Treatment of fracture non-union with tissue-engineered bone grafts

When pseudoarthrosis occurs due to poor union of a bone fracture, cancellous bone with high cellular activity is generally harvested from the ilium and then grafted to the affected area to facilitate bone union. However, graft harvest is associated with frequent complications and pain. If a tissue engineering approach was available, bone defects could be repaired without damaging normal tissues. Subjects were 13 graft patients with pseudoarthrosis (average age, 56.9 years; range, 17-82 years). Pseudoarthrosis affected the thoracolumbar spine, the femur, the clavicle, and the metatarsal bone. From the ilium (tibia in one patient), 10-20 mL of bone marrow fluid was collected, and then, it was cultured in the standard medium containing minimum essenttial medium (MEM). After 2 weeks in primary culture, cells were subsequently incubated with porous beta-tricalcium phosphste (TCP) in order to prepare tissueengineered bone, according to the previously reported modified culturing technique. Tissueengineered bone (TEB) was grafted around the non-union site of each affected bone. In all patients, X-ray and CT showed good bone formationat three months after surgery. The TEB graft underwent remodeling and bone union was confirmed. In 3 patients, bone biopsy was performed during removal of internal fixation and bone regeneration was confirmed histologically. This tissue-engineered artificial bone provides a graft with a high regenerative capacity that can be prepared by minimally invasive aspiration. Compared with iliac bone grafts, it is possible to markedly reduce postoperative pain and the loss of autogenous bone.