Does Ultra-Short Anatomic Cementless Stem Increase Revision Rates Compared to Contemporary Cemented Femoral Stem in Patients with Dorr Type C Femur?

Objectives: The optimal fixation strategy for femoral stems in patients with Dorr type C femora remains debated, with uncertainty about whether cementless or cemented methods achieve superior long-term stability. This study aimed to compare outcomes between a proximally loading, short anatomic cementless stem and a contemporary cemented stems in patients with this femoral morphology. Methods: A total of 200 patients (224 hips) were enrolled in this randomized controlled trial with half receiving a proximally loading short anatomic cementless Total Hip Arthroplasty (THA) and other half treated with a contemporary cemented THA. There were 53 men and 47 women (mean age, 71.2 years) in the cementless THA group and 55 men and 45 women (mean age, 72.4 years) in the cemented THA group. Clinical outcomes were prospectively evaluated. The average follow-up was 17.5 years (range, 15 to 20 years) in the cementless group and 18.8 years (range, 15 to 22 years) in the cemented group. Results: At final review, both groups demonstrated comparable functional outcomes. Harris hip scores averaged 92 in the cementless group, and 93 in the cemented group, WOMAC scores were 15 versus 12, and UCLA activity scores were 8 versus 7. Cortical Thickness Index (CTI) values were nearly identical (0.71 vs 0.73, P = 0.528). Femoral stem revision was required in 4.5% of the cementless hips and 3.5% of the cemented hips. Kaplan-Meier analysis estimated femoral component survivorship was 95.5% for cementless stems at 17.5 years and 96.5% for cemented stems at 18.8 years. Conclusions: Both the ultra-short anatomic cementless design and the cemented femoral stem yielded durable fixation and excellent long-term survivorship in patients with Dorr type C femora.