RESUMO
Distraction osteogenesis [DO] is a surgical procedure used to generate large volumes of new bone for limb lengthening. In this animal experimental study, a 30% lengthening of the left tibia [mean distraction distance: 60.8 mm] was performed in ten adult male dogs by callus distraction after osteotomy and application of an Ilizarov fixator. Distraction was started on postoperative day seven with a distraction rate of 0.5 mm twice per day and carried out at a rate of 1.5 mm per day until the end of the study. Autologous bone marrow mesenchymal stem cells [BM-MSCs] and platelet-rich plasma [PRP] as the treatment group [n=5] or PRP alone [control group, n=5] were injected into the distracted callus at the middle and end of the distraction period. At the end of the consolidation period, the dogs were sacrificed after which computerized tomography [CT] and histomorphometric evaluations were performed. Radiographic evaluationsrevealed that the amount and quality of callus formations were significantly higher in the treatment group [P<0.05]. As measured by CT scan, the healing parametersin dogs of the treatment group were significantly greater [P<0.05]. New bone formation in the treatment group was significantly higher [P<0.05]. The present study showed that the transplantation of BM-MSCs positively affects early bony consolidation in DO. The use of MSCs might allow a shortened period of consolidation and therefore permit earlier device removal