RESUMEN
Osteoinductive demineralized bone matrix results from bone demineralization and is attributed to matrix-associated bone morphogenetic proteins. The osteoinductive potential can vary with donor. Many bioassay methods are available to screen donors, each with its own interpretation, so performance of more than one may be of value. Furthermore, little is known about the relationship between bioassay results and clinical outcomes. A study designed to meaningfully explore these issues would require assay of a large number of donors as well as clinical utilization in a large patient population. A preliminary study was undertaken to gain initial perspective. Using demineralized bone matrix derived from one 33-year-old female donor, 2 methods of bioassay and a clinical case study were performed. The levels of bone morphogenetic proteins 2, 4, and 7 in lyophilized demineralized bone matrix powder were measured (19.65 +/- 0.30 ng/g, 2.49 +/- 0.19 ng/g, and 82.03 +/- 6.89 ng/g, respectively). Also, putty (Osteostim DBM Putty), prepared from powder, was intramuscularly implanted in athymic rats and de novo bone formation quantified (6.7% +/- 3.5% new bone formation with 49% +/- 17% of the implant area associated with new bone formation). The putty, in conjunction with internal fixation, was used in the revision of a medial malleolar nonunion of an obese, 76-year-old woman. Radiographic union with excellent graft incorporation was achieved by 12 weeks postoperatively, with maintenance of an acceptable clinical result during the 14-month follow-up period. These results are interpreted in the broader context of demineralized bone grafting, in general, and an outline for further study is presented.