A tissue engineering strategy for the treatment of avascular necrosis of the femoral head.
BACKGROUND & PURPOSE
Skeletal stem cells (SSCs) and impaction bone grafting (IBG) can be combined to produce a mechanically stable living bone composite. This novel strategy has been translated to the treatment of avascular necrosis of the femoral head. Surgical technique, clinical follow-up and retrieval analysis data of this translational case series is presented.


METHODS
SSCs and milled allograft were impacted into necrotic bone in five femoral heads of four patients. Cell viability was confirmed by parallel in vitro culture of the cell-graft constructs. Patient follow-up was by serial clinical and radiological examination. Tissue engineered bone was retrieved from two retrieved femoral heads and was analysed by histology, microcomputed tomography (μCT) and mechanical testing.


RESULTS
Three patients remain asymptomatic at 22- to 44-month follow-up. One patient (both hips) required total hip replacement due to widespread residual necrosis. Retrieved tissue engineered bone demonstrated a mature trabecular micro-architecture histologically and on μCT. Bone density and axial compression strength were comparable to trabecular bone.


CONCLUSIONS
Clinical follow-up shows this to be an effective new treatment for focal early stage avascular necrosis of the femoral head. Unique retrieval analysis of clinically translated tissue engineered bone has demonstrated regeneration of tissue that is both structurally and functionally analogous to normal trabecular bone.
['Aarvold|A|A|', 'Smith|J O|JO|', 'Tayton|E R|ER|', 'Jones|A M H|AM|', 'Dawson|J I|JI|', 'Lanham|S|S|', 'Briscoe|A|A|', 'Dunlop|D G|DG|', 'Oreffo|R O C|RO|']
D000328:Adult D064591:Allografts D016025:Bone Transplantation D005260:Female D005271:Femur Head Necrosis D006801:Humans D008297:Male D017410:Practice Guidelines as Topic D033581:Stem Cell Transplantation D023822:Tissue Engineering D016896:Treatment Outcome
Avascular necrosis Femoral head Skeletal stem cells Impaction bone grafting Translation