Bone Mineral Density responsse to long-term Bisphosphonate Therapy in Fibrous Dysplasia.: Case report

PARISI MS; OLIVERI BEATRIZ; C GÓMEZ ACOTTO; MAUTALEN C

journal of clinical densitometry

ELSEVIER

Año: 2001 vol. 4 p. 167 - 172

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:ES-AR;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Fi brous dysplasia of bone is a rare disease related to a genetic mutation in which bone f`ormation at osseous sites is altered. ln the last few years, bisphosphonates have become one of the choice drugs to treat this dis- ease. A 26-yr-old woman presented after 6 wk of spontaneous right leg pain owing to a ftssure fracture of the right femoral neck, She reported precocious puberty at the age of 2, with diagnosis of McCune-Albright syn- drome. Radioisotope bone scanning, radiographic, biochemical, and densitometric studies were performed. Treatment with bisphosphonates was started because bone turnover biochemical markers were abnormal. Oral olpadronate followed by iv pamidronate substantially decreased bone resorption. Bone mineral density (BMD} of total skeleton and subareas was assessed by dual X~ray absorptiometry (DXA) throughout the 5 yr of treat- ment; At the end of this period, BMD of the total skeleton had increased 6,2%, However, BMD of the areas most affected by librous dysplasia, the legs and pelvis, had increased l2,7 and l l%, respectively. Region of interest analysis of individual bones of the legs performed with the total skeleton sean revealed that BMD of the areas most affected by librous dysplasia was lower than that of the less affected contralateral bones. During the first 3 yr, treatment with bisphosphonates substantially increased BMD of the right femur and tibia (22 and 28%, respectively}. After that, values seemed to stabilize. DXA evaluation of the total skeleton and its subar- eas was useful to evaluate the efhcacy of bisphosphonate treatment, Moreover, the plateau observed in BMD values after 3 yr of trcatrnent suggests that treatment could have been discontinued when the densitometric values stabilized. Key Wards: Fibrous dysplasia; bone mineral density; bisphosphonates.