Sample Size There is not much information prior to this study. It has been assumed that the mean differences for the changes in FEV1.0, FVC and pains score at 5 days after surgery between bone cement and control groups to be 15% and the standard deviation to be 25% respectively. With these assumptions, a two-sided test, overall level of significance at 5% and power of 80%, the number of patients that is needed to be enrolled in this study is 64 patients per group after accounting that there will be 1% chance that the patient may have some major postoperative complication that will prevent the patient from being extubated at 5 days after surgery. The total number of patients that need to be recruited in this study is 128 patients.