OBJECTIVE:To investigate the femoral bone remodeling and long-term effectiveness of total hip arthroplasty (THA) with anatomic medullary locking (AML) prosthesis. METHODS:The clinical data of 24 cases (26 hips) who were treated with THA with AML prosthesis between November 1997 and January 2003 were retrospectively analyzed. There were 12 males and 12 females with an age of 32-69 years (mean, 53.7 years). There were 5 cases (5 hips) of avascular necrosis of the femoral head, 6 cases (7 hips) of secondary osteoarthritis of the hip dysplasia, 6 cases (6 hips) of femoral neck fracture, 2 cases (2 hips) of primary osteoarthritis, 3 cases (3 hips) of revision surgery, 1 case (2 hips) of ankylosing spondylitis, 1 case (1 hip) of femoral head fracture. The patients were followed up at immediate, 6 weeks, 3 months, 6 months, 1 year, and then every year after operation for imaging evaluation (X-ray film was taken immediately after operation to evaluate the femoral isthmus compression, Engh standard was used to evaluate the biological fixation of the femoral shaft prosthesis, and Brooker method was used to evaluate the occurrence of heterotopic ossification); bone reconstruction evaluation [reconstruction of prosthesis and bone interface (type of bone reaction, Gruen zone, incidence, and occurrence time were recorded), reconstruction of bone around prosthesis (proximal femur stress shielding bone absorption was evaluated according to Engh and Bobyn methods, and bone mineral density change rate was measured)]; clinical efficacy evaluation [Harris score for efficacy, visual analogue scale (VAS) score for thigh pain]. RESULTS:All patients were followed up 15 years and 2 months to 20 years and 4 months, with a median of 16 years and 6 months. At immediate after operation, 24 hips (92.3%) had good femoral isthums compression, 24 hips (92.3%) had good bone ingrowth. Heterotopic ossification occurred in 2 patients with degree 1, 2 patients with degree 2, and 1 patient with degree 3 at 3-6 months after operation. Hyperplastic bone reactions were more common in Gruen 2, 3, 4, 5, 6, 10, 11, and 12 zones, mainly occurring at 6-20 months after operation, with the incidence of 3.8%-69.2%, with the highest incidence of spot welding. All absorptive bone reactions were osteolysis, which was common in Gruen 1 and 7 zones, and mainly occurred at 8 years after operation, with an incidence of 42.3%. No clear line (area) or enlarged sign of medullary cavity was observed. Twenty-one hips (80.8%) had 1 degree stress shieding, and 5 hips (19.2%) had 2 degree stress shieding. It mainly occurred at 10-24 months after operation in Gruen 1 and 7 zones. Dual energy X-ray absorptiometry showed that bone mineral density mainly decreased in Gruen 1, 2, 6, and 7 zones, mainly increased in Gruen 3, 4, and 5 zones. Bone mineral density loss progressed slowly after 2 years of operation, and it was stable in 5-8 years, but decreased rapidly in 8-9 years, and stabilized after 10 years. The Harris score increased from 51.1±6.2 before operation to 88.3±5.1 at last follow-up ( t=-21.774, P=0.000). Mild thigh pain occurred in only 2 cases (7.7%) with the VAS score of 2. No aseptic loosening or revision of femoral prosthesis occurred during the follow-up. CONCLUSION:The application of AML prosthesis in THA has a good bone remodeling and a good long-term effectiveness.

BACKGROUND:Osteosarcoma is a primary malignant bone tumor that frequently occurs in adolescents and children, its high aggressiveness and rapid metastasis often resulting in poor prognoses. In previous studies, Prazosin has been shown to possess anti-proliferative properties against prostate cancer and glioblastoma cells. In our study, we investigated Prazosin's underlying mechanisms and its effects on the biological behaviors of osteosarcoma cells.METHODS:Osteosarcoma cell lines MG63 and 143B were treated with different concentrations of Prazosin, and a CCK8 assay assessed its effect on cell viability. Colony formation, Transwell and flow cytometry assays were used to examine its effects on cell proliferation, cell migration, and cell invasion and apoptosis, respectively. The expression of relevant proteins was then examined using western blotting.RESULTS:Our data showed that Prazosin dose-dependently reduced the viability of MG63 and 143B cells and significantly inhibited their clonogenic ability. Moreover, Prazosin attenuated the cell migration and invasion abilities of MG63 and 143B cells when compared with the NC group. It also accelerated cell apoptosis in mitochondrial pathways by regulating Bcl-2/Bax axis and caspase 3. Furthermore, Prazosin treatment inactivated the Akt/mTOR pathway by down-regulating Akt and mTOR phosphorylation (p-Akt, p-mTOR) and the expression of P70 and cyclin D1.CONCLUSIONS:Our data highlights the fact that Prazosin inhibits cell growth, inhibits the motility of osteosarcoma cells, and promotes apoptosis, suggesting that Prazosin is a potential anti-cancer agent in osteosarcoma therapy.