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Cell proliferation in the growth plate after application of an axial distraction force
Abstracts
387
A METHODFOR MEASURING CONYACTPRESSURE INSTANTANEOUSLYIN AKIICUIAR JOINT Hitoshi Inaba, Michio Arai and Kyoji Okada Department of Orthopaedic Surgery. Akita University School of Medicine, Akita City, 010, JAPAN. The purpose of this investigation vas to detail a nev method for instantaneous measuring of contact pressures directly and evaluate contact pressures measured by it. For three fresh knee specimens were measurement of contact pressures on the articular cartilage, A rectangular parallepiped vith cartilage cut out from each femoral condyle and studied. the medial or lateral plateau divided from a tibia vere fixed to the holders vith gypsand After drilling small holes in the tibia1 plateau, pipes vere inserted in were articulated. the cartilage of the tibia from the underlying subchondral bone and vere opened to the joint space. Both of miniature transistor pressure transducer and Bourdon tube pressure gauge Physiological saline vas used as pressure medium were connected simultaneously to the pipe. pressure measured by this method vas leakage pressure from the at 10 MPa. The contact The contact pressure vas measured during cyclical loading contact articular surfaces. following change in relative position betveen the femoral and tibia1 components. To assess the value of the contact pressure measured by the nev system, sensitive sensor sheets vere used. There vas scarcely stress concentration due to the insertion of pipe in the cartilage. The contact pressures by the method correlated statistically significantly vith those by sensitive sensor sheets and vlth average contact pressure (load/contact area). The linear The method is applicable to many model yield high coefficient of correlation between them. articular joints under various loading conditions for elucidation of cartilage pathomechanics and pa thogenes is.
A METHOD FOR MEASURING
CONTACT PRESSURE INSTANTANEOUSLY IN ARTICULAR JOINT Hftoshi Inaba, Michto Arai and Kyoji Okada Department of Orthopaedic Surgery, Akita University School of Medicine. Akita City, 010. JAPAN. The purpose of this investigation vns to detail a new method for instantaneous measuring of Contact pressures d.reCtly and evaluate contact pressures measured by it. For measurement of contact pressures on the articular cartilage, three fresh knee specfmens were studied. A rectangular pnrnllcpipcd with cartilage cut out from each femoral condyle and the medial or lateral plateau dfvfded from a tibia were fixed to the holders with gypsum and were articulated. After drilling small holes in the tibia1 plateau, pipes were inserted in the cartilage of the tibia from the underlying subchondral bone and were opened to the joint space. Both of miniature transistor pressure transducer and Bourdon tube pressure gauge were connected simultaneously to the pipe. Physiological saline was used as pressure medium at 10 MPa. The contact pressure measured by this method was leakage pressure from the contact articular surfaces. The contact pressure vas measured during cyclical loading following change in relative position between the femoral and tibia1 components. To assess the value of the contact pressure measured by the nev system, sensitive sensor sheets were There was scarcely stress concentration due to the insertion of pipe in the cartilage. used. The contact pressures by the method correlated statistically significantly with those by sensitive sensor sheets and with average contact pressure (load/contact area). The linear model yield high coefficient of correlation between them. The method is applicable to many artfcular joints under various loading conditions for elucidation of cartilage pathomechanics and pat hogenesis.
