CUSTOM TEMPORARY ANTIBIOTIC-LOADED CEMENT PROSTHESIS FOR 2-STAGE SEPTIC HIP REVISION ARTHROPLASTY

Purpose of the study During the excision period of a two-stage revisio n arthroplasty, the hip has a low function and an unacceptable leg len gth discrepancy. The goal of this study was to expose technical detail s in order to perform a simple articulated cement spacer which could b e implanted during this period to improve hip function, to authorize p artial weight bearing and to avoid leg length discrepancy. Material Th is method was applied in three two-stage procedures justified because of particular immunodeficiency conditions: a 43 years old man who had bone marrow allograft and immunosuppressive therapy because of leukemi a suffering of subacute septic hip arthritis; a 58 years old man suffe ring of diabetes and active C-hepatitis who had a septic loosening of a total hip arthroplasty (THA); a 76 years old woman suffering of diab etes who had a third septic loosening of THA. Method The prosthesis wa s made of antibiotic-impregnated cement according to organisms antibio tic resistance. The prosthetic junction between head and diaphysis was reinforced with a tibial plate. Prosthetic shape was identical to the one of femoral broaches inserted in the femur after prosthetic and ce ment removal. The broach size was chosen when mechanical stability in the femur was obtained, and avoided leg length discrepancy after trial s with cups. The tibial plate was bent in order to reinforce the junct ion with regard to the shape of the determined broach. Two doses of an tibiotic-impregnated cement were mixed and molded with hands, then the plate was incorporated at the appropriate location, finaly the broach was applied on this composite and cement in excess was removed before polymerisation. For prosthetic head, two options were available: to m old the cephalic zone of the cement at the patient acetabulum diameter with a soft aluminium cup previously molded in the acetabulum; to mol d the cement cephalic zone with a trial cup in order to obtain a 22 or 28 ball. For this last option, a third dose of antibiotic-impregnated cement was prepared and placed in the acetabulum, a trial femoral hea d was applied in it to mold the location for the 22 or 28 prosthetic h ead. Before insertion, a collar was applied on the stem to prevent mig ration. Active mobilization was encouraged, and partial weight-bearing authorized. Results The mean range of hip flexion during period was 6 0 degrees. The patients were discharged approximatively 12 days after the first stage. Two patients had effective painless partial weight-be aring. The second stage was performed six weeks later on the average. The second procedure was easier than the second stage of a conventiona l two-stage procedure because of: easy and low hemoragic dissection au thorized by the prosthesis; low difficulties with soft tissue tension as the prosthesis prevents leg length discrepancy; preservation of the articular space which prevents soft tissue sacrifice during the secon d stage. Conclusion This simple technique is effective to prevent comp lications related to the excision period of a two-stage hip revision a rthroplasty. Likewise, the economical aspect (short delay of hospitali sation, quick functional recovery) should be considered when compared with the excision period of a conventional two-stage procedure.