The authors present their experience using osteogenic protein 1 (OP-1; “Osigraft”) in the treatment of recalcitrant atrophic pseudoarthrosis (PA) of the limbs in patients in whom osteosynthesis surgery failed at least two to four, and more, times. All patients with PA who were treated showed a preoperative radiographic pattern of severe bone atrophy surrounding the peri-fracture zone, without evident signs of reparative activity. All osteosynthesis hardware showed clear evidence of mechanical failure (rupture or mobilisation) so they were changed in all patients during the surgery. From January 2003 to February 2004 we used Osigraft to treat 10 patients with an atrophic PA at the following level: two femurs, three humera, one forearm, three tibiae (1/4 distal) and one tibia (1/3 medium). Osigraft was associated in seven patients with an autograft and in three patients with an allograft plus platelet growth factors (one distal femur, one distal tibia and one humerus). Mean age of patients was 38 years (range: 22–54) and mean duration of disease from the initial trauma was 36 months (range 26–40).

The radiological aspect of the newly formed bone, both endostal and periostal, was very similar to that observed in primary healing, with an inter-fragmentary callus as observed in similar cases treated since the beginning with the most appropriate therapy and that healed after the first operation. In all cases we observed healing of the PA focus in a time period of 6–11 months (mean 8.5) with a satisfactory functional recovery in eight cases; in two cases residual articular stiffness, one knee and one ankle, will require arthroscopic surgery.

Because of the limited number of patients treated with this new method, we can only draw preliminary conclusions. However, compared with our previous experience, we can confirm that Osigraft (OP-1) significantly contributes to bone healing whenever biological reparative potential is strongly compromised because of the type of original trauma, the long time elapsed since then and the many preceding surgeries. Healing times, even if they appear to be quite long, are actually short considering the severity of our cases, usually requiring further surgery for PA not healing after the third intervention (more than 30 %) and cured, if reached, in 12–18 months.