine (PE, 3 x 10(-6) M)-induced tone. EFS caused transient, frequency-dependent relaxation of the RCC that was inhibited by the nitric oxide synthase inhibitor NG-nitro-L-arginine (3 x 10(-5) M). Sildenafil (1 x 10(-9)-1 x 10(-6) M) and phentolamine (1 x 10(-9)-1 x 10(-6) M) enhanced the EFS-induced relaxation in a concentration-dependent manner with ED50 of 0.056 +/- 0.004 and 0.572 +/-0.035 microM at 8 Hz, respectively, yohimbine (3 x 10(-7)-3 x 10(-5) M) and L-arginine (3 x 10(-6)-3 x 10(-4) M) did not show significant effects (ED50 at 8 Hz = 35.84 +/-2.24 and 2.164 +/- 0.174 microM, respectively). Sildenafil (1 x 10(-9) and 1 x 10(-8) M) potentiated the EFS-induced relaxation caused by L-arginine (3 x 10(-5) m). Sildenafil, phentolamine, yohimbine and L-arginine reduced the PE-induced tone to different extents; the ED50 values were 0.81 +/- 0.097, 0.49 +/- 0.025 and 13.97 +/- 1.10 microM, respectively. Maximum concentration of L-arginine used failed to produce 50% relaxation (ED20 = 221.82 +/- 15.71 microM). The muscle relaxant effects of different combinations of sildenafil and L-arginine on PE-induced tone did not differ significantly from the sum of the individual effects. The results demonstrate that sildenafil, when compared to other drugs used in penile erection dysfunction, shows the highest potency on the nitrergic transmission in the RCC. On the other hand

  2. Cost-effectiveness analysis of arthroscopic surgery compared with non-operative management for osteoarthritis of the knee

    PubMed Central

    Marsh, Jacquelyn D; Birmingham, Trevor B; Giffin, J Robert; Isaranuwatchai, Wanrudee; Hoch, Jeffrey S; Feagan, Brian G; Litchfield, Robert; Willits, Kevin; Fowler, Peter

    2016-01-01

    Objective To determine the cost-effectiveness of arthroscopic surgery in addition to non-operative treatments compared with non-operative treatments alone in patients with knee osteoarthritis (OA). Design, setting and participants We conducted an economic evaluation alongside a single-centre, randomised trial among patients with symptomatic, radiographic knee OA (KL grade ≥2). Interventions Patients received arthroscopic debridement and partial resection of degenerative knee tissues in addition to optimised non-operative therapy, or optimised non-operative therapy only. Main outcome measures Direct and indirect costs were collected prospectively over the 2-year study period. The effectiveness outcomes were the Western Ontario McMaster Osteoarthritis Index (WOMAC) and quality-adjusted life years (QALYs). Cost-effectiveness was estimated using the net benefit regression framework considering a range of willingness-to-pay values from the Canadian public payer and societal perspectives. We calculated incremental cost-effectiveness ratios and conducted sensitivity analyses using the extremes of the 95% CIs surrounding mean differences in effect between groups. Results 168 patients were included. Patients allocated to arthroscopy received partial resection and debridement of degenerative meniscal tears (81%) and/or articular cartilage (97%). There were no significant differences between groups in use of non-operative treatments. The incremental net benefit was negative for all willingness-to-pay values. Uncertainty estimates suggest that even if willing to pay $400 000 to achieve a clinically important improvement in WOMAC score, or ≥$50 000 for an additional QALY, there is <20% probability that the addition of arthroscopy is cost-effective compared with non-operative therapies only. Our sensitivity analysis suggests that even when assuming the largest treatment effect, the addition of arthroscopic surgery is not economically attractive compared with non

  3. Comparative study on isokinetic capacity of knee and ankle joints by functional injury

    PubMed Central

    Jeon, Kyoungkyu; Seo, Byoung-Do; Lee, Sang-Ho

    2016-01-01

    [Purpose] To collect basic data for exercise programs designed to enhance functional knee and ankle joint stability based on isokinetic measurement and muscle strength evaluations in normal and impaired functional states. [Subjects and Methods] Twenty-four subjects were randomly assigned to the athlete group and the control group (n = 12 each). Data were collected of isokinetic knee extensor and flexor strength at 60°/sec, 180°/sec, and 240°/sec and ankle plantar and dorsiflexor strength at 30°/sec and 120°/sec. [Results] Significant intergroup differences were observed in peak torque of the right extensors at 60°/sec, 180°/sec, and 240°/sec and the right flexors at 240°/sec. Significant differences were observed in peak torque/body weight in the right extensors at 60°/sec, 180°/sec, and 240°/sec and in the right flexors at 180°/sec and 240°/sec. Significant peak torque differences were noted in the left ankle joint dorsiflexor at 30°/sec and 120°/sec, right plantar flexor at 120°/sec, left plantar flexor at 30°/sec, left dorsiflexor at 30°/sec and 120°/sec, and right dorsiflexor at 120°/sec. [Conclusion] Isokinetic evaluation stimulates muscle contraction at motion-dependent speeds and may contribute to the development of intervention programs to improve knee and ankle joint function and correct lower-extremity instability. PMID:26957768

  4. Comparative pharmacokinetics of (/sup 65/Zn)zinc sulfate and (/sup 65/Zn)zinc pantothenate injected intravenously in rabbits

    SciTech Connect

    Guillard, O.; Courtois, P.; Murai, P.; Ducassou, D.; Reiss, D.

    1984-11-01

    The pharmacokinetics of zinc sulfate were compared with those of a new zinc salt, pantothenate, in rabbits. Each salt was administered at a dosage of 3.3 microCi of zinc-65/kg of body weight. The measured pharmacokinetics of the two compounds responded to a two-compartment open model. The urinary elimination of the two salts was similar, as was their localization in the skin and fur, but zinc pantothenate was fixed by the liver to a lesser extent than was zinc sulfate.

  5. Comparative study of tilidine-naloxone and pentazocine in knee and hip osteoarthritis.

    PubMed

    Van Cauwenberge, H; Ruhwiedel, M; Albert, A; Franchimont, P

    1992-01-01

    Fifty patients, twenty-five suffering from severe knee osteoarthritis and twenty-five from acute hip osteoarthritis, received pentazocine or a new preparation of tilidine-naloxone for a period of 2 weeks, in a double-blind study. The two drugs were found to have the same efficacy and tolerance in both diseases with a minor but not statistically significant superiority for tilidine-naloxone. Similar quantities of drugs were taken over the study period, while patients were allowed to take as many as 8 capsules per day to relieve pain. There were quite equivalent side-effects and no marked changes in laboratory tests.

  6. Three-dimensional component alignment and functional outcome in computer-navigated total knee arthroplasty: a prospective, randomized study comparing two navigation systems.

    PubMed

    Harvie, Paul; Sloan, Karen; Beaver, Richard J

    2011-12-01

    Computer navigation in total knee arthroplasty produces better component alignment than conventional techniques. Different navigation systems exist. We undertook a prospective, randomized study comparing 2 navigations systems (Stryker Full Navigation and Stryker Articular Surface Mounted [ASM] navigation systems). Three-dimensional component alignment (Perth computed tomographic knee protocol) and function at 1 year (Knee Society Scores) were assessed. Forty patients participated (20 fully navigated and 20 ASM-navigated total knee arthroplasties). Cohorts were well matched according to sex, age, and body mass index. No statistically significant difference was seen in any parameter of 3-dimensional component alignment or function between cohorts. Operative time for the ASM cohort was significantly less than the fully navigated cohort (P = .001). Both systems performed equally well, and therefore, surgeon preference should determine which system is used.

  7. Alterations in walking knee joint stiffness in individuals with knee osteoarthritis and self-reported knee instability.

    PubMed

    Gustafson, Jonathan A; Gorman, Shannon; Fitzgerald, G Kelley; Farrokhi, Shawn

    2016-01-01

    Increased walking knee joint stiffness has been reported in patients with knee osteoarthritis (OA) as a compensatory strategy to improve knee joint stability. However, presence of episodic self-reported knee instability in a large subgroup of patients with knee OA may be a sign of inadequate walking knee joint stiffness. The objective of this work was to evaluate the differences in walking knee joint stiffness in patients with knee OA with and without self-reported instability and examine the relationship between walking knee joint stiffness with quadriceps strength, knee joint laxity, and varus knee malalignment. Overground biomechanical data at a self-selected gait velocity was collected for 35 individuals with knee OA without self-reported instability (stable group) and 17 individuals with knee OA and episodic self-reported instability (unstable group). Knee joint stiffness was calculated during the weight-acceptance phase of gait as the change in the external knee joint moment divided by the change in the knee flexion angle. The unstable group walked with lower knee joint stiffness (p=0.01), mainly due to smaller heel-contact knee flexion angles (p<0.01) and greater knee flexion excursions (p<0.01) compared to their knee stable counterparts. No significant relationships were observed between walking knee joint stiffness and quadriceps strength, knee joint laxity or varus knee malalignment. Reduced walking knee joint stiffness appears to be associated with episodic knee instability and independent of quadriceps muscle weakness, knee joint laxity or varus malalignment. Further investigations of the temporal relationship between self-reported knee joint instability and walking knee joint stiffness are warranted.

  8. Evolution of knee kinematics three months after total knee replacement.

    PubMed

    Alice, Bonnefoy-Mazure; Stéphane, Armand; Yoshisama, Sagawa Junior; Pierre, Hoffmeyer; Domizio, Suvà; Hermes, Miozzari; Katia, Turcot

    2015-02-01

    In patients with debilitating knee osteoarthritis, total knee replacement is the most common surgical procedure. Numerous studies have demonstrated that knee kinematics one year after total knee replacement are still altered compared to the healthy joint. However, little is known regarding impairments and functional limitations of patients several months after total knee replacement. The aim of this study was to describe the evolution of the knee gait kinematic in patients with knee osteoarthritis before and three months after a total knee replacement. Ninety patients who were to undergo total knee replacement were included in this study. Twenty-three subjects were recruited as the control group. Three-dimensional gait analysis was performed before and three months after surgery. The spatio-temporal parameters and three-dimensional knee kinematics for the operated limb were evaluated during a comfortable gait and compared between groups (the before and after surgery groups and the control group). Three months after surgery, patients always walk with a slower gait velocity and lower knee flexion-extension movements compared to the control group. However, a degree of progress was observed in term of the stride and step length, gait velocity and knee alignment in the coronal plane. Our results suggest that the disability is still significant for most patients three months after total knee replacement. A better understand of the impairments and functional limitations following surgery would help clinicians design rehabilitation programs. Moreover, patients should be informed that rehabilitation after total knee replacement is a long process.

  9. Cost Analysis and Surgical Site Infection Rates in Total Knee Arthroplasty Comparing Traditional vs. Single-Use Instrumentation.

    PubMed

    Siegel, Geoffrey W; Patel, Neil N; Milshteyn, Michael A; Buzas, David; Lombardo, Daniel J; Morawa, Lawrence G

    2015-12-01

    Surgical site infections (SSIs) are a significant complications in total knee arthroplasty (TKA). The purpose of this study was to evaluate if traditional vs. single-use instrumentation had an effect on SSI's. We compared SSI rates and costs of TKAs performed with single-use (449) and traditional (169) TKA instrumentation trays. Total OR Time was, on average, 30 min less when single-use instrumentation was used. SSIs decreased in the single-use group (n=1) compared to the traditional group (n=5) (P=0.006). Single-use instrumentation added $490 in initial costs; however it saved between $480 and $600. Single-use instrumentation may provide a benefit to the patient by potentially decreasing the risk of infection and reducing the overall hospital costs.

  10. Preferential influx and decreased fractional loss of lipoprotein(a) in atherosclerotic compared with nonlesioned rabbit aorta.

    PubMed Central

    Nielsen, L B; Stender, S; Jauhiainen, M; Nordestgaard, B G

    1996-01-01

    The aim was to investigate the atherogenic potential of lipoprotein(a) (Lp(a)) and to further our understanding of the atherogenic process by measuring rates of transfer into the intima-inner media (i.e., intimal clearance) and rates of loss from the intima-inner media (i.e., fractional loss) of Lp(a) and LDL using cholesterol-fed rabbits with nonlesioned (n = 13) or atherosclerotic aortas (n = 12). In each rabbit, 131I-Lp(a) (or 131I-LDL) was injected intravenously 26 h before and 125I-Lp(a) (or 125I-LDL) 3 h before the aorta was removed and divided into six consecutive segments of similar size. The intimal clearance of Lp(a) and LDL was similar and markedly increased in atherosclerotic compared with nonlesioned aortas (ANOVA, effect of atherosclerosis: P < 0.0001). Fractional losses of labeled Lp(a) and labeled LDL in atherosclerotic aorta were on average 25 and 43%, respectively, of that in nonlesioned aortas (ANOVA, effect of atherosclerosis: P < 0.0001). Fractional loss of Lp(a) was 73% of that of LDL (ANOVA, effect of type of lipoprotein: P = 0.07). These data suggest that the development of atherosclerosis is associated with increased influx as well as decreased fractional loss of Lp(a) and LDL from the intima. Accordingly, Lp(a) may share with LDL the potential for causing atherosclerosis. PMID:8755669

  11. Comparative Effects of Periarticular Multimodal Drug Injection and Single-Shot Femoral Nerve Block on Pain Following Total Knee Arthroplasty and Factors Influencing Their Effectiveness

    PubMed Central

    Nakagawa, Shuji; Inoue, Hiroaki; Kan, Hiroyuki; Hino, Manabu; Ichimaru, Shohei; Ikoma, Kazuya; Fujiwara, Hiroyoshi; Amaya, Fumimasa; Sawa, Teiji; Kubo, Toshikazu

    2016-01-01

    Purpose This study compared the analgesic effects of local infiltration analgesia (LIA) and femoral nerve block (FNB) after total knee arthroplasty (TKA) and assessed factors associated with analgesia obtained by these two methods. Materials and Methods Study subjects included 66 patients (72 knees) who underwent TKA for osteoarthritis of the knee. Pain visual analogue scale (VAS), the amount of analgesics used, number of days to achieve 90° of flexion of the knee joint, date of initiating parallel-bar walking, range of motion of the knee joint at discharge, and adverse events were investigated. Results The VAS scores did not differ significantly between two groups, whereas the amount of analgesics used was significantly lower in the LIA group. Preoperative flexion contracture was significantly more severe in the LIA group with high VAS compared with low VAS. No serious adverse event occurred in the LIA or FNB group. Conclusions The lower analgesic usage in the LIA group than the FNB group indicates that the analgesic effect of LIA was greater than that of singleshot FNB after TKA. There were no serious complications in either group. The postoperative analgesic effect of LIA was smaller in patients with severe than less severe preoperative flexion contracture. PMID:27595078

  12. The combined therapy with chondroitin sulfate plus glucosamine sulfate or chondroitin sulfate plus glucosamine hydrochloride does not improve joint damage in an experimental model of knee osteoarthritis in rabbits.

    PubMed

    Roman-Blas, Jorge A; Mediero, Aránzazu; Tardío, Lidia; Portal-Nuñez, Sergio; Gratal, Paula; Herrero-Beaumont, Gabriel; Largo, Raquel

    2017-01-05

    Osteoarthritis is the most common chronic joint disorder especially during aging. Although with controversies, glucosamine, both in its forms of sulfate and hydrochloride, and chondroitin sulfate are commonly employed to treat osteoarthritis. Due to the modest improve in the symptoms observed in patients treated with these drugs alone, a formulation combining both agents has been considered. The discrepant results achieved for pain control or structural improvement in osteoarthritis patients has been attributed to the quality of chemical formulations or different bias in clinical studies. The current study has been designed to test the effects of two different combined formulations with adequate pharmaceutical grade of these drugs in osteoarthritic joints, and to explore the underlying mechanisms modulated by both formulations in different osteoarthritis target tissues. Knee osteoarthritis was surgically induced in experimental rabbits. Some animals received the combined therapy (CT)1, (chondroitin sulfate 1200mg/day + glucosamine sulfate 1500mg/day), or the CT2 ((chondroitin sulfate 1200mg/day + glucosamine hydrochloride 1500mg/day). Neither CT1 nor CT2 significantly modified the cartilage damage or the synovial inflammation observed in osteoarthritic animals. Treatments were also unable to modify the presence of pro-inflammatory mediators, and the synthesis of metalloproteinases in the cartilage or in the synovium of osteoarthritic animals. Combined therapies did not modify the decrease in the subchondral bone mineral density observed in osteoarthritic rabbits. Therapies of chondroitin sulfate plus glucosamine sulfate or chondroitin sulfate plus glucosamine hydrochloride failed to improve structural damage or to ameliorate the inflammatory profile of joint tissues during experimental osteoarthritis.

  13. Lipid metabolism abnormalities in alcohol-treated rabbits: a morphometric and haematologic study comparing high and low alcohol doses

    PubMed Central

    Ikemura, Satoshi; Yamamoto, Takuaki; Motomura, Goro; Iwasaki, Kenyu; Yamaguchi, Ryosuke; Zhao, Garida; Iwamoto, Yukihide

    2011-01-01

    The pathogenesis of alcohol-induced osteonecrosis remains unclear. The purpose of the present study was to evaluate the morphological changes in bone marrow fat cells and the changes in the serum lipid levels in alcohol-treated rabbits. Fifteen rabbits were randomly assigned into three groups: Four rabbits intragastrically received low-dose alcohol (LDA) (15 ml/kg per day) containing 15% ethanol for 4 weeks, five rabbits received high-dose alcohol (HDA) (30 ml/kg per day) for 4 weeks and six rabbits received physiologic saline for 4 weeks as a control group. Six weeks after the initial alcohol administration, all rabbits were sacrificed. The mean size of the bone marrow fat cells in rabbits treated with HDA was significantly larger than that in the control group (P = 0.0001). Haematologically, the levels of triglycerides and free fatty acids in the rabbits treated with both low-dose and HDA were significantly higher than those in the control group (P = 0.001 for both comparisons). The results of this study are that there are lipid metabolism abnormalities, both morphologically and haematologically, after alcohol administration. Also these findings were more apparent in rabbits treated with HDA than those treated with LDA. PMID:21645143

  14. Lymphatic drainage of the skull base: comparative anatomic and advanced imaging studies in the rabbit and human with implications for spread of nasopharyngeal carcinoma.

    PubMed

    Qiuhang, Z; Zhenlin, W; Yan, Q; Jun, H; Yongfeng, S; Bo, H

    2010-09-01

    This preliminary study investigated the lymphatic drainage and distribution of lymphatic structures in the skull base. Characteristics of the rabbit skull base were analyzed and compared correspondingly with those of the human skull. The lymphatic circulation in the rabbit cranial base was detected by digital subtraction angiography (DSA), and lymph drainage in the human skull base was illustrated by interstitial magnetic resonance lymphography (MRL). Lymphatic structures and their distribution in MRL were identified by comparing with contrast-enhanced MRI and clinical data on basilar metastasis of nasopharyngeal carcinoma (NPC) in the human skull base. Anatomic similarity was found between the rabbit and human basilar regions. Well-visualized lymphatic pathways were found in the rabbit cranial base, and human lymphatic structures showed high signal intensity in enhanced T1-weighted MRL images. Lymphatic tissues in the human basilar region were found mainly distributed in the areas of the jugular foramen, foramen lacerum, and petrosal section of the internal carotid artery (ICA). Their distribution in the human basilar region was similar to the distribution in the rabbit basilar region and consistent with our clinical findings of the predilection sites of NPC metastasis in the skull base. Our studies show that bilateral symmetrical lymphatic structures were distributed along the ICA, internal jugular vein, and dura of cranial base in the central part of the middle and posterior skull base.

  15. Diagnostic performance of volume and limited oblique MRI of the anterior cruciate ligament compared to knee arthroscopy

    PubMed Central

    Richards, Paula J.; McCall, Iain; Kraus, Alexandra; Jones, Mary; Maffulli, Gayle; Bridgman, Stephen; Maffulli, Nicola

    2016-01-01

    Summary Background Many strategies have been used to improve the visualisation of the ACL including sagittal, coronal oblique sequences, and 3D volume imaging. Nevertheless, the ACL may not always be visualised. Methods Two hundred and thirty-one consecutive patients (77 females; 154 males; average age 43.5, range 18 to 82 years; 205 with chronic, 20 acute, and 6 acute on chronic symptoms) underwent knee arthroscopy for mechanical symptoms within a week of MRI. After routine orthogonal sequences, if general MRI radiographers, with over four years experience, were not able to identify the presence of the ACL, then two 3D volume sequences and 2D limited sagittal oblique T1 sequences were performed. Patients requiring extra sequences, missed by the radiography technicians, were recalled. The MRI sequences were evaluated in a blinded fashion by three radiologists, and compared to the knee arthroscopy findings, with the normal ACL acting as internal controls. The radiography technicians performed additional ACL sequences in 63 patients (27%); of these, 10 patients had a partial and 12 patients had a complete ACL tear. Only 2 patients (0.6%) were recalled (one with a normal, and one with a full thickness ACL tear). Results The filmed ACL evaluation for complete tears and a normal ACL had a sensitivity of 100%, specificity of 97.1% and accuracy of 97.3%, slightly higher than evaluating on the monitor. Volume sequences had specificities and accuracies over 95%, with good intraobserver reliability (Kappa 0.859, 95% CI 0.705–1.0). Experienced radiographers identified most cases requiring supplementary MRI ACL sequences. An additional volume sequence was beneficial when filmed. Use of the monitor can offer some benefits. Limited oblique T1 sequence of the intercondylar notch was unreliable. PMID:27900295

  16. Comparative study of the ability of mesenchymal stem cells derived from bone marrow, periosteum, and adipose tissue in treatment of partial growth arrest in rabbit.

    PubMed

    Hui, James H P; Li, Li; Teo, Yee-Hong; Ouyang, Hong-Wei; Lee, Eng-Hin

    2005-01-01

    This study evaluates the ability of MSCs isolated from different origins--bone marrow, periosteum, or fat--to treat partial growth arrest in immature (6-week-old) New Zealand White rabbits. Up to 50% of the medial half of the proximal physis of the tibia was excised in these New Zealand White rabbits. Three weeks later, the bony bridge was excised, and fibrin glue with and without MSCs were transferred into the physeal defect of different rabbits. Contralateral tibias, without undergoing operation, served as self-control. Four groups of rabbits were involved in the study. Each group was injected separately with bone marrow-derived MSCs (group I), periosteum-derived MSCs (group II), fat-derived MSCs (group III), and fibrin glue alone (control, group IV). The rabbits were killed 8 and 16 weeks postoperatively. Clinical, radiological, and histological analyses were subsequently performed. Similar proliferative rates for three MSCs were demonstrated on days 4, 7, and 11 of primary culture. However, MSCs derived from bone-marrow and periosteum appeared to be more homogeneous than that from fat. All MSCs demonstrated chondrogenic and osteogenic differentiation potentials in vitro. The tibias in groups I and II showed significant correction of varus angulation at 16 weeks. However, the varus angulation in group III remained significantly obvious when compared with group I (p < 0.05). The length discrepancies between operated and normal tibiae in groups I, II, and III were significantly corrected compared with control (p < 0.01). In conclusion, bone-marrow and periosteum yielded more homogenous MSCs than fat, providing better correction of physeal arrest in rabbits. The source of MSCs itself could influence the success in the treatment of growth arrest.

  17. A New Method for Xenogeneic Bone Graft Deproteinization: Comparative Study of Radius Defects in a Rabbit Model

    PubMed Central

    Lei, Pengfei; Sun, Rongxin; Wang, Long; Zhou, Jialin; Wan, Lifei; Zhou, Tianjian; Hu, Yihe

    2015-01-01

    Background and Objectives Deproteinization is an indispensable process for the elimination of antigenicity in xenograft bones. However, the hydrogen peroxide (H2O2) deproteinized xenograft, which is commonly used to repair bone defect, exhibits limited osteoinduction activity. The present study was designed to develop a new method for deproteinization and compare the osteogenic capacities of new pepsin deproteinized xenograft bones with those of conventional H2O2 deproteinized ones. Methods Bones were deproteinized in H2O2 or pepsin for 8 hours. The morphologies were compared by HE staining. The content of protein and collagen I were measured by the Kjeldahl method and HPLC-MS, respectively. The physical properties were evaluated by SEM and mechanical tests. For in vivo study, X-ray, micro-CT and HE staining were employed to monitor the healing processes of radius defects in rabbit models transplanted with different graft materials. Results Compared with H2O2 deproteinized bones, no distinct morphological and physical changes were observed. However, pepsin deproteinized bones showed a lower protein content, and a higher collagen content were preserved. In vivo studies showed that pepsin deproteinized bones exhibited better osteogenic performance than H2O2 deproteinized bones, moreover, the quantity and quality of the newly formed bones were improved as indicated by micro-CT analysis. From the results of histological examination, the newly formed bones in the pepsin group were mature bones. Conclusions Pepsin deproteinized xenograft bones show advantages over conventional H2O2 deproteinized bones with respect to osteogenic capacity; this new method may hold potential clinical value in the development of new biomaterials for bone grafting. PMID:26719896

  18. Platelet-Rich Plasma May Improve Osteochondral Donor Site Healing in a Rabbit Model

    PubMed Central

    Smyth, Niall A.; Haleem, Amgad M.; Ross, Keir A.; Hannon, Charles P.; Murawski, Christopher D.; Do, Huong T.; Kennedy, John G.

    2016-01-01

    Purpose The purpose of this study was to assess the effect(s) of platelet-rich plasma (PRP) on osteochondral donor site healing in a rabbit model. Methods Osteochondral donor sites 3 mm in diameter and 5 mm in depth were created bilaterally on the femoral condyles of 12 New Zealand White rabbits. Knees were randomized such that one knee in each rabbit received an intra-articular injection of PRP and the other received saline (placebo). Rabbits were euthanized at 3, 6, and 12 weeks following surgery. Repair tissue was evaluated using the International Cartilage Repair Society (ICRS) macroscopic and histological scores. Results No complications occurred as a result of the interventions. There was no significant difference in macroscopic scores between the 2 groups (5.5 ± 3.8 vs. 3.8 ± 3.5; P = 0.13). Subjective macroscopic assessment determined greater tissue infill with fewer fissures and a more cartilage-like appearance in PRP-treated knees. Overall ICRS histological scores were better in the PRP group compared with the placebo (9.8 ± 2.0 vs. 7.8 ± 1.8; P = 0.04). Histological scores were also higher in the PRP group compared with the placebo group at each time point. Greater glycosaminoglycan and type II collagen content were noted in the repair tissue of the PRP group compared with the placebo group. Conclusion The results of this study indicate that PRP used as an intra-articular injection may improve osteochondral healing in a rabbit model. PMID:26958322

  19. Rabbit medicine.

    PubMed

    Jordan, Dinah G

    2007-01-01

    When filling prescriptions for a rabbit, it is important to know whether the rabbit is a pet or is being raised as a source of food for human consumption. Several drugs widely used for pet rabbits are prohibited from exralabel use in animals raised for food production. The list of banned drugs should always be perused prior to filling a prescription for a rabbit being raised for food production. Since no veterinary-approved products exist for rabbits and most medications must be compounded, pharmacists are likely to encounter prescriptions for rabbits in their practice. A basic understanding of rabbit anatomy, physiolgy and common diseases will assist pharmacists in distinguishing between safe and dangerous drugs for administration to rabbits.

  20. Five-year results of a randomised controlled trial comparing mobile and fixed bearings in total knee replacement.

    PubMed

    Breeman, S; Campbell, M K; Dakin, H; Fiddian, N; Fitzpatrick, R; Grant, A; Gray, A; Johnston, L; MacLennan, G S; Morris, R W; Murray, D W

    2013-04-01

    There is conflicting evidence about the merits of mobile bearings in total knee replacement, partly because most randomised controlled trials (RCTs) have not been adequately powered. We report the results of a multicentre RCT of mobile versus fixed bearings. This was part of the knee arthroplasty trial (KAT), where 539 patients were randomly allocated to mobile or fixed bearings and analysed on an intention-to-treat basis. The primary outcome measure was the Oxford Knee Score (OKS) plus secondary measures including Short Form-12, EuroQol EQ-5D, costs, cost-effectiveness and need for further surgery. There was no significant difference between the groups pre-operatively: mean OKS was 17.18 (sd 7.60) in the mobile-bearing group and 16.49 (sd 7.40) in the fixed-bearing group. At five years mean OKS was 33.19 (sd 16.68) and 33.65 (sd 9.68), respectively. There was no significant difference between trial groups in OKS at five years (-1.12 (95% confidence interval -2.77 to 0.52) or any of the other outcome measures. Furthermore, there was no significant difference in the proportion of patients with knee-related re-operations or in total costs. In this appropriately powered RCT, over the first five years after total knee replacement functional outcomes, re-operation rates and healthcare costs appear to be the same irrespective of whether a mobile or fixed bearing is used.

  1. Disposable rabbit

    DOEpatents

    Lewis, Leroy C.; Trammell, David R.

    1986-01-01

    A disposable rabbit for transferring radioactive samples in a pneumatic transfer system comprises aerated plastic shaped in such a manner as to hold a radioactive sample and aerated such that dissolution of the rabbit in a solvent followed by evaporation of the solid yields solid waste material having a volume significantly smaller than the original volume of the rabbit.

  2. Disposal rabbit

    DOEpatents

    Lewis, L.C.; Trammell, D.R.

    1983-10-12

    A disposable rabbit for transferring radioactive samples in a pneumatic transfer system comprises aerated plastic shaped in such a manner as to hold a radioactive sample and aerated such that dissolution of the rabbit in a solvent followed by evaporation of the solid yields solid waste material having a volume significantly smaller than the original volume of the rabbit.

  3. Platelet-rich plasma increases transforming growth factor-beta1 expression at graft-host interface following autologous osteochondral transplantation in a rabbit model

    PubMed Central

    Boakye, Lorraine A; Ross, Keir A; Pinski, John M; Smyth, Niall A; Haleem, Amgad M; Hannon, Charles P; Fortier, Lisa A; Kennedy, John G

    2015-01-01

    AIM: To explore the effect of platelet-rich plasma on protein expression patterns of transforming growth factor-beta1 (TGF-β1) in cartilage following autologous osteochondral transplantation (AOT) in a rabbit knee cartilage defect model. METHODS: Twelve New Zealand white rabbits received bilateral AOT. In each rabbit, one knee was randomized to receive an autologous platelet rich plasma (PRP) injection and the contralateral knee received saline injection. Rabbits were euthanized at 3, 6 and 12 wk post-operatively. Articular cartilage sections were stained with TGF-β1 antibody. Histological regions of interest (ROI) (left, right and center of the autologous grafts interfaces) were evaluated using MetaMorph. Percentage of chondrocytes positive for TGF-β1 was then assessed. RESULTS: Percentage of chondrocytes positive for TGF-β1 was higher in PRP treated knees for selected ROIs (left; P = 0.03, center; P = 0.05) compared to control and was also higher in the PRP group at each post-operative time point (P = 6.6 × 10-4, 3.1 × 10-4 and 7.3 × 10-3 for 3, 6 and 12 wk, respectively). TGF-β1 expression was higher in chondrocytes of PRP-treated knees (36% ± 29% vs 15% ± 18%) (P = 1.8 × 10-6) overall for each post-operative time point and ROI. CONCLUSION: Articular cartilage of rabbits treated with AOT and PRP exhibit increased TGF-β1 expression compared to those treated with AOT and saline. Our findings suggest that adjunctive PRP may increase TGF-β1 expression, which may play a role in the chondrogenic effect of PRP in vivo. PMID:26716092

  4. Kinematic and kinetic analysis of a stepping-in-place task in below-knee amputee children compared to able-bodied children.

    PubMed

    Centomo, Hugo; Amarantini, David; Martin, Luc; Prince, François

    2007-06-01

    It has been demonstrated that below-knee amputee (BKA) subjects use specific compensation strategies to overcome their physical limitations. Biomechanical studies emphasize that the motor strategies adopted by BKA adults differ between their amputated limb and their nonamputated limb and from those employed by able-bodied (AB) subjects. The purpose of this investigation was to compare the motor solutions used by control AB and BKA children during a stepping-in-place (SIP) task and to assess how they regulate the coordination of their nonamputated and amputated limbs during this task. Eight BKA children and eight AB children paired for gender, age, weight and height participated in our study. One-way analysis of variances (ANOVAs) were performed on peaks of angular excursion, moment, and power at the hip, knee, and ankle to compare motor strategies between the BKA and AB groups. The main results of our experiment showed that even if BKA and AB children did the task with almost the same kinematics, the kinetic data revealed completely different mechanisms of the two groups to achieve the SIP task, and BKA children had a symmetrical interlimb strategy. SIP, a simple task compared to gait at the level of neuro-musculoskeletal demands, could thus offer a transition task to physical therapists for below-knee recently-amputated children.

  5. Ocular pharmacokinetics of bimatoprost formulated in DuraSite compared to bimatoprost 0.03% ophthalmic solution in pigmented rabbit eyes

    PubMed Central

    Shafiee, Afshin; Bowman, Lyle M; Hou, Eddie; Hosseini, Kamran

    2013-01-01

    Purpose To compare the aqueous humor (AH) and iris-ciliary body (ICB) concentration of bimatoprost in rabbit eyes treated with ISV-215 (0.03% bimatoprost formulated in DuraSite) with the marketed product bimatoprost 0.03% ophthalmic solution. Methods The left eye of rabbits received a single topical instillation of either ISV-215 (n = 32 eyes) or bimatoprost 0.03% (n = 32 eyes). At predetermined time points, levels of bimatoprost and bimatoprost acid in the AH and the ICB were quantified by HPLC-MS/MS. Results Both bimatoprost and bimatoprost acid were detected in the AH and the ICB within 15 minutes of dosing. Bimatoprost acid concentrations in both compartments were markedly higher than bimatoprost. There was a statistically significant (P < 0.01) increase in the concentration of the prodrug in the AH and its acid form in the ICB in animals treated with ISV-215 compared to bimatoprost 0.03%. In the ISV-215-treated rabbit eyes, the highest concentrations of bimatoprost and bimatoprost acid were in the ICB and AH, respectively, while in the bimatoprost 0.03%-treated eyes, no differences in the drug content of the selected ocular tissues were observed. Conclusions Bimatoprost 0.03% formulated in DuraSite has superior ocular distribution and area under the curve compared to bimatoprost 0.03% in rabbit eyes. This improvement in the pharmacokinetic parameters of ISV-215 may provide us with a better platform to optimize a bimatoprost formulation that offers the same degree of efficacy in lowering intraocular pressure and improved therapeutic index in glaucomatous patients by lessening the ocular side effects associated with long-term use of topical prostaglandin F2α analogs. PMID:23940414

  6. Comparative effectiveness of a complex Ayurvedic treatment and conventional standard care in osteoarthritis of the knee – study protocol for a randomized controlled trial

    PubMed Central

    2013-01-01

    -effectiveness continuum. Discussion This trial is the first to compare the effectiveness of a complex Ayurvedic intervention with a complex conventional intervention in a Western medical setting in patients with knee osteoarthritis. During the trial design, aspects of efficacy and effectiveness were discussed. The resulting design is a compromise between rigor and pragmatism. Trial registration NCT01225133 PMID:23701973

  7. Clinical efficacy of intra-articular injections in knee osteoarthritis: a prospective randomized study comparing hyaluronic acid and betamethasone

    PubMed Central

    Trueba Davalillo, Cesáreo Ángel; Trueba Vasavilbaso, Cesáreo; Navarrete Álvarez, José Mario; Coronel Granado, Pilar; García Jiménez, Ozcar Alejandro; Gimeno del Sol, Mercedes; Gil Orbezo, Félix

    2015-01-01

    Background Osteoarthritis (OA) is the most common joint disease and leading cause of disability. Intra-articular (IA) administration of hyaluronic acid (HA) or corticosteroids (CS) have been previously studied, though using insufficient number of patients or short follow-up periods. Objective We evaluate HA and CS in patients with knee OA in terms of clinical efficacy over 12 months. Methods We used a prospective, randomized study with parallel groups. Randomized patients received IA injections of HA or betamethasone (BM). The primary outcomes were improvement in pain using Visual Analog Scale and function in the Western Ontario and McMaster University Osteoarthritis Index (Likert scale). Follow-up visits were scheduled at 3 months, 6 months, 9 months, and 12 months. Results A total of 200 patients were included. Pain was significantly reduced in both groups at the first follow-ups. At 12 months, the mean pain reduction in the HA group was 33.6% (95% CI: 31.1–36.1) compared to 8.2% (95% CI: 5.2–11.1) in BM (P<0.0001). Function improvement was higher in HA through every visit, and mean improvement at 12 months was 47.5% (95% CI: 45.6–49.3) in HA patients vs 13.2% (95% CI: 11.4–14.9) in the BM group (P<0.0001). All patients from both groups achieved the Minimal Clinically Important Improvement (MCII) for both pain and function up to 6 months. At 9 months and 12 months, the MCII figures were higher in HA group with ≥80% compared to ≤10% in BM group (P<0.0001). Adverse reactions were rare and related to the administration procedure. Conclusion Both treatments effectively controlled OA symptoms. BM showed higher short-term effectiveness, while HA showed better long-term effectiveness, maintaining clinical efficacy in a large number of patients 1 year after administration. PMID:27790040

  8. A new ambulatory system for comparative evaluation of the three-dimensional knee kinematics, applied to anterior cruciate ligament injuries.

    PubMed

    Favre, J; Luthi, F; Jolles, B M; Siegrist, O; Najafi, B; Aminian, K

    2006-07-01

    The aim of this study was to develop an ambulatory system for the three-dimensional (3D) knee kinematics evaluation, which can be used outside a laboratory during long-term monitoring. In order to show the efficacy of this ambulatory system, knee function was analysed using this system, after an anterior cruciate ligament (ACL) lesion, and after reconstructive surgery. The proposed system was composed of two 3D gyroscopes, fixed on the shank and on the thigh, and a portable data logger for signal recording. The measured parameters were the 3D mean range of motion (ROM) and the healthy knee was used as control. The precision of this system was first assessed using an ultrasound reference system. The repeatability was also estimated. A clinical study was then performed on five unilateral ACL-deficient men (range: 19-36 years) prior to, and a year after the surgery. The patients were evaluated with the IKDC score and the kinematics measurements were carried out on a 30 m walking trial. The precision in comparison with the reference system was 4.4 degrees , 2.7 degrees and 4.2 degrees for flexion-extension, internal-external rotation, and abduction-adduction, respectively. The repeatability of the results for the three directions was 0.8 degrees , 0.7 degrees and 1.8 degrees . The averaged ROM of the five patients' healthy knee were 70.1 degrees (standard deviation (SD) 5.8 degrees), 24.0 degrees (SD 3.0 degrees) and 12.0 degrees (SD 6.3 degrees for flexion-extension, internal-external rotation and abduction-adduction before surgery, and 76.5 degrees (SD 4.1 degrees), 21.7 degrees (SD 4.9 degrees) and 10.2 degrees (SD 4.6 degrees) 1 year following the reconstruction. The results for the pathologic knee were 64.5 degrees (SD 6.9 degrees), 20.6 degrees (SD 4.0 degrees) and 19.7 degrees (8.2 degrees) during the first evaluation, and 72.3 degrees (SD 2.4 degrees), 25.8 degrees (SD 6.4 degrees) and 12.4 degrees (SD 2.3 degrees) during the second one. The performance of the

  9. Efficacy and safety of topical diclofenac containing dimethyl sulfoxide (DMSO) compared with those of topical placebo, DMSO vehicle and oral diclofenac for knee osteoarthritis.

    PubMed

    Simon, Lee S; Grierson, Lisa M; Naseer, Zahid; Bookman, Arthur A M; Zev Shainhouse, J

    2009-06-01

    While topical non-steroidal anti-inflammatory drugs are considered safe, their long-term efficacy for osteoarthritis has been suspect. We conducted a 12-week, double-blind, double-dummy, randomized controlled trial of topical diclofenac (TDiclo) in a vehicle solution containing dimethyl sulfoxide (DMSO) in 775 subjects with radiologically confirmed, symptomatic primary osteoarthritis of the knee. This 5-arm study compared TDiclo with a placebo solution, the DMSO vehicle, oral diclofenac (ODiclo) and the combination of TDiclo+ODiclo for relieving the signs and symptoms of knee osteoarthritis. Subjects applied study solution, 40 drops four times daily, and took one study tablet daily for 12 weeks. Co-primary efficacy variables were WOMAC pain and physical function and a patient overall health assessment. Secondary variables were WOMAC stiffness and patient global assessment (PGA) of the knee osteoarthritis. TDiclo was superior to placebo for pain (-6.0 vs. -4.7, P=0.015), physical function (-15.8 vs. -12.3, P=0.034), overall health (-0.95 vs. -0.37, P<0.0001), and PGA (-1.36 vs. -1.01, P=0.016), and was superior to DMSO vehicle for all efficacy variables. No significant difference was observed between DMSO vehicle and placebo or between TDiclo and ODiclo. The commonest adverse event associated with TDiclo was dry skin (18.2%). Fewer digestive system and laboratory abnormalities were observed with TDiclo than with ODiclo. Addition of TDiclo to ODiclo did not increase the incidence of systemic adverse events. TDiclo in DMSO vehicle is an effective treatment option for knee osteoarthritis with efficacy similar to, but tolerability better than ODiclo. DMSO vehicle was no more efficacious than placebo.

  10. Greater glucose uptake heterogeneity in knee muscles of old compared to young men during isometric contractions detected by [(18)F]-FDG PET/CT.

    PubMed

    Rudroff, Thorsten; Kindred, John H; Benson, John-Michael; Tracy, Brian L; Kalliokoski, Kari K

    2014-01-01

    We used positron emission tomography/computed tomography (PET/CT) and [(18)F]-FDG to test the hypothesis that glucose uptake (GU) heterogeneity in skeletal muscles as a measure of heterogeneity in muscle activity is greater in old than young men when they perform isometric contractions. Six young (26 ± 6 years) and six old (77 ± 6 years) men performed two types of submaximal isometric contractions that required either force or position control. [(18)F]-FDG was injected during the task and PET/CT scans were performed immediately after the task. Within-muscle heterogeneity of knee muscles was determined by calculating the coefficient of variation (CV) of GU in PET image voxels within the muscles of interest. The average GU heterogeneity (mean ± SD) for knee extensors and flexors was greater for the old (35.3 ± 3.3%) than the young (28.6 ± 2.4%) (P = 0.006). Muscle volume of the knee extensors were greater for the young compared to the old men (1016 ± 163 vs. 598 ± 70 cm(3), P = 0.004). In a multiple regression model, knee extensor muscle volume was a predictor (partial r = -0.87; P = 0.001) of GU heterogeneity for old men (R (2) = 0.78; P < 0.001), and MVC force predicted GU heterogeneity for young men (partial r = -0.95, P < 0.001). The findings demonstrate that GU is more spatially variable for old than young men and especially so for old men who exhibit greater muscle atrophy.

  11. Jumper's Knee (Patellar Tendonitis)

    MedlinePlus

    ... Surgery? A Week of Healthy Breakfasts Shyness Jumper's Knee KidsHealth > For Teens > Jumper's Knee A A A ... continued damage to the knee. How Does the Knee Work? To understand how jumper's knee happens, it ...

  12. Knee arthroscopy - series (image)

    MedlinePlus

    ... knee problems such as: a torn knee disc (meniscus) a damaged knee bone (patella) a damaged ligament ... surgeon can see the ligaments, the knee disc (meniscus), the knee bone (patella), the lining of the ...

  13. [Cemented total knee replacement: comparative study between the use or not of tourniquet on the inmediate results].

    PubMed

    Gutiérrez-García, J A; Sierra-Pérez, M; García-Velazco, R A; Salas-Mora, C A; Cisneros-González, V M

    2016-01-01

    Comparison of immediate postoperative results of patients undergoing cemented total knee arthroplasty with and without ischemia. Observational, cross-sectional, retrospective, analytical, single-center study that included 180 patients who underwent total knee arthroplasty from 2011 to 2014: 120 without ischemia, 60 with ischemia. Mean age was 70 years with SD ± 7. Criteria to assess the immediate postoperative results include intraoperative bleeding, hemoglobin differential and pain. Exclusion criteria comprised patients being treated at a pain clinic, those on anticoagulants, with a history of bleeding disorders, psychiatric conditions, kidney failure or those intolerant to NSAIDs. In total knee arthroplasty without ischemia there is better pain control (p = 0.026). The hemoglobin differential and intraoperative bleeding were less with ischemia (p = 0.008). 32.8% of patients required blood transfusion, but no statistically significant relationship was established with the use or non-use of ischemia (p = 0.301). The most commonly reported pain was within a VAS of 0-3; 62.2% of cases reported mild pain. Mean hemoglobin differential was 3.7 with SD ± 1.3 with a range from 0 to 7.4. Patients in whom no ischemia was used during the surgical procedure experienced less pain. There was less bleeding and hemoglobin differential with the use of ischemia. However, this did not result in a statistically significant difference in the need for blood transfusion. The use of ischemia with caution and according to the surgeons preference is recommended.

  14. Comparative assessment of knee joint models used in multi-body kinematics optimisation for soft tissue artefact compensation.

    PubMed

    Richard, Vincent; Cappozzo, Aurelio; Dumas, Raphaël

    2017-01-31

    Estimating joint kinematics from skin-marker trajectories recorded using stereophotogrammetry is complicated by soft tissue artefact (STA), an inexorable source of error. One solution is to use a bone pose estimator based on multi-body kinematics optimisation (MKO) embedding joint constraints to compensate for STA. However, there is some debate over the effectiveness of this method. The present study aimed to quantitatively assess the degree of agreement between reference (i.e., artefact-free) knee joint kinematics and the same kinematics estimated using MKO embedding six different knee joint models. The following motor tasks were assessed: level walking, hopping, cutting, running, sit-to-stand, and step-up. Reference knee kinematics was taken from pin-marker or biplane fluoroscopic data acquired concurrently with skin-marker data, made available by the respective authors. For each motor task, Bland-Altman analysis revealed that the performance of MKO varied according to the joint model used, with a wide discrepancy in results across degrees of freedom (DoFs), models and motor tasks (with a bias between -10.2° and 13.2° and between -10.2mm and 7.2mm, and with a confidence interval up to ±14.8° and ±11.1mm, for rotation and displacement, respectively). It can be concluded that, while MKO might occasionally improve kinematics estimation, as implemented to date it does not represent a reliable solution to the STA issue.

  15. A comparative study of the bone contact to zirconium and titanium implants after 8 weeks of implantation in rabbit femoral condyles.

    PubMed

    AlFarraj, Abdullah Aldosari; Sukumaran, Anil; Amri Al, D Mohammad; Van Oirschot, Aja Bart; Jansen, John A

    2017-02-13

    Zirconium (Zr) has been found to have comparable characteristics to titanium with a favorable modulus of elasticity. In addition, the release of Zr-ions of a Zr implant is supposed to further increase the bone-to-implant response. Therefore, the objective of this study is to compare the bone contact to Zr and Ti implants in the femoral trabecular bone of rabbits. In addition, implants provided with a hydroxyapatite (HA) coating were included, as such a coating was proven before to enhance the secondary implant stability. A total of 32 implants consisting of 16 Zr (8 HA coated) and 16 Ti (8 HA coated) implants were installed in the femoral condyle of 16 rabbits. After 8 weeks of healing the femoral condyles including the implants were retrieved and studied histologically. The bone-to-implant contact (BIC) percentage was assessed and analyzed statistically. The BIC values of the uncoated Zr and Ti implants showed comparable BIC values (45.1 ± 14.8 vs. 45.5 ± 13.1). The BIC percentage was slightly higher for HA coated Zr and Ti implants (60.3 ± 17.1, 59.8 ± 16.4, respectively) compared to uncoated, but statistical testing indicated that this difference was not significant. It can be concluded that Zr and Ti implants show a comparable bone-implant contact after 8 weeks of implantation in the currently used rabbit model. In addition, the deposition of a sputtered HA coating on both Zr and Ti implants did not further improve their bone integration.

  16. Runner's Knee

    MedlinePlus

    ... name just two. It's the most common overuse injury among runners, but it can also strike other athletes who do activities that require a lot of knee bending, such as biking, jumping, or skiing. Runner's knee happens when the kneecap (patella) tracks incorrectly over a ...

  17. Intraoperative passive kinematics of osteoarthritic knees before and after total knee arthroplasty.

    PubMed

    Siston, Robert A; Giori, Nicholas J; Goodman, Stuart B; Delp, Scott L

    2006-08-01

    Total knee arthroplasty is a successful procedure to treat pain and functional disability due to osteoarthritis. However, precisely how a total knee arthroplasty changes the kinematics of an osteoarthritic knee is unknown. We used a surgical navigation system to measure normal passive kinematics from 7 embalmed cadaver lower extremities and in vivo intraoperative passive kinematics on 17 patients undergoing primary total knee arthroplasty to address two questions: How do the kinematics of knees with advanced osteoarthritis differ from normal knees?; and, Does posterior substituting total knee arthroplasty restore kinematics towards normal? Osteoarthritic knees displayed a decreased screw-home motion and abnormal varus/valgus rotations between 10 degrees and 90 degrees of knee flexion when compared to normal knees. The anterior-posterior motion of the femur in osteoarthritic knees was not different than in normal knees. Following total knee arthroplasty, we found abnormal varus/valgus rotations in early flexion, a reduced screw-home motion when compared to the osteoarthritic knees, and an abnormal anterior translation of the femur during the first 60 degrees of flexion. Posterior substituting total knee arthroplasty does not appear to restore normal passive varus/valgus rotations or the screw motion and introduces an abnormal anterior translation of the femur during intraoperative evaluation.

  18. Superior results with eccentric compared to concentric quadriceps training in patients with jumper's knee: a prospective randomised study

    PubMed Central

    Jonsson, P; Alfredson, H

    2005-01-01

    Background: A recent study reported promising clinical results using eccentric quadriceps training on a decline board to treat jumper's knee (patellar tendinosis). Methods: In this prospective study, athletes (mean age 25 years) with jumper's knee were randomised to treatment with either painful eccentric or painful concentric quadriceps training on a decline board. Fifteen exercises were repeated three times, twice daily, 7 days/week, for 12 weeks. All patients ceased sporting activities for the first 6 weeks. Age, height, weight, and duration of symptoms were similar between groups. Visual analogue scales (VAS; patient estimation of pain during exercise) and Victorian Institute of Sport Assessment (VISA) scores, before and after treatment, and patient satisfaction, were used for evaluation. Results: In the eccentric group, for 9/10 tendons patients were satisfied with treatment, VAS decreased from 73 to 23 (p<0.005), and VISA score increased from 41 to 83 (p<0.005). In the concentric group, for 9/9 tendons patients were not satisfied, and there were no significant differences in VAS (from 74 to 68, p<0.34) and VISA score (from 41 to 37, p<0.34). At follow up (mean 32.6 months), patients in the eccentric group were still satisfied and sports active, but all patients in the concentric group had been treated surgically or by sclerosing injections. Conclusions: In conclusion, eccentric, but not concentric, quadriceps training on a decline board, seems to reduce pain in jumper's knee. The study aimed to include 20 patients in each group, but was stopped at the half time control because of poor results achieved in the concentric group. PMID:16244196

  19. Comparative toxicities and pharmacokinetics of intrathecal lipid (amphotericin B colloidal dispersion) and conventional deoxycholate formulations of amphotericin B in rabbits.

    PubMed

    Clemons, K V; Sobel, R A; Williams, P L; Stevens, D A

    2001-02-01

    The lipid formulation of amphotericin B, Amphotec (ABCD), has not been used intrathecally. After a single intrathecal dose or after four doses, conventionally formulated deoxycholate amphotericin B (AMB) (Fungizone) resulted in higher levels of amphotericin B in the cerebrospinal fluid of rabbits than did ABCD. Clinically and histologically, ABCD was about threefold less toxic than AMB after a single dose and 3- to 30-fold less toxic after multiple dosing. These data are encouraging for the potential use of ABCD as an intrathecal treatment.

  20. Comparative metabolism of codeine in man, rat, dog, guinea-pig and rabbit: identification of four new metabolites.

    PubMed

    Cone, E J; Darwin, W D; Gorodetzky, C W

    1979-05-01

    The metabolism and excretion of codeine and its metabolites in untreated urine of man, rat, dog, guinea-pig and rabbit have been examined. Metabolites were identified by gas chromatography mass spectrometry operated in the chemical ionization mode (methane). Concentrations of codeine and metabolites were measured by selected ion monitoring. Both codeine and norcodeine were detected in the urine of all species but a new metabolite, hydrocodone, was found only in the urine from man, guinea-pig and dog. Additional metabolites (presumably resulting from the metabolism of hydrocodone) were also detected in man and guinea-pig. Overall recoveries of drug and metabolites from untreated urine were low for all species.

  1. Comparative Toxicities and Pharmacokinetics of Intrathecal Lipid (Amphotericin B Colloidal Dispersion) and Conventional Deoxycholate Formulations of Amphotericin B in Rabbits

    PubMed Central

    Clemons, Karl V.; Sobel, Raymond A.; Williams, Paul L.; Stevens, David A.

    2001-01-01

    The lipid formulation of amphotericin B, Amphotec (ABCD), has not been used intrathecally. After a single intrathecal dose or after four doses, conventionally formulated deoxycholate amphotericin B (AMB) (Fungizone) resulted in higher levels of amphotericin B in the cerebrospinal fluid of rabbits than did ABCD. Clinically and histologically, ABCD was about threefold less toxic than AMB after a single dose and 3- to 30-fold less toxic after multiple dosing. These data are encouraging for the potential use of ABCD as an intrathecal treatment. PMID:11158765

  2. Efficacy and immunogenicity of single-dose AdVAV intranasal anthrax vaccine compared to anthrax vaccine absorbed in an aerosolized spore rabbit challenge model.

    PubMed

    Krishnan, Vyjayanthi; Andersen, Bo H; Shoemaker, Christine; Sivko, Gloria S; Tordoff, Kevin P; Stark, Gregory V; Zhang, Jianfeng; Feng, Tsungwei; Duchars, Matthew; Roberts, M Scot

    2015-04-01

    AdVAV is a replication-deficient adenovirus type 5-vectored vaccine expressing the 83-kDa protective antigen (PA83) from Bacillus anthracis that is being developed for the prevention of disease caused by inhalation of aerosolized B. anthracis spores. A noninferiority study comparing the efficacy of AdVAV to the currently licensed Anthrax Vaccine Absorbed (AVA; BioThrax) was performed in New Zealand White rabbits using postchallenge survival as the study endpoint (20% noninferiority margin for survival). Three groups of 32 rabbits were vaccinated with a single intranasal dose of AdVAV (7.5 × 10(7), 1.5 × 10(9), or 3.5 × 10(10) viral particles). Three additional groups of 32 animals received two doses of either intranasal AdVAV (3.5 × 10(10) viral particles) or intramuscular AVA (diluted 1:16 or 1:64) 28 days apart. The placebo group of 16 rabbits received a single intranasal dose of AdVAV formulation buffer. All animals were challenged via the inhalation route with a targeted dose of 200 times the 50% lethal dose (LD50) of aerosolized B. anthracis Ames spores 70 days after the initial vaccination and were followed for 3 weeks. PA83 immunogenicity was evaluated by validated toxin neutralizing antibody and serum anti-PA83 IgG enzyme-linked immunosorbent assays (ELISAs). All animals in the placebo cohort died from the challenge. Three of the four AdVAV dose cohorts tested, including two single-dose cohorts, achieved statistical noninferiority relative to the AVA comparator group, with survival rates between 97% and 100%. Vaccination with AdVAV also produced antibody titers with earlier onset and greater persistence than vaccination with AVA.

  3. Comparative studies for ciprofloxacin hydrochloride pre-formed gels and thermally triggered (in situ) gels: in vitro and in vivo appraisal using a bacterial keratitis model in rabbits.

    PubMed

    Abdelkader, Hamdy; Mansour, Heba F

    2015-06-01

    This article reports on comparative in vitro characterization and in vivo evaluation of pre-formed cellulose-based gels, methylcellulose (MC) and carboxymethylcellulose sodium (CMC) and in situ gel-forming Pluronic F127 (PL) for ocular delivery of ciprofloxacin hydrochloride (Cipro) by using a bacterial keratitis model and histological corneal examination. Drug-polymer interactions were studied employing thermal analysis. Further, different concentrations (1-3% w/w or 10-30% w/w) of gels depending on the nature of the polymer used were prepared, characterized for clarity, pH, rheology and in vitro release. Selected gel formulations were evaluated for ocular delivery to Staphylococcus aureus-infected rabbit corneas; and ocular toxicity through histological examination of the cornea. The results demonstrated no Cipro-polymers physicochemical interactions and pseudoplastic flow for all gels used at 35 °C. Both polymer concentrations and drug solubility in the gels are dominantly the rate-determining factors for in vitro drug release. The corneal healing rate for all gel-based formulations was significantly faster (p < 0.05) than that for Cipro solution-treated rabbits. PL-based gel induced significant swelling/edema of the corneal stroma, compared with MC- and CMC-based gels. In conclusion, cellulose-based polymers have superior ocular tolerability/dramatically less irritant; and superior efficacy with more convenient administration compared with PL and Cipro solution, respectively.

  4. Comparative effects of clarithromycin on action potential and ionic currents from rabbit isolated atrial and ventricular myocytes.

    PubMed

    Gluais, Pascale; Bastide, Michìle; Caron, Jacques; Adamantidis, Monique

    2003-04-01

    Prolongation of QT interval by several antibacterial drugs is an unwanted side effect that may be associated with development of ventricular arrhythmias. The macrolide antibacterial agent clarithromycin has been shown to cause QT prolongation. To determine the electrophysiologic basis for this arrhythmogenic potential, we investigated clarithromycin effects on (i). action potentials recorded from rabbit Purkinje fibers and atrial and ventricular myocardium using conventional microelectrodes and (ii). potassium and calcium currents recorded from rabbit atrial and ventricular isolated myocytes using whole-cell patch clamp recordings. We found that (i). clarithromycin (3-100 microM) exerted concentration-dependent lengthening effects on action potential duration in all tissues, with higher efficacy and reverse frequency-dependence in Purkinje fibers. However, clarithromycin did not cause development of early afterdepolarizations, and the parameters other than action potential duration were almost unaffected; (ii). clarithromycin (10-100 microM) reduced the delayed rectifier current. Significant blockade (approximately 30%) was found at the concentration of 30 microM. At 100 microM, it decreased significantly the maximum peak of the calcium current amplitude but failed to alter the transient outward and inwardly rectifier currents. It was concluded that these effects might be an explanation for the QT prolongation observed in some patients treated with clarithromycin.

  5. Comparing the Predictive Value of Task Performance and Task-Specific Sensitivity During Physical Function Testing Among People With Knee Osteoarthritis.

