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ABSTRACT: Mechanical loading plays an important role not solely in cartilage development, but also in cartilage degeneration. Its adaptation behavior to mechanical loading has not been clearly delineated. The aim of the study was to examine the effect of different running modes (with different muscle contraction types) on morphological, biochemical, and mechanical properties of articular cartilage in the knee of growing rats. Thirty-six female Sprague-Dawley rats were randomly assigned into a nonactive age-matched control (AMC), level (LEVEL), and 20° downhill (DOWN) running group (n = 12 each). Running groups were trained on a treadmill for 30 min/day, 5 days/week for 6 weeks. Immunohistochemical staining and analysis of expression for collagen II, collagen IX, cartilage oligomeric matrix protein (COMP), and matrilin-3, histomorphometry of femoral cartilage height and femoral COMP staining height, and indentation testing of tibial articular cartilage were performed. Rats subjected to downhill running showed a significantly (P = 0.015) higher COMP staining height and a tendentially (P = 0.084) higher cartilage height in the high-weight bearing area of femoral articular cartilage. Cartilage thickness, mechanical properties, and expression of cartilage network proteins in tibial cartilage remained unaffected by different running modes. Our data suggest that joint loading induced by eccentric muscle contractions during downhill running may lead to a site-specific adaptation.
Scandinavian Journal of Medicine and Science in Sports 08/2012; · 2.87 Impact Factor
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ABSTRACT: To investigate (1) the effect of running and drop landing interventions on knee cartilage deformation and serum cartilage oligomeric matrix protein (COMP) concentration and (2) if the changes in cartilage volume correlate with the changes in serum COMP level.
Knee joint cartilage volume and thickness were determined using magnetic resonance imaging (MRI) as well as COMP concentration from serum samples before and after in vivo loading of 14 healthy adults (seven male and seven female). Participants performed different loading interventions of 30 min duration on three different days: (1) 100 vertical drop landings from a 73 cm high platform, (2) running at a velocity of 2.2m/s (3.96 km), and (3) resting on a chair. Blood samples were taken immediately before, immediately after and 0.5h, 1h, 2h and 3h post intervention. Pre- and post-loading coronal and axial gradient echo MR images with fat suppression were used to determine the patellar, tibial and femoral cartilage deformation.
Serum COMP levels increased immediately after the running (+30.7%, pre: 7.3U/l, 95% confidence interval (CI): 5.6, 8.9, post: 9.1U/l, 95% CI: 7.2, 11.0, P=0.001) and after drop landing intervention (+32.3%, pre: 6.8U/l, 95% CI: 5.3, 8.4; post: 8.9U/l, 95% CI: 6.8, 10.9, P=0.001). Cartilage deformation was more pronounced after running compared to drop landing intervention, with being significant (volume: P=0.002 and thickness: P=0.001) only in the lateral tibia. We found a significant correlation (r(2)=0.599, P=0.001) between changes in serum COMP (%) and in cartilage volume (%) after the drop landing intervention, but not after running.
In vivo exercise interventions differentially regulate serum COMP concentrations and knee cartilage deformations. The relation between changes in COMP and in cartilage volume seems to depend on both mechanical and biochemical factors.
Osteoarthritis and Cartilage 05/2011; 19(8):1003-10. · 3.90 Impact Factor
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ABSTRACT: Background Osteoarthritis (OA) is a progressive degenerative disease of all joint structures, affecting over 50% of the population over the age of 65 in the US. Joint injury, a common outcome of sport participation, and high impact loading, such as that experienced in landing and running, are associated with an increased risk of cartilage degeneration and OA development. However, joint loading is also important to cartilage matrix health. The relationship between mechanical loading and joint degeneration is not clear. Objective To investigate the response of biological markers of cartilage metabolism to moderate cyclical and high impact loading activities. Design Comparative cohort study. Setting High level athletes. Participants 10 impact athletes (five women and five men) and 14 adult non-athletic controls (seven women and seven men). Interventions Data were collected and compared between three experimental conditions: complete rest; moderate cyclical loading (slow jog); and high impact loading (landing). The duration of intervention was 30 min and subjects were supervised throughout the intervention. Main outcome measurements Blood samples were collected from each subject at baseline and 30, 60, 120 and 240 min after three interventions. Blood samples were allowed to clot, centrifuged to separate the serum and aliquots were stored at -80° until testing. Serum concentrations of glucosaminoglycans, C-propeptide of collagen II (CP2), cleavage of collagen II (C2C) and cartilage oligomeric matrix protein (COMP) were evaluated using commercially available Enzyme Linked Immunosorbent Assay kits. Results A significant change in serum biomarker concentration in response to the loading intervention was observed for COMP. Conclusion The results of this study suggest that serum CP2 and C2C concentrations were not influenced by the loading interventions at the analysed time points. However, COMP increased immediately after the loading interventions. Future studies should investigate the role of biomarkers as a diagnostic tool for evidence based workload assessment.
