Although there is strong evidence that bisphosphonates prevent certain types of osteoporotic fractures, there are concerns that they may be associated with rare atypical femoral fractures.

1480 patients of proximal femur and shaft fractures over a period of 2 years from Jan 2014 to Jan 2016 were retrospectively reviewed in Gloucestershire Hospitals NHS trust. Hospital trauma database was used.195 patients had fractures in subtrochancteric and femoral shaft area.

11 patients had atypical femur fractures as defined by American society for bone and mineral research (ASBMR) task force 2013, revised criteria. Ten were female, one was male. Patients were aged from 68 to 97. In 6 patients, fractures were in the shaft, 5 in subtrochancteric area and 4 patients out of these had bilateral fractures. 10 out of 11 patients were on bisphosphonates. 4 patients had delayed diagnosis. 5 out of 11 patients did not have contralateral femoral x-rays. Treatment, 9 patients had intramedullary nail, one blade plate, and one treated conservatively. One patient in the IM group, had bilateral nailing. Average follow up was 7.6 months (range 1 to 16 months). At the end of the study, only 4 had united, 6 had not united and one not followed up. 4 out of 7 had low Vitamin D levels, 3 out of 7 had their bisphosphonate treatment stopped and 2 had histology which showed necrotic bone with trabeculae surrounded by fibrosis.

Increasing number of patients are on bisphosphonates for osteoporosis. Atypical femur fractures from bisphosphonates are often occult, often bilateral, with delayed healing. Patients on bisphosphonatetreatment should be advised to report any thigh or groin pain. Painful incomplete fractures need treatment with cephalomedullary nailing. Bone biology needs correcting by stopping bisphosphonatesand administering calcium & vitamin D supplements.

Implications: We need to raise awareness amongst treating clinicians and have national guidelines.