    PubMed

    Wideman, Timothy H; Edwards, Robert R; Finan, Patrick H; Haythornthwaite, Jennifer A; Smith, Michael T

    2016-05-01

    Study Design Cross-sectional cohort. Background Knee osteoarthritis (OA) is a leading cause of pain and mobility restriction. Past research has advocated the use of brief, functional tasks to evaluate these restrictions, such as the six-minute-walk test and the timed up-and-go test. Typically, only task performance (ie, walking distance, completion time) is used to inform clinical practice. Recent research, however, suggests that individual variance in how people feel while completing these tasks (ie, task sensitivity) might also have important clinical value. Objective To compare the predictive value of task performance and task-specific sensitivity in determining OA-related physical function (measured by the Western Ontario and McMaster Universities Osteoarthritis Index) and pain-related interference (measured by the Multidimensional Pain Inventory). Methods One hundred eight participants with chronic knee OA completed the six-minute-walk test and the timed up-and-go test, and reported levels of discomfort and affective response (mood) associated with each test. Results In separate regression models, both task performance and task-specific sensitivity predicted OA-related physical function and pain-related interference. A final regression model including all significant predictors showed that task-specific sensitivity (specifically, post-six-minute-walk discomfort) emerged as a unique predictor of both outcomes. Conclusion These findings highlight the value of a novel clinical assessment strategy for patients with knee OA. While clinicians commonly focus on how patients perform on standardized functional tasks, these results highlight the value of also considering levels of posttask sensitivity. Measures of task-specific sensitivity relate to Maitland's concept of pain irritability, which may be a useful framework for future research on sensitizing factors and pain-related disability. J Orthop Sports Phys Ther 2016;46(5):346-356. Epub 21 Mar 2016. doi:10

  6. The Healing Effect of Adipose-Derived Mesenchymal Stem Cells in Full-thickness Femoral Articular Cartilage Defects of Rabbit

    PubMed Central

    Mehrabani, D.; Babazadeh, M.; Tanideh, N.; Zare, S.; Hoseinzadeh, S.; Torabinejad, S.; Koohi-Hosseinabadi, O.

    2015-01-01

    Background: Articular cartilage defect can lead to degradation of subchondral bone and osteoarthritis (OA). Objective: To determine the healing effect of transplantation of adipose-derived mesenchymal stem cells (Ad-MSCs) in full-thickness femoral articular cartilage defects in rabbit. Methods: 12 rabbits were equally divided into cell-treated and control groups. In cell-treated group, 2×106 cells of third passage suspended in 1 mL of DMEM was injected into articular defect. The control group just received 1 mL of DMEM. Dulbecco’s modified Eagles medium (DMEM) supplemented with 10% fetal bovine serum (FBS), 1% penicillin and streptomycin and 2 mM L-glutamine were used for cell culture. To induce cartilage defect, 4 mm articular cartilage full-thickness defect was created in the knee. For histological evaluation in each group (H&E, safranin-O and toluidine blue), 3 rabbits were sacrificed 4 weeks and 3 animals, 8 weeks after cell transplantation. Results: In cell therapy group post-transplantation, no abnormal gross findings were noticed. Neo-formed tissues in cell-treated groups were translucent with a smooth and intact surface and less irregularity. In cell-treated group after 8 weeks post-transplantation, the overall healing score of experimental knees were superior when compared to other groups. Conclusion: We showed that Ad-MSCs, as an available and non-invasive produced source of cells, could be safely administered in knee osteochondral defects. PMID:26576262

  7. Knee Injuries

    MedlinePlus

    ... keeping it from bending outward. anterior cruciate ligament (ACL): The ACL connects your femur to your tibia at the ... Common knee sprains usually involve damage to the ACL and/or MCL. The most serious sprains involve ...

  8. Knee MRI

    MedlinePlus

    ... of the knee uses a powerful magnetic field, radio waves and a computer to produce detailed pictures of ... scans, MRI does not utilize ionizing radiation. Instead, radio waves redirect alignment of hydrogen atoms that naturally exist ...

  9. Knee Dislocations

    PubMed Central

    Schenck, Robert C.; Richter, Dustin L.; Wascher, Daniel C.

    2014-01-01

    Background: Traumatic knee dislocation is becoming more prevalent because of improved recognition and increased exposure to high-energy trauma, but long-term results are lacking. Purpose: To present 2 cases with minimum 20-year follow-up and a review of the literature to illustrate some of the fundamental principles in the management of the dislocated knee. Study Design: Review and case reports. Methods: Two patients with knee dislocations who underwent multiligamentous knee reconstruction were reviewed, with a minimum 20-year follow-up. These patients were brought back for a clinical evaluation using both subjective and objective measures. Subjective measures include the following scales: Lysholm, Tegner activity, visual analog scale (VAS), Short Form–36 (SF-36), International Knee Documentation Committee (IKDC), and a psychosocial questionnaire. Objective measures included ligamentous examination, radiographic evaluation (including Telos stress radiographs), and physical therapy assessment of function and stability. Results: The mean follow-up was 22 years. One patient had a vascular injury requiring repair prior to ligament reconstruction. The average assessment scores were as follows: SF-36 physical health, 52; SF-36 mental health, 59; Lysholm, 92; IKDC, 86.5; VAS involved, 10.5 mm; and VAS uninvolved, 2.5 mm. Both patients had excellent stability and were functioning at high levels of activity for their age (eg, hiking, skydiving). Both patients had radiographic signs of arthritis, which lowered 1 subject’s IKDC score to “C.” Conclusion: Knee dislocations have rare long-term excellent results, and most intermediate-term studies show fair to good functional results. By following fundamental principles in the management of a dislocated knee, patients can be given the opportunity to function at high levels. Hopefully, continued advances in the evaluation and treatment of knee dislocations will improve the long-term outcomes for these patients in the

  10. Comparative studies on neutralisation of primary HIV-1 isolates by human sera and rabbit anti-V3 peptide sera.

    PubMed

    Lawoko, A L; Johansson, B; Hjalmarsson, S; Christensson, B; Ljungberg, B; Al-Khalili, L; Sjölund, M; Pipkorn, R; Fenyö, E M; Blomberg, J

    1999-10-01

    IgG binding to V3 peptides and serum neutralising responses were studied in four HIV-1 infected individuals with progressive disease over a period of 31-70 months. The 18-20 mer peptides comprised residues 299-317 (numbering of HIV1 MN) in the N-terminal half of the V3 loop of the envelope glycoprotein gp120 and were derived from the sequences of autologous, as well as heterologous isolates. All four individuals studied lacked anti-V3 IgG binding to at least one autologous V3 sequence. V3 peptides to which autologous sera lacked binding IgG were all immunogenic in rabbits and induced antisera that were broadly cross-reactive by EIA and broadly cross-neutralising to primary HIV-1 isolates. This indicates that the peptides are immunogenic per se and that the respective human hosts have selective defects in recognising the corresponding V3 sequences. Despite the absence of antibody binding to autologous V3 peptides, the human sera had neutralising antibodies to autologous (three out of four cases), as well as heterologous isolates (all cases). Moreover, in vitro exposure of the patients' isolates to autologous neutralising serum or the homologous rabbit antiserum selected for variants with amino acid substitutions close to the crown of the V3 loop or in regions outside the sequence corresponding to peptides used for immunisation. The amino acid exchanges affected V3 positions known to be antigenic and which are also prone to change successively in infected persons. It is likely that neutralising antibodies recognise both linear and conformational epitopes in the V3 loop. Apparently, there are several, but restricted, numbers of ways for this structure to change its conformation and thereby give rise to neutralisation resistant viruses.

  11. Systematic Review and Comparative Meta-Analysis of Outcomes Following Pedicled Muscle versus Fasciocutaneous Flap Coverage for Complex Periprosthetic Wounds in Patients with Total Knee Arthroplasty

    PubMed Central

    Economides, James M.; DeFazio, Michael V.; Golshani, Kayvon; Cinque, Mark; Anghel, Ersilia L.; Attinger, Christopher E.

    2017-01-01

    Background In cases of total knee arthroplasty (TKA) threatened by potential hardware exposure, flap-based reconstruction is indicated to provide durable coverage. Historically, muscle flaps were favored as they provide vascular tissue to an infected wound bed. However, data comparing the performance of muscle versus fasciocutaneous flaps are limited and reflect a lack of consensus regarding the optimal management of these wounds. The aim of this study was to compare the outcomes of muscle versus fasciocutaneous flaps following the salvage of compromised TKA. Methods A systematic search and meta-analysis were performed to identify patients with TKA who underwent either pedicled muscle or fasciocutaneous flap coverage of periprosthetic knee defects. Studies evaluating implant/limb salvage rates, ambulatory function, complications, and donor-site morbidity were included in the comparative analysis. Results A total of 18 articles, corresponding to 172 flaps (119 muscle flaps and 53 fasciocutaneous flaps) were reviewed. Rates of implant salvage (88.8% vs. 90.1%, P=0.05) and limb salvage (89.8% vs. 100%, P=0.14) were comparable in each cohort. While overall complication rates were similar (47.3% vs. 44%, P=0.78), the rates of persistent infection (16.4% vs. 0%, P=0.14) and recurrent infection (9.1% vs. 4%, P=0.94) tended to be higher in the muscle flap cohort. Notably, functional outcomes and ambulation rates were sparingly reported. Conclusions Rates of limb and prosthetic salvage were comparable following muscle or fasciocutaneous flap coverage of compromised TKA. The functional morbidity associated with muscle flap harvest, however, may support the use of fasciocutaneous flaps for coverage of these defects, particularly in young patients and/or high-performance athletes. PMID:28352601

  12. In-vivo alignment comparing patient specific instrumentation with both conventional and computer assisted surgery (CAS) instrumentation in total knee arthroplasty.

    PubMed

    Barrett, William; Hoeffel, Daniel; Dalury, David; Mason, J Bohannon; Murphy, Jeff; Himden, Sam

    2014-02-01

    Patient specific instrumentation (PSI) was developed to increase total knee arthroplasty (TKA) accuracy and efficiency. The study purpose was to compare immediate post-operative mechanical alignment, achieved using PSI, with conventional and computer assisted surgery (CAS) instruments in high volume TKA practices. This prospective, multicenter, non-randomized study accrued 66 TKA patients using PSI. A computed tomography (CT) based algorithm was used to develop the surgical plan. Sixty-two percent were females, 99% were diagnosed with osteoarthritis, average age at surgery was 66 years, and 33 was the average body mass index. A historical control group was utilized that underwent TKA using conventional instruments (n=86) or CAS (n=81), by the same set of surgeons. Postoperative mechanical alignment was comparable across the groups. Operative time mean and variance were significant.

  13. Randomized controlled trial comparing hyaluronic acid, platelet-rich plasma and the combination of both in the treatment of mild and moderate osteoarthritis of the knee.

    PubMed

    Lana, José F S D; Weglein, Adam; Sampson, Steve E; Vicente, Eduardo F; Huber, Stephany Cares; Souza, Clarissa V; Ambach, Mary A; Vincent, Hunter; Urban-Paffaro, Aline; Onodera, Carolina M K; Annichino-Bizzacchi, Joyce M; Santana, Maria Helena A; Belangero, William D

    2016-01-01

    Objective: This study aims at evaluating the clinical effects of Platelet Rich Plasma (PRP) and Hyaluronic Acid (HA) as individual treatments for mild to moderate Osteoarthritis (OA) and it also examines the potential synergistic effects of PRP in combination with HA. Research continues to emerge examining the potential therapeutic efficacy of HA and PRP as autologous injectable treatments for joint arthritis. However, there is a paucity of research investigating the effects of combining HA and PRP on pain and functional status in patients with OA. Design: In this multi-center, randomized, controlled, double blind, prospective trial, 105 patients with mild to moderate knee osteoarthritis, who met the study criteria, were randomly allocated to one of three interventions: HA (n=36), PRP (n=36), or HA+PRP (n=33). Each patient received 3 intra-articular knee injections of their assigned substance, with 2 week intervals between each injection. Clinical outcomes were evaluated using the Western Ontario and McMaster Universities Arthritis Index (WOMAC) and Visual Analogue Scale (VAS) questionnaire at baseline and after 1,3,6 and 12 months. Results: The study showed that the PRP group have significant reduction in VAS scores at 1 (p= 0.003), 3 (p= 0.0001), 6 (p= 0.0001) and 12 (p= 0.000) months when compared to HA. In addition, the PRP group illustrated greater improvement in WOMAC physical activity scale at 12 months (p= 0.008) when compared to the HA group. Combining HA and PRP resulted in a significant decreases in pain (p=0.0001) and functional limitation (p=0.0001) when compared to HA alone at 1 year post treatment; and significantly increased physical function at 1 (p=0.0004) and 3 (p=.011) months when compared to PRP alone. Conclusion: The findings of the study support the use of autologous PRP as an effective treatment of mild to moderate knee osteoarthritis. It also shows that the combination of HA and PRP resulted to better outcomes than HA alone up to 1 year and

  14. Randomized controlled trial comparing hyaluronic acid, platelet-rich plasma and the combination of both in the treatment of mild and moderate osteoarthritis of the knee

    PubMed Central

    Lana, José F. S. D.; Weglein, Adam; Sampson, Steve E.; Vicente, Eduardo F.; Huber, Stephany Cares; Souza, Clarissa V.; Ambach, Mary A.; Vincent, Hunter; Urban-Paffaro, Aline; Onodera, Carolina M. K.; Annichino-Bizzacchi, Joyce M.; Santana, Maria Helena A.; Belangero, William D.

    2016-01-01

    Objective: This study aims at evaluating the clinical effects of Platelet Rich Plasma (PRP) and Hyaluronic Acid (HA) as individual treatments for mild to moderate Osteoarthritis (OA) and it also examines the potential synergistic effects of PRP in combination with HA. Research continues to emerge examining the potential therapeutic efficacy of HA and PRP as autologous injectable treatments for joint arthritis. However, there is a paucity of research investigating the effects of combining HA and PRP on pain and functional status in patients with OA. Design: In this multi-center, randomized, controlled, double blind, prospective trial, 105 patients with mild to moderate knee osteoarthritis, who met the study criteria, were randomly allocated to one of three interventions: HA (n=36), PRP (n=36), or HA+PRP (n=33). Each patient received 3 intra-articular knee injections of their assigned substance, with 2 week intervals between each injection. Clinical outcomes were evaluated using the Western Ontario and McMaster Universities Arthritis Index (WOMAC) and Visual Analogue Scale (VAS) questionnaire at baseline and after 1,3,6 and 12 months. Results: The study showed that the PRP group have significant reduction in VAS scores at 1 (p= 0.003), 3 (p= 0.0001), 6 (p= 0.0001) and 12 (p= 0.000) months when compared to HA. In addition, the PRP group illustrated greater improvement in WOMAC physical activity scale at 12 months (p= 0.008) when compared to the HA group. Combining HA and PRP resulted in a significant decreases in pain (p=0.0001) and functional limitation (p=0.0001) when compared to HA alone at 1 year post treatment; and significantly increased physical function at 1 (p=0.0004) and 3 (p=.011) months when compared to PRP alone. Conclusion: The findings of the study support the use of autologous PRP as an effective treatment of mild to moderate knee osteoarthritis. It also shows that the combination of HA and PRP resulted to better outcomes than HA alone up to 1 year and

  15. Posterior femoral condylar offset after total knee replacement in the risk of knee flexion contracture.

    PubMed

    Onodera, Tomohiro; Majima, Tokifumi; Nishiike, Osamu; Kasahara, Yasuhiko; Takahashi, Daisuke

    2013-08-01

    The aim of this study was to clarify the risk of knee flexion contracture associated with a posterior femoral condylar offset after total knee replacement (TKR). Radiographs from 100 healthy Japanese volunteers were included in the study. We evaluated femoral component posterior offset in various implants and compared them with the normal Japanese knee. Posterior offset of the femoral condyle is up to a maximum of 4.7 times greater than that of the healthy Japanese knee in all knee implants. Excess posterior offset of the femoral condyle in TKR prostheses may cause knee joint flexion contracture due to the relative shortening of the posterior soft tissue.

  16. Immediate effect of Masai Barefoot Technology shoes on knee joint moments in women with knee osteoarthritis.

    PubMed

    Tateuchi, Hiroshige; Taniguchi, Masashi; Takagi, Yui; Goto, Yusuke; Otsuka, Naoki; Koyama, Yumiko; Kobayashi, Masashi; Ichihashi, Noriaki

    2014-01-01

    Footwear modification can beneficially alter knee loading in patients with knee osteoarthritis. This study evaluated the effect of Masai Barefoot Technology shoes on reductions in external knee moments in patients with knee osteoarthritis. Three-dimensional motion analysis was used to examine the effect of Masai Barefoot Technology versus control shoes on the knee adduction and flexion moments in 17 women (mean age, 63.6 years) with radiographically confirmed knee osteoarthritis. The lateral and anterior trunk lean values, knee flexion and adduction angles, and ground reaction force were also evaluated. The influence of the original walking pattern on the changes in knee moments with Masai Barefoot Technology shoes was evaluated. The knee flexion moment in early stance was significantly reduced while walking with the Masai Barefoot Technology shoes (0.25±0.14Nm/kgm) as compared with walking with control shoes (0.30±0.19 Nm/kgm); whereas the knee adduction moment showed no changes. Masai Barefoot Technology shoes did not increase compensatory lateral and anterior trunk lean. The degree of knee flexion moment in the original walking pattern with control shoes was correlated directly with its reduction when wearing Masai Barefoot Technology shoes by multiple linear regression analysis (adjusted R2=0.44, P<0.01). Masai Barefoot Technology shoes reduced the knee flexion moment during walking without increasing the compensatory trunk lean and may therefore reduce external knee loading in women with knee osteoarthritis.

  17. The effect of orthotic devices on knee adduction moment, pain and function in medial compartment knee osteoarthritis: a literature review.

    PubMed

    Baghaei Roodsari, Roshanak; Esteki, Ali; Aminian, Gholamreza; Ebrahimi, Ismaeil; Mousavi, Mohammad Ebramim; Majdoleslami, Basir; Bahramian, Fatemeh

    2016-03-15

    Background Knee braces and foot orthoses are commonly used to improve knee adduction moment, pain and function in subjects with knee osteoarthritis (OA). However, no literature review has been performed to compare the effects of foot orthoses and knee braces in this group of patients. Purpose The aim of this review was to evaluate the effects of foot orthoses and knee braces on knee adduction moment, pain and function in individuals with knee OA. Study design Literature review. Method The search strategy was based on the Population Intervention Comparison Outcome method. A search was performed in PubMed, Science Direct, Google Scholar and ISI web of knowledge databases using the PRISMA method and based on selected keywords. Thirty-one related articles were selected for final evaluation. Results The results of the analysis of these studies demonstrated that orthotic devices reduce knee adduction moment and also improve pain and function in individuals with knee OA. Conclusion Foot orthoses may be more effective in improving pain and function in subjects with knee OA. Both knee braces and foot orthoses reduce the knee adduction moment in knee OA and consequently patients typically do not need to use knee braces for a long period of time. Also, foot orthoses and knee braces may be more effective for medial compartment knee OA patients due to the fact that this treatment helps improve pain and function. Implications for Rehabilitation Knee braces and foot orthoses are commonly used for improving knee adduction moment, pain and function in subjects with knee osteoarthritis (OA). Orthotic devices can reduce knee adduction moment, pain and improve function in knee OA. The combined use of a knee braces and foot orthoses can provide more improvement in knee adduction moment, reduced pain and increased function.

  18. Comparison of knee gait kinematics of workers exposed to knee straining posture to those of non-knee straining workers.

    PubMed

    Gaudreault, Nathaly; Hagemeister, Nicola; Poitras, Stéphane; de Guise, Jacques A

    2013-06-01

    Workers exposed to knee straining postures, such as kneeling and squatting, may present modifications in knee gait kinematics that can make them vulnerable to osteoarthritis. In this study, knee kinematics of workers exposed to occupational knee straining postures (KS workers) were compared to those of non-knee straining (non-KS) workers. Eighteen KS workers and 20 non-KS workers participated in the study. Three-dimensional gait kinematic data were recorded at the knee using an electromagnetic motion tracking system. The following parameters were extracted from flexion/extension, adduction/abduction and internal/external rotation angle data and used for group comparisons: knee angle at initial foot contact, peak angles, minimal angles and angle range during the entire gait cycle. Group comparisons were performed with Student t-tests. In the sagittal plane, KS workers had a greater knee flexion angle at initial foot contact, a lower peak knee flexion angle during the swing phase and a lower angle range than non-KS workers (p<0.05). In the frontal plane, all parameters indicated that KS workers had their knees more adducted than non-KS workers. External/internal rotation range was greater for KS workers. This study provides new knowledge on work related to KS postures and knee kinematics. The results support the concept that KS workers might exhibit knee kinematics that are different from those of non-KS workers.

  19. An Open Randomized Trial Comparing the Effects of Oral NSAIDs Versus Steroid Intra-Articular Infiltration in Congestive Osteoarthritis of the Knee

    PubMed Central

    Dieu-Donné, Ouédraogo; Théodore, Ouédraogo; Joëlle, Zabsonré/Tiendrébéogo; Pierre, Dionou; Smaïla, Ouédraogo; Christian, Compaoré; Fulgence, Kaboré; Joseph, Drabo Youssouf

    2016-01-01

    Objective: To compare the efficacy on pain and joint function of NSAIDs versus steroid intra-articular infiltration in congestive knee osteoarthritis. Patients and Methods: Open randomized study comparing a series of patients treated with NSAIDs for 21 days and another who received steroid intra-articular infiltration (SIAI) spaced at every 7 days. The visual analog scale was used for the weekly assessment of spontaneous pain and pain when walking. Lequesne functional pain scale was used to assess the functional impact of knee osteoarthritis. Results: Seventy patients were enrolled, including 35 in the NSAID arm and 35 in SIAI arm. Forty-nine (70%) had stage III of Kellgren and Lawrance scale. On admission, the average pain intensity was 50.46 ± 30.93 in the NSAID arm and 60.92 ± 30 in SIAI arm (p = 0.0189). At the end of follow-up, pain intensity was 6.72 ± 13 in NSAIDs patients and 17.80 ± 21 in SIAI one (p = 0.001). The average intensity of pain on walking was 64.41 ± 22.61. It was 53.33 ± 22.31 in NSAID’s against 74.85 ± 17.55 in SIAI patients (P <0.0001). At the end of the treatment, they were respectively 19.11 ± 11.37, and 35 ± 30.69 (P = 0.0085). Conclusion: Corticosteroid injections have a short efficacy compared to NSAIDs. Prescribing NSAIDs should consider the cons-indications, comorbidities and their deleterious digestive, renal, and cardiovascular effect. PMID:27006727

  20. Cementless total knee arthroplasty

    PubMed Central

    Risitano, Salvatore; Sabatini, Luigi; Giachino, Matteo; Agati, Gabriele; Massè, Alessandro

    2016-01-01

    Interest for uncemented total knee arthroplasty (TKA) has greatly increased in recent years. This technique, less used than cemented knee replacement in the last decades, sees a revival thanks an advance in prosthetic design, instrumentation and operative technique. The related literature in some cases shows conflicting data on survival and on the revision’s rate, but in most cases a success rate comparable to cemented TKA is reported. The optimal fixation in TKA is a subject of debate with the majority of surgeons favouring cemented fixation. PMID:27162779

  1. Comparative effects of a new calcium channel antagonist, mepirodipine, on rabbit spontaneously beating sino-atrial node cells.

    PubMed

    Satoh, H; Hashimoto, K

    1991-01-25

    The effects of mepirodipine, a new 1,4-dihydropyridine calcium antagonist, on the membrane potentials were examined on spontaneously beating rabbit sino-atrial (SA) node cells and on the membrane currents under voltage-clamped conditions. Mepirodipine 3 x 10(-9) M significantly decreased the action potential amplitude and the maximum rate of depolarization. The action potential duration and the cycle length were prolonged. Sinus arrest occurred at 10(-8) M in all of five preparations. In voltage-clamped SA node cells, mepirodipine in concentrations higher than 3 x 10(-9) M decreased the slow inward current. It did not affect the steady state outward current and the hyperpolarization-activated inward current. Verapamil, diltiazem and nifedipine produced similar changes in the action potential parameters, but at a concentration of 10(-6) M. At concentrations higher than 10(-5) M, they elicited sinus arrest. These results suggest that mepirodipine is a more potent inhibitor of spontaneous calcium-dependent SA node impulse generation than the three other calcium antagonists tested.

  2. Comparative studies on mitochondria isolated from neuron-enriched and glia-enriched fractions of rabbit and beef brain.

    PubMed

    Hamberger, A; Blomstrand, C; Lehninger, A L

    1970-05-01

    Fractions enriched in neuronal and glial cells were obtained from dispersions of whole beef brain and rabbit cerebral cortex by large-scale density gradient centrifugation procedures. The fractions were characterized by appropriate microscopic observation. Mitochondria were then isolated from these fractions by differential centrifugation of their homogenates. The two different types of mitochondria were characterized with respect to certain enzyme activities, respiratory rate, rate of protein synthesis, and their buoyant density in sucrose gradients. The mitochondria from the neuron-enriched fraction were distinguished by a higher rate of incorporation of amino acids into protein, higher cytochrome oxidase activity, and a higher buoyant density in sucrose density gradients. Mitochondria from the glia-enriched fraction showed relatively high monoamine oxidase and Na(+)- and K(+)-stimulated ATPase activities. The rates of oxidation of various substrates and the acceptor control ratios did not differ appreciably between the two types of mitochondria. The difference in the buoyant density of mitochondria isolated from the neuron-enriched and glia-enriched cell fractions was utilized in attempts to separate neuronal and glial mitochondria from the mixed mitochondria obtained from whole brain homogenates in shallow sucrose gradients. The appearance of two peaks of cytochrome oxidase, monoamine oxidase, and protein concentration in such gradients shows the potential feasibility of such an approach.

  3. Gait Analysis of Conventional Total Knee Arthroplasty and Bicruciate Stabilized Total Knee Arthroplasty Using a Triaxial Accelerometer

    PubMed Central

    Saito, Hidetomo; Aizawa, Toshiaki; Miyakoshi, Naohisa; Shimada, Yoichi

    2016-01-01

    One component of conventional total knee arthroplasty is removal of the anterior cruciate ligament, and the knee after total knee arthroplasty has been said to be a knee with anterior cruciate ligament dysfunction. Bicruciate stabilized total knee arthroplasty is believed to reproduce anterior cruciate ligament function in the implant and provide anterior stability. Conventional total knee arthroplasty was performed on the right knee and bicruciate stabilized total knee arthroplasty was performed on the left knee in the same patient, and a triaxial accelerometer was fitted to both knees after surgery. Gait analysis was then performed and is reported here. The subject was a 78-year-old woman who underwent conventional total knee arthroplasty on her right knee and bicruciate stabilized total knee arthroplasty on her left knee. On the femoral side with bicruciate stabilized total knee arthroplasty, compared to conventional total knee arthroplasty, there was little acceleration in the x-axis direction (anteroposterior direction) in the early swing phase. Bicruciate stabilized total knee arthroplasty may be able to replace anterior cruciate ligament function due to the structure of the implant and proper anteroposterior positioning. PMID:27648328

  4. [Arthro-scanner of the knee: current indication, examination of the femoro-tibial compartment. Comparative study with classical simple-contrast media arthrography].

    PubMed

    Pelousse, F; Olette, J

    1993-12-01

    The authors report on a series of 50 single contrast knee arthroscans and describe a method of examination in fine sections that allows for a detailed analysis of the femoro-tibial compartment. The authors compared the sensitivity of the single contrast arthrography with their arthroscanner technique. Thus they prove the major interest of the fine section arthroscanner in assessing chondropathies of all types, the frequency and stage of which are heavily underestimated in conventional arthrography, not only in respect of the patella but also where the other covering cartilages are concerned. They also demonstrate the additional interest of the arthroscanner for certain meniscus and ligament lesions as well as for detecting osteochondromatosis nodules.

  5. Long-term clinical outcomes and survivorship after total knee arthroplasty using a rotating platform knee prosthesis: a meta-analysis.

    PubMed

    Hopley, Colin D J; Crossett, Lawrence S; Chen, Antonia F

    2013-01-01

    A systematic search identified 29 papers reporting survivorship and clinical and function Knee Society Scores (KSS) of 6437 total knee replacements using the Low Contact Stress (LCS) Rotating Platform (RP) mobile bearing knee. Low Contact Stress RP survivorship and KSS outcomes were compared with non-LCS knees in the Swedish knee registry at comparable time periods and in 2 independent systematic reviews of knee arthroplasty outcomes. There is a substantial body of mainly observational evidence supporting the LCS RP knee. Knee Society Score outcomes were comparable for LCS RP and non-LCS RP knees at up to 15 years of follow-up, with mean clinical and function scores ranging from 72 to 96 and 58 to 90, respectively. Survivorship of LCS RP knees up to 14 years was higher than that for all knees in the Swedish Knee Registry.

  6. Comparative study of NMP-preloaded and dip-loaded membranes for guided bone regeneration of rabbit cranial defects.

    PubMed

    Karfeld-Sulzer, Lindsay S; Ghayor, Chafik; Siegenthaler, Barbara; Gjoksi, Bebeka; Pohjonen, Timo H; Weber, Franz E

    2017-02-01

    Guided bone regeneration (GBR) has been utilized for several decades for the healing of cranio-maxillofacial bone defects and, particularly in the dental field, by creating space with a barrier membrane to exclude soft tissue and encourage bone growth in the membrane-protected volume. Although the first membranes were non-resorbable, a new generation of GBR membranes aims to biodegrade and provide bioactivity for better overall results. The Inion GTR™ poly(lactide-co-glycolide) (PLGA) membrane is not only resorbable but also bioactive, since it includes N-methylpyrrolidone (NMP), which has been shown to promote bone regeneration. In this study, the effects of loading different amounts of NMP onto the membrane through chemical vapour deposition or dipping have been explored. In vitro release demonstrated that lower levels of NMP led to lower NMP concentrations and slower release, based on total NMP loaded in the membrane. The dipped membrane released almost all of the NMP within 15 min, leading to a high NMP concentration. For the in vivo studies in rabbits, 6 mm calvarial defects were created and left untreated or covered with an ePTFE membrane or PLGA membranes dipped in, or preloaded with, NMP. Evaluation of the bony regeneration revealed that the barrier membranes improved bony healing and that a decrease in NMP content improved the performance. Overall, we have demonstrated the potential of these PLGA membranes with a more favourable NMP release profile and the significance of exploring the effect of NMP on these PLGA membranes with regard to bone ingrowth. Copyright © 2014 John Wiley & Sons, Ltd.

  7. Treatment of antigen-induced arthritis in rabbits with dysprosium-165-ferric hydroxide macroaggregates

    SciTech Connect

    Zuckerman, J.D.; Sledge, C.B.; Shortkroff, S.; Venkatesan, P.

    1989-01-01

    Dysprosium-165-ferric hydroxide macroaggregates (/sup 165/Dy-FHMA) was used as an agent of radiation synovectomy in an antigen-induced arthritis model in New Zealand white rabbits. Animals were killed up to 6 months after treatment. /sup 165/Dy-FHMA was found to have a potent but temporary antiinflammatory effect on synovium for up to 3 months after treatment. Treated knees also showed significant preservation of articular cartilage architecture and proteoglycan content compared with untreated controls, but only during the first 3 months after treatment. In animals killed 3 and 6 months after treatment there were only minimal differences between the treated and untreated knees, indicating that the antiinflammatory effects on synovial tissue and articular cartilage preservation were not sustained.

  8. Knee Menisci.

    PubMed

    Bryceland, James Kevin; Powell, Andrew John; Nunn, Thomas

    2017-04-01

    The menisci of the knees are semicircular fibrocartilaginous structures consisting of a hydrophilic extracellular matrix containing a network of collagen fibers, glycoproteins, and proteoglycans maintained by a cellular component. The menisci are responsible for more than 50% of load transmission across the knee and increase joint congruity thereby also aiding in fluid film lubrication of the joint. In the United Kingdom, meniscal tears are the most common form of intra-articular knee injury and one of the commonest indications for orthopedic intervention. The management of these injuries is dependent on the location within the meniscus (relative to peripheral blood supply) and the pattern of tear. Removal of meniscus is known to place the knee at increased risk of osteoarthritis; therefore repair of meniscal tears is preferable. However, a significant proportion of tears are irreparable and can only be treated by partial or even complete meniscectomy. More recent studies have shown encouraging results with meniscal replacement in this situation, though further work is required in this area.

  9. Knee CT scan

    MedlinePlus

    CAT scan - knee; Computed axial tomography scan - knee; Computed tomography scan - knee ... scanners can perform the exam without stopping.) A computer makes several images of the body area. These ...

  10. Knee pain (image)

    MedlinePlus

    ... front of the knee can be due to bursitis, arthritis, or softening of the patella cartilage as ... knee. Overall knee pain can be due to bursitis, arthritis, tears in the ligaments, osteoarthritis of the ...

  11. Total Knee Replacement

    MedlinePlus

    ... stability. The long thigh muscles give the knee strength. All remaining surfaces of the knee are covered ... physical examination. This will assess knee motion, stability, strength, and overall leg alignment. • X-rays. These images ...

  12. Knee joint replacement

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/002974.htm Knee joint replacement To use the sharing features on this page, please enable JavaScript. Knee joint replacement is a surgery to replace a knee ...

  13. Water on the Knee

    MedlinePlus

    ... your knee joint. Some people call this condition "water on the knee." A swollen knee may be ... Choose low-impact exercise. Certain activities, such as water aerobics and swimming, don't place continuous weight- ...

  14. BIORESORBABLE POLYMERIC MENISCAL PROSTHESIS: STUDY IN RABBITS

    PubMed Central

    Cardoso, Tulio Pereira; de Rezende Duek, Eliana Aparecida; Amatuzzi, Marco Martins; Caetano, Edie Benedito

    2015-01-01

    Objective: To induce growth of a neomeniscus into the pores of a prosthesis in order to protect the knee joint cartilage. Methods: 70 knees of 35 New Zealand rabbits were operated. The rabbits were five to seven months old, weighed 2 to 3.8 kilograms, and 22 were male and 13 were female. Each animal underwent medial meniscectomy in both knees during a single operation. A bioabsorbable polymeric meniscal prosthesis composed of 70% polydioxanone and 30% L-lactic acid polymer was implanted in one side. The animals were sacrificed after different postoperative time intervals. The femoral condyles and neomeniscus were subjected to histological analysis. Histograms were used to measure the degradation and absorption of the prosthesis, the growth of meniscal tissue in the prosthesis and the degree of degradation of the femoral condyle joint cartilage. Results: The data obtained showed that tissue growth histologically resembling a normal meniscus occurred, with gradual absorption of the prosthesis, and the percentages of chondrocytes on the control side and prosthesis side. Conclusion: Tissue growth into the prosthesis pores that histologically resembled the normal rabbit meniscus was observed. The joint cartilage of the femoral condyles on the prosthesis side presented greater numbers of chondrocytes in all its layers. PMID:27022549

  15. Evaluation of the effect of Elaeagnus angustifolia alone and combined with Boswellia thurifera compared with ibuprofen in patients with knee osteoarthritis: a randomized double-blind controlled clinical trial.

    PubMed

    Karimifar, Mansoor; Soltani, Rasool; Hajhashemi, Valiollah; Sarrafchi, Sara

    2017-03-27

    Osteoarthritis (OA) is one of the most common articular disorders. Many patients do not respond to acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs), the mainstay of pharmacotherapy for knee OA. The plants Elaeagnus angustifolia and Boswellia thurifera have anti-inflammatory and analgesic properties. This study aimed to evaluate the effect of E. angustifolia alone and in combination with B. thurifera compared with ibuprofen in patients with knee osteoarthritis. In a randomized double-blind controlled clinical trial, 75 patients with knee OA were randomly and equally assigned to one of three groups Elaeagnus (n = 23), Elaeagnus/Boswellia (n = 26), and ibuprofen (n = 26) to receive the capsules of Elaeagnus, Elaeagnus/Boswellia, and ibuprofen, respectively, three times daily with meals for 4 weeks. Pain severity based on VAS (visual analog scale, 0 to 10 scale) and the scores of LPFI (Lequesne Pain and Function Index) and PGA (patient global assessment) were determined pre- and post-intervention for all patients. All interventions had significant lowering effects on VAS, LPFI, and PGA scores (P < 0.001 for all parameters) with no significant difference between groups in terms of effects on all evaluated parameters. Consumption of E. angustifolia fruit extract either alone or in combination with Boswellia oleo-gum resin extract could decrease pain and improve function in patients with knee osteoarthritis comparable to ibuprofen.

  16. Telerehabilitation after total knee replacement in Italy: cost-effectiveness and cost-utility analysis of a mixed telerehabilitation-standard rehabilitation programme compared with usual care

    PubMed Central

    Fusco, Francesco; Turchetti, Giuseppe

    2016-01-01

    Objectives To assess cost-effectiveness and cost utility of telerehabilitation (TR) versus standard rehabilitation (SR) after total knee replacement (TKR). Design Markov decision modelling of cost-effectiveness and cost-utility analysis based on patient-level and secondary data sources employing Italian National Health Service (NHS; Ita-NHS) and Society perspectives. Setting Primary care units (PCUs) in Italy. Participants Patients discharged after TKR. Interventions Mixed SR-TR service (10 face-to-face sessions and 10 telesessions) versus SR (20 face-to-face sessions) Primary and secondary outcome measures The incremental cost per additional knee flexion range of motion (ROM) and per QALY gained by SR-TR compared with SR. Second, we considered the probability of being cost-effective and the probability of being more effective and less expensive. Results TR appears to be the cost-effective in the base case and in all of the considered scenarios, but is no longer more effective and less expensive if transportation costs are excluded. Comparing SR-TR with SR, the incremental cost-effectiveness ratio (ICER) adopting the Ita-NHS perspective for the base case was −€117/ROM gained. The cost-effectiveness probability for SR-TR was 0.98 (ceiling ratio: €50/ROM), while the joint probability of being more effective and less expensive was 0.87. Assuming that TR would increase health-related quality of life (HRQOL) utilities by 2.5%, the ICER adopting Ita-NHS perspective is −€960/QALY (cost-effectiveness probability: 1; ceiling ratio: €30 000/QALY). All the performed sensitivity analyses did not change the conclusions, but if transportation costs were excluded, the probability for SR-TR of being more clinically effective and less expensive reduced to 0.56. Conclusions The analysis suggested SR-TR to be cost-effective, even less expensive and more effective if the PCUs provide ambulance transportations. However, the uncertainty related to TR costs, HRQOL and long

  17. Use of technetium-99m methylene diphosphonate and gallium-67 citrate scans after intraarticular injection of Staphylococcus aureus into knee joints of rabbits with chronic antigen-induced arthritis

    SciTech Connect

    Mahowald, M.L.; Raskind, J.R.; Peterson, L.; Gerding, D.; Raddatz, D.A.; Shafer, R.

    1986-08-01

    Numerous clinical studies have questioned the ability of radionuclide scans to differentiate septic from aseptic joint inflammation. A clinical study may not be able to document an underlying disease process or duration of infection and, thus, may make conclusions about the accuracy of scan interpretations open to debate. In this study, the Dumonde-Glynn model of antigen-induced arthritis in rabbits was used as the experimental model to study technetium and gallium scans in Staphylococcus aureus infection of arthritic and normal joints. Gallium scans were negative in normal rabbits, usually negative in antigen-induced arthritis, but positive in septic arthritis. The bone scan was usually negative in early infection but positive in late septic arthritis, a finding reflecting greater penetration of bacteria into subchondral bone because of the underlying inflammatory process.

  18. Associations of knee muscle force, bone malalignment, and knee-joint laxity with osteoarthritis in elderly people

    PubMed Central

    Nakagawa, Kazumasa; Maeda, Misako

    2017-01-01

    [Purpose] From the viewpoint of prevention of knee osteoarthritis, the aim of this study was to verify how muscle strength and joint laxity are related to knee osteoarthritis. [Subjects and Methods] The study subjects consisted of 90 community-dwelling elderly people aged more than 60 years (22 males, 68 females). Femorotibial angle alignment, knee joint laxity, knee extensors and flexor muscle strengths were measured in all subjects. In addition, the subjects were divided into four groups based on the presence of laxity and knee joint deformation, and the muscle strength values were compared. [Results] There was no significant difference in knee extensor muscle strength among the four groups. However, there was significant weakness of the knee flexor muscle in the group with deformation and laxity was compared with the group without deformation and laxity. [Conclusion] Decreased knee flexor muscle strengths may be involved in knee joint deformation. The importance of muscle strength balance was also considered. PMID:28356631

  19. Associations of knee muscle force, bone malalignment, and knee-joint laxity with osteoarthritis in elderly people.

    PubMed

    Nakagawa, Kazumasa; Maeda, Misako

    2017-03-01

    [Purpose] From the viewpoint of prevention of knee osteoarthritis, the aim of this study was to verify how muscle strength and joint laxity are related to knee osteoarthritis. [Subjects and Methods] The study subjects consisted of 90 community-dwelling elderly people aged more than 60 years (22 males, 68 females). Femorotibial angle alignment, knee joint laxity, knee extensors and flexor muscle strengths were measured in all subjects. In addition, the subjects were divided into four groups based on the presence of laxity and knee joint deformation, and the muscle strength values were compared. [Results] There was no significant difference in knee extensor muscle strength among the four groups. However, there was significant weakness of the knee flexor muscle in the group with deformation and laxity was compared with the group without deformation and laxity. [Conclusion] Decreased knee flexor muscle strengths may be involved in knee joint deformation. The importance of muscle strength balance was also considered.

  20. Rabbit hematology.

    PubMed

    Marshall, Kemba L

    2008-09-01

    Using laboratory animal medicine as an established resource, companion animal veterinarians have access to many physiologic and basic science studies that we can now merge with our clinical impressions. By working with reference laboratories, companion animal veterinarians are poised to accelerate our knowledge of the normal rabbit rapidly. The aim of this article is to discuss normal hematopoiesis and infectious and metabolic diseases that specifically target the hemolymphatic system. Additionally, photographic representation of cell types is provided.

  1. An in vivo rabbit model for the evaluation of antimicrobial peripherally inserted central catheter to reduce microbial migration and colonization as compared to an uncoated PICC.

    PubMed

    Allan, Nicholas D; Giare-Patel, Kamna; Olson, Merle E

    2012-01-01

    Infection is the leading complication associated with intravascular devices, and these infections develop when a catheter becomes colonized by microorganisms. To combat this issue, medical device manufacturers seek to provide healthcare facilities with antimicrobial medical devices to prevent or reduce the colonization. In order to adequately evaluate these devices, an in vivo model is required to accurately assess the performance of the antimicrobial devices in a clinical setting. The model presented herein was designed to provide a simulation of the subcutaneous tunnel environment to evaluate the ability of an antimicrobial peripherally inserted central catheter (PICC), coated with chlorhexidine based technology, to reduce microbial migration and colonization compared to an uncoated PICC. Three samples of control, uncoated PICCs and three samples of coated PICCs were surgically tunneled into the backs of female New Zealand White rabbits. The insertion sites were then challenged with Staphylococcus aureus at the time of implantation. Animals were evaluated out to thirty days and sacrificed. Complete en bloc dissection and evaluation of the catheter and surrounding tissue demonstrated that the chlorhexidine coated catheter was able to significantly reduce microbial colonization and prevent microbial migration as compared to the standard, un-treated catheter.

  2. Interaction of bovine (BSA), rabbit (RSA), and porcine (PSA) serum albumins with cationic single-chain/gemini surfactants: a comparative study.

    PubMed

    Gull, Nuzhat; Sen, Priyankar; Khan, Rizwan Hasan; Kabir-ud-Din

    2009-10-06

    The interactions among bovine, rabbit, and porcine serum albumins and single-chain cationic surfactant cetyltrimethylammonium bromide (CTAB) versus its gemini counterpart (designated as G4) have been studied. The studies were carried out in an aqueous medium at pH 7.0 using UV, intrinsic and extrinsic fluorescence spectroscopy, and far-UV circular dichroism techniques. The results indicate that compared to CTAB, G4 interacts strongly with the serum albumins, resulting in a significantly larger unfolding or decrease in alpha-helical content as reflected by the significantly larger decrease in ellipticity in the far-UV range. Unlike CTAB, a remarkable increase in the alpha-helical content of BSA at 625 microM G4 and at 250 microM G4 for RSA and PSA is observed. The appearance of conformational changes and saturation points in the proteins occurs at considerably lower [G4] compared to [CTAB]. The results obtained from the multi-technique approach are ascribed to the stronger forces in G4 owing to the presence of two charged headgroups and two hydrocarbon tails. Keeping the results in view, it is suggested that the gemini surfactants may be effectively used in the renaturation of proteins produced in genetically engineered cells via the artificial chaperone protocol and may also prove useful in drug delivery as solubilizing agents to recover proteins from insoluble inclusion bodies.

  3. Arthroplasty of a Charcot knee

    PubMed Central

    Babazadeh, Sina; Stoney, James D.; Lim, Keith; Choong, Peter F.M.

    2010-01-01

    The Charcot knee - or neuropathic arthropathy - presents a considerable challenge to the orthopaedic surgeon. Caused by a combination of sensory, motor and autonomic neuropathy, it was originally described as an arthritic sequelae of neurosyphilis. In today's western orthopaedics it is more often caused by diabetes. A Charcot knee is often symptomatically painful and unstable. Traditional management has usually been conservative or arthrodesis, with limited success. Arthroplasty of a Charcot joint has commonly been avoided at all costs. However, in the right patient, using the right technique, arthroplasty can significantly improve the symptoms of a Charcot joint. This article explores the evidence surrounding the role of arthroplasty in the management of a Charcot knee. Arthroplasty is compared to other forms of treatment and specific patient demographics and surgical techniques are explored in an attempt to define the role of arthroplasty in the management of a Charcot knee. PMID:21808708

  4. Articular cartilage grading of the knee: diagnostic performance of fat-suppressed 3D volume isotropic turbo spin-echo acquisition (VISTA) compared with 3D T1 high-resolution isovolumetric examination (THRIVE).

    PubMed

    Lee, Young Han; Hahn, Seok; Lim, Daekeon; Suh, Jin-Suck

    2017-02-01

    Background Conventionally, two-dimensional (2D) fast spin-echo (FSE) sequences have been widely used for clinical cartilage imaging as well as gradient (GRE) sequences. Recently, three-dimensional (3D) volumetric magnetic resonance imaging (MRI) has been introduced with one 3D volumetric scan, and this is replacing slice-by-slice 2D MR scans. Purpose To evaluate the image quality and diagnostic performance of two 3D sequences for abnormalities of knee cartilage: fat-suppressed (FS) FSE-based 3D volume isotropic turbo spin-echo acquisition (VISTA) and GRE-based 3D T1 high-resolution isovolumetric examination (THRIVE). Material and Methods The institutional review board approved the protocol of this retrospective review. This study enrolled 40 patients (41 knees) with arthroscopically confirmed abnormalities of cartilage. All patients underwent isovoxel 3D-VISTA and 3D-THRIVE MR sequences on 3T MRI. We assessed the cartilage grade on the two 3D sequences using arthroscopy as a gold standard. Inter-observer agreement for each technique was evaluated with the intraclass correlation coefficient (ICC). Differences in the area under the curve (AUC) were compared between the 3D-THRIVE and 3D-VISTA. Results Although inter-observer agreement for both sequences was excellent, the inter-observer agreement for 3D-VISTA was higher than for 3D-THRIVE for cartilage grading in all regions of the knee. There was no significant difference in the diagnostic performance ( P > 0.05) between the two sequences for detecting cartilage grade. Conclusion FSE-based 3D-VISTA images had good diagnostic performance that was comparable to GRE-based 3D-THRIVE images in the evaluation of knee cartilage, and can be used in routine knee MR protocols for the evaluation of cartilage.

  5. Comparative study of conventional hip-knee-ankle-foot orthoses versus reciprocating-gait orthoses for children with high-level paraparesis.

    PubMed

    Katz, D E; Haideri, N; Song, K; Wyrick, P

    1997-01-01

    We evaluated eight children with thoracic or high lumbar-level paraparesis for metabolic performance while ambulating with custom fabricated thermoplastic hip-knee-ankle-foot orthoses (HKAFOs) and reciprocating-gait orthoses (RGOs). Seven of the eight children had myelomeningocele. Each patient was tested in both systems at self-selected speeds in a crossover study design. At self-selected speeds, the level of exercise intensity for both thoracic and high-lumbar patients with either orthosis was lower than that for normal children. The average metabolic cost of walking in the RGO was twice that of normal children, as compared with six times normal in HKAFOs. For the four thoracic-level patients, there was a significantly higher oxygen cost of ambulation in using HKAFOs versus RGOs. No significant difference in metabolic performance was found for the high-lumbar patients. Velocity of ambulation was faster in the RGOs than in the HKAFOs. For thoracic-level patients, our data suggest that an RGO will provide a faster, more energy-efficient gait than a statically locked HKAFO. For high-lumbar patients, no significant difference was found between the two orthoses. Seven of eight children preferred the RGO over the HKAFO.

  6. A Randomized Controlled Study to Compare the Total and Hidden Blood Loss in Computer-Assisted Surgery and Conventional Surgical Technique of Total Knee Replacement

    PubMed Central

    Singla, Amit; Kumar, Vijay; Lekha, Chandra; Karthikeyan, G.; Malik, Vishwas

    2015-01-01

    Background Total knee arthroplasty (TKA) is associated with considerable blood loss. Computer-assisted surgery (CAS) is different from conventional TKA as it avoids opening the intramedullary canal. Hence, CAS should be associated with less blood loss. Methods Fifty-seven patients were randomized into two groups of CAS and conventional TKA. In conventional group intramedullary femoral and extramedullary tibial jigs were used whereas in CAS group imageless navigation system was used. All surgeries were done under tourniquet. Total and hidden blood loss was calculated in both groups and compared. Results The mean total blood loss was 980 mL in conventional group and 970 mL in CAS group with median of 1,067 mL (range, 59 to 1,791 mL) in conventional group and 863 mL (range, 111 to 2,032 mL) in CAS group. There was no significant difference in total blood loss between the two groups (p = 0.811). We have found significant hidden blood loss in both techniques, which is 54.8% of the total loss in the conventional technique and 59.5% in the computer-assisted navigation technique. Conclusions There is no significant difference in total and hidden blood loss in the TKA in CAS and conventional TKA. However, there is significant hidden blood loss in both techniques. There was no relation of tourniquet time with blood loss. PMID:26217468

  7. Immediate Effects of an Elastic Knee Sleeve on Frontal Plane Gait Biomechanics in Knee Osteoarthritis

    PubMed Central

    Schween, Raphael; Gehring, Dominic; Gollhofer, Albert

    2015-01-01

    Introduction Osteoarthritis of the knee affects millions of people. Elastic knee sleeves aim at relieving symptoms. While symptomatic improvements have been demonstrated as a consequence of elastic knee sleeves, evidence for biomechanical alterations only exists for the sagittal plane. We therefore asked what effect an elastic knee sleeve would have on frontal plane gait biomechanics. Methods 18 subjects (8 women, 10 men) with osteoarthritis of the medial tibiofemoral joint walked over ground with and without an elastic knee sleeve. Kinematics and forces were recorded and joint moments were calculated using an inverse dynamics approach. Conditions with sleeve and without sleeve were compared with paired t-Tests. Results With the sleeve, knee adduction angle at ground contact was reduced by 1.9±2.1° (P = 0.006). Peak knee adduction was reduced by 1.5±1.6° (P = 0.004). The first peak knee adduction moment and positive knee adduction impulse were decreased by 10.1% (0.74±0.9 Nm•kg-1; P = 0.002) and 12.9% (0.28±0.3 Nm•s•kg-1; P < 0.004), respectively. Conclusion Our study provides evidence that wearing an elastic knee sleeve during walking can reduce knee adduction angles, moments and impulse in subjects with knee osteoarthritis. As a higher knee adduction moment has previously been identified as a risk factor for disease progression in patients with medial knee osteoarthritis, we speculate that wearing a knee sleeve may be beneficial for this specific subgroup. PMID:25621488

  8. Experimental infection of the rabbit tick, Haemaphysalis leporispalustris, with the bacterium Rickettsia rickettsii, and comparative biology of infected and uninfected tick lineages.

    PubMed

    Freitas, Luciana Helena T; Faccini, João Luiz H; Labruna, Marcelo B

    2009-04-01

    The present study consisted of two experiments that evaluated experimental infections of Haemaphysalis leporispalustris ticks by a Brazilian strain of Rickettsia rickettsii, and their effect on tick biology. In experiment I, ticks were exposed to R. rickettsii during the larval, nymphal or adult stages by feeding on rabbits (Oryctolagus cuniculus) needle-inoculated with R. rickettsii, and thereafter reared on uninfected rabbits for the entire next tick generation. Regardless of the tick stage that acquired the infection, all subsequent tick stages were shown to be infected by PCR (infection rates varying from 1.3 to 41.7%), and were able to transmit R. rickettsii to uninfected rabbits, as demonstrated by rabbit seroconversion, guinea pig inoculation with rabbit blood, and PCR on rabbit blood. In Experiment II, ticks were exposed to R. rickettsii during the larval stage by feeding on rabbits co-infested with R. rickettsii-infected adult ticks, and thereafter reared on uninfected rabbits until the next generation of larvae. Again, all subsequent tick stages were shown to be infected by PCR (infection rates varying from 3.0 to 40.0%), and were able to transmit R. rickettsii to uninfected rabbits. Thus, it was demonstrated that larvae, nymphs, and adults of H. leporispalustris were able to acquire and maintain the R. rickettsii infection by transstadial and transovarial transmissions within the tick population, with active transmission of the bacterium to susceptible rabbits by all parasitic stages. Analyses of biological parameters of uninfected and R. rickettsii-infected tick lineages were performed in order to evaluate possible deleterious effects of R. rickettsii to the infected tick lineages. Surprisingly, all but one of the four R. rickettsii-experimental groups of the present study showed overall better biological performance than their sibling uninfected control ticks. Results of the present study showed that H. leporispalustris could support infection by a

  9. Comparative Vaccine Efficacy of Different Isoforms of Recombinant Protective Antigen Against Bacillus anthracis Spore Challenge in Rabbits

    DTIC Science & Technology

    2006-02-06

    bovine serum, 4 mM glutamine and 00 U of Penicillin G and 100 g of streptomycin per ml D-MEM complete) supplemented with 25 mM HEPES. ne -hundred...contains small, but varying quantities of other bacterial com- ponents. A second-generation vaccine currently undergoing clinical trials is a purified...Friedlander AM. Comparative safety and efficacy against Bacillus anthracis of protective antigen and live vaccines in mice. Microb Pathog 1988;5(2):127–39

  10. In vivo knee kinematics in patients with bilateral total knee arthroplasty of 2 designs.

    PubMed

    Okamoto, Nobukazu; Breslauer, Leigh; Hedley, Anthony K; Mizuta, Hiroshi; Banks, Scott A

    2011-09-01

    Many younger and highly active patients desire to achieve high flexion after total knee arthroplasty. This study's purpose was to determine if a contemporary total knee arthroplasty design improved functional knee flexion compared with a traditional total knee arthroplasty in patients living a Western lifestyle. Ten patients with bilateral total knee arthroplasty of 2 types were studied during weight-bearing lunge, kneeling, and stair activities using fluoroscopic imaging. There were no differences in maximum knee flexion during lunging or kneeling. Statistically significant differences in tibial rotation and condylar translation were observed during the 3 activities. Although several joint kinematic differences were observed, no important functional differences were observed in clinically excellent, high performing subjects with bilateral total knee arthroplasty of 2 types.

  11. Are periprosthetic tissue reactions observed after revision of total disc replacement comparable to the reactions observed after total hip or knee revision surgery?

    PubMed Central

    Punt, Ilona M.; Austen, Shennah; Cleutjens, Jack P.M.; Kurtz, Steven M.; ten Broeke, René H.M.; van Rhijn, Lodewijk W.; Willems, Paul C.; van Ooij, André

    2011-01-01

    Study design Comparative study. Objective To compare periprosthetic tissue reactions observed after total disc replacement (TDR), total hip arthroplasty (THA) and total knee arthroplasty (TKA) revision surgery. Summary of background data Prosthetic wear debris leading to particle disease, followed by osteolysis, is often observed after THA and TKA. Although the presence of polyethylene (PE) particles and periprosthetic inflammation after TDR has been proven recently, osteolysis is rarely observed. The clinical relevance of PE wear debris in the spine remains poorly understood. Methods Number, size and shape of PE particles, as well as quantity and type of inflammatory cells in periprosthetic tissue retrieved during Charité TDR (n=22), THA (n=10) and TKA (n=4) revision surgery were compared. Tissue samples were stained with hematoxylin/eosin and examined by using light microscopy with bright field and polarized light. Results After THA, large numbers of PE particles <6 µm were observed, which were mainly phagocytosed by macrophages. The TKA group had a broad size range with many larger PE particles and more giant cells. In TDR, the size range was similar to that observed in TKA. However, the smallest particles were the most prevalent with 75% of the particles being <6 µm, as seen in revision THA. In TDR, both macrophages and giant cells were present with a higher number of macrophages. Conclusions Both small and large PE particles are present after TDR revision surgery compatible with both THA and TKA wear patterns. The similarities between periprosthetic tissue reactions in the different groups may give more insight in the clinical relevance of PE particles and inflammatory cells in the lumbar spine. The current findings may help to improve TDR design as applied from technologies previously developed in THA and TKA with the goal of a longer survival of TDR. PMID:21336235

  12. Comparative study on anesthetic potency of dental local anesthetics assessed by the jaw-opening reflex in rabbits.

    PubMed Central

    Miyoshi, T.; Aida, H.; Kaneko, Y.

    2000-01-01

    The potency of 4 local anesthetics to dental pulp was compared. Drugs were 4% articaine with 12 microgram/mL epinephrine (A12), 4% articaine with 6 microgram/mL epinephrine (A6), 2% lidocaine with 12.5 microgram/mL epinephrine (L), and 3% propitocaine with 0.03 IU/mL felypressin (P). Local anesthetics were injected into the dental root of the mandibular incisor. Electromyogram (EMG) of the digastric muscle was measured during the jaw-opening reflex induced by electrical stimulation. The disappearance of the EMG wave was judged as positive evidence of anesthesia. The determination of ED50 of the anesthetic was made by probit analysis. The ED50 of the A12 was minimal in all the tested anesthetics throughout the entire course. The potency in the A6 was 2.8 times that of the L. The potency of the A12 at the 15-minute measurement was 3.8 times that of the A6. The ED50 of the P was higher compared with those of the other 3 groups. It was concluded that articaine showed quicker onset than lidocaine and propitocaine and that there was a need to increase the dosage to attain a quick onset or to extend the duration. PMID:11881694

  13. Knee Injuries and Disorders

    MedlinePlus

    Your knee joint is made up of bone, cartilage, ligaments and fluid. Muscles and tendons help the knee joint move. When any of these structures is hurt ... your life. The most common disease affecting the knee is osteoarthritis. The cartilage in the knee gradually wears away, ...

