THE USE OF OSTEOGENIC PROTEIN-1 (MBP-7) IN THE TREATMENT OF RECALCITRANT LONG BONE NON-UNION

Abstract

Aim: To review the efficacy of Osteogenic Protein-1 (OP-1; BMP-7) in treating non-unions of fractures of the long bones.

Method: Twenty-eight patients who had previously had non-unions of long bone fractures treated unsuccessfully by conventional methods were entered into the study. OP-1 was used with autograft in 22 cases (OP-1 Implant is composed of 3.5mg OP-1/1g bovine bone collagen). The author reviewed all x-rays and, with the assistance of the 21 treating surgeons, assessed the clinical outcomes.

Results: There had been an average of 3.1 (median = two, range: one to 12) previous procedures and 24.3 months (median = 22 months, range: five to 84 months) since the injury. Twenty of the non-unions were diaphyseal and eight were metaphyseal. Seventeen of the 28 patients had some alteration to internal fixation. Nine patients had significant concomitant conditions. On clinical examination, 20 fractures had united, three were unable to be assessed and five had failed. The average time to union was 5.6 months (range: three to 15 months). When the x-rays were reviewed 21 had united. Two were unable to be assessed and five had failed. There were no adverse events or complications that can be attributed to the use of OP-1.

Discussion: This is a follow up of 28 difficult cases which had failed to respond to the current gold standard for treating recalcitrant non-unions. The contribution made by alteration of fixation needs to be recognised. Irrespective of this fact, there had been an average of 3.1 previous bony procedures involving grafting and changes of fixation.

Conclusion: OP-1 initiates bone formation in humans, it appears to be safe and may potentiate the action of autograft. The results for this group of recalcitrant cases suggested that it had been useful in obtaining successful outcomes for these patients who had failed to unite their fractures after traditional techniques had been used.