Purpose: The aim of this study is to evaluate the levels of chromium (Cr), cobalt (Co), and titanium (Ti) after instrumented fusion for scoliosis.
Methods: Serum samples were collected at median 2.24 (range 0.1-38.8) years after fusion surgery for scoliosis in 91 individuals, of which 71 had been treated with steel implants and 20 with titanium implants. 91 sex and age-matched non-surgically treated individuals with scoliosis were used as controls. Levels of Cr, Co, and Ti were measured.
Results: In the 91 surgically treated individuals median levels of Cr were 0.54 µg/l vs 0 µg/l in the 91 controls, p < 0.001. Corresponding results for Co were 0.29 µg/l vs. 0.24 µg/l, p = 0.19, and for Ti were 0 µg/l vs. 0 µg/l, p < 0.001. In the individuals with steel implants and their corresponding controls median Cr levels were 0.63 µg/l vs. 0.00 µg/l, p < 0.001 and Co levels 0.27 µg/l vs. 0.23 µg/l, p = 0.36. No Ti was detected. In the individuals with titanium implants, median Cr levels were 0 µg/l vs. 0 µg/l in their corresponding controls, p = 0.38. Corresponding results for Co was 0.39 µg/l vs. 0.31 µg/l, p = 0.27 and for Ti 4.31 µg/l vs. 0 µg/l, p < 0.001. In the individuals with steel implants a negative correlation between implant time in situ and levels of Cr was found ([Formula: see text] = - 0.52, p < 0.001) but not with Co ([Formula: see text] = - 0.14, p = 0.23). Ti was not detected. In the individuals with titanium implants, there was no correlation between implant time in situ and levels of Cr ([Formula: see text] = 0.36, p = 0.12), Co ([Formula: see text] = - 0.12, p = 0.60) or Ti ([Formula: see text] = 0.22, p = 0.35).
Conclusion: The use of stainless steel and titanium implants in spinal fusion surgery is associated with elevated metal ion concentrations several years after surgery.
Keywords: Metal ions; Scoliosis; Spinal deformity; Spinal fusion; Spine surgery.
© 2022. The Author(s).