Abstract: The present invention relates to method and apparatus for implanting and cementing the femoral stem component of a hip prosthesis. The process includes the steps of resecting the femoral neck, reaming a bore into the proximal medullary canal, enlarging that bore to accommodate the elongated stem of the femoral component, including the greater enlargement of the portion of the bore adjacent the transverse plane of the neck resection, establishing a peripheral shoulder in the cancellous bone of the medullary canal to seat a sealing plug, installing on the seat a perforable sealing plug, injecting the cavity with cement and implanting the femoral stem in the enlarged bore of the medullary canal by puncturing the sealing plug with the distal end of the stem and moving the stem distally further so that the sealing plug becomes a collar around the stem intermediate its ends.