Abstract
Introduction: Impaction bone grafting is a very useful technique in the armament of a revision hip surgeon. Traditionally fresh frozen allograft has been used for this technique. However there are concerns about the transmission of viral proteins and prions through this form of allograft.As a result irradiated bone graft has been favoured in some centres. There is no long term series describing the results of impaction bone grafting using irradiated bone
Method: We describe a series of 58 cases of acetabular revision surgery done at the Avon Orthopaedic Centre between 1995 and 2001 and followed up over a period of 48–90 months. The preoperative bone defect was graded by the Paprosky classification. There were 10cases of type 1,15 type 2a, 5 type 2b, 7 type 2c, 14 type 3a and 7 type 3c.50 cases were operated by the two senior surgeons and 8 were senior trainees.All uncontained defects were first contained by using a mesh or cages. The bone graft used was freeze-dried femoral head allograft, which was milled and used without defatting. The cases were followed up clinically and radiologically.Case notes were reviewed to gain information about the primary prosthesis, and operative details as well as the cause of the revision. All the cases were the first revisions.
The radiological picture was evaluated for signs of incorporation, remodelling, loosening and migration of the cemented acetabular component. Clinical evaluation was from the last clinic visit and included the presence of pain, mobility status, range of movement and patient satisfaction. Revision was the end point of the study
Results: There were no cases which underwent loosening and all the cups were stable.1 case had recurrent dislocation and was revised.26 (44.8%) cases showed changes of incorporation, and 4 cases (6%)showed changes of remodelling.23 cases (39.6%) underwent femoral impaction grafting as well. Clinically the results were satisfactory with absence of pain in 38 cases (65%). Trochanteric pain was present in 3 cases.
Conclusion: The results suggested that the results of impaction bone grafting on the acetabular side using irradiated bone graft are comparable to those with fresh frozen allograft and significantly better than those on the femoral side. This could be attributed to the compressive forces acting across the acetabular side as against the predominantly shear forces acting on the femur. The low percentage of remodelling remains a concern and warrants further studies.
Theses abstracts were prepared by Professor Roger Lemaire. Correspondence should be addressed to EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
