[Objective]To estimate the clinical effects of total hip arthroplasty(THA),bipolar and unipolar hemiarthroplasty for the treatment of femoral neck fractures(FNF) in the elderly.[Method]From February 1990 to February 2005,a follow-up study was done in 567 patients with femoral neck fractures in the elderly.The patients were divided into THA(n=275),bipolar hemiarthroplasty(n=195) and unipolar hemiarthroplasty(n=97) groups.The follow-up duration was from 3 to 15 years with an average of 8.5 years.The operation time,blood loss,volume of drainage,hospitalization time,complications and functional rehabilitation were compared.[Result]There were no statistical differences in the operation time,blood loss and volume of drainage between unipolar and bipolar hemiarthroplasty groups.There were no statistical differences in hospitalization time among the three groups.Compared with bipolar hemiarthroplasty,THR had a longer operation time and more blood loss,but had a higher functional scores and a lower rate of pain.Unipolar hemiarthroplasty had a lower functional scores and a higher rate of pain.[Conclusion]THR is especially suitable for those who are younger and active,bipolar hemiarthroplasty is suited to elderly patients,unipolar hemi-arthroplasty should be avoided because of its complications.

Objective:To establish an animal model of trans-sutural distraction osteogenesis in SD rats.Methods:A self-designed V-shaped distraction device(distractor)was fabricated with the traction force(N)of 0,1.3,2.2,3.0,4.3 and 5.0 corresponding to the distraction length(mm)of 5,4,3,2,1 and 0 respectively,meeting the trans-sutural distraction osteogenesis requirements in skull of 5-week-old SD rats.The distractor was plased into the sagittal suture of 12 SD rats.Continuous sampling was conducted 1,3,5 and 7 days respectively(n=3)after operation.The tissue changes in the trans-sutural distraction area were observed by HE and Masson's trichrome staining.Inflammation levels were determined using Arg-1 immunofluorescence staining.The early angiogenesis was clarified through co-staining with CD31 and EMCN.Results:A stable trans-sutural distraction osteogenesis model was estab-lished,5 mm distraction osteogenesis width was observed completely within 7 days of distraction.Significant new bone formation was observed at 7 days after operation.Arg-1 expression increased and was concentrated at the bone margins,overlapping with the areas of new bone formation.EMCN expression gradually decreased,and by day 7 CD31 was predominant,indicating the basic maturation of blood vessels.Conclusion:This study successfully constructed a stable and effective trans-sutural distraction osteogenesis animal model,and provides an experimental basis for the investigation of its early continuous histological changes.