THE HIPSTAR STEM: SHORT-TERM CLINICAL AND RADIOLOGICAL RESULTS BASED ON 100 CONSECUTIVE CASES

Abstract

The Hipstar cementless system (Stryker) is a straight, wedge-shaped with a rectangular cross-section, titaniumalloy (TMZF) femoral component. This particular titaniumalloy (titanium, molybdeno, zirconium and iron) makes the stem 20% more resistant and less elastic than TiAlV alloy. The advantages are: a thinner neck with an equal resistant, an increase of range of motion, a reduction of impingement.

We examined 100 consecutive primary THRs between January 2002 and March 2004. The mean age was 69,9. Preoperative evaluation included a physical and radiographic examination. The acetabular component was the Trident cup (Stryker). Clinically, all the 100 hips were evaluated according to the scoring system of Harris. A patient’s evaluation test (WOMAC test) was also performed. At the time of the latest follow-up, standardized antero-posterior and axial radiographs of the pelvis and hip were made and evaluated according to Engh radiographic score. The median duration of follow-up was 24 months.

The median post-operative Harris Hip Score for 100 hips was 90.5. The observed mean value of WOMAC test score was 5,11. At the time of the latest follow-up, there was a bony incorporation of all components. We have had 2 cases of dislocation. At the latest follow-up no evidences of infection are present.