Long-term tissue reactions following fracture internal fixation with crossing application of stainless steel versus titanium alloy
- Zhe-yi, Li
- Yong-hong, Zhang
Abstract
BACKGROUND:
Crossing application of stainless steel or titanium material is considered to induce severe electrolysis erosion. Most of studies regarding crossing application of stainless steel or titanium material focus on erosion of the metal implants in simulated human humoral environment or by metallurgy or chemistry.
OBJECTIVE:
To investigate the electrolysis erosion and the effects of crossing application of plates and screws made of stainless steel or Ti-6AL-4V (Ti) in the internal fixation on rabbit fracture healing.
DESIGN, TIME AND SETTING:
Randomized, controlled animal experiment was performed at the Animal Experimental Center and Central Laboratory of Shanxi Medical University between September 2007 and September 2008.
MATERIALS:
A total of 32 healthy adult New Zealand rabbits were selected.
METHODS:
The experimental rabbits with tibia fracture were randomly divided into four groups with 8 animals in each group. They were fixed with the different combinations of plates and screws made of stainless steel or Ti respectively: combination of Ti plates and Ti screws; combination of steel plates and steel screws; combination of Ti plates and steel screws; combination of steel plates and Ti screws. No external fixation was performed
MAIN OUTCOME MEASURES:
At the end of 12, 26, 39 and 52 weeks after internal fixation, inflammatory cell infiltration of soft tissues surrounding the internal fixation was detected; expression of proliferating cell nuclear antigens (PCNA) was determined by immunohistochemistry; speed of sound (SOS) at the fracture site was determined to evaluate fracture healing condition.
RESULTS:
After 12, 26, 39, 52 weeks of the operation, quantity of inflammatory cells and positive rate of PCNA in Ti plate and Ti screw group and Ti plate and steel screw group were significantly less than the other groups (P < 0.05); the thickness of fibrous capsule was smaller than steel plate and steel screw group and steel plate and Ti screw group (P < 0.05). There were no significant differences between Ti plate and Ti screw group and Ti plate and steel screw group or between steel plate and steel screw group and steel plate and Ti screw group (P > 0.05). The SOS showed that the different combinations of internal fixation materials had little influence on the healing of fractures (P > 0.05).
CONCLUSION:
Long-term biocompatibility of titanium alloy is better than stainless-steel, and there are no significant differences between crossing group and non-crossing group, which do not affect the healing of fractures.
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