Materials and methods

The study was a case-control study using a sex and age matched control group. The fractures were classified according to Evans and OTA/AO classifications. Operative treatment was performed using dynamic hip-screw or cephalomedullary nailing systems. All patients were followed for at least 3–4 months postoperatively. The following risk factors were assessed: fracture type, quality of reduction by blinded assessment using a visual analogue scale, tip-apex distance (TAD) according to Baumgaertner, lag-screw positioning and other relevant additional risk factors in terms of walking ability, osteoporosis, cardio-vascular disease, neurological disease, diabetes, obesity, alcohol consumption and smoking.