Differences among membranes induced by different implants and cements. Experimental study

Abstract

Background: The objective of this study is to analyze and compare the characteristics of the membranes that form around cement spacers; as well as the one that develops around titanium and steel implants. Materials and Methods: 20 rabbits were divided into 2 groups of 10. In Group 1, an antibiotic-coated cement spacer was placed on the right femur, and a titanium elastic nail (TEN) on the left one. In Group 2, an antibiotic/steroid-coated cement spacer was placed on the right femur, and a steel peg on the left one. At 6 weeks, the membranes were removed and its macroscopic, imaging, biochemical and histological characteristics were evaluated. Results: Macroscopy: The membrane induced by the ATB-coated cement spacer was significantly wider, whereas the one induced by the steroid-coated cement spacer and the TEN was very thin and adherent. Microscopy: The membrane induced by the steroid-coated cement spacer showed less inflammation (p = 0.0502) and was similar to the one induced by the steel peg (p = 0.322). Steel pegs showed greater epithelial proliferation (p = 0.026), which was scarce on the membrane induced by the steroid-coated cement spacer (p = 0.071). There was a mild tendency towards less active vascular proliferation (p = 0.107) in the group of the steroid-coated cement spacer vs. the one without steroids. There were no differences between the steel peg and the TEN (p = 0.737). X-rays and CT showed no significant differences (p = 0.988). In MRIs, most of the responses indicated lack of osseointegration in the steel peg group due to metallic artifacts. Conclusions: Different materials (titanium, steel and cement) with different agents added to them (antibiotics and steroids), alter the membranes both macroscopically and histologically. The steroidcoated cement spacer showed less inflammation and fibrosis, less vascular proliferation, and thinner and adherent membranes.

Keywords

• Espaciador de cemento
• membrana peri-implante
• membrana de Masquelet
• cemento con antibióticos. Cement spacer
• peri-implant membrane
• Masquelet membrane
• antibiotic-coated cement.