Abstract
Purpose
Accolade TMZF® has the wedged taper shape and is fixed at the middle part. We testified the short term result of Accolade® and investigated the factor of subsidence.
Materials and Methods
We treated 21 hips in 20 patients (6 males and 15 females) with Accolade stem. The mean age was 61.2 years old (40–79 years old). The mean follow-up period was 11.1 months (6–23 months), and those within 5 months after operation were excluded. We measured the width of the stem and the canal of femur at the level of the upper and the lower end of lesser trochanter, and 1 cm above the tip of the stem at operation and at the last follow-up, then calculated the canal fill ratios. We also measured the distance between the tip of the stem and the proximal end of greater trochanter, then calibrated it by directly sizing the acetabular component. The value that subtracted the distance at the last follow-up from the distance at operation meant subsidence. We performed multiple regression study about weight and the canal fill ratio of stem at the level of lower end of lesser trochanter.
Results
The mean subsidence of the stem was 1.24 mm (0∼4.50 mm). The patients with 2 mm or more subsidence were four, and the patients with 1 mm or less subsidence were ten. There were no significant differences in weight and the canal fill ratio at the level of lower end of lesser trochanter, but the canal fill ratio of the stem tended to negatively correlate with subsidence.
Discussions and conclusions
Some authors reported the most important factors in predicting a failure of osteointegration were canal fill at the mid-third of the stem, canal fill at the distal-third of the stem, and canal flare index. Others reported large stem size was associated with subsidence. Our result showed the canal fill ratio at the level of lower end of lesser trochanter is associated with subsidence. Besides, Accolade® tended to result in more severe resorption of the proximal femur and lack of osteointegration. Accolade® had a good result in the short term evaluation, but we should observe the subsidence carefully because the proximal femur cortex inclines to resorption and the osteointegration doesn't ocuur.
