In Order to evaluate to the risk factors of hip fracture, we reviewed 34 patients, who were over 70 years old, from Jan. 1991 to Dec. 1993.

The patients who have preexisting desease such as chronic illness, or in case of traffic accident, and fall down injury were excluded.

We measured the singhs index and femoral neck-shaft angle on simple X-ray, bone mineral density for quantitative measurement of mineral on dual photon absorptiometry, and calcium, phosphate, and alkaline phosphatase on serologic study.

We compared the results with control group who have not orthopaedic problems in 20 old aged person, and the results obtained were as follows.

1. The male to female ratio is 11:23, a high rate in female, and the mean age of patients is 74.3 years old, ragne from 70 to 89 years.

2. Femoral neck-shaft angle of patient group is 141.67±5.3 compared to 143.40±4.8 of control, showed statistical significance.

3. Bony trabeculae index of proximal femur of patient group is 1.83±0.83 compared to 2.91 ± 0.86 of control, showed statistical significance.

4. In patient group, about 30% decreased in bone mineral density compared control. This result must be requisite to reinvestigation and statlstical analysis were not carried due to numbers of members of control.

5. There is no significant difference between two groups regard to serologic study.

In summary, risk factors of hip fractures are aged female with decreased femoral neck-shaft angle, below third degree in singhs index and lower bone mineral density compared with same age.

According to the our data, in case of hip fractures in old aged, for prevent the postoperative complication and refracture, prophylactic theraphy to collectible causes are required, in addllion to operative internal fixation.