Aim of the work: Femoral revision component subsidence has been identified as predicting early 
failure in revision hip surgery. This comparative cohort study assessed the potential risk factors of 
subsidence in two commonly used femoral implant designs. Patients and Method: A comparative 
cohort study was undertaken, analyzing a consecutive series of patients following revision total hip 
arthroplasties using either a tapered-modular (TM) fluted titanium or a porous-coated cylindrical 
modular (PCM) titanium femoral component, between April 2006 and May 2018. Clinical and 
radiological assessment was compared for both treatment cohorts. Risk factors for subsidence were 
assessed and compared. Results: In total, 65 TM and 35 PCM cases were included. At mean followup of seven years (one to 13), subsidence was noted in both cohorts during the initial three months 
postoperatively (p < 0.001) then implants stabilized. Subsidence noted in 58.7% (38/65cases) of the 
TM cohort (mean 2.3 mm) compared to 48.8% (17/35) of PCM cohort (mean 1.9 mm; p = 0.344). 
Subsidence of PCM cohort were significantly associated with extended trochanteric osteotomy (ETO) 
(p < 0.041). Although the ETO was used less frequently in PCM stem cohort (7/35), subsidence was 
noted in 85% (6/7) of them. Significant improvement of the final mean Oxford Hip Score (OHS) was 
reported in both treatment groups (p < 0.001). Conclusion: Both modular TM and PCM revision 
femoral components subsided within the femur. TM implants subsided more frequently than PCM 
components if the femur was intact but with no difference in clinical outcomes. However, if an ETO 
is performed then a PCM component will subside significantly more and suggests the use of a TM 
implant may be advisable.