Abstract
Cementless stem fixation is a widely used method of stem revision in North America and elsewhere in the World. There is abundant literature in its support. Most of the reports from 1985 to 2005 related to proximally or extensively porocoated designs, the former falling into disfavor with time because of unpredictable outcomes. With few exceptions (eg S-ROM) the modularity of these designs was limited to the head/neck junction. But this generation of designs was associated with some issues such as insertional fractures, limited control of anteversion (and risk of dislocation), limited applicability in the setting of severe bone loss (Paprosky Type 4 osteolysis or Vancouver Type B3 periprosthetic fracture), as well as ongoing concern relating to severe proximal stress shielding.
In the past decade we have seen the mounting use of a new design concept: tapered fluted titanium stems (TFTS), which incorporate the advantages of titanium (for less flexural rigidity), conical taper (for vertical taper-lock stability), longitudinal ribs and flutes (for rotational stability), and surface preparation which attracts bone on growth for long term fixation.
Four consecutive reports from our center have documented the superiority of the TFTS in our hands, with encouraging outcomes even when dealing with severe bone loss or periprosthetic fractures. There is an increasing body of other literature which reports a similar experience.
Furthermore, with increasing experience and confidence in this design, we now use a monoblock or non-modular design in greater than 95% of cases in which a TFTS is indicated at our center. This circumvents the potential drawbacks of stem modularity, including taper corrosion and taper junction fracture.
