DISCUSSION Of our series of 73 patients hospitalized for treatment of malleolar fractures in a tertiary hospital, 63% were male. toward This finding is in direct contrast with that found by Baptista et al. 11 of only 30.0% of male patients in a study conducted with patients operated at another hospital, with similar characteristics in the same city. As the latter was carried out from 1989 to 1993, we believe that part of this difference can be explained by the time span of 18 years between both studies. However, the predominance of male subjects affected by malleolar fractures has also been found in studies of Santin et al. 12 and Schwartsmann et al. 14 with 62.8% and 54.0% respectively. It should be remembered that these two papers have analyzed only Danis-Weber type B malleolarfractures.

It is noteworthy in this study the low mean age of patients, 27.5 years old, with 56.2% of them standing in the age group below 40 years. We believe that the high turnout of traffic accidents, particularly motorcycle accidents, as a cause of fracture contributed to this fact. Debieux et al., 10 reported a study made in 2001-2002 in which they studied the locomotor injuries due to motorcycle accidents in S?o Paulo city and found that 79% of patients were under 28 years old. Our finding contrasts with the mean age of 39.0, 48.7, 43.3 and 34.5 years old from the work of Santin et al., 12 Schwartsmann et al, 14 Baptista et al. 11 and Tucci Neto et al., 13 respectively. The profile of patients with malleolar fractures treated at a tertiary hospital is well characterized when we analyze trauma mechanisms involved in the genesis of the fracture.

We found 54.8% (39 ankles) fractures caused by traffic accidents, and 21.9% (16 ankles) from polytraumatized patients, rates much higher than all other studies in the national literature. Santin et al. 12 described only one fracture due to motorcycle accident (2.9% of the total) and Tucci Neto et al. 13 had no patient from traffic accident. There is no doubt that Danis-Weber type B fractures evaluated in these two studies are typically caused by torsional trauma, and a lower incidence of fractures due to high-energy trauma was expected. Nevertheless, only 15.4% of patients in the study of Baptista et al. 11 were due to car accidents, and the same, as already mentioned, was conducted with patients from another major tertiary hospital.

There is no reference in the work of Baptista et al. 11 of fractures resulting from motorcycle accidents, whereas in our study 26.0% of all fractures resulted from this type of trauma. We believe that the changes Anacetrapib that occurred in the transport system of S?o Paulo city over the 18 years separating the two studies, with the continuous increase in the number of circulating motorcycles, and consequently in the number of accidents involving motorcyclists, are responsible for this change in the etiological pattern. Debieux et al.