  14. Safety and efficacy of multimodal thromboprophylaxis following total knee arthroplasty: a comparative study of preferential aspirin vs. routine coumadin chemoprophylaxis.

    PubMed

    Gesell, Mark W; González Della Valle, Alejandro; Bartolomé García, Sergio; Memtsoudis, Stavros G; Ma, Yan; Haas, Steven B; Salvati, Eduardo A

    2013-04-01

    Multimodal thromboprophylaxis encompasses preoperative VTE risk stratification, regional anesthesia, mechanical prophylaxis, and early mobilization. We determined if aspirin can be safely used for adjuvant chemoprophylaxis in patients who have a low thromboembolic risk. 1016 consecutive patients undergoing TKA received multimodal thromboprophylaxis. Aspirin was used in 67% of patients and Coumadin 33% (high risk patients, or who were on Coumadin before surgery). This study group was compared to 1001 consecutive patients who received multimodal thromboprophylaxis and routine Coumadin chemoprophylaxis. There was no significant difference in rates of VTE, PE, bleeding, complications, readmission and 90-day mortality between the two groups. There was a significantly higher rate of wound related complications in the control group (p=0.03). Multimodal thromboprophylaxis with aspirin given to the majority of patients at a low VTE risk is safe and effective in patients undergoing primary TKA.

  15. Comparative analysis of the locus control region of the rabbit beta-like gene cluster: HS3 increases transient expression of an embryonic epsilon-globin gene.

    PubMed Central

    Hardison, R; Xu, J; Jackson, J; Mansberger, J; Selifonova, O; Grotch, B; Biesecker, J; Petrykowska, H; Miller, W

    1993-01-01

    The rabbit homolog to the locus control region (LCR) of the human beta-like globin gene cluster was isolated, and long segments containing the DNase I hypersensitive sites (HS) were sequenced. The order and spacing of HS4, HS3, HS2 and HS1 are conserved between rabbit and human. Alignment of these sequences with their homologs from human, goat, and mouse shows that very long segments of DNA match between species, for over a thousand base pairs on either side of the previously identified functional cores, indicating that some important functions are found outside the cores. The activity of rabbit HS2 and HS3 was tested by attaching each to a novel reporter gene constructed by inserting the luciferase coding region into the rabbit epsilon-globin gene. In contrast to previous reports showing no effect of human or mouse HS3 on transient expression, both the rabbit HS2 and HS3 DNA fragments separately increased transient expression from the epsilon-luciferase hybrid gene and expression from stably integrated constructs in K562 erythroleukemia cells. PMID:8464710

  16. [Chronic knee joint discomfort].

    PubMed

    Wittke, R

    2005-06-23

    Chronic pain in the knee joint is frequently a sign of arthrosis in adults. This must be clearly differentiated from other knee problems. Patellofemoral stress syndrome (occurs mostly in young people) and arthritis with effusion in the knee joint after long and mostly unusual stress also allow only a reduced function of the knee joint. However, even when the knee joint is still fully functional, chronic problems could already exist: For example, for joggers, iliotibial band friction syndrome (runner's knee) or after high unphysiological stress, patellar tendinopathy (jumper's knee). These must be differentiated from pes anserinus syndrome and a plica mediopatellaris.

  17. Histological and biochemical characteristics of the rabbit anterior cruciate ligament in comparison to potential autografts.

    PubMed

    Hoyer, Mariann; Meier, Carola; Kohl, Benjamin; Lohan, Anke; Kokozidou, Maria; Schulze-Tanzil, Gundula

    2016-08-01

    Tissue engineering of an anterior cruciate ligament (ACL) implant with ACL cells requires detailed analysis of the tissue characteristics that should be mimicked. Therefore, we studied the histological and biochemical properties of rabbit derived ACLs in comparison to other knee-associated tendons that are used as autografts in men. Rabbit derived ACLs and Musculus (M.) semimembranosus, M. semitendinosus tendons and patellar ligaments were explanted from adult New Zealand white rabbits and analyzed histologically for tissue organization (e.g. cellularity, nuclear shapes, elastic fibers), total collagen and sulfated glycosaminoglycan (sGAG) contents. Gene expression analysis was performed for the main extracellular matrix (ECM) components type I collagen, decorin and the glycoprotein tenomodulin. The ACLs had a dimension of 1.39x0.39x0.1 cm in situ. They were characterized by high sGAG content in comparison to the other tendons/ligaments, whereas the total collagen content did not differ. ACLs possessed higher cellularity and lower feret diameter of the cell nuclei compared with the investigated rabbit-derived tendons. In ACLs long elastic fibers were observed. Concerning the gene expression level, lower transcription of tenomodulin was detected in the ACL compared with the other tendons, without significant difference in the decorin gene expression. The M. semitendinosus tendon had a significantly higher type I collagen expression than the ACL and the other investigated tendons. This phenotypical characterization of the lapine ACL presented in this study provides some key standards to evaluate tissue engineered ACL constructs to be tested in the rabbit model.

  18. A prospective study comparing attempted weight bearing in fiberglass below-knee casts and prefabricated pneumatic braces.

    PubMed

    Mason, Lyndon W; Dodds, Alex

    2010-04-01

    Partial weight bearing is commonly advised after fracture of the lower extremity. Research has determined this to be inaccurate both in its instruction and its reproducibility. Many trauma departments are commonly using alternatives to plaster in the splintage of fractures, such as fiberglass and the prefabricated pneumatic braces. This study's null hypothesis is that there is no difference between partial weight bearing through a fiberglass cast as compared with a pneumatic walker. A prospective study was conducted in our department including all patients who had metatarsal or ankle fractures and could partially weight bear. Patients were excluded if they were not allowed to bear weight, had received operative fixation of their fracture, or were younger than age 16 years. The patients' total weight was measured first, and then they were trained to place 50% of their weight through the splinted limb. Three measurements were taken of their attempted weight bearing at 50%, and they were blinded to the results. Over a 16-month period, 117 patients were enrolled for this study: 72 in the pneumatic walker group and 45 in the fiberglass group. There was no significant difference in sex, age, or fracture type. There was a significant difference in percentage of weight placed through the splinted limb, with the pneumatic brace group placing much greater force than the fiberglass group. This may have been caused by altered proprioception from the walker. It is important to realize this when prescribing partial weight bearing in a particular splint as this may result in avoidable complications.

  19. RABBIT POX

    PubMed Central

    Rosahn, Paul D.; Hu, Ch'uan-K'uei

    1935-01-01

    Observations on an epidemic of rabbit pox occurring in an isolated animal room during the winter of 1933–34 are reported. The clinical manifestations, consisting of a generalized papular eruption involving the skin and mucous membranes, together with blepharitis, ophthalmia, nasal discharge and lymphadenopathy were essentially similar to those noted in a pox epidemic of the previous year. This was true in general also of the pathological findings except that vacuolization, local necrosis and vesicle formation were seen in the epidermis, while in the previous year the microscopic pathology in the skin was confined to the corium. Evidence was presented indicating that the infection can be transmitted through the medium of a personal carrier, and that transmission in this manner can occur during the incubation period or before a definite diagnosis is possible. The findings also demonstrated that the etiological agents responsible for the disease reported here and that of the previous year were immunologically related, and that the immunity in recovered animals effectively persisted during the entire period for which data are available, 9 to 12 months. It appeared also that young animals suckling an immune doe were more refractory to the development of the lesions of rabbit pox than were the young of susceptible does. PMID:19870418

  20. Rabbit renotropic system

    SciTech Connect

    Areas, J.; Yun, G.C.; Rahmat, J.; Gersten, D.; Goel, R.; Preuss, H.G.

    1988-04-01

    Elevated levels of a specific renal growth factor, renotropin, have been associated with spontaneous hypertension. To examine this association more closely, we have undertaken the development of a better assay system to characterize and purify renotropin. Sera from rabbits prior to operation (control) and at a specified time after unilateral nephrectomy (uni) were examined for renotropic activity. Comparing the effects of uni to control sera in the same rabbit, significant stimulation of 3H-thymidine incorporation into the DNA of primary rabbit kidney cultures incubated in D-valine medium to eliminate fibroblast growth was noted: at 3 days postoperatively 73% (n = 13), at 7 days 103% (n = 39), at 10 days 130% (n = 31), at 21 days 101% (n = 24), at 42 days 89% (n = 13). All values were at least P less than 0.01. The stimulatory properties were dose-dependent but reached a plateau at high serum concentrations. Comparing CPM/mg protein in uni/control in different concentrations of sera 7 days postoperatively, uni versus control were 67/44 at 5% v/v, 139/72 at 10% v/v, 261/161 at 20% v/v, and 243/136 at 40% v/v. The renotropic effect of uni sera remained after dialysis in incubation medium and after sera were heated in boiling water for 5 minutes. Renal extracts obtained from growing kidneys 7 days postnephrectomy augmented renotropic activity. Atrial natriuretic factor, ouabain, PGF2 alpha, PGE1, and cAMP did not possess renotropic activity. We conclude that the primary rabbit kidney culture assay for renotropin is highly sensitive and will be an important tool to comprehend the role of renotropin in the pathogenesis of hypertension.

  1. Evaluation of electrosurgical meniscectomy in rabbits.

    PubMed

    Schosheim, P M; Caspari, R B

    1986-01-01

    Recently, electrosurgical cutting instruments utilizing radiofrequency energy have been designed as arthroscopic devices for cutting meniscal tissue. This study attempted to determine the in vivo gross and microscopic effects of radiofrequency energy on meniscal tissue in rabbits. Twelve adult New Zealand white rabbits (48 menisci) underwent bilateral knee arthrotomies. Ten rabbits (40 menisci) underwent partial meniscectomies in which one half of each meniscus in the longitudinal plane was removed with the electrosurgical generator. Two control rabbits underwent arthrotomy without resection of meniscal tissue. At specific time intervals, the rabbits were killed, and the menisci were removed. The gross specimens were photographed, and microscopic sections of each meniscus were fixed and stained. Specimens were evaluated to determine the cellular and vascular response to the electrosurgical cut edge of each meniscus. The microscopic specimens revealed that the radiofrequency cutting instruments produced a small degree of direct thermal damage to the cut meniscus. A tissue response producing a hypercellular dense collagen matrix was present for approximately 3 months. The spontaneous repair of tissue was complete by 6 months, and the histologic 6-month specimens could not be distinguished from the 6-month control specimens except with respect to the overall width of the specimens.

  2. Unicondylar knee arthroplasty: a cementless perspective

    PubMed Central

    Forsythe, Michael E.; Englund, Roy E.; Leighton, Ross K.

    2000-01-01

    Objective To compare the results of cementless unicondylar knee arthroplasty (UKA) with those already reported in a similar study on cemented UKA. Design A case-series cross-sectional study. Setting The Queen Elizabeth II Health Sciences Centre, Dalhousie University, Halifax. Patients Fifty-one patients who underwent a total of 57 UKAs between May 1989 and May 1997. Inclusion criteria were osteoarthritis involving the predominantly the medial compartment of the knee, relative sparing of the other compartments, less than 15° of varus, minimal knee instability, and attendance at the postoperative clinical visit. Intervention Cementless UKA. Main outcome measures Clinical parameters that included pain, range of motion and the Knee Society Clinical Knee Score. Roentgenographic parameters that included α, β, γ and σ angles and the presence of periprosthetic radiolucency or loose beads. Results Age, weight, gender and follow-up interval did not significantly affect the clinical results in terms of pain, range of motion or knee score. Knees with more than 1 mm of radiolucency had significantly lower knee scores than those with no radiolucency. Knees that radiologically had loose beads also had significantly lower knee scores. The clinical outcomes of cementless UKA were comparable to those already reported on cemented UKA. Cementless femurs had less radiolucency than the cemented femurs, whereas cementless tibias had more radiolucency than their cemented counterparts. Conclusions Cementless UKA seems to be as efficacious as cemented UKA. However, there is some concern about the amount of radiolucency in the cementless tibial components. A randomized clinical trial comparing both cementless and cemented tibial components with a cementless femur (hybrid knee) is needed to further assess this controversial issue in UKA. PMID:11129829

  3. A comparative study on the modes of action of TAK-438, a novel potassium-competitive acid blocker, and lansoprazole in primary cultured rabbit gastric glands.

    PubMed

    Matsukawa, Jun; Hori, Yasunobu; Nishida, Haruyuki; Kajino, Masahiro; Inatomi, Nobuhiro

    2011-05-01

    TAK-438 is a novel potassium-competitive acid blocker (P-CAB) type antisecretory agent that reversibly inhibits gastric H+, K+-ATPase. Previously, we showed that TAK-438 has superior efficacy compared to lansoprazole, a proton pump inhibitor, in the inhibition of acid secretion in vivo. In this study, we investigated the differences in the mode of actions of the two drugs using primary cultured rabbit gastric glands. TAK-438 and lansoprazole inhibited gastric acid formation in acutely isolated gastric glands (IC₅₀) values, 0.30 and 0.76 μM, respectively). In cultured gastric glands that were preincubated with TAK-438, the inhibitory effect on forskolin-stimulated acid formation was augmented over the incubation period, whereas the inhibitory effect of lansoprazole was not affected by time of incubation. Next, we evaluated the durations of the actions of TAK-438 and lansoprazole after gastric glands were incubated with either drug for 2h followed by washout. Even 8h after the drug washout, TAK-438 at higher concentrations inhibited acid formation, but the inhibitory effect of lansoprazole disappeared immediately after washout. Additionally, only a small amount of [¹⁴C] lansoprazole accumulated in resting glands, and this accumulation was enhanced by treatment with 1 μM of forskolin. In contrast, high levels of [¹⁴C] TAK-438 accumulated in both resting and forskolin-treated glands. Furthermore, a 2-h preincubation followed by washout demonstrated a slow clearance of [¹⁴C] TAK-438 from the glands. These findings suggest that TAK-438 exerts a longer and more potent antisecretory effect than lansoprazole as a result of its high accumulation and slow clearance from the gastric glands.

  4. The discovery of the synovial lymphatic stomata and lymphatic reabsorption in knee effusion.

    PubMed

    Ping, Zepeng; Jiang, Tingting; Wang, Chong; Chen, Zhongyi; Chen, Zhongliang; Wang, Jiaxiong; Wang, Li; Wang, Beibei; Xu, Dandan; Liu, Changming; Li, Zhongjie; Li, Ji-Cheng

    2015-06-01

    To illustrate the mechanism of lymphatic reabsorption in knee joint effusion. The current investigation employed transmission electron microscopy (TEM) and scanning electron microscopy (SEM) techniques to reveal the ultrastructure of the knee synovial membrane in New Zealand rabbits and human. Ultrastructural changes of the synovial lymphatic stomata were observed by using trypan blue absorption and sodium hydroxide (NaOH) digestion methods, and the animal models of synovitis. New Zealand rabbits and human synovial membranes were composed of two types of synovial cells: type A and type B. No lymphatic stomata were found among type A synovial cells, whereas lymphatic stomata with the diameters ranging 0.74-3.26 µm were found in type B synovial cells, and some stomata were closed. After the NaOH digestion, a number of sieve pores, similar to lymphatic stomata in size and shape, were observed in the dense fibrous connective tissue underneath the type B synovial cells. After injecting trypan blue into the rabbit knee joint cavity, absorption of trypan blue through the lymphatic stomata was observed, suggesting the absorption function of the synovial lymphatic stomata. In the rabbit knee joint synovitis models, the synovial lymphatic stomata diameter enlarged. Some macrophages migrated from the lymphatic stomata, indicating that the synovial lymphatic stomata were involved in the joint effusion absorption and inflammatory response. Our study is the first to report the existence of synovial lymphatic stomata in the New Zealand rabbits and human knee joints. Lymphatic stomata may have an important role in the reabsorption of joint effusion.

  5. [A comparative evaluation of the oxidant and antioxidant blood systems in rabbits with caustic burns of the eyes in their treatment by synthetic and natural antioxidants].

    PubMed

    Travkin, A G; Shul'gina, N A

    2004-01-01

    A method of provoking a caustic burn was described on the basis of experiments made in 36 rabbits (72 eyes) who were shared between 2 groups. Effects from histochrom, a natural antioxidant, and from emoxipin, a synthetic antioxidant, produced on the lipid-peroxidation parameters at early stages of ocular burn disease were studied. A higher clinical efficiency of histochrom versus emoxipin was demonstrated.

  6. Increased interleukin 6 and tumour necrosis factor α expression in the infrapatellar fat pad of the knee joint with the anterior knee pain syndrome: a preliminary report.

    PubMed

    Witoński, Dariusz; Wągrowska-Danilewicz, Małgorzata; Kęska, Rafał; Raczyńska-Witońska, Grażyna; Stasikowska-Kanicka, Olga

    2010-01-01

    The pathway of pain in the anterior knee pain syndrome remains unclear. It has been hypothesized that some biochemical mediators of inflammation, such as cytokines contribute to the process. The objective of this work was to evaluate the synovial membrane and the infrapatellar fat pad expression of the inflammatory mediators and potentially chondrodestructive cytokines interleukin 6 (IL-6) and tumour necrosis factor α (TNF-α) in the anterior knee pain syndrome, and to determine whether the cytokine expression counterpart with/corresponds to the amount of chondral damage in this syndrome. Ten consecutive patients with the anterior knee pain syndrome (group I) participated in the study. Patients with a history of trauma were excluded from this group. For comparison we used 10 patients with anterior cruciate ligament rupture or meniscal lesion with no history of pain in the anterior compartment (group II). Immunohistochemical techniques using a polyclonal rabbit anti-human antibody to IL-6 and a monoclonal mouse anti-human antibody to TNF-α were employed. The results show a statistically significant higher expression of IL-6 in infrapatellar fat pad (p < 0.05) as well as TNF-α in the infrapatellar fad pad and the synovium (p < 0.03, and p < 0.02, respectively) in group I as compared to control subjects. There is no any difference in the amount of chondral damage present in group I as compared to group II. The results of this study provide the immunohistochemical evidence suggesting that the anterior knee pain syndrome could be characterized by infrapatellar fat pad and synovial inflammation variations without the articular cartilage loss.

  7. Anterior knee pain and cold knees: a possible association in women.

    PubMed

    Selfe, James; Sutton, Chris; Hardaker, Natalie J; Greenhalgh, Sue; Karki, Anne; Dey, Paola

    2010-10-01

    Abnormal reactions to environmental cold have been observed in some patients with Anterior Knee Pain (AKP). The aims of this study were to investigate whether palpation of the knee could classify patients into those with and those without cold knees; whether this classification could be objectively validated using thermal imaging; whether the cold and not cold knee groups varied in response to a cold stress test and in patient-reported measures. Fifty eight patients were recruited; palpation classified them into cold and not cold groups. Twenty-one (36%) patients were classified as having a cold knee by palpation: fourteen (36%) females and seven males (37%). Preliminary analysis suggested gender might be an effect modifier and the number of men was small, therefore the analysis focussed on females. Women with cold knees had a significantly smaller patellar skin fold, lower levels of activity and worse scores on the MFIQ, there also appeared to be an association with a traumatic onset. Women with cold knees were more likely to report cold weather affected their knees and they preferred a hot water bottle compared to an ice-pack on their knee; there was also a trend towards having to wear extra tights/long johns in the winter. This study has helped to define a clinical profile for a group of females with AKP and cold knees. This group appears to demonstrate a mild form of Reflex Sympathetic Dystrophy.

  8. Effect of implant design on knee flexion.

    PubMed

    Dennis, Douglas A; Heekin, R David; Clark, Charles R; Murphy, Jeffrey A; O'Dell, Tammy L; Dwyer, Kimberly A

    2013-03-01

    From March 2006 to August 2008, 93 subjects (186 knees) underwent simultaneous bilateral total knee arthroplasty performed by eight surgeons at North American centers. This randomized study was conducted to determine whether non-weight-bearing passive flexion was superior for knees receiving a posterior stabilized high flexion device compared to a posterior stabilized standard device in the contra-lateral knee. Weight-bearing single leg active flexion was one secondary endpoint. Follow-up compliance was 92.5%. Results show small, but significant superiority in the motion metrics for the high flexion device compared to the standard device 12 months after surgery, especially for a subgroup of patients with pre-operative flexion less than 120° in both knees. Thus, the ideal candidate for the high flexion device may be one with lesser pre-operative flexion.

  9. Anterior cruciate ligament surgery in the rabbit

    PubMed Central

    2013-01-01

    Background Various methods regarding allograft knee replacements have been described. The animal models, which are generally used for this purpose include sheep, dogs, goats, and pigs, and accrue significant costs for study protocols. The authors herein describe an efficient and cost-effective model to study either native or tissue-engineered allografts for anterior cruciate ligament (ACL) replacement in a New Zealand rabbit model with the potential for transgenic and cell migration studies. Methods ACL reconstructions were performed in rabbits under general anesthesia. For fresh allograft implantations, two animals were operated in parallel. Each right extensor digitorum longus tendon was harvested and prepared for implantation. After excision of the ACL, tibial and femoral bone tunnels were created to implant each graft in the native ACL position. Results During a 2-year period, the authors have successfully undertaken this surgery in 61 rabbits and have not noticed any major complications attributed to this surgical technique. In addition, the authors have observed fast recovery in the animals postoperatively. Conclusion The authors recommend this surgical procedure as an excellent model for the study of knee surgery. PMID:23957941

  10. EFFECTS OF THE GENIUM MICROPROCESSOR KNEE SYSTEM ON KNEE MOMENT SYMMETRY DURING HILL WALKING

    PubMed Central

    Highsmith, M. Jason; Klenow, Tyler D.; Kahle, Jason T.; Wernke, Matthew M.; Carey, Stephanie L.; Miro, Rebecca M.; Lura, Derek J.

    2016-01-01

    Use of the Genium microprocessor knee (MPK) system reportedly improves knee kinematics during walking and other functional tasks compared to other MPK systems. This improved kinematic pattern was observed when walking on different hill conditions and at different speeds. Given the improved kinematics associated with hill walking while using the Genium, a similar improvement in the symmetry of knee kinetics is also feasible. The purpose of this study was to determine if Genium MPK use would reduce the degree of asymmetry (DoA) of peak stance knee flexion moment compared to the C-Leg MPK in transfemoral amputation (TFA) patients. This study used a randomized experimental crossover of TFA patients using Genium and C-Leg MPKs (n = 20). Biomechanical gait analysis by 3D motion tracking with floor mounted force plates of TFA patients ambulating at different speeds on 5° ramps was completed. Knee moment DoA was significantly different between MPK conditions in the slow and fast uphill as well as the slow and self-selected downhill conditions. In a sample of high-functioning TFA patients, Genium knee system accommodation and use improved knee moment symmetry in slow speed walking up and down a five degree ramp compared with C-Leg. Additionally, the Genium improved knee moment symmetry when walking downhill at comfortable speed. These results likely have application in other patients who could benefit from more consistent knee function, such as older patients and others who have slower walking speeds. PMID:28066523

  11. EFFECTS OF THE GENIUM MICROPROCESSOR KNEE SYSTEM ON KNEE MOMENT SYMMETRY DURING HILL WALKING.

    PubMed

    Highsmith, M Jason; Klenow, Tyler D; Kahle, Jason T; Wernke, Matthew M; Carey, Stephanie L; Miro, Rebecca M; Lura, Derek J

    2016-09-01

    Use of the Genium microprocessor knee (MPK) system reportedly improves knee kinematics during walking and other functional tasks compared to other MPK systems. This improved kinematic pattern was observed when walking on different hill conditions and at different speeds. Given the improved kinematics associated with hill walking while using the Genium, a similar improvement in the symmetry of knee kinetics is also feasible. The purpose of this study was to determine if Genium MPK use would reduce the degree of asymmetry (DoA) of peak stance knee flexion moment compared to the C-Leg MPK in transfemoral amputation (TFA) patients. This study used a randomized experimental crossover of TFA patients using Genium and C-Leg MPKs (n = 20). Biomechanical gait analysis by 3D motion tracking with floor mounted force plates of TFA patients ambulating at different speeds on 5° ramps was completed. Knee moment DoA was significantly different between MPK conditions in the slow and fast uphill as well as the slow and self-selected downhill conditions. In a sample of high-functioning TFA patients, Genium knee system accommodation and use improved knee moment symmetry in slow speed walking up and down a five degree ramp compared with C-Leg. Additionally, the Genium improved knee moment symmetry when walking downhill at comfortable speed. These results likely have application in other patients who could benefit from more consistent knee function, such as older patients and others who have slower walking speeds.

  12. Six degree-of-freedom knee joint kinematics in obese individuals with knee pain during gait

    PubMed Central

    Li, Jing-Sheng; Tsai, Tsung-Yuan; Felson, David T.; Li, Guoan; Lewis, Cara L.

    2017-01-01

    Knee joint pain is a common symptom in obese individuals and walking is often prescribed as part of management programs. Past studies in obese individuals have focused on standing alignment and kinematics in the sagittal and coronal planes. Investigation of 6 degree-of-freedom (6DOF) knee joint kinematics during standing and gait is important to thoroughly understand knee function in obese individuals with knee pain. This study aimed to investigate the 6DOF knee joint kinematics in standing and during gait in obese patients using a validated fluoroscopic imaging system. Ten individuals with obesity and knee pain were recruited. While standing, the knee was in 7.4±6.3°of hyperextension, 2.8±3.3° of abduction and 5.6±7.3° of external rotation. The femoral center was located 0.7±3.1mm anterior and 5.1±1.5mm medial to the tibial center. During treadmill gait, the sagittal plane motion, i.e., flexion/extension and anterior-posterior translation, showed a clear pattern. Specifically, obese individuals with knee pain maintained the knee in more flexion and more anterior tibial translation during most of the stance phase of the gait cycle and had a reduced total range of knee flexion when compared to a healthy non-obese group. In conclusion, obese individuals with knee pain used hyperextension knee posture while standing, but maintained the knee in more flexion during gait with reduced overall range of motion in the 6DOF analysis. PMID:28339477

  13. Human knee joint anatomy revisited: morphometry in the light of sex-specific total knee arthroplasty.

    PubMed

    Dargel, Jens; Michael, Joern W P; Feiser, Janna; Ivo, Roland; Koebke, Juergen

    2011-04-01

    This study investigates differences in the anatomy of male and female knee joints to contribute to the current debate on sex-specific total knee implants. Morphometric data were obtained from 60 human cadaver knees, and sex differences were calculated. All data were corrected for height, and male and female specimens presenting with an identical length of the femur were analyzed as matched pairs. Male linear knee joint dimensions were significantly larger when compared with females. When corrected for differences in height, medial-lateral dimensions of male knees were significantly larger than female; however, matched paired analysis did not prove these differences to be consistent. Although implant design should focus interindividual variations in knee joint anatomy, our data do not support the concept of a female-specific implant design.

  14. Knee range of motion after total knee arthroplasty: how important is this as an outcome measure?

    PubMed

    Miner, Andrew L; Lingard, Elizabeth A; Wright, Elizabeth A; Sledge, Clement B; Katz, Jeffrey N

    2003-04-01

    We investigated the relationship of knee range of motion (ROM) and function in a prospective, observational study of primary total knee arthroplasty (TKA). Preoperative and 12-month data were collected on 684 patients, including knee ROM, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and function questionnaire scores, patient satisfaction, and perceived improvement in quality of life (QOL). Only modest correlations were found between knee ROM and WOMAC function (r<0.34). At 12 months we found significantly worse WOMAC function scores for patients with <95 degrees flexion compared with patients with > or =95 degrees (mean, 61.9 vs 75.0; P<.0001). In linear regression models, WOMAC pain and function scores at 12 months were both correlates of patient satisfaction and perceived improvement in QOL (standardized beta>3.5; P<.0001), but knee flexion was not. For assessment of these outcomes, WOMAC function appears to be more important than knee flexion.

  15. The effect of in situ freezing on rabbit patellar tendon. A histologic, biochemical, and biomechanical analysis

    NASA Technical Reports Server (NTRS)

    Graf, B. K.; Fujisaki, K.; Vanderby, R. Jr; Vailas, A. C.

    1992-01-01

    Cell necrosis has been well documented as one of the many changes that occur in autogenous tendon when it is used to reconstruct the anterior cruciate ligament. The purpose of this experiment was to isolate cell necrosis as a variable and study its effect on the patellar tendon. To accomplish this, both knees of 25 New Zealand White rabbits were operated on. In one knee, a 5-mm wide band of patellar tendon was subjected to two rapid freeze-thaw cycles, while the other knee underwent sham surgery. Histologic evaluation showed a zone of necrosis at 2 and 4 weeks with cellular repopulation complete at 8 weeks. patellar tendon cross-sectional area was 0.118 cm2 at 8 weeks for the frozen specimens compared to 0.102 cm2 for the sham-operated controls. This difference was significant at the P = 0.025 level. Mechanical testing at 4 and 8 weeks revealed no significant changes in tendon length, maximum load, or stiffness. The collagen content was also unchanged at both 4 and 8 weeks.

  16. A comparative study of red and blue light-emitting diodes and low-level laser in regeneration of the transected sciatic nerve after an end to end neurorrhaphy in rabbits.

    PubMed

    Takhtfooladi, Mohammad Ashrafzadeh; Sharifi, Davood

    2015-12-01

    This study aimed at evaluating the effects of red and blue light-emitting diodes (LED) and low-level laser (LLL) on the regeneration of the transected sciatic nerve after an end-to-end neurorrhaphy in rabbits. Forty healthy mature male New Zealand rabbits were randomly assigned into four experimental groups: control, LLL (680 nm), red LED (650 nm), and blue LED (450 nm). All animals underwent the right sciatic nerve neurotmesis injury under general anesthesia and end-to-end anastomosis. The phototherapy was initiated on the first postoperative day and lasted for 14 consecutive days at the same time of the day. On the 30th day post-surgery, the animals whose sciatic nerves were harvested for histopathological analysis were euthanized. The nerves were analyzed and quantified the following findings: Schwann cells, large myelinic axons, and neurons. In the LLL group, as compared to other groups, an increase in the number of all analyzed aspects was observed with significance level (P < 0.05). This finding suggests that postoperative LLL irradiation was able to accelerate and potentialize the peripheral nerve regeneration process in rabbits within 14 days of irradiation.

  17. Micro-morphometrical assessment of the effect of Harpagophytum procumbens extract on articular cartilage in rabbits with experimental osteoarthritis using magnetic resonance imaging.

    PubMed

    Wachsmuth, L; Lindhorst, E; Wrubel, S; Hadzhiyski, H; Hudelmaier, M; Eckstein, F; Chrubasik, S

    2011-08-01

    In vitro effects indicate a putative beneficial effect of Harpagophytum procumbens on cartilage turnover, however, in vivo protective effects on cartilage have yet to be demonstrated. A 7.1T MRI scanner was used to derive measurements of thickness, surface area and volume of the tibial condylar cartilage and to assess their precision (in the case of volume also accuracy) against the volumes of dissected cartilage measured by water displacement. Quantitative measurements were made in 16 rabbits, 6 months after unilateral medial meniscectomy and transection of the anterior cruciate ligament, after which eight of these were given a proprietary extract of Harpagophytum procumbens (HP). A semiquantitative MRI-based grading of the tibial cartilage was also compared with a 'macroscopic' grading based on direct visual inspection of dissected joints. The test-retest precision for MRI-based measurement was ≤6.4%. MRI-based measurements correlated well with volumes of surgically resected cartilage (r =  0.97, pair-wise random difference 4.2%). The medial tibial cartilage thickness and volume were about 35% smaller in the operated knees than in the non-operated contralateral knees (p < 0.05). The findings suggest that MRI is a precise and accurate tool for evaluating cartilage in a rabbit model of OA. The difference between the intact and operated knee in thickness and volume of the medial tibial cartilage was slightly but not significantly smaller in the HP-treated group than in the non-treated group.

  18. Viral infections of rabbits.

    PubMed

    Kerr, Peter J; Donnelly, Thomas M

    2013-05-01

    Viral diseases of rabbits have been used historically to study oncogenesis (e.g. rabbit fibroma virus, cottontail rabbit papillomavirus) and biologically to control feral rabbit populations (e.g. myxoma virus). However, clinicians seeing pet rabbits in North America infrequently encounter viral diseases although myxomatosis may be seen occasionally. The situation is different in Europe and Australia, where myxomatosis and rabbit hemorrhagic disease are endemic. Advances in epidemiology and virology have led to detection of other lapine viruses that are now recognized as agents of emerging infectious diseases. Rabbit caliciviruses, related to rabbit hemorrhagic disease, are generally avirulent, but lethal variants are being identified in Europe and North America. Enteric viruses including lapine rotavirus, rabbit enteric coronavirus and rabbit astrovirus are being acknowledged as contributors to the multifactorial enteritis complex of juvenile rabbits. Three avirulent leporid herpesviruses are found in domestic rabbits. A fourth highly pathogenic virus designated leporid herpesvirus 4 has been described in Canada and Alaska. This review considers viruses affecting rabbits by their clinical significance. Viruses of major and minor clinical significance are described, and viruses of laboratory significance are mentioned.

  19. Unicompartmental Knee Osteoarthritis (UKOA): Unicompartmental Knee Arthroplasty (UKA) or High Tibial Osteotomy (HTO)?

    PubMed Central

    Rodriguez-Merchan, E. Carlos

    2016-01-01

    The aim of this review article is to analyze the results of high tibial osteotomy compared to unicompartmental knee arthroplasty in patients with unicompartmental knee osteoarthritis. The search engine used was PubMed. The keywords were: “high tibial osteotomy versus unicompartmental knee arthroplasty”. Twenty-one articles were found on 28 February 2015, but only eighteen were selected and reviewed because they strictly focused on the topic. In a meta-analysis the ratio for an excellent outcome was higher in unicompartmental knee arthroplasty than high tibial osteotomy and the risks of revision and complications were lower in the former. A prospective comparative study showed that unicompartmental knee arthroplasty offers better long-term success (77% for unicompartmental knee arthroplasty and 60% for high tibial osteotomy at 7-10 years). However, a review of the literature showed no evidence of superior results of one treatment over the other. A multicenter study stated that unicompartmental knee osteoarthritis without constitutional deformity should be treated with unicompartmental knee arthroplasty while in cases with constitutional deformity high tibial osteotomy should be indicated. A case control study stated that unicompartmental knee arthroplasty offers a viable alternative to high tibial osteotomy if proper patient selection is done. The literature is still controversial regarding the best surgical treatment for unicompartmental knee osteoarthritis (high tibial osteotomy or unicompartmental knee arthroplasty). However, unicompartmental knee arthroplasty utilization is increasing, while high tibial osteotomy utilization is decreasing, and a meta-analysis has shown better outcomes and less risk of revision and complications in the former. A systematic review has found that with correct patient selection, both procedures show effective and reliable results. However, prospective randomized studies are needed in order to answer the question of this article

  20. Knee Bracing: What Works?

    MedlinePlus

    ... that make knee braces claim that their products work well. Scientific studies have not completely agreed. It's not clear what the knee braces actually do. Braces often work better in the laboratory than they do in ...

  1. Partial knee replacement - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100225.htm Partial knee replacement - series—Normal anatomy To use the sharing ... A.M. Editorial team. Related MedlinePlus Health Topics Knee Replacement A.D.A.M., Inc. is accredited ...

  2. Preventing Knee Injuries

    MedlinePlus

    ... as a result of a twisting or pivoting motion. This injury may cause susceptibility to repeat injuries and knee instability, and therefore often requires surgery. Occasionally, a twisting or hyperextension force to the knee may result in a tibial ...

  3. Knee arthroscopy - discharge

    MedlinePlus

    ... remove it. Torn or damaged anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) Inflamed or damaged ... surgery Knee pain Meniscal allograft transplantation Patient Instructions ACL reconstruction - discharge Getting your home ready - knee or ...

  4. Microprocessor prosthetic knees.

    PubMed

    Berry, Dale

    2006-02-01

    This article traces the development of microprocessor prosthetic knees from early research in the 1970s to the present. Read about how microprocessor knees work, functional options, patient selection, and the future of this prosthetic.

  5. Knee braces - unloading

    MedlinePlus

    ... in their knees, they are referring to a type of arthritis called osteoarthritis . Osteoarthritis is caused by wear and tear inside your knee joints. Cartilage, the firm, rubbery tissue that cushions all of ...

  6. Examining the knee joint.

    PubMed

    Monk, Daniel

    2013-04-01

    Appropriate history taking and examination can ensure accurate diagnosis of common knee problems, and rapid and effective interventions or referral to orthopaedic specialists. This article describes the anatomy of the knee joint and discusses relevant history taking, the examination process, special tests and radiology, as well as common knee injuries and their management.

  7. Knee disarticulation after total-knee replacement.

    PubMed

    Lambregts, S A M; Hitters, W M G C

    2002-12-01

    An 89-year-old woman who had a total-knee replacement in the past, underwent a knee disarticulation of the same leg because of an ischaemic foot. Eight (8) months postoperatively the stump is fully weight-bearing and the patient is able to walk safely, using a prosthesis and a walking frame.

  8. Knee Lymphocutaneous Fistula Secondary to Knee Arthroplasty

    PubMed Central

    Pérez-de la Fuente, T.; Sandoval, E.; Alonso-Burgos, A.; García-Pardo, L.; Cárcamo, C.; Caballero, O.

    2014-01-01

    Lower limb lymphorrhea secondary to a surgical procedure is a rare but difficult-to-solve complication. In lower limb, this entity is frequently associated with vascular procedures around the inguinal area. We report on a case of a knee lymphocutaneous fistula secondary to a knee revision arthroplasty. To our knowledge, no previous reports regarding this complication have been published. PMID:25580333

  9. Are Ultrasound-Guided Ophthalmic Blocks Injurious to the Eye? A Comparative Rabbit Model Study of Two Ultrasound Devices Evaluating Intraorbital Thermal and Structural Changes

    PubMed Central

    Palte, Howard D.; Gayer, Steven; Arrieta, Esdras; Shaw, Eric Scot; Nose, Izuru; Lee, Elizabete; Arheart, Kristopher L.; Dubovy, Sander; Birnbach, David J.; Parel, Jean-Marie

    2012-01-01

    Background Since Atkinson’s original description of retrobulbar block in 1936, needle-based anesthetic techniques have become integral to ophthalmic anesthesia. These techniques are unfortunately associated with rare, grave complications such as globe perforation. Ultrasound has gained widespread acceptance for peripheral nerve blockade but its translation to ocular anesthesia has been hampered because sonic energy, in the guise of thermal or biomechanical insult, is potentially injurious to vulnerable eye tissue. The United States Food and Drug Administration have defined guidelines for safe use of ultrasound for ophthalmic examination but most ultrasound devices used by anesthesiologists are not Food and Drug Administration-approved for ocular application because they generate excessive energy. Regulating agencies state that ultrasound examination can be safely undertaken as long as tissue temperatures do not increase >1.5°C above physiological levels. Methods Using a rabbit model, we investigated the thermal and mechanical ocular effects after prolonged ultrasonic exposure to single orbital and non-orbital-rated devices. In a dual-phase study, aimed at detecting ocular injury, the eyes of 8 rabbits were exposed to continuous 10-minute ultrasound examinations from two devices: 1) the Sonosite Micromaxx (non-orbital-rated) and 2) the Sonomed VuMax (orbital-rated) machines. In Phase I temperatures were continuously monitored via thermocouples implanted within specific eye structures (n=4). In Phase II the eyes were subjected to ultrasonic exposure without surgical intervention (n=4). All eyes underwent light microscopy examinations followed, at different intervals, by histology evaluations conducted by an ophthalmic pathologist. Results Temperature changes were monitored in the eyes of four rabbits. The non-orbital-rated transducer produced increases in ocular tissue temperature that surpassed the safe limit (increases> 1.50C ) in the lens of three rabbits (at 5

  10. Kinematic Analysis of a Posterior-stabilized Knee Prosthesis

    PubMed Central

    Zhao, Zhi-Xin; Wen, Liang; Qu, Tie-Bing; Hou, Li-Li; Xiang, Dong; Bin, Jia

    2015-01-01

    Background: The goal of total knee arthroplasty (TKA) is to restore knee kinematics. Knee prosthesis design plays a very important role in successful restoration. Here, kinematics models of normal and prosthetic knees were created and validated using previously published data. Methods: Computed tomography and magnetic resonance imaging scans of a healthy, anticorrosive female cadaver were used to establish a model of the entire lower limbs, including the femur, tibia, patella, fibula, distal femur cartilage, and medial and lateral menisci, as well as the anterior cruciate, posterior cruciate, medial collateral, and lateral collateral ligaments. The data from the three-dimensional models of the normal knee joint and a posterior-stabilized (PS) knee prosthesis were imported into finite element analysis software to create the final kinematic model of the TKA prosthesis, which was then validated by comparison with a previous study. The displacement of the medial/lateral femur and the internal rotation angle of the tibia were analyzed during 0–135° flexion. Results: Both the output data trends and the measured values derived from the normal knee's kinematics model were very close to the results reported in a previous in vivo study, suggesting that this model can be used for further analyses. The PS knee prosthesis underwent an abnormal forward displacement compared with the normal knee and has insufficient, or insufficiently aggressive, “rollback” compared with the lateral femur of the normal knee. In addition, a certain degree of reverse rotation occurs during flexion of the PS knee prosthesis. Conclusions: There were still several differences between the kinematics of the PS knee prosthesis and a normal knee, suggesting room for improving the design of the PS knee prosthesis. The abnormal kinematics during early flexion shows that the design of the articular surface played a vital role in improving the kinematics of the PS knee prosthesis. PMID:25591565

  11. High Knee Valgus in Female Subjects Does Not Yield Higher Knee Translations During Drop Landings: A Biplane Fluoroscopic Study

    PubMed Central

    Torry, Michael R.; Shelburne, Kevin B.; Myers, Casey; Giphart, J. Erik; Pennington, W. Wesley; Krong, Jacob P.; Peterson, Daniel S.; Steadman, J. Richard; Woo, Savio L-Y.

    2012-01-01

    The goal of this study was to determine the effects of peak knee valgus angle and peak knee abductor moment on the anterior, medial, and lateral tibial translations (ATT, MTT, LTT) in the ‘at risk’ female knee during drop landing. Fifteen female subjects performed drop landings from 40 cm. 3D knee motion was simultaneously recorded using a high speed, biplane fluoroscopy system and a video-based motion analysis system. Valgus knee angles and knee abduction moments were stratified into low, intermediate and high groups and peak ATT, MTT and LTT were compared between these groups with ANOVA (α = .05). Significant differences were observed between stratified groups in peak knee valgus angle (p < .0001) and peak knee abduction moment (p < .0001). However, no corresponding differences in peak ATT, LTT and MTT between groups exhibiting low to high peak knee valgus angles (ATT: p = .80; LTT: p = .25; MTT: p = .72); or, in peak ATT (p = .61), LTT (p = .26) and MTT (p = .96) translations when stratified according to low to high knee abduction moments, were found. We conclude that the healthy female knee is tightly regulated with regard to translations even when motion analysis derived knee valgus angles and abduction moments are high. PMID:22968826

  12. High knee valgus in female subjects does not yield higher knee translations during drop landings: a biplane fluoroscopic study.

    PubMed

    Torry, Michael R; Shelburne, Kevin B; Myers, Casey; Giphart, J Erik; Pennington, W Wesley; Krong, Jacob P; Peterson, Daniel S; Steadman, J Richard; Woo, Savio L-Y

    2013-02-01

    The goal of this study was to determine the effects of peak knee valgus angle and peak knee abductor moment on the anterior, medial, and lateral tibial translations (ATT, MTT, LTT) in the "at risk" female knee during drop landing. Fifteen female subjects performed drop landings from 40 cm. Three-dimension knee motion was simultaneously recorded using a high speed, biplane fluoroscopy system, and a video-based motion analysis system. Valgus knee angles and knee abduction moments were stratified into low, intermediate, and high groups and peak ATT, MTT, and LTT were compared between these groups with ANOVA (α = 0.05). Significant differences were observed between stratified groups in peak knee valgus angle (p < 0.0001) and peak knee abduction moment (p < 0.0001). However, no corresponding differences in peak ATT, LTT, and MTT between groups exhibiting low to high-peak knee valgus angles (ATT: p = 0.80; LTT: p = 0.25; MTT: p = 0.72); or, in peak ATT (p = 0.61), LTT (p = 0.26) and MTT (p = 0.96) translations when stratified according to low to high knee abduction moments, were found. We conclude that the healthy female knee is tightly regulated with regard to translations even when motion analysis derived knee valgus angles and abduction moments are high.

  13. Asymmetric loading and bone mineral density at the asymptomatic knees of subjects with unilateral hip osteoarthritis

    PubMed Central

    Shakoor, Najia; Dua, Anisha; Thorp, Laura; Mikolaitis, Rachel A.; Wimmer, Markus A.; Foucher, Kharma C.; Fogg, Louis F.; Block, Joel A.

    2011-01-01

    Objective The contralateral knee of those with unilateral endstage hip OA is known to be at greater risk for endstage knee OA compared to the ipsilateral, same side knee. Likewise, in endstage hip OA, this contralateral knee is known to have increased dynamic joint loads compared to the ipsilateral knee. Here, we study a population with unilateral hip OA, who are asymptomatic at the knees, for early asymmetries in knee loading. Methods Data from 62 subjects with unilateral hip OA were evaluated. Subjects underwent gait analyses for evaluation of dynamic knee loads as well as dual energy X-ray absorptiometry for evaluation of bone mineral density (BMD) at both knees. Differences between knees were compared. Results Peak dynamic knee loads were significantly higher at the contralateral knee compared to the ipsilateral knee (2.46±0.71 vs 2.23±0.81 %BW*ht, p=0.029). Similarly, medial compartment tibial BMD was significantly higher at the contralateral knee compared to the ipsilateral knee (0.897±0.208 vs 0.854±0.206 gm/c2, p=0.033). Interestingly, there was a direct correlation between contralteral:ipsilateral dynamic knee load and contralateral:ipsilateral medial compartment tibial BMD (Spearman’s rho= 0.287, p=0.036). Conclusions This study demonstrates that at the contralateral knees of patients with unilateral hip OA, which are at higher risk of developing progressive symptomatic OA compared to the ipsilateral knees, loading and structural asymmetries appear early in the disease course, while the knees are still asymptomatic. These early biomechanical asymmetries may have corresponding long term consequences, providing further support for the potential role of loading in OA onset and progression. PMID:22127702

  14. Antibacterial activity of joint fluid in cemented total-knee arthroplasty: an in vivo comparative study of polymethylmethacrylate with and without antibiotic loading.

    PubMed

    Ueng, Steve W N; Hsieh, Pang-Hsin; Shih, Hsin-Nung; Chan, Yi-Shan; Lee, Mel S; Chang, Yuhan

    2012-11-01

    The objective of this study was to evaluate the antibacterial activities of joint fluids of patients undergoing total-knee arthroplasty (TKA). Thirty patients who were scheduled for primary cemented TKA were enrolled in the study. The patients were grouped on the basis of whether the cement was without antibiotic loading (control group) or loaded with oxacillin (oxacillin group) or vancomycin (vancomycin group). Cefazolin was administered to every patient as the perioperative prophylactic antibiotic. Samples of joint fluids were collected from the knee joints at 8, 16, 24, 32, 40, and 48 h after prosthesis implantation. We assessed the bioactivities of the joint fluids against methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA). The antibiotic contents of the joint fluid samples were further evaluated by using high-performance liquid chromatography. Against MSSA, all joint fluid samples exhibited at least 24 h of bacterial inhibition activity. The oxacillin (43.2 h ± 2 h) and vancomycin (40.8 h ± 1.8 h) groups exhibited significantly longer durations of antibacterial activities than the control group (28 h ± 1.3 h; P < 0.05). However, antibacterial activity against MRSA was observed only in the vancomycin group. In conclusion, cefazolin, which was administered as a prophylactic antibiotic in TKA, exhibited good ability for knee joint penetration and was sufficient to inhibit MSSA during its administration. The use of antibiotic-loaded cement can prolong the antibacterial activity of joint fluid in TKA. Further, vancomycin-loaded cement had antibacterial activity against MRSA superior to that of cement loaded with oxacillin or without antibiotic loading.

  15. Knee joint functional range of movement prior to and following total knee arthroplasty measured using flexible electrogoniometry.

    PubMed

    Myles, Christine M; Rowe, Philip J; Walker, Colin R C; Nutton, Richard W

    2002-08-01

    The functional ranges of movement of the knee were investigated in a group of patients with knee osteoarthritis (n = 42, mean age 70 years) before, 4 months and at 18-24 months after total knee arthroplasty and then compared with age matched normal subjects (n = 20, mean age 67 years). Flexible electrogoniometry was used to record the maximum flexion-extension angle, the minimum flexion-extension angle and flexion-extension excursions of both knees during eleven functional activities along with the active and passive knee joint range of motion measured using a manual goniometer. Over the eleven functional activities the patients pre-operatively exhibited 28% less knee joint excursion than normal age matched subjects. By 18-24 months following total knee arthroplasty only 2% of this deficit was recovered. Statistically this recovery was only significant in level walking, slope ascent and slope descent. A greater range of movement was measured in a non-weight bearing position than was used in weight bearing functional activity. It is concluded that total knee arthroplasty gives rise to little improvement in knee motion during functional activities and that functional range of movement of the knee remains limited when compared to normal knee function for a minimum of 18 months following operation.

  16. Soft tissue artifact compensation in knee kinematics by multi-body optimization: Performance of subject-specific knee joint models.

    PubMed

    Clément, Julien; Dumas, Raphaël; Hagemeister, Nicola; de Guise, Jaques A

    2015-11-05

    Soft tissue artifact (STA) distort marker-based knee kinematics measures and make them difficult to use in clinical practice. None of the current methods designed to compensate for STA is suitable, but multi-body optimization (MBO) has demonstrated encouraging results and can be improved. The goal of this study was to develop and validate the performance of knee joint models, with anatomical and subject-specific kinematic constraints, used in MBO to reduce STA errors. Twenty subjects were recruited: 10 healthy and 10 osteoarthritis (OA) subjects. Subject-specific knee joint models were evaluated by comparing dynamic knee kinematics recorded by a motion capture system (KneeKG™) and optimized with MBO to quasi-static knee kinematics measured by a low-dose, upright, biplanar radiographic imaging system (EOS(®)). Errors due to STA ranged from 1.6° to 22.4° for knee rotations and from 0.8 mm to 14.9 mm for knee displacements in healthy and OA subjects. Subject-specific knee joint models were most effective in compensating for STA in terms of abduction-adduction, inter-external rotation and antero-posterior displacement. Root mean square errors with subject-specific knee joint models ranged from 2.2±1.2° to 6.0±3.9° for knee rotations and from 2.4±1.1 mm to 4.3±2.4 mm for knee displacements in healthy and OA subjects, respectively. Our study shows that MBO can be improved with subject-specific knee joint models, and that the quality of the motion capture calibration is critical. Future investigations should focus on more refined knee joint models to reproduce specific OA knee geometry and physiology.

  17. Which osteotomy for a valgus knee?

    PubMed Central

    Cipolla, Massimo; Cerullo, Guglielmo; Franco, Vittorio; Giannì, Enrico

    2009-01-01

    A valgus knee is a disabling condition that can affect patients of all ages. Antivalgus osteotomy of the knee is the treatment of choice to correct the valgus, to eliminate pain in the young or middle age patient, and to avoid or delay a total knee replacement. A distal femoral lateral opening wedge procedure appears to be one of the choices for medium or large corrections and is particularly easy and precise if compared to the medial femoral closing wedge osteotomy. However, if the deformity is minimal, a tibial medial closing wedge osteotomy can be done with a faster healing and a short recovery time. PMID:19547972

  18. Variant rabbit hemorrhagic disease virus in young rabbits, Spain.

    PubMed

    Dalton, Kevin P; Nicieza, Inés; Balseiro, Ana; Muguerza, María A; Rosell, Joan M; Casais, Rosa; Álvarez, Ángel L; Parra, Francisco

    2012-12-01

    Outbreaks of rabbit hemorrhagic disease have occurred recently in young rabbits on farms on the Iberian Peninsula where rabbits were previously vaccinated. Investigation identified a rabbit hemorrhagic disease virus variant genetically related to apathogenic rabbit caliciviruses. Improved antivirus strategies are needed to slow the spread of this pathogen.

  19. Data Collection and Analysis Using Wearable Sensors for Monitoring Knee Range of Motion after Total Knee Arthroplasty

    PubMed Central

    Chiang, Chih-Yen; Chen, Kun-Hui; Liu, Kai-Chun; Hsu, Steen Jun-Ping; Chan, Chia-Tai

    2017-01-01

    Total knee arthroplasty (TKA) is the most common treatment for degenerative osteoarthritis of that articulation. However, either in rehabilitation clinics or in hospital wards, the knee range of motion (ROM) can currently only be assessed using a goniometer. In order to provide continuous and objective measurements of knee ROM, we propose the use of wearable inertial sensors to record the knee ROM during the recovery progress. Digitalized and objective data can assist the surgeons to control the recovery status and flexibly adjust rehabilitation programs during the early acute inpatient stage. The more knee flexion ROM regained during the early inpatient period, the better the long-term knee recovery will be and the sooner early discharge can be achieved. The results of this work show that the proposed wearable sensor approach can provide an alternative for continuous monitoring and objective assessment of knee ROM recovery progress for TKA patients compared to the traditional goniometer measurements. PMID:28241434

  20. Cryopreservation of rabbit semen: comparing the effects of different cryoprotectants, cryoprotectant-free vitrification, and the use of albumin plus osmoprotectants on sperm survival and fertility after standard vapor freezing and vitrification.

    PubMed

    Rosato, Maria Pina; Iaffaldano, Nicolaia

    2013-02-01

    best recovery of DNA-intact sperm was recorded for BSA plus sucrose compared with semen vitrified without osmoprotectants (P < 0.05). Finally, the cryodiluent combinations BSA/sucrose and BSA/trehalose were compared in an insemination trial. Rabbit does were inseminated with fresh semen (N = 56), semen conventionally cryopreserved in the BSA-based cryodiluents containing 0.1 M sucrose or trehalose (N = 56 per group), or semen vitrified in the presence of 0.25 M sucrose or trehalose (N = 8 per group). Fertility rates and live born kids were similar for semen cryopreserved with BSA/sucrose (77% and 7.6) compared with fresh semen (84% and 8.1) and significantly higher than the figures recorded for the conventionally frozen semen in the BSA/trehalose group (52% and 6.1; P ≤ 0.05). In contrast, only one doe inseminated with semen vitrified in the presence of BSA/sucrose became pregnant, though no kids were delivered. The conclusions to be drawn from our study are: (1) incubation times and concentration toxicities established for the main permeable CPAs used for conventional freezing of rabbit sperm indicated that DMSO 10% was the least damaging; (2) CPA-free vitrification of rabbit semen led to a low or null sperm cryosurvival; and (3) enriching the freezing medium with BSA plus adequate amounts of sucrose or trehalose can improve the cryosurvival of rabbit sperm after conventional freezing or vitrification. In our working conditions, BSA/sucrose was more effective than BSA/trehalose at preserving the in vivo fertilization capacity of rabbit sperm cryopreserved using the standard procedure.

  1. Design and cadaveric validation of a novel device to quantify knee stability during total knee arthroplasty.

    PubMed

    Siston, Robert A; Maack, Thomas L; Hutter, Erin E; Beal, Matthew D; Chaudhari, Ajit M W

    2012-11-01

    The success of total knee arthroplasty depends, in part, on the ability of the surgeon to properly manage the soft tissues surrounding the joint, but an objective definition as to what constitutes acceptable postoperative joint stability does not exist. Such a definition may not exist due to lack of suitable instrumentation, as joint stability is currently assessed by visual inspection while the surgeon manipulates the joint. Having the ability to accurately and precisely measure knee stability at the time of surgery represents a key requirement in the process of objectively defining acceptable joint stability. Therefore, we created a novel sterilizable device to allow surgeons to measure varus-valgus, internal-external, or anterior-posterior stability of the knee during a total knee arthroplasty. The device can be quickly adjusted between 0 deg and 90 deg of knee flexion. The device interfaces with a custom surgical navigation system, which records the resultant rotations or translations of the knee while the surgeon applies known loads to a patient's limb with a handle instrumented with a load cell. We validated the performance of the device by having volunteers use it to apply loads to a mechanical linkage that simulated a knee joint; we then compared the joint moments calculated by our stability device against those recorded by a load cell in the simulated knee joint. Validation of the device showed low mean errors (less than 0.21 ± 1.38 Nm and 0.98 ± 3.93 N) and low RMS errors (less than 1.5 Nm and 5 N). Preliminary studies from total knee arthroplasties performed on ten cadaveric specimens also demonstrate the utility of our new device. Eventually, the use of this device may help determine how intra-operative knee stability relates to postoperative function and could lead to an objective definition of knee stability and more efficacious surgical techniques.

  2. Adipose derived mesenchymal stem cell therapy in the treatment of isolated knee chondral lesions: design of a randomised controlled pilot study comparing arthroscopic microfracture versus arthroscopic microfracture combined with postoperative mesenchymal stem cell injections

    PubMed Central

    Freitag, Julien; Ford, Jon; Bates, Dan; Boyd, Richard; Hahne, Andrew; Wang, Yuanyuan; Cicuttini, Flavia; Huguenin, Leesa; Norsworthy, Cameron; Shah, Kiran

    2015-01-01

    Introduction The management of intra-articular chondral defects in the knee remains a challenge. Inadequate healing in areas of weight bearing leads to impairment in load transmission and these defects predispose to later development of osteoarthritis. Surgical management of full thickness chondral defects include arthroscopic microfracture and when appropriate autologous chondrocyte implantation. This latter method however is technically challenging, and may not offer significant improvement over microfracture. Preclinical and limited clinical trials have indicated the capacity of mesenchymal stem cells to influence chondral repair. The aim of this paper is to describe the methodology of a pilot randomised controlled trial comparing arthroscopic microfracture alone for isolated knee chondral defects versus arthroscopic microfracture combined with postoperative autologous adipose derived mesenchymal stem cell injections. Methods and analysis A pilot single-centre randomised controlled trial is proposed. 40 participants aged 18–50 years, with isolated femoral condyle chondral defects and awaiting planned arthroscopic microfracture will be randomly allocated to a control group (receiving no additional treatment) or treatment group (receiving postoperative adipose derived mesenchymal stem cell treatment). Primary outcome measures will include MRI assessment of cartilage volume and defects and the Knee Injury and Osteoarthritis Outcome Score. Secondary outcomes will include further MRI assessment of bone marrow lesions, bone area and T2 cartilage mapping, a 0–10 Numerical Pain Rating Scale, a Global Impression of Change score and a treatment satisfaction scale. Adverse events and cointerventions will be recorded. Initial outcome follow-up for publication of results will be at 12 months. Further annual follow-up to assess long-term differences between the two group will occur. Ethics and dissemination This trial has received prospective ethics approval through

  3. A Novel Method of Evaluating Knee Joint Stability of Patients with Knee Osteoarthritis: Multiscale Entropy Analysis with A Knee-Aiming Task.

