Structural Bone-grafting With Uncemented Cup For Acetabular Deficiency And Reconstruction

Objective To introduce the structural bone-grafting in conjunction with an uncemented cup for reconstruction of the defected acetabula.Methods A retrospective study was done on 26 hips in 25 patients (female 14 and male 11; average age 56 years) with bone loss in acetabula treated by this procedure for acetabular reconstruction in revision surgery (16 cases) and primary arthroplasty (9 cases). According to the American Academy of Orthopaedic Surgeons (AAOS) grading system, bone deficiency of all cases are defined with segmental acetabular defects (AAOS I ). The acetabular cup was placed at the anatomical level of the primary acetabula , and bone grafts ,harvested from autogenously femoral head or freeze-drying allografts ,were required for bone loss in all patients. The coverage of thecementless acetabular cup by structural grafts was less than 50% in all cases.The clinical evaluations were conducted with modified Harris hip score , and radiological evaluations were made in preoperative and follow-up periods (average 5.2 years , range 1.2-7.4 years) for each patient.Results All grafts were seen to be incorporated with the host -bone , and no collapse or fracture was found . Minor resorptions were confirmed in two cases. No clinical evidence of loosening of acetabular component was found inall patients , but the radiolucent line around the cup appeared in one case post-operatively, without widening progressively in the later follow-up .The average modified Harris score improved from 50 at preoperation to 88 at the final review.Conclusions The treatment for the acetabular deficiency with structural bone-grafting in conjunction with an cementless cup is effective. Satisfactory results could be obtained with less than 50% coverage of the cup by grafts, and the acetabular bone stock can be restored effectively.