Subsidence of Modular Fluted Tapered Stems After Femoral Revision Surgery: Risk Factors and a Novel Classification...

Area of Science:

• Orthopedic surgery
• Biomedical engineering
• Radiology

Background:

• Modular fluted tapered (MFT) stems are utilized in femoral revision surgery for diaphyseal fixation.
• Bone loss in the femur presents challenges for achieving stable implant fixation.

Purpose of the Study:

• To identify factors contributing to MFT stem subsidence in femoral revision.
• To analyze the relationship between clinical variables and excessive subsidence.

Main Methods:

• Retrospective analysis of 180 femoral revision procedures using MFT stems.
• Radiographic analysis to measure stem subsidence over a mean follow-up of 28.5 months.
• Logistic regression and Bayesian modeling to examine subsidence risk factors.

Main Results:

• Mean subsidence at 12 months was 1.6 ± 2.3 mm; 8.3% of cases showed excessive subsidence (≥ 5 mm).
• Severe bone defects (Paprosky IIIA-IIIB) were strongly associated with excessive subsidence (OR = 6.35, P = 0.001).
• Short MFT stems, male sex, older age, higher weight, and greater height were identified as modulating factors for subsidence risk.

Conclusions:

• Short MFT stems and severe bone defects increase subsidence risk in femoral revision.
• Patient-specific factors (age, weight, height) influence subsidence.
• Personalized implant selection and regular radiographic monitoring are crucial for optimal outcomes.