Guided bone regeneration using a bone tissue engineering complex consisting of a poly-dl-lactide membrane and bone mesenchymal stem cells

Developmental dysplasia of the hip (DDH) is one of the most common diseases encountered in pediatric orthopedic departments. Current treatment strategies seek to improve acetabular coverage, the principal defect of acetabular dysplasia, but are not very successful. We developed a guided bone regeneration (GBR) strategy to improve acetabular coverage via bone tissue engineering (BTE). Poly-dl-lactide (PDLLA) membranes were seeded with bone marrow mesenchymal stem cells (BMSCs) to form a BTE complex, which was then implanted into the superior margin of the acetabulum in a rabbit DDH model. Twelve weeks later, a small amount of high-density shadowing was evident on X-rays of the superior margin of the acetabulum, specimens of which exhibited new bone formation. Micro-computed tomography yielding three-dimensional images revealed that new bone had formed in the superior acetabulum, the basal part of which had fused with (and thus reconstructed) the autogenous bone, and new trabecular bone featuring transverse interlacing was evident in the interior of the hip. No clear evidence of bone formation was observed in rabbits that underwent sham operations or that were implanted with PDLLA only. Thus, it may be possible to improve acetabular coverage via BTE-based bone regeneration.