British journal of sports medicine 04/2011; 45(4):326. · 2.55 Impact Factor
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ABSTRACT: The purpose of the study was to investigate whether a relationship between the loading mode of physical activity and serum cartilage oligomeric matrix protein (COMP) concentration exists and whether the lymphatic system contributes to COMP release into the serum. Serum COMP levels were determined in healthy male subjects before, after and at 18 further time points within 7 h at four separate experimental days with four different loading interventions. The loading intervention included high impact running exercise, slow but deep knee bends, and lymphatic drainage of 30 min duration, respectively, and a resting protocol. The serum COMP levels were measured using a commercially available quantitative enzyme-linked immunosorbent assay. An increase (p < 0.001) in serum COMP concentration was detected immediately after 30 min running exercise. Slow but deep knee bends did not cause any significant changes in serum COMP levels. Lymphatic drainage also had no effect on the serum COMP concentration. After 30 min of complete rest the serum COMP level was significantly (p = 0.008) reduced. The elevation of COMP serum concentration seems to depend on the loading mode of the physical activity and to reflect the extrusion of COMP fragments from the impact loaded articular cartilage or synovial fluid.
Arbeitsphysiologie 10/2010; 110(3):651-7. · 2.15 Impact Factor
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ABSTRACT: Pathologic bone fractures in cryosurgery of bone tumors have been described in literature. This study utilizing a sheep model should prove the possible reduction of potential fracture while using a new miniature cryoprobe minimizing tissue damage and providing accurate control of the ablation process. Furthermore, postoperative histological changes should be investigated and the results correlated with the stability trials.
In 24 sheep, ablation of the femur and the tibial bone on one side was carried out. Ablation of the right femur was limited to an area of 2 cm(2) with single cortical bone, whereas at the left tibia the whole proximal tibial plateau was included. The other side served as a control entity without cryoablation. After a period of 2, 4, and 6 months postoperative investigation of bending resistance of the femoral bone and of compression resistance of the tibial bone as well as histological findings were done in eight animals each.
After 2 months there was a significant difference (P < 0.05) regarding compression resistance between the treated and the contralateral tibia, whereas the bending resistance in the treated femur was slightly lower than on the contralateral side. After 4 and 6 months the cryo-treated part showed a tendency towards weakness. Histological findings showed bone necrosis with slight beginning repair after 2 months. Four and six months later, bone necrosis still existed with increasing development of woven bone and conversion into lamellar bone.
A thorough control of the freezing process and the low iatrogenous weakening of the bone due to placing the probe when modern miniature cryoprobes are used can minimize the risk of pathological postoperative fractures. However, at least 2 months after operation there is histological proof of bone healing with appropriate reduction of bone stability, which should be considered for the clinical application of this new technique.
