DCM-J Natural-Hip System (Zimmer)

In total hip arthroplasty (THA), cemented stems with various designs and concepts, were used in the early twenty-first century. Among these, some reports on early loosening of polymethylmethacrylate (PMMA) Precoat stems with a collar were published [1–3]. A PMMA precoat was applied to the proximal portion of the stem to prevent debonding of the stem from the cement, and a collar was used to resist subsidence of the stem. Zimmer, the manufacturer of Precoat stems, started a new stem development plan for the U.S., Europe, and Japan in 2002 and established a new stem design policy based on a thorough literature review on (1) collars, (2) stem surface treatment, (3) cement mantle, and (4) stem cross-sectional shape.