Background
Acetabular bone stock loss is a major problem in both primary and revision total hip arthroplasty (THA). The loosening of primary cemented and cementless components of THAs is also accompanied by a loss of bone stock. There are several options for reconstruction of the acetabular defects. In 1979, a biologic method was introduced with tightly impacted cancellous allografts in combination with a cemented polyethylene cup for acetabular reconstruction, to restore acetabular bone stock, to restore normal hip biomechanics, and to allow for further revision if needed.
Aim of the work
In this study, the results of using morcellized impacted bone graft to reconstruct the deficient acetabulum in 54 hips (49 patients) using either cemented or cementless cups are discussed, with a mean follow-up of 36 (6–96) months.
Patients and methods
Between May 2002 and April 2010, 54 hips (in 49 patients) with deficient bone stock on the acetabular side had undergone total replacement with acetabular reconstruction using morcellized bone impaction grafting; out of the 54 hips, 34 (63%) were primary THA (17 after fracture of the acetabulum, 12 for protrusio acetabuli, three for rheumatoid arthritis, one for dysplastic hip, and one after tuberculosis arthritis) and 20 hips (37%) were revision THA. There were 21 (43%) women (bilateral in three of them) and 28 (57%) men (bilateral in two of them). Average age was 53 years (range 26–98 years). Out of the 54 hips, 14 (26%) were cementless and 40 (74%) were cemented. Mesh was used in 27 (50%) hips to convert a noncontained defect into a contained defect. Octopus ring was used in one hip, and Muller ring was used in another hip to overcome pelvic discontinuity.
Results
Fifty-four hips in 49 patients were followed up clinically and radiologically, with a mean follow-up of 36 months. In 46 hips (95.8%), the graft showed radiological signs of union to the host bone and no cup loosening. Cup was loose and revised in two patients (4.2%). One patient had octopus ring and morcellized graft in the first operation, and it was revised using a mesh and morcellized graft 8 years later. The other patient had morcellized graft and Muller ring; this failed after 4 years with cup loosening. It was revised using mesh and morcellized graft.
Conclusion
Acetabular reconstruction is a demanding procedure and needs preoperative planning and armamentarium. Successful results were obtained using the impaction technique for reconstruction. The aim of bone graft is to restore the normal hip mechanics. The union rate of the impacted graft is relatively satisfactory compared with other grafting methods. Augmentation of the grafting technique by mesh or rings added more stability to the cup component. The use of impaction graft in revisions for infected hip did not increase the risk of reinfection.