CELL PROLIFERATION IN THE GROWTH PLATE AFTER APPLlCATlON OF AN AXlAL DISTRACTION FORCE. Suneel S. Apte, John Kenwright,and Mervyn Evans? Nuffleld Dept. of Orthopaedlc Surgery, and Oxford Orthopaedlc Engineering Centref Nuffield Orthopaedlc Centre, Headington, Oxford OX3 7LD, UK. The effect of application of an axial dlstractlon force to growth plate cartilage was studled using an external flxator frame applied to the right upper tibia1 growth plate of 6 week old NZW rabblts, (n= IO). The contralateral growth plate served as control, and 5 rabblts underwent sham operations. Precallbrated springs on the external fixator permitted the application and measurement of the forces used. A force of 10 Newtons was applied continuously for 10 days.Histomorphometric evaluation of growth plate parameters and trltIated thymldlne autoradlography were used to study the effects of dlstractlon. Load mot-11torlng suggested that there had been no fracture through the growth plate and this was conflrmed by histology.Statistically significant Increases in longltudlnal bone growth,(p
387
A METHODFOR MEASURING CONYACTPRESSURE INSTANTANEOUSLYIN AKIICUIAR JOINT Hitoshi Inaba, Michio Arai and Kyoji Okada Department of Orthopaedic Surgery. Akita University School of Medicine, Akita City, 010, JAPAN. The purpose of this investigation vas to detail a nev method for instantaneous measuring of contact pressures directly and evaluate contact pressures measured by it. For three fresh knee specimens were measurement of contact pressures on the articular cartilage, A rectangular parallepiped vith cartilage cut out from each femoral condyle and studied. the medial or lateral plateau divided from a tibia vere fixed to the holders vith gypsand After drilling small holes in the tibia1 plateau, pipes vere inserted in were articulated. the cartilage of the tibia from the underlying subchondral bone and vere opened to the joint space. Both of miniature transistor pressure transducer and Bourdon tube pressure gauge Physiological saline vas used as pressure medium were connected simultaneously to the pipe. pressure measured by this method vas leakage pressure from the at 10 MPa. The contact The contact pressure vas measured during cyclical loading contact articular surfaces. following change in relative position betveen the femoral and tibia1 components. To assess the value of the contact pressure measured by the nev system, sensitive sensor sheets vere used. There vas scarcely stress concentration due to the insertion of pipe in the cartilage. The contact pressures by the method correlated statistically significantly vith those by sensitive sensor sheets and vlth average contact pressure (load/contact area). The linear The method is applicable to many model yield high coefficient of correlation between them. articular joints under various loading conditions for elucidation of cartilage pathomechanics and pa thogenes is.
A METHOD FOR MEASURING
CONTACT PRESSURE INSTANTANEOUSLY IN ARTICULAR JOINT Hftoshi Inaba, Michto Arai and Kyoji Okada Department of Orthopaedic Surgery, Akita University School of Medicine. Akita City, 010. JAPAN. The purpose of this investigation vns to detail a new method for instantaneous measuring of Contact pressures d.reCtly and evaluate contact pressures measured by it. For measurement of contact pressures on the articular cartilage, three fresh knee specfmens were studied. A rectangular pnrnllcpipcd with cartilage cut out from each femoral condyle and the medial or lateral plateau dfvfded from a tibia were fixed to the holders with gypsum and were articulated. After drilling small holes in the tibia1 plateau, pipes were inserted in the cartilage of the tibia from the underlying subchondral bone and were opened to the joint space. Both of miniature transistor pressure transducer and Bourdon tube pressure gauge were connected simultaneously to the pipe. Physiological saline was used as pressure medium at 10 MPa. The contact pressure measured by this method was leakage pressure from the contact articular surfaces. The contact pressure vas measured during cyclical loading following change in relative position between the femoral and tibia1 components. To assess the value of the contact pressure measured by the nev system, sensitive sensor sheets were There was scarcely stress concentration due to the insertion of pipe in the cartilage. used. The contact pressures by the method correlated statistically significantly with those by sensitive sensor sheets and with average contact pressure (load/contact area). The linear model yield high coefficient of correlation between them. The method is applicable to many artfcular joints under various loading conditions for elucidation of cartilage pathomechanics and pat hogenesis.
CELL PROLIFERATION IN THE GROWTH PLATE AFTER APPLlCATlON OF AN AXlAL DISTRACTION FORCE. Suneel S. Apte, John Kenwright,and Mervyn Evans? Nuffleld Dept. of Orthopaedlc Surgery, and Oxford Orthopaedlc Engineering Centref Nuffield Orthopaedlc Centre, Headington, Oxford OX3 7LD, UK. The effect of application of an axial dlstractlon force to growth plate cartilage was studled using an external flxator frame applied to the right upper tibia1 growth plate of 6 week old NZW rabblts, (n= IO). The contralateral growth plate served as control, and 5 rabblts underwent sham operations. Precallbrated springs on the external fixator permitted the application and measurement of the forces used. A force of 10 Newtons was applied continuously for 10 days.Histomorphometric evaluation of growth plate parameters and trltIated thymldlne autoradlography were used to study the effects of dlstractlon. Load mot-11torlng suggested that there had been no fracture through the growth plate and this was conflrmed by histology.Statistically significant Increases in longltudlnal bone growth,(p