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Right Knee (right + knee)
Selected AbstractsReplacement of the medial tibial plateau by a metallic implant in a goat modelJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 4 2010Roel J.H. Custers Abstract The purposes of the present study were to explore the surgical possibilities for replacement of the medial tibial plateau by a metallic implant in a large animal model and to examine the implications for the opposing cartilage. In six goats, the medial tibial plateau of the right knee was replaced by a cobalt,chromium implant, using polymethylmethacrylate bone cement for fixation. The unoperated left knee served as a control. At 26 weeks after surgery, the animals were killed, and the joints evaluated macroscopically. Cartilage quality was analyzed macroscopically and histologically. Glycosaminoglycan content, synthesis, and release were measured in tissue and medium. All animals were able to move and load the knees without any limitations. Macroscopic articular evaluation scores showed worsening 26 weeks after inserting the implant (p,<,0.05). Macroscopic and histologic scores showed more cartilage degeneration of the opposing medial femoral condyle in the experimental knee compared to the control knee (p,<,0.05). Higher glycosaminoglycan synthesis was measured at the medial femoral condyle cartilage in the experimental knees (p,<,0.05). This study shows that the medial tibial plateau can be successfully replaced by a cobalt,chromium implant in a large animal model. However, considerable femoral cartilage degeneration of the medial femoral condyle was induced, suggesting that care must be taken introducing hemiarthroplasty devices in a human clinical setting for the treatment of postmeniscectomy cartilage degeneration of the medial tibial plateau. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:429,435, 2010 [source] Nonweight-bearing anterior knee laxity is related to anterior tibial translation during transition from nonweight bearing to weight bearingJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 3 2006Sandra J. Shultz Abstract We examined the relationship between anterior knee laxity (AKL), evaluated while the knee was nonweight bearing, and anterior translation of the tibia relative to the femur (ATT), evaluated when the knee transitioned from nonweight-bearing to weight-bearing conditions in response to an applied compressive load at the foot. Twenty subjects with normal knees (10 M, 10 F; 25.2,±,4.1 years, 169.8,±,11.5 cm, 71.6,±,16.9 kg) underwent measurements of AKL and ATT of the right knee on 2 days. AKL was measured at 133N with the KT-2000Ô. ATT was measured with the Vermont Knee Laxity Device and electromagnetic position sensors attached to the patella and the anteromedial aspect of the proximal tibia. Three trials for each measure were averaged and analyzed. Measurement consistency was high for both AKL (ICC,=,0.97; SEM,=,0.44 mm) and ATT (ICC,=,0.88; SEM,=,0.84 mm). Linear regression revealed that AKL predicted 35.5% of the variance in ATT (p,=,0.006), with a prediction equation of YATT,=,3.20,+,0.543(XAKL). Our findings suggest that increased AKL is associated with increased ATT as the knee transitions from nonweight-bearing to weight-bearing conditions. The potential for increased knee joint laxity to disrupt normal knee biomechanics during activities such as landing from a jump, or the foot strike phase of gait deserves further study. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:516,523, 2006 [source] Evaluation of a method to map tibiofemoral contact points in the normal knee using MRIJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 4 2004Jennifer M. Scarvell Abstract A technique using magnetic resonance imaging (MRI) is proposed for analysis of knee motion that is practical in the clinical situation. T1 weighted fast spin echo (FSE) and spoiled gradient echo (GE) sequences were compared to image both knees at 15° intervals from 0° to 90° flexion, while unloaded and loaded. The medial and lateral tibiofemoral contact points were mapped reliably using both FSE sequences and GE sequences with intra-class correlation(2,1) of 0.96 (CI 99% = 0.94,0.97) and 0.94 (CI 99% = 0.91,0.97), respectively. Results were consistent with the current literature on knee motion: the medial and lateral tibiofemoral contact pathways were different (F1.80 = 253.9, p < 0.0001) reflecting the longitudinal rotation of the knee, the loaded and unloaded knees were not different in the healthy knee (F1.80 = 0.007, p = 0.935), and the left and right knee were consistent for each individual (F1.80 = 0.005, p = 0.943). Therefore, right to left differences may be attributed to pathology. MRI analysis of knee kinematics as described by this