Archives of Orthopaedic and Trauma Surgery 06/2009; 129(6):857-62. · 1.37 Impact Factor
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ABSTRACT: The incidence of spontaneous fractures after cryosurgical treatment is described in the literature. The purpose of this study in the sheep model was to analyze the possibility of minimizing the potential risk of bone failure using a new miniature cryoprobe with minimal tissue traumatism and exact control of the ablation. In each of 24 sheep ablations at the right femur and left tibia were performed by drilling. The ablation at the femur was restricted to an area of 2 cm(2) of only one cortical bone, whereas at the proximal tibia the whole tibial plateau was included. The opposite side, which was treated with analog drillings without cryoablation, served as control. The ultimate bending strength of the femur and the ultimate compression strength of the tibia were examined 2, 4, and 6 months after the operation. After 2 months there was a significant difference ( p<0.05) in the ultimate compression strength between the treated and untreated tibiae, whereas the ultimate bending strength of the treated femora tended to be lower. After 4 and 6 months the side treated with cryosurgery was only marginally weaker than the untreated side. Spontaneous fractures were not observed during the whole experimental period. The good controllability of the freezing procedure and the low iatrogenic weakening of the bone using a modern miniature cryoprobe minimizes the risk of pathological postoperative fractures. After ablation of larger bone sections, the treated extremity should be partially unloaded or managed by osteosynthesis for at least 3 months.
Der Unfallchirurg 03/2004; 107(2):113-7. · 0.61 Impact Factor
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ABSTRACT: Das Auftreten von Spontanfrakturen nach kryochirurgischer Behandlung von Knochengewebe ist in der Literatur beschrieben. Durch diese Studie am Schafmodell sollte geprft werden, ob die potentielle Bruchgefahr durch Verwendung einer neuartigen Miniaturkryosonde mit minimaler Gewebetraumatisierung und exakter Kontrolle des Ablationsvorgangs gemindert werden kann.Bei 24 Schafen wurde je eine Ablation an Femur und Tibia einer Seite ber eine Bohrung vorgenommen. Die Ablation am rechten Femurknochen wurde auf eine Flche von 2cm2 unter Erfassung nur einer Kortikalis beschrnkt, whrend an der linken Tibia der gesamte proximale Tibiakopf mit erfasst wurde. Die Gegenseite diente ber analoge Bohrungen ohne Kryoablation als Kontrolle. Bei je 8 Tieren erfolgte 2, 4 bzw. 6Monate postoperativ die Untersuchung der Biegefestigkeit der Femora und der Kompressionsfestigkeit der Tibiae .Nach Ablauf von 2Monaten war ein signifikanter Unterschied (p<0,05) in der Kompressionsfestigkeit zwischen behandelten und unbehandelten Tibiae vorhanden, whrend die Biegefestigkeit der behandelten Femora nur tendenziell niedriger war als die der Kontrollseite. Nach 4 und 6Monaten war die kryobehandelte Seite noch tendenziell geschwcht. Spontanfrakturen wurden ber den gesamten Versuchsablauf nicht beobachtet.Die gute Kontrollierbarkeit des Friervorgangs sowie die geringe iatrogene Schwchung des Knochens bei der Sondenplatzierung unter Verwendung moderner Miniaturkryosonden minimiert das Risiko pathologischer postoperativer Frakturen. Bei Ablation grerer Knochenabschnitte sollte die behandelte Extremitt dennoch ber mindestens 3Monate teilentlastet oder osteosynthetisch versorgt werden.The incidence of spontaneous fractures after cryosurgical treatment is described in the literature. The purpose of this study in the sheep model was to analyze the possibility of minimizing the potential risk of bone failure using a new miniature cryoprobe with minimal tissue traumatism and exact control of the ablation.In each of 24 sheep ablations at the right femur and left tibia were performed by drilling. The ablation at the femur was restricted to an area of 2cm2 of only one cortical bone, whereas at the proximal tibia the whole tibial plateau was included. The opposite side, which was treated with analog drillings without cryoablation, served as control. The ultimate bending strength of the femur and the ultimate compression strength of the tibia were examined 2, 4, and 6months after the operation.After 2months there was a significant difference (p<0.05) in the ultimate compression strength between the treated and untreated tibiae, whereas the ultimate bending strength of the treated femora tended to be lower. After 4 and 6months the side treated with cryosurgery was only marginally weaker than the untreated side. Spontaneous fractures were not observed during the whole experimental period.The good controllability of the freezing procedure and the low iatrogenic weakening of the bone using a modern miniature cryoprobe minimizes the risk of pathological postoperative fractures. After ablation of larger bone sections, the treated extremity should be partially unloaded or managed by osteosynthesis for at least 3months.
Der Unfallchirurg 01/2004; 107(2):113-117. · 0.61 Impact Factor
