Custom Made Stem

In the late 1980s, custom-made stems were clinically applied based on the idea that it is important to reduce micromotion to obtain mechanical stability of cementless stems, which depends largely on the medullary cavity occupancy [1–3]. In these reports, partial mesh structures were used in the anteroposterior and posterior surfaces, but the results varied. In some reports, a method was presented in which a truck was placed next to the operating room and a stem-first procedure was performed to shorten the time required to insert the stem into the patient (Identifit, Stewal implants, Belgium, and Orthogenesis, Orlando, Florida), during a mold was taken from the medullary cavity was measured by laser, and the metal was shaved and disinfected in approximately 40 min in the truck [4]. However, many cases of mechanical loosening were reported in the short postoperative period because of the smooth surface of the stem without any surface treatment [5, 6]. This series of studies showed that stem stability is also affected by surface characteristics.