technique of tibiofemoral contact point mapping provides a robust and reliable method of recording the tibiofemoral contact pattern of the knee. © 2003 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source] The intraoperative use of recombinant FVIIa in child with hemophilia A with antibodiesPEDIATRIC ANESTHESIA, Issue 8 2007DUSICA SIMIC MD Summary Patients with hemophilia A that developed inhibitors to FVIII represent a problem for bleeding control especially during surgical procedures. We report the use of bolus injections of rFVIIa during one intervention that included synoviectomy on the right knee, cholecystectomy and appendicectomy in a child with high titer of inhibitors to FVIII. rFVIIa was administered at the start (120 ,g·kg,1) and then every 2 h (90 ,g·kg,1) during the procedure. ,-aminocapronic acid was also administered as an antifibrinolytic every 3 h. We monitored aPTT (activated partial thromboplastin time) and PT (prothrombin time) and they were within reference values. Surgery lasted 7 h without significant hemorrhage. Postoperatively the dose of rFVIIa was slowly reduced and after ten days the patient was discharged home in good condition. In our case rFVIIa helped a child with hemophilia A with antibodies to undergo major surgery but each case should be treated individually and the cost of rFVIIa has also to be taken into account. [source] Serum levels of vitamin D, sunlight exposure, and knee cartilage loss in older adults: The Tasmanian older adult cohort studyARTHRITIS & RHEUMATISM, Issue 5 2009Changhai Ding Objective To determine the associations between serum levels of vitamin D, sunlight exposure, and knee cartilage loss cross-sectionally and longitudinally in older adults. Methods A total of 880 randomly selected subjects (mean age 61 years [range 51,79 years], 50% women) were studied at baseline, and 353 of these subjects were studied 2.9 years later. Serum levels of 25-hydroxyvitamin D (25[OH]D) were assessed by radioimmunoassay, and sunlight exposure was assessed by questionnaire. T1-weighted fat-suppressed magnetic resonance imaging (MRI) of the right knee was performed to determine knee cartilage volume and defects. Knee radiographic osteoarthritis (OA) and knee pain were also assessed. Results The mean 25(OH)D serum level was 52.8 nmoles/liter at baseline (range 13,119 nmoles/liter). Winter sunlight exposure and serum 25(OH)D level were both positively associated with medial and lateral tibial cartilage volume, and a serum 25(OH)D level <50 nmoles/liter was associated with increased medial tibiofemoral joint space narrowing (all P < 0.05). Longitudinally, baseline serum 25(OH)D level predicted change in both medial and lateral tibial cartilage volume (, = +0.04% per annum per nmole/liter for both; P < 0.05), and change in serum 25(OH)D level was positively associated with change in medial tibial cartilage volume. These associations were consistent in subjects with radiographic OA and knee pain and/or in women, but not in men or in subjects without radiographic OA or knee pain. Conclusion Sunlight exposure and serum 25(OH)D levels are both associated with decreased knee cartilage loss (assessed by radiograph or MRI). This is best observed using the whole range of 25(OH)D levels rather than predefined cut points and implies that achieving vitamin D sufficiency may prevent and/or retard cartilage loss in knee OA. [source] An investigation to examine the inter-tester and intra-tester reliability of the Rolimeter® knee tester, and its sensitivity in identifying knee joint laxityJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 6 2005Julian Hatcher Abstract Purpose: The purpose of this study is to evaluate the Rolimeter® knee tester (Aircast®, Europe) as reliable and clinically sensitive tool for identifying and quantifying knee joint laxity utilising a sample of both known ACLD and normal knees. Methods: Thirty matched subjects (15 known ACLD and 15 normal subjects) were tested for knee joint laxity using the Rolimeter®. Each subject was measured at both 90° and 30° of knee flexion, by each of the six investigators. This was then repeated again by all six investigators so that inter-tester and intra-tester reliability could be examined. Results: Results showed that there was good reliability between testers, and intra-tester reliability was good for both left and right knees in both 90° and 30° of flexion. Results also demonstrated a high level of sensitivity for determining knee joint laxity in ACLD compared to normal knees. Conclusion: The Rolimeter® knee tester is a reliable device for quantifying knee joint laxity, and is sensitive enough to identify anterior cruciate ligament deficiency. © 2005 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source] | ||||||||||