Osteoporosis Management in a Patient with Osteogenesis Imperfecta with Atypical Femoral Fracture after Chronic Bisphosphonates Use

Program: Abstracts - Orals, Poster Previews, and Posters
Session: FRI 368-390-Metabolic Bone Disease Case Reports (posters)
Clinical
Friday, April 1, 2016: 1:15 PM-3:15 PM
Exhibit/Poster Hall (BCEC)

Poster Board FRI 373
Jing Yuan Tan*1 and Cherng Jye Seow2
1National University of Singapore, 2Tan Tock Seng Hospital, Singapore, Singapore
Background:

We report a case of a patient with osteogenesis imperfecta (OI) and an atypical femoral fracture (AFF) secondary to chronic bisphsophonate use who was successfully treated with teriparatide. 

Case presentation: 

A 63 year old man with OI and osteoporosis was treated with bisphosphonates for 9 years. He subsequently suffered a spontaneous atypical femoral fracture (AFF) in the form of a new transverse fracture over the subtrochanteric region of the right proximal femur. Oral alendronate was discontinued and he was started on teriparatide 20 microgram per day. A dual X-ray absorptiometry (DXA) scan performed just prior to teriparatide therapy showed a lumbar spine bone mineral density (BMD) of 0.715g/cm2 and T-score of -2.5. BMD of the total hip was 0.584g/cm2 and T-score -3.7. After one year of treatment with teriparatide, the patient experienced a substantial improvement of 9.8% in BMD in the lumbar spine (BMD 0.785g/cm2 and T-score -1.9) and 15.7% in the hip (BMD 0.676g/cm2 and T-score -3.0). No new fractures were reported in the one year of treatment.

Discussion 

Recent studies and case reports have alluded to the beneficial effects of teriparatide in the treatment of osteoporosis in patients with OI. Teriparatide is a parathyroid hormone analog that stimulates chondrocyte proliferation and differentiation as well as cartilage production. It also increases bone density by stimulating proliferation of osteoblastic progenitor cells, production of bone matrix proteins and osteoclastogenesis. While bisphosphonates are the first line treatment for osteoporosis, prolonged usage may result in AFF, as was seen in our patient. Switching to teriparatide showed significant improvement in BMD over a short period of time. In OI, there is impairment of bone matrix synthesis with resultant osteoblastic dysfunction and remodeling abnormalities. Our results indicate that anabolic therapy is capable of increasing bone formation and bone mass in this group of patients.

Conclusion: 

Teriparatide is a useful treatment for osteoporosis in patients with OI. However, its usage is limited to a maximum of 2 years. Risk of new fractures due to OI and osteoporosis remains high but unfortunately, there is no consensus as to which osteoporosis medication to continue subsequently.

Holm, J., Eiken, P., Hyldstrup, L.., Jensen, J. Atypical Femoral Fracture in an Osteogenesis Imperfecta patient successfully treated with teriparatide. Endocr Pract. 2014;20(No.10)

Nothing to Disclose: JYT, CJS

*Please take note of The Endocrine Society's News Embargo Policy at https://www.endocrine.org/news-room/endo-annual-meeting/pr-resources-for-endo