    PubMed

    Zhou, Diange; Zhang, Shijie; Zhang, Hui; Jiang, Long; Zhang, Jue; Fang, Jing

    2017-03-23

    Deteriorating knee stability is a local risk factor that reflects the occurrence and aggregative of osteoarthritis (OA). Despite the many biomechanics-based methods for assessing the structural stability of knee joints in clinics, these methods have many limitations. The stability of the knee joint relies on not only biomechanical factors, but also proprioception and the central nervous system. In this study, we attempt to depict the stability of knee joint from a holistic viewpoint, and a novel index of knee joint stability (IKJS) was thus extracted. We compared the differences of IKJS in 57 healthy volunteers and 55 patients with OA before and after total knee replacement (TKR). Analysis of Variance results demonstrated that there existed significant differences in IKJS among the three participating groups (<0.0001). Also, the IKJS of the operated leg in patients with knee OA increased remarkably after TKR (p < 0.0001). Furthermore, the results of the experiment suggested that the IKJS has sufficient reproducibility (ICC = 0.80). In conclusion, the proposed IKJS that employs the knee-aiming task is feasible for quantitatively determining knee stability. It can provide a potentially valuable and convenient tool to evaluate the effect of postoperative rehabilitation for patients with knee OA.

  4. Intraoperative knee anthropometrics: correlation with cartilage wear.

    PubMed

    Rooney, N; Fitzpatrick, D P; Beverland, D E

    2006-08-01

    Accurate knee morphology is of value in determining the correct sizing of prosthetic implants. Intraoperative measurement of key linear dimensional variables was carried out on 196 Caucasian knees (osteoarthritic patients: 68 male and 128 female). Of the 196 knees measured, 70 had extensive cartilage degeneration. Statistical analysis was carried out on this large sample size of data. Summary statistics and correlation coefficients between variables were determined and compared between subgroups. Male knees were on average larger than female knees. Higher correlation was found between variables for males than between variables for females. Overall, the patellar dimensions were seen to correlate least well with other anatomical variables. High correlation between femoral variables supports current femoral sizing procedure, although routine patellar resection practices are called into question. Average values for the 70 knees with extensive cartilage degeneration were significantly smaller (P < 0.01) than their counterparts for the other 126 knees. For a measurement not containing cartilage, such as femoral epicondylar width, this difference cannot be accounted for by the loss of cartilage owing to wear. This suggests that, for similar height and weight, a naturally narrower femoral epicondylar width may be associated with severe osteoarthritis.

  5. Knee extension torque variability after exercise in ACL reconstructed knees.

    PubMed

    Goetschius, John; Kuenze, Christopher M; Hart, Joseph M

    2015-08-01

    The purpose of this study was to compare knee extension torque variability in patients with ACL reconstructed knees before and after exercise. Thirty two patients with an ACL reconstructed knee (ACL-R group) and 32 healthy controls (control group) completed measures of maximal isometric knee extension torque (90° flexion) at baseline and following a 30-min exercise protocol (post-exercise). Exercise included 30-min of repeated cycles of inclined treadmill walking and hopping tasks. Dependent variables were the coefficient of variation (CV) and raw-change in CV (ΔCV): CV = (torque standard deviation/torque mean x 100), ΔCV = (post-exercise - baseline). There was a group-by-time interaction (p = 0.03) on CV. The ACL-R group demonstrated greater CV than the control group at baseline (ACL-R = 1.07 ± 0.55, control = 0.79 ± 0.42, p = 0.03) and post-exercise (ACL-R = 1.60 ± 0.91, control = 0.94 ± 0.41, p = 0.001). ΔCV was greater (p = 0.03) in the ACL-R group (0.52 ± 0.82) than control group (0.15 ± 0.46). CV significantly increased from baseline to post-exercise (p = 0.001) in the ACL-R group, while the control group did not (p = 0.06). The ACL-R group demonstrated greater knee extension torque variability than the control group. Exercise increased torque variability more in the ACL-R group than control group.

  6. Knee extension and flexion: MR delineation of normal and torn anterior cruciate ligaments

    SciTech Connect

    Niitsu, Mamoru; Ikeda, Kotaroh; Fukubayashi, Tohru; Anno, Izumi; Itai, Yuji

    1996-03-01

    Our goal was to assess the effect of joint position of semiflexed and extended knees in MR delineation of the anterior cruciate ligament (ACL). With a mobile knee brace and a flexible surface coil, the knee joint was either fully extended or bent to a semiflexed position (average 45{degrees} of flexion) within the magnet bore. Sets of oblique sagittal MR images were obtained for both extended and flexed knee positions. Thirty-two knees with intact ACLs and 43 knees with arthroscopically proven ACL tears were evaluated. Two observers compared paired MR images of both extended and flexed positions and rated them by a relative three point scale. Anatomic correlation in MR images was obtained by a cadaveric knee with incremental flexion. The MR images of flexed knees were more useful than of extended knees in 53% of the case reviews of femoral attachments and 36% of reviews of midportions of normal ACLs. Compared with knee extensions, the MR images for knee flexion provided better clarity in 48% of reviews of disrupted sites and 52% of residual bundles of torn ACLs. Normal ACL appeared taut in the knee extension and lax in semiflexion. Compared with MR images of knees in extension, MR images of knees in flexion more clearly delineate the femoral side of the ligament with wider space under the intercondylar roof and with decreased volume-averaging artifacts, providing superior visualization of normal and torn ACLs. 13 refs., 7 figs., 1 tab.

  7. Repair of experimentally produced defects in rabbit articular cartilage by autologous chondrocyte transplantation

    SciTech Connect

    Grande, D.A.; Pitman, M.I.; Peterson, L.; Menche, D.; Klein, M.

    1989-01-01

    Using the knee joints of New Zealand White rabbits, a baseline study was made to determine the intrinsic capability of cartilage for healing defects that do not fracture the subchondral plate. A second experiment examined the effect of autologous chondrocytes grown in vitro on the healing rate of these defects. To determine whether any of the reconstituted cartilage resulted from the chondrocyte graft, a third experiment was conducted involving grafts with chondrocytes that had been labeled prior to grafting with a nuclear tracer. Results were evaluated using both qualitative and quantitative light microscopy. Macroscopic results from grafted specimens displayed a marked decrease in synovitis and other degenerative changes. In defects that had received transplants, a significant amount of cartilage was reconstituted (82%) compared to ungrafted controls (18%). Autoradiography on reconstituted cartilage showed that there were labeled cells incorporated into the repair matrix.

  8. Unicompartmental knee prosthesis implantation with a non-image-based navigation system: rationale, technique, case-control comparative study with a conventional instrumented implantation.

    PubMed

    Jenny, Jean-Yves; Boeri, Cyril

    2003-01-01

    The accuracy of implantation is an accepted prognostic factor for the long-term survival of unicompartmental knee prostheses (UKP). We developed a non-image-guided navigation system for UKP implantation without any extramedullary or intramedullary guiding device. The 30 patients operated on with the navigation system (group A) were matched to 30 patients operated on with the conventional technique (group B) using age, sex, body mass index, preoperative coronal mechanical femorotibial angle, and severity of the preoperative degenerative changes. All patients had a complete radiological examination in the first 3 months after the index procedure, with anteroposterior and lateral plain knee radiographs and anteroposterior and lateral long leg radiographs. Coronal femorotibial mechanical angle and both coronal and sagittal orientations of the femoral and tibial components were measured. There were no significant differences in the mean numerical values of all measured angles except for the sagittal orientation of the tibial component, with a significant excessive posterior tibial slope in group B. There was a significant increase in the rate of prostheses implanted in the desired angular range for all criteria except the coronal mechanical femorotibial angle in group A. An optimal implantation with all optimal items was obtained by 18 cases in group A and 6 cases in group B. Navigated implantation of a UKP with the used, non-image-based system improved the accuracy of the radiological implantation without any significant inconvenience and with little change in the conventional operative technique. The only inconvenience was a 20-min longer operative time. This improvement could be related to a longer survival of such implanted prostheses.

  9. A comparative study of changes operated by sympathetic nervous system activation on spindle afferent discharge and on tonic vibration reflex in rabbit jaw muscles.

    PubMed

    Passatore, M; Deriu, F; Grassi, C; Roatta, S

    1996-03-07

    The effect of sympathetic activation on the spindle afferent response to vibratory stimuli eliciting the tonic vibration reflex in jaw closing muscles was studied in precollicularly decerebrate rabbits. Stimulation of the cervical sympathetic trunk, at frequencies within the physiologic range, consistently induced a decrease in spindle response to muscle vibration, which was often preceded by a transient enhancement. Spindle discharge was usually correlated with the EMG activity in the masseter muscle and the tension reflexly developed by jaw muscles. The changes in spindle response to vibration were superimposed on variations of the basal discharge which exhibited different patterns in the studied units, increases in the firing rate being more frequently observed. These effects were mimicked by close arterial injection of the selective alpha 1-adrenoceptor agonist phenylephrine. Data presented here suggest that sympathetically-induced modifications of the tonic vibration reflex are due to changes exerted on muscle spindle afferent information.

  10. INFECTIOUS PAPILLOMATOSIS OF RABBITS

    PubMed Central

    Shope, Richard E.; Hurst, E. Weston

    1933-01-01

    A papilloma has been observed in wild cottontail rabbits and has been found to be transmissible to both wild and domestic rabbits. The clinical and pathological pictures of the condition have been described. It has been found that the causative agent is readily filtrable through Berkefeld but not regularly through Seitz filters, that it stores well in glycerol, that it is still active after heating to 67°C. for 30 minutes, but not after heating to 70°C., and that it exhibits a marked tropism for cutaneous epithelium. The activities and properties of the papilloma-producing agent warrant its classification as a filtrable virus. Rabbits carrying experimentally produced papillomata are partially or completely immune to reinfection and, furthermore, their sera partially or completely neutralize the causative virus. The disease is transmissible in series through wild rabbits and virus of wild rabbit origin is readily transmissible to domestic rabbits, producing in this species papillomata identical in appearance with those found in wild rabbits. However, the condition is not transmissible in series through domestic rabbits. The possible significance of this observation has been discussed. The virus of infectious papillomatosis is not related immunologically to either the virus of infectious fibroma or to that of infectious myxoma of rabbits. PMID:19870219

  11. Urethral healing in rabbits.

    PubMed

    Scherz, H C; Kaplan, G W; Boychuk, D I; Landa, H M; Haghighi, P

    1992-08-01

    We studied urethral healing in New Zealand white rabbits by histological examination after insult (urethral catheter) or injury (urethrotomy) specifically for acute and chronic inflammation, fibrosis, fistulas, squamous metaplasia, foreign body giant cells and urethral dilatation. Urethral catheterization resulted in increased inflammation and fibrosis compared to noncatheterized animals. Skin closure techniques and materials resulted in an inflammatory response that may extend to and involve the urethra. Minor differences in suture size were not an important variable but the persistence of suture material may have a role in the degree of inflammation and the formation of foreign body giant cells. Transepithelial closure techniques drag epithelial cells into subcutaneous tissues and may predispose to fistula formation.

  12. The contribution of leg press and knee extension strength and power to physical function in people with knee osteoarthritis: A cross-sectional study.

    PubMed

    Tevald, Michael A; Murray, Amanda M; Luc, Brittney; Lai, Kafai; Sohn, David; Pietrosimone, Brian

    2016-12-01

    The purposes of this study were to 1) determine the additional contributions of leg press and knee extensor power, over and above that of strength, to the performance of physical function tasks in people with knee osteoarthritis, and 2) compare the ability of bilateral leg press to unilateral knee extensor strength and power to predict functional task performance.

  13. Jumper's Knee (Patellar Tendonitis)

    MedlinePlus

    ... regularly play sports that involve a lot of repetitive jumping — like track and field (particularly high-jumping), basketball, volleyball, gymnastics, running, and soccer — can put a lot of strain on their knees. Jumper's knee can seem like a minor injury that isn't really that serious. Because of ...

  14. Tuberculosis of the knee

    PubMed Central

    Lidder, Surjit; Lang, Kathryn; Haroon, Mallick; Shahidi, Mitra; El-Guindi, Magdi

    2009-01-01

    Extrapulmonary manifestations of tuberculosis are reported in less than one in five cases with the knee affected in 8% after the spine and hip. We report a case of isolated highly erosive tuberculosis of the knee presenting in a previously fit Vietnamese woman. The difficulties of diagnosis, modalities of chemotherapeutic management, and surgical treatment are discussed. PMID:21808686

  15. Partial knee replacement

    MedlinePlus

    ... American Academy of Orthopedic Surgeons (AAOS). Treatment of osteoarthritis of the knee: Evidence-based guideline 2nd edition (summary). Rosemont, IL. ... al. American Academy of Orthopaedic Surgeons. Treatment of osteoarthritis of the knee (nonarthroplasty). J Am Acad Orthop Surg . 2009;17: ...

  16. Pneumatic osteoarthritis knee brace.

    PubMed

    Stamenović, Dimitrije; Kojić, Milos; Stojanović, Boban; Hunter, David

    2009-04-01

    Knee osteoarthritis is a chronic disease that necessitates long term therapeutic intervention. Biomechanical studies have demonstrated an improvement in the external adduction moment with application of a valgus knee brace. Despite being both efficacious and safe, due to their rigid frame and bulkiness, current designs of knee braces create discomfort and difficulties to patients during prolonged periods of application. Here we propose a novel design of a light osteoarthritis knee brace, which is made of soft conforming materials. Our design relies on a pneumatic leverage system, which, when pressurized, reduces the excessive loads predominantly affecting the medial compartment of the knee and eventually reverses the malalignment. Using a finite-element analysis, we show that with a moderate level of applied pressure, this pneumatic brace can, in theory, counterbalance a greater fraction of external adduction moment than the currently existing braces.

  17. Impact of a novel, antimicrobial dressing on in vivo, Pseudomonas aeruginosa wound biofilm: quantitative comparative analysis using a rabbit ear model.

    PubMed

    Seth, Akhil K; Zhong, Aimei; Nguyen, Khang T; Hong, Seok J; Leung, Kai P; Galiano, Robert D; Mustoe, Thomas A

    2014-01-01

    The importance of bacterial biofilms to chronic wound pathogenesis is well established. Different treatment modalities, including topical dressings, have yet to show consistent efficacy against wound biofilm. This study evaluates the impact of a novel, antimicrobial Test Dressing on Pseudomonas aeruginosa biofilm-infected wounds. Six-mm dermal punch wounds in rabbit ears were inoculated with 10(6) colony-forming units of P. aeruginosa. Biofilm was established in vivo using our published model. Dressing changes were performed every other day with either Active Control or Test Dressings. Treated and untreated wounds were harvested for several quantitative endpoints. Confirmatory studies were performed to measure treatment impact on in vitro P. aeruginosa and in vivo polybacterial wounds containing P. aeruginosa and Staphylococcus aureus. The Test Dressing consistently decreased P. aeruginosa bacterial counts, and improved wound healing relative to Inactive Vehicle and Active Control wounds (p < 0.05). In vitro bacterial counts were also significantly reduced following Test Dressing therapy (p < 0.05). Similarly, improvements in bacterial burden and wound healing were also achieved in polybacterial wounds (p < 0.05). This study represents the first quantifiable and consistent in vivo evidence of a topical antimicrobial dressing's impact against established wound biofilm. The development of clinically applicable therapies against biofilm such as this is critical to improving chronic wound care.

  18. Autoantibody Production in Rabbits

    PubMed Central

    Asherson, G. L.; Rose, M. Elaine

    1963-01-01

    The finding that the serum of apparently healthy rabbits fixed complement with rabbit liver and kidney has been confirmed. Experimental infection of rabbits with Eimeria stiedae, the cause of hepatic coccidiosis, led to a rise in the titre of serum complement-fixing factors. The rise was statistically significant 14, 21 and 28 days after infection. The factors were regarded as antibodies because they behaved as macroglobulins on diethylaminoethyl—cellulose chromatography and sucrose gradient centrifugation, and as autoantibodies because they fixed complement with the kidney of the rabbits in which they occurred. The antibody reacted with widely distributed antigen(s) with high activity in brain and low activity in skeletal muscle. The possibility that coccidial infection may be responsible for the natural autoantibody of rabbits is discussed. PMID:13965167

  19. Evaluation of total knee mechanics using a crouching simulator with a synthetic knee substitute.

    PubMed

    Lowry, Michael; Rosenbaum, Heather; Walker, Peter S

    2016-05-01

    Mechanical evaluation of total knees is frequently required for aspects such as wear, strength, kinematics, contact areas, and force transmission. In order to carry out such tests, we developed a crouching simulator, based on the Oxford-type machine, with novel features including a synthetic knee including ligaments. The instrumentation and data processing methods enabled the determination of contact area locations and interface forces and moments, for a full flexion-extension cycle. To demonstrate the use of the simulator, we carried out a comparison of two different total knee designs, cruciate retaining and substituting. The first part of the study describes the simulator design and the methodology for testing the knees without requiring cadaveric knee specimens. The degrees of freedom of the anatomic hip and ankle joints were reproduced. Flexion-extension was obtained by changing quadriceps length, while variable hamstring forces were applied using springs. The knee joint was represented by three-dimensional printed blocks on to which the total knee components were fixed. Pretensioned elastomeric bands of realistic stiffnesses passed through holes in the block at anatomical locations to represent ligaments. Motion capture of the knees during flexion, together with laser scanning and computer modeling, was used to reconstruct contact areas on the bearing surfaces. A method was also developed for measuring tibial component interface forces and moments as a comparative assessment of fixation. The method involved interposing Tekscan pads at locations on the interface. Overall, the crouching machine and the methodology could be used for many different mechanical measurements of total knee designs, adapted especially for comparative or parametric studies.

  20. A multicentre, pragmatic, parallel group, randomised controlled trial to compare the clinical and cost-effectiveness of three physiotherapy-led exercise interventions for knee osteoarthritis in older adults: the BEEP trial protocol (ISRCTN: 93634563)

    PubMed Central

    2014-01-01

    Background Exercise is consistently recommended for older adults with knee pain related to osteoarthritis. However, the effects from exercise are typically small and short-term, likely linked to insufficient individualisation of the exercise programme and limited attention to supporting exercise adherence over time. The BEEP randomised trial aims to improve patients’ short and long-term outcomes from exercise. It will test the overall effectiveness and cost-effectiveness of two physiotherapy-led exercise interventions (Individually Tailored Exercise and Targeted Exercise Adherence) to improve the individual tailoring of, and adherence to exercise, compared with usual physiotherapy care. Methods/design Based on the learning from a pilot study (ISRCTN 23294263), the BEEP trial is a multi-centre, pragmatic, parallel group, individually randomised controlled trial, with embedded longitudinal qualitative interviews. 500 adults in primary care, aged 45 years and over with knee pain will be randomised to 1 of 3 treatment groups delivered by fully trained physiotherapists in up to 6 NHS services. These are: Usual Physiotherapy Care (control group consisting of up to 4 treatment sessions of advice and exercise), Individually Tailored Exercise (an individualised, supervised and progressed lower-limb exercise programme) or Targeted Exercise Adherence (supporting patients to adhere to exercise and to engage in general physical activity over the longer-term). The primary outcomes are pain and function as measured by the Western Ontario and McMaster Osteoarthritis index. A comprehensive range of secondary outcomes are also included. Outcomes are measured at 3, 6 (primary outcome time-point), 9, 18 and 36 months. Data on adverse events will also be collected. Semi-structured, qualitative interviews with a subsample of 30 participants (10 from each treatment group) will be undertaken at two time-points (end of treatment and 12 to 18 months later) and analysed thematically

  1. Leukocyte and Platelet Rich Plasma (L-PRP) Versus Leukocyte and Platelet Rich Fibrin (L-PRF) For Articular Cartilage Repair of the Knee: A Comparative Evaluation in an Animal Model

    PubMed Central

    Kazemi, Davoud; Fakhrjou, Ashraf

    2015-01-01

    Background: Articular cartilage injuries of the knee are among the most debilitating injuries leading to osteoarthritis due to limited regenerative capability of cartilaginous tissue. The use of platelet concentrates containing necessary growth factors for cartilage healing has recently emerged as a new treatment method. Objectives: The efficacy of two types of different platelet concentrates were compared in the treatment of acute articular cartilage injuries of the knee in an animal model. Materials and Methods: Eighteen adult Iranian mixed breed male dogs were used to conduct this experimental study. Full thickness articular cartilage defects (diameter 6 mm, depth 5 mm) were created in the weight bearing area of femoral condyles of both hind limbs in all dogs (n = 72). Twelve dogs were randomly selected to receive treatment and their right and left hind limb defects were treated by L-PRP and L-PRF implantation respectively, while no treatment was undertaken in six other dogs as controls. The animals were euthanized at 4, 16 and 24 weeks following surgery and the resultant repair tissue was investigated macroscopically and microscopically. At each sampling time, 4 treated dogs and 2 control dogs were euthanized, therefore 8 defects per group were evaluated. Results: Mean macroscopic scores of the treated defects were higher than the controls at all sampling times with significant differences (P < 0.05) observed between L-PRF treated and control defects (10.13 vs. 8.37) and L-PRP treated and control defects (10 vs. 8.5) at 4 and 16 weeks, respectively. A similar trend in mean total microscopic scores was observed with a significant difference (P < 0.05) between L-PRP treated and control defects at 4 (9.87 vs. 7.62) and 16 (13.38 vs. 11) weeks. No significant difference was observed between the platelet concentrate treated defects in either mean macroscopic scores or mean total microscopic scores. Conclusions: Both L-PRP and L-PRF could be used to effectively

  2. Allogeneic Mesenchymal Stem Cells in Combination with Hyaluronic Acid for the Treatment of Osteoarthritis in Rabbits.

    PubMed

    Chiang, En-Rung; Ma, Hsiao-Li; Wang, Jung-Pan; Liu, Chien-Lin; Chen, Tain-Hsiung; Hung, Shih-Chieh

    2016-01-01

    Mesenchymal stem cell (MSC)-based therapies may aid in the repair of articular cartilage defects. The purpose of this study was to investigate the effects of intraarticular injection of allogeneic MSCs in an in vivo anterior cruciate ligament transection (ACLT) model of osteoarthritis in rabbits. Allogeneic bone marrow-derived MSCs were isolated and cultured under hypoxia (1% O2). After 8 weeks following ACLT, MSCs suspended in hyaluronic acid (HA) were injected into the knees, and the contralateral knees were injected with HA alone. Additional controls consisted of a sham operation group as well as an untreated osteoarthritis group. The tissues were analyzed by macroscopic examination as well as histologic and immunohistochemical methods at 6 and 12 weeks post-transplantation. At 6 and 12 weeks, the joint surface showed less cartilage loss and surface abrasion after MSC injection as compared to the tissues receiving HA injection alone. Significantly better histological scores and cartilage content were observed with the MSC transplantation. Furthermore, engraftment of allogenic MSCs were evident in surface cartilage. Thus, injection of the allogeneic MSCs reduced the progression of osteoarthritis in vivo.

  3. The influence of body mass index and velocity on knee biomechanics during walking.

    PubMed

    Freedman Silvernail, Julia; Milner, Clare E; Thompson, Dixie; Zhang, Songning; Zhao, Xiaopeng

    2013-04-01

    Obesity has been associated with both the development and progression of knee osteoarthritis. Being overweight or obese from a young age is likely to decrease the age of onset for co-morbidities of obesity such as osteoarthritis. However, research on osteoarthritis has thus far focused on older adults. Therefore, the purpose of this study was to determine whether young adults who are overweight or obese exhibit biomechanical risk factors for knee osteoarthritis at either their preferred walking velocity or at 1m/s, which was slower than the preferred velocity. Thirty healthy young adults formed three equal groups according to body mass index. Three dimensional kinetics and kinematics were collected while participants walked overground at both velocities. Joint moments were normalized to fat free weight and height. The preferred walking velocity of obese participants was slower than that of normal weight individuals. There were no differences in knee flexion excursion, peak knee flexion angle, normalized peak knee flexion moment or normalized peak knee adduction moment among groups. Obese participants walked with lower peak knee adduction angle than both overweight and normal body mass index participants and several shifted towards knee abduction. All groups had smaller knee flexion excursion, peak knee flexion angle, peak knee flexion moment and peak knee adduction moment at 1m/s compared to preferred walking velocity. Overall, young and otherwise healthy overweight and obese participants have knee biomechanics during gait at preferred and slow walking velocities that are comparable to normal weight adults.

  4. Knee kinetic pattern during gait and anterior knee pain before and after rehabilitation in patients with patellofemoral pain syndrome.

    PubMed

    Claudon, B; Poussel, M; Billon-Grumillier, C; Beyaert, C; Paysant, J

    2012-05-01

    Patellofemoral pain is likely due to compressive force acting on the patella related in turn to knee extension moment. The latter variable was assumed to be (i) reduced during short-distance free walking in case of patellofemoral pain syndrome and (ii) increased after therapeutic pain reduction. Peak knee extension moment at beginning of stance phase was recorded by three-dimensional gait analysis in 22 controls and in 23 patients with patellofemoral pain syndrome before and after rehabilitation of knee extensors and flexors to reduce the pain. Pain would occur mainly in stressful activities such as stair negotiation or squatting and was quantified by the anterior knee pain scale. Peak knee extension moment was significantly reduced in all the patients before treatment (n=23) compared to controls, although no one had pain during free walking. In the 17 patients who experienced significant post-rehabilitation pain reduction in their stressful activities, the peak knee extension moment was significantly reduced before treatment compared to controls and significantly increased after treatment, reaching values similar to control values. The peak knee extension moment during free walking appears to be a good kinetic variable related to a compensatory mechanism limiting or avoiding anterior knee pain and may be of interest in assessing knee dynamics alteration in patients with PFPS.

  5. Advanced concepts in knee arthrodesis

    PubMed Central

    Wood, Jennifer H; Conway, Janet D

    2015-01-01

    The aim is to describe advanced strategies that can be used to diagnose and treat complications after knee arthrodesis and to describe temporary knee arthrodesis to treat infected knee arthroplasty. Potential difficult complications include nonunited knee arthrodesis, limb length discrepancy after knee arthrodesis, and united but infected knee arthrodesis. If a nonunited knee arthrodesis shows evidence of implant loosening or failure, then bone grafting the nonunion site as well as exchange intramedullary nailing and/or supplemental plate fixation are recommended. If symptomatic limb length discrepancy cannot be satisfactorily treated with a shoe lift, then the patient should undergo tibial lengthening over nail with a monolateral fixator or exchange nailing with a femoral internal lengthening device. If a united knee arthrodesis is infected, the nail must be removed. Then the surgeon has the option of replacing it with a long, antibiotic cement-coated nail. The authors also describe temporary knee arthrodesis for infected knee arthroplasty in patients who have the potential to undergo insertion of a new implant. The procedure has two goals: eradication of infection and stabilization of the knee. A temporary knee fusion can be accomplished by inserting both an antibiotic cement-coated knee fusion nail and a static antibiotic cement-coated spacer. These advanced techniques can be helpful when treating difficult complications after knee arthrodesis and treating cases of infected knee arthroplasty. PMID:25793160

  6. Robotic control in knee joint replacement surgery.

    PubMed

    Davies, B L; Rodriguez y Baena, F M; Barrett, A R W; Gomes, M P S F; Harris, S J; Jakopec, M; Cobb, J P

    2007-01-01

    A brief history of robotic systems in knee arthroplasty is provided. The place of autonomous robots is then discussed and compared to more recent 'hands-on' robotic systems that can be more cost effective. The case is made for robotic systems to have a clear justification, with improved benefits compared to those from cheaper navigation systems. A number of more recent, smaller, robot systems for knee arthroplasty are also described. A specific example is given of an active constraint medical robot, the ACROBOT system, used in a prospective randomized controlled trial of unicondylar robotic knee arthroplasty in which the robot was compared to conventional surgery. The results of the trial are presented together with a discussion of the need for measures of accuracy to be introduced so that the efficacy of the robotic surgery can be immediately identified, rather than have to wait for a number of years before long-term clinical improvements can be demonstrated.

  7. Pathological Knee Joint Motion Analysis By High Speed Cinephotography

    NASA Astrophysics Data System (ADS)

    Baumann, Jurg U.

    1985-02-01

    The use of cinephotography for evaluation of disturbed knee joint function was compared in three groups of patients. While a sampling rate of 50 images per second was adequate for patients with neuromuscular disorders, a higher frequency of around 300 i.p.s. is necessary in osteoarthritis and ligamentous knee joint injuries, but the task of digitizing is prohibitive unless automated.

  8. SPF rabbits infected with rabbit hepatitis E virus isolate experimentally showing the chronicity of hepatitis.

    PubMed

    Han, Jian; Lei, Yaxin; Liu, Lin; Liu, Peng; Xia, Junke; Zhang, Yulin; Zeng, Hang; Wang, Lin; Wang, Ling; Zhuang, Hui

    2014-01-01

    This study focused on investigating the pathogenesis seen in specific-pathogen-free (SPF) rabbits following infection with a homologous rabbit HEV isolate (CHN-BJ-rb14) and comparing it to that seen following infection with a heterologous swine genotype 4 HEV isolate (CHN-XJ-SW13). Three of the four animals inoculated with the homologous rabbit HEV became infected, exhibiting an intermittent viremia, obvious fluctuations of liver function biomarkers alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and persistent fecal virus shedding throughout the nine month study. In addition, liver histopathology showed both chronic inflammation and some degree of fibrosis. Both positive and negative-stranded HEV RNA and HEV antigen expression were detected in liver, brain, stomach, duodenum and kidney from the necropsied rabbits. Inflammation of extrahepatic tissue (duodenum and kidney) was also observed. Three of the four rabbits inoculated with the heterologous genotype 4 swine HEV also became infected, showing similar levels of anti-HEV antibody to that generated following infection with the homologous virus isolate. The duration of both viremia and fecal shedding of virus was however shorter following infection with the heterologous virus and there was no significant elevation of liver function biomarkers. These results suggest that rabbit HEV infection may cause more severe hepatitis and prolong the course of the disease, with a possible chronic trend of hepatitis in SPF rabbits.

  9. Hepatitis E Virus in Farmed Rabbits, Wild Rabbits and Petting Farm Rabbits in the Netherlands.

    PubMed

    Burt, Sara A; Veltman, Jorg; Hakze-van der Honing, Renate; Schmitt, Heike; van der Poel, Wim H M

    2016-09-01

    Rabbits have been suggested as a zoonotic source of Hepatitis E virus. Phylogenetic analysis of HEV isolates from farmed, wild and pet rabbits in the Netherlands (23, 0, and 60 % respectively) showed them to be grouped amongst published rabbit HEV sequences and distinct from most human isolates. Dutch rabbits are unlikely to be a zoonotic source.

  10. SERUM SICKNESS IN RABBITS

    PubMed Central

    Fleisher, Mover S.; Jones, Lloyd

    1931-01-01

    1. The injection of a single large dose of normal horse serum into rabbits results in the appearance 3 to 8 days later of erythematous and edematous reactions on the ears in 68.9 per cent of the animals. 2. The injections may be given by any of several routes and reactions appear when the site of injection is definitely distant from the ears. 3. Injections of various antisera into rabbits cause the appearance of similar reactions. 4. These reactions can be considered as manifestations of serum sickness in rabbits. PMID:19869943

  11. Rabbit orthopedic surgery.

    PubMed

    Rich, Gregory A

    2002-01-01

    Orthopedic surgery in rabbits poses several unique parameters for the veterinary surgeon. It is imperative for the veterinarian to be knowledgeable about the anatomic features of the surgical repair site and to become familiar with a rabbit's pain and discomfort often associated with orthopedic injuries. Handling the perioperative and postoperative pain and potential GI disturbances are crucial for a successful outcome of the surgical case. This article is designed to help the veterinary surgeon prepare for the orthopedic surgical procedure and the peripheral physiologic needs of the rabbit from presentation through recovery.

  12. Parathyroid Hormone-Induced Bone Marrow Mesenchymal Stem Cell Chondrogenic Differentiation and its Repair of Articular Cartilage Injury in Rabbits

    PubMed Central

    Chen, Yushu; Chen, Yi; Zhang, Shujiang; Du, Xiufan; Bai, Bo

    2016-01-01

    Background We explored the effect of parathyroid hormone (PTH)-induced bone marrow stem cells (BMSCs) complexed with fibrin glue (FG) in the repair of articular cartilage injury in rabbits. Material/Methods Forty-eight rabbits randomized into four groups were subjected to articular surgery (cartilage loss). The PTH and non-PTH intervention groups included transplantation with PTH/BMSC/FG xenogeneic and BMSC/FG xenogeneic complexes, respectively, into the injured area. The injured group contained no transplant while the control group comprised rabbits without any articular injury. Samples were monitored for cartilage repair up to three months post-surgery. Immunohistochemistry as well as real-time fluorescent quantitative PCR and Western blot were used to analyze the expression of type II collagen and aggrecan in the repaired tissue. Results At 12 weeks post-surgery, the loss of articular cartilage in the PTH group was fully repaired by hyaline tissue. Typical cartilage lacunae and intact subchondral bone were found. The boundary separating the surrounding normal cartilage tissue disappeared. The gross and International Cartilage Repair Society (ICRS) histological ranking of the repaired tissue was significantly higher in the PTH intervention group than in the non-PTH intervention and injury groups (p<0.05) without any significant difference compared to the control group (p>0.05). Type II collagen and aggrecan stained positive and the average optical density, relative mRNA expression and protein-integrated optical density in the PTH group were higher than in non-PTH and injured groups (p<0.05) but not significantly different from the control group (p>0.05). Conclusions PTH/BMSC/FG xenogeneic complexes effectively repaired the loss of cartilage in rabbit knee injury. PMID:27847384

  13. Knee Conditioning Program

    MedlinePlus

    ... muscles help your knee joint absorb shock. Flexibility: Stretching the muscles that you strengthen is important for restoring range of motion and preventing injury. Gently stretching after strengthening exercises can help reduce muscle soreness ...

  14. Anterior knee pain

    MedlinePlus

    ... places extra stress on the kneecap (such as running, jumping or twisting, skiing, or playing soccer). You ... noticeable with: Deep knee bends Going down stairs Running downhill Standing up after sitting for awhile

  15. Prosthetic Knee Systems

    MedlinePlus

    ... must give support when people stand, allow smooth motion when people walk, and permit movement when people ... of knees and their options for stability and motion control would work best for them. There are ...

  16. Knee microfracture surgery

    MedlinePlus

    ... WM, Griesser MJ, Parker RD. Patellofemoral pain. In: Miller MD, Thompson SR, eds. DeLee and Drez's Orthopaedic ... ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 105. Miller RH, Azar FM. Knee injuries. In: Canale ST, ...

  17. Runners knee (image)

    MedlinePlus

    ... forces on the knee, such as a misaligned patella. Chondromalacia is treated with rest or immobilization and nonsteroidal anti-inflammatory drugs for pain. Physical therapy, especially ... alignment of the patella that cannot be corrected with therapy.

  18. Validation of a protocol to compare the effectiveness of experimental decontaminants with both components of the M258A1 kit against percutaneous application of undiluted vesicant chemical surety material to the laboratory albino rabbit. Final report, 1 March 1985-24 July 1987

    SciTech Connect

    Joiner, R.L.

    1987-07-24

    A rabbit model was developed and validated for screening noninvasive candidate decontamination systems for their efficacies against topical exposure to the vesicant chemical surety material sulfur mustard (HD). Rabbits were dosed with HD on their shaved dorsa and then decontaminated at varying times with either both components of the M258A1 field kit or twice with distilled water. Lesion lengths were estimated and compared contralaterally. Results revealed statistically shorter lesions for M258A1 decontamination relative to the respective lesions decontaminated with distilled water.

  19. Serological Survey for RHD Antibodies in Rabbits from Two Types of Rabbit Breeding Farms.

    PubMed

    Fitzner, A; Niedbalski, W

    2016-09-01

    Seroprevalence studies of RHDV antibodies in domestic rabbits were conducted between 2008-2014. A total of 12,169 sera from the provinces of central, southern and south-east Poland, including 7,570 samples collected from mixed-breed rabbits reared in smallholder farms and nearly 4,600 sera taken mainly from unvaccinated rabbits kept in industrial farms, were examined using ELISA tests. Additionally, cross-reactivity of selected tested and control archival sera using both classic RHDV and RHDVa antigens was determined by HI assay. The overall seroprevalence was 13.3%. In rabbits with unkown history of immunisation or RHD infection which came from small farms, RHDV antibodies were detected in 6.1% ranging between 1.0% to 17.2% of animals. In rabbits of the same group, but with a declared vaccination status, or confirmed exposure to an infectious virus, or coming from exposed females, the seroprevalence ranged from 83% to 100%. Among unvaccinated meat rabbits aged 71 to 90 days from industrial farms, low (1.85%, 4.17%, 11%), medium (34%, 54%) or high rates (98.7%) of seropositivity were detected. The seroconversion recorded in adult vaccinated females from industrial farms was 70% and 95%. Generally, the antibody levels examined by ELISAs and HI were comparable. However, a number of sera from the rabbits from small farms, as well as archival sera, showed clear differences. Several-fold differences in antibody titers, evidenced mainly in the postoutbreak sera, indictaed the contact of animals with RHDVa antigen. The overall results of the survey revealed a great proportion of seronegative rabbits potentially highly susceptible to RHD infection. In combination with the emergence of a novel pathogenic RHD virus type (RHDV2), it poses a severe risk of a next wave of fatal disease cases spreading in the native population of domestic rabbits, especially in farms with a traditional system of husbandry.

  20. Dashboard (in the) Knee

    PubMed Central

    Qureshi, AA; Green, TP

    2015-01-01

    We present the case of a 19-year-old individual presenting to an orthopaedic outpatient clinic several months following a dashboard knee injury during a road traffic accident with intermittent mechanical symptoms. Despite unremarkable examination findings and normal magnetic resonance imaging, the patient was identified subsequently as having an intra-articular plastic foreign body consistent with a piece of dashboard on arthroscopic knee assessment, the retrieval of which resulted in a complete resolution of symptoms. PMID:25723676

  1. Viscoelastic properties of rabbit osteoarthritic menisci: A correlation with matrix alterations.

    PubMed

    Levillain, A; Magoariec, H; Boulocher, C; Decambron, A; Viateau, V; Hoc, T

    2017-01-01

    The aim of this study was to evaluate the effect of early osteoarthritis (OA) on the viscoelastic properties of rabbit menisci and to correlate the mechanical alterations with the microstructural changes. Anterior Cruciate Ligament Transection (ACLT) was performed in six male New-Zealand White rabbits on the right knee joint. Six healthy rabbits served as controls. Menisci were removed six weeks after ACLT and were graded macroscopically. Indentation-relaxation tests were performed in the anterior and posterior regions of the medial menisci. The collagen fibre organization and glycosaminoglycan (GAG) content were assessed by biphotonic confocal microscopy and histology, respectively. OA menisci displayed severe macroscopic lesions compared with healthy menisci (p=0.009). Moreover, the instantaneous and equilibrium moduli, which were 2.9±1.0MPa and 0.60±0.18MPa in the anterior region of healthy menisci, respectively, decreased significantly (p=0.03 and p=0.004, respectively) in OA menisci by 55% and 57%, respectively, indicating a global decrease in meniscal stiffness in this region. The equilibrium modulus alone decreased significantly (p=0.04) in the posterior region, going from 0.60±0.18MPa to 0.26±012MPa. This induced a loss of tissue elasticity. These mechanical changes were associated in the posterior region with a structural disruption of the superficial layers, from which the tie fibres emanate, and with a decrease in the GAG content in the anterior region. Consequently, the circumferential collagen fibres of the deep zone were dissociated and the collagen bundles were less compact. Our results demonstrate the strong meniscal modifications induced by ACLT at an early stage of OA and highlight the relationship between structural and chemical matrix alterations and mechanical properties.

  2. Kinematic and dynamic analysis of an anatomically based knee joint.

    PubMed

    Lee, Kok-Meng; Guo, Jiajie

    2010-05-07

    This paper presents a knee-joint model to provide a better understanding on the interaction between natural joints and artificial mechanisms for design and control of rehabilitation exoskeletons. The anatomically based knee model relaxes several commonly made assumptions that approximate a human knee as engineering pin-joint in exoskeleton design. Based on published MRI data, we formulate the kinematics of a knee-joint and compare three mathematical approximations; one model bases on two sequential circles rolling a flat plane; and the other two are mathematically differentiable ellipses-based models with and without sliding at the contact. The ellipses-based model taking sliding contact into accounts shows that the rolling-sliding ratio of a knee-joint is not a constant but has an average value consistent with published measurements. This knee-joint kinematics leads to a physically more accurate contact-point trajectory than methods based on multiple circles or lines, and provides a basis to derive a knee-joint kinetic model upon which the effects of a planar exoskeleton mechanism on the internal joint forces and torque during flexion can be numerically investigated. Two different knee-joint kinetic models (pin-joint approximation and anatomically based model) are compared against a condition with no exoskeleton. The leg and exoskeleton form a closed kinematic chain that has a significant effect on the joint forces in the knee. Human knee is more tolerant than pin-joint in negotiating around a singularity but its internal forces increase with the exoskeleton mass-to-length ratio. An oversimplifying pin-joint approximation cannot capture the finite change in the knee forces due to the singularity effect.

  3. Relationship of Buckling and Knee Injury to Pain Exacerbation in Knee Osteoarthritis: A Web-Based Case-Crossover Study

    PubMed Central

    Zobel, Isabelle; Erfani, Tahereh; Bennell, Kim L; Makovey, Joanna; Metcalf, Ben; March, Lyn; Zhang, Yuqing; Eckstein, Felix

    2016-01-01

    Background Knee osteoarthritis (OA) is one of the most frequent causes of limited mobility and diminished quality of life. Pain is the main symptom that drives individuals with knee OA to seek medical care and a recognized antecedent to disability and eventually joint replacement. Evidence shows that patients with symptomatic OA experience fluctuations in pain severity. Mechanical insults to the knee such as injury and buckling may contribute to pain exacerbation. Objective Our objective was to examine whether knee injury and buckling (giving way) are triggers for exacerbation of pain in persons with symptomatic knee OA. Methods We conducted a case-crossover study, a novel methodology in which participants with symptomatic radiographic knee OA who have had knee pain exacerbations were used as their own control (self-matched design), with all data collected via the Internet. Participants were asked to log-on to the study website and complete an online questionnaire at baseline and then at regular 10-day intervals for 3 months (control periods)—a total of 10 questionnaires. They were also instructed to go to the website and complete pain exacerbation questionnaires when they experienced an isolated incident of knee pain exacerbation (case periods). A pain exacerbation “case” period was defined as an increase of ≥2 compared to baseline. At each contact the pain exacerbation was designated a case period, and at all other regular 10-day contacts (control periods) participants were asked about knee injuries during the previous 7 days and knee buckling during the previous 2 days. The relationship of knee injury and buckling to the risk of pain exacerbation was examined using conditional logistic regression models. Results The analysis included 157 participants (66% women, mean age: 62 years, mean BMI: 29.5 kg/m2). Sustaining a knee injury was associated with experiencing a pain exacerbation (odds ratio [OR] 10.2, 95% CI 5.4, 19.3) compared with no injury. Knee

  4. Exercise and knee osteoarthritis: benefit or hazard?

    PubMed Central

    Bosomworth, Neil J.

    2009-01-01

    ABSTRACT OBJECTIVE To determine whether physical exercise constitutes a benefit or a risk in the development and progression of knee osteoarthritis. QUALITY OF EVIDENCE MEDLINE, EMBASE, DARE, ACP Journal Club, and Cochrane databases were searched from registry inception to January 2009 using MeSH headings or text words, including osteoarthritis, arthritis and knee and exercise, physical training, and run. Reference lists from retrieved articles, citation listings when available, and related articles suggested in PubMed were also evaluated. For individuals without osteoarthritis, strong level II evidence was found (limited by problems with blinding and randomization); for those with pre-existing knee osteoarthritis, robust level I evidence was available. MAIN MESSAGE Knee osteoarthritis is a major contributor to disability in seniors, and patients have expressed concern that continued exercise might lead to knee symptoms in later years. Studies done on subjects self-selected for exercise and followed for substantial periods of time show no evidence of accelerated development of osteoarthritis, provided injury is avoided. Further, there is good evidence for reduced pain and disability with exercise in this cohort compared with controls. Patients with established osteoarthritis are shown to derive uniform benefit to physical functioning, with reduction of pain and disability, using aerobic, muscle strengthening, aquatic, or physiotherapy-based exercise modalities. CONCLUSION Provided trauma is avoided, moderate exercise does not lead to acceleration of knee osteoarthritis, whether or not there is evidence of pre-existing disease. In either case there appears to be improved physical functioning and reduction of pain and disability in those who exercise. It is likely that exercise interventions are underused in the management of established knee osteoarthritis symptoms. PMID:19752252

  5. THE ROLE OF FIBRIN GLUE AND SUTURE ON THE FIXATION OF ULTRA FROZEN PRESERVED MENISCUS TRANSPLANTATION IN RABBITS

    PubMed Central

    Reckers, Leandro José; Fagundes, Djalma José; Pozo Raymundo, José Luiz; Granata Júnior, Geraldo Sérgio de Mello; Moreira, Márcia Bento; Paiva, Vanessa Carla; Negrini Fagundes, Anna Luiza; Cohen, Moises

    2015-01-01

    Objective: To evaluate the ability of fibrin adhesive in promoting the meniscus fixation within two, four and eight weeks compared to the conventional soft-tissue suture technique. Materials and Methods: 36 right medial menisci of rabbits preserved at negative 73° Celsius for 30 days were transplanted to animals of the same sample and fixed with soft-tissue suture or fibrin glue. After 2, 4 or 8 weeks, the appearance of the menisci and the quality of fixation were macroscopically checked and evaluated by a scoring system. The findings were subjected to the statistical study of variance analysis (p ≤ 0.05%). Results: The deep-frozen meniscus preservation maintained the integrity of the meniscus transplant, and, macroscopically, there was no significant reduction of the length of the meniscus in all post-transplant periods (p = 0.015). The menisci fixed with fibrin showed slight changes in color and surface roughness. There were no signs of rejection or infection in both groups. Suture fixation scoring was superior (p = 0.015) in all periods (80% of total fixation) as compared to the setting promoted by fibrin (20% of total fixation). Conclusion: The homologous transplantation of the meniscus of rabbits experienced various degrees of integration to the knee according to the fixation method; the surgical soft tissues suturing technique was shown to be superior in the evaluation of scores compared to the fixation with fibrin adhesive. PMID:27004186

  6. A new rabbit model of implant-related biofilm infection: development and evaluation

    NASA Astrophysics Data System (ADS)

    Chu, Cheng-Bing; Zeng, Hong; Shen, Ding-Xia; Wang, Hui; Wang, Ji-Fang; Cui, Fu-Zhai

    2016-03-01

    This study is to establish a rabbit model for human prosthetic joint infection and biofilm formation. Thirty-two healthy adult rabbits were randomly divided into four groups and implanted with stainless steel screws and ultra-high molecular weight polyethylene (UHMWPE) washers in the non-articular surface of the femoral lateral condyle of the right hind knees. The rabbit knee joints were inoculated with 1 mL saline containing 0, 102, 103, 104 CFU of Staphylococcus epidermidis ( S. epidermidis) isolated from the patient with total knee arthroplasty (TKA) infection, respectively. On the 14th postoperative day, the UHMWPE washers from the optimal 103 CFU group were further examined. The SEM examination showed a typical biofilm construction that circular S. epidermidis were embedded in a mucous-like matrix. In addition, the LCSM examination showed that the biofilm consisted of the polysaccharide stained bright green fluorescence and S. epidermidis radiating red fluorescence. Thus, we successfully create a rabbit model for prosthetic joint infection and biofilm formation, which should be valuable for biofilm studies.

  7. Knee alignment in professional tennis players.

    PubMed

    Maquirriain, Javier

    2002-01-01

    This study determined lower-limb alignment and knee geometry in professional tennis players and compared the data with those from nonathletic individuals. Twenty-four radiographs from 12 asymptomatic players (mean age: 23.4+/-3.8 years) were prospectively studied. The three angles most useful for describing limb alignment and knee geometry in the coronal plane were measured: hip-knee-ankle, condylar-hip, and plateau-ankle. The condylar-plateau angle, frontal foot rotation angle, and the relationship between the mechanical axis and tibial plateau also were calculated. Varus limb alignment was predominant and the mechanical axis passed medially through the knee center; there was increased valgus inclination of the distal femur, varus angulation of the tibial plateau, near parallel alignment of the joint, and exaggerated external foot rotation. Hip-knee-ankle, condylar-hip, plateau-ankle, and frontal foot rotation angles were significantly different (P<.05, two-tailed t test) from previously reported angles of nonathletic individuals. Variations, probably due to repetitive dynamic demands imposed on lower limbs from an early age, seem to involve both femoral condyles and proximal tibial metaphyses, maintaining normal parallel joint alignment.

  8. Cooling Does Not Affect Knee Proprioception

    PubMed Central

    Ozmun, John C.; Thieme, Heather A.; Ingersoll, Christopher D.; Knight, Kenneth L.

    1996-01-01

    The effect of cooling on proprioception of the knee has not been studied extensively. In this study, we investigated the movement reproduction (timing and accuracy) aspect of proprioception. Subjects were tested under two conditions: a 20-minute application of ice and control. Proprioceptive accuracy and timing were measured by passively moving the knee, then comparing the subject's active reproduction of the passive movement. Subjects were blindfolded, then tested in three sectors of the knee's range of motion: 90° to 60°, 60° to 30°, and 30° to full extension. Ice application had no apparent effect on the subject's ability to perform accurate movement reproductions in the sectors tested. However, accuracy of the subject's final angle reproduction varied between the sectors as did the total time of the movement. One possible explanation for the difference between sectors is that different receptors are active at different points in the knee's range of motion. We conclude that cooling the knee joint for 20 minutes does not have an adverse effect on proprioception. PMID:16558379

  9. Cooling does not affect knee proprioception.

    PubMed

    Ozmun, J C; Thieme, H A; Ingersoll, C D; Knight, K L

    1996-01-01

    The effect of cooling on proprioception of the knee has not been studied extensively. In this study, we investigated the movement reproduction (timing and accuracy) aspect of proprioception. Subjects were tested under two conditions: a 20-minute application of ice and control. Proprioceptive accuracy and timing were measured by passively moving the knee, then comparing the subject's active reproduction of the passive movement. Subjects were blindfolded, then tested in three sectors of the knee's range of motion: 90 degrees to 60 degrees , 60 degrees to 30 degrees , and 30 degrees to full extension. Ice application had no apparent effect on the subject's ability to perform accurate movement reproductions in the sectors tested. However, accuracy of the subject's final angle reproduction varied between the sectors as did the total time of the movement. One possible explanation for the difference between sectors is that different receptors are active at different points in the knee's range of motion. We conclude that cooling the knee joint for 20 minutes does not have an adverse effect on proprioception.

  10. Robotic Total Knee Arthroplasty: Surgical Assistant for a Customized Normal Kinematic Knee.

    PubMed

    Urish, Kenneth L; Conditt, Michael; Roche, Martin; Rubash, Harry E

    2016-09-01

    Although current total knee arthroplasty (TKA) is considered a highly successful surgical procedure, patients undergoing TKA can still experience substantial functional impairment and increased revision rates as compared with those undergoing total hip arthroplasty. Robotic-assisted surgery has been available clinically for almost 15 years and was developed, in part, to address these concerns. Robotic-assisted surgery aims to improve TKA by enhancing the surgeon's ability to optimize soft tissue balancing, reproduce alignment, and restore normal knee kinematics. Current systems include a robotic arm with a variety of different navigation systems with active, semi-active, or passive control. Semi-active systems have become the dominant strategy, providing a haptic window through which the surgeon consistently prepares a TKA based on preoperative planning. A review of previous designs and clinical studies demonstrates that these robotic systems decrease variability and increase precision, primarily with the mechanical axis and restoration of the joint line. Future design objectives include precise planning and consistent intraoperative execution. Preoperative planning, intraoperative sensors, augmenting surgical instrumentation, and biomimetic surfaces will be used to re-create the 4-bar linkage system in the knee. Implants will be placed so that the knee functions with a medial pivot, lateral rollback, screw home mechanism, and patellar femoral tracking. Soft tissue balancing will become more than equalizing the flexion and extension gaps and will match the kinematics to a normal knee. Together, coupled with advanced knee designs, they may be the key to a patient stating, "My knee feels like my natural knee." [Orthopedics. 2016; 39(5):e822-e827.].

  11. Cutaneous lymphomas in European pet rabbits (Oryctolagus cuniculus).

    PubMed

    Ritter, J M; von Bomhard, W; Wise, A G; Maes, R K; Kiupel, M

    2012-09-01

    Cutaneous lymphoma is a common skin neoplasm of pet rabbits in Europe but is rarely reported in pet rabbits in North America. These neoplasms have not been previously characterized, nor has the cause for the apparent predilection for cutaneous lymphoma in European pet rabbits compared with North American pet rabbits been investigated. In this retrospective study, the authors morphologically and immunohistochemically characterized 25 cutaneous lymphomas in European pet rabbits according to the World Health Organization classification. Tumors were classified as diffuse large B cell lymphomas, with 14 lymphomas exhibiting a centroblastic/centrocytic subtype and 11 tumors exhibiting a T cell-rich B cell subtype. To investigate a potential viral etiology of these lymphomas, 3 diffuse large B cell and 3 T cell-rich B cell lymphomas were evaluated by polymerase chain reaction for retroviral and herpesviral genes. Neither virus was detected. In contrast to other domestic animals, cutaneous lymphomas in European pet rabbits were highly pleomorphic and frequently contained multinucleated giant cells. Unexpectedly, the second most common subtype was T cell-rich B cell lymphoma, a subtype that is rare in species other than horses. Based on a limited number of samples, there was no support for a viral etiology that would explain the higher incidence of lymphoma in European pet rabbits compared with American pet rabbits. Further investigation into genetic and extrinsic factors associated with the development of these tumors is warranted.

  12. Interpolation function for approximating knee joint behavior in human gait

    NASA Astrophysics Data System (ADS)

    Toth-Taşcǎu, Mirela; Pater, Flavius; Stoia, Dan Ioan

    2013-10-01

    Starting from the importance of analyzing the kinematic data of the lower limb in gait movement, especially the angular variation of the knee joint, the paper propose an approximation function that can be used for processing the correlation among a multitude of knee cycles. The approximation of the raw knee data was done by Lagrange polynomial interpolation on a signal acquired using Zebris Gait Analysis System. The signal used in approximation belongs to a typical subject extracted from a lot of ten investigated subjects, but the function domain of definition belongs to the entire group. The study of the knee joint kinematics plays an important role in understanding the kinematics of the gait, this articulation having the largest range of motion in whole joints, in gait. The study does not propose to find an approximation function for the adduction-abduction movement of the knee, this being considered a residual movement comparing to the flexion-extension.

  13. Walking ability following knee arthroplasty: a prospective pilot study of factors affecting the maximal walking distance in 18 patients before and 6 months after total knee arthroplasty.

    PubMed

    Rosenberg, N; Nierenberg, G; Lenger, R; Soudry, M

    2007-12-01

    Functional assessment of patients before and after prosthetic knee arthroplasty is based on clinical examination, which is usually summarized in various knee scores. The present study proposes a different and more subject orientated assessment for functional grading of these patients by measuring their maximal distance of walking ability, which is not apparent from the conventional outcome scores. Eighteen consecutive patients with knee osteoarthritis were evaluated for their knee and knee functional scores (The Knee Society clinical rating system) and for the maximal distance of their walking ability before and 6 months after knee arthroplasty. Specially designed walking ability grading was used for evaluation of walking on walkway. The pre- and post-operative knee scores and maximal walking distance and grading were statistically compared. A significant improvement in the knee and functional scores following surgery was observed. But the maximal walking ability grades and distances did not change significantly following surgery, showing a high relation between pre- and post-operative values. The limitation in post-operative walking was due to the revealed additional health disabilities, not related to the affected knee. Therefore we suggest that pre-operative evaluation of walking abilities should be taken into consideration both for patients' selection and timing of surgery and also for matching of patients' expectation from outcome of prosthetic knee arthroplasty.

  14. Development of a Zealand white rabbit deposition model to study inhalation anthrax.

    PubMed

    Asgharian, Bahman; Price, Owen; Kabilan, Senthil; Jacob, Richard E; Einstein, Daniel R; Kuprat, Andrew P; Corley, Richard A

    2016-01-01

    Despite using rabbits in several inhalation exposure experiments to study diseases such as anthrax, there is a lack of understanding regarding deposition characteristics and fate of inhaled particles (bio-aerosols and viruses) in the respiratory tracts of rabbits. Such information allows dosimetric extrapolation to humans to inform human outcomes. The lung geometry of the New Zealand white rabbit (referred to simply as rabbits throughout the article) was constructed using recently acquired scanned images of the conducting airways of rabbits and available information on its acinar region. In addition, functional relationships were developed for the lung and breathing parameters of rabbits as a function of body weight. The lung geometry and breathing parameters were used to extend the existing deposition model for humans and several other species to rabbits. Evaluation of the deposition model for rabbits was made by comparing predictions with available measurements in the literature. Deposition predictions in the lungs of rabbits indicated smaller deposition fractions compared to those found in humans across various particle diameter ranges. The application of the deposition model for rabbits was demonstrated by extrapolating deposition predictions in rabbits to find equivalent human exposure concentrations assuming the same dose-response relationship between the two species. Human equivalent exposure concentration levels were found to be much smaller than those for rabbits.

  15. Development of a Zealand white rabbit deposition model to study inhalation anthrax

    SciTech Connect

    Asgharian, Bahman; Price, Owen; Kabilan, Senthil; Jacob, Richard E.; Einstein, Daniel R.; Kuprat, Andrew P.; Corley, Richard A.

