Published experimental data on BMP-7(OP-1), carried by collagen type 1 (Osigraft), related to reconstructive surgery attest that: it accelerates and improves the incorporation of strut allograft; the combination of OP-1 with auto or allograft results in an improvement of critical size defect healing from radiological, histological and mechanical perspective.

In human revision hip surgery, OP-1 has been used with morcellized allograft, proximal femoral allograft and bulk femoral head allograft for acetabular or femoral reconstruction: a faster and more evident new bone formation as well as a faster incorporation of grafts has been shown compared to what expected without OP-1 usage.

Even if OP-1 usage in hip surgery is not approved by regulatory agencies, because of lack of randomised clinical studies, we decided to use it in patients with serious acetabular defects (II/III GIR).

In our experience, we treated eight patients with OP1, in conjunction with allografts. Clinical, radiographic and densitometric analysis has been done at 3, 6 and 12 months.

Preliminary densitometric results show that the quantity and features of new formed bone are superimposable to natural bone.