Impacted Bone and Calcium Phosphate Cement for Repair of Femoral Head Defects

Abstract

Bone impaction grafting has been advocated for reconstruction of femoral head osteonecrosis. However, bone grafts do not prevent the progression of collapse and subsequent disabling osteoarthritis in late-stage osteonecrosis. We hypothesized reconstruction of large subchondral defects with a mix of impacted morsellized cancellous bone grafts and calcium phosphate cement would afford mechanical stability allowing remodeling into new bone without femoral head collapse. In a pilot study we created a critically sized subchondral defect model in 15 goats following the trapdoor procedure. Defects were left empty (n = 3), filled with morsellized cancellous bone grafts (n = 6), or filled with a mixture of morsellized cancellous bone and calcium phosphate cement (n = 6). No defects collapsed by sacrifice at 12 weeks. Defects filled with morsellized cancellous bone showed complete incorporation and remodeling to a normal trabecular structure. In the morsellized cancellous bone/calcium phosphate cement group, most of the calcium phosphate cement was resorbed in 12 weeks and the mixture was largely replaced by fibrous or fatty marrow. Although the specific mixture did not confirm our hypothesis, we suspect a slower resorbing calcium phosphate cement remains a promising material to mix with morsellized cancellous bone to treat late stages of femoral head osteonecrosis.

An overview on bone manifestations in Gaucher disease

“…Mattsson and Larsson [94] found in 40 patients with femoral head neck fractures that internal screw fixation in combination with an additional augmentation with calcium phosphate cement proved to be beneficial for stability. In a pilot study [95] performed in goats critically sized femoral head defects were filled with either morsellized cancellous bone alone or with a mixture of calcium phosphate cement showing no themenschwerpunkt wmw 23-24/2010 Ó Springer-Verlag Mikosch and Hughes -Gaucher disease and bone collapsed defects. Thus, Ng et al [96] recently hypothesized that additional calcium phosphate cement, which is already widely used in stabilization of fractures, in conjunction with standard decompression of the osteonecrotic femoral head may prevent joint collapse.…”

Injectable synthetic bone graft substitute combined with core decompression in the treatment of advanced osteonecrosis of the femoral head: A 5-year follow-up

“…[20] But in the pilot study of Rijnen et al that compared incorporation and remodeling with or without the addition of CaPO 4 cement to morsellized cancellous bone using a femoral head critically sized defect model in the goat, inferior results were obtained in the group in which CaPO 4 cement was added. [25] After core decompression, the grafting materials should provide adequate mechanical strength to prevent further collapse of the osteonecrotic femoral head. In this study, the synthetic graft substitutes had early resorption after implantation.…”

From mishap to model: The origins and utility of experimental autoimmune encephalomyelitis

“…[14] However, some concerns about their efficacy have been raised before in a small animal study of core decompression. [16] Although such substitutes have been successfully used for other indications, Yu et al, hypothesize that the osteonecrotic environment in the femoral head is unsuitable for the synthetic graft to repair the lesion. These findings have already resulted in a change of practice Chang Gung Memorial Hospital.…”