Technical factors affecting cup stability in bone impaction grafting

Favourable long-term clinical results can be achieved by the bone impaction technique in bone stock deficient acetabuli. Originally, firm impaction of manually prepared bone grafts using a rongeur was performed. An alternative technique for producing bone grafts is reaming from the pelvic wall or femoral head, which produces smaller-sized slurry bone grafts. These slurry grafts can be manually compressed in the bone defect using an acetabular reamer en reverse. In an artificial acetabular cavitary defect model both reconstruction techniques were compared in combination with a cemented cup. Mechanical testing was performed with a sequentially increasing dynamic load. Roentgen stereophotogrammetric analysis was used to determine initial cup stability. At all testing levels the initial stability of the cups reconstructed with slurry grafts and reversed reaming was significantly less in comparison to the original impaction technique. The original technique with firm impaction with a hammer and impactors of relatively large-sized bone grafts provides optimal initial stability. The reversed reaming technique of slurry grafts cannot be recommended for bone grafting of acetabular defects.