    2016-01-28

    Despite using rabbits in several inhalation exposure experiments to study diseases such as anthrax, there is a lack of understanding regarding deposition characteristics and fate of inhaled particles (bio-aerosols and viruses) in the respiratory tracts of rabbits. Such information allows dosimetric extrapolation to humans to inform human outcomes. The lung geometry of the New Zealand white rabbit (referred to simply as rabbits throughout the article) was constructed using recently acquired scanned images of the conducting airways of rabbits and available information on its acinar region. In addition, functional relationships were developed for the lung and breathing parameters of rabbits as a function of body weight. The lung geometry and breathing parameters were used to extend the existing deposition model for humans and several other species to rabbits. Evaluation of the deposition model for rabbits was made by comparing predictions with available measurements in the literature. Deposition predictions in the lungs of rabbits indicated smaller deposition fractions compared to those found in humans across various particle diameter ranges. The application of the deposition model for rabbits was demonstrated by extrapolating deposition predictions in rabbits to find equivalent human exposure concentrations assuming the same dose-response relationship between the two species. Human equivalent exposure concentration levels were found to be much smaller than those for rabbits.

  16. Performance of subjects with knee osteoarthritis during walking: differential parameters.

    PubMed

    Esrafilian, Amir; Karimi, Mohammad Taghi; Amiri, Pouya; Fatoye, Francis

    2013-07-01

    The effect of knee OA on kinetic and kinematic parameters during walking and standing is still controversial. Stability and energy consumption have not been well investigated in patients with OA. This research investigated the parameters distinguishing between the healthy subjects and patients with OA performance. It also examined the differences in stability and energy consumption between patients with OA and healthy subjects. Fifteen patients with OA and fifteen healthy subjects were recruited into this study. Kinematic and kinetic assessments were performed using Qualysis motion analysis and a force plate Kistler, respectively. Stability of the subjects during walking was determined using COP. Energy consumption was calculated using the Physiological Index. Independent t test was used to determine the differences between gait, stability, and energy consumption healthy participants and patients with knee OA. The excursion of the knee, hip and pelvis in sagittal plane, excursion of the knee joint in the mediolateral plane were significantly higher (all p < 0.05) in patients with OA of the knee compared with their healthy counterparts. In addition, energy consumption was significantly higher in patients with OA (p = 0.009) than in healthy participants. However, margin of stability was significantly lower (p = 0.05) in patients with OA of the knee than in healthy subjects. These findings suggest that gait parameters and energy consumption assessments may be important in patients with OA of the knee. Therefore, clinicians are to be aware of these findings by developing appropriate gait rehabilitation for patients with OA of the knee.

  17. The elephant knee joint: morphological and biomechanical considerations

    PubMed Central

    Weissengruber, G E; Fuss, F K; Egger, G; Stanek, G; Hittmair, K M; Forstenpointner, G

    2006-01-01

    Elephant limbs display unique morphological features which are related mainly to supporting the enormous body weight of the animal. In elephants, the knee joint plays important roles in weight bearing and locomotion, but anatomical data are sparse and lacking in functional analyses. In addition, the knee joint is affected frequently by arthrosis. Here we examined structures of the knee joint by means of standard anatomical techniques in eight African (Loxodonta africana) and three Asian elephants (Elephas maximus). Furthermore, we performed radiography in five African and two Asian elephants and magnetic resonance imaging (MRI) in one African elephant. Macerated bones of 11 individuals (four African, seven Asian elephants) were measured with a pair of callipers to give standardized measurements of the articular parts. In one Asian and three African elephants, kinematic and functional analyses were carried out using a digitizer and according to the helical axis concept. Some peculiarities of healthy and arthrotic knee joints of elephants were compared with human knees. In contrast to those of other quadruped mammals, the knee joint of elephants displays an extended resting position. The femorotibial joint of elephants shows a high grade of congruency and the menisci are extremely narrow and thin. The four-bar mechanism of the cruciate ligaments exists also in the elephant. The main motion of the knee joint is extension–flexion with a range of motion of 142°. In elephants, arthrotic alterations of the knee joint can lead to injury or loss of the cranial (anterior) cruciate ligament. PMID:16420379

  18. The effect of different types of insoles or shoe modifications on medial loading of the knee in persons with medial knee osteoarthritis: a randomised trial

    PubMed Central

    Chapman, Graham J.; Parkes, Matthew J.; Forsythe, Laura.; Felson, David T.

    2015-01-01

    ABSTRACT Many conservative treatments exist for medial knee osteoarthritis (OA) which aims to reduce the external knee adduction moment (EKAM). The objective of this study was to determine the difference between different shoes and lateral wedge insoles on EKAM, knee adduction angular impulse (KAAI), external knee flexion moment, pain, and comfort when walking in individuals with medial knee OA. Seventy individuals with medial knee OA underwent three‐dimensional walking gait analysis in five conditions (barefoot, control shoe, typical wedge, supported wedge, and mobility shoe) with pain and comfort recorded concurrently. The change in EKAM, KAAI, external knee flexion moment, pain, and comfort were assessed using multiple linear regressions and pairwise comparisons. Compared with the control shoe, lateral wedge insoles and barefoot walking significantly reduced early stance EKAM and KAAI. The mobility shoe showed no effect. A significant reduction in latter stance EKAM was seen in the lateral wedge insoles compared to the other conditions, with only the barefoot condition reducing the external knee flexion moment. However, the mobility shoe showed significant immediate knee pain reduction and improved comfort scores. Different lateral wedge insoles show comparable reductions in medial knee loading and in our study, the mobility shoe did not affect medial loading. © 2015 The Authors. Journal of Orthopaedic Research Published by Wiley Periodicals, Inc. J Orthop Res 33:1646–1654, 2015. PMID:25991385

  19. The effect of different types of insoles or shoe modifications on medial loading of the knee in persons with medial knee osteoarthritis: a randomised trial.

    PubMed

    Jones, Richard K; Chapman, Graham J; Parkes, Matthew J; Forsythe, Laura; Felson, David T

    2015-11-01

    Many conservative treatments exist for medial knee osteoarthritis (OA) which aims to reduce the external knee adduction moment (EKAM). The objective of this study was to determine the difference between different shoes and lateral wedge insoles on EKAM, knee adduction angular impulse (KAAI), external knee flexion moment, pain, and comfort when walking in individuals with medial knee OA. Seventy individuals with medial knee OA underwent three-dimensional walking gait analysis in five conditions (barefoot, control shoe, typical wedge, supported wedge, and mobility shoe) with pain and comfort recorded concurrently. The change in EKAM, KAAI, external knee flexion moment, pain, and comfort were assessed using multiple linear regressions and pairwise comparisons. Compared with the control shoe, lateral wedge insoles and barefoot walking significantly reduced early stance EKAM and KAAI. The mobility shoe showed no effect. A significant reduction in latter stance EKAM was seen in the lateral wedge insoles compared to the other conditions, with only the barefoot condition reducing the external knee flexion moment. However, the mobility shoe showed significant immediate knee pain reduction and improved comfort scores. Different lateral wedge insoles show comparable reductions in medial knee loading and in our study, the mobility shoe did not affect medial loading.

  20. Short-interval two-stage approach to primary total knee arthroplasty for acutely septic osteoarthritic knees.

    PubMed

    Hochreiter, Bettina; Strahm, Carol; Behrend, Henrik

    2016-10-01

    Treatment strategies for advanced knee osteoarthritis with coexistent joint infection are not well established. While in periprosthetic joint infection the two-stage approach has been studied extensively, only few case reports on two-stage total knee arthroplasty (TKA) for knee osteoarthritis with coexistent joint infection have been published. The purpose of this paper was to report on our method of implementing a two-stage TKA with intervening antibiotic-loaded articulating cement spacers and a short interval between first- and second-stage procedures to treat two patients with Staphylococcus aureus-infected end-stage knee osteoarthritis. Consistent infection eradication was found at a 1-year follow-up with postoperative range of motion and knee scores comparing favourably with those of other case series. Level of evidence V.

  1. Antagonistic active knee prosthesis. A metabolic cost of walking comparison with a variable-damping prosthetic knee.

    PubMed

    Martinez-Villalpando, Ernesto C; Mooney, Luke; Elliott, Grant; Herr, Hugh

    2011-01-01

    This paper examines the impact of a biomimetic active knee prosthesis on the metabolic costs associated with a unilateral transfemoral amputee walking at self selected speed. In this study we compare the antagonistic active knee prosthesis developed at MIT to an electronically controlled, variable-damping commercial knee prosthesis, the Otto Bock C-leg. Use of the active knee prosthesis resulted in both, a 17% increase in an amputee's average self selected walking speed from 1.12 m/s to 1.31 m/s, and a 6.8% reduction in metabolic cost. The results of this study suggest that an agonist-antagonist active knee prosthesis design with variable impedance control can offer walking energetic advantages over commercially available systems.

  2. Runner's knee injuries.

    PubMed

    Lutter, L D

    1984-01-01

    In our series of running injuries 40% of all injuries have been related to the knee area. Over 20 million people in the United States run on a regular basis. Figures from large running sources show that 60% to 70% of individuals running regularly are injured severely enough to temporarily stop running. The figures are significant, not in the seriousness of the knee injury, but in the fact that seeking treatment for their knee problems. Orthopaedic surgeons, because of their ability to evaluate the entire lower extremity, become the central component for treatment of this large group of injured runners. As has been noted, the underlying biomechanical abnormality must be sought and dealt with or the symptoms return. By identification of the injured structure(s) integrated with biomechanical understanding, treatment can be developed on a rational basis, dealing with acute problems and prevention of future ones.

  3. Interlimb symmetry of dynamic knee joint stiffness and co-contraction is maintained in early stage knee osteoarthritis.

    PubMed

    Collins, A T; Richardson, R T; Higginson, J S

    2014-08-01

    Individuals with knee OA often exhibit greater co-contraction of antagonistic muscle groups surrounding the affected joint which may lead to increases in dynamic joint stiffness. These detrimental changes in the symptomatic limb may also exist in the contralateral limb, thus contributing to its risk of developing knee osteoarthritis. The purpose of this study is to investigate the interlimb symmetry of dynamic knee joint stiffness and muscular co-contraction in knee osteoarthritis. Muscular co-contraction and dynamic knee joint stiffness were assessed in 17 subjects with mild to moderate unilateral medial compartment knee osteoarthritis and 17 healthy control subjects while walking at a controlled speed (1.0m/s). Paired and independent t-tests determined whether significant differences exist between groups (p<0.05). There were no significant differences in dynamic joint stiffness or co-contraction between the OA symptomatic and OA contralateral group (p=0.247, p=0.874, respectively) or between the OA contralateral and healthy group (p=0.635, p=0.078, respectively). There was no significant difference in stiffness between the OA symptomatic and healthy group (p=0.600); however, there was a slight trend toward enhanced co-contraction in the symptomatic knees compared to the healthy group (p=0.051). Subjects with mild to moderate knee osteoarthritis maintain symmetric control strategies during gait.

  4. Knee kinematics during walking at different speeds in people who have undergone total knee replacement.

    PubMed

    McClelland, Jodie A; Webster, Kate E; Feller, Julian A; Menz, Hylton B

    2011-06-01

    People who have undergone total knee replacement (TKR) experience difficulties in some daily activities including walking. Walking at faster speeds requires more knee flexion and may therefore present a greater challenge following TKR. The aim of this study was to compare the knee kinematics of patients following TKR and unimpaired controls during comfortable and fast walking speeds. Forty patients (22 women, 18 men) 12 months following TKR and 40 control participants (matched for age and sex) were assessed during walking at self-selected comfortable and fast speeds using three dimensional motion analysis. The group averages of spatiotemporal and peak kinematic characteristics in the sagittal, coronal and transverse movement planes were compared using univariate analysis of variance with walking speed as a co-variate. The TKR group walked with significantly reduced cadence (p < 0.001 at both speeds) and reduced stride length (p < 0.001 at both speeds), less knee flexion during stance and swing phases (p < 0.001 for both speeds) and less knee extension during stance phase (p < 0.024 for comfortable speed; p < 0.042 for fast speed). The TKR group also walked with less peak knee external rotation than controls at both speeds (p < 0.001 for both speeds). Both groups increased their velocity, cadence and stride length by a similar proportion when walking at fast speed. When walking at a faster speed, spatiotemporal gait parameters and knee motion are altered in a similar manner for both TKR patients and controls. However, at both walking speeds, TKR patients exhibit residual deficits 12 months following surgery.

  5. Sclareol exerts anti-osteoarthritic activities in interleukin-1β-induced rabbit chondrocytes and a rabbit osteoarthritis model.

    PubMed

    Zhong, Ying; Huang, Yi; Santoso, Marcel B; Wu, Li-Dong

    2015-01-01

    Sclareol is a natural product initially isolated form Salvia sclarea which possesses immune-regulation and anti-inflammatory activities. However, the anti-osteoarthritic properties of sclareol have not been investigated. The present study is aimed at evaluating the potential effects of sclareol in interleukin-1β (IL-1β)-induced rabbit chondrocytes as well as an experimental rabbit knee osteoarthritis model induced by anterior cruciate ligament transection (ACLT). Cultured rabbit chondrocytes were pretreated with 1, 5 and 10 μg/mL sclareol for 1 h and followed by stimulation of IL-1β (10 ng/mL) for 24 h. Gene expression of matrix metalloproteinase-1 (MMP-1), MMP-3, MMP-13, tissue inhibitors of metalloproteinase-1 (TIMP-1), inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 was determined by quantitative real-time polymerase chain reaction (qRT-PCR). MMP-3, TIMP-1, iNOS and COX-2 proteins were measured by Western blotting. Enzyme-linked immunosorbent assay (ELISA) was applied for nitric oxide (NO) and prostaglandin E2 (PGE2) assessment. For the in vivo study, rabbits received six weekly 0.3 mL sclareol (10 μg/mL) intra-articular injections in the knees four weeks after ACLT surgery. Cartilage was harvested for measurement of MMP-1, MMP-3, MMP-13, TIMP-1, iNOS and COX-2 by qRT-PCR, while femoral condyles were used for histological evaluation. The in vitro results we obtained showed that sclareol inhibited the MMPs, iNOS and COX-2 expression on mRNA and protein levels, while increased the TIMP-1 expression. And over-production of NO and PGE2 was also suppressed. For the in vivo study, both qRT-PCR results and histological evaluation confirmed that sclareol ameliorated cartilage degradation. Hence, we speculated that sclareol may be an ideal approach for treating osteoarthritis.

  6. Wear analysis of unicondylar mobile bearing and fixed bearing knee systems: a knee simulator study.

    PubMed

    Kretzer, J Philippe; Jakubowitz, Eike; Reinders, Jörn; Lietz, Eva; Moradi, Babak; Hofmann, Kerstin; Sonntag, Robert

    2011-02-01

    Unicondylar knee arthroplasty is an attractive alternative to total knee arthroplasty for selected patients with osteoarthritis. Mobile bearing knee designs have been developed to improve knee kinematics, lower contact stresses and reduced wear of ultra-high molecular weight polyethylene compared with fixed bearing designs. This study compared in vitro wear behavior of fixed and mobile unicondylar bearing designs. Analysis was performed using a force-controlled AMTI knee simulator according to ISO 14243-1:2002(E). The wear volume of the implants was determined gravimetrically. Optical surface characterization and an estimation of wear particle size and morphology were performed. Implant kinematic data for both designs were determined. The wear rates averaged 10.7 ± 0.59 mg per 10(6) cycles for the medial and 5.38 ± 0.63 mg per 10(6) cycles for the lateral components of the mobile bearings, compared with 7.51 ± 0.29 mg per 10(6) cycles and 3.04 ± 0.35 mg per 10(6) cycles for the fixed bearings. The mobile bearings therefore exhibited higher wear rates (P<0.01) compared with the fixed bearings. The tibial polyethylene inserts of the mobile bearings showed pronounced backside wear at the inferior surface. The kinematics of both designs was similar. However, anterior-posterior translation was lower in the mobile bearings. The wear particles were mainly elongated and small in size for both designs (P=0.462). This study shows that wear may play an important role in unicondylar mobile bearing knee designs. Advantages of unicondylar mobile designs compared with fixed bearing designs, which have been proposed in terms of wear behavior and improved kinematics, could not be confirmed.

  7. Influence of Total Knee Arthroplasty on Gait Mechanics of the Replaced and Non-Replaced Limb During Stair Negotiation.

    PubMed

    Standifird, Tyler W; Saxton, Arnold M; Coe, Dawn P; Cates, Harold E; Reinbolt, Jeffrey A; Zhang, Songning

    2016-01-01

    This study compared biomechanics during stair ascent in replaced and non-replaced limbs of total knee arthroplasty (TKA) patients with control limbs of healthy participants. Thirteen TKA patients and fifteen controls performed stair ascent. Replaced and non-replaced knees of TKA patients were less flexed at contact compared to controls. The loading response peak knee extension moment was greater in control and non-replaced knees compared with replaced. The push-off peak knee abduction moment was elevated in replaced limbs compared to controls. Loading and push-off peak hip abduction moments were greater in replaced limbs compared to controls. The push-off peak hip abduction moment was greater in non-replaced limbs compared to controls. Future rehabilitation protocols should consider the replaced knee and also the non-replaced knee and surrounding joints.

  8. Image based weighted center of proximity versus directly measured knee contact location during simulated gait

    PubMed Central

    Wang, Hongsheng; Chen, Tony; Koff, Matthew F.; Hutchinson, Ian D.; Gilbert, Susannah; Choi, Dan; Warren, Russell F.; Rodeo, Scott A.; Maher, Suzanne A.

    2014-01-01

    To understand the mechanical consequences of knee injury requires a detailed analysis of the effect of that injury on joint contact mechanics during activities of daily living. Three-dimensional (3D) knee joint geometric models have been combined with knee joint kinematics to dynamically estimate the location of joint contact during physiological activities – using a weighted center of proximity (WCoP) method. However, the relationship between the estimated WCoP and the actual location of contact has not been defined. The objective of this study was to assess the relationship between knee joint contact location as estimated using the image-based WCoP method, and a directly measured weighted center of contact (WCoC) method during simulated walking. To achieve this goal, we created knee specific models of six human cadaveric knees from magnetic resonance imaging. All knees were then subjected to physiological loads on a knee simulator intended to mimic gait. Knee joint motion was captured using a motion capture system. Knee joint contact stresses were synchronously recorded using a thin electronic sensor throughout gait, and used to compute WCoC for the medial and lateral plateaus of each knee. WCoP was calculated by combining knee kinematics with the MRI-based knee specific model. Both metrics were compared throughout gait using linear regression. The anteroposterior (AP) location of WCoP was significantly correlated with that of WCoC on both tibial plateaus in all specimens (P < 0.01, 95% confidence interval of Person’s coefficient r > 0), but the correlation was not significant in the mediolateral (ML) direction for 4/6 knees (P > 0.05). Our study demonstrates that while the location of joint contact obtained from 3D knee joint contact model, using the WCoP method, is significantly correlated with the location of actual contact stresses in the AP direction, that relationship is less certain in the ML direction. PMID:24837219

  9. Reading Knee-Deep

    ERIC Educational Resources Information Center

    Jewett, Pamela

    2007-01-01

    Freire told his audience at a seminar at the University of Massachusetts, "You need to read knee-deep in texts, for deeper than surface meanings, and you need to know the words to be able to do it" (quoted in Cleary, 2003). In a children's literature class, fifteen teachers and I traveled along a path that moved us toward reading…

  10. Hypermobility and Knee Injuries.

    ERIC Educational Resources Information Center

    Steiner, Mark E.

    1987-01-01

    A review of research on the effect of hypermobility on knee injury indicates that greater than normal joint flexibility may be necessary for some athletic endeavors and that it may be possible to change one's underlying flexibility through training. However, for most athletes, inherited flexibility probably plays only a small role, if any, in…

  11. Custom Knee Device for Knee Contractures After Internal Femoral Lengthening.

    PubMed

    Bhave, Anil; Shabtai, Lior; Ong, Peck-Hoon; Standard, Shawn C; Paley, Dror; Herzenberg, John E

    2015-07-01

    The development of knee flexion contractures is among the most common problems and complications associated with lengthening the femur with an internal device or external fixator. Conservative treatment strategies include physical therapy, serial casting, and low-load prolonged stretching with commercially available splinting systems. The authors developed an individually molded, low-cost custom knee device with polyester synthetic conformable casting material to treat knee flexion contractures. The goal of this study was to evaluate the results of treatment with a custom knee device and specialized physical therapy in patients who had knee flexion contracture during femoral lengthening with an intramedullary lengthening femoral nail. This retrospective study included 23 patients (27 limbs) who underwent femoral lengthening with an internal device for the treatment of limb length discrepancy. All patients had a knee flexion contracture raging from 10° to 90° during the lengthening process and were treated with a custom knee device and specialized physical therapy. The average flexion contracture before treatment was 36°. The mean amount of lengthening was 5.4 cm. After an average of 3.8 weeks of use of the custom knee device, only 2 of 27 limbs (7.5%) had not achieved complete resolution of the flexion contracture. The average final extension was 1.4°. Only 7 of 27 limbs (26%) required additional soft tissue release. The custom knee device is an inexpensive and effective method for treating knee flexion contracture after lengthening with an internal device.

  12. Impact of environmental factors on knee injuries in male and female recreational skiers.

    PubMed

    Ruedl, G; Fink, C; Schranz, A; Sommersacher, R; Nachbauer, W; Burtscher, M

    2012-04-01

    In alpine skiing, the knee represents the dominant injury location with marked gender differences. Snow, slope and weather conditions as well as altitude and low temperatures are thought to influence the prevalence of knee injuries. Therefore, ski patrol injury reports were used to compare gender-specific prevalence of knee injuries with regard to several environmental factors including the actual air temperatures. A total of 1039 non-contact knee injuries were reported with a corresponding prevalence of knee injuries of 44.4% (males: 30.1%; females: 57.4%). Temperature quartiles of all recorded injuries were calculated to compare gender-specific prevalence of knee injury with regard to temperatures. Comparing the first quartile (mean temperature -11°C) with the fourth quartile (mean temperature +3°C), the prevalence of knee injury in female skiers was higher at low ambient temperatures (61% vs 50%, odds ratio: 1.60, 95% confidence interval: 1.16-2.22; P=0.005) while no such association was found for male skiers. Additionally, knee-injured females showed a twofold prevalence when skiing during snowfall compared with females with other injuries (15.4% vs 8.6%; P=0.001). No other environmental factor showed a significant association with the gender-specific prevalence of knee injury. In conclusion, low ambient temperature and snowfall are important environmental risk factors for knee injuries in female skiers.

  13. The Cutaneous Rabbit Revisited

    ERIC Educational Resources Information Center

    Flach, Rudiger; Haggard, Patrick

    2006-01-01

    In the cutaneous rabbit effect (CRE), a tactile event (so-called attractee tap) is mislocalized toward an adjacent attractor tap. The effect depends on the time interval between the taps. The authors delivered sequences of taps to the forearm and asked participants to report the location of one of the taps. The authors replicated the original CRE…

  14. Autoantibody Production in Rabbits

    PubMed Central

    Asherson, G. L.; Dumonde, D. C.

    1963-01-01

    The sera of rabbits injected with rat liver, kidney, heart, muscle, spleen and brain in Freund's complete adjuvant fixed complement with rabbit tissue. This complement-fixing activity was attributed to autoantibodies which were able to fix complement in vitro with the tissue of the rabbit in which they occurred. Absorption, gel diffusion and antibody and antigen titrations indicated that some of the anti-liver, anti-kidney, anti-heart, anti-muscle and anti-brain sera contained organ-specific autoantibody. The sera also contained autoantibody reacting with widely distributed antigen(s), which was relatively labile at 65°. The anti-kidney and anti-brain sera reacted with distinct antigens which were extracted from rabbit kidney and brain with a mixture of chloroform and methanol. The natural autoantibody of Kidd and Friedewald was usually labile at 65° and behaved like a macroglobulin on sucrose gradient centrifugation. Sera taken 1 week after immunization with rat tissue contained heat-labile macroglobulin antibody. However, sera taken 1 month after immunization also contained small molecular weight antibody which was stable at 65°. PMID:13965166

  15. A case of low success of blind vaccination campaigns against myxomatosis and rabbit haemorrhagic disease on survival of adult European wild rabbits.

    PubMed

    Rouco, Carlos; Moreno, Sacramento; Santoro, Simone

    2016-10-01

    Vaccination campaigns against myxomatosis and rabbit haemorrhagic disease (RHD) are commonly used in translocation programs conducted for the purpose of recovering wild European rabbit populations in Iberian Mediterranean ecosystems. In most cases rabbits are vaccinated 'blind' (i.e. without assessing their prior immunological status) for economic and logistic reasons. However, there is conflicting evidence on the effectiveness of such an approach. We tested whether blind vaccination against myxomatosis and rabbit haemorrhagic disease improved rabbit survival in a rabbit translocation program where wild rabbits were kept in semi-natural conditions in three enclosures. We conducted nine capture sessions over two years (2008-2010) and used the information collected to compare the survival of vaccinated (n=511) versus unvaccinated (n=161) adult wild rabbits using capture-mark-recapture analysis. Average monthly survival was no different for vaccinated versus unvaccinated individuals, both in the period between release and first capture (short-term) and after the first capture onward (long-term). Rabbit survival was lower in the short term than in the long term regardless of whether rabbits were vaccinated or not. Lower survival in the short-term could be due to the stress induced by the translocation process itself (e.g. handling stress). However, we did not find any overall effect of vaccination on survival which could be explained by two non-exclusive reasons. First, interference of the vaccine with the natural antibodies in the donor population. Due to donor populations have high density of rabbits with, likely, high prevalence of antibodies as a result of previous natural exposure to these diseases. Second, the lack of severe outbreaks during the study period. Based on our findings we argue that blind vaccination of adult rabbits in translocation programs may be often mostly ineffective and unnecessarily costly. In particular, since outbreaks are hard to predict

  16. Decreased Knee Joint Loading Associated With Early Knee Osteoarthritis After Anterior Cruciate Ligament Injury

    PubMed Central

    Wellsandt, Elizabeth; Gardinier, Emily S.; Manal, Kurt; Axe, Michael J.; Buchanan, Thomas S.; Snyder-Mackler, Lynn

    2015-01-01

    Background Anterior cruciate ligament (ACL) injury predisposes individuals to early-onset knee joint osteoarthritis (OA). Abnormal joint loading is apparent after ACL injury and reconstruction. The relationship between altered joint biomechanics and the development of knee OA is unknown. Hypothesis Altered knee joint kinetics and medial compartment contact forces initially after injury and reconstruction are associated with radiographic knee OA 5 years after reconstruction. Study Design Case-control study; Level of evidence, 3. Methods Individuals with acute, unilateral ACL injury completed gait analysis before (baseline) and after (posttraining) preoperative rehabilitation and at 6 months, 1 year, and 2 years after reconstruction. Surface electromyographic and knee biomechanical data served as inputs to an electromyographically driven musculoskeletal model to estimate knee joint contact forces. Patients completed radiographic testing 5 years after reconstruction. Differences in knee joint kinetics and contact forces were compared between patients with and those without radiographic knee OA. Results Patients with OA walked with greater frontal plane interlimb differences than those without OA (nonOA) at baseline (peak knee adduction moment difference: 0.00 ± 0.08 N·m/kg·m [nonOA] vs −0.15 ± 0.09 N·m/kg·m [OA], P = .014; peak knee adduction moment impulse difference: −0.001 ± 0.032 N·m·s/kg·m [nonOA] vs −0.048 ± 0.031 N·m·s/kg·m [OA], P = .042). The involved limb knee adduction moment impulse of the group with osteoarthritis was also lower than that of the group without osteoarthritis at baseline (0.087 ± 0.023 N·m·s/kg·m [nonOA] vs 0.049 ± 0.018 N·m·s/kg·m [OA], P = .023). Significant group differences were absent at posttraining but reemerged 6 months after reconstruction (peak knee adduction moment difference: 0.02 ± 0.04 N·m/kg·m [nonOA] vs −0.06 ± 0.11 N·m/kg·m [OA], P = .043). In addition, the OA group walked with lower peak

  17. Autoantibody production in rabbits

    PubMed Central

    Asherson, G. L.; Holborow, E. J.

    1966-01-01

    Rabbits received two injections of dead bacteria in Freund's complete adjuvant. One month later the sera of the rabbits were examined for autoantibodies against gut by indirect immunofluorescence using the rabbit's own stomach, ileum and colon taken at post mortem. Autoantibodies against colon were found in three out of seven rabbits injected with one particular strain of Escherichia coli O64 and in a few animals injected with other E. coli, Salmonella arizona, Proteus mirabilis, Klebsiella pneumoniae and Streptococcus faecalis. The antigen, with which the autoantibodies reacted, behaved like mucus and was detected in the colon and sometimes in the ileum and the stomach. Three patterns of staining were observed: (a) staining of the superficial mucosa of the colon with sparing of the deep glands; (b) staining of scattered groups of glands in the deepest part of the colon with sparing of the superficial glands (this pattern of staining was associated with staining of the superficial mucosa of the body of the stomach); and (c) staining of both the superficial and deep glands of the colon. None of the sera tested reacted with the bronchial or salivary glands. Polysaccharide preparations of the colon, but not the stomach, inhibited the reaction of the autoantibodies with colon in the sera tested. The amount of antigen needed to inhibit the basal staining was much greater than that needed to inhibit the superficial staining. It was concluded that rabbits may produce autoantibodies to colon and in some cases to ileum and stomach following the injection of certain dead bacteria in Freund's complete adjuvant. ImagesFIGS. 1-2FIG. 3FIG. 4FIG. 5FIG. 6 PMID:4956607

  18. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be...

  19. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be...

  20. 21 CFR 888.3580 - Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Knee joint patellar (hemi-knee) metallic... § 888.3580 Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis is a device made...

  1. 21 CFR 888.3580 - Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Knee joint patellar (hemi-knee) metallic... § 888.3580 Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis is a device made...

  2. 21 CFR 888.3580 - Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Knee joint patellar (hemi-knee) metallic... § 888.3580 Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis is a device made...

  3. 21 CFR 888.3580 - Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Knee joint patellar (hemi-knee) metallic... § 888.3580 Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis is a device made...

  4. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be...

  5. 21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be...

  6. Quasi-stiffness of the knee joint in flexion and extension during the golf swing.

    PubMed

    Choi, Ahnryul; Sim, Taeyong; Mun, Joung Hwan

    2015-01-01

    Biomechanical understanding of the knee joint during a golf swing is essential to improve performance and prevent injury. In this study, we quantified the flexion/extension angle and moment as the primary knee movement, and evaluated quasi-stiffness represented by moment-angle coupling in the knee joint. Eighteen skilled and 23 unskilled golfers participated in this study. Six infrared cameras and two force platforms were used to record a swing motion. The anatomical angle and moment were calculated from kinematic and kinetic models, and quasi-stiffness of the knee joint was determined as an instantaneous slope of moment-angle curves. The lead knee of the skilled group had decreased resistance duration compared with the unskilled group (P < 0.05), and the resistance duration of the lead knee was lower than that of the trail knee in the skilled group (P < 0.01). The lead knee of the skilled golfers had greater flexible excursion duration than the trail knee of the skilled golfers, and of both the lead and trail knees of the unskilled golfers. These results provide critical information for preventing knee injuries during a golf swing and developing rehabilitation strategies following surgery.

  7. Knee kinematics in medial osteoarthritis during in vivo weight-bearing activities.

    PubMed

    Hamai, Satoshi; Moro-oka, Taka-Aki; Miura, Hiromasa; Shimoto, Takeshi; Higaki, Hidehiko; Fregly, Benjamin J; Iwamoto, Yukihide; Banks, Scott A

    2009-12-01

    Dynamic knee kinematics were analyzed for medial osteoarthritic (OA) knees in three activities, including two types of maximum knee flexion. Continuous x-ray images of kneeling, squatting, and stair climbing motions were taken using a large flat panel detector. CT-derived bone models were used for the model registration-based 3D kinematic measurements. Three-dimensional joint kinematics and contact locations were determined using two methods: bone-fixed coordinate systems and by interrogation of CT-based bone model surfaces. The femur exhibited gradual external rotation with knee flexion for kneeling and squatting activities, and gradual internal rotation with knee extension for stair climbing. From 100 degrees to 120 degrees flexion, contact locations showed a medial pivot pattern similar to normal knees. However, knees with medial OA displayed a femoral internal rotation bias and less posterior translation when compared with normal knees. A classic screw-home movement was not observed in OA knees near extension. Decreased variability with both activities and methods of calculation were demonstrated for all three activities. In conclusion, the weight-bearing kinematics of patients with medial OA differs from normal knees. Pathological changes of the articulating surfaces and the ligaments correspond to observed abnormalities in knee kinematics.

  8. Knee Power Is an Important Parameter in Understanding Medial Knee Joint Load in Knee Osteoarthritis

    PubMed Central

    Calder, Kristina M; Acker, Stacey M; Arora, Neha; Beattie, Karen A; Callaghan, Jack P; Adachi, Jonathan D; Maly, Monica R

    2014-01-01

    Objective To determine the extent to which knee extensor strength and power explain variance in knee adduction moment (KAM) peak and impulse in clinical knee osteoarthritis (OA). Methods Fifty-three adults (mean ± SD age 61.6 ± 6.3 years, 11 men) with clinical knee OA participated. The KAM waveform was calculated from motion and force data and ensemble averaged from 5 walking trials. The KAM peak was normalized to body mass (Nm/kg). The mean KAM impulse reflected the mean total medial knee load during stride (Nm × seconds). For strength, the maximum knee extensor moment attained from maximal voluntary isometric contractions (MVIC) was normalized to body mass (Nm/kg). For power, the maximum knee extensor power during isotonic contractions, with the resistance set at 25% of MVIC, was normalized to body mass (W/kg). Covariates included age, sex, knee pain on the Knee Injury and Osteoarthritis Outcome Score, gait speed, and body mass index (BMI). Relationships of the KAM peak and impulse with strength and power were examined using sequential stepwise forward linear regressions. Results Covariates did not explain variance in the KAM peak. While extensor strength did not, peak knee extensor power explained 8% of the variance in the KAM peak (P = 0.02). Sex and BMI explained 24% of the variance in the KAM impulse (P < 0.05). Sex, BMI, and knee extensor power explained 31% of the variance in the KAM impulse (P = 0.02), with power contributing 7% (P < 0.05). Conclusion Knee extensor power was more important than isometric knee strength in understanding medial knee loads during gait. PMID:24920175

  9. Impact of pregnancy on zonisamide pharmacokinetics in rabbits.

    PubMed

    Matar, Kamal M

    2013-01-01

    Pregnancy is associated with various physiological changes which may lead to significant alterations in the pharmacokinetics of many drugs. The present study was aimed to investigate the potential effects of pregnancy on the pharmacokinetic profile of zonisamide (ZNM) in the rabbit. Seven female rabbits were used in this study. The pregnant and nonpregnant rabbits received ZNM orally at a dose of 10 mg/kg and blood samples were collected from the animals just before receiving the drug and then serially for up to 24 h. The plasma samples were analyzed using tandem mass spectrometric method. Following a single oral dose of ZNM to the rabbits, the mean values of ZNM plasma concentrations at different times were consistently low in pregnant compared to nonpregnant rabbits. The mean values of ZNM's Cmax and AUC0-∞ were significantly (P < 0.05) decreased, whereas the CL/F exhibited substantial increase (P < 0.05) in pregnant compared to nonpregnant rabbits. Tmax, t1/2abs, t1/2el, MRT, and Vd/F showed no significant differences between the two groups. The present study demonstrates that pregnancy decreased ZNM plasma concentrations in rabbits and that the decrease could be due to decreased extent of gastrointestinal absorption, induced hepatic metabolism, or enhanced renal elimination of the drug.

  10. Effects of estradiol on reduction of osteoarthritis in rabbits through effect on matrix metalloproteinase proteins

    PubMed Central

    Wang, Weiguo; Wang, Lin; Xu, Zhanwang; Yin, Yanxia; Su, Jun; Niu, Xiufeng; Cao, Xuecheng

    2016-01-01

    Objective(s): Osteoarthritis (OA), as a known degenerative joint disease, is the most common form of arthritis. In this study, we aimed to elucidate unclear pathogenesis of OA. Materials and Methods: Rabbit models of OA were established by the transection of the anterior cruciate ligament. Rabbits were randomly divided into three equal groups: the experimental group (OA modeling, treated with estradiol), the control group (OA modeling, treated with normal saline) and the normal group (without OA modeling). The glycosaminoglycan (GAG) and hyaluronan (HA) content of knee joint were collected and assayed. In addition, gene expression of matrix metalloproteinase (MMP)-1, MMP-13 and tissue inhibitor of metalloproteinase (TIMP)-1 were evaluated by real-time PCR and Western blot analysis. Results: Animal models were developed successfully. GAG and HA concentrations were significantly increased in the experimental and the normal group compared with the control group (P<0.05 and P<0.01, respectively). Significant increase of GAG level in 6, 9 and 12 week-samples were found in the experimental group compared with the control group (P<0.01). The expression level of MMP-1 and MMP-13 in the experimental group were lower than the control group (P<0.01), but still higher than those of the normal group (P<0.01). TIMP-1 expression level was found to be higher in the experimental group than that of the control and normal group (P<0.01). Conclusion: The results suggested the possible role of estradiol in the pathological process of OA via its effect on the MMPs. The results also implied the effect of estradiol intervention on OA. PMID:27114801

  11. Effect of antagonist muscle fatigue on knee extension torque.

    PubMed

    Beltman, J G M; Sargeant, A J; Ball, D; Maganaris, C N; de Haan, A

    2003-09-01

    The effect of hamstring fatigue on knee extension torque was examined at different knee angles for seven male subjects. Before and after a dynamic flexion fatigue protocol (180 degrees s(-1), until dynamic torque had declined by 50%), maximal voluntary contraction extension torque was measured at four knee flexion angles (90 degrees, 70 degrees, 50 degrees and 30 degrees ). Maximal torque generating capacity and voluntary activation of the quadriceps muscle were determined using electrical stimulation. Average rectified EMG of the biceps femoris was determined. Mean dynamic flexion torque declined by 48+/-11%. Extensor maximal voluntary contraction torque, maximal torque generating capacity, voluntary activation and average rectified EMG at the four knee angles were unaffected by the hamstring fatigue protocol. Only at 50 degrees knee angle was voluntary activation significantly lower (15.7%) after fatigue ( P<0.05). In addition, average rectified EMG before fatigue was not significantly influenced by knee angle. It was concluded that a fatigued hamstring muscle did not increase the maximal voluntary contraction extension torque and knee angle did not change coactivation. Three possible mechanisms may explain the results: a potential difference in recruited fibre populations in antagonist activity compared with the fibres which were fatigued in the protocol, a smaller loss in isometric torque generating capacity of the hamstring muscle than was expected from the dynamic measurements and/or a reduction in voluntary activation.

  12. Evaluation of a variable resistance orthotic knee joint.

    PubMed

    Herbert-Copley, Andrew; Lemaire, Edward D; Baddour, Natalie

    2016-08-01

    Knee-ankle-foot orthoses (KAFOs) are full leg braces for individuals with knee extensor weakness, designed to support the person during weight bearing activities by preventing knee flexion. KAFOs typically result in an unnatural gait pattern and are primarily used for level ground walking. A novel variable resistance orthotic knee joint, the Ottawalk-Variable Speed (OWVS), was designed to address these limitations. This paper presents a pilot test to evaluate the OWVS functional performance during walking and stair descent. A carbon-fiber KAFO was adjusted for an able-bodied participant by a certified orthotist, with a standard orthotic single axis knee joint on the medial side and the OWVS on the lateral side. The participant performed level ground walking (stance-control, open, closed) and stair descent tests. The operator was able to manually switch between closed mode in terminal swing to open mode in terminal stance for stance-control walking. Knee angle kinematics were similar between open and stance control modes. For stair descent, resistance settings supported the participant as they lowered their body to the next step, but with smaller range of motion compared to the open setting. The Ottawalk-Variable Speed design successfully controls knee flexion during stance and stair descent, with one lateral control joint. Mode switching was fast and appropriate. This microprocessor controlled SCKAFO has a low profile that fits beneath clothing and the variable resistance design will allow people to negotiate different terrain types.

  13. Trabecular metal tibial knee component still stable at 10 years.

    PubMed

    Henricson, Anders; Nilsson, Kjell G

    2016-10-01

    Background and purpose - Total knee replacement (TKR) in younger patients using cemented components has shown inferior results, mainly due to aseptic loosening. Excellent clinical results have been reported with components made of trabecular metal (TM). In a previous report, we have shown stabilization of the TM tibial implants for up to 5 years. In this study, we compared the clinical and RSA results of these uncemented implants with those of cemented implants. Patients and methods - 41 patients (47 knees) aged ≤ 60 years underwent TKR. 22 patients (26 knees) received an uncemented monoblock cruciate-retaining (CR) tibial component (TM) and 19 patients (21 knees) received a cemented NexGen Option CR tibial component. Follow-up examination was done at 10 years, and 16 patients (19 knees) with TM tibial components and 17 patients (18 knees) with cemented tibial components remained for analysis. Results - 1 of 19 TM implants was revised for infection, 2 of 18 cemented components were revised for knee instability, and no revisions were done for loosening. Both types of tibial components migrated in the first 3 months, the TM group to a greater extent than the cemented group. After 3 months, both groups were stable during the next 10 years. Interpretation - The patterns of migration for uncemented TM implants and cemented tibial implants over the first 10 years indicate that they have a good long-term prognosis regarding fixation.

  14. Trabecular metal tibial knee component still stable at 10 years

    PubMed Central

    Henricson, Anders; Nilsson, Kjell G

    2016-01-01

    Background and purpose Total knee replacement (TKR) in younger patients using cemented components has shown inferior results, mainly due to aseptic loosening. Excellent clinical results have been reported with components made of trabecular metal (TM). In a previous report, we have shown stabilization of the TM tibial implants for up to 5 years. In this study, we compared the clinical and RSA results of these uncemented implants with those of cemented implants. Patients and methods 41 patients (47 knees) aged ≤ 60 years underwent TKR. 22 patients (26 knees) received an uncemented monoblock cruciate-retaining (CR) tibial component (TM) and 19 patients (21 knees) received a cemented NexGen Option CR tibial component. Follow-up examination was done at 10 years, and 16 patients (19 knees) with TM tibial components and 17 patients (18 knees) with cemented tibial components remained for analysis. Results 1 of 19 TM implants was revised for infection, 2 of 18 cemented components were revised for knee instability, and no revisions were done for loosening. Both types of tibial components migrated in the first 3 months, the TM group to a greater extent than the cemented group. After 3 months, both groups were stable during the next 10 years. Interpretation The patterns of migration for uncemented TM implants and cemented tibial implants over the first 10 years indicate that they have a good long-term prognosis regarding fixation PMID:27357222

  15. Chronic knee extensor mechanism lesions in total knee arthroplasty: a literature review

    PubMed Central

    COTTINO, UMBERTO; DELEDDA, DAVIDE; ROSSO, FEDERICA; BLONNA, DAVIDE; BONASIA, DAVIDE EDOARDO; ROSSI, ROBERTO

    2016-01-01

    Knee extensor mechanism rupture is a serious complication of total knee arthroplasty (TKA). Its prevalence ranges from 1 to 10% and it is commonly observed as a chronic multifactorial pathology with the patellar tendon as the most common site of rupture. Knee extensor mechanism reconstruction can be performed using allogenic or synthetic grafts. In the literature it is still not clear whether one of these techniques is superior to the other and the choice is usually tailored to the patient case by case. Allografts allow better restoration of the anatomical landmarks, whereas the mesh technique is more reproducible and the graft does not elongate over time. Allografts carry an increased risk of infection compared with synthetic reconstructions, while the mesh technique is cheaper and more readily available. In this paper, we review the etiology, diagnosis and treatment of this pathology, drawing on the most recent literature. PMID:27900308

  16. AMECM/DCB scaffold prompts successful total meniscus reconstruction in a rabbit total meniscectomy model.

    PubMed

    Yuan, Zhiguo; Liu, Shuyun; Hao, Chunxiang; Guo, Weimin; Gao, Shuang; Wang, Mingjie; Chen, Mingxue; Sun, Zhen; Xu, Yichi; Wang, Yu; Peng, Jiang; Yuan, Mei; Guo, Quan-Yi

    2016-12-01

    Tissue-engineered meniscus regeneration is a very promising treatment strategy for meniscus lesions. However, generating the scaffold presents a huge challenge for meniscus engineering as this has to meet particular biomechanical and biocompatibility requirements. In this study, we utilized acellular meniscus extracellular matrix (AMECM) and demineralized cancellous bone (DCB) to construct three different types of three-dimensional porous meniscus scaffold: AMECM, DCB, and AMECM/DCB, respectively. We tested the scaffolds' physicochemical characteristics and observed their interactions with meniscus fibrochondrocytes to evaluate their cytocompatibility. We implanted the three different types of scaffold into the medial knee menisci of New Zealand rabbits that had undergone total meniscectomy; negative control rabbits received no implants. The reconstructed menisci and corresponding femoral condyle and tibial plateau cartilage were all evaluated at 3 and 6 months (n = 8). The in vitro study demonstrated that the AMECM/DCB scaffold had the most suitable biomechanical properties, as this produced the greatest compressive and tensile strength scores. The AMECM/DCB and AMECM scaffolds facilitated fibrochondrocyte proliferation and the secretion of collagen and glycosaminoglycans (GAGs) more effectively than did the DCB scaffold. The in vivo experiments demonstrated that both the AMECM/DCB and DCB groups had generated neomeniscus at both 3 and 6 months post-implantation, but there was no obvious meniscus regeneration in the AMECM or control groups, so the neomeniscus analysis could not perform on AMECM and control group. At both 3 and 6 months, histological scores were better for regenerated menisci in the AMECM/DCB than in the DCB group, and significantly better for articular cartilage in the AMECM/DCB group compared with the other three groups. Knee MRI scores (Whole-Organ Magnetic Resonance Imaging Scores (WORMS)) were better in the AMECM/DCB group than in the

  17. From rabbit antibody repertoires to rabbit monoclonal antibodies

    PubMed Central

    Weber, Justus; Peng, Haiyong; Rader, Christoph

    2017-01-01

    In this review, we explain why and how rabbit monoclonal antibodies have become outstanding reagents for laboratory research and increasingly for diagnostic and therapeutic applications. Starting with the unique ontogeny of rabbit B cells that affords highly distinctive antibody repertoires rich in in vivo pruned binders of high diversity, affinity and specificity, we describe the generation of rabbit monoclonal antibodies by hybridoma technology, phage display and alternative methods, along with an account of successful humanization strategies. PMID:28336958

  18. Management of the Swollen Knee

    PubMed Central

    Stanish, William D.; Rice, William; Ratson, Gary; Loebenberg, Mark; Langley, Linda

    1988-01-01

    The primary-care physician plays a critical role in the diagnosis, initial treatment, and subsequent rehabilitation of many orthopedic conditions. The knee is the most frequently injured joint in sport medicine. The family physician must therefore be familiar with the etiology, cause, and natural history of problems related to the knee joint. The swollen knee is one of the most common ailments the family physician is asked to assess in his or her busy day-to-day practice of medicine. He or she must therefore remain abreast of the dynamic field of diagnostic procedures, treatments, and rehabilitative measures relating to many knee injuries. This paper deals with the more common causes of the acutely swollen knee, paying particular attention to the infected knee and the acute hemarthrosis. It should provide answers to most questions about diagnosis, initial treatment, and subsequent management of this problem. PMID:21264033

  19. Protease inhibitors decrease rabbit cartilage degradation after meniscectomy

    SciTech Connect

    Caputo, C.B.; Sygowski, L.A.; Patton, S.P.; Wolanin, D.J.; Shaw, A.; Roberts, R.A.; DiPasquale, G.

    1988-01-01

    In vitro proteoglycan (PG) synthesis and release were measured on cartilage removed from rabbit knees within 1 week of meniscectomy. Three days following partial lateral meniscectomy, 72% of the femurs and 82% of the tibias had visible ulcers. Cartilage from the weight-bearing areas incorporated 2.0-2.9 times more /sup 35/S-sulfate in vitro than cartilage from the opposite, unoperated knees. /sup 3/H-thymidine incorporation was 2.5-3.4 times higher for surgical than control groups. /sup 35/S-sulfate incorporation by the surgical group was inhibited by 22% in the presence of 10(-4) M U24522, an inhibitor of rabbit chondrocyte metalloprotease (CMP). /sup 3/H-thymidine incorporation by the surgical group was inhibited by 28% by 10(-4) M U24522. In vitro PG release from cartilage removed 2 days after surgery was 1.6-3.7 times higher for the surgical than the control group. PG release by the surgical group after 22 h of incubation was reduced to the control level by three CMP inhibitors, U24278, U24279, and U24522. PG release by cartilage from the nonsurgical group was also reduced by these compounds at 22 h. These results suggest that both the anabolic and catabolic processes that are stimulated by surgery can be isolated in vitro and that CMP may be involved in the catabolic process.

  20. Effect of Mulligan's and Kinesio knee taping on adolescent ballet dancers knee and hip biomechanics during landing.

    PubMed

    Hendry, D; Campbell, A; Ng, L; Grisbrook, T L; Hopper, D M

    2015-12-01

    Taping is often used to manage the high rate of knee injuries in ballet dancers; however, little is known about the effect of taping on lower-limb biomechanics during ballet landings in the turnout position. This study investigated the effects of Kinesiotape (KT), Mulligan's tape (MT) and no tape (NT) on knee and hip kinetics during landing in three turnout positions. The effect of taping on the esthetic execution of ballet jumps was also assessed. Eighteen pain-free 12-15-year-old female ballet dancers performed ballet jumps in three turnout positions, under the three knee taping conditions. A Vicon Motion Analysis system (Vicon Oxford, Oxford, UK) and Advanced Mechanical Technology, Inc. (Watertown, Massa chusetts, USA) force plate collected lower-limb mechanics. The results demonstrated that MT significantly reduced peak posterior knee shear forces (P = 0.025) and peak posterior (P = 0.005), medial (P = 0.022) and lateral (P = 0.014) hip shear forces compared with NT when landing in first position. KT had no effect on knee or hip forces. No significant differences existed between taping conditions in all landing positions for the esthetic measures. MT was able to reduce knee and the hip forces without affecting the esthetic performance of ballet jumps, which may have implications for preventing and managing knee injuries in ballet dancers.

  1. Validation of a novel smartphone accelerometer-based knee goniometer.

    PubMed

    Ockendon, Matthew; Gilbert, Robin E

    2012-09-01

    Loss of full knee extension following anterior cruciate ligament surgery has been shown to impair knee function. However, there can be significant difficulties in accurately and reproducibly measuring a fixed flexion of the knee. We studied the interobserver and the intraobserver reliabilities of a novel, smartphone accelerometer-based, knee goniometer and compared it with a long-armed conventional goniometer for the assessment of fixed flexion knee deformity. Five healthy male volunteers (age range 30 to 40 years) were studied. Measurements of knee flexion angle were made with a telescopic-armed goniometer (Lafayette Instrument, Lafayette, IN) and compared with measurements using the smartphone (iPhone 3GS, Apple Inc., Cupertino, CA) knee goniometer using a novel trigonometric technique based on tibial inclination. Bland-Altman analysis of validity and reliability including statistical analysis of correlation by Pearson's method was undertaken. The iPhone goniometer had an interobserver correlation (r) of 0.994 compared with 0.952 for the Lafayette. The intraobserver correlation was r = 0.982 for the iPhone (compared with 0.927). The datasets from the two instruments correlate closely (r = 0.947) are proportional and have mean difference of only -0.4 degrees (SD 3.86 degrees). The Lafayette goniometer had an intraobserver reliability +/- 9.6 degrees. The interobserver reliability was +/- 8.4 degrees. By comparison the iPhone had an interobserver reliability +/- 2.7 degrees and an intraobserver reliability +/- 4.6 degrees. We found the iPhone goniometer to be a reliable tool for the measurement of subtle knee flexion in the clinic setting.

  2. Human adipose-derived mesenchymal progenitor cells engraft into rabbit articular cartilage.

    PubMed

    Wang, Wen; He, Na; Feng, Chenchen; Liu, Victor; Zhang, Luyi; Wang, Fei; He, Jiaping; Zhu, Tengfang; Wang, Shuyang; Qiao, Weiwei; Li, Suke; Zhou, Guangdong; Zhang, Li; Dai, Chengxiang; Cao, Wei

    2015-05-27

    Mesenchymal stem cells (MSCs) are known to have the potential for articular cartilage regeneration, and are suggested for the treatment of osteoarthritis (OA). Here, we investigated whether intra-articular injection of xenogeneic human adipose-derived mesenchymal progenitor cells (haMPCs) promoted articular cartilage repair in rabbit OA model and engrafted into rabbit articular cartilage. The haMPCs were cultured in vitro, and phenotypes and differentiation characteristics of cells were evaluated. OA was induced surgically by anterior cruciate ligament transection (ACLT) and medical meniscectomy of knee joints. At six weeks following surgery, hyaluronic acid (HA) or haMPCs was injected into the knee joints, the contralateral knee served as normal control. All animals were sacrificed at the 16th week post-surgery. Assessments were carried out by macroscopic examination, hematoxylin/eosin (HE) and Safranin-O/Fast green stainings and immunohistochemistry. The data showed that haMPC treatment promoted cartilage repair. Signals of human mitochondrial can be directly detected in haMPC treated cartilage. The haMPCs expressed human leukocyte antigen I (HLA-I) but not HLA-II-DR in vivo. These results suggest that intra-articular injection of haMPCs promotes regeneration of articular cartilage in rabbit OA model, and support the notion that MPCs are transplantable between HLA-incompatible individuals.

  3. Rabbit models for the study of human atherosclerosis: from pathophysiological mechanisms to translational medicine.

    PubMed

    Fan, Jianglin; Kitajima, Shuji; Watanabe, Teruo; Xu, Jie; Zhang, Jifeng; Liu, Enqi; Chen, Y Eugene

    2015-02-01

    Laboratory animal models play an important role in the study of human diseases. Using appropriate animals is critical not only for basic research but also for the development of therapeutics and diagnostic tools. Rabbits are widely used for the study of human atherosclerosis. Because rabbits have a unique feature of lipoprotein metabolism (like humans but unlike rodents) and are sensitive to a cholesterol diet, rabbit models have not only provided many insights into the pathogenesis and development of human atherosclerosis but also made a great contribution to translational research. In fact, rabbit was the first animal model used for studying human atherosclerosis, more than a century ago. Currently, three types of rabbit model are commonly used for the study of human atherosclerosis and lipid metabolism: (1) cholesterol-fed rabbits, (2) Watanabe heritable hyperlipidemic rabbits, analogous to human familial hypercholesterolemia due to genetic deficiency of LDL receptors, and (3) genetically modified (transgenic and knock-out) rabbits. Despite their importance, compared with the mouse, the most widely used laboratory animal model nowadays, the use of rabbit models is still limited. In this review, we focus on the features of rabbit lipoprotein metabolism and pathology of atherosclerotic lesions that make it the optimal model for human atherosclerotic disease, especially for the translational medicine. For the sake of clarity, the review is not an attempt to be completely inclusive, but instead attempts to summarize substantial information concisely and provide a guideline for experiments using rabbits.

  4. Molecular identification and phylogenesis of dermatophytes isolated from rabbit farms and rabbit farm workers.

    PubMed

    Cafarchia, Claudia; Weigl, Stefania; Figueredo, Luciana A; Otranto, Domenico

    2012-01-27

    Little information is available on the molecular epidemiology of dermatophytoses in rabbit farms and farm workers. A total of 117 isolates belonging to the Trichophyton mentagrophytes complex and 21 isolates of Microsporum canis were collected from rabbits with or without skin lesions, air samples of farms known to harbour these pathogens, and from farm workers with skin lesions, and molecularly characterized. Sequencing of amplicons from the T. mentagrophytes complex and M. canis isolates revealed the presence of one sequence-type for both partial chitin synthase-1 gene (pchs-1) and ribosomal internal transcribed spacer (ITS+), respectively. On the basis of comparative sequence analyses, isolated representing the T. mentagrophytes complex were molecularly identified as Trichophyton interdigitale (zoophilic) Priestley. The M. canis and T. interdigitale pchs-1 sequences herein analysed were 100% homologous to known sequences from different hosts (i.e., cats, dogs, humans and rabbits). Conversely, the ITS+ sequences of T. interdigitale from dogs, pigs and mice were identical, but displayed up to 8.6% difference with those from humans, guinea pigs and rabbits. The results of this study suggest that environmental and clinical isolates of T. interdigitale (zoophilic) and M. canis might share a common origin. Interestingly, the close phylogenetic relationship between T. interdigitale (zoophilic) strains and isolates from dogs, pigs and mice might indicate that these animals represented a reservoir of dermatophyte infection in rabbit farms. These animal species should therefore be considered when setting up control protocols to prevent infections by dermatophytes and their zoonotic transmission.

