Metallurgical analyses of failed orthopedic implants

Abstract

SummarySeveral metallic orthopedic implants which failed in service and for which the medical histories are known are comprehensively examined using metallographic techniques and electron microprobe analyses to determine the causes of failure. The results indicate that fatigue is a major cause of failure and that, in all probability, the fatigue is initiated by poor design or poor material.

Failure Analysis of PHILOS Plate Construct Used for Pantalar Arthrodesis Paper I—Analysis of the Plate

“…Non-metallic inclusions are known to be areas of stress concentration and increase the likelihood of pitting corrosion and secondary crack initiation. Sudhakar et al and Kanchanomi et al found that non-metallic inclusions initiated the eventual failure of devices in their studies [13,18]. This evidence of pitting and foreign body inclusions, seen in Figures 5 and 6, respectively, supports secondary crack initiation due to corrosion-fatigue at these sites.…”

“…In addition, successful fixation result in anatomic reduction, stable fixation, preservation of blood supply, and early mobilization [5][6][7][8][9] which occur with the use of locking compression technology. A summary of device failures was compiled from literature [10][11][12][13][14][15][16][17][18][19][20][21][22][23] (see Appendix A). It identifies the devices, material of construction, failure modes and other fracture features.…”

“…It is noteworthy that this may be the only case involving the failure analysis of PHILOS ( Figure 1). A number of studies involving SS316L material revealed inclusion sites as crack origins [10,[15][16][17][18], corrosion, wear and fatigue [10][11][12][13]15,16,18,19,21,23] with no visible mechanical failure yet having failed clinically [12,14]. The majority of the devices were constructed with SS 316 and 316L; however, a few devices constructed with Ti-6Al-4V alloy [19][20][21][22] and pure titanium [23] were also found.…”

Preliminaryin vivo report on the osteocompatibility of poly(anhydride-co-imides) evaluated in a tibial model

“…Metals and metal alloys produce oxidative products as a result of corrosion, leading to metal orthopedic applications we examined the bone tissue compatibility and the healing of 3-mm tibial bone defects in toxicity in tissues surrounding the implant. [2][3][4] In addition, the high rigidity of many metals at the interface have been shown rats over a 30-day period. The polymers consisted of poly-[trimellitylimidoglycine -co -1,6 -bis(carboxyphenoxy) -to cause bone atrophy from the stiffness mismatch between the implant and the surrounding bone.…”

“…These studies are the first to examine the potential of the poly(anhydridebiomaterials used for bone repair. [2][3][4][5][6][7][8][9][10] Although these materials have been beneficially utilized, they are also associated co-imides) as matrices used for bone regeneration in vivo.…”