The 3-6-year results of a modular noncemented low-bending stiffness hip implant. A preliminary study.

A review of the 3-6-year clinical and radiographic results of a modular noncemented stem has been carried out. This is a three-part stem consisting of a head, stem, and proximal sleeve. The stems are split distally like a clothespin in the coronal plane to reduce bending stiffness. No mechanical failures have occurred, including no bead separation from the single-layer porous-coated taper lock sleeves. Of the 48 cases, 13 had smooth stems distally while the rest were fluted. Five of the fluted stems were solid, that is, nonsplit. Clinical results are 93.7% excellent, 4.2% good, and 2.1% poor with the Harris hip rating. There have been no revisions. Thigh pain incidence with the distal split stem was 4.4%. Radiographic follow-up evaluations revealed nonprogressive radiolucency around one of the ingrowth sleeves. When inserted in varus the smooth stems developed some radiolucency around the distal end. Fluting of the stem appeared to prevent this.