  5. Unmet Needs and Waiting List Prioritization for Knee Arthroplasty

    PubMed Central

    Comas, Mercè; Román, Rubén; Quintana, José Maria

    2009-01-01

    Background There is a high volume of unmet needs for knee arthroplasty in the population despite the increase in surgery rates. Given the long waiting times to have a knee arthroplasty, some governments have proposed prioritization systems for patients on waiting lists based on their level of need. Questions/Purposes We therefore estimated the needs and demand of knee arthroplasty in four regions of Spain during a 5-year period. Methods We developed a discrete event simulation model to reproduce the process of knee arthroplasty. The prioritization system was compared with the usual waiting list management strategy (by waiting time only). Results Under the prioritization system, patients saved an average of 4.5 months (95% confidence interval, 4.4–4.6 months) adjusted by level of need. The proportion of patients who experienced excessive waiting times was small and was associated with low levels of priority. The 5-year projection of the volume of unmet needs for knee arthroplasty remained stable; however, although the volume of need for the first knee arthroplasty decreased by 12%, the volume of need for an arthroplasty in the contralateral knee increased by 50%. Conclusions The data suggested the prioritization system was more beneficial than assigning surgery by waiting time only. The 5-year projection of the volume of unmet needs for knee arthroplasty remained stable, despite the increase in the need for contralateral knee arthroplasty. Level of Evidence Level II, economic and decision analyses. See Guidelines for Authors for a complete description of levels of evidence. PMID:19911242

  6. Knee joint kinematics, fixation and function related to joint area design in total knee arthroplasty.

    PubMed

    Uvehammer, J

    2001-02-01

    The aim was to study the influence of different designs of the joint area on tibial component fixation, kinematics and clinical outcome after a cemented total knee arthroplasty (TKA). The HSS score and a special questionnaire were used at the clinical examination. Conventional radiography was done to record the positioning of the implants and development of radiolucencies. The migration and inducible displacement were evaluated using radiostereometry (RSA). The kinematics of the knee during active extension was studied using dynamic RSA. In randomised and prospective studies 87 knees in 83 patients (28 male, 55 female, age 69, range 50-83) received an AMK (DePuy, Johnson & Johnson) TKA. The patients were divided into two groups. In group 1 the patients had varus/valgus deformities of < or = 5 degrees and the PCL was retained. The PCL was resected in group 2 where the patients had deformities exceeding 5 degrees and/or fixed flexion deformities of more than 10 degrees. In group 1 a flat (F, n = 20) or a concave (C, n = 20) design was implanted (study 3). In group 2 (study 4) the patients received a concave (n = 25) or a posterior-stabilised (PS, n = 22) tibial plateau. The migration of the tibial component, positioning of the prosthesis, development of radiolucencies and the clinical outcome was evaluated after 1 and 2 years. Twenty-two patients (11 F, 11 C) in group 1 (study 1) and 22 knees in 20 patients in group 2 (study 2, 11 C, 11 PS) were examined 1 year post-operatively to evaluate the kinematics of the knee. Eleven normals served as controls. During active extension of the knee the inducible displacements of the tibial component were recorded in 16 knees (15 patients). Based on successful RSA examinations 5 knees (4 F, 1 C) from group 1 and 11 knees (5 C, 6 PS) from group 2 were selected (study 5). Abnormal kinematics and especially increased AP translations compared to normals (p < 0.0005) were recorded in all designs. The concave design showed the widest

  7. Rabbits killing birds revisited.

    PubMed

    Zhang, Jimin; Fan, Meng; Kuang, Yang

    2006-09-01

    We formulate and study a three-species population model consisting of an endemic prey (bird), an alien prey (rabbit) and an alien predator (cat). Our model overcomes several model construction problems in existing models. Moreover, our model generates richer, more reasonable and realistic dynamics. We explore the possible control strategies to save or restore the bird by controlling or eliminating the rabbit or the cat when the bird is endangered. We confirm the existence of the hyperpredation phenomenon, which is a big potential threat to most endemic prey. Specifically, we show that, in an endemic prey-alien prey-alien predator system, eradication of introduced predators such as the cat alone is not always the best solution to protect endemic insular prey since predator control may fail to protect the indigenous prey when the control of the introduced prey is not carried out simultaneously.

  8. Selectively lockable knee brace

    NASA Technical Reports Server (NTRS)

    Myers, Neill (Inventor); Shadoan, Mike (Inventor); Forbes, John (Inventor); Baker, Kevin (Inventor)

    1994-01-01

    A knee brace for aiding in rehabilitation of damaged leg muscles includes upper and lower housings, normally pivotable, one relative to the other about the knee joint axis of a patient. The upper housing is attachable to the thigh of the patient above the knee joint, while the lower housing is secured to a stirrup which extends downwardly along the patient's leg and is attached to the patient's shoe. An actuation rod is carried within the lower housing and is coupled to a cable. The upper and lower housings carry cooperative clutch/brake elements which normally are disengaged to permit relative movement between the upper and lower housings. When the cable is extended, the clutch/brake elements engage and lock the housings together. A heel strike mechanism fastened to the stirrup and the heel of the shoe is connected to the cable to selectively extend the cable and lock the brace in substantially any position when the patient places weight on the heel.

  9. Selectively Lockable Knee Brace

    NASA Technical Reports Server (NTRS)

    Myers, W. Neill (Inventor); Shadoan, Michael D. (Inventor); Forbes, John C. (Inventor); Baker, Kevin J. (Inventor); Rice, Darron C. (Inventor)

    1996-01-01

    A knee brace for aiding in rehabilitation of damaged leg muscles includes upper and lower housings normally pivotable one relative to the other about the knee joint axis of a patient. The upper housing is attachable to the thigh of the patient above the knee joint while the lower housing is secured to a stirrup which extends downwardly along the patient's leg and is attached to the patient's shoe. An actuation rod is carried within the lower housing and is coupled to a cable. The upper and lower housings carry cooperative clutch/brake elements which normally are disengaged to permit relative movement between the upper and lower housings. When the cable is extended the clutch/brake elements engage and lock the housings together. A heel strike mechanism fastened to the stirrup and the heel of the shoe is connected to the cable to selectively extend the cable and lock the brace in substantially any position when the patient places weight on the heel.

  10. [Physical activity for knee osteoarthritis.

    PubMed

    Nagao, Masashi; Ishijima, Muneaki; Kaneko, Haruka; Takazawa, Yuji; Ikeda, Hiroshi; Kaneko, Kazuo

    Elder populations have been increasing in Japan and estimated 24 million people have knee osteoarthritis(OA). Recently, people have diverse sociological background and demand for participating sports has been growing. People may participate sports to prevent some diseases such as locomotive syndrome. According to the recent studies, excessive high impact sports increase the risk of OA, while daily life exercise decrease the risk. Epidemiological approach demonstrated that reduced knee extension muscle strength increases the risk of OA. We reviewed and discussed the recent topics including efficacy of physical therapy for knee OA and how much sports activities could be beneficial after knee surgery.

  11. Knee stabilization in patients with medial compartment knee osteoarthritis

    PubMed Central

    Lewek, Michael D.; Ramsey, Dan K.; Snyder-Mackler, Lynn; Rudolph, Katherine S.

    2005-01-01

    OBJECTIVE Individuals with medial knee osteoarthritis (MKOA) experience knee laxity and instability. Muscle stabilization strategies may influence the long term integrity of the joint. In this study we determined how individuals with medial knee OA respond to a rapid valgus knee movement to investigate the relationship between muscle stabilization strategies and knee instability. METHODS Twenty one subjects with MKOA and genu varum, and 19 control subjects were tested. Subjects stood with the test limb on a moveable platform that translated laterally to rapidly stress the knee’s medial periarticular structures and create a potentially destabilizing feeling at the knee joint. Knee motion and muscle responses were recorded. Subjects rated their knee instability with a self-report questionnaire about knee instability during daily activities. RESULTS Prior to plate movement the OA subjects demonstrated more medial muscle co-contraction (p=0.014). Following plate movement the OA subjects shifted less weight off the test limb (p = 0.013) and had more medial co-contraction (p=0.037). Those without instability had higher VMMH co-contraction than those who reported more instability (p=0.038). Knee stability correlated positively with VMMH co-contraction prior to plate movement (r = 0.459; p = 0.042). CONCLUSION This study demonstrates that individuals with MKOA attempt to stabilize the knee with greater medial muscle co-contraction in response to laxity that appears on only the medial side of the joint. This strategy presumably contributes to higher joint compression and could exacerbate joint destruction and needs to be altered to slow or stop the progression of the OA disease process. PMID:16142714

  12. Gait patterns during different walking conditions in older adults with and without knee osteoarthritis--results from the Baltimore Longitudinal Study of Aging.

    PubMed

    Ko, Seung-uk; Ling, Shari M; Schreiber, Catherine; Nesbitt, Mark; Ferrucci, Luigi

    2011-02-01

    Biomechanical analysis of lower extremity activities while walking at different speeds and in challenging conditions may help to identify specific gait patterns associated with knee osteoarthritis (knee-OA). We hypothesized that individuals with asymptomatic knee-OA have lower ankle activity, while individuals with symptomatic knee-OA have similar or higher ankle activity compared to individuals without knee-OA, and that such differences are enhanced during challenging gait tasks. We tested this hypothesis by examining gait characteristics in multiple gait tasks using data from 153 Baltimore Longitudinal Study of Aging (BLSA) participants (112 without knee-OA, 41 with knee-OA; 53-87 years, 52% women). All participants who could walk unassisted were evaluated in the BLSA gait lab while walking at self-selected speed (usual-walking), at maximum speed (fast-walking) and again at self-selected speed after 30-min of walking activities (usual-walking-after-30 min). Knee range of motion was lower for knee-OA participants in the fast-walking and usual-walking-after-30 min tasks (p<0.030). Ankle range of motion for symptomatic knee-OA was greater compared to asymptomatic knee-OA for all walking tasks (p<0.050). Symptomatic knee-OA had greater generative MWE of the ankle compared to asymptomatic knee-OA (p=0.034), while keeping similar absorptive MWE of the knee when compared to no-OA controls (p=0.151). Symptomatic knee-OA individuals seem to adapt an ankle kinematic gait pattern aimed at avoiding knee pain, by enhancing forward propulsion so to minimize knee joint load. Whether these conditions represent subsequent steps in the causal pathway from knee-OA to changes in gait is still not clear.

  13. Ceftaroline-Fosamil Efficacy against Methicillin-Resistant Staphylococcus aureus in a Rabbit Prosthetic Joint Infection Model

    PubMed Central

    Gatin, Laure; Saleh-Mghir, Azzam; Tasse, Jason; Ghout, Idir; Laurent, Frédéric

    2014-01-01

    Ceftaroline (CPT), the active metabolite of the prodrug ceftaroline-fosamil (CPT-F), demonstrates in vitro bactericidal activity against methicillin-resistant Staphylococcus aureus (MRSA) and is effective in rabbit models of difficult-to-treat MRSA endocarditis and acute osteomyelitis. However, its in vivo efficacy in a prosthetic joint infection (PJI) model is unknown. Using a MRSA-infected knee PJI model in rabbits, the efficacies of CPT-F or vancomycin (VAN) alone and combined with rifampin (RIF) were compared. After each partial knee replacement with a silicone implant that fit into the tibial intramedullary canal was performed, 5 × 107 MRSA CFU (MICs of 0.38, 0.006, and 1 mg/liter for CPT, RIF, and VAN, respectively) was injected into the knee. Infected animals were randomly assigned to receive no treatment (controls) or CPT-F (60 mg/kg of body weight intramuscularly [i.m.]), VAN (60 mg/kg i.m.), CPT-F plus RIF (10 mg/kg i.m.), or VAN plus RIF starting 7 days postinoculation and lasting for 7 days. Surviving bacteria in crushed tibias were counted 3 days after ending treatment. Although the in vivo mean log10 CFU/g of CPT-treated (3.0 ± 0.9, n = 12) and VAN-treated (3.5 ± 1.1, n = 12) crushed bones was significantly lower than those of controls (5.6 ± 1.1, n = 14) (P < 0.001), neither treatment fully sterilized the bones (3/12 were sterile with each treatment). The mean log10 CFU/g values for the antibiotics in combination with RIF were 1.9 ± 0.5 (12/14 were sterile) for CPT-F and 1.9 ± 0.5 (12/14 were sterile) for VAN. In this MRSA PJI model, the efficacies of CPT-F and VAN did not differ; thus, CPT appears to be a promising antimicrobial agent for the treatment of MRSA PJIs. PMID:25136014

  14. Ceftaroline-Fosamil efficacy against methicillin-resistant Staphylococcus aureus in a rabbit prosthetic joint infection model.

    PubMed

    Gatin, Laure; Saleh-Mghir, Azzam; Tasse, Jason; Ghout, Idir; Laurent, Frédéric; Crémieux, Anne-Claude

    2014-11-01

    Ceftaroline (CPT), the active metabolite of the prodrug ceftaroline-fosamil (CPT-F), demonstrates in vitro bactericidal activity against methicillin-resistant Staphylococcus aureus (MRSA) and is effective in rabbit models of difficult-to-treat MRSA endocarditis and acute osteomyelitis. However, its in vivo efficacy in a prosthetic joint infection (PJI) model is unknown. Using a MRSA-infected knee PJI model in rabbits, the efficacies of CPT-F or vancomycin (VAN) alone and combined with rifampin (RIF) were compared. After each partial knee replacement with a silicone implant that fit into the tibial intramedullary canal was performed, 5 × 10(7) MRSA CFU (MICs of 0.38, 0.006, and 1 mg/liter for CPT, RIF, and VAN, respectively) was injected into the knee. Infected animals were randomly assigned to receive no treatment (controls) or CPT-F (60 mg/kg of body weight intramuscularly [i.m.]), VAN (60 mg/kg i.m.), CPT-F plus RIF (10 mg/kg i.m.), or VAN plus RIF starting 7 days postinoculation and lasting for 7 days. Surviving bacteria in crushed tibias were counted 3 days after ending treatment. Although the in vivo mean log10 CFU/g of CPT-treated (3.0 ± 0.9, n = 12) and VAN-treated (3.5 ± 1.1, n = 12) crushed bones was significantly lower than those of controls (5.6 ± 1.1, n = 14) (P < 0.001), neither treatment fully sterilized the bones (3/12 were sterile with each treatment). The mean log10 CFU/g values for the antibiotics in combination with RIF were 1.9 ± 0.5 (12/14 were sterile) for CPT-F and 1.9 ± 0.5 (12/14 were sterile) for VAN. In this MRSA PJI model, the efficacies of CPT-F and VAN did not differ; thus, CPT appears to be a promising antimicrobial agent for the treatment of MRSA PJIs.

  15. Development of a knee joint motion simulator to evaluate deep knee flexion of artificial knee joints.

    PubMed

    Takano, Y; Ueno, M; Kiguchi, K; Ito, J; Mawatari, M; Hotokebuchi, T

    2008-01-01

    A purpose of this study is to examine the effect that quadriceps femoris force gives to rotation angle and joint reaction force of total knee prosthesis during deep knee flexion such as a unique sitting style called 'seiza' in Japanese. For the evaluation, we developed the knee motion simulator which could bend to 180 degrees continually simulating the passive flexion performed by clinicians. A total knee prosthesis, which is a specially-devised posterior stabilized type and capable of flexion up to 180 degrees, was inserted into bone model. And this prosthesis pulled by three kinds of quadriceps femoris forces to perform parameter study. The results obtained in this study were showed the same tendency with those in the past cadaveric experiment. It is suggested that the rotation angle and joint reaction force of total knee prosthesis are affected by shape of prosthesis, a vector of quadriceps femoris force, and bony aliments during deep knee flexion.

  16. Gait variability and motor control in people with knee osteoarthritis.

    PubMed

    Alkjaer, Tine; Raffalt, Peter C; Dalsgaard, Helle; Simonsen, Erik B; Petersen, Nicolas C; Bliddal, Henning; Henriksen, Marius

    2015-10-01

    Knee osteoarthritis (OA) is a common disease that impairs walking ability and function. We compared the temporal gait variability and motor control in people with knee OA with healthy controls. The purpose was to test the hypothesis that the temporal gait variability would reflect a more stereotypic pattern in people with knee OA compared with healthy age-matched subjects. To assess the gait variability the temporal structure of the ankle and knee joint kinematics was quantified by the largest Lyapunov exponent and the stride time fluctuations were quantified by sample entropy and detrended fluctuation analysis. The motor control was assessed by the soleus (SO) Hoffmann (H)-reflex modulation and muscle co-activation during walking. The results showed no statistically significant mean group differences in any of the gait variability measures or muscle co-activation levels. The SO H-reflex amplitude was significantly higher in the knee OA group around heel strike when compared with the controls. The mean group difference in the H-reflex in the initial part of the stance phase (control-knee OA) was -6.6% Mmax (95% CI: -10.4 to -2.7, p=0.041). The present OA group reported relatively small impact of their disease. These results suggest that the OA group in general sustained a normal gait pattern with natural variability but with suggestions of facilitated SO H-reflex in the swing to stance phase transition. We speculate that the difference in SO H-reflex modulation reflects that the OA group increased the excitability of the soleus stretch reflex as a preparatory mechanism to avoid sudden collapse of the knee joint which is not uncommon in knee OA.

  17. Measured flexion following total knee arthroplasty.

    PubMed

    Mai, Kenny T; Verioti, Christopher A; Hardwick, Mary E; Ezzet, Kace A; Copp, Steven N; Colwell, Clifford W

    2012-10-01

    Postoperative flexion is an important factor in the outcome of total knee arthroplasty. Although normal activities of daily living require a minimum of 105° to 110° of flexion, patients from non-Western cultures often engage in activities such as kneeling and squatting that require higher flexion. The desire to achieve greater flexion serves as the driving force for prosthetic modifications, including high-flexion designs. Techniques used to measure knee flexion and knee position during measurement are not often described or are different depending on the examiner. The purpose of this study was to compare active (self) and passive (assisted) flexion after successful total knee arthroplasty for 5 prostheses (2 standard and 3 high-flexion) using clinical (goniometer) and radiographic (true lateral radiograph) measurement techniques by different independent examiners.At a mean follow-up of 2.7 years (range, 1-5.6 years), a total of 108 patients (144 total knee arthroplasties) had completed the study. Mean postoperative active flexion was 111° clinically and 109° radiographically for the standard designs and 114° clinically and 117° radiographically for the high-flexion designs. Adding passive flexion increased flexion to 115° clinically and 117° radiographically for the standard designs and 119° clinically and 124° radiographically for the high-flexion designs. Flexion differences between the 2 measurement techniques (active vs passive and clinically vs radiographically) were statistically significant (P<.05). These findings demonstrate the importance of describing how flexion is measured in studies and understanding how the method of measurement can affect the findings.

  18. Influence of offset stem couplers in femoral revision knee arthroplasty: a radiographic study.

    PubMed

    Brilhault, Jean M; Ries, Michael D

    2012-03-01

    We questioned whether the use of offset femoral stem would result in modifying the posterior femoral condylar offset (PFCO) in revision knee arthroplasty (RTKA). We measured both PFCO and stem alignment on lateral radiographs of two cohorts: 91 knees with straight stems and 35 knees with offset coupled stems. A higher PCOR was observed in knees with an offset stem compared to knees with straight stem. Knees with an offset stem had a better alignment within the intramedullary canal. Our conclusion is that the use of a modular offset coupler with femoral stem in RTKA compared to a modular straight stem both increases the posterior condylar offset and improves alignment of the stem within the intramedullary canal.

  19. Anatomic Versus Mechanically Aligned Total Knee Arthroplasty for Unicompartmental Knee Arthroplasty Revision

    PubMed Central

    Toliopoulos, Panagiota; LeBlanc, Marc-Andre; Hutt, Jonathan; Lavigne, Martin; Desmeules, Francois; Vendittoli, Pascal-Andre

    2016-01-01

    Objectives: The purpose of this study was to compare the intra-operative benefits and the clinical outcomes from kinematic or mechanical alignment for total knee arthroplasty (TKA) in patients undergoing revision of failed unicompartmental kneel arthroplasty (UKA) to TKA. Methods: Ten revisions were performed with a kinematic alignment technique and 11 with a mechanical alignment. Measurements of the hip-knee-ankle angle (HKA), the lateral distal femoral angle (LDFA), and the medial proximal tibial angle (MPTA) were performed using long-leg radiographs. The need for augments, stems, and constrained inserts was compared between groups. Clinical outcomes were compared using the WOMAC score along with maximum distance walked as well as knee range of motion obtained prior to discharge. All data was obtained by a retrospective review of patient files. Results: The kinematic group required less augments, stems, and constrained inserts than the mechanical group and thinner polyethylene bearings. There were significant differences in the lateral distal femoral angle (LDFA) and the medial proximal tibial angle (MPTA) between the two groups (p<0.05). The mean WOMAC score obtained at discharge was better in the kinematic group as was mean knee flexion. At last follow up of 34 months for the kinematic group and 58 months for the mechanical group, no orthopedic complications or reoperations were recorded. Conclusion: Although this study has a small patient cohort, our results suggest that kinematic alignment for TKA after UKA revision is an attractive method. Further studies are warranted. PMID:27563365

  20. Medial pivot knee in primary total knee arthroplasty.

    PubMed

    Atzori, Francesco; Salama, Wael; Sabatini, Luigi; Mousa, Shazly; Khalefa, Abdelrahman

    2016-01-01

    Total knee arthroplasty (TKA) with a medial pivot design was developed in order to mimic normal knee kinematics; the highly congruent medial compartment implant should improve clinical results and decrease contact stresses. Clinical and radiographic mid-term outcomes are satisfactory, but we need other studies to evaluate long-term results and indications for unusual cases.

  1. Should the patella be replaced in total knee replacement?

    PubMed

    Badhe, N; Dewnany, G; Livesley, P J

    2001-01-01

    In 170 total knee arthroplasties for osteoarthritis 71 did not receive a patellar replacement (group A), while 99 knees had a cemented polyethylene patella (group B). The mean follow-up time was 36 months (30-50 months). In group A 10 patients underwent second-stage patellar resurfacing and in group B 2 knees underwent revision of the patellar component. Radiologically the average patellar congruency was similar. In both groups there were 21 non-congruent knees. In group A 8 were symptomatic and had low scores compared to 2 in group B (P<0.05). The mean HSS score and patellar score were higher in group B than in group A (P<0.05).

  2. Dynamic finite element knee simulation for evaluation of knee replacement mechanics.

    PubMed

    Baldwin, Mark A; Clary, Chadd W; Fitzpatrick, Clare K; Deacy, James S; Maletsky, Lorin P; Rullkoetter, Paul J

    2012-02-02

    In vitro pre-clinical testing of total knee replacement (TKR) devices is a necessary step in the evaluation of new implant designs. Whole joint knee simulators, like the Kansas knee simulator (KKS), provide a controlled and repeatable loading environment for comparative evaluation of component designs or surgical alignment under dynamic conditions. Experimental testing, however, is time and cost prohibitive for design-phase evaluation of tens or hundreds of design variations. Experimentally-verified computational models provide an efficient platform for analysis of multiple components, sizes, and alignment conditions. The purpose of the current study was to develop and verify a computational model of a dynamic, whole joint knee simulator. Experimental internal-external and valgus-varus laxity tests, followed by dynamic deep knee bend and gait simulations in the KKS were performed on three cadaveric specimens. Specimen-specific finite element (FE) models of posterior-stabilized TKR were created from magnetic resonance images and CAD geometry. The laxity data was used to optimize mechanical properties of tibiofemoral soft-tissue structures on a specimen-specific basis. Each specimen was subsequently analyzed in a computational model of the experimental KKS, simulating both dynamic activities. The computational model represented all joints and actuators in the experimental setup, including a proportional-integral-derivative (PID) controller to drive quadriceps actuation. The computational model was verified against six degree-of-freedom patellofemoral (PF) and tibiofemoral (TF) kinematics and actuator loading during both deep knee bend and gait activities, with good agreement in trends and magnitudes between model predictions and experimental kinematics; differences were less than 1.8 mm and 2.2° for PF and TF translations and rotations. The whole joint FE simulator described in this study can be applied to investigate a wide range of clinical and research questions.

  3. Effects of Nominal Differences in Cage Height and Floor Space on the Wellbeing of Rabbits.

    PubMed

    Stewart, Kay L; Suckow, Mark A

    2016-03-01

    The 8th edition of the Guide for the Care and Use of Laboratory Animals recommends a cage height of 16 in. for rabbits, compared with 14 in. in the previous edition. In contrast, the Animal Welfare Act Regulations prescribes a cage height of 14 in. for rabbits. A review of the literature failed to identify published data that support an advantage to rabbits having 16 in. of cage height compared with 14 or 15 in. The study described here evaluated the effect of a 3-in. difference in cage height on the health, growth, behavior, and overall wellbeing of rabbits. Groups of 10 New Zealand white rabbits were housed in cages that provided either 15 in. of interior cage height (720 in(2) of floor space) or 18 in. of interior height (784 in(2) of floor space). The rabbits were observed during 25 periods (1 h each) over 7 wk, and various behavioral parameters were scored. In addition, rabbits were weighed weekly, and general clinical health was assessed. After 4 wk, the groups were switched to the alternate housing. No significant differences in body weight gain or behavioral parameters were detected between groups housed in cages with different heights and amounts of floor space, nor were significant behavioral differences noted in individual rabbits when moved from one cage type to the other. In addition, all rabbits remained clinically healthy throughout the study. These results demonstrate that these differences in interior cage height neither benefit nor harm rabbits.

  4. Effects of Nominal Differences in Cage Height and Floor Space on the Wellbeing of Rabbits

    PubMed Central

    Stewart, Kay L; Suckow, Mark A

    2016-01-01

    The 8th edition of the Guide for the Care and Use of Laboratory Animals recommends a cage height of 16 in. for rabbits, compared with 14 in. in the previous edition. In contrast, the Animal Welfare Act Regulations prescribes a cage height of 14 in. for rabbits. A review of the literature failed to identify published data that support an advantage to rabbits having 16 in. of cage height compared with 14 or 15 in. The study described here evaluated the effect of a 3-in. difference in cage height on the health, growth, behavior, and overall wellbeing of rabbits. Groups of 10 New Zealand white rabbits were housed in cages that provided either 15 in. of interior cage height (720 in2 of floor space) or 18 in. of interior height (784 in2 of floor space). The rabbits were observed during 25 periods (1 h each) over 7 wk, and various behavioral parameters were scored. In addition, rabbits were weighed weekly, and general clinical health was assessed. After 4 wk, the groups were switched to the alternate housing. No significant differences in body weight gain or behavioral parameters were detected between groups housed in cages with different heights and amounts of floor space, nor were significant behavioral differences noted in individual rabbits when moved from one cage type to the other. In addition, all rabbits remained clinically healthy throughout the study. These results demonstrate that these differences in interior cage height neither benefit nor harm rabbits. PMID:27025808

  5. Effect of ACL graft material on anterior knee force during simulated in vivo ovine motion applied to the porcine knee: An in vitro examination of force during 2000 cycles.

    PubMed

    Boguszewski, Daniel V; Wagner, Christopher T; Butler, David L; Shearn, Jason T

    2015-12-01

    This study determined how anterior cruciate ligament (ACL) reconstruction affected the magnitude and temporal patterns of anterior knee force and internal knee moment during 2000 cycles of simulated gait. Porcine knees were tested using a six degree-of-freedom robot, examining three porcine allograft materials compared with the native ACL. Reconstructions were performed using: (1) bone-patellar tendon-bone allograft (BPTB), (2) reconstructive porcine tissue matrix (RTM), or (3) an RTM-polymer hybrid construct (Hybrid). Forces and moments were measured over the entire gait cycle and contrasted at heel strike, mid stance, toe off, and peak flexion. The Hybrid construct performed the best, as magnitude and temporal changes in both anterior knee force and internal knee moment were not different from the native ACL knee. Conversely, the RTM knees showed greater loss in anterior knee force during 2000 cycles than the native ACL knee at heel strike and toe off, with an average force loss of 46%. BPTB knees performed the least favorably, with significant loss in anterior knee force at all key points and an average force loss of 61%. This is clinically relevant, as increases in post-operative knee laxity are believed to play a role in graft failure and early onset osteoarthritis.

  6. Technetium-99m-labeled annexin V imaging for detecting prosthetic joint infection in a rabbit model.

    PubMed

    Tang, Cheng; Wang, Feng; Hou, Yanjie; Lu, Shanshan; Tian, Wei; Xu, Yan; Jin, Chengzhe; Wang, Liming

    2015-05-01

    Accurate and timely diagnosis of prosthetic joint infection is essential to initiate early treatment and achieve a favorable outcome. In this study, we used a rabbit model to assess the feasibility of technetium-99m-labeled annexin V for detecting prosthetic joint infection. Right knee arthroplasty was performed on 24 New Zealand rabbits. After surgery, methicillin-susceptible Staphylococcus aureus was intra-articularly injected to create a model of prosthetic joint infection (the infected group, n = 12). Rabbits in the control group were injected with sterile saline (n = 12). Seven and 21 days after surgery, technetium-99m-labeled annexin V imaging was performed in 6 rabbits of each group. Images were acquired 1 and 4 hours after injection of technetium-99m-labeled annexin V (150 MBq). The operated-to-normal-knee activity ratios were calculated for quantitative analysis. Seven days after surgery, increased technetium-99m-labeled annexin V uptake was observed in all cases. However, at 21 days a notable decrease was found in the control group, but not in the infected group. The operated-to-normal-knee activity ratios of the infected group were 1.84 ± 0.29 in the early phase and 2.19 ± 0.34 in the delay phase, both of which were significantly higher than those of the control group (P = 0.03 and P = 0.02). The receiver operator characteristic curve analysis showed that the operated-to-normal-knee activity ratios of the delay phase at 21 days was the best indicator, with an accuracy of 80%. In conclusion, technetium-99m-labeled annexin V imaging could effectively distinguish an infected prosthetic joint from an uninfected prosthetic joint in a rabbit model.

  7. US of the Knee: Scanning Techniques, Pitfalls, and Pathologic Conditions.

    PubMed

    Alves, Timothy I; Girish, Gandikota; Kalume Brigido, Monica; Jacobson, Jon A

    2016-10-01

    Pain and other disorders of the knee are a common presenting complaint in the ambulatory setting. Although the cornerstones of imaging evaluation of the knee are radiographs and magnetic resonance (MR) imaging, ultrasonography (US) is less expensive than MR imaging, easily available, and of comparable accuracy in the evaluation of certain pathologic conditions of the knee. The benefits of US include portability, low cost, high spatial resolution, dynamic imaging, and ability to guide percutaneous interventions when indicated. US also allows direct patient contact, facilitating immediate clinical correlation and the ability to compare with the contralateral knee. US evaluation of the knee can be targeted to a specific region on the basis of the complaint or be a comprehensive review. For comprehensive evaluation, the knee is divided into anterior, medial, lateral, and posterior compartments for structured evaluation of the tendons, ligaments, joint space, osseous structures, as well as peripheral nerves and vasculature. US is particularly well suited for evaluating injuries of the quadriceps and patellar tendons, injuries of the medial and lateral collateral ligaments, joint effusions, and fluid collections around the knee. There is additional utility in evaluation of the distal hamstrings tendons, the iliotibial tract, the superficial patellar cortex, the common peroneal nerve, the popliteal vessels, and juxta-articular cystic collections including Baker cyst. In-depth appreciation of relevant sonographic anatomy, common pathologic conditions, knowledge of important pitfalls, and mastery of US technique will allow one to effectively use this powerful bedside tool for the evaluation of a wide variety of knee disorders. (©)RSNA, 2016.

  8. RAPID KNEE-EXTENSIONS TO INCREASE QUADRICEPS MUSCLE ACTIVITY IN PATIENTS WITH TOTAL KNEE ARTHROPLASTY: A RANDOMIZED CROSS-OVER STUDY

    PubMed Central

    Wilquin, Lousia; Jakobsen, Thomas Linding; Holsgaard-Larsen, Anders; Bandholm, Thomas

    2017-01-01

    Background Inhibition of the quadriceps muscle and reduced knee-extension strength is common shortly following total knee arthroplasty (weeks to months), due to reduced voluntary activation of the quadriceps muscle. In healthy subjects, strength training with heavy loads is known to increase agonist muscle activity, especially if the exercise is conducted using rapid muscle contractions. Purpose The purpose of this study was to examine if patients with total knee arthroplasty could perform rapid knee-extensions using a 10 RM load four to eight weeks after surgery, and the degree to which rapid knee-extensions were associated with greater voluntary quadriceps muscle activity during an experimental strength training session, compared to that elicited using slow knee-extensions. Study Design A randomized cross-over study. Methods Twenty-four patients (age 66.5) 4-8 weeks post total knee arthroplasty randomly performed one set of five rapid, and one set of five slow knee-extensions with the operated leg, using a load of their 10 repetition maximum, while surface electromyography recordings were obtained from the vastus medialis and lateralis of the quadriceps muscle. Results Data from 23 of the 24 included patients were analyzed. Muscle activity was significantly higher during rapid knee-extensions (120.2% [10th-90th percentile: 98.3-149.1]) compared to slow knee-extensions (106.0% [88.8-140.8]) for the vastus lateralis (p<0.01), but not for the vastus medialis (120.8% [90.4-134.0]) and (121.8% [93.0-133.0]) (p = 0.17), respectively. Slow and rapid knee-extensions were performed at a median angular velocity of 19.7 degrees/sec (13.7-24.4) and 51.4 degrees/sec (28.9-63.1), respectively Conclusion Four to eight weeks after their total knee arthroplasty, the patients in the present study were able to conduct rapid knee-extensions according to the experimental protocol with an approximately doubled angular velocity compared to slow knee-extensions. This was associated with

  9. New Generation Lockable Knee Brace

    NASA Technical Reports Server (NTRS)

    1996-01-01

    A knee brace that uses Space Shuttle propulsion technology has moved a step closer to being available to help knee injury and stroke patients and may possibly benefit patients with birth defects, spinal cord injuries, and post-polio conditions. After years of hard work, inventors at NASA's Marshall Space Flight Center (MSFC) in Huntsville, Alabama, have turned over the final design and prototype to industry partners at Horton's Orthotic Lab in Little Rock, Arkansas for further clinical testing. The device, called the Selectively Lockable Knee Brace, may mean faster, less painful rehabilitation for patients by allowing the knee to move when weight is not on the heel. Devices currently on the market lock the knee in a rigid, straight-leg position, or allow continuous free motion. Pictured here is a knee brace prototype being tested and fitted at Horton's Orthotic Lab. The knee brace is just one example of how space technology is being used to improve the lives of people on Earth. NASA's MSFC inventors Michael Shadoan and Neill Myers are space propulsion engineers who use the same mechanisms and materials to build systems for rockets that they used to design and develop the knee brace.

  10. Automatic locking orthotic knee device

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce C. (Inventor)

    1993-01-01

    An articulated tang in clevis joint for incorporation in newly manufactured conventional strap-on orthotic knee devices or for replacing such joints in conventional strap-on orthotic knee devices is discussed. The instant tang in clevis joint allows the user the freedom to extend and bend the knee normally when no load (weight) is applied to the knee and to automatically lock the knee when the user transfers weight to the knee, thus preventing a damaged knee from bending uncontrollably when weight is applied to the knee. The tang in clevis joint of the present invention includes first and second clevis plates, a tang assembly and a spacer plate secured between the clevis plates. Each clevis plate includes a bevelled serrated upper section. A bevelled shoe is secured to the tank in close proximity to the bevelled serrated upper section of the clevis plates. A coiled spring mounted within an oblong bore of the tang normally urges the shoes secured to the tang out of engagement with the serrated upper section of each clevic plate to allow rotation of the tang relative to the clevis plate. When weight is applied to the joint, the load compresses the coiled spring, the serrations on each clevis plate dig into the bevelled shoes secured to the tang to prevent relative movement between the tang and clevis plates. A shoulder is provided on the tang and the spacer plate to prevent overextension of the joint.

  11. Exercise and the Knee Joint.

    ERIC Educational Resources Information Center

    Clarke, H. Harrison, Ed.

    1976-01-01

    This report by the President's Council on Physical Fitness and Sports examines the effects of various forms of physical exercise on the knee joint which, because of its vulnerability, is especially subject to injury. Discussion centers around the physical characteristics of the joint, commonly used measurements for determining knee stability,…

  12. Soreness-related changes in three-dimensional running biomechanics following eccentric knee extensor exercise.

    PubMed

    Paquette, Max R; Peel, Shelby A; Schilling, Brian K; Melcher, Dan A; Bloomer, Richard J

    2017-06-01

    Runners often experience delayed onset muscle soreness (DOMS), especially of the knee extensors, following prolonged running. Sagittal knee joint biomechanics are altered in the presence of knee extensor DOMS but it is unclear how muscle soreness affects lower limb biomechanics in other planes of motion. The purpose of this study was to assess the effects of knee extensor DOMS on three-dimensional (3D) lower limb biomechanics during running. Thirty-three healthy men (25.8 ± 6.8 years; 84.1 ± 9.2 kg; 1.77 ± 0.07 m) completed an isolated eccentric knee extensor damaging protocol to elicit DOMS. Biomechanics of over-ground running at a set speed of 3.35 m s(-1)±5% were measured before eccentric exercise (baseline) and, 24 h and 48 h following exercise in the presence of knee extensor DOMS. Knee flexion ROM was reduced at 48 h (P = 0.01; d = 0.26), and peak knee extensor moment was reduced at 24 h (P = 0.001; d = 0.49) and 48 h (P < 0.001; d = 0.68) compared to baseline. Frontal and transverse plane biomechanics were unaffected by the presence of DOMS (P > 0.05). Peak positive ankle and knee joint powers and, peak negative knee joint power were all reduced from baseline to 24 h and 48 h (P < 0.05). These findings suggest that knee extensor DOMS greatly influences sagittal knee joint angular kinetics and, reduces sagittal power production at the ankle joint. However, knee extensor DOMS does not affect frontal and transverse plane lower limb joint biomechanics during running.

  13. Spontaneously occurring alimentary osteofluorosis associated with proliferative gastroduodenopathy in rabbits.

    PubMed

    Bock, P; Peters, M; Bagó, Z; Wolf, P; Thiele, A; Baumgärtner, W

    2007-09-01

    Growing rabbits from two rabbitries, fed with commercial concentrates and hay, developed painful thickenings of the extremities. Four rabbits from each farm were clinically examined and necropsied. All animals showed multiple moderate to severe osseous proliferations of extremities and mandibles and a mild to severe proliferative gastroduodenopathy. Histologically, periosteal and endosteal hyperostosis and a mild to severe proliferation of the gastric and duodenal mucosa were noted. Bone analyses revealed 12,700 and 15,000 microg fluoride per gram of bone ash in affected rabbits, compared with 550 microg fluoride in a control animal. A highly elevated fluoride content was found in concentrates. Vitamin A levels were moderately increased only in one concentrate, and copper levels were normal. Results indicate that alimentary fluoride intoxication caused prominent bony proliferations in the examined rabbits. Whether the proliferative gastroduodenopathy is related to the elevated fluoride intake or represents an incidentally occurring secondary disease remains to be determined.

  14. Reevaluation of lipolytic activity of growth hormone in rabbit adipocytes.

    PubMed

    Barenton, B; Batifol, V; Combarnous, Y; Dulor, J P; Durand, P; Vezinhet, A

    1984-07-18

    The lipolytic activities of porcine pituitary fractions and purified growth hormone (GH) from human (h), porcine (p), ovine (o) and rabbit (Rb) origin as well as ovine placental lactogen (oPL), were compared to that of ACTH on rabbit adipocytes. All the GH preparations and oPL were equivalent in inhibiting the binding of labelled oGH to liver plasma membranes from pregnant rabbits. ACTH, and to a lesser extent porcine pituitary fractions and hGH, stimulated free fatty acid production by isolated adipocytes. The sensitivity of the adipocytes to these factors was increased when adenosine deaminase was added to the incubation medium. But, RbGH, pGH, oGH and oPL had no effect. We conclude that GH is not directly involved in the control of lipolysis in rabbit adipocytes and that the effect of hGH is rather due to a contamination of this preparation by other pituitary factors.

  15. Repair of rabbit cartilage defect based on the fusion of rabbit bone marrow stromal cells and Nano-HA/PLLA composite material.

    PubMed

    Zhu, Weimin; Guo, Daiqi; Peng, Liangquan; Chen, Yun Fang; Cui, Jiaming; Xiong, Jianyi; Lu, Wei; Duan, Li; Chen, Kang; Zeng, Yanjun; Wang, Daping

    2017-02-01

    Objective To assess the effect of the fusion of rabbit bone marrow stromal cells (rBMSCs) and Nano-hydroxyapatite/poly (l-lactic acid) (Nano-HA/PLLA) in repairing the rabbit knee joint with full-thickness cartilage defect. Method The rBMSCs were isolated and cultured in vitro, and the third generation of rBMSCs was co-cultured with the Nano-HA/PLLA to construct the tissue-engineered cartilage (TEC). Eighteen New Zealand white rabbits were selected and randomly divided into three groups, namely, TEC group, Nano-HA/PLLA group, and control group. A cartilage defect model with the diameter of 4.5 mm and depth of 5 mm was constructed on the articular surface of medial malleolus of rabbit femur. General observation, histological observation, and Wakitani's histological scoring were conducted in the 12th and 24th week postoperatively. Results The results of TEC group indicated that new cartilage tissue was formed on the defect site and subchondral bone achieved physiological integration basically. Histological and immunohistochemical analyses indicated the generation of massive extracellular matrix. In contrast, limited regeneration and reconstruction of cartilage was achieved in the Nano-HA/PLLA group and control group, with a significant difference from the TEC group (p < 0.05). Moreover, the effect of cartilage repair was positively correlated with time. Conclusion The porous Nano-HA/PLLA combined with BMSCs promoted the repair of weight-bearing bone of adult rabbit's knee joint with cartilage defect.

  16. MRI based knee cartilage assessment

    NASA Astrophysics Data System (ADS)

    Kroon, Dirk-Jan; Kowalski, Przemyslaw; Tekieli, Wojciech; Reeuwijk, Els; Saris, Daniel; Slump, Cornelis H.

    2012-03-01

    Osteoarthritis is one of the leading causes of pain and disability worldwide and a major health problem in developed countries due to the gradually aging population. Though the symptoms are easily recognized and described by a patient, it is difficult to assess the level of damage or loss of articular cartilage quantitatively. We present a novel method for fully automated knee cartilage thickness measurement and subsequent assessment of the knee joint. First, the point correspondence between a pre-segmented training bone model is obtained with use of Shape Context based non-rigid surface registration. Then, a single Active Shape Model (ASM) is used to segment both Femur and Tibia bone. The surfaces obtained are processed to extract the Bone-Cartilage Interface (BCI) points, where the proper segmentation of cartilage begins. For this purpose, the cartilage ASM is trained with cartilage edge positions expressed in 1D coordinates at the normals in the BCI points. The whole cartilage model is then constructed from the segmentations obtained in the previous step. An absolute thickness of the segmented cartilage is measured and compared to the mean of all training datasets, giving as a result the relative thickness value. The resulting cartilage structure is visualized and related to the segmented bone. In this way the condition of the cartilage is assessed over the surface. The quality of bone and cartilage segmentation is validated and the Dice's coefficients 0.92 and 0.86 for Femur and Tibia bones and 0.45 and 0.34 for respective cartilages are obtained. The clinical diagnostic relevance of the obtained thickness mapping is being evaluated retrospectively. We hope to validate it prospectively for prediction of clinical outcome the methods require improvements in accuracy and robustness.

  17. [Arthroscopic treatment for osteoarthritic knee].

    PubMed

    Bloom, Shlomo; Lebel, David; Cohen, Eugen; Atar, Dan; Rath, Ehud

    2008-04-01

    Osteoarthritis (OA) is the leading cause of knee morbidity. Age and overweight are the main risk factors for development of knee OA. The majority of patients respond to conservative treatment. For those who don't, surgical treatment is the only alternative. Arthroscopic surgery for the osteoarthritic knee is a well known procedure. Recently, numerous publications addressed the advantages of arthroscopic treatment for this indication. Some of the publications concluded that arthroscopic treatment for knee OA equals placebo. Others found temporary relief of symptoms. Among special subgroup of patients, in which acute pain exacerbation, mechanical block or early OA, utilizing arthroscopic techniques revealed satisfactory results. In this review, we discuss the indications and contraindications for arthroscopic treatment of the osteoarthritic knee according to the latest literature.

  18. Anterior knee pain.

    PubMed

    LLopis, Eva; Padrón, Mario

    2007-04-01

    Anterior knee pain is a common complain in all ages athletes. It may be caused by a large variety of injuries. There is a continuum of diagnoses and most of the disorders are closely related. Repeated minor trauma and overuse play an important role for the development of lesions in Hoffa's pad, extensor mechanism, lateral and medial restrain structures or cartilage surface, however usually an increase or change of activity is referred. Although the direct relation of cartilage lesions, especially chondral, and pain is a subject of debate these lesions may be responsible of early osteoarthrosis and can determine athlete's prognosis. The anatomy and biomechanics of patellofemoral joint is complex and symptoms are often unspecific. Transient patellar dislocation has MR distinct features that provide evidence of prior dislocation and rules our complication. However, anterior knee pain more often is related to overuse and repeated minor trauma. Patella and quadriceps tendon have been also implicated in anterior knee pain, as well as lateral or medial restraint structures and Hoffa's pad. US and MR are excellent tools for the diagnosis of superficial tendons, the advantage of MR is that permits to rule out other sources of intraarticular derangements. Due to the complex anatomy and biomechanic of patellofemoral joint maltracking is not fully understood; plain films and CT allow the study of malalignment, new CT and MR kinematic studies have promising results but further studies are needed. Our purpose here is to describe how imaging techniques can be helpful in precisely defining the origin of the patient's complaint and thus improve understanding and management of these injuries.

  19. [Pathogenesis of knee osteoarthrist].

    PubMed

    Bennemann, M; Hönle, W; Simank, H G; Schuh, A

    2007-06-21

    More than 20% of the population of over 60-year olds suffers from degenerative joint diseases of the lower extremities. The cause of primary osteoarthritis of the knee is still unknown. A multifactorial genesis is presumed that includes genetic, nutritional, hormonal and age-related factors. On the other hand, secondary osteoarthritis is a sequela of predisposing factors. The most frequent are axial deformities, pre-existing conditions or injuries. Pre-osteoarthritis appears as dysplasias and dystopias (abnormal presentation) of the patella and axial misalignments, incongruities and joint damage after fractures. The result is the mechanical destruction of the cartilage that, in turn, initiates a vicious circle of further cartilage loss.

  20. Prosthetic knee design by simulation

    SciTech Connect

    Hollerbach, K; Hollister, A

    1999-07-30

    Although 150,000 total knee replacement surgeries are performed annually in North America, current designs of knee prostheses have mechanical problems that include a limited range of motion, abnormal gait patterns, patellofemoral joint dysfunction, implant loosening or subsidence, and excessive wear. These problems fall into three categories: failure to reproduce normal joint kinematics, which results in altered limb function; bone-implant interface failure; and material failure. Modern computer technology can be used to design, prototype, and test new total knee implants. The design team uses the full range of CAD-CAM to design and produce implant prototypes for mechanical and clinical testing. Closer approximation of natural knee kinematics and kinetics is essential for improved patient function and diminished implant loads. Current knee replacement designs are based on 19th Century theories that the knee moves about a variable axis of rotation. Recent research has shown, however, that knee motion occurs about two fixed, offset axes of rotation. These aces are not perpendicular to the long axes of the bones or to each other, and the axes do not intersect. Bearing surfaces of mechanisms that move about axes of rotation are surfaces of revolution of those axes which advanced CAD technology can produce. Solids with surfaces of revolution for the two axes of rotation for the knee have been made using an HP9000 workstation and Structural Ideas Master Series CAD software at ArthroMotion. The implant's CAD model should closely replicate movements of the normal knee. The knee model will have a range of flexion-extension (FE) from -5 to 120 degrees. Movements include varus, valgus, internal and external rotation, as well as flexion and extension. The patellofemoral joint is aligned perpendicular to the FE axis and replicates the natural joint more closely than those of existing prostheses. The bearing surfaces will be more congruent than current designs and should

  1. 49 CFR 572.166 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Knees and knee impact test procedure. 572.166... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.166 Knees and knee impact test procedure. The knee assembly is assembled and tested as specified in 49 CFR 572.126 (Subpart N)....

  2. 49 CFR 572.166 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Knees and knee impact test procedure. 572.166... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.166 Knees and knee impact test procedure. The knee assembly is assembled and tested as specified in 49 CFR 572.126 (Subpart N)....

  3. 21 CFR 888.3570 - Knee joint femoral (hemi-knee) metallic uncemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Knee joint femoral (hemi-knee) metallic uncemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3570 Knee joint femoral (hemi-knee) metallic uncemented prosthesis. (a) Identification. A knee joint femoral...

  4. 21 CFR 888.3570 - Knee joint femoral (hemi-knee) metallic uncemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint femoral (hemi-knee) metallic uncemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3570 Knee joint femoral (hemi-knee) metallic uncemented prosthesis. (a) Identification. A knee joint femoral...

  5. 21 CFR 888.3570 - Knee joint femoral (hemi-knee) metallic uncemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Knee joint femoral (hemi-knee) metallic uncemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3570 Knee joint femoral (hemi-knee) metallic uncemented prosthesis. (a) Identification. A knee joint femoral...

  6. 21 CFR 888.3570 - Knee joint femoral (hemi-knee) metallic uncemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Knee joint femoral (hemi-knee) metallic uncemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3570 Knee joint femoral (hemi-knee) metallic uncemented prosthesis. (a) Identification. A knee joint femoral...

  7. 49 CFR 572.166 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 7 2012-10-01 2012-10-01 false Knees and knee impact test procedure. 572.166... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.166 Knees and knee impact test procedure. The knee assembly is assembled and tested as specified in 49 CFR 572.126 (Subpart N)....

  8. 49 CFR 572.166 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false Knees and knee impact test procedure. 572.166... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.166 Knees and knee impact test procedure. The knee assembly is assembled and tested as specified in 49 CFR 572.126 (Subpart N)....

  9. 21 CFR 888.3570 - Knee joint femoral (hemi-knee) metallic uncemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Knee joint femoral (hemi-knee) metallic uncemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3570 Knee joint femoral (hemi-knee) metallic uncemented prosthesis. (a) Identification. A knee joint femoral...

  10. 49 CFR 572.166 - Knees and knee impact test procedure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Knees and knee impact test procedure. 572.166... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.166 Knees and knee impact test procedure. The knee assembly is assembled and tested as specified in 49 CFR 572.126 (Subpart N)....

  11. The influence of a user-adaptive prosthetic knee across varying walking speeds: A randomized cross-over trial.

    PubMed

    Prinsen, E C; Nederhand, M J; Sveinsdóttir, H S; Prins, M R; van der Meer, F; Koopman, H F J M; Rietman, J S

    2017-01-01

    Previously conducted trials comparing the gait pattern of individuals with a transfemoral amputation using a user-adaptive and a non-microprocessor-controlled prosthetic knee (NMPK) found mixed and conflicting results. Few trials, however, have compared user-adaptive to non-adaptive prosthetic knees across different walking speeds. Because of the ability of variable damping, the effect of user-adaptive knees might be more pronounced at lower or higher walking speeds. Our aim was to compare the Rheo Knee II (a microprocessor-controlled prosthetic knee) with NMPKs across varying walking speeds. In addition, we studied compensatory mechanisms associated with non-optimal prosthetic knee kinematics, such as intact ankle vaulting and vertical acceleration of the pelvis. Nine persons with a transfemoral amputation or knee disarticulation were included and measured with their own NMPK and with the Rheo Knee II. Measurements were performed at three walking speeds: preferred walking speed, 70% preferred walking speed and 115% preferred walking speed. No differences on peak prosthetic knee flexion during swing were found between prosthetic knee conditions. In addition, prosthetic knee flexion increased significantly with walking speed for both prosthetic knee conditions. At 70% preferred walking speed we found that vaulting of the intact ankle was significantly decreased while walking with the Rheo Knee II compared to the NMPK condition (P=0.028). We did not find differences in peak vertical acceleration of the pelvis during initial and mid-swing of the prosthetic leg. In conclusion, comparison of walking with the Rheo Knee II to walking with a NMPK across different walking speeds showed limited differences in gait parameters.

  12. Effect of housing conditions on production, carcass and meat quality traits of growing rabbits.

    PubMed

    Matics, Zs; Szendrő, Zs; Odermatt, M; Gerencsér, Zs; Nagy, I; Radnai, I; Dalle Zotte, A

    2014-01-01

    Production, carcass traits and meat quality of rabbits housed in cages or in different pens were compared. Rabbits (n=579) were sorted into 5 groups: C=cage (2 rabbits/cage); pen without platform: P11=9 rabbits/pen; P16=14 rabbits/pen; pen with platform: PW=wire net platform, 14 rabbits/pen; PD=platform with straw-litter, 14 rabbits/pen. Feed intake and average daily gain between 5 and 11 weeks, and body weight at 11 weeks were significantly higher in C rabbits than that of the mean of pen-housed groups, while the PD group had the lowest growth performance. C rabbits had the smallest hind part to reference carcass (P<0.001) and the largest percentage of perirenal and scapular fat (P<0.001). The meat/bone ratio was the largest in group C (P<0.05). Differences were recorded in a* value and lipid content of m. Longissimus dorsi. Rabbits housed in cages generally had the best performance whereas those housed in pens with platform exhibited the worst.

  13. Muscle strength and knee range of motion after femoral lengthening

    PubMed Central

    Bhave, Anil; Shabtai, Lior; Woelber, Erik; Apelyan, Arman; Paley, Dror; Herzenberg, John E

    2017-01-01

    Background and purpose Femoral lengthening may result in decrease in knee range of motion (ROM) and quadriceps and hamstring muscle weakness. We evaluated preoperative and postoperative knee ROM, hamstring muscle strength, and quadriceps muscle strength in a diverse group of patients undergoing femoral lengthening. We hypothesized that lengthening would not result in a significant change in knee ROM or muscle strength. Patients and methods This prospective study of 48 patients (mean age 27 (9–60) years) compared ROM and muscle strength before and after femoral lengthening. Patient age, amount of lengthening, percent lengthening, level of osteotomy, fixation time, and method of lengthening were also evaluated regarding knee ROM and strength. The average length of follow-up was 2.9 (2.0–4.7) years. Results Mean amount of lengthening was 5.2 (2.4–11.0) cm. The difference between preoperative and final knee flexion ROM was 2° for the overall group. Congenital shortening cases lost an average of 5% or 6° of terminal knee flexion, developmental cases lost an average of 3% or 4°, and posttraumatic cases regained all motion. The difference in quadriceps strength at 45° preoperatively and after lengthening was not statistically or clinically significant (2.7 Nm; p = 0.06). Age, amount of lengthening, percent lengthening, osteotomy level, fixation time, and lengthening method had no statistically significant influence on knee ROM or quadriceps strength at final follow-up. Interpretation Most variables had no effect on ROM or strength, and higher age did not appear to be a limiting factor for femoral lengthening. Patients with congenital causes were most affected in terms of knee flexion. PMID:27892743

  14. Synovial inflammation in patients with different stages of knee osteoarthritis.

    PubMed

    Ene, Răzvan; Sinescu, Ruxandra Diana; Ene, Patricia; Cîrstoiu, Monica Mihaela; Cîrstoiu, Florin Cătălin

    2015-01-01

    The synovium is an intra-articular mesenchymal tissue and essential for the normal joint function. It is involved in many pathological characteristic processes and sometimes specific for this distinctive tissue. In this study, we refer to synovial proliferative disorders according to the stage of osteoarthritis (OA) disease. Forty-three patients with knee OA were treated in the Department of Orthopedics and Traumatology, Emergency University Hospital of Bucharest, Romania, in the last two years. In all cases, we used at least five criteria for the knee OA: knee pain, knee joint tenderness, no palpable warmth over the knee, stiffness, erythrocyte sedimentation rate and C-reactive protein levels. In all the cases the synovial tissue was selected by the orthopedic surgeon. X-ray examination was taken in every case of the affected joint. Patients who were considered to have early OA underwent arthroscopic synovial biopsy of the symptomatic joint. Synovial tissue samples from patients with late OA were obtained at the time of knee joint arthroplasty. Microscopic examination in early osteoarthritis revealed for more than half of patients with synovial biopsy through arthroscopic technique having synovitis lesions with mononuclear infiltrates, diffuse fibrosis, thickening of the lining layer, macrophages appearance and neoformation vessels also. The synovitis seen in advanced OA knees tends to be diffuse and is not mandatory localized to areas of chondral defects, although an association has been reported between chondral defects and associated synovitis in the knee medial tibio-femoral compartment. The overexpression of mediators of inflammation and the increased mononuclear cell infiltration were seen in early OA, compared with late OA.

  15. Mobile bearings in primary knee arthroplasty.

    PubMed

    Vertullo, C J; Easley, M E; Scott, W N; Insall, J N

    2001-01-01

    Mobile-bearing knee arthroplasty (MBKA) has potential advantages compared with conventional fixed-bearing total knee arthroplasty (TKA). By allowing unconstrained axial rotation, MBKA can offer greater articular conformity without an increased probability of loosening due to increased axial torque. Increased articular conformity minimizes polyethylene contact stresses, thereby reducing linear wear and subsurface fatigue failure. Axial rotation of the platform also enables self-correction of tibial component malrotation. Despite these advantages, the long-term clinical results obtained with current MBKA devices are similar to those obtained with well-designed fixed-bearing TKA prostheses, with no data suggesting their superiority. The disadvantages of MBKA include bearing dislocation and breakage, soft-tissue impingement, a steep technique learning curve, and concerns about volumetric wear. Hypothetically, longer-term follow-up of MBKA results may reveal a significant difference from fixed-bearing TKA results as the fatigue failure threshold of incongruent polyethylene is exceeded.

  16. Improved radiographic outcomes with patient-specific total knee arthroplasty.

    PubMed

    Ivie, Conrad B; Probst, Patrick J; Bal, Amrit K; Stannard, James T; Crist, Brett D; Sonny Bal, B

    2014-11-01

    Patient-specific guides can improve limb alignment and implant positioning in total knee arthroplasty, although not all studies have supported this benefit. We compared the radiographs of 100 consecutively-performed patient-specific total knees to a similar group that was implanted with conventional instruments instead. The patient-specific group showed more accurate reproduction of the theoretically ideal mechanical axis, with fewer outliers, but implant positioning was comparable between groups. Our odds ratio comparison showed that the patient-specific group was 1.8 times more likely to be within the desired +3° from the neutral mechanical axis when compared to the standard control group. Our data suggest that reliable reproduction of the limb mechanical axis may accrue from patient-specific guides in total knee arthroplasty when compared to standard, intramedullary instrumentation.

  17. Does Cruciate-Retaining Total Knee Arthroplasty Show Better Quadriceps Recovery than Posterior-Stabilized Total Knee Arthroplasty? - Objective Measurement with a Dynamometer in 102 Knees

    PubMed Central

    Cho, Kye-Youl; Song, Sang-Jun; Bae, Dae-Kyung

    2016-01-01

    Background Cruciate-retaining (CR) prostheses have been considered to produce more physiologic femoral rollback, provide better proprioception, and result in better quadriceps recovery than posterior-stabilized (PS) prostheses after total knee arthroplasty (TKA). However, there are very few studies demonstrating these benefits in an objective manner. We investigated whether CR-TKA could result in (1) better quadriceps recovery; (2) a greater proportion of patients with beyond the preoperative level of recovery; and (3) better clinical outcomes than PS-TKA. Methods This was a prospective non-randomized comparative study on the results of CR-TKA and PS-TKA. CR prostheses were used in 51 knees and PS prostheses in 51 knees. Quadriceps force was measured with a dynamometer preoperatively and at postoperative 6 weeks, 3 months, and 6 months consecutively. The Knee Society score (KSS) and range of motion (ROM) were also evaluated. Results There were no differences between two groups in terms of the objective quadriceps force during the follow-up period. The proportion of patients with beyond the preoperative level of recovery was similar between groups. Moreover, the KSS and ROM were not significantly different between two groups. Conclusions CR-TKA did not result in better quadriceps recovery than PS-TKA during the 6-month follow-up. In other words, PS-TKA could lead to comparable quadriceps recovery despite greater preoperative weaknesses such as more restricted ROM and more severe degenerative changes of the knee. PMID:27904719

  18. Exercise for knee osteoarthritis.

    PubMed

    Baker, K; McAlindon, T

    2000-09-01

    Adverse outcomes in knee osteoarthritis include pain, loss of function, and disability. These outcomes can have devastating effects on the quality of life of those suffering from the disease. Treatments have generally targeted pain, assuming that disability would improve as a direct result of improvements in pain. However, there is evidence to suggest that determinants of pain and disability differ. In general, treatments have been more successful at decreasing pain rather than disability. Many of the factors that lead to disability can be improved with exercise. Exercise, both aerobic and strength training, have been examined as treatments for knee osteoarthritis, with considerable variability in the results. The variability between studies may be due to differences in study design, exercise protocols, and participants in the studies. Although there is variability among studies, it is notable that a majority of the studies had a positive effect on pain and or disability. The mechanism of exercise remains unclear and merits future studies to better define a concise, clear exercise protocol that may have the potential for a public health intervention.

