TY - JOUR
T1 - Migration behaviour of 2 clinically excellent cementless stems with different design rationales
T2 - 5-year follow-up of a randomised RSA-study
AU - van der Voort, Paul
AU - van Delft, Danny
AU - Valstar, Edward R.
AU - Kaptein, Bart L.
AU - Fiocco, Marta
AU - Nelissen, Rob G.H.H.
N1 - Publisher Copyright:
© The Author(s) 2021.
PY - 2021/1
Y1 - 2021/1
N2 - Introduction: Excellent long-term survival has been reported for both the Taperloc and the Mallory-Head cementless stems. However, little is known about the migration behaviour of these stems which have different design rationales. The purpose of this randomised clinical trial was to compare the migration and clinical outcomes of these stems during 5 years of follow-up. Methods: 42 consecutive hips in 38 patients scheduled to receive cementless THA were randomised to either a Taperloc or a Mallory-Head stem. Evaluation took place preoperatively and postoperatively on the second day, at 6, 12, 26, and 52 weeks, and annually thereafter. Primary outcome was stem migration measured using roentgen stereophotogrammetric analysis (RSA) and secondary outcomes were the Harris Hip Score (HHS) and 36-Item Short-Form Health Survey (SF-36). No patients were lost to follow-up; in 1 patient the THA was removed due to deep infection 3 months postoperatively. In 6 hips migration measurements were not possible due to insufficient marker configuration. Results: Throughout the follow-up period of 5 years, 3-dimensional migration was comparable between the Taperloc and the Mallory-Head stems (p-values > 0.05). However, at the 5-year follow-up point the retroversion of the Mallory-Head stem was 0.9° more than the Taperloc stem (p = 0.04). Initial subsidence and retroversion were respectively as large as 6.8 mm and 3.6° for the Taperloc stem and 5 mm and 3.6° for the Mallory-Head stem. After the first postoperative year, both implants had stabilised. The mean increment of HHS, as well as the SF-36 scores during the 5-year follow-up, were comparable between the 2 stems. Conclusions: The excellent long-term survival of both designs was confirmed in this study showing comparable initial migration with subsequent stabilisation. However, the Taperloc design with a flat, wedged geometry showed better rotational stability.
AB - Introduction: Excellent long-term survival has been reported for both the Taperloc and the Mallory-Head cementless stems. However, little is known about the migration behaviour of these stems which have different design rationales. The purpose of this randomised clinical trial was to compare the migration and clinical outcomes of these stems during 5 years of follow-up. Methods: 42 consecutive hips in 38 patients scheduled to receive cementless THA were randomised to either a Taperloc or a Mallory-Head stem. Evaluation took place preoperatively and postoperatively on the second day, at 6, 12, 26, and 52 weeks, and annually thereafter. Primary outcome was stem migration measured using roentgen stereophotogrammetric analysis (RSA) and secondary outcomes were the Harris Hip Score (HHS) and 36-Item Short-Form Health Survey (SF-36). No patients were lost to follow-up; in 1 patient the THA was removed due to deep infection 3 months postoperatively. In 6 hips migration measurements were not possible due to insufficient marker configuration. Results: Throughout the follow-up period of 5 years, 3-dimensional migration was comparable between the Taperloc and the Mallory-Head stems (p-values > 0.05). However, at the 5-year follow-up point the retroversion of the Mallory-Head stem was 0.9° more than the Taperloc stem (p = 0.04). Initial subsidence and retroversion were respectively as large as 6.8 mm and 3.6° for the Taperloc stem and 5 mm and 3.6° for the Mallory-Head stem. After the first postoperative year, both implants had stabilised. The mean increment of HHS, as well as the SF-36 scores during the 5-year follow-up, were comparable between the 2 stems. Conclusions: The excellent long-term survival of both designs was confirmed in this study showing comparable initial migration with subsequent stabilisation. However, the Taperloc design with a flat, wedged geometry showed better rotational stability.
KW - Randomised clinical trial
KW - Roentgen stereophotogrammetric analysis
KW - total hip arthroplasty
KW - Randomised clinical trial
KW - Roentgen stereophotogrammetric analysis
KW - total hip arthroplasty
UR - http://www.scopus.com/inward/record.url?scp=85101037380&partnerID=8YFLogxK
UR - https://www.mendeley.com/catalogue/3cab6c87-2638-3f8d-ae55-94b2f6e578ba/
U2 - 10.1177/1120700021995482
DO - 10.1177/1120700021995482
M3 - Article
C2 - 33596116
AN - SCOPUS:85101037380
SN - 1120-7000
VL - 32
SP - 747
EP - 758
JO - HIP International
JF - HIP International
IS - 6
ER -