Table 6.

Comparison of our study and other studies in the literature evaluating modular devices

Study	Study results	Our results
Goldberg et al. [12]	Modular head-neck taper Corrosion on taper n = 231 Corrosion increases with implantation time	Figure 3 depicts implantation time with severity of corrosion
Salvati et al. [21]	n = 48 Corrosion correlates with implantation time	As above
Dunbar [7]	Neck stress dependent on length and offset and relates to propensity of fretting and corrosion	Determination of fretting at the junction in response to higher applied stresses
Kretzer et al. [17]	Simulation study (n = 5) Mechanical loading of neck-stem junction leads to higher stresses	As above and when compared to the lack of fretting at the head-taper junction
Schramm et al. [22]	Simulation study of three devices Observations of fretting and corrosion	As above
Dunbar [7]	Neck fracture 1.4% (n = 5000)	As above, supporting our observations of the propensity for fretting in the joints
Atwood et al. [1]	n = 1 Fracture of a modular hip prosthesis Also cites FDA database from 2006	Again supports fretting at the junction, which also can lead to corrosion
Pallini et al. [19]	Load imposed by patient are equivalent to hammer blows	Premise that fretting is unlikely to occur as a function of inadequate location of the neck in theater
Jacobs et al. [13]	n = 20 Increased concentrations of circulating metal degradation products derived from orthopaedic implants may have deleterious biologic effects over the long term that warrant investigation	Linking the observed corrosion, fretting, and particulates in our study to a clinical consequence
Jacobs et al. [14]	n = 10 Debris that has a deleterious biologic effect comes from modular junctions	8 of 57 had metallosis including 2 ALVALs
Patntirapong et al. [20]	Laboratory study Effect of soluble Co and Cr ions on osteoclast differentiation and activation	Relates to our study with respect to the significance of the corrosion findings
Cameron [4]	Cites use of alternative methods to lock the taper	Even with secondary locking mechanisms (n = 27), fretting was observed (n = 15)
Fraitzl et al. [8]	S-ROM® devices (n = 22): cold welding 27% (n = 5)	Ti devices (n = 27): cold welding 22% (n = 4) S-ROM® devices (n = 15): cold welding 13% (n = 2)

FDA = US Food and Drug Administration; ALVAL = aseptic lymphocyte-laminated vascular-associated lesion.