Evaluation of correction rates for titanium-alloy and cobalt-chrome-alloy rods in adolescent idiopathic scoliosis

Haresh F. Chaudhary, Manthan Soni, Kuldeep R. Chaudhary


Background: The customary treatment of AIS is spinal fusion with instrumentation using rigid rods. In parallel, agents such as, curve magnitude, points of fixation, level instrument selection, curve flexibility, kind of anchor rods used for patients and post-operative care are the main factors affecting the outcome of surgery.

Methods: A total 50 patients was included in the study. The control group, which included 31 patients treated with Ti rods, was compared with an experimental group of 19 patients treated with CCM rods. Correction surgery was performed through posterior approach using rod-rotation maneuver after inserting a pedicle screw in each vertebrae within the fusion. Six-millimeter CCM and six-millimeter Ti rods were used in experimental and control groups, respectively. Pre and postoperative indices of coronal alignment and sagittal alignment were measured.

Results: There was no statistical difference between the two groups for age, sex, Risser’s stage, preoperative Cobb’s angle, type and flexibility of curvature. The correction rate of thoracic curve was 71.4±10.2% for the CCM group and 71.8±6.1% for the Ti group. There were no statistical differences between the two groups for all coronal and sagittal factors (p>0.05).

Conclusions: AIS cases with double curvature, there was no statistically significant difference between Ti and CCM rods for coronal and sagittal plane correction rates. The derivations from biomechanical studies do not translate into clinical situations.


Adolescent idiopathic scoliosis, Correction surgery, Spinal implants, Titanium

Full Text:



Weinstein SL, Dolan LA, Cheng JC. Adolescent idiopathic scoliosis. Lancet. 2008;371:1527-37.

Anekstein Y, Mirovsky Y, Arnabitsky V. Reversing the concept: correction of adolescent idiopathic scoliosis using the convex rod de-rotation maneuver. Eur Spine J. 2012;21:1942-9.

Lafon Y, Lafage V, Dubousset J. Intraoperative three-dimensional correction during rod rotation technique. Spine. 2009;34:512-9.

Lamartina C, Petruzzi M, Macchia M. Role of rod diameter in comparison between only screws versus hooks and screws in posterior instrumentation of thoracic curve in idiopathic scoliosis. Eur Spine J. 2011;20:85-9.

Suk S-I. Pedicle screw instrumentation for adolescent idiopathic scoliosis: the insertion technique, the fusion levels and direct vertebral rotation. Clin Orthoped Surg. 2011;3:89-100.

Blondel B, Lafage V, Farcy J-P. Influence of screw type on initial coronal and sagittal radiological correction with hybrid constructs in adolescent idiopathic scoliosis. Correction priorities. Orthopaed Traumatol Surg Res. 2012;98:873-8.

Crawford AH, Lykissas MG, Gao X. All-pedicle screw versus hybrid instrumentation in adolescent idiopathic scoliosis surgery: a comparative radiographical study with a minimum 2-year follow-up. Spine. 2013;38:1199-208.

Jaquith BP, Chase A, Flinn P. Screws versus hooks: implant cost and deformity correction in adolescent idiopathic scoliosis. J Child Orthopaed. 2012;6:137-43.

Asher MA, Burton DC. Adolescent idiopathic scoliosis: natural history and long term treatment effects. Scoliosis. 2006;1(1):2.

Riedel MD, Glotzbecker MP, Vitale MG, Matsumoto H, Roye DP, Erickson M, et al. What's the evidence? Systematic literature review of risk factors and preventive strategies for surgical site infection following pediatric spine surgery. J Pediatr Orthop. 2013;33(5):479-87.

Binyamin G, Shafi BM, Mery CM. Biomaterials: a primer for surgeons. Sem Pediatr Surg. 2006:276-83.

Shida T, Koseki H, Yoda I. Adherence ability of Staphylococcus epidermidis on prosthetic biomaterials: an in vitro study. Int J Nanomed. 2013;8:3955.

