OBJECTIVETo summarize the detailed failure mechanisms of revision hip arthroplasties and related risk factors.

METHODSFrom November 1988 to July 2008 revision of total hip arthroplasties was performed in 327 patients. The medical history, clinical and imaging material and operation records were investigated.

RESULTSRegarding revision as the end point of the study, the reasons for 327 revision arthroplasties were aseptic loosening in 226 hips (69.1%), infection in 52 hips (15.9%), periprosthetic fracture in 22 hips (6.7%), instability in 17 hips (5.2%), stem fracture in 5 hips (1.5%) and liner dissociation in 5 hips (1.5%).

CONCLUSIONSThe main failure mechanisms of primary hip arthroplasties are aseptic loosening and infection of implants, which could be attributed to improper selection of operation indications and implants and limitations to surgical philosophy and technique.

Adult ; Aged ; Aged, 80 and over ; Arthroplasty, Replacement, Hip ; adverse effects ; Female ; Humans ; Male ; Middle Aged ; Periprosthetic Fractures ; Prosthesis Failure ; Reoperation ; Retrospective Studies ; Risk Factors ; Surgical Wound Infection ; Treatment Failure

Objective To establish a method for determination and optimize the extraction process of the content of plantamajoside in plantain.Methods Plantamajoside content was determined by HPLC.The effects of ethanol concentration, ethanol amount and extraction time on the extraction of plantamajoside from plantain were studied by orthogonal design.Results The calibration curve was linear (r=0.999 6) over the range of 12.52-125.10μg/ml.The average recovery was 98.57％ (RSD=1.45％).The optimum extraction process was as follows:60％ethanol, 10times volumes, extracted 2times, 1heach time.Conclusion The established method was simple, accurate and reproducible for determination of the content of plantamajoside in plantain.The optimal extraction process was stable and feasible.