The purpose of this study was to determine the natural history of @entity77 pellets implanted during @entity174 surgery. The study group consisted of @entity1 sustaining an @entity174 with intraarticular comminution or marginal impaction or both in whom @entity77 pellets were implanted in lieu of autologous bone graft. Between 1997 and 1999, 32 @entity174 were treated. Followup adequate to delineate pellet outcome, including radiographs and computed tomography, was obtained in 31 @entity1 . Evaluation of plain radiographs showed that the @entity77 pellets became undifferentiated from the surrounding bone at an average of 7 weeks postoperatively. In no case was a residual bony deficit seen. Computed tomography analysis showed that in 22 @entity1 , the pellets essentially had been (> 90%) replaced by bone and in four @entity1 , the majority (> 50%-90%) of the pellets had been replaced by bone. However, in five @entity1 , less than 50% of the pellets had been replaced by bone, including one showing no bony replacement. The common finding in @entity1 with an extensive residual deficit was direct communication of the pellets with the joint space shown on the postoperative computed tomography scan. @entity1 with the best results had complete containment of the pellets within bone. Therefore, it seems that implanted @entity77 pellets in contact with joint synovial fluid are at risk for resorption without significant bony response. If @entity77 pellets are to be implanted in a periarticular location, complete bony containment is desirable. Evaluation of the periacetabular bony response requires computed tomography scans, as plain radiographs are inadequate for this purpose.

@entity77 used as bone graft substitute in XXXX fixation.

@entity1 :: ('9606', 'Species') :: ['Patients', 'patients'] @entity77 :: ('MESH:D002133', 'Chemical') :: ['calcium sulfate'] @entity174 :: ('MESH:D050723', 'Disease') :: ['fractures', 'acetabular fracture']
@entity174 :: (MESH:D050723,Disease) :: ['acetabular fracture']