Yasuyuki M, Kunihiro K, Kurissery S. Antibacterial properties of nine pure metals: a laboratory study using Staphylococcus aureus and Escherichia coli. Biofouling. 2010;26:851-8.

Binyamin G, Shaf BM, Mery CM. Biomaterials: a primer for surgeons. Semin Pediatr Surg. 2006;15:276-83.

Shida T. Adherence ability of Staphylococcus epidermidis on prosthetic biomaterials: an in vitro study. Int J Nanomed. 2013; 8:3955-61.

Yasuyuki M. Antibacterial properties of nine pure metals: a laboratory study using Staphylococcus aureus and Escherichia coli. Biofouling. 2010;26:851-8.

Suk S-I, Kim J-H, Kim S-S. Pedicle screw instrumentation in adolescent idiopathic scoliosis (AIS). Eur Spine J. 2012;21:13-22.

Malfair D, Flemming AK, Dvorak MF. Radiographic evaluation of scoliosis: review. Am J Roentgenol. 2010;194:S8-22.

Lee CS, Chung SS, Kang KC. Normal patterns of sagittal alignment of the spine in young adults radiological analysis in a Korean population. Spine. 2011;36:E1648-54.

Prince DE, Matsumoto H, Chan CM. The effect of rod diameter on correction of adolescent idiopathic scoliosis at two years follow-up. J Pediatr Orthoped. 2014;34:22-8.

Noshchenko A, Patel VV, Baldini T. Thermomechanical effects of spine surgery rods composed of different metals and alloys. Spine. 2011;36:870-8.

Miller A, Islam K, Grannum S, Morris S, Hutchinson J, Nelson I, et al. Cobalt chromium versus titanium alloy: has the change in scoliosis implant material improved deformity correction?. Orthopaed Proceed. 2018:96(Supp 6):20.

Lamerain M, Bachy M, Delpont M, Kabbaj R, Mary P, Vialle R. CoCr rodsprovide better frontal correction of adolescent idiopathic scoliosis treated by all-pedicle screw fixation. Eur Spine J. 2014;23(6):1190-6.

Angelliaume A, Ferrero E, Mazda K, Le Hanneur M, Accabled F, Gauzy JS. Titanium vs cobalt chromium: what is the best rod material to enhance adolescent idiopathic scoliosis correction with sublaminar bands. Eur Spine J. 2017;26(6):1732-8.

Hwang CJ, Lee CK, Chang BS, Kim MS, Yeom JS, Choi JM. Minimum 5-year follow-up results of skipped pedicle screw fixation for flexible idiopathic scoliosis. J Neurosurg Spine. 2011;15(2): 146-50.

Abul-Kasim K, Karlsson MK, Ohlin A. Increased rod stiffness improves the degree of deformity correction by segmental pedicle screw fixation in adolescent idiopathic scoliosis. Scoliosis. 2011;6:13.

Mazda K, Ilharreborde B, Even J, Lefevre Y, Fitoussi F, Penneçot GF. Efficacy and safety of posteromedial translation for correction of thoracic curves in adolescent idiopathic scoliosis using a new connection to the spine: the Universal Clamp. Eur Spine J. 2009;18(2):158-69.

Acar N, Karakasli A, Karaarslan AA, Ozcanhan MH, Ertem F, Erduran M. The mechanical effect of rod contouring on rod-screw system strength in spine fixation. J Korean Neurosurg Soc. 2016;59(5): 425-9.

Lamerain M, Bachy M, Dubory A, Kabbaj R, Scemama C, Vialle R. All-pedicle screw fixation with 6-mm-diameter cobalt-chromium rods provides optimized sagittal correction of adolescent idiopathic scoliosis. Clin Spine Surg. 2017;30 (7):E857-63.

Etemadifar MR, Andalib A, Rahimian A, Nodushan SMT. Cobalt chromium titanium rods versus titanium-titanium rods for treatment of adolescent idiopathic scoliosis; which type of rod has better postoperative outcomes?. Rev Assoc Med Bras. 1992;64:1085-90.