Comparison of Effectiveness between Cobalt Chromium Rods versus Titanium Rods for Treatment of Patients with Spinal Deformity: A Systematic Review and Meta-Analysis

Abstract

Background. Biomechanical properties of rods determine their ability to correct spinal deformity and prevention of postoperative sagittal and coronal changes. The selection of a proper rod material is crucial due to their specific mechanical properties that influence the surgical outcome. The purpose of this study is to compare the effectiveness of cobalt chromium rods versus titanium rods for the treatment of spinal deformity by a systematic review and meta-analysis. Methods. PubMed, EMBASE, and the Cochrane library were searched for observational and biomechanical studies comparing cobalt chromium and titanium rods in terms of correction rate, thoracic kyphosis, lumbar lordosis, incidence of rod fracture, fatigue life of contoured rod, bending stiffness of rods, and occurrence of proximal junctional kyphosis. The demographic data and mean values of outcomes of interest were extracted from each group and compared by their mean difference as an overall outcome measure. The Review Manager software (RevMan 5.3) was utilized at a 95% significance level. Results. Eleven eligible studies with 641 participants for 7 observational studies and 35 samples for 4 biomechanical studies were identified. There were no significant differences between cobalt chromium and titanium rods in the correction rate of spinal deformity. Postoperative thoracic kyphosis was well restored in the cobalt chromium group with statistical significance (p value = 0.009). The incidence of rod fracture was high in titanium rods compared to cobalt chromium rods with significant difference (p value = 0.0001). Proximal junctional kyphosis occurs more in the cobalt chromium group with a significant difference (p value = 0.0009). No statistical significance between two materials in terms of lumbar lordosis, fatigue of life, and bending stiffness of rods. Conclusion. The cobalt chromium rod is better than titanium rod for effective correction of spinal deformity and postoperative stability of the spine. However, the use of cobalt chromium rods is associated with increased risk of proximal junctional kyphosis.

Three-Column Osteotomy in Adult Spinal Deformity

“…In our study, among patients who had a 3CO, we found significantly higher usage of supplemental rods in Group II, and this may have contributed to the lower incidence of rod breakage. Other work indicated that the use of titanium rods was associated with a lower incidence of PJK compared with cobalt-chromium because of rod stiffness 26,27 . The usage of titanium rods was higher in Group II, while the use of cobalt-chromium remained constant, suggesting that the rod material may have also contributed to the diminished likelihood of PJF that we observed in this cohort.…”

Radiographic and clinical outcomes of robot-assisted pedicle screw instrumentation for adolescent idiopathic scoliosis

“…Due to the financial limitations imposed by our National Health Insurance system, titanium rod remains the sole option for posterior spinal instrumentation in our healthcare setting. Previous literature suggests that cobalt-chromium rods are generally considered better than titanium rods for effectively reducing the rate of rod fractures, correcting spinal deformities, and ensuring postoperative stability ( 27 , 28 ). Limited to using titanium rods, we need to increase pedicle screw density to effectively and safely perform the reduction by derotation technique with the rods.…”

Patient-specific rods in adult spinal deformity: a systematic review

“…Barton, Solla, and Farah used titanium rods, Kleck and Prost and Pesenti did not specify, Prost and Farah used titanium rods for 47 patients with cobalt chromium rods for the other 39 and Sadrameli used all cobalt chromium rods. The cobalt chromium rods are stiffer and believed to obtain higher rates of deformity correction but associated with an increased risk of proximal junctional kyphosis [ 45 ]. Construct properties such as screw type/number/placement, hooks, and cross connectors were only reported in one included manuscript despite being known to affect complication rates [ 46 ].…”