In vivo and in vitro changes in strength of orthopedic calcium aluminates

✍ Scribed by Schnittgrund, G. D. ;Kenner, G. H. ;Brown, S. D.

• Publisher: John Wiley and Sons
• Year: 1973
• Tongue: English
• Weight: 831 KB
• Volume: 7
• Category: Article
• ISSN: 0021-9304
• DOI: 10.1002/jbm.820070327

✦ Synopsis

Abstract

Calcium aluminate bars were formulated to study the effect of real and simulated biological environments on strength. Static fatigue tests revealed that the strength of these potential internal bone prostheses decreased to ca. 60% of their initial strength after less than 100 min while being held at constant stress in solution. Calcium aluminate bars aged for 12 weeks in water or Ringer solution were also found to exhibit large losses in strength, while bars implanted in vivo for the same period of time weakened somewhat less. Semi‐quantitative analysis of the solutions in which the calcium aluminate bars were aged revealed that Al^3^+ and Ca^2^+ were being leached from the bars in both the saline and water baths, while the concentration of Mg^2^+ was decreasing in the Ringer solution.

Scanning electron microscope (SEM) studies revealed extensive microstructural changes in specimens aged in water or saline solution for 1 and 12 weeks. Similar but far less extensive changes were seen in bars aged in vivo in rabbits for 12 weeks.