Can Arthroplasty Stem Influence Outcome: A Randomized Controlled Trial of Stem Length in Cemented Total Hip Arthroplasty

Background: The primary aim was to assess whether a short (125 millimeter (mm)) stem offered an equivalent hip-specific function compared to the standard (150 mm) stem when used for cemented total hip arthroplasty. Secondary aims were to evaluate health-related quality of life, patient satisfaction, stem height and alignment, as well as radiographic loosenings and complications between the two stems. Methods: A prospective twin-center double-blind randomized control trial was conducted. During a 15-month period, 220 patients undergoing total hip arthroplasty were randomized to either a standard (n = 110) or a short (n = 110) stem. There were no significant (P >=.065) differences in preoperative variables between the groups. Functional outcomes and radiographic assessment were undertaken at a mean of 1 and 2 years. Results: There were no differences (P =.428) in hip-specific function according to the mean Oxford hip scores at 1 year (primary endpoint) or at 2 years (P =.622) between the groups. The short stem group had greater varus angulation (0.9 degrees, P =.003) when compared to the standard group and were more likely (odds ratio 2.42, P =.002) to have varus stem alignment beyond one standard deviation from the mean. There were no significant (P >=.083) differences in the forgotten joint scores, EuroQol-5Dimension, EuroQol-visual analogue scale, short form 12, patient satisfaction, complications, stem height, or radiolucent zones at 1 or 2 years between the groups. Conclusion: The cemented short stem used in this study had equivalent hip-specific function, healthrelated quality of life, and patient satisfaction when compared to the standard stem at mean 2 years post operation. However, the short stem was associated with a greater rate of varus malalignment, which may influence future implant survival. (c) 2023 Elsevier Inc. All rights reserved.

Automated summary

This study found that using a short stem in cemented total hip arthroplasty was equivalent to using a standard stem in terms of hip-specific function, health-related quality of life, and patient satisfaction at a mean of 2 years post operation. However, the short stem was associated with a higher rate of varus malalignment, which may affect the implant's survival.