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inexpensive modular femoral component or the removed femoral implant, which is autoclaved.We use trials of the acetabular component to dictate the size of the acetabulum. On the femoralside, we use trials for spacer G (TECRES S.P.A.), of which only 3 sizes are available (Fig 1), todictate the size that best fits into the femoral canal diameter, which is equivalent to the plannedstem diameter together with its cement mantle.Fig.1Trials for spacer G (TECRES S.P.A.)After determining the size of acetabulum (eg 54mm), we use the acetabular reamer tray of thesame size (54mm) as a mold and a sterile sofratol sheet is used to line reamer tray, antibioticimpregnatedpolymethylmethacrylate is then mixed and applied in the doughy phase in the trayreamer which is lined with sofratol, and definite polyethylene liner (the smallest diameter thatmatches 28mm head) is inserted in the tray reamer till polymerization is completed to get invitrocemented polyethylene construct (Fig 2)Fig. 2 steps of constructing in vitro cemented acetabular component A. use of theacetabular reamer tray as a mold after dictating size of the acetabulum and a sterilesofratol sheet is used to line reamer tray; B. antibiotic-impregnatedpolymethylmethacrylate is then mixed and applied in the doughy phase in the trayreamer; C, D. definite polyethylene liner (the smallest diameter that matches 28mm head)is inserted in the tray reamer till polymerization is completed; E & F in-vitro cementedpolyethylene construct that matches the size of acetabulumFor the femoral component: the stem of the trial spacer G, that mimics the femoral canaldiameter, is wrapped entirely with Vaseline paper found within the sterile sofratol pack, andpolymethylmethacrylate is applied over the trial spacer stem, till polymerization is completedand the trial spacer is then extracted to get a polymethylmethacrylate mold for the femoral canaldiameter (Fig 3).Fig. 3 Cement mold for the femoral component A, B - the stem of the trial spacer G, thatmimics the femoral canal diameter, is wrapped entirely with Vaseline paper; C-polymethylmethacrylate is applied over the trial spacer stem, till polymerization iscompleted; D, E- the trial spacer is then extracted to get a polymethylmethacrylate moldfor the femoral canal diameterThe smallest definite femoral stem is then cemented with antibiotic-impregnatedpolymethylmethacrylate within the mold which is lined from the inside with Vaseline paper.After polymerization, the outer mold is pealed from around the cemented stem which now has acement mantle that fits into the femoral canal diameter (Fig 4)Fig 4 A-D Femoral stem construct A. Femoral stem & mold; B. the smallest definitefemoral stem is then cemented with antibiotic-impregnated polymethylmethacrylatewithin the mold which is lined from the inside with Vaseline paper; C. Afterfile:///E|/ISTA2010-Abstracts.htm[12/7/2011 3:15:47 PM]