Atypical femur fractures - Patient characteristics and results of intramedullary nailing for a series of 21 patients.

Atypical femoral fractures have been associated with long term use of bisphosphonates. Our study plan was to report the outcome of treatment for a series of -patients with an atypical femoral fracture and to compare the characteristics of those patients with a proximal femoral fracture. 21 atypical fractures were identified over a seven year period and these were compared with those of 2.547 hip fracture patients treated over the same time period at a single centre. The mean age of patients with an atypical fracture was on average nine years less than that for the hip fracture patients (72 as against 81 years, p = 0.002). Four (19.0%) of the patients with atypical fracture had no injury associated with the fracture and nine (42.9%) patients had pain prior to presentation at hospital for a mean of 31 days. Patients with atypical fractures were more likely to be smokers (9/21(42.9%) versus 319/2547 (12.5%), p = 0.0001) and more likely to be on long term oral steroid therapy (8/21 (38.1%) versus 131/2547 (5.1%), p < 0.0001) in comparison to other hip fracture patients. All the atypical fractures were treated by intramedullary nailing and healed uneventfully apart from one fracture that developed non-union requiring revision nailing. Residual pain at one year from injury was more prevalent for patients with atypical fractures.