[Sex and age associated to femur and rotula fractures]. / Fracturas del fémur y rodilla. Asociación con edad y sexo.

OBJECTIVE: To identify specific fractures risks of the following bones: distal femur, patella and tibia plateau, according to sex and age, with special interest in women >or= 50 y.o. MATERIAL AND METHODS: An epidemiologic case-control study was done between January 2002 and December 2005. The incidence rate for fractures were got by year, sex and age. The group exposed to the risk factors, was represented by female patients >or=50 y.o. The cases with fracture's worst prognosis were: distal femur (supracondylar, supraintercondylar or condylar), tibial plateau (Schatzker IV-VI); the control group was made with patients which fractures were in: proximal femur (Subtrocantheric, diaphysis), tibial plateau (Schatzker I-III). Descriptive and inferential analysis were done separately and together. RESULTS: 1578 Patients were studied. Incidence of fractures in the studied regions was of 5.9 per 10 000 persons/year (py), being of 5.7 and 4.9 per 10,000 py for men and women, respectively (p < 0.001). In subjects with age >or=50 y.o. the incidence rate was of 10.5 and 6.6 per 10 000 py for men and women, respectively. In the study patients less than 50 y.o. the incidence rate was of 1.6 per 10 000 py for both sexes (p < 0.001). The women >or=50 y.o. presented an OR of 5.1 (95% CI: 2.7-9.8, p < 0.001). CONCLUSIONS: In this study sample, the risk of fracture of the femur and the knee was greater in men than in women. In the >or= 50 y.o. age group, the ratio was inverted, with special interest in distal femur fractures. According to sex and age, no differences were identified in tibia plateau fractures.