A mold assembly and method of forming a surgical implant from bone cement. The method has the steps of connecting a plurality of mold segments to approximate the size of a patient implant. Each mold segment has an open channel. The method may further include aligning the channels of connected mold segments, positioning a centralizing holder on a reinforcement member, mixing bone cement, pouring at least some bone cement through the channels and into connected mold segments, fitting the reinforcement member into the mold segments, curing the bone cement; and removing the cured surgical implant.