Abstract
Background: Over the past decade, several modifications have been introduced to uncemented femoral stems. The design of the stems, however, still classically fall under two categories: anatomical and straight. The purpose of this paper is to report the first clinical, radiographic and periprosthetic densitometry results of a cementless total hip arthroplasty performed with an off-the-shelf extended metaphyseal loading device
Fifty-eight consecutive patients who received aproximally loading non-cemented hip prosthesis were followed for an average of 4.4 years. Patients were clinically and radiographically followed at 3 weeks, 3 months, 6 months, 1 year and yearly thereafter. In addition, a group of 8 consecutive patients were studied with Dual X-Ray Absorptiometry Scans(DEXA) at the same intervals during the first year and at 18 months after surgery.
The extended proximal geometry of the device allowed for initial and secondary stability reflected by the low subsidence values over time. The maintenance of periprosthetic bone stock over time and the absence of stress shielding can be explained by the proximal loading pattern of the stem.
Correspondence should be addressed to Richard Komistek, PhD, International Society for Technology in Arthroplasty, PO Box 6564, Auburn, CA 95604, USA. E-mail: ista@pacbell.net
