Atypical Subtrochanteric and Diaphyseal Femoral Fractures Associated with Long-term Bisphosphonate use in Postmenopausal Osteoporosis – A Case Study
Category: Osteoporosis - Treatment (Clinical)
Poster Sessions, Presentation Number: MO0365
Session: Poster Session III and Poster Tours
Monday, October 15, 2012 11:30 AM - 1:30 PM, Minneapolis Convention Center, Discovery Hall-Hall B
* Oliver Bock, Charité - Campus Benjamin Franklin, GERMANY, Uta Stege, Charité - Campus Benjamin Franklin, Germany, Dieter Felsenberg, Charité - Campus Benjamin Franklin, GERMANY
Objectives: The incidence of atypical femoral fractures (AFF) associated with the use of bisphosphonates (BP) for the treatment of patients with osteoporosis appears to be very low. Moreover, a causal association between BP and AFFs has not been clearly established. However, recent observations suggest that the risk rises with increasing BP exposure, and there is concern that lack of awareness and underreporting may mask the true incidence of the problem. Despite their relative rarity, AFF, if occurring in individual patients, are of great challenge for further medical management.
Patients and methods: We report here on five patients with altogether eight BP-associated AFF who were identified in or referred to our osteoporosis outpatient clinic since November 2009. This case study follows the recommendations given by the ASBMR for AFF reports. We provide detailed information on individual risk patterns and treatment considerations as well as on different therapeutic outcomes.
Results: All five AFF patients in our case study were treated with BP for postmenopausal osteoporosis (including one case with primary hyperparathyroidism occurring later during BP treatment). Their mean age at the time of (first) AFF was 75 years (range: 66-86 years), the mean duration of BP treatment was 7 years (range: 3-11 years). Two patients suffered from bilateral, complete subtrochanteric AFF followed by delayed healing after osteosynthesis – both these patients had a medical history with long lasting rheumatoid arthritis, glucocorticoid and proton-pump inhibitor treatment. The other four AFF occurred in three patients without any additional clinical risk factors recently discussed in the pathogenesis of AFF and showed the radiological patterns of incomplete diaphyseal insufficiency fractures with involvement of the lateral cortex only. Otherwise, our patients with complete or incomplete AFF and with subtrochanteric or diaphyseal AFF, respectively, did not differ in prior fracture, BMD and BTM history.
As for the moment of abstract submission, one out of three patients treated with teriparatide showed after two years clinical and radiographic evidence for improved fracture healing. On the other hand, in a case with assumed contraindications for teriparatide one complete diaphyseal AFF developed from an originally incomplete insufficiency fracture.
* Presenting Authors(s): Oliver Bock, Charité - Campus Benjamin Franklin, GERMANY