THE ABILITY OF REPERFUSION OFF THE EPIPHY SIS OF THE FEMORAL-HEAD AFTER ISCHEMIA - AN EXPERIMENTAL-STUDY

Citation
T. Schneider et al., THE ABILITY OF REPERFUSION OFF THE EPIPHY SIS OF THE FEMORAL-HEAD AFTER ISCHEMIA - AN EXPERIMENTAL-STUDY, Zeitschrift fur Orthopadie und Ihre Grenzgebiete, 136(2), 1998, pp. 132-137
Citations number
30
Categorie Soggetti
Orthopedics
ISSN journal
00443220
Volume
136
Issue
2
Year of publication
1998
Pages
132 - 137
Database
ISI
SICI code
0044-3220(1998)136:2<132:TAOROT>2.0.ZU;2-L
Abstract
Purpose of the study: The aim of this study was to evaluate bone blood flow of the proximal femur during experimentally induced ischemia and to document the ability of epiphyseal and metaphyseal reperfusion. Me thods: 11 pigs (danish landrace) were used to investigate the effect o f tamponade by increased joint pressure (Dextran 70) on the perfusion of the femoral head. Additional 8 pigs were used as control. The blood flow in the hip joint was studied by means of the microsphere techniq ue. The flow was determined before, during and after intraarticular pr essure Increase. With the ''radioactive tracer microsphere'' - method the blood now of the epiphysis, metaphysis and proximal femoral cortic alis could be measured. Results: In the epiphyseal femoral head the in itial blood flow rate, 11.7 ml/min/100 g, was not significant differen t from that of the control side (11.1 ml/min/100 g). The blood flow de creased in the ischemic phase to 1.8 ml/min/100 g followed by reperfus ion to 13.5 ml/min/100 g (p < 0.01). The bone blood flow of reperfusio n was not significant different from that of the initial blood flow ra te but in 2 cases a ''blow out'' of the epiphyseal bone blood flow was seen. The proximal femoral metaphysis showed the highest of the measu red intraosseous flow rates (17.9 resp. 23.3 ml/min/100 g). During isc hemia and reperfusion of the epiphysis bone blood flow of the metaphys is remained the same. The proximal femoral corticalis showed the lowes t of the measured intraosseous flow rates. The operated (10.1 ml/min/1 00 g) and contralateral hip side (11.7 ml/min/100 g) showed no signifi cant differences in the initial blood flow rate. During ischemia and r eperfusion the blood flow of the proximal corticalis showed no signifi cant difference to the initial blood flow corresponding to the metaphy sis. Conclusions. Our study demonstrates disturbances of the circulati on of different regions of the femoral head during intraarticular pres sure increase and following pressure decrease of the growing pig. 2 '' blow outs'' document a vulnerable proximal epiphysis already after a 6 -hour ischemia. Additional minor ''bone quality'' in cases of certain diseases (kidney transplantation, leukemia) and special administration of drugs (corticosteroids) seem to create an additional vulnerability of the proximal femoral head. The experiment proves to be a reliable model for decreasing the blood now of the growing epiphysis temporaril y and to document the beginning of normal reperfusion. With this model it is possible to examine the vulnerability of the epiphyseal perfusi on after different deseases and under the influence of different medic ation.