Titanium Alloy Cage Implantation for the Treatment of Ischemic Necrosis of Femoral Head in Dogs

To study the effect of titanium alloy cage on the treatment of the ischemic necrosis of femoral head in dog, the model of the ischemic necrosis of femoral head was made with the liquid nitrogen in 15 hybrid adult dogs. The titanium alloy cage made of a hollow cylinder was driven into the subchondral bone of necrotic femoral head via central channel. The dogs were divided into 3 groups, each group was sacrificed 3, 6, 12 weeks after the operation respectively. No collapse of femoral head was observed after the operation. The position of the cages was good on radiograph. Microscopically, the cancellous bone of necrotic femoral head rebuilt gradually and grew into cage. After 12 weeks of creeping substitution, the cancellous bone filled up the hollow cavity and holes of the cages. It is concluded that the titanium alloy cage can provide structural support for the subchondral bone and prevent collapse and can be used for the treatment of the ischemic necrosis of femoral head.

Experimental study of changes of TNF-α in rabbits with steroid-induced avascular necrosis of femoral head

Objective: To explore the effect of tumor necrosis factor-α(TNF-α)on the occurrence of steroid-induced avascular necrosis of femoral head(SANFH). Methods: Twenty-four rabbits were firstly divided into void group (n=12) and model group (n=12) at random. Prednisone Acetate was injected to the model group(0.32 mg·kg^(-1)·d^(-1)). In the 6 th and 8 th week, two rabbits of the two groups were killed respectively to observe whether the model was successful. The level of TNF-α in serum of the residual rabbits of the two groups was examined in Radioimmunoassay method. Results: The level of TNF-α in model group is significantly higher than that in void group(P<0.001) under the premise of the model of SANFH success by histological observation. Conclusion: The rise of level of TNF-α may be one of the most important factors in the occurrence of SANFH.

Clinical study on the related markers of blood coagulation in the patients with ANFH after SARS

The aim of this research was to investigate the blood coagulation function in the patients with avascular necrosis of the femoral head(ANFH)after severe acute respiratory syndrome(SARS).The expression of CD31,CD61,CD62p,CD63 and PAC-1 on platelet membrane was measured respectively by flowcytometry,and the plasma prothrombin time(PT),activated partial thromboplastin time(APTT),thrombin time(TT)and fibrinogen(Fbg)were mea-sured by blood clotting instrument in 26 patients with ANFH after SARS and in 17 healthy adults.The expression of CD31,CD61,CD 62p,CD63 and PAC-1 on platelet membrane in 26 patients was all lower than that in 17 healthy subjects(P<0.01).The levels of PT,APTT,TT and Fbg in 26 patients were all normal.There is no significant difference(P>0.05)in those markers between patients and 17 healthy adults.The blood may not be in hypercoagulable state in patients with ANFH after SARS.

Horizontal platform supported total hip replacement

Objective To investigate the effect of horizontal platform supported (HPS) prosthesis on cementless total hip replacement for surgical treatment of arthritis in a long-term follow-up study.Methods Clinical and radiographic follow-up of 65 consecutive primary cementless porous coated HPS total hip replacements, which were implanted in 60 patients between 1982 and 1989, was carried out.Results The 53 hips in 50 patients were evaluated both clinically and radiographically. The average follow-up was 6.8 years (range: 5 to 12 years). According to the Harris hip score, 52 (98%) of the hips had sustained an excellent or good result with an average score of 92. At the time of final assessment, no patient experienced anterior thigh pain. There were two revisions performed early in the series due to technical failures. Radiographically, osteolysis and bone re-modelling were assessed. Conclusion The findings suggest that the clinical and radiographic results after cementless total hip replacement for primary hip arthroplasty may be favourably influenced by the use of the proximal stress loaded HPS femoral component.