The development of whole blood titanium levels after instrumented spinal fusion – Is there a correlation between the number of fused segments and titanium levels?

Abstract

BackgroundMost modern spinal implants contain titanium and remain in the patient’s body permanently. Local and systemic effects such as tissue necrosis, osteolysis and malignant cell transformation caused by implants have been described. Increasing tissue concentration and whole blood levels of ions are necessary before a disease caused by a contaminant develops. The aim of the present study was the measurement of whole blood titanium levels and the evaluation of a possible correlation between these changes and the number of fused segments.MethodsA prospective study was designed to determine changes in whole blood titanium levels after spinal fusion and to analyze the correlation to the number of pedicle screws, cross connectors and interbody devices implanted.Blood samples were taken preoperatively in group I (n = 15), on the first, second and 10th day postoperatively, as well as 3 and 12 months after surgery.Group II (n = 16) served as a control group of volunteers who did not have any metal implants in the body. Blood samples were taken once in this group.The number of screw-rod-connections and the length of the spinal fusion were determined using radiographic pictures. This study was checked and approved by the ethical committee of the University of Tuebingen.ResultsThe mean age in group I was 47 ± 22 years (range 16 - 85 years). There were three male (20%) and twelve female (80%) patients. The median number of fused segments was 5 (range 1 to 11 segments).No statistically significant increase in the titanium level was seen 12 months after surgery (mean difference: -7.2 μg/l, 95% CI: -26.9 to 12.5 μg/l, p = 0.446). By observing the individual titanium levels, 4 out of 15 patients demonstrated an increase in titanium levels 12 months after surgery.No statistically significant correlation between fused segments (r = -0.188, p = 0.503) length of instrumentation (r = -0.329, p = 0.231), number of interbody devices (r = -0.202, p = 0.291) and increase of titanium levels over the observation period was seen.ConclusionsInstrumented spinal fusion does not lead to a statistically significant increase in whole blood titanium levels. There seems to be no correlation between the number of pedicle screws, cross connectors and interbody devices implanted and the increase of serum titanium levels.

Evaluation of Titanium Serum Levels in Patients After Spine Instrumentation: Comparison Between Posterolateral and 360º Spinal Fusion Surgery

“…They reported no statistically significant correlation between fused segments (r=-0.188, p=0.503), length of instrumentation (r=-0.329, p=0.231), number of interbody devices (r=-0.202, p=0.291), and increase of titanium levels over the observation period. They observed no statistically significant increase in titanium levels 12 months after surgery (mean difference=-7.2 μgL -1 , p=0.446) [25]. Those results are totally in contraposition with others in the literature and with ours too since not only do titanium levels not increase, but they decrease after surgery.…”

“…Metal liberation from metallic implants has been reported in the body fluids of patients carrying total hip or knee replacements, intramedullary nails, and, more recently, in patients undergoing instrumental spinal arthrodesis [2][3][11][12][14][15][19][20][21][22][23][24][25][26][27][28][29][30].…”

“…Metal ion release has been addressed in patients undergoing spinal surgery as correction of the deformity in adolescent idiopathic scoliosis literature or instrumented spinal arthrodesis [2][3]11,[25][26][27][28][29][30]. Localized metal debris has been well-documented in the paraspinal soft tissues surrounding instruments [3,5].…”

“…Richardson et al and Kasai et al reported 3.6-fold and 4-fold increases in the serum titanium levels of adult patients with instrumentation implanted on two or three levels of the lumbar spine[2,11]. Ipach et al also demonstrate 2 to 3-fold increases of titanium content in adult patients with a median of five fused segments[25].…”

Evaluation of Blood Titanium Levels and Total Bone Contact Area of Dental Implants

“…The same authors also indicated that preterm birth, stillbirth, death, or toxicity symptoms were not seen when pregnant rats were given TiO 2 nanoparticles [ 15 ]. Ipach et al [ 16 ] investigated whether the number of screws and connectors used in spinal surgery had any correlation with blood titanium levels. They found no correlation between blood titanium levels and the number of titanium implants used for the surgery.…”