Abstract
The fixation concept of a fluted, conical, tapered grit-blasted titanium stem has been employed successfully in Europe, but the experience in North America with implants of this design is more limited. The most commonly studied stem of this design, the Wagner stem has been reported to provide good pain relief function and implant stability in several aeries, although large series with long-term follow-up are lacking.
Implants with a similar distal geometry but modular proximal features were introduced in an attempt to solve one of the practical difficulties of using a stem of this design: determining where the implant would seat was difficult, trialing options were limited, and accurate leg length and soft tissue balancing were difficult. Modular implants are more user-friendly but have the theoretical disadvantage of introducing the potential for modular junction failure (failure due to fatigue or fretting). To date, there are only limited (but favourable) short-term reported results on the efficacy of this form of revision.
Implants of this design can be used when rotational stability, axial stability, and long-term implant fixation must be gained primarily from the distal diaphysis of the femur. Examples include patients with periprosthetic femur fractures and patients with marked proximal bone thinning but good diaphyseal bone.
From the practical viewpoint, the fluted section of these implants must be straight (to allow milling of a cone-shaped diaphysis) and thus anterior cortical perforation is a potential complication. Anterior extended osteotomy as described by Wagner accomplishes the goal of femoral exposure and helps prevent distal anterior femoral perforation.
The abstracts were prepared by Mrs Dorothy L. Granchi, Course Coordinator. Correspondence should be addressed to her at PMB 295, 8000 Plaza Boulevard, Mentor, Ohio 44060, USA.
