In times of plentiful nutrition an environmental advantage turns into a problem - obesity. Apart from an increase in morbidity and overall mortality the development of osteoarthrosis is well documented. Pre-arthrotic conditions may arise from trauma and can lead, depending on the pattern of injury, to full-blown arthrosis. The presence of obesity can play the role of a relevant progressive factor in this setting. Here we report about the case of an obese man (BMI 53.5 kg/m(2)), who suffered a fracture of the femoral head with acetabular participation (Pipkin IV) as well as a fracture of the tibial plateau. Operative management and rehabilitation were followed by gastric bypass surgery for weight reduction. The case is discussed with regard to the present literature.