The Cumulated Ambulation Score (CAS) (4) is a tool developed and tested for initial predicting the in-patient length of stay following a hip surgery. The CAS consists of documenting the patient's ability and independence while performing 3 basic daily activities (sit to stand, transfer out of bed and mobilization). It is calculated using a score of 0-2 for each parameter, giving a total daily score of 0 to 6 and a score of 0 to 18 during the first 3 post-operative days. The CAS is then the sum of scores of the first 3 post-operative days. This score proves to be an effective tool for predicting the length of stay, and other parameters investigated such as survival rate and return home after a proximal femoral surgery.