  19. Critical seeding density improves the properties and translatability of self-assembling anatomically shaped knee menisci.

    PubMed

    Hadidi, Pasha; Yeh, Timothy C; Hu, Jerry C; Athanasiou, Kyriacos A

    2015-01-01

    A recent development in the field of tissue engineering is the rise of all-biologic, scaffold-free engineered tissues. Since these biomaterials rely primarily upon cells, investigation of initial seeding densities constitutes a particularly relevant aim for tissue engineers. In this study, a scaffold-free method was used to create fibrocartilage in the shape of the rabbit knee meniscus. The objectives of this study were to: (i) determine the minimum seeding density, normalized by an area of 44 mm(2), necessary for the self-assembling process of fibrocartilage to occur; (ii) examine relevant biomechanical properties of engineered fibrocartilage, such as tensile and compressive stiffness and strength, and their relationship to seeding density; and (iii) identify a reduced, or optimal, number of cells needed to produce this biomaterial. It was found that a decreased initial seeding density, normalized by the area of the construct, produced superior mechanical and biochemical properties. Collagen per wet weight, glycosaminoglycans per wet weight, tensile properties and compressive properties were all significantly greater in the 5 million cells per construct group as compared to the historical 20 million cells per construct group. Scanning electron microscopy demonstrated that a lower seeding density results in a denser tissue. Additionally, the translational potential of the self-assembling process for tissue engineering was improved though this investigation, as fewer cells may be used in the future. The results of this study underscore the potential for critical seeding densities to be investigated when researching scaffold-free engineered tissues.

  20. Tribology studies of the natural knee using an animal model in a new whole joint natural knee simulator.

    PubMed

    Liu, Aiqin; Jennings, Louise M; Ingham, Eileen; Fisher, John

    2015-09-18

    The successful development of early-stage cartilage and meniscus repair interventions in the knee requires biomechanical and biotribological understanding of the design of the therapeutic interventions and their tribological function in the natural joint. The aim of this study was to develop and validate a porcine knee model using a whole joint knee simulator for investigation of the tribological function and biomechanical properties of the natural knee, which could then be used to pre-clinically assess the tribological performance of cartilage and meniscal repair interventions prior to in vivo studies. The tribological performance of standard artificial bearings in terms of anterior-posterior (A/P) shear force was determined in a newly developed six degrees of freedom tribological joint simulator. The porcine knee model was then developed and the tribological properties in terms of shear force measurements were determined for the first time for three levels of biomechanical constraints including A/P constrained, spring force semi-constrained and A/P unconstrained conditions. The shear force measurements showed higher values under the A/P constrained condition (predominantly sliding motion) compared to the A/P unconstrained condition (predominantly rolling motion). This indicated that the shear force simulation model was able to differentiate between tribological behaviours when the femoral and tibial bearing was constrained to slide or/and roll. Therefore, this porcine knee model showed the potential capability to investigate the effect of knee structural, biomechanical and kinematic changes, as well as different cartilage substitution therapies on the tribological function of natural knee joints.

  1. Therapeutic Experience on Stance Control Knee-Ankle-Foot Orthosis With Electromagnetically Controlled Knee Joint System in Poliomyelitis

    PubMed Central

    Kim, Jung-Hwan; Ji, Sang-Goo; Jung, Kang-Jae

    2016-01-01

    A 54-year-old man with poliomyelitis had been using a conventional, passive knee-ankle-foot orthosis (KAFO) with a drop ring lock knee joint for about 40 years. A stance control KAFO (SCKAFO) with an electromagnetically controlled (E-MAG) knee joint system was prescribed. To correct his gait pattern, he also underwent rehabilitation therapy, which included muscle re-education, neuromuscular electrical stimulation, strengthening exercises for the lower extremities, and balance training twice a week for about 4 months. Both before and after rehabilitation, we conducted a gait analysis and assessed the physiological cost index in energy expended during walking in a locked-knee state and while he wore a SCKAFO with E-MAG. When compared with the pre-rehabilitation data, the velocity, step length, stride length, and knee kinematic data were improved after rehabilitation. Although the SCKAFO with E-MAG system facilitated the control of knee motion during ambulation, appropriate rehabilitative therapy was also needed to achieve a normal gait pattern. PMID:27152288

  2. New Generation Lockable Knee Brace

    NASA Technical Reports Server (NTRS)

    2000-01-01

    A knee brace that uses Space Shuttle propulsion technology has moved a step closer to being available to help knee injury and stroke patients and may possibly benefit patients with birth defects, spinal cord injuries, and post-polio conditions. After years of hard work, inventors at NASA's Marshall Space Flight Center (MSFC) in Huntsville, Alabama, have turned over the final design and prototype to industry partners at Horton's Orthotic Lab in Little Rock, Arkansas for further clinical testing. The device, called the Selectively Lockable Knee Brace, may mean faster, less painful rehabilitation for patients by allowing the knee to move when weight is not on the heel. Devices currently on the market lock the knee in a rigid, straight-leg position, or allow continuous free motion. The knee brace is just one example of how space technology is being used to improve the lives of people on Earth. NASA's MSFC inventors Michael Shadoan and Neill Myers are space propulsion engineers who use the same mechanisms and materials to build systems for rockets that they used to design and develop the knee brace.

  3. Physiotherapy management of knee osteoarthritis.

    PubMed

    Page, Carolyn J; Hinman, Rana S; Bennell, Kim L

    2011-05-01

    Knee osteoarthritis (OA) is a prevalent chronic joint disease causing pain and disability. Physiotherapy, which encompasses a number of modalities, is a non-invasive treatment option in the management of OA. This review summarizes the evidence for commonly used physiotherapy interventions. There is strong evidence to show short-term beneficial effects of exercise on pain and function, although the type of exercise does not seem to influence treatment outcome. Delivery modes, including individual, group or home exercise are all effective, although therapist contact may improve benefits. Attention to improving adherence to exercise is needed to maximize outcomes in the longer-term. Knee taping applied with the aim of realigning the patella and unloading soft tissues can reduce pain. There is also evidence to support the use of knee braces in people with knee OA. Biomechanical studies show that lateral wedge shoe insoles reduce knee load but clinical trials do not support symptomatic benefits. Recent studies suggest individual shoe characteristics also affect knee load and there is current interest in the effect of modified shoe designs. Manual therapy, while not to be used as a stand-alone treatment, may be beneficial. In summary, although the research is not equivocal, there is sufficient evidence to indicate that physiotherapy interventions can reduce pain and improve function in those with knee OA.

  4. Pharmacokinetics and ocular penetration of grepafloxacin in albino and pigmented rabbits.

    PubMed

    Perez, S; Solans, C; Bregante, M A; Pinilla, I; García, M A; Honrubia, F

    2002-10-01

    The pharmacokinetics of grepafloxacin were determined in albino and pigmented rabbits following a single 10 mg/kg intravenous administration. The penetration of grepafloxacin into various ocular tissues was also determined after continuous intravenous infusion in both types of animal. Grepafloxacin showed a bicompartmental model of distribution in both pigmented and albino rabbits with significant differences in the pharmacokinetics between the two types of animal. After continuous intravenous infusion, significantly greater penetration of grepafloxacin was found in the iris, cornea and chorioretina of pigmented rabbits compared with albino rabbits.

  5. Assessing Anticalcification Treatments in Bioprosthetic Tissue by Using the New Zealand Rabbit Intramuscular Model

    PubMed Central

    Wright, Gregory A; Faught, Joelle M; Olin, Jane M

    2009-01-01

    The objective of this work was to demonstrate that the New Zealand White (NZW) rabbit intramuscular model can be used for detecting calcification in bioprosthetic tissue and to compare the calcification in the rabbit to that of native human valves. The rabbit model was compared with the commonly used Sprague–Dawley rat subcutaneous model. Eighteen rabbits and 18 rats were used to assess calcification in bioprosthetic tissue over time (7, 14, 30, and 90 d). The explanted rabbit and rat tissue discs were measured for calcium by using atomic absorption and Raman spectroscopy. Calcium deposits on the human valve explants were assessed by using Raman spectroscopy. The results showed that the NZW rabbit model is robust for detecting calcification in a shorter duration (14 d), with less infection complications, more space to implant tissue groups (thereby reducing animal use numbers), and a more metabolically and mechanically dynamic environment than the rat subcutaneous model . The human explanted valves and rabbit explanted tissue both showed Raman peaks at 960 cm−1 which is representative of hydroxyapatite. Hydroxyapatite is the final calcium and phosphate species in the calcification of bioprosthetic heart valves and rabbit intramuscular implants. The NZW rabbit intramuscular model is an effective model for assessing calcification in bioprosthetic tissue. PMID:19619417

  6. Cardiac Tissue Doppler and Tissue Velocity Imaging in Anesthetized New Zealand White Rabbits

    PubMed Central

    Pelosi, Augusta; John, Linda St; Gaymer, Jean; Ferguson, Danielle; Goyal, Sandeep K; Abela, George S; Rubinstein, Jack

    2011-01-01

    New Zealand white rabbits are commonly used in cardiovascular research. Complete echocardiographic examination of the heart includes the evaluation of tissue Doppler (TDI) parameters, yet normal data are unavailable for rabbits. In addition, tissue velocity imaging (TV) is a potentially useful measure of myocardial function that has not yet been applied to rabbits. Anesthetized New Zealand white rabbits (n = 31) underwent echocardiography to establish the feasibility of performing TDI and TV and establishing corresponding reference values. Standard 2D, M-mode, and Doppler measurements were obtained in all rabbits and showed values comparable to previously published data. Interpretable TDI images were obtained in all 31 rabbits and TV in 24 of 31 rabbits. The values obtained were similar to those seen in healthy cats and are comparable to the values found in adult humans. TDI and TV can easily be added to standard echocardiographic evaluation in rabbits. The values from the current study, obtained in normal rabbits, can be used as reference values to improve characterization of cardiac disease in this species. PMID:21640025

  7. The influence of knee position on ankle dorsiflexion - a biometric study

    PubMed Central

    2014-01-01

    Background Musculus gastrocnemius tightness (MGT) can be diagnosed by comparing ankle dorsiflexion (ADF) with the knee extended and flexed. Although various measurement techniques exist, the degree of knee flexion needed to eliminate the effect of the gastrocnemius on ADF is still unknown. The aim of this study was to identify the minimal degree of knee flexion required to eliminate the restricting effect of the musculus gastrocnemius on ADF. Methods Bilateral ADF of 20 asymptomatic volunteers aged 18-40 years (50% female) was assessed prospectively at six different degrees of knee flexion (0°, 20°, 30°, 45°, 60°, 75°, Lunge). Tests were performed following a standardized protocol, non weightbearing and weightbearing, by two observers. Statistics comprised of descriptive statistics, t-tests, repeated measurement ANOVA and ICC. Results 20 individuals with a mean age of 27 ± 4 years were tested. No significant side to side differences were observed. The average ADF [95% confidence interval] for non weightbearing was 4° [1°-8°] with the knee extended and 20° [16°-24°] for the knee 75° flexed. Mean weightbearing ADF was 25° [22°-28°] for the knee extended and 39° [36°-42°] for the knee 75° flexed. The mean differences between 20° knee flexion and full extension were 15° [12°-18°] non weightbearing and 13° [11°-16°] weightbearing. Significant differences of ADF were only found between full extension and 20° of knee flexion. Further knee flexion did not increase ADF. Conclusion Knee flexion of 20° fully eliminates the ADF restraining effect of the gastrocnemius. This knowledge is essential to design a standardized clinical examination assessing MGT. PMID:25053374

  8. Lower extremity joint position sense in runners with and without a history of knee overuse injury.

    PubMed

    Foch, Eric; Milner, Clare E

    2012-07-01

    Kinematic and kinetic analyses are routinely implemented to determine if gait differences exist between runners with and without a history of knee injury. Hip and knee kinematic differences have been reported between knee injured and non-injured runners. Yet, there is no consensus on whether these differences are the primary variables contributing to knee injury. Furthermore, there may be additional underlying factors that contribute to the development of injury that cannot be determined by gait analysis. The purpose of this investigation was to determine if joint position sense differences exist in runners with and without a history of knee overuse injury. Sagittal plane knee and hip joint position sense was measured in 13 runners with a history of knee overuse injury and 13 runners with no history of knee overuse injury. Absolute joint position replication error was measured during both a weight bearing and a non-weight bearing condition. Joint position replication errors at each joint were compared among groups and task using a two-way ANOVA with joint task as the repeated measure. Knee and hip joint replication errors were similar between both groups. The weight bearing and non-weight bearing tasks resulted in similar joint position replication errors. There were no interaction effects. In conclusion, knee flexion and hip adduction joint position sense is similar in runners with and without a history of knee overuse injury. Therefore, joint position sense measured via weight bearing and non-weight bearing joint position replication tasks may not play an important role in the development of knee overuse injury.

  9. Accuracy of clinical diagnosis in knee arthroscopy.

    PubMed Central

    Brooks, Stuart; Morgan, Mamdouh

    2002-01-01

    A prospective study of 238 patients was performed in a district general hospital to assess current diagnostic accuracy rates and to ascertain the use and the effectiveness of magnetic resonance imaging (MRI) scanning in reducing the number of negative arthroscopies. The pre-operative diagnosis of patients listed for knee arthroscopy was medial meniscus tear 94 (40%) and osteoarthritis 59 (25%). MRI scans were requested in 57 patients (24%) with medial meniscus tear representing 65% (37 patients). The correlation study was done between pre-operative diagnosis, MRI and arthroscopic diagnosis. Clinical diagnosis was as accurate as the MRI with 79% agreement between the preoperative diagnosis and arthroscopy compared to 77% agreement between MRI scan and arthroscopy. There was no evidence, in this study, that MRI scan can reduce the number of negative arthroscopies. Four normal MRI scans had positive arthroscopic diagnosis (two torn medial meniscus, one torn lateral meniscus and one chondromalacia patella). Out of 240 arthroscopies, there were only 10 normal knees (negative arthroscopy) representing 4% of the total number of knee arthroscopies; one patient of those 10 cases had MRI scan with ACL rupture diagnosis. Images Figure 1 Figure 2 PMID:12215031

  10. Confirmation and phylogenetic analysis of rabbit hemorrhagic disease virus in free-living rabbits from the Netherlands.

    PubMed

    van de Bildt, M W G; van Bolhuis, G H; van Zijderveld, F; van Riel, D; Drees, J M; Osterhaus, A D M E; Kuiken, T

    2006-10-01

    The number of free-living European rabbits (Oryctolagus cuniculus) in the Netherlands has declined dramatically in recent years. Although rabbit hemorrhagic disease virus (RHDV) infection has been implicated as a possible cause of this decline, the definitive diagnosis has not been reported. We examined three free-living rabbits found dead in the Netherlands in 2004 by use of gross pathology, histopathology, immunohistochemistry, and reverse transcriptase polymerase chain reaction. We subsequently compared the identified virus with RHDV from elsewhere in the world by phylogenetic analysis. There was widespread necrosis, hemorrhage, or both in liver, kidney, spleen, and lungs of all three rabbits, consistent with RHDV infection. The presence of RHDV in affected tissues was demonstrated by immunohistochemistry and reverse transcriptase polymerase chain reaction. The RHDV from the Netherlands showed the highest identity, 99%, with a strain from France in 2000, and fitted in genogroup G5. These results prove that RHDV infection causes mortality of free-living rabbits in the Netherlands and suggest that RHDV strains circulating in free-living rabbits in the Netherlands and France have a common source or that one has originated from the other.

  11. Is there a difference between hare syphilis and rabbit syphilis? Cross infection experiments between rabbits and hares.

    PubMed

    Lumeij, Johannes T; Mikalová, Lenka; Smajs, David

    2013-05-31

    Cross infection of rabbits and hares with Treponema paraluiscuniculi from rabbits and the related microorganism from hares, which was provisionally named "Treponema paraluisleporis", revealed that T. paraluiscuniculi affects rabbits clinically, but only causes seroconversion in hares without causing clinical disease, while "T. paraluisleporis" induces disease in both rabbits and hares. The 16S rRNA gene of "T. paraluisleporis" was sequenced (GenBank acc. no. JX899416) and compared to the sequence of T. paraluiscuniculi strain Cuniculi A. A phylogenetic tree based on the sequence alignment of 2002 bp taken from several treponemal strains was constructed. Both "T. paraluisleporis" and T. paraluiscuniculi are clustered together indicating their common origin. The close phylogenetic relatedness of both representatives supports the conclusion that subspecies or ecovar status should be given to these strains rather than species status. A more appropriate species name might be Treponema paraluisleporidarum. The genitive refers to the nominative Leporidae (family of rabbits and hares). The naturally occurring strain in rabbits would than be T. paraluisleporidarum ecovar Cuniculus and the strain from hares T. paraluisleporidarum ecovar Lepus. Since the former seems to have fewer physiological hosts, ecovar Lepus may represent an evolutionary ancestor of ecovar Cuniculus.

  12. Preliminary study of optimal measurement location on vibroarthrography for classification of patients with knee osteoarthritis

    PubMed Central

    Ota, Susumu; Ando, Akiko; Tozawa, Yusuke; Nakamura, Takuya; Okamoto, Shogo; Sakai, Takenobu; Hase, Kazunori

    2016-01-01

    [Purpose] The aims of the present study were to investigate the most suitable location for vibroarthrography measurements of the knee joint to distinguish a healthy knee from knee osteoarthritis using Wavelet transform analysis. [Subjects and Methods] Participants were 16 healthy females and 17 females with severe knee osteoarthritis. Vibroarthrography signals were measured on the medial and lateral epicondyles, mid-patella, and tibia using stethoscopes with a microphone while subjects stood up from a seated position. Frequency and knee flexion angles at the peak wavelet coefficient were obtained. [Results] Peak wavelet coefficients at the lateral condyle and tibia were significantly higher in patients with knee osteoarthritis than in the control group. Knee joint angles at the peak wavelet coefficient were smaller (more extension) in the osteoarthritis group compared to the control group. The area under the receiver operating characteristic curve on tibia assessment with the frequency and knee flexion angles was higher than at the other measurement locations (both area under the curve: 0.86). [Conclusion] The tibia is the most suitable location for classifying knee osteoarthritis based on vibroarthrography signals. PMID:27821959

  13. Apollo total knee replacements in University Malaya Medical Centre: a short-term outcome.

    PubMed

    Abbas, A A; Merican, A M; Kwan, M K; Mohamad, J A

    2006-02-01

    Total knee arthroplasty is the most preferred option for treatment of severe osteoarthritis of the knee. We report the short-term outcome of 48 total knee replacements in 31 patients utilizing the Apollo Total Knee System after an average follow-up of 48 months (range 15 to 70 months). Records of all patients who underwent TKA using Apollo Total Knee System were retrospectively reviewed. Functional outcome was evaluated using visual analogue scale for pain rating and the Oxford 12-item questionnaire. Postoperative radiographs of the replaced knees were assessed by using the Knee Society Total Knee Arthroplasty Roentgenographic Evaluation and Scoring System. Degenerative osteoarthritis was the commonest indication for TKA. The average patient's age was 63.7 years (range, 30-77 years). The mean visual analogue scale for pre- and post-operative pain was eight and zero respectively. The mean Oxford 12-item questionnaire score pre- and post-operatively was 44.8 and 16.5 respectively. Patient satisfaction was notable in 98% of the cases with an average improvement in arc of flexion of 111 degrees. There were four failures; deep infection (one) and aseptic loosening (three) giving rise to a 94% implant survivor. The short-term results of this series is comparable with or better than a number of outcome studies of the Apollo Knee System or other implants of similar design.

  14. Patient Self-Assessed Passive Range of Motion of the Knee Cannot Replace Health Professional Measurements.

    PubMed

    Borgbjerg, Jens; Madsen, Frank; Odgaard, Anders

    2017-03-01

    The purpose of this study was to investigate whether patients can accurately self-assess their knee passive range of motion (PROM). A picture-based questionnaire for patient self-assessment of knee PROM was developed and posted to patients. The self-assessed PROM from 58 patients was compared with surgeon-assessed PROM using a short-arm goniometer. Agreement between the measurement methods was calculated with the Bland-Altman method. We calculated the sensitivity and specificity of patient-assessed PROM in dichotomously detecting knee motion impairment in both flexion (≤ 100 degrees) and extension (≥ 10-degree flexion contracture). Surgeon- and patient-assessed knee PROM showed a mean difference (95% limits of agreement) of -2.1 degrees (-42.5 to 38.3 degrees) for flexion and -8.1 degrees (-28.8 to 12.7 degrees) for extension. The sensitivity of patient self-assessed PROM in identifying knee flexion and extension impairments was 86 and 100%, respectively, whereas its specificity was 84 and 43%, respectively. Although wide limits of agreement were observed between surgeon- and patient-assessed knee PROM, the picture-based questionnaire for patient assessment of knee ROM was found to be a valid tool for dichotomously detecting knee motion impairment in flexion (≤ 100 degrees). However, the specificity of the questionnaire for detection of knee extension impairments (≥ 10-degree flexion contracture) was low, which limits is practical utility for this purpose.

  15. Age-related changes in kinematics of the knee joint during deep squat.

    PubMed

    Fukagawa, Shingo; Leardini, Alberto; Callewaert, Barbara; Wong, Pius D; Labey, Luc; Desloovere, Kaat; Matsuda, Shuichi; Bellemans, Johan

    2012-06-01

    Researchers frequently use the deep knee squat as a motor task in order to evaluate the kinematic performance after total knee arthroplasty. Many authors reported about the kinematics of a normal squatting motion, however, little is known on what the influence of aging is. Twenty-two healthy volunteers in various age groups (range 21-75 years) performed a deep knee squat activity while undergoing motion analysis using an optical tracking system. The influence of aging was evaluated with respect to kinematics of the trunk, hip, knee and ankle joints. Older subjects required significantly more time to perform a deep squat, especially during the descending phase. They also had more knee abduction and delayed peak knee flexion. Older subjects were slower in descend than ascend during the squat. Although older subjects had a trend towards less maximal flexion and less internal rotation of the knee compared to younger subjects, this difference was not significant. Older subjects also showed a trend towards more forward leaning of the trunk, resulting in increased hip flexion and anterior thoracic tilt. This study confirmed that some aspects of squat kinematics vary significantly with age, and that the basic methodology employed here can successfully detect these age-related trends. Older subjects had more abduction of the knee joint, and this may indicate the load distribution of the medial and lateral condyles could be different amongst ages. Age-matched control data are therefore required whenever the performance of an implant is evaluated during a deep knee squat.

  16. Proprioceptive impairments associated with knee osteoarthritis are not generalized to the ankle and elbow joints.

    PubMed

    Shanahan, Camille J; Wrigley, Tim V; Farrell, Michael J; Bennell, Kim L; Hodges, Paul W

    2015-06-01

    The mechanisms for proprioceptive changes associated with knee osteoarthritis (OA) remain elusive. Observations of proprioceptive changes in both affected knees and other joints imply more generalized mechanisms for proprioceptive impairment. However, evidence for a generalized effect remains controversial. This study examined whether joint repositioning proprioceptive deficits are localized to the diseased joint (knee) or generalized across other joints (elbow and ankle) in people with knee OA. Thirty individuals with right knee OA (17 female, 66±7 [mean±SD] years) of moderate/severe radiographic disease severity and 30 healthy asymptomatic controls of comparable age (17 female, 65±8years) performed active joint repositioning tests of the knee, ankle and elbow in randomised order in supine. Participants with knee OA had a larger relative error for joint repositioning of the knee than the controls (OA: 2.7±2.1°, control: 1.6±1.7°, p=.03). Relative error did not differ between groups for the ankle (OA: 2.2±2.5°, control: 1.9±1.3°, p=.50) or elbow (OA: 2.5±3.3°, control: 2.9±2.8°, p=.58). These results are consistent with a mechanism for proprioceptive change that is localized to the knee joint. This could be mediated by problems with mechanoreceptors, processing/relay of somatosensory input to higher centers, or joint-specific interference with cognitive processes by pain.

  17. Wear-simulation analysis of rotating-platform mobile-bearing knees.

    PubMed

    Fisher, John; McEwen, Hannah; Tipper, Joanne; Jennings, Louise; Farrar, Richard; Stone, Martin; Ingham, Eileen

    2006-09-01

    The wear and wear debris from rotating-platform mobile-bearing knees and fixed-bearing knees were compared in knee joint-simulator studies. The wear rate of the fixed-bearing knees was found to increase as the kinematics were increased because of an increase in internal-external rotation and an increase in anterorposterior (AP) translation. The wear rate of the rotating-platform mobile-bearing knees was found to be significantly lower than that of the fixed-bearing knees. The rotating-platform mobile-bearing knee was able to decouple the complex kinematics to pure rotation at the inferior tibial articulating surface and linear flexion-extension and AP sliding at the superior femoral articulating interface, substantially reducing cross-shear and wear. No difference was found in the wear debris between the rotating-platform and fixed-bearing knees. This resulted in a substantially reduced functional biological activity or osteolytic potential for the rotating-platform mobile-bearing knees due to the lower wear rates.

  18. Kinematic Analysis of Gait Following Intra-articular Corticosteroid Injection into the Knee Joint with an Acute Exacerbation of Arthritis

    PubMed Central

    Mehta, Saurabh; Szturm, Tony; El-Gabalawy, Hani S.

    2011-01-01

    ABSTRACT Purpose: The objective of this study was to examine the effects of intra-articular corticosteroid injection (ICI) on ipsilateral knee flexion/extension, ankle dorsiflexion/plantarflexion (DF/PF), and hip abduction/adduction (abd/add) during stance phase in people with an acute exacerbation of rheumatoid arthritis (RA) of the knee joint. The study also assessed the effects of ICI on spatiotemporal parameters of gait and functional status in this group. Methods: Nine people with an exacerbation of RA of the knee were recruited. Kinematic and spatiotemporal gait parameters were obtained for each participant. Knee-related functional status was assessed using the Knee injury and Osteoarthritis Outcome Score (KOOS). Spatiotemporal gait parameters and joint angles (knee flexion, ankle DF/PF, hip abd/add) of the affected side were compared pre- and post-ICI. Results: Data for eight people were available for analysis. Median values for knee flexion and ankle PF increased significantly following ICI. Gait parameters of cadence, velocity, bilateral stride length, bilateral step length, step width, double-support percentage, and step time on the affected side also showed improvement. Pain and knee-related functional status as measured by the KOOS showed improvement. Conclusions: This study demonstrated a beneficial short-term effect of ICI on knee-joint movements, gait parameters, and knee-related functional status in people with acute exacerbation of RA of the knee. PMID:22942516

  19. Immobilisation of the knee and ankle and its impact on drivers' braking times: a driving simulator study.

    PubMed

    Waton, A; Kakwani, R; Cooke, N J; Litchfield, D; Kok, D; Middleton, H; Irwin, L

    2011-07-01

    The purpose of this study was to investigate the effects of right leg restriction at the knee, ankle or both, on a driver's braking times. Previous studies have not investigated the effects of knee restriction on braking performance. A total of 23 healthy drivers performed a series of emergency braking tests in a driving simulator in either an above-knee plaster cast, a below-knee cast, or in a knee brace with an increasing range of restriction. The study showed that total braking reaction time was significantly longer when wearing an above-knee plaster cast, a below-knee plaster cast or a knee brace fixed at 0°, compared with braking normally (p < 0.001). Increases in the time taken to move the foot from the accelerator to the brake accounted for some of the increase in the total braking reaction time. Unexpectedly, thinking time also increased with the level of restriction (p < 0.001). The increase in braking time with an above-knee plaster cast in this study would increase the stopping distance at 30 miles per hour by almost 3 m. These results suggest that all patients wearing any lower-limb plaster cast or knee brace are significantly impaired in their ability to perform an emergency stop. We suggest changes to the legislation to prevent patients from driving with lower-limb plaster casts or knee braces.

  20. Elastic properties of an intact and ACL-ruptured knee joint: measurement, mathematical modelling, and haptic rendering.

    PubMed

    Frey, Martin; Riener, Robert; Michas, Christian; Regenfelder, Felix; Burgkart, Rainer

    2006-01-01

    An analytical, dynamic model of the human knee joint has been developed to simulate the unloaded knee joint behaviour in 6 degrees of freedom. It is based on extensive robot-based measurements of the elastic properties of a human cadaver knee joint. The measured data are compared with data from the literature to ensure that a proper database for modelling is used. The analytical modelling of the passive elastic joint properties is done with Local Linear Model Trees. The deduced knee joint model incorporates passive elastic properties of the internal knee joint structures, passive elastic muscle forces, damping forces, gravitational forces, and external forces. There are two sets of parameters, one simulating the movement of the intact knee joint, and a second simulating the knee joint with ruptured anterior cruciate ligament. The dynamic model can be easily processed in real-time. It is implemented in the haptic display of the Munich Knee Joint Simulator (MKS), which enables a person to move a plastic leg driven by a robot manipulator and feel the simulated knee joint force. Orthopaedic physicians judged the performance of the dynamic knee joint model by executing physical knee joint tests at the MKS.

  1. Oculoscopy in Rabbits and Rodents.

    PubMed

    Jekl, Vladimir; Hauptman, Karel; Knotek, Zdenek

    2015-09-01

    Ophthalmic diseases are common in rabbits and rodents. Fast and definitive diagnosis is imperative for successful treatment of ocular diseases. Ophthalmic examination in rabbits and rodents can be challenging. Oculoscopy offers great magnification for the examination of the ocular structures in such animals, including the evaluation of cornea, anterior eye chamber, limbus, iris, lens, and retina. To date, oculoscopy has been described only sporadically and/or under experimental conditions. This article describes the oculoscopy technique, normal and abnormal ocular findings, and the most common eye disorders diagnosed with the aid of endoscopy in rabbits and rodents.

  2. Effect of low-power helium-neon laser irradiation on 13-week immobilized articular cartilage of rabbits.

    PubMed

    Bayat, Mohammad; Ansari, Anayatallah; Hekmat, Hossien

    2004-09-01

    Influence of low-power (632.8 nm, Helium-Neon, 13 J/cm2, three times a week) laser on 13-week immobilized articular cartilage was examined with rabbits knee model. Number of chondrocytes and depth of articular cartilage of experimental group were significantly higher than those of sham irradiated group. Surface morphology of sham-irradiated group had rough prominences, fibrillation and lacunae but surface morphology of experimental group had more similarities to control group than to sham irradiated group. There were marked differences between ultrastructure features of control group and experimental group in comparison with sham irradiated group. Low-power Helium-Neon laser irradiation on 13-week immobilized knee joints of rabbits neutrilized adverse effects of immobilization on articular cartilage.

  3. Evaluation of haematological, biochemical and histopathological parameters of transgenic rabbits.

    PubMed

    Jurcik, R; Suvegova, K; Hanusova, E; Massanyi, P; Ryban, L; Chrenek, P

    2007-11-01

    The aim of our study was to compare the hFVIII mRNA expression in different organs, pathological changes and selected haematological and biochemical blood parameters between transgenic and non-transgenic rabbits from F3 generation. Selected physiological parameters of 3- to 4-month-old transgenic rabbits from F3 generation carrying human factor VIII gene (hFVIII) were analysed and compared with those of non-transgenic ones. Before slaughtering, the blood for haematological and biochemical analysis was taken from the central ear artery. Pathological and histological examination of vital organs and RT-PCR analysis of several tissue organs of transgenic and non-transgenic animals were performed after slaughtering. Except for the mammary gland tissue, slight hfVIII mRNA expression in the spleen, lung and brain and none expression in the liver, kidney, skeletal muscle and heart of rabbits were recorded. pathological examination of vital organs showed some pathological changes in both transgenic and non-transgenic rabbits which were confirmed by histological qualitative evaluations. Statistically significant lower values of blood haemoglobin in blood of transgenic (11.86+/-0.86) animals compared with non-transgenic (12.41+/-1.02, P<0.05) ones and lower parameters of HCT (39.22+/-2.44 versus 40.89+/-2.26, P<0.01) in blood of transgenic rabbits were observed. Parameters of WBC, RBC and PLT showed no significant differences between the analysed groups. All biochemical serum parameters of transgenic rabbits were higher in comparison with non-transgenic ones. Significant differences were found in the concentration of the urea, AST and GMT between transgenic and non-transgenic animals (P<0.001) and in the total protein content, the difference was significant at P<0.05. In conclusion, our results showed that no considerable impact on the general health was found in transgenic rabbits.

  4. Anterior Knee Pain (Chondromalacia Patellae).

    ERIC Educational Resources Information Center

    Garrick, James G.

    1989-01-01

    This article presents a pragmatic approach to the definition, diagnosis, and management of anterior knee pain. Symptoms and treatment are described. Emphasis is on active involvement of the patient in the rehabilitation exercise program. (IAH)

  5. Bowlegs and Knock-Knees

    MedlinePlus

    ... Infections Learning Disabilities Obesity Orthopedic Prevention Sexually Transmitted ... and Knock-Knees Page Content Article Body Toddlers’ legs often have a bowed appearance. In fact, many children have bowing of the ...

  6. Structural changes in the lengthened rabbit muscle

    PubMed Central

    Berki, Sándor; Shisha, Tamás; Kiss, Sándor; Szőke, György

    2008-01-01

    This study evaluated the histological changes in muscle tissue after limb lengthening in skeletally mature and immature rabbits and assessed the most vulnerable level of striated muscle. Twenty-three male domestic white rabbits, divided into six groups, were operated on and different lengthening protocols were used in the mature and immature rabbits. The histopathological changes were analysed by a semi-quantitative method according to the scoring system of Lee et al. (Acta Orthop Scand 64(6):688–692, 1993). After the evaluation of the five main degenerative parameters (muscle atrophy, muscle nuclei internalisation, degeneration of the muscle fibre, perimysial and endomysial fibrosis, haematomas), it is evident that the adults lengthened at a rate of 1.6 mm/day showed more degenerative changes than those lengthened at 0.8 mm/day. The adult 1.6 mm/day lengthened group presented significantly higher damage in the muscle and lower regenerative signs compared with the young 1.6 mm/day lengthened group, according to the summarised degenerative scores. PMID:18259704

  7. Three Variations in Rabbit Angiographic Stroke Models

    PubMed Central

    Culp, William C.; Woods, Sean D.; Brown, Aliza T.; Lowery, John D.; Hennings, Leah J.; Skinner, Robert D.; Borrelli, Michael J.; Roberson, Paula K.

    2012-01-01

    Purpose To develop angiographic models of embolic stroke in the rabbit using pre-formed clot or microspheres to model clinical situations ranging from transient ischemic events to severe ischemic stroke. Materials and Methods New Zealand White rabbits (N=151) received angiographic access to the internal carotid artery (ICA) from a femoral approach. Variations of emboli type and quantity of emboli were tested by injection into the ICA. These included fresh clots (1.0-mm length, 3–6 h), larger aged clots (4.0-mm length, 3 days), and 2 or 3 insoluble microspheres (700–900 μm). Neurological assessment scores (NAS) were based on motor, sensory, balance, and reflex measures. Rabbits were euthanized at 4, 7, or 24 hours after embolization, and infarct volume was measured as a percent of total brain volume using 2,3,5-triphenyltetrazolium chloride (TTC). Results Infarct volume percent at 24 hours after stroke was lower for rabbits embolized with fresh clot (0.45% ± 0.14%), compared with aged clot (3.52% ± 1.31%) and insoluble microspheres (3.39% ± 1.04%). Overall NAS (including posterior vessel occlusions) were positively correlated to infarct volume percent measurements in the fresh clot (r=0.50), aged clot (r=0.65) and microsphere (r=0.62) models (p<0.001). Conclusion The three basic angiographic stroke models may be similar to human transient ischemic attacks (TIA) (fresh clot), major strokes that can be thrombolysed (aged clot), or major strokes with insoluble emboli such as atheromata (microspheres). Model selection can be tailored to specific research needs. PMID:23142182

  8. Does bracing influence brain activity during knee movement: an fMRI study.

    PubMed

    Thijs, Youri; Vingerhoets, Guy; Pattyn, Els; Rombaut, Lies; Witvrouw, Erik

    2010-08-01

    Studies have shown that proprioceptive inputs during active and passive arm movements are processed in the primary and secondary somatosensory cortex and supplementary motor area of the brain. At which level of the central nervous system proprioceptive signals coming from the knee are regulated remains to be elucidated. In order to investigate whether there is a detectable difference in brain activity when various proprioceptive inputs are exerted at the knee, functional magnetic resonance imaging (fMRI) was used. fMRI in 13 healthy, right leg-dominant female volunteers compared brain activation during flexion-extension movements of the right knee under three different conditions: with application of a tight knee brace, with application of a moderate tight knee sleeve, and without application of a brace or sleeve. Brain activation was detected in the primary sensorimotor cortex (left and right paracentral lobule) and in the left superior parietal lobule of the brain. There was a significantly higher level of brain activation with the application of the brace and sleeve, respectively, compared to the condition without a brace or sleeve. A significantly higher cortical activation was also seen when comparing the braced condition with the condition when a sleeve was applied. The results suggest that peripheral proprioceptive input to the knee joint by means of a brace or sleeve seems to influence brain activity during knee movement. The results of this study also show that the intensity of brain activation during knee movement can be influenced by the intensity of proprioceptive stimulation at the joint.

  9. Biomechanical comparison of frontal plane knee joint moment arms during normal and Tai Chi walking.

    PubMed

    Jagodinsky, Adam; Fox, John; Decoux, Brandi; Weimar, Wendi; Liu, Wei

    2015-09-01

    [Purpose] Medial knee osteoarthritis, a degenerative joint disease, affects adults. The external knee adduction moment, a surrogate knee-loading measure, has clinical implications for knee osteoarthritis patients. Tai Chi is a promising intervention for pain alleviation in knee osteoarthritis; however, the characteristics of external knee adduction moment during Tai Chi have not been established. [Subjects and Methods] During normal and Tai Chi walking, a gait analysis was performed to compare the external knee adduction moment moment-arm characteristics and paired t-tests to compare moment-arm magnitudes. [Results] A significant difference was observed in the average lateral direction of moment-arm magnitude during Tai Chi walking (-0.0239 ± 0.011 m) compared to that during normal walking (-0.0057 ± 0.004 m). No significant difference was found between conditions in average medial direction of moment-arm magnitude (normal walking: 0.0143 ± 0.010 m; Tai Chi walking: 0.0098 ± 0.014 m). [Conclusion] Tai Chi walking produced a larger peak lateral moment-arm value than normal walking during the stance phase, whereas Tai Chi walking and normal walking peak medial moment-arm values were similar, suggesting that medial knee joint loading may be avoided during Tai Chi walking.

  10. Simple verbal instruction improves knee biomechanics during landing in female athletes.

    PubMed

    Milner, Clare E; Fairbrother, Jeffrey T; Srivatsan, Abhaya; Zhang, Songning

    2012-08-01

    Knee injuries are highly prevalent in athletic populations, particularly among female athletes. Many of these injuries occur during landing from a jump. Various comprehensive knee injury prevention programs have been developed to date. However, there is a need to determine which components of these programs contribute directly to changes in knee biomechanics. Therefore, the purpose of this study was to investigate the immediate effect of three different simple verbal instructions on knee biomechanics during landing in adult female recreational athletes. Three-dimensional kinematic and kinetic analysis of landing from a countermovement jump was conducted in a counterbalanced cross-over repeated measures design. Results indicated that the instruction to land with equal weight distribution reduced the asymmetry of peak vertical ground reaction force compared to the control condition. The instruction to land softly reduced peak vertical ground reaction force and increased peak knee flexion compared to the control condition. The instruction to land with knees over toes increased peak knee flexion compared to the control condition. These findings indicate that verbal instruction may be a key component of the effects seen in previous research studies that have investigated the benefits of more complex training programs designed to reduce knee injury risk in female athletes.

  11. Knee Brace Would Lock And Unlock Automatically

    NASA Technical Reports Server (NTRS)

    Myers, Neill; Forbes, John; Shadoan, Mike; Baker, Kevin

    1995-01-01

    Proposed knee brace designed to aid rehabilitation of person who suffered some muscle damage in leg. Not limited to locking in straight-leg position and, instead, locks at any bend angle. Does not prevent knee from bearing weight. Instead, knee brace allows knee to bear weight and locks only when foot and lower leg bear weight. Thus, brace prevents flexion that wearer desired to prevent but could not prevent because of weakened muscles. Knee bends freely to exercise knee-related muscles. Knee brace strapped at upper end to leg above knee, and anchored at lower end by stirrup under foot. Joint mechanism (identical mechanisms used in left and right assemblies) allows knee joint to flex freely except when weight applied to heel.

  12. The Nature of Age-Related Differences in Knee Function during Walking: Implication for the Development of Knee Osteoarthritis

    PubMed Central

    Boyer, Katherine A.; Andriacchi, Thomas P.

    2016-01-01

    Background Changes in knee kinematics have been identified in the early stages of osteoarthritis (OA). However, there is a paucity of information on the nature of kinematic change that occur with aging prior to the development of OA, This study applied a robust statistical method (Principal Component Analysis) to test the hypothesis that coupling between primary (flexion) and secondary (anterior-posterior translation, internal-external rotation) joint motions in walking would differ for age groupings of healthy subjects. Methods Seventy-four healthy participants divided into three groups with mean ages of 24 ± 2.3 years (younger), 48 ± 4.7years (middle-age) and 64 ± 2.4 years (older) were examined. Principal Component Analysis was used to characterize and statistically compare the patterns of knee joint movement and their relationships in walking. Results There were significant differences between the younger group and both the middle-age and older groups in the knee frontal plane angle and the coupling between knee flexion (PC1, p≤0.04) and the relative magnitudes of secondary plane motions in early and late stance (PC3, p<0.01). Two additional principal components (PC2, p = 0.03 and PC5, p<0.01) described differences in early stance knee flexion and relationship with secondary plane motion through-out stance for the older compared with middle-age group. Conclusions It appears there are changes in knee kinematics that occur with aging. The kinematic differences were identified for middle-aged as well as older adults suggesting midlife changes in neuromuscular physiology or behavior may have important consequences. These kinematic measures offer the potential to identify early markers for the risk of developing knee OA with aging. PMID:27973527

  13. Analysis of Knee Joint Line Obliquity after High Tibial Osteotomy.

    PubMed

    Oh, Kwang-Jun; Ko, Young Bong; Bae, Ji Hoon; Yoon, Suk Tae; Kim, Jae Gyoon

    2016-11-01

    The aim of this study was to evaluate which lower extremity alignment (knee and ankle joint) parameters affect knee joint line obliquity (KJLO) in the coronal plane after open wedge high tibial osteotomy (OWHTO). Overall, 69 knees of patients that underwent OWHTO were evaluated using radiographs obtained preoperatively and from 6 weeks to 3 months postoperatively. We measured multiple parameters of knee and ankle joint alignment (hip-knee-ankle angle [HKA], joint line height [JLH], posterior tibial slope [PS], femoral condyle-tibial plateau angle [FCTP], medial proximal tibial angle [MPTA], mechanical lateral distal femoral angle [mLDFA], KJLO, talar tilt angle [TTA], ankle joint obliquity [AJO], and the lateral distal tibial ground surface angle [LDTGA]; preoperative [-pre], postoperative [-post], and the difference between -pre and -post values [-Δ]). We categorized patients into two groups according to the KJLO-post value (the normal group [within ± 4 degrees, 56 knees] and the abnormal group [greater than ± 4 degrees, 13 knees]), and compared their -pre parameters. Multiple logistic regression analysis was used to examine the contribution of the -pre parameters to abnormal KJLO-post. The mean HKA-Δ (-9.4 ± 4.7 degrees) was larger than the mean KJLO-Δ (-2.1 ± 3.2 degrees). The knee joint alignment parameters (the HKA-pre, FCTP-pre) differed significantly between the two groups (p < 0.05). In addition, the HKA-pre (odds ratio [OR] = 1.27, p = 0.006) and FCTP-pre (OR = 2.13, p = 0.006) were significant predictors of abnormal KJLO-post. However, -pre ankle joint parameters (TTA, AJO, and LDTGA) did not differ significantly between the two groups and were not significantly associated with the abnormal KJLO-post. The -pre knee joint alignment and knee joint convergence angle evaluated by HKA-pre and FCTP-pre angle, respectively, were significant predictors of abnormal KJLO after OWHTO. However, -pre ankle joint parameters

  14. [Congenital knee dislocation: case report].

    PubMed

    Arvinius, C; Luque, R; Díaz-Ceacero, C; Marco, F

    2016-01-01

    Congenital knee dislocation is an infrequent condition with unknown etiology. In some cases it occurs as an isolated condition, while in others it coexists with associated conditions or syndromes. The treatment of congenital knee dislocation is driven by the severity and flexibility of the deformity. The literature includes from serial casting or the Pavlik harness to quadriceps tendon plasty or femoral osteotomies. We report herein the case of a congenital dislocation treated with serial casting with a good outcome.

  15. New Zealand white rabbit as a nonsurgical experimental model for Salmonella enterica gastroenteritis.

    PubMed

    Hanes, D E; Robl, M G; Schneider, C M; Burr, D H

    2001-10-01

    Rabbits orally challenged with Salmonella enterica developed a dose-dependent diarrheal disease comparable to human salmonellosis. Viable Salmonella organisms recovered from the intestine and deep tissues indicate local and systemic infections. Therefore, results show that the rabbit can be used as a model for diarrheal disease and sequelae associated with salmonellosis.

  16. Gait analysis of elderly women after total knee arthroplasty.

    PubMed

    Lee, Aenon; Park, Junhyuck; Lee, Seungwon

    2015-03-01

    [Purpose] The purpose of this study was to investigate ability and muscle activities of elderly women after total knee arthroplasty (TKA) and compare them with those of healthy ones. [Subjects and Methods] Fifteen female patients with TKA due to advanced degenerative arthritis of the measured on knee joint and 19 healthy elderly females participated. Tibiofemoral angles of TKA patients were using a gait analysis system anterioposterior X-rays of the weight-bearing knee. The knee flexion angle and gait parameters were measured. Muscle activities and prolongation time were EMG system. The gait of the treated limb of each participant was evaluated in three consecutive trials at fast speed and comfortable speed. [Results] The knee flexion angle %stance phase, stride length, step length, speed, cadence, and gait cycle significantly decreased at both the fast speed and comfortable speeds, and the onset and duration time of rectus femoris activity was significantly increased at the comfortable speed in the TKA group. [Conclusion] In conclusion, elderly women who received TKA showed decreased gait ability and muscle activity compared to the healthy elderly women.

  17. Gait analysis of elderly women after total knee arthroplasty

    PubMed Central

    Lee, Aenon; Park, Junhyuck; Lee, Seungwon

    2015-01-01

    [Purpose] The purpose of this study was to investigate ability and muscle activities of elderly women after total knee arthroplasty (TKA) and compare them with those of healthy ones. [Subjects and Methods] Fifteen female patients with TKA due to advanced degenerative arthritis of the measured on knee joint and 19 healthy elderly females participated. Tibiofemoral angles of TKA patients were using a gait analysis system anterioposterior X-rays of the weight-bearing knee. The knee flexion angle and gait parameters were measured. Muscle activities and prolongation time were EMG system. The gait of the treated limb of each participant was evaluated in three consecutive trials at fast speed and comfortable speed. [Results] The knee flexion angle %stance phase, stride length, step length, speed, cadence, and gait cycle significantly decreased at both the fast speed and comfortable speeds, and the onset and duration time of rectus femoris activity was significantly increased at the comfortable speed in the TKA group. [Conclusion] In conclusion, elderly women who received TKA showed decreased gait ability and muscle activity compared to the healthy elderly women. PMID:25931687

  18. The cottontail rabbits of Virginia

    USGS Publications Warehouse

    Llewellyn, L.M.; Handley, C.O.

    1945-01-01

    Five races of cottontail rabbits belonging to three species occur in Virginia. One of them, the Mearns cottontail (Sylvilagus floridanus mearnsi), is reported here for the first time. It occurs in six southwestern counties of the state, while the eastern cottontail (S. f. mallurus) occurs in the remainder of the state with the exception of Smith and Fishermans islands off the eastern coast of Cape Charles, where it is replaced by Hitchens cottontail (S. f. hitchensi). The New England cottontail (S. transitionalis) is found on the higher mountain peaks, above 3000 feet, and the swamp rabbit (S. palustris) occurs in the Dismal Swamp region of southeastern Virginia.....The height of the breeding season for the eastern cottontail in Virginia is March and April, but breeding continues through the entire year except in December and January. The average litter size based on embryo counts was 4.7. The sex ratio of 234 specimens from all parts of the state, taken mostly in the December to February period, was 53 males to 47 females. That of a group of 145 rabbits live-trapped at Blacksburg during February and Marchwas 58 males to 42 females. The figures show that males are more active than females during the winter months, and therefore are more easily taken then....In transplanting cottontails from one section of the state to another, it is recommended that only cottontails of the same race as those originally present in the region being restocked be released there....Tularemia is not a common disease among rabbits in Virginia, but the rabbit ticks are often carriers of the disease and may transmit it to rabbits. Rabbit ticks are also found to be carriers of Rocky Mountain fever and American Q. fever. After the ticks drop off the rabbits to hibernate in the ground, which is likely to occur during mid-winter in Virginia, there is relatively little danger of humans contracting tularemia by contact with rabbits. Present laws in Virginia which prohibit rabbit hunting until the

  19. Tibia valga morphology in osteoarthritic knees: importance of preoperative full limb radiographs in total knee arthroplasty.

    PubMed

    Alghamdi, Ahmed; Rahmé, Michel; Lavigne, Martin; Massé, Vincent; Vendittoli, Pascal-André

    2014-08-01

    Osteoarthritis of the knee is associated with deformities of the lower limb. Tibia valga is a contributing factor to lower limb alignment in valgus knees. We evaluated 97 valgus knees and 100 varus knees. Long-leg films were taken in weight bearing with both knees in full extension. For valgus knees, 52 knees (53%) had a tibia valga deformity. Average tibia valgus deformation was 5.0°. For varus knees, there was only 1 case of tibia valga (1%), with a deformation of 2.5°. The aim of this study was to assess the prevalence of primary tibia valga in valgus and varus knees and understand how it affects our approach to total knee arthroplasty (TKA). We recommend having full-leg length films when planning for TKA in valgus knees.

  20. Prolonged oral cyanide effects on feed intake, growth rate and blood parameters in rabbits.

    PubMed

    Avais, Muhammad; Khan, Muhammad Sarwar; Khan, Muhammad Arif; Ashraf, Kamran; Khan, Jawaria Ali; Hameed, Sajid

    2014-07-01

    Twelve adult rabbits bred locally were divided into two equal groups of 6; experimental and control groups. Rabbits in the experimental group were orally dosed with KCN at 3mg/kg body weight for 40 consecutive days. Members in control group were given placebo (distilled water) for the same period. Animals in both groups were offered feed at 90gm/kg/day while ample drinking water was available ad lib. Feed consumption and body weight of rabbits in both the groups were recorded. Blood samples were also drawn to determine various hematological parameters. Statistical analysis revealed a non-significant difference of total and daily feed intakes in rabbits of experimental and control groups. Whereas the feed efficiency of rabbits in the experimental group were significantly reduced (P<0.05) compared to controls. Likewise a significant decrease in body weight gain of rabbits in experimental group (P<0.05) was observed. A non-significant difference (P>0.05) was observed in leukocyte count, differential leukocyte count and platelets of rabbits in both the groups. Erythrocyte count, hemoglobin concentration, packed cell volume and mean corpuscular hemoglobin were significantly decreased in treated rabbits. It was concluded that chronic cyanide intake had a deleterious effect on feed efficiency, growth rate and blood components of rabbits.

  1. Non-Sagittal Knee Joint Kinematics and Kinetics during Gait on Level and Sloped Grounds with Unicompartmental and Total Knee Arthroplasty Patients.

    PubMed

    Komnik, Igor; Peters, Markus; Funken, Johannes; David, Sina; Weiss, Stefan; Potthast, Wolfgang

    2016-01-01

    After knee arthroplasty (KA) surgery, patients experience abnormal kinematics and kinetics during numerous activities of daily living. Biomechanical investigations have focused primarily on level walking, whereas walking on sloped surfaces, which is stated to affect knee kinematics and kinetics considerably, has been neglected to this day. This study aimed to analyze over-ground walking on level and sloped surfaces with a special focus on transverse and frontal plane knee kinematics and kinetics in patients with KA. A three-dimensional (3D) motion analysis was performed by means of optoelectronic stereophogrammetry 1.8 ± 0.4 years following total knee arthroplasty (TKA) and unicompartmental arthroplasty surgery (UKA). AnyBody™ Modeling System was used to conduct inverse dynamics. The TKA group negotiated the decline walking task with reduced peak knee internal rotation angles compared with a healthy control group (CG). First-peak knee adduction moments were diminished by 27% (TKA group) and 22% (UKA group) compared with the CG during decline walking. No significant differences were detected between the TKA and UKA groups, regardless of the locomotion task. Decline walking exposed apparently more abnormal knee frontal and transverse plane adjustments in KA patients than level walking compared with the CG. Hence, walking on sloped surfaces should be included in further motion analysis studies investigating KA patients in order to detect potential deficits that might be not obvious during level walking.

  2. Non-Sagittal Knee Joint Kinematics and Kinetics during Gait on Level and Sloped Grounds with Unicompartmental and Total Knee Arthroplasty Patients

    PubMed Central

    Komnik, Igor; David, Sina; Weiss, Stefan; Potthast, Wolfgang

    2016-01-01

    After knee arthroplasty (KA) surgery, patients experience abnormal kinematics and kinetics during numerous activities of daily living. Biomechanical investigations have focused primarily on level walking, whereas walking on sloped surfaces, which is stated to affect knee kinematics and kinetics considerably, has been neglected to this day. This study aimed to analyze over-ground walking on level and sloped surfaces with a special focus on transverse and frontal plane knee kinematics and kinetics in patients with KA. A three-dimensional (3D) motion analysis was performed by means of optoelectronic stereophogrammetry 1.8 ± 0.4 years following total knee arthroplasty (TKA) and unicompartmental arthroplasty surgery (UKA). AnyBody™ Modeling System was used to conduct inverse dynamics. The TKA group negotiated the decline walking task with reduced peak knee internal rotation angles compared with a healthy control group (CG). First-peak knee adduction moments were diminished by 27% (TKA group) and 22% (UKA group) compared with the CG during decline walking. No significant differences were detected between the TKA and UKA groups, regardless of the locomotion task. Decline walking exposed apparently more abnormal knee frontal and transverse plane adjustments in KA patients than level walking compared with the CG. Hence, walking on sloped surfaces should be included in further motion analysis studies investigating KA patients in order to detect potential deficits that might be not obvious during level walking. PMID:28002437

  3. New models of chronic synovitis in rabbits induced by mycoplasmas: microbiological, histopathological, and immunological observations on rabbits injected with Mycoplasma arthritidis and Mycoplasma pulmonis.

    PubMed Central

    Cole, B C; Griffiths, M M; Eichwald, E J; Ward, J R

    1977-01-01

    A dose-dependent chronic synovitis was induced in rabbit knees after the intra-articular injection of both Mycoplasma arthritidis and Mycoplasma pulmonis. The inflammation progressed from an initial acute phase at 1 week characterized by edema, infiltration of the synovium with monocytes and heterophils, and desquamation of lining cells, to a more chronic phase at 1 and 3 months, in which villus hyperplasia, lymph "nodules," mononuclear cell infiltration, fibroplasia, and collagen deposition were prominent. With one exception, mycoplasmas could no longer be cultivated from the joints 1 month postinoculation. Both mycoplasma species evoked a humoral antibody response that was more marked in synovial fluids than in peripheral blood. A cell-mediated immune reaction, as evidence by enhanced uptake by [3H]thymidine by sensitized blood, spleen, or node lymphocytes in the presence of homologous antigen, was detected only in rabbits injected with M. pulmonis. Lymphocytes taken from arthritic rabbits were no more cytotoxic toward synovial cells derived from normal or arthritic rabbits than were normal lymphocytes. The models of synovitis described in this study offer a convenient probe for determining the mechanisms of mycoplasma-induced inflammation, since they require only a single injection of the initiating agent and, in addition, utilize an animal host large enough for detailed investigation into the nature of mycoplasma/synovium interactions. Images PMID:873616

  4. Venous Thromboembolism After Knee Arthroscopy in Undiagnosed Familial Thrombophilia.

    PubMed

    Jetty, Vybhav; Glueck, Charles J; Freiberg, Richard A; Wang, Ping

    2016-11-01

    Venous thromboembolism is uncommon after knee arthroscopy, and there are no guidelines for thromboprophylaxis in elective routine knee arthroscopy. Preoperative evaluation of common thrombophilias should provide guidance for postarthroscopy thromboprophylaxis in otherwise healthy patients who are at high risk for venous thromboembolism. This study assessed 10 patients with venous thromboembolism after total hip or knee arthroplasty. Patients were assessed if venous thromboembolism occurred within 6 months after knee arthroscopy (n=10) or total hip or knee arthroplasty (n=21). This study assessed gene mutations (factor V Leiden, prothrombin G20210A, plasminogen activator inhibitor, methylenetetrahydrofolate reductase) and serologic thrombophilias (high levels of factors VIII and XI, homocysteine, anticardiolipin immunoglobulin G and immunoglobulin M antibodies, and lupus anticoagulant; low antigenic protein C, S, and free S; and antithrombin III deficiency). The same coagulation data were obtained for normal subjects (n=110). The major thrombophilias in the arthroscopy group were factor V Leiden heterozygosity (40%), high factor VIII level (50%), and high homocysteine (30%). The respective values in control subjects were 2% (P=.0004), 7% (P=.0011), and 5% (P=.02). When the arthroscopy group was compared with the 21 patients who had venous thromboembolism after total hip or knee arthroplasty, the sole difference was factor V Leiden heterozygosity, which was 40% vs 0%, respectively (P=.007). Although venous thromboembolism after knee arthroscopy is uncommon, to identify high-risk patients and guide postoperative thromboprophylaxis, the authors suggest routine preoperative measurement of 3 common familial thrombophilias: factor V Leiden, factor VIII, and homocysteine. [Orthopedics. 2016; 39(6):e1052-e1057.].

