Abstract
We present results obtained in patients treated in Italy with BMP7/OP-1, Eptotermin alpha) carried by type 1 collagen (Osigraft) in an observational, prospective, multicentre, non-randomised study. OP-1/collagen is the first human recombinant BMP/OP approved for clinical use in tibial non-union refractory to autograft (Europe) or in long-bone non-unions (US, Australia and Canada). A prospective, randomised, controlled clinical study demonstrated that OP-1 has clinical and radiographic efficacy in tibial non-union comparable to autograft, with better tolerability. Non-randomised trials have shown a high clinical efficacy of OP-1 in complex recalcitrant long-bone non-unions as well.
Data on some of the patients treated in Italy with OP-1 from June 2002 –to December 2003 have been collected; we evaluated the data from 45 patients (18 surgeons) with a diagnosis of long-bone non-union (69%, in 81% atrophic/oligotrophic), delayed union (18%) or bone defect/cyst (7%). The mean age was 43±17 years (range 5–76 years) and the mean number of previous surgeries was 2.3±2.3 (range 0–13), with a disease duration from the original trauma of 18.9±20 months (range 1–93 months). Of the patients, 25% had previously received an autograft. In some patients (34%) complications were present (osteomyelitis, infections etc); in 53.3% of cases OP-1 was mixed with other agents (including 31% association with iliac crest autograft).
Radiographic analysis at 9 months (in PA patients only) has shown that Osigraft is efficacious in 78.6% of patients (67.9% union and 3.7% marked bone bridges); radiographic unions were reported in 34.8% at 4–5 months and in 60% at 6–8 months. In Osigraft-only treated patients, radiographic union at 9 months was 82.4% (plus 3.6 % marked bone bridges). Treatment failure was reported in eight of 45 patients (19.5%), including four cases in which Osigraft was mixed with iliac crest autograft; in four patients mechanical stability was insufficient,in three postoperative osteomyelitis developed and in one a silent osteomyelitis was present and considered the cause of the failure. No adverse events (AE) were reported.
Even if this study has limitations because it is observational, not randomised and no protocol was applied, as all naturalistic studies, it give us information about current clinical practice. The radiographic results observed were comparable with those reported in the literature in randomised and non-clinical series, indicating an efficacy of Osigraft close to 80 %, expecially in cases where the drug was used without autograft. The complete absence of AE is also relevant. The analysis of the failures reaffirm some basic principles that have to be respected such as mechanical stability, bone continuity and contact with vital/non-infected bone tissue.
