Abstract The purposes of the present research were (1) to analyse and characterize the hip fractures treated at Oulu University Hospital during a one-year period using the special forms of the Standardized Audit of Hip Fractures in Europe (SAHFE) and to evaluate their value for quality control, (2) to compare gamma nail (GN) and dynamic hip screw (DHS) fixation for the treatment of trochanteric hip fractures, focusing especially on the functional aspects, (3) to compare the short-term outcome of gamma nail (GN) and dynamic hip screw (DHS) fixation for the treatment of subtrochanteric hip fractures, and (4) to examine the rate and reliability of the classification of basicervical hip fractures and the outcome of the operative methods used for their treatment. Oulu University Hospital joined the Swedish Hip Fracture Project (Rikshöft), aimed at developing the quality control of hip fracture treatment, in 1989, and this later evolved into a project called the Standardized Audit of Hip Fractures in Europe (SAHFE), funded by the European Commission. Registration of hip fractures on the SAHFE forms was common practise in Oulu from 1st September 1997 until the end of December 2003. SAHFE data collection forms were used in all four studies belonging to this thesis. There were 238 hip fracture patients during the one-year period of registration at Oulu University Hospital. The intracapsular / extracapsular fracture rate (60/40) and the female/male rate (80/20) seemed to be similar to those reported in the recent Finnish Health Care Register data. The most frequent method for treating cervical fractures was Austin-Moore hemiarthroplasty (68%) and that for trochanteric and subtrochanteric fractures GN fixation (86%). The SAHFE forms proved to be easy to use and practicable for evaluating the quality of hip fracture treatment. In a matched-pair study the short-term outcomes of the treatment of trochanteric fractures (after 4 months) were slightly better in the DHS group than in the GN group with respect to walking ability and mortality. The difference in mortality was at least partly due to the higher number of complications requiring re-operations associated with GN fixation. In the treatment of subtrochanteric hip fractures, there were four intraoperative complications (9.3%) in the GN group but none in the DHS group. On the other hand, postoperative complications were more common in the DHS group (20% vs. 2%). It is significant that all these complications in the DHS group occurred in Seinsheimer type IIIA fractures. It is concluded that, despite the perioperative problems associated with gamma nailing, this technique may be preferable to DHS fixation for specific fracture types with medial cortical comminutation, such as Seinsheimer type IIIA. Altogether 108 of the 1624 hip fractures were initially classified by the surgeons as basicervical fractures, but after a careful second look only 30 fulfilled all the criteria. The definitive rate of basicervical fractures was thus 1.8%. Treatment of basicervical fractures as trochanteric fractures proved superior to their treatment as cervical fractures, resulting in lower re-operation rates. In conclusions; this thesis suggests that SAHFE forms are very useful for evaluating the quality of hip fracture treatment. Both GN fixation and DHS fixation are effective methods for the treatment of trochanteric hip fractures in elderly patients; in less comminuted fractures, the DHS method is the preferred method of treatment whereas GN fixation is alternative treatment for more comminuted fractures. GN fixation is preferable for the subtrochanteric fratures. Basicervical fractures shoud be regarded clinically as extracapsular fractures and managed in a similar manner to trochanteric fractures.