  5. Noninvasive Determination of Knee Cartilage Deformation During Jumping

    PubMed Central

    Filipovic, Nenad; Vulovic, Radun; Peulic, Aleksandar; Radakovic, Radivoje; Kosanic, Djordje; Ristic, Branko

    2009-01-01

    The purpose of this investigation was to use a combination of image processing, force measurements and finite element modeling to calculate deformation of the knee cartilage during jumping. Professional athletes performed jumps analyzed using a force plate and high-speed video camera system. Image processing was performed on each frame of video using a color recognition algorithm. A simplified mass-spring-damper model was utilized for determination of global force and moment on the knee. Custom software for fitting the coupling characteristics was created. Simulated results were used as input data for the finite element calculation of cartilage deformation in the athlete’s knee. Computer simulation data was compared with the average experimental ground reaction forces. The results show the three-dimensional mechanical deformation distribution inside the cartilage volume. A combination of the image recognition technology, force plate measurements and the finite element cartilage deformation in the knee may be used in the future as an effective noninvasive tool for prediction of injury during jumping. Key points Even there are many existing mathematical models of force distribution during running or jumping (Liu et al, 1998), to our knowledge there is no interdisciplinary approach where imaging processing, finite element modeling and experimental force plate system are employed. The aim is to explore noninvasive deformation in the knee cartilage during athlete’s jumping on the force plate. An original image algorithms and software were developed as well as complex mathematical models using high-performance computational power of finite element modeling together with one-dimensional dynamics model. The initial results showed cartilage deformation in the knee and future research will be focused on the methodology and more precisely determination of the stress and strain distribution in the knee cartilage during training phase of sportsman. PMID:24149600

  6. Changes in knee kinematics following total knee arthroplasty.

    PubMed

    Akbari Shandiz, Mohsen; Boulos, Paul; Saevarsson, Stefan Karl; Yoo, Sam; Miller, Stephen; Anglin, Carolyn

    2016-04-01

    Total knee arthroplasty (TKA) changes the knee joint in both intentional and unintentional, known and unknown, ways. Patellofemoral and tibiofemoral kinematics play an important role in postoperative pain, function, satisfaction and revision, yet are largely unknown. Preoperative kinematics, postoperative kinematics or changes in kinematics may help identify causes of poor clinical outcome. Patellofemoral kinematics are challenging to record since the patella is obscured by the metal femoral component in X-ray and moves under the skin. The purpose of this study was to determine the kinematic degrees of freedom having significant changes and to evaluate the variability in individual changes to allow future study of patients with poor clinical outcomes. We prospectively studied the 6 degrees of freedom patellofemoral and tibiofemoral weightbearing kinematics, tibiofemoral contact points and helical axes of rotation of nine subjects before and at least 1 year after total knee arthroplasty using clinically available computed tomography and radiographic imaging systems. Normal kinematics for healthy individuals were identified from the literature. Significant differences existed between pre-TKA and post-TKA kinematics, with the post-TKA kinematics being closer to normal. While on average the pre-total knee arthroplasty knees in this group displayed no pivoting (only translation), individually only five knees displayed this behaviour (of these, two showed lateral pivoting, one showed medial pivoting and one showed central pivoting). There was considerable variability postoperatively as well (five central, two lateral and two medial pivoting). Both preop and postop, flexion behaviour was more hinge-like medially and more rolling laterally. Helical axes were more consistent postop for this group. An inclusive understanding of the pre-TKA and post-TKA kinematics and changes in kinematics due to total knee arthroplasty could improve implant design, patient diagnosis and

  7. MRI of knee ligament injury and reconstruction.

    PubMed

    Farshad-Amacker, Nadja A; Potter, Hollis G

    2013-10-01

    Knee ligament instability may lead to meniscal and chondral damage, resulting in early osteoarthritis. Due to its superior soft tissue contrast and avoidance of harmful ionizing radiation, MRI has become the most important imaging modality for early recognition of structural defects of the knee joint. This review aims to the understanding of MRI appearances of knee ligament structures associated with knee instability, and to review the common patterns of altered knee mechanics that lead to ligament failure. Normal anatomy of the knee ligaments, pathologic conditions, and postsurgical appearances of the anterior cruciate ligament, posterior cruciate ligament, medial collateral ligament, and posterolateral corner are described.

  8. Medial unicondylar knee arthroplasty: technical pearls

    PubMed Central

    BONIFORTI, FILIPPO

    2015-01-01

    Unicondylar knee arthroplasty implantation is extremely demanding as the prosthesis needs to be integrated in the natural anatomy of the knee. It ensures the integrity of the natural knee kinematic. Some studies and registries data have shown lower success rate in comparison with total knee arthroplasty, and patient-related factors may have an impact on outcome. While, better results have been published by high volume centres. The indications for surgery should be reconsidered critically, even if medial osteoarthritis of the knee remains the most common. This article sets out the diagnostic, and surgical steps in order to fine tuning the unicompartmental replacement of the knee. PMID:26605256

  9. Shape memory alloy smart knee spacer to enhance knee functionality: model design and finite element analysis.

    PubMed

    Gautam, Arvind; Rani, A Bhargavi; Callejas, Miguel A; Acharyya, Swati Ghosh; Acharyya, Amit; Biswas, Dwaipayan; Bhandari, Vasundhra; Sharma, Paresh; Naik, Ganesh R

    2016-08-01

    In this paper we introduce Shape Memory Alloy (SMA) for designing the tibial part of Total Knee Arthroplasty (TKA) by exploiting the shape-memory and pseudo-elasticity property of the SMA (e.g. NiTi). This would eliminate the drawbacks of the state-of-the art PMMA based knee-spacer including fracture, sustainability, dislocation, tilting, translation and subluxation for tackling the Osteoarthritis especially for the aged people of 45-plus or the athletes. In this paper a Computer Aided Design (CAD) model using SolidWorks for the knee-spacer is presented based on the proposed SMA adopting the state-of-the art industry-standard geometry that is used in the PMMA based spacer design. Subsequently Ansys based Finite Element Analysis is carried out to measure and compare the performance between the proposed SMA based model with the state-of-the art PMMA ones. 81% more bending is noticed in the PMMA based spacer compared to the proposed SMA that would eventually cause fracture and tilting or translation of spacer. Permanent shape deformation of approximately 58.75% in PMMA based spacer is observed compared to recoverable 11% deformation in SMA when same load is applied on both separately.

  10. Knee Joint Contact Mechanics during Downhill Gait and its Relationship with Varus/Valgus Motion and Muscle Strength in Patients with Knee Osteoarthritis

    PubMed Central

    Farrokhi, Shawn; Voycheck, Carrie A.; Gustafson, Jonathan A.; Fitzgerald, G. Kelley; Tashman, Scott

    2015-01-01

    Objective The objective of this exploratory study was to evaluate tibiofemoral joint contact point excursions and velocities during downhill gait and assess the relationship between tibiofemoral joint contact mechanics with frontal-plane knee joint motion and lower extremity muscle weakness in patients with knee osteoarthritis (OA). Methods Dynamic stereo X-ray was used to quantify tibiofemoral joint contact mechanics and frontal-plane motion during the loading response phase of downhill gait in 11 patients with knee OA and 11 control volunteers. Quantitative testing of the quadriceps and the hip abductor muscles was also performed. Group differences in contact mechanics and frontal-plane motion excursions were compared using analysis of covariance with adjustments for body mass index. Differences in strength were compared using independent sample t-tests. Additionally, linear associations between contact mechanics with frontal-plane knee motion and muscle strength were evaluated using Pearson's correlation coefficients. Results Patients with knee OA demonstrated larger medial/lateral joint contact point excursions (p<0.02) and greater heel-strike joint contact point velocities (p<0.05) for the medial and lateral compartments compared to the control group. The peak medial/lateral joint contact point velocity of the medial compartment was also greater for patients with knee OA compared to their control counterparts (p=0.02). Additionally, patients with knee OA demonstrated significantly increased frontal-plane varus motion excursions (p<0.01) and greater quadriceps and hip abductor muscle weakness (p=0.03). In general, increased joint contact point excursions and velocities in patients with knee OA were linearly associated with greater frontal-plane varus motion excursions (p<0.04) but not with quadriceps or hip abductor strength. Conclusion Altered contact mechanics in patients with knee OA may be related to compromised frontal-plane joint stability but not with

  11. The Effect of Work Boots on Knee Mechanics and the Center of Pressure at the Knee During Static Kneeling.

    PubMed

    Tennant, Liana; Kingston, David; Chong, Helen; Acker, Stacey

    2015-10-01

    Occupational kneeling is associated with an increased risk for the development of knee osteoarthritis. Previous work studying occupational kneeling has neglected to account for the fact that in many industrial settings, workers are required to wear steel-toe work boots. Thus, the purpose of this study was to evaluate the effect of work boot wear on the center of pressure location of the ground reaction force, knee joint angle, and magnitude of the ground reaction force in a kneeling posture. Fifteen healthy males were fit with 3D motion capture markers and knelt statically over a force plate embedded in the floor. Using the tibial tuberosity as the point of reference, the center of pressure in shod condition was shifted significantly medially (on average 0.009 m [P = .005]) compared with the barefoot condition. The knee was significantly less internally rotated (shod: -12.5° vs. barefoot: -17.4° [P = .009]) and the anterior/posterior shear force was significantly greater in the shod condition (shod: 6.0% body weight vs. barefoot: 1.5% body weight [P = .002]). Therefore, wearing work boots alters the kneeling posture compared with barefoot kneeling, potentially loading different surfaces of the knee, as well as altering knee joint moments.

  12. Changes in the activity of trunk and hip extensor muscles during bridge exercises with variations in unilateral knee joint angle

    PubMed Central

    Kim, Juseung; Park, Minchul

    2016-01-01

    [Purpose] This study compared abdominal and hip extensor muscle activity during a bridge exercise with various knee joint angles. [Subjects and Methods] Twenty-two healthy male subjects performed a bridge exercise in which the knee joint angle was altered. While subjects performed the bridge exercise, external oblique, internal oblique, gluteus maximus, and semitendinosus muscle activity was measured using electromyography. [Results] The bilateral external and internal oblique muscle activity was significantly higher at 0° knee flexion compared to 120°, 90°, and 60°. The bilateral gluteus maximus muscle activity was significantly different at 0° of knee flexion compared to 120°, 90°, and 60°. The ipsilateral semitendinosus muscle activity was significantly increased at 90° and 60° of knee flexion compared to 120°, and significantly decreased at 0° knee flexion compared with 120°, 90°, and 60°. The contralateral semitendinosus muscle activity was significantly higher at 60° of knee flexion than at 120°, and significantly higher at 0° of knee flexion than at 120°, 90°, and 60°. [Conclusion] Bridge exercises performed with knee flexion less than 90° may be used to train the ipsilateral semitendinosus. Furthermore, bridge exercise performed with one leg may be used to train abdominal and hip extensor muscles. PMID:27799688

  13. [Different properties of pyruvate kinase from rabbit and hare muscles].

    PubMed

    Strumilo, S; Tylicki, A

    2015-01-01

    Some catalytic and kinetic properties of pyruvate kinase (PK, EC 2.7.1.40) isolated from the heart and skeletal muscles of rabbits and hares with a 9-16-fold purification were studied. The initial specific activity of the enzyme in hare heart homogenates was 66% and in skeletal muscles 25% as high as in respective rabbit tissues. Temperature optimums and thermostability of PK from hare tissues were higher as compared with those in rabbits. From the comparison of K(M) (S0.5) values it follows that hare skeletal muscle PK exhibits a highest affinity to phosphoenol pyruvate, but lowest to ADP, as compared with rabbit skeletal muscle PK. Moreover, PK from both hare tissues exhibits a positive kinetic cooperativity (Hill coefficient > 1.35) of the phosphoenol pyruvate and ADP binding sites. In contrast to PK from rabbit tissues, the enzyme from the hare heart and muscles PK is presented by its allosteric isoform which might by advantageous under extreme conditions of the hare's habitation.

  14. A 12-week randomized study of topical therapy with three dosages of ketoprofen in Transfersome® gel (IDEA-033) compared with the ketoprofen-free vehicle (TDT 064), in patients with osteoarthritis of the knee

    PubMed Central

    Kneer, Werner; Rother, Matthias; Mazgareanu, Stefan; Seidel, Egbert J

    2013-01-01

    Objective To evaluate the safety and efficacy of ketoprofen in Transfersome® gel (IDEA-033) in comparison with a ketoprofen-free vehicle (TDT 064) for the treatment of osteoarthritis (OA) of the knee. Methods Patients with knee OA (N = 866) were randomly assigned to receive topical IDEA-033 containing 100, 50, or 25 mg ketoprofen, or TDT 064 twice daily for 12 weeks, in a double-blind trial. The primary efficacy endpoint was the change in the Western Ontario and McMaster Universities (WOMAC®) Osteoarthritis Index pain subscale score. The coprimary efficacy endpoints were the WOMAC function subscale score and the patient global assessment of response to therapy. The secondary endpoints included the numeric pain rating for the first 14 days of treatment and the Outcome Measures in Rheumatology (OMERACT)-Osteoarthritis Research Society International (OARSI) responder rates. Results The WOMAC pain scores were reduced by approximately 50% or more in all four groups. The 100 and 50 mg ketoprofen groups, but not the 25 mg group, showed a superior reduction in the WOMAC pain score versus the TDT 064 group (100 mg: −57.4% [P = 0.0383]; 50 mg: −57.1% [P = 0.0204]; and 25 mg: −53.4% [P = 0.3616] versus TDT 064: −49.5%). The superiority of the ketoprofen-containing formulations was not demonstrated for the WOMAC function subscale score, whereas the patient global assessment of 50 mg ketoprofen group, but not the 100 or 25 mg group, was superior to that of the TDT 064 group (P = 0.0283). Responder rates were significantly higher for all the IDEA-033 groups versus the TDT 064 group, but were high in all groups (100 mg: 88.6%; 50 mg: 86.8%; 25 mg: 88.6%; and TDT 064: 77.5%). Dermal reactions were the only relevant drug-related adverse events in all four groups. Conclusion The 50 and 100 mg ketoprofen doses of IDEA-033 were only marginally superior to TDT 064 for reducing pain associated with knee OA. The study indicates a high treatment response to the topical

  15. Intraoperative passive knee kinematics during total knee arthroplasty surgery.

    PubMed

    Young, Kathryn L; Dunbar, Michael J; Richardson, Glen; Astephen Wilson, Janie L

    2015-11-01

    Surgical navigation systems for total knee arthroplasty (TKA) surgery are capable of capturing passive three-dimensional (3D) angular joint movement patterns intraoperatively. Improved understanding of patient-specific knee kinematic changes between pre and post-implant states and their relationship with post-operative function may be important in optimizing TKA outcomes. However, a comprehensive characterization of the variability among patients has yet to be investigated. The objective of this study was to characterize the variability within frontal plane joint movement patterns intraoperatively during a passive knee flexion exercise. Three hundred and forty patients with severe knee osteoarthritis (OA) received a primary TKA using a navigation system. Passive kinematics were captured prior to (pre-implant), and after prosthesis insertion (post-implant). Principal component analysis (PCA) was used to capture characteristic patterns of knee angle kinematics among patients, to identify potential patient subgroups based on these patterns, and to examine the subgroup-specific changes in these patterns between pre- and post-implant states. The first four extracted patterns explained 99.9% of the diversity within the frontal plane angle patterns among the patients. Post-implant, the magnitude of the frontal plane angle shifted toward a neutral mechanical axis in all phenotypes, yet subtle pattern (shape of curvature) features of the pre-implant state persisted.

  16. Anterior knee pain after total knee arthroplasty: a narrative review.

    PubMed

    Petersen, Wolf; Rembitzki, Ingo Volker; Brüggemann, Gerd-Peter; Ellermann, Andree; Best, Raymond; Koppenburg, Andreas Gösele-; Liebau, Christian

    2014-02-01

    Anterior knee pain is one of the most common causes of persistent problems after implantation of a total knee replacement. It can occur in patients with or without patellar resurfacing. As a result of the surgical procedure itself many changes can occur which may affect the delicate interplay of the joint partners in the patello-femoral joint. Functional causes of anterior knee pain can be distinguished from mechanical causes. The functional causes concern disorders of inter- and intramuscular coordination, which can be attributed to preoperative osteoarthritis. Research about anterior knee pain has shown that not only the thigh muscles but also the hip and trunk stabilising muscles may be responsible for the development of a dynamic valgus malalignment. Dynamic valgus may be a causative factor for patellar maltracking. The mechanical causes of patello-femoral problems after knee replacement can be distinguished according to whether they increase instability in the joint, increase joint pressure or whether they affect the muscular lever arms. These causes include offset errors, oversizing, rotational errors of femoral or tibial component, instability, maltracking and chondrolysis, patella baja and aseptic loosening. In these cases, reoperation or revision is often necessary.

  17. Research on intraoperative iris behavior in rabbits treated with tamsulosin and finasteride

    PubMed Central

    Horvath, K; Vultur, F; Simon, V; Voidazan, S; Mühlfay, Gh

    2015-01-01

    Aim: The purpose of this study was to investigate intraoperative iris behavior during some phacoemulsification maneuvers in rabbits treated with tamsulosin or finasteride. Material and Method: An experimental study was conducted on 26 Metis male rabbits aged 1.5 - 2 years, body weight between 3.4 and 5.6 kg, divided into three groups: Group 1 - Control, 6 rabbits; Group 2 - tamsulosin, 10 rabbits; Group 3 - finasteride, 10 rabbits. Dose calculation was performed according to body surface area ratio man/rabbit, taking into account the median lethal dose LD50. Surgery study in rabbits was done over two days by the same specialist using an adapted protocol. He was not informed before or during surgeries which group the animal belonged to, the order being random with a quasi-uniform distribution. Valid results for a modified iris behavior were obtained from two steps of the procedure (cannula irrigation maneuver and irrigation-aspiration). The iris billowing was graded from 0 to 3, according to severity. Results: The risk of intraoperative iris billowing was higher in rabbits included in tamsulosin group [OR=8.33 (CI 95% 0.63-110.09)], but insignificant statistically compare with control group (p= 0.13). In rabbits treated with finasteride the risk of intraoperative iris billowing is increased compared with those without treatment [OR=11.6 (CI 95% 0.92-147.6)], but insignificant statistically (p= 0.11). Conclusion: In our research, we showed an increased risk of intraoperative iris billowing in rabbits treated with finasteride, almost similar with those obtained in rabbits treated with tamsulosin. Further experimental or clinical studies to confirm the role of finasteride in the etiology of intraoperative floppy iris syndrome in humans are needed. Hippokratia 2015, 19 (1): 20-24. PMID:26435641

  18. Pre-radiographic MRI findings are associated with onset of knee symptoms: the most study

    PubMed Central

    Javaid, M. K.; Lynch, J. A.; Tolstykh, I.; Guermazi, A.; Roemer, F.; Aliabadi, P.; McCulloch, C.; Curtis, J.; Felson, D.; Lane, N. E.; Torner, J.; Nevitt, M.

    2010-01-01

    Summary Objective Magnetic resonance imaging (MRI) has greater sensitivity to detect osteoarthritis (OA) damage than radiographs but it is uncertain which MRI findings in early OA are clinically important. We examined MRI abnormalities detected in knees without radiographic OA and their association with incident knee symptoms. Method Participants from the Multicenter Osteoarthritis Study (MOST) without frequent knee symptoms (FKS) at baseline were eligible if they also lacked radiographic features of OA at baseline. At 15 months, knees that developed FKS were defined as cases while control knees were drawn from those that remained without FKS. Baseline MRIs were scored at each subregion for cartilage lesions (CARTs); osteophytes (OST); bone marrow lesions (BML) and cysts. We compared cases and controls using marginal logistic regression models, adjusting for age, gender, race, body mass index (BMI), previous injury and clinic site. Results 36 case knees and 128 control knees were analyzed. MRI damage was common in both cases and controls. The presence of a severe CART (P = 0.03), BML (P = 0.02) or OST (P = 0.02) in the whole knee joint was more common in cases while subchondral cysts did not differ significantly between cases and controls (P > 0.1). Case status at 15 months was predicted by baseline damage at only two locations; a BML in the lateral patella (P = 0.047) and at the tibial subspinous subregions (P = 0.01). Conclusion In knees without significant symptoms or radiographic features of OA, MRI lesions of OA in only a few specific locations preceded onset of clinical symptoms and suggest that changes in bone play a role in the early development of knee pain. Confirmation of these findings in other prospective studies of knee OA is warranted. PMID:19919856

  19. Neuromuscular alterations during walking in persons with moderate knee osteoarthritis.

    PubMed

    Hubley-Kozey, C L; Deluzio, K J; Landry, S C; McNutt, J S; Stanish, W D

    2006-08-01

    This paper compared the neuromuscular responses during walking between those with early-stage knee osteoarthritis (OA) to asymptomatic controls. The rationale for studying those with mild to moderate knee OA was to determine the alterations in response to dynamic loading that might be expected before severe pain, joint space narrowing and joint surface changes occur. We used pattern recognition techniques to explore both amplitude and shape changes of the surface electromyograms recorded from seven muscles crossing the knee joint of 40 subjects with knee OA and 38 asymptomatic controls during a walking task. The principal patterns for each muscle grouping explained over 83% of the variance in the waveforms. This result supported the notion that the main neuromuscular patterns were similar between asymptomatic controls and those with OA, reflecting the specific roles of the major muscles during walking. ANOVA revealed significant (p<0.05) differences in the principal pattern scores reflecting both amplitude and shape alterations in the OA group and among muscles. These differences captured subtle changes in the neuromuscular responses of the subjects with OA throughout different phases of the gait cycle and most likely reflected changes in the mechanical environment (joint loading, instability) and pain. The subjects with OA attempted to increase activity of the lateral sites and reduce activity in the medial sites, having minimal but prolonged activity during late stance. Therefore, alterations in neuromuscular responses were found even in this high functioning group with moderate knee OA.

  20. Knee joint forces during downhill walking with hiking poles.

    PubMed

    Schwameder, H; Roithner, R; Müller, E; Niessen, W; Raschner, C

    1999-12-01

    The aim of this study was to determine external and internal loads on the knee joint during downhill walking with and without hiking poles. Kinematic, kinetic and electromyographic data were collected from eight males during downhill walking on a ramp declined at 25 degrees. Planar knee joint moments and forces were calculated using a quasi-static knee model. The results were analysed for an entire pole-cycle as well as differentiated between single and double support phases and between each step of a pole-cycle. Significant differences between downhill walking with and without hiking poles were observed for peak and average magnitudes of ground reaction force, knee joint moment, and tibiofemoral compressive and shear forces (12-25%). Similar reductions were found in patellofemoral compressive force, the quadriceps tendon force and the activity of the vastus lateralis; however, because of a high variability, these differences were not significant. The reductions seen during downhill walking with hiking poles compared with unsupported downhill walking were caused primarily by the forces applied to the hiking poles and by a change in posture to a more forward leaning position of the upper body, with the effect of reducing the knee moment arm.

  1. Unique Anatomic Feature of the Posterior Cruciate Ligament in Knees Associated With Osteochondritis Dissecans

    PubMed Central

    Ishikawa, Masakazu; Adachi, Nobuo; Yoshikawa, Masahiro; Nakamae, Atsuo; Nakasa, Tomoyuki; Ikuta, Yasunari; Hayashi, Seiju; Deie, Masataka; Ochi, Mitsuo

    2016-01-01

    Background: Osteochondritis dissecans (OCD) of the knee is a disorder in juveniles and young adults; however, its etiology still remains unclear. For OCD at the medial femoral condyle (MFC), it is sometimes observed that the lesion has a connection with fibers of the posterior cruciate ligament (PCL). Although this could be important information related to the etiology of MFC OCD, there is no report examining an association between the MFC OCD and the PCL anatomy. Purpose: To investigate the anatomic features of knees associated with MFC OCD, focusing especially on the femoral attachment of the PCL, and to compare them with knees associated with lateral femoral condyle (LFC) OCD and non-OCD lesions. Study Design: Case-control study; Level of evidence, 3. Methods: We retrospectively reviewed 39 patients (46 knees) with OCD lesions who had undergone surgical treatment. Using magnetic resonance imaging (MRI) scans, the PCL attachment at the lateral wall of the MFC was measured on the coronal sections, and the knee flexion angle was also measured on the sagittal sections. As with non-OCD knees, we reviewed and analyzed 25 knees with anterior cruciate ligament (ACL) injuries and 16 knees with meniscal injuries. Results: MRIs revealed that the femoral PCL footprint was located in a significantly more distal position in the patients with MFC OCD compared with patients with LFC OCD and ACL and meniscal injuries. There was no significant difference in knee flexion angle among the 4 groups. Conclusion: The PCL in patients with MFC OCD attached more distally at the lateral aspect of the MFC compared with knees with LFC OCD and ACL and meniscal injuries. PMID:27294170

  2. Predicting Knee Osteoarthritis.

    PubMed

    Gardiner, Bruce S; Woodhouse, Francis G; Besier, Thor F; Grodzinsky, Alan J; Lloyd, David G; Zhang, Lihai; Smith, David W

    2016-01-01

    Treatment options for osteoarthritis (OA) beyond pain relief or total knee replacement are very limited. Because of this, attention has shifted to identifying which factors increase the risk of OA in vulnerable populations in order to be able to give recommendations to delay disease onset or to slow disease progression. The gold standard is then to use principles of risk management, first to provide subject-specific estimates of risk and then to find ways of reducing that risk. Population studies of OA risk based on statistical associations do not provide such individually tailored information. Here we argue that mechanistic models of cartilage tissue maintenance and damage coupled to statistical models incorporating model uncertainty, united within the framework of structural reliability analysis, provide an avenue for bridging the disciplines of epidemiology, cell biology, genetics and biomechanics. Such models promise subject-specific OA risk assessment and personalized strategies for mitigating or even avoiding OA. We illustrate the proposed approach with a simple model of cartilage extracellular matrix synthesis and loss regulated by daily physical activity.

  3. Knee Replacement: MedlinePlus Health Topic

    MedlinePlus

    ... Arthritis and Musculoskeletal and Skin Diseases) Also in Spanish Knee Replacement (Mayo Foundation for Medical Education and ... American Academy of Orthopaedic Surgeons) - PDF Also in Spanish Total Knee Replacement (Arthroplasty) (Beyond the Basics) (UpToDate) ...

  4. [What's new about total knee arthroplasty].

    PubMed

    Dao Trong, Mai Lang; Helmy, Näder

    2013-10-30

    Osteoarthritis of the knee is one of the most common problems in the orthopedic practice and its surgical technique is still challenging. This Mini-Review presents patient specific cutting blocks for the implantation of a total knee arthroplasty.

  5. Knee joint forces: prediction, measurement, and significance

    PubMed Central

    D’Lima, Darryl D.; Fregly, Benjamin J.; Patil, Shantanu; Steklov, Nikolai; Colwell, Clifford W.

    2011-01-01

    Knee forces are highly significant in osteoarthritis and in the survival and function of knee arthroplasty. A large number of studies have attempted to estimate forces around the knee during various activities. Several approaches have been used to relate knee kinematics and external forces to internal joint contact forces, the most popular being inverse dynamics, forward dynamics, and static body analyses. Knee forces have also been measured in vivo after knee arthroplasty, which serves as valuable validation of computational predictions. This review summarizes the results of published studies that measured knee forces for various activities. The efficacy of various methods to alter knee force distribution, such as gait modification, orthotics, walking aids, and custom treadmills are analyzed. Current gaps in our knowledge are identified and directions for future research in this area are outlined. PMID:22468461

  6. [Studies of the neuromuscular system of the knee joint].

    PubMed

    Börnert, K; Dippold, A

    1990-02-01

    The paper analysis the therapeutic effects of isometric training and electromechanic therapy (EMT) of the quadriceps muscles on subjects. The effects of the training practised with the knee joint bent was to be compared with previous results of training with the knee joint stretched. 36 subjects were trained and the increase in strength was measured with the help of a strain gauge dynamometer. Again a marked superiority of the EMT over sole isometric training could be demonstrated. More over, the results showed that the increase of the isometric maximal strength following an EMT is not influenced by the position of the angle of the joint.

  7. Research On The Special Moving Pair. The Moire Contour Fringes On The Femoral Articular Facies Of Knee Of Pongidae

    NASA Astrophysics Data System (ADS)

    Qu, Wenzi; Lan, Zuyun; Zhang, Renxiang

    1987-02-01

    Articulation is the special moving pair in the body of animal. In this article, the different forms and the comparative targets of the moire contour fringes on two condyles of knee of Pongidae, and comparative study of the articulation of knee between the Gorilla, Orangutan and Chimpanzee are given.

  8. Effects of intraarticular 32P colloid in the treatment of hemophilic synovitis of the knee: A short term clinical study

    PubMed Central

    Zhang, Wen-Qiang; Han, Shao-Qin; Yuan, Zhen; He, Ye-Teng; Zhang, Hu; Zhang, Ming

    2016-01-01

    Background: Chronic synovitis is a consequence of recurrent intraarticular hemorrhage in patients with hemophilia. Eventually, synovitis leads to degeneration of the articular cartilage, with serious consequences that impact the quality-of-life in hemophiliacs. The aim of our study was to investigate the short term clinical effects of intraarticular injection of the radionuclide preparation32P colloid (32P-labelled colloidal chromic phosphate suspension) on recurrent intraarticular hemorrhages in patients with hemophilic synovitis of the knee. Materials and Methods: Patients who met the inclusion criteria (n = 22) were enrolled in an open-label study between October 2011 and September 2012.32P colloid was injected into the knee joint and patients were followed up over 6 months after treatment. Hemorrhage frequency, visual analog scale pain score, hospital for special surgery knee score, knee circumference, upper knee circumference, knee diameter, and knee range of motion (ROM) were compared before and after treatment with intraarticular32P colloid injection. Results: In 24 knees evaluated in 22 participating patients, there was a significant reduction in the number of hemorrhages after32P colloid treatment, along with significant pain relief. However, there were no statistically significant changes in the degree of joint swelling, degree of muscle atrophy and knee ROM between the pre and post treatment evaluations. Conclusion: The frequency of joint hemorrhage in patients with hemophilic knee synovitis can be significantly reduced and local symptoms can be improved in the short term by intraarticular injection of32P colloid. PMID:26955177

  9. Vitamin E protects against impairment of endothelium-mediated relaxations in cholesterol-fed rabbits.

    PubMed

    Stewart-Lee, A L; Forster, L A; Nourooz-Zadeh, J; Ferns, G A; Anggård, E E

    1994-03-01

    The vascular effects of dietary vitamin E were investigated in isolated carotid artery preparations from cholesterol-fed New Zealand White rabbits. Rabbits were fed either a control, 1% cholesterol, or 1% cholesterol plus 0.2% vitamin E diet for 4 weeks. In raised-tone preparations, relaxant responses to acetylcholine were enhanced in rabbits fed cholesterol plus vitamin E, reversing the reduction in responses measured in preparations from cholesterol-fed rabbits. Relaxant responses to the calcium ionophore A23187 were significantly enhanced in cholesterol plus vitamin E-fed rabbits compared with those fed cholesterol alone, with no difference between control and cholesterol-fed rabbits. Relaxant responses to sodium nitroprusside were not different between the three dietary groups. Constrictor responses to noradrenaline and serotonin in isolated carotid artery preparations at basal tone were unaltered after cholesterol and cholesterol plus vitamin E diets. The copper-induced oxidation of beta-very-low-density lipoproteins (beta VLDL) isolated from plasma of rabbits fed a cholesterol plus vitamin E diet was almost completely inhibited compared with the oxidation of beta VLDL from rabbits fed cholesterol alone. These results show that vitamin E prevents endothelial dysfunction associated with cholesterol feeding and suggests that vitamin E may be beneficial in preventing functional impairment associated with atherosclerosis.

  10. Comparison between closed suction drainage and nondrainage in total knee arthroplasty: a meta-analysis.

    PubMed

    Zhang, Qi-dong; Guo, Wan-shou; Zhang, Qian; Liu, Zhao-hui; Cheng, Li-ming; Li, Zi-rong

    2011-12-01

    From individual randomized studies, it is not clear whether a closed suction drainage should be used after total knee arthroplasty. Our meta-analysis compares the clinical outcomes of closed suction drainage with nondrainage after total knee arthroplasty in randomized controlled trials reported between January 1966 and May 2010. Fifteen eligible trials involving 1361 knee incisions (686 knees with closed suction drainage and 675 knees without drainage) satisfied the inclusion criteria for our meta-analysis. The result of the meta-analysis indicates that closed suction drainage reduces the incidence of soft tissue ecchymosis and requirement for dressing reinforcement, but increases the rate of homologous blood transfusion. No significant difference between drainage and nondrainage was observed in the incidence of infection, deep venous thrombosis, or postoperative range of motion.

  11. Effect of Planning on Trunk Motion and Knee Moments During a Side Step Cut Task

    NASA Astrophysics Data System (ADS)

    Houck, Jeff; Gorniak, Stacey; Nicholson, Kristen

    2004-03-01

    Recent studies suggest that alterations in knee biomechanics associated with unanticipated cutting tasks place athletes at higher risk of knee injuries. Besier et al observed alterations in knee moments during unanticipated cutting tasks that were consistent with in-vitro ACL injury mechanisms. During similar tasks, Patla et al observed lateral trunk lean and decreased foot placement, suggesting that full body center of mass control is perturbed during such tasks. The purpose of this study was to compare the trunk and knee frontal plane moments and evaluate a relationship between the two during unanticipated cutting tasks. The results of this study suggest that there is a relationship between the trunk and knee frontal plane moments during the first 200-400ms of the stance phase of gait.

  12. Regaining Native Knee Kinematics Following Joint Arthroplasty: A Novel Biomimetic Design with ACL and PCL Preservation.

    PubMed

    Zumbrunn, Thomas; Varadarajan, Kartik Mangudi; Rubash, Harry E; Malchau, Henrik; Li, Guoan; Muratoglu, Orhun K

    2015-12-01

    Lack of ACL and non-anatomic articular surfaces in contemporary total knee implants result in kinematic abnormalities. We hypothesized that such abnormalities may be addressed with a biomimetic bi-cruciate retaining (BCR) design having anatomical articular surfaces. We used dynamic computer simulations to compare kinematics among the biomimetic BCR, a contemporary BCR and cruciate-retaining implant for activities of daily living. During simulated deep knee bend, chair-sit and walking, the biomimetic BCR implant showed activity dependent kinematics similar to healthy knees in vivo. Restoring native knee geometry together with ACL preservation provided these kinematic improvements over contemporary ACL-preserving and ACL-sacrificing implants. Further clinical studies are required to determine if such biomimetic implants can result in more normal feeling knees and improve quality of life for active patients.

  13. Metabolism of perhydroanthracenes in the rabbit

    PubMed Central

    Robertson, J. S.; Dunstan, P. J.

    1971-01-01

    1. The metabolism in rabbits of several perhydroanthracenes was investigated. All compounds were to different degrees excreted in the urine as glucuronides. 2. The aglycones of the glucuronides were found to be racemic secondary alcohols, having the hydroxyl group at a β-methylene carbon. Where determinable, the hydroxyl group was shown to have an equatorial configuration. 3. These results suggested that hydroxylation was enzyme mediated, and, when compared with the results from studies on other alicyclic hydrocarbons, that the same enzyme system participated generally in the hydroxylation of such hydrocarbons. 4. A model for the enzyme active site is proposed to accord with the pattern of hydroxylation observed. PMID:5135241

  14. Knee Control and Jump-Landing Technique in Young Basketball and Floorball Players.

    PubMed

    Leppänen, M; Pasanen, K; Kulmala, J-P; Kujala, U M; Krosshaug, T; Kannus, P; Perttunen, J; Vasankari, T; Parkkari, J

    2016-04-01

    Poor knee alignment is associated with increased loading of the joints, ligaments and tendons, and may increase the risk of injury. The study purpose was to compare differences in knee kinematics between basketball and floorball players during a vertical drop jump (VDJ) task. We wanted to investigate whether basketball players, whose sport includes frequent jump-landings, exhibited better knee control compared with floorball players, whose sport involves less jumping. Complete data was obtained from 173 basketball and 141 floorball players. Peak knee valgus and flexion angles during the VDJ were analyzed by 3D motion analysis.Larger knee valgus angles were observed among basketball players (- 3.2°, 95%CI -4.5 to - 2.0) compared with floorball players (- 0.9°, 95%CI -2.3 to 0.6) (P=0.022). Basketball players landed with a decreased peak knee flexion angle (83.1°, 95%CI 81.4 to 84.8) compared with floorball players (86.5°, 95%CI 84.6 to 88.4) (P=0.016). There were no significant differences in height, weight or BMI between basketball and floorball players. Female athletes exhibited significantly greater valgus angles than males. This study revealed that proper knee control during jump-landing does not seem to develop in young athletes simply by playing the sport, despite the fact that jump-landings occur frequently in practice and games.

  15. The Change in Knee Angle during the Gait by Applying Elastic Tape to the Skin.

    PubMed

    Yamamoto, Hiroyuki

    2014-07-01

    [Purpose] The aim of this study was to verify how the application of elastic tape to the anterior surface of the thigh changes the knee angle pattern during gait. [Subjects] The subjects were 10 people who showed an abnormal knee angle change pattern during usual walking. They did not show the so-called double knee action. [Methods] Subjects were asked to walk as usual, and then to walk with elastic tape attached to the anterior surface of the thigh. The knee angle was measured during gait with an electronic goniometer. We graphed the temporal changes of the knee angle and compared them with the normal gait pattern. [Results] The knee angle gait pattern of six of the 10 subjects improved after application of the tape and became like a normal gait pattern. The changes in the knee angle resulted from a stimulus via the skin, rather than voluntary muscular adjustment, suggesting that the changes may have originated due to differences in reflexive tensile strength. [Conclusion] In normal speed gait, it is suggested that the knee angle was altered such that it exhibited a normal pattern by applying elastic tape to the anterior surface of the thigh. We suspect that application of the elastic tape may change the muscle tonus.

  16. The Change in Knee Angle during the Gait by Applying Elastic Tape to the Skin

    PubMed Central

    Yamamoto, Hiroyuki

    2014-01-01

    [Purpose] The aim of this study was to verify how the application of elastic tape to the anterior surface of the thigh changes the knee angle pattern during gait. [Subjects] The subjects were 10 people who showed an abnormal knee angle change pattern during usual walking. They did not show the so-called double knee action. [Methods] Subjects were asked to walk as usual, and then to walk with elastic tape attached to the anterior surface of the thigh. The knee angle was measured during gait with an electronic goniometer. We graphed the temporal changes of the knee angle and compared them with the normal gait pattern. [Results] The knee angle gait pattern of six of the 10 subjects improved after application of the tape and became like a normal gait pattern. The changes in the knee angle resulted from a stimulus via the skin, rather than voluntary muscular adjustment, suggesting that the changes may have originated due to differences in reflexive tensile strength. [Conclusion] In normal speed gait, it is suggested that the knee angle was altered such that it exhibited a normal pattern by applying elastic tape to the anterior surface of the thigh. We suspect that application of the elastic tape may change the muscle tonus. PMID:25140100

  17. The effect of sustained static kneeling on kinetic and kinematic knee joint gait parameters.

    PubMed

    Kajaks, Tara; Costigan, Patrick

    2015-01-01

    Despite epidemiological evidence for kneeling as an occupational risk factor for knee osteoarthritis, biomechanical evidence is lacking. Gait knee joint mechanics, a common measure used to study knee osteoarthritis initiation, were used in the present study to investigate the effect of sustained static kneeling on the knee. Ten healthy male subjects (24.1 years ± 3.5) performed ten baseline walking trials, followed by a 30-min kneeling protocol and a second set of walking trials. Knee joint moments and angles were calculated during the stance phase. Within-subject root mean squared differences were compared within and between the pre- and post-kneeling gait trials. Differences were observed between the pre-kneeling and post-kneeling walking trails for flexion and adduction knee moments (0.12 Nm/kg ± 0.03, 0.07 Nm/kg ± 0.02) and angles (3.18° ± 1.22 and 1.64° ± 1.15), indicating that sustained static deep-knee flexion kneeling does acutely alter knee joint gait parameters.

  18. Use of knee height for the estimation of body height in Thai adult women.

    PubMed

    Chumpathat, Nopphanath; Rangsin, Ram; Changbumrung, Supranee; Soonthornworasiri, Ngamphol; Durongritichai, Vanida; Kwanbunjan, Karunee

    2016-01-01

    Knee height has been the most frequently used measure for height prediction where full height is difficult to measure. The aim of this study was to develop and validate predictive equations using knee height to estimate the height of Thai women. The female participants were 18-59 years of age and lived in Bangkok or three surrounding provinces. They were assigned to one of two groups; the equation development group (n=488) and the equation validation group (n=188). Standing height and knee height were measured in duplicate using a stadiometer and a knee height calliper. Age and physical characteristics of the equation development group and the validate group were comparable. The measured heights showed a significant strongly positive correlation with the mean knee height (r=0.84, p<0.001). Mean knee height in a regression model exhibited the most accurate height prediction (adjusted R(2)=0.718, standard error of estimate=2.80), according to the equation "Height=38.1+2.45 (average knee height) - 0.051(age)". This study proposes a new height estimation equation for Thai adult women using knee height. The equation shows more estimation power than the previous studies conducted in Thailand.

  19. Design and Evaluation of a Prosthetic Knee Joint Using the Geared Five-Bar Mechanism.

    PubMed

    Sun, Yuanxi; Ge, Wenjie; Zheng, Jia; Dong, Dianbiao

    2015-11-01

    This paper presents the mechanical design, dynamics analysis and ankle trajectory analysis of a prosthetic knee joint using the geared five-bar mechanism. Compared with traditional four-bar or six-bar mechanisms, the geared five-bar mechanism is better at performing diverse movements and is easy to control. This prosthetic knee joint with the geared five-bar mechanism is capable of fine-tuning its relative instantaneous center of rotation and ankle trajectory. The centrode of this prosthetic knee joint, which is mechanically optimized according to the centrode of human knee joint, is better in the bionic performance than that of a prosthetic knee joint using the four-bar mechanism. Additionally, the stability control of this prosthetic knee joint during the swing and stance phase is achieved by a motor. By adjusting the gear ratio of this prosthetic knee joint, the ankle trajectories of both unilateral and bilateral amputees show less deviations from expected than that of the four-bar knee joint.

  20. The effect of ankle bracing on knee kinetics and kinematics during volleyball-specific tasks.

    PubMed

    West, T; Ng, L; Campbell, A

    2014-12-01

    The purpose of this study was to examine the effects of ankle bracing on knee kinetics and kinematics during volleyball tasks. Fifteen healthy, elite, female volleyball players performed a series of straight-line and lateral volleyball tasks with no brace and when wearing an ankle brace. A 14-camera Vicon motion analysis system and AMTI force plate were used to capture the kinetic and kinematic data. Knee range of motion, peak knee anterior-posterior and medial-lateral shear forces, and peak ground reaction forces that occurred between initial contact with the force plate and toe off were compared using paired sample t-tests between the braced and non-braced conditions (P < 0.05). The results revealed no significant effect of bracing on knee kinematics or ground reaction forces during any task or on knee kinetics during the straight-line movement volleyball tasks. However, ankle bracing was demonstrated to reduce knee lateral shear forces during all of the lateral movement volleyball tasks. Wearing the Active Ankle T2 brace will not impact knee joint range of motion and may in fact reduce shear loading to the knee joint in volleyball players.

  1. Chronic Changes in the Articular Cartilage and Meniscus Following Traumatic Impact to the Lapine Knee

    PubMed Central

    Fischenich, Kristine M.; Button, Keith D.; Coatney, Garrett A.; Fajardo, Ryan S.; Leikert, Kevin M.; Haut, Roger C.; Haut Donahue, Tammy L.

    2014-01-01

    The objective of this study was to induce anterior cruciate ligament (ACL) and meniscal damage, via a single tibiofemoral compressive impact, in order to document articular cartilage and meniscal changes post impact. Tibiofemoral joints of Flemish Giant rabbits were subjected to a single blunt impact that ruptured the ACL and produced acute meniscal damage. Animals were allowed unrestricted cage activity for 12 weeks before euthanasia. India ink analysis of the articular cartilage revealed higher degrees of surface damage on the impacted tibias (p=0.018) and femurs (p<0.0001) compared to controls. Chronic meniscal damage was most prevalent in the medial central and medial posterior regions. Mechanical tests revealed an overall 19.4% increase in tibial plateau cartilage thickness (p=0.026), 34.8% increase in tibial plateau permeability (p=0.054), 40.8% increase in femoral condyle permeability (p=0.029), and 20.1% decrease in femoral condyle matrix modulus (p=0.012) in impacted joints compared to controls. Both the instantaneous and equilibrium moduli of the lateral and medial menisci were decreased compared to control (p<0.02). Histological analyses revealed significantly increased presence of fissures in the medial femur (p = 0.036). In both the meniscus and cartilage there was a significant decrease in GAG coverage for the impacted limbs. Based on these results it is clear that an unattended combined meniscal and ACL injury results in significant changes to the soft tissues in this experimental joint 12 weeks post injury. Such changes are consistent with a clinical description of mid to late stage PTOA of the knee. PMID:25523754

  2. Neurological Assessment Scores in Rabbit Embolic Stroke Models

    PubMed Central

    Brown, Aliza; Woods, Sean; Skinner, Robert; Hatton, Jeff; Lowery, John; Roberson, Paula; Hennings, Leah; Culp, William C

    2013-01-01

    Background: Neurological outcomes and behavioral assessments are widely used in animal models of stroke, but assessments in rabbit models are not fully validated. The wryneck model of neurological assessment scores (NAS) was compared to percent infarct volume (%IV) values (infarct volume is a proven clinical indicator of stroke severity) and arterial occlusion localization in three rabbit angiographic stroke models. Hypothesis: NAS values will correlate with percent infarct volume values. Methods: Anesthetized New Zealand White rabbits (N=131, 4-5 kg) received internal carotid artery emboli by angiographic catheter introduced into the femoral artery and occlusions were characterized. Rabbits were evaluated at 24 hours post embolism using the NAS test of 0 (normal) to 10 (death). Deficit criteria included neck twist, righting reflex, extension reflex in hind paw and forepaw, and posture. Brain sections stained with triphenyltetrazolium chloride (TTC) were analyzed for %IV. Volume of the infarct was measured and calculated as a percent of the total brain volume. Results: The aggregate correlation for NAS values vs. %IV values was R=0.61, p<0.0001, a strong positive relationship, while correlations of the NAS components ranged from R=0.28-0.46. Occlusionsof the posterior cerebral artery vs. the middle cerebral artery alone produced significantly greater deficit scores at p<0.0001. Conclusions: These positive results validate the NAS system in the rabbit angiographic embolic stroke model. PMID:24265650

  3. Vaccine breaks: Outbreaks of myxomatosis on Spanish commercial rabbit farms.

    PubMed

    Dalton, K P; Nicieza, I; de Llano, D; Gullón, J; Inza, M; Petralanda, M; Arroita, Z; Parra, F

    2015-08-05

    Despite the success of vaccination against myxoma virus, myxomatosis remains a problem on rabbit farms throughout Spain and Europe. In this study we set out to evaluate possible causes of myxoma virus (MYXV) vaccine failures addressing key issues with regard to pathogen, vaccine and vaccination strategies. This was done by genetically characterising MYXV field isolates from farm outbreaks, selecting a representative strain for which to assay its virulence and measuring the protective capability of a commercial vaccine against this strain. Finally, we compare methods (route) of vaccine administration under farm conditions and evaluate immune response in vaccinated rabbits. The data presented here show that the vaccine tested is capable of eliciting protection in rabbits that show high levels of seroconversion. However, the number of animals failing to seroconvert following subcutaneous vaccination may leave a large number of rabbits unprotected following vaccine administration. Successful vaccination requires the strict implication of workable, planned, on farm programs. Following this, analysis to confirm seroconversion rates may be advisable. Factors such as the wild rabbit reservoir, control of biting insects and good hygienic practices must be taken into consideration to prevent vaccine failures from occurring.

  4. Moxibustion Treatment for Knee Osteoarthritis

    PubMed Central

    Li, Ang; Wei, Zhi-Jian; Liu, Yi; Li, Bo; Guo, Xing; Feng, Shi-Qing

    2016-01-01

    Abstract To determine whether the administration of moxibustion is an effective treatment for knee osteoarthritis (KOA). We conducted a search of relevant articles using Medline, EMBASE, the Web of Science, and the Cochrane Library published before October 2015. The Western Ontario and McMaster Universities’ Osteoarthritis Index (WOMAC scale) and the short form 36 questionnaire (SF-36 scale) were assessed. Evidence grading was evaluated according to the Grading of Recommendations, Assessment, Development and Evaluation system. Four studies containing 746 participants fulfilled the inclusion criteria in the final analysis. In terms of quality of life (QOL), the meta-analysis of 2 randomized clinical trials (RCTs) showed significantly effects of moxibustion only in bodily pain (BP) compared with those in the control group (n = 348; weighted mean difference [WMD], 4.36; 95% confidence intervals [CIs], 2.27–6.44; P < 0.0001; heterogeneity: χ2 = 1.53, P = 0.22, I2 = 34%) in all of the subcategories of the SF-36 scale, with moderate quality. The meta-analysis of the 2 included trials showed that there was not a statistically significant difference in the pain or function subscale for the WOMAC scale when the 2 groups were compared (n = 322; WMD, 17.63; 95% CI, −23.15–58.41; P = 0.40; heterogeneity: χ2 = 19.42, P < 0.0001, I2 = 95%), with low or moderate quality separately. The administration of moxibustion can to some extent alleviate the symptoms of KOA. More rigorous, randomized controlled trials are required in the future. PMID:27057863

  5. Automatically Locking/Unlocking Orthotic Knee Joint

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce

    1994-01-01

    Proposed orthotic knee joint locks and unlocks automatically, at any position within range of bend angles, without manual intervention by wearer. Includes tang and clevis, locks whenever wearer transfers weight to knee and unlocks when weight removed. Locking occurs at any angle between 45 degrees knee bend and full extension.

  6. Knee Replacement - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Knee Replacement (Arabic) العربية Bilingual PDF Health Information Translations Bosnian (Bosanski) Total Knee Replacement Potpuna zamjena koljena - Bosanski (Bosnian) Bilingual PDF Health Information Translations Chinese - Simplified (简体中文) Total Knee Replacement 全膝关节置换 - 简体中文 ( ...

  7. [Deep Relief sonophoresis in degenerative changes of the knee joint].

    PubMed

    Zjuzin, Nada; Muftić, Mirsad; Avdić, Dijana; Zubcević, Haris; Stefanovski, Mihajlo; Stefanovski, Gordana; Lukać, Tamara; Hotić, Asia; Halilbegović, Emir; Kapidzić, Nedima

    2004-01-01

    We analysed 130 persons with osteoarthritis of knee and compared efficiency Deep Relief gel with sonophoresis and ultrasound with standard gel. Deep Relief has significant better effect for less pain and better improvement of functional capacity in comparison with ultrasound. Results of examination are statistic significant.

  8. Knee Osteoarthritis: Does Transcutaneous Electrical Nerve Stimulation Work?

    PubMed

    Cherian, Jeffrey J; Kapadia, Bhaveen H; McElroy, Mark J; Johnson, Aaron J; Bhave, Anil; Harwin, Steven F; Mont, Michael A

    2016-01-01

    Transcutaneous electrical nerve stimulation has been proposed as a nonoperative treatment for osteoarthritis. The purpose of this study was to evaluate the outcomes of a novel transcutaneous electrical nerve stimulation device compared with those of other standard nonoperative modalities for the treatment of osteoarthritis of the knee.

  9. Use of host population reduction to control wildlife infection: rabbits and paratuberculosis.

    PubMed

    Davidson, R S; Marion, G; White, P C L; Hutchings, M R

    2009-01-01

    Reduction in wildlife populations is a common method for the control of livestock infections which have wildlife hosts, but its success is dependent on the characteristics of the infection itself, as well as on the spatial and social structure of the wildlife host. Paratuberculosis (Mycobacterium avium subsp. paratuberculosis; Map) is a widespread and difficult infection to control in livestock populations and also has possible links to Crohn's disease in humans. Rabbits have recently been identified as a key wildlife species in terms of paratuberculosis persistence in the environment and risk to the wider host community, including cattle. Here we use a spatially explicit stochastic simulation model of Map dynamics in rabbit populations to quantify the effects of rabbit population control on infection persistence. The model parameters were estimated from empirical studies of rabbit population dynamics and rabbit-to-rabbit routes of Map transmission. Three rabbit control strategies were compared: single unrepeated population reductions based on removing individual animals; single unrepeated population reductions based on removal of entire social groups; and repeated annual population reductions based on removing individual animals. Unrealistically high rabbit culls (>95% population reduction) are needed if infection is to be eradicated from local rabbit populations with a single one-off population reduction event, either of individuals or social groups. Repeated annual culls are more effective at reducing the prevalence of infection in rabbit populations and eradicating infection. However, annual population reductions of >40% are required over extended periods of time (many years). Thus, using an approach which is both highly conservative and parsimonious with respect to estimating lower bounds on the time to eradicate the infection, we find that Map is extremely persistent in rabbit populations and requires significant and prolonged effort to achieve control.

  10. Molecular characterization and expression analysis of fat mass and obesity-associated gene in rabbit.

    PubMed

    Xing, Jinyi; Jing, Wenqian; Jiang, Yunliang

    2013-12-01

    Fat mass and obesity-associated (FTO) gene codes for a nuclear protein of the AlkB related nonhaem iron and 2-oxoglutaratedependent oxygenase superfamily, and is involved in animal fat deposition and human obesity. In this work, the molecular characterization and expression features of rabbit (Oryctolagus cuniculus) FTO cDNA were analysed. The rabbit FTO cDNA with a size of 2158 bp was cloned, including 1515 bp of the open reading frame that encoded a basic protein of 504 amino acids. Homologous comparison indicated that the rabbit FTO shared 36.36-91.88% identity with those from other species and phylogenetic analysis showed that the rabbit FTO is closely related to human, but more distantly related to zebrafish. The New Zealand rabbit FTO mRNA was detected in all tissues examined, with the highest levels found in the spleen and the lowest found in the kidney. However, no significant differences were seen in cerebellum, corpora quadrigemina, medulla oblongata and cerebral cortex of commercial adult rabbits. Moreover, mRNA levels of FTO in liver tissues were significantly increased in lactating New Zealand rabbits compared with 70-day-old, 90-day-old and gestating rabbits (P < 0.05). In contrast, FTO mRNA levels were significantly lower in longissimus dorsi muscle of 90-day-old New Zealand rabbits than in 70-day-old rabbits (P <0.05). However, the expression levels of FTO in mammary gland and ovary of gestating and lactating rabbits were not significantly different (P > 0.05).

  11. Unexpected inhibition of cholesterol 7 alpha-hydroxylase by cholesterol in New Zealand white and Watanabe heritable hyperlipidemic rabbits.

    PubMed Central

    Xu, G; Salen, G; Shefer, S; Ness, G C; Nguyen, L B; Parker, T S; Chen, T S; Zhao, Z; Donnelly, T M; Tint, G S

    1995-01-01

    We investigated the effect of cholesterol feeding on plasma cholesterol concentrations, hepatic activities and mRNA levels of HMG-CoA reductase and cholesterol 7 alpha-hydroxylase and hepatic LDL receptor function and mRNA levels in 23 New Zealand White (NZW) and 17 Watanabe heritable hyperlipidemic (WHHL) rabbits. Plasma cholesterol concentrations were 9.9 times greater in WHHL than NZW rabbits and rose significantly in both groups when cholesterol was fed. Baseline liver cholesterol levels were 50% higher but rose only 26% in WHHL as compared with 3.6-fold increase with the cholesterol diet in NZW rabbits. In both rabbit groups, hepatic total HMG-CoA reductase activity was similar and declined > 60% without changing enzyme mRNA levels after cholesterol was fed. In NZW rabbits, cholesterol feeding inhibited LDL receptor function but not mRNA levels. As expected, receptor-mediated LDL binding was reduced in WHHL rabbits. Hepatic cholesterol 7 alpha-hydroxylase activity and mRNA levels were 2.8 and 10.4 times greater in NZW than WHHL rabbits. Unexpectedly, cholesterol 7 alpha-hydroxylase activity was reduced 53% and mRNA levels were reduced 79% in NZW rabbits with 2% cholesterol feeding. These results demonstrate that WHHL as compared with NZW rabbits have markedly elevated plasma and higher liver cholesterol concentrations, less hepatic LDL receptor function, and very low hepatic cholesterol 7 alpha-hydroxylase activity and mRNA levels. Feeding cholesterol to NZW rabbits increased plasma and hepatic concentrations greatly, inhibited LDL receptor-mediated binding, and unexpectedly suppressed cholesterol 7 alpha-hydroxylase activity and mRNA to minimum levels similar to WHHL rabbits. Dietary cholesterol accumulates in the plasma of NZW rabbits, and WHHL rabbits are hypercholesterolemic because reduced LDL receptor function is combined with decreased catabolism of cholesterol to bile acids. Images PMID:7706454

  12. The Transseptal Arthroscopic Knee Portal Is in Close Proximity to the Popliteal Artery: A Cadaveric Study.

    PubMed

    Cancienne, Jourdan M; Werner, Brian C; Burrus, M Tyrrell; Kandil, Abdurrahman; Conte, Evan J; Gwathmey, Frank W; Miller, Mark D

    2017-03-10

    The purpose of this study was to use fluoroscopy to measure the distance between the transseptal portal and the popliteal artery under arthroscopic conditions with an intact posterior knee capsule, and to determine the difference between 90 degrees of knee flexion and full extension. The popliteal artery of eight fresh-frozen cadaveric knees was dissected and cannulated proximal to the knee joint. The posterolateral, posteromedial, and transseptal portals were then established at 90 degrees of flexion. A 4-mm switching stick was placed through the transseptal portal, and barium contrast was injected into the popliteal artery. A lateral fluoroscopic image was taken with the knee in 90 degrees of flexion and full extension, and the distance between the popliteal artery and the switching stick was measured and compared using a paired t-test. In knee flexion, the average distance between the transseptal portal and the anterior aspect of the popliteal artery for the eight cadaveric specimens was 12.0 mm ± 3.3 mm; in extension, this decreased to 9.0 mm ± 2.7 mm. The distance between the transseptal portal and popliteal artery was significantly higher at 90 degrees of knee flexion as compared with extension (p = 0.0005). The transseptal posterior knee arthroscopic portal must be carefully created due to the close proximity to the popliteal artery, and may be closer to the artery than previously reported in specimens with an intact posterior knee capsule. Creating the portal with the knee in flexion significantly displaces the popliteal artery away from the portal reducing the risk of arterial injury.