This research is aimed to evaluate the combination of mesenchymal stem cell, HA-CaSO4, BMP-2, and implant in treating critical-sized bone defect.

In the presence of critical-sized bone defect whose defect size is more than 2.5 cm, bone will suffer a healing disturbance. In treating these conditions, the conventional method were vascularised bone grafting and bone transport. But the existing methods of treatment have many weaknesses Vascularized bone graft is a procedure with a high level of difficulty. Hence not every orthopaedic surgeon were able to perform it. It also takes more operating time and its failure rate is also quite high.

Meanwhile, external fixation which is applied with bone transport, was being often complained by the patient in terms of cosmetic and psychologically.

According to diamond concept of bone healing, there are four main factors that influence the bone healing. These factors are osteogenic factor (mesenchymal stem cell), osteconductive factor (HA-CaSO4), osteoinductive factor (bone morphogenetic protein-2) and mechanical component (implant). The potency of each component in fracture healing with/out bone defect has been proved in many studies. The combined effect of these components is often studied as well, but not in critical-sized bone defect.

Inclusion Criteria:

• subjects with critical size defect of bone

Exclusion Criteria:

• subjects with patological fracture caused by primary or secondary bone malignancy, imunological deficit, active hepatitis or those who's under immunosuppresant therapy or other therapeutic modality that can interferes with bone healing.