The Retrospective Survey of Corrosion Amount Inside The Tissue of Spinal Surgery Used Titanium Pedicle Screws in Time

Our study is aiming retrospective survey of the corrosion resistence of above-stated silver andhydroxyapatite covered pedicle screws depending on routinely surgery used Ti and Ti-6Al-4V compoundedpedicle screws. 32 pedicle screw coverings in different sizes removed after the revision surgery were separated into three groups (Ti-6Al-4V, Silver Covering and Hydroxyapatite Covering). Screws in every groupwere measured in order of diameter (mm) and severity (gram). The implanted residence times (day) of pedicle screws in patients were recorded by using patient records. According to the results, we observed that silver and hydroxyapatite covered pedicle screws and time have a correlation relation in a positive way.However, this situation is total opposite for Ti-6Al-4V pedicle screws. Any correlation relation in a positiveway between severity difference and time wasn’t found in any pedicle screw group. Hydroxyapatite and