A retrospective analysis of bilateral fractures over sixteen years: localisation and variation in treatment of second hip fractures.

The aim of this study was the evaluation of contralateral hip fractures after a previous hip fracture. For this retrospective analysis patients were selected from the database of the LUMC, a teaching hospital in the south-west of the Netherlands. We analyzed all patients with a second fracture of a hip between 1992 and 2007. The exclusion criteria were high impact trauma and patients with diseases or medication known to have a negative effect on bone metabolism. A total of 1,604 hip fractures were identified. The possible predictive factors for the second fracture and descriptive statistics related to surgery (Hb and HT before and after the operation, total amount of intra- and postoperative blood loss, type of osteosynthesis, complications, time of death after the last fracture, time between arrival in the hospital and operation and hospital stay for both fractures) were recorded. A total of 32 second hip fractures were identified (2%) at a mean of 27.5 (SD 28.9) months after the initial hip fracture. The mean age at the first fracture was 77.2 years (SD 11.7), and 27 of 32 patients were female. Of these 32 patients (64 bilateral hip fractures), 32 fractures were intracapsular (1 femoral neck, 31 subcapital) and 32 were extracapsular fractures (6 subtrochanteric, 26 transtrochanteric). Although 24 of the 32 patients had identical first and second hip fractures, only eight out of 32 hips were treated with the same implants. There was a significant difference in Singh index between both hips at the time of the first fracture. There was also a significant difference in Singh index between the hip which was not fractured compared with its subsequent index when it was broken. All other studied patient and fracture characteristics were not significantly different. In this population the percentage of second hip fractures was relatively low compared to other studies. The choice of implants in this study shows that implants were chosen randomly. Because there is a significant difference in the Singh index during first and second hip fracture, osteoporosis medication might help reduce the incidence of second hip fractures.