LABORATORY AND ANIMAL STUDIES

The Study on Histopathological Changes of Femoral Heads for Osteocyte Apoptosis of Osteonecrosis Patients
H Liu, T Dong
Department of Orthopaedic Surgery, The First Teaching Hospital of Soochow University, Soochow, China

Purpose: To study the pathological changes of osteocytes mainly for cell apoptosis in osteonecrotic femoral heads.

Method: The femoral heads removed from patients for hip replacements (6 steroid-induced cases, 8 alcohol-induced cases, and 3 cases resulted from femur neck fracture ) were studied .Besides the routine microscopic study after the HE (haematoxylin and easin) staining,in order to detect the apoptosis of osteocytes,the methyl green-prynoin staining and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling, namely TUNEL method were adopted. The specimens were also studied under electronic microscope.

Results: There were a large number of osteocytes,chondrocytes and marrow cells in steroid-induced and alcoholic cases showing apoptotic changes, while only a few in cases after femoral neck fracture. Apoptotic cells of the alcoholic group were less than that of the steroid-induced group, which is significant statistically (P<0.05).

Conclusion: The apoptosis occurs in either steroid-induced or alcoholic osteonecrosis which may be the initial pathological changes of femoral head osteonecrosis. The pathogenesis in nontraumatic osteonecrosis of the femoral head caused by steroid and alcohol abuse may be different in some aspects from that caused by femoral neck fracture which is soley caused by ischemia of the femoral head.