Quantification by energy dispersive x-ray spectroscopy of alendronate in the diseased jaw bone of patients with bisphosphonate-related jaw osteonecrosis.

OBJECTIVE

Recently, specific in vitro bisphosphonate concentrations have been established for reaching a toxic threshold that could result in the induction of bisphosphonate-related osteonecrosis of the jaw (BRONJ), but these data have not been validated in vivo. The purpose of this study was to quantify the concentration of bisphosphonates (BPs) in the diseased jaw bone of patients experiencing BRONJ.

STUDY DESIGN

We hypothesized that if the average natural nitrogen content of mammalian bone is known, the excess of nitrogen in the jaw bone of BRONJ patients is likely to reflect the concentration of amino-BP. To test our hypothesis, jaw bone specimens from patients with BRONJ were acquired after sequestrectomy and analyzed by energy-dispersive X-ray spectroscopy (EDS).

RESULTS

The EDS analysis of the bone demonstrated a highly linear correlation between increasing concentrations of BP and the increasing percentage of nitrogen measured at the bone surfaces (R(2) = .9851, P = .0149).

CONCLUSIONS

SEM/EDS can be a valuable tool for assessing BP concentration in jaw bone and provides important insight into BP pharmacokinetics and BRONJ.