[Quantitative study of therapeutic efficacy on early intervention of hyperbaric oxygen to model of steroid-induced avascular osteonecrosis of femoral head by multi-slice perfusion imaging].
OBJECTIVE
To quantitatively evaluate the hemodynamic status in animal models of steroid-induced avascular osteonecrosis of femoral head (SANFH) by multislice CT (MSCT) perfusion imaging, and estimate the therapeutic efficacy on early intervention of hyperbaric oxygen (HBO) to improve the region blood flow (rBF) of ischemic femoral head.


METHODS
Forty-eight New Zealand male rabbits were injected with Escherichia coli endotoxin and methyl-prednisolone to establish SANFH models and then divided into 3 subgroups to undergo MSCT to measure the rBF, regional blood volume (rBV), and mean transit time (MTT) to obtain perfusion maps at the femoral head epiphysis, metaphysic, and neck of femur, and then were killed to undergo histological examination of the bilateral femoral heads 2, 4, and 6 weeks later respectively (Groups M(2), M(4), and M(6)). Twenty-four rabbits underwent HOB treatment after the second injection of E. c. endotoxin for 1-3 courses respectively (Groups H(1), H(2), and H(3)), and then underwent MSCT and pathological examination as described above. Eight rabbits were used as controls (Group N).


RESULTS
(1) The rBF values of Groups M(2), M(4), and M(6) were all significantly lower than that of Group N (P < 0.001, < 0.001, and < 0.002). The rBF value of femoral head epiphysis of Group M(2) was remarkably lower than that of Group N, decreased to the lowest in Group M(4), and re-increased in Group M(6). The rBV value demonstrated similar change pattern in femoral head epiphysis. The MTT values of Groups M(2) and M(4) were longer than that of Group N, and then re-decreased in Group M(6). (2) It did differ significantly between the perfusion data of different femoral head anatomic regions in Groups M(2), M(4), M(6) and N (rBF: F = 52.190, P < 0.001; rBV: F = 42.677, P < 0.001; MTT: F = 3.09, P = 0.048). The changes of the perfusion data in femoral head epiphysis were more significant than those in other anatomic regions. (3) There were no statistically significant differences in the rBF value of the femoral head epiphysis and metaphysis (F = 2.081, P = 0.115; F = 1.142, P = 0.341), in the rBV value of the femoral metaphysis and neck of femur (F = 2.642, P = 0.059; F = 1.568, P = 0.209), and the MTT value of all the anatomic regions (F = 1.111, P = 0.347) among Groups H(1), H(2), H(3), and N. The rBF values of Groups H(1), H(2), and H(3) were statistically higher than those of the corresponding phase model groups (all P < 0.05).


CONCLUSIONS
Able to detect hemodynamic status of femoral head, MSCT perfusion imaging technique may be used in the early detection of SANFH. Early intervention of HBO therapy can improve the blood perfusion of femoral head.
Yang
Jin-cai
JC
Department of Orthopedics, Chaoyang Hospital, Capital University of Medical Sciences, Beijing 100020, China.
Pan
Zhen-yu
ZY
Gu
Hua
H
Li
Nan
N
Qian
Xiao-jun
XJ
Zhai
Ren-you
RY
Wu
Lian-hua
LH
Gao
Chun-jin
CJ
D000818:Animals; D001810:Blood Volume; D004195:Disease Models, Animal; D005271:Femur Head Necrosis / Q000139:chemically induced / Q000503:physiopathology* / Q000628:therapy*; D006931:Hyperbaric Oxygenation; D008297:Male; D055420:Perfusion Imaging; D011817:Rabbits; D014057:Tomography, X-Ray Computed / Q000379:methods