Cobalt chromium-Titanium rods versus Titanium-Titanium rods for treatment of adolescent idiopathic scoliosis; which type of rod has better postoperative outcomes?

Abstract

SUMMARY OBJECTIVE; Compare the outcome of spinal deformity correction between Ti-Ti and CrCo-Ti rods for the treatment of spinal Adolescent Idiopathic Scoliosis (AIS) using rods mentioned with all pedicle screws and translation technique. METHOD; 59 patients operated for spinal deformity (Lenke 1 or 2) AIS. The patients were divided into two groups by random allocation using Ti-Ti rods (n = 29) and CrCo-Ti rods (n = 30) and the alone difference among them in the surgical procedure was rod material (Ti-Ti or CrCo-Ti rods) and finally, radiological outcomes were compared preoperatively, postoperatively and at last follow-up for 12 months. RESULTS; Patients’ main curve correction after surgical procedure regardless type of rod was 48.95±11.04 (13-75) degree. Success rate of spinal deformity correction following surgical procedure regardless of type of administered rod was 86.76 ± 11.30 percent (62.5-100%). Mean of deformity correction rate was 91.49±10.67% using CrCo-Ti rods versus 81.86±9.88% using Ti-Ti rods (P-value=0.01). Angle change was 3.29±6.60 for kyphosis angle and 0.59±7.76 for lordosis angle. Rate of main curve correction was not significantly different considering patients’ gender (P-value0.657). Main curve correction success rate was in association with patients’ age and type of rod (P-value=0.054, r=-1.863 and P-value=0.001, r=8.865 respectively). CONCLUSION; CrCo-Ti rods have the ability to produce higher correction rates in AIS compared to Ti-Ti rod of the same diameter. CrCo-Ti rods provide significant and stable spinal correction, especially in correction of main curve. This rate was associated with patients’ age and type of rod administered but not gender.

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

“…The results of our meta-analysis revealed no significant difference in the main curve correction rate of spinal deformity between cobalt chromium rods and titanium rods. These findings align with those reported by Etemadifar et al [ 26 ]; in their randomized clinical trial study on 59 patients, the authors concluded that cobalt chromium rods and titanium rods provide a similar significant primary curve correction rate, but the success rate of cobalt chromium rods was superior on spinal deformity correction. Results are also consistent with those reported by Watanabe et al [ 30 ] and Thompson et al [ 31 ] whereby no significant difference was observed in the correction rate between two groups implanted with titanium rods or cobalt chromium rods.…”

“…Serhan et al [ 29 ], in their biomechanical study of 80 rods, elucidated that cobalt chromium rod as compared with titanium rods has the ability to exert remarkable corrective forces on spinal deformity with less risk of developing rod deformation. Furthermore, in this study, we found that the postoperative thoracic kyphosis angle was well restored with the use of cobalt chromium rods than in the titanium rod group; there was a significant difference between them ( p value = 0.009); the results align with those reported by Etemadifar et al [ 26 ]. On the other hand, the findings of our study showed that there is no statistical significance in changes of lumbar lordosis with a p value of 0.77, which align with results reported by Han et al [ 17 ].…”

“…A total of fifteen full-text studies were identified through database searching for eligibility assessment. Four of these were excluded due to various reasons; Etemadifar et al [ 26 ] compared our outcome of interest but it was randomized clinical trial rather than observational or biomechanical study; Smith et al [ 27 ] assessed the risk factors for rod fracture and not rod fracture as an outcome; Slivka et al [ 28 ] did not compare the outcome of our interest; Serhan et al [ 29 ] was excluded because it did not assess the outcome of our interest. A total of eleven studies met the criteria for inclusion and included in our study.…”

“…Excluding one study as it was a randomized clinical trial conducted in Iran [ 26 ] has an impact on the statistical significance of thoracic kyphosis outcome results; however, the outcome results for deformity correction rate and lumbar lordosis did not change the statistical significance. When included, the new results were as follows: the overall mean difference of deformity correction rate was 1.57 (−3.32, 6.47), p value = 0.53, and I 2 = 64%; the overall mean difference of thoracic kyphosis was 1.77 (−-3.09, 6.62), p value = 0.48, and I 2 = 84%; the overall mean difference of lumbar lordosis was −0.85 (−3.30, 1.61), p value = 0.50, and I 2 = 0%.…”

“…Stainless steel with various diameters was previously commonly used but recently replaced by titanium rods and cobalt chromium rods [ 16 ]. The cobalt chromium gained popularity for correction of spinal deformity due to its higher mechanical strength hence less likely to have correction loss after surgery [ 26 ]. This study aimed to compare the effectiveness of cobalt chromium rods with titanium rods, in terms of their deformity correction rate; the occurrence of rod fracture; changes in thoracic kyphosis; changes in lumbar lordosis; and fatigue life of contoured rods and bending stiffness of rods, by systematic review and meta-analysis of available published literature.…”