Direct Vertebral Rotation (DVR) Does Not Improve Clinical and Radiological Results Compared to Differential Rod Contouring (DRC) in Patients Treated Surgically for Idiopathic Scoliosis

Abstract

Direct vertebral rotation (DVR) is the most widespread method to correct axial vertebral rotation. Differential rod contouring (DRC) also includes derotation, but not to the same extent as DVR. DVR requires additional surgical effort with potential consequences, which are absent in DRC; moreover, the data concerning the clinical benefits of apical derotation are not convincing. In the present study, clinical and radiological outcomes were compared in patients who underwent surgery for adolescent idiopathic scoliosis (AIS), having DVR and DRC vs. DRC only. In total, 73 AIS patients with curves of 40–85°, consecutively operated on by one surgeon, participated in this study and were followed up over 2 years. Scores from the SRS-22 questionnaire were analysed, the angles of trunk rotation (ATR) were measured with an inclinometer and a radiographic assessment of coronal and sagittal spinal profiles was conducted. In 38 cases, only DRC was performed, and in 35 DRC was performed and followed by DVR; the groups did not differ from an epidemiological point of view. Total SRS-22 scores after 2 years were similar in both groups (4.23 (±0.33) in DRC vs. 4.06 (±0.33) in DRC/DVR, p = 0.1). In all components of SRS-22, the differences were minor, with p being way above 0.05. The mean ATR in the DRC/DVR group was slightly smaller (8 ± 4°) than that of the DRC group (10 ± 5°), p = 0.16. Radiographic analysis did not show significant differences. The coronal curve was corrected by 66 ± 12% for DRC and 63 ± 15% for DVR, p = 0.28. Thoracic kyphosis in the DRC/DVR group increased by 1°, whereas in the DRC group the average kyphosis increased by 5° with a p value of 0.07. The complication rates were similar in both groups. This investigation did not show any advantages of the combination of DRC and DVR in scoliosis correction over DRC only, both radiologically and clinically, yet it affected intraoperative parameters, extending the operation time with only a minor increase in blood loss.

The Influence of Increased Pedicle Screw Diameter and Thicker Rods on Surgical Results in Adolescents Undergoing Posterior Spinal Fusion for Idiopathic Scoliosis

“…The correction of spinal deformities using modern systems based on the CD technique enriched with osteotomy techniques of the posterior column of the spine provides powerful opportunities for the correction and stabilization of curvatures [4,8,[10][11][12][13]. Many details of implants have evolved and been improved, such as the implant profile, screw head stiffness, mobility in the sagittal axis, and its multi-axial nature, to obtain the best possible correction results [20,21,37,38].…”

“…It is known from other biomechanical studies that the larger the screw diameter, the better the stabilization and the lower the risk of screw removal and implant loosening [20,23,[39][40][41]. For the surgical treatment of AIS, we received excellent outcomes using a system based on CD instrumentation in terms of three-dimensional correction of the spine (Figures 1-4 show X-rays of exemplary patients with idiopathic scoliosis after surgical treatment from G1 and G2), the coronal and sagittal planes, derotation, and the clinical outcomes [11][12][13]. It should be emphasized that the correction possibilities of spinal deformation are influenced by other factors that we did not analyze, such as bone quality, so we focused on assessing the results of surgical treatment based on the sizes of the screws and rods used [39][40][41].…”

“…With the ubiquity of medicine, spine surgery has also been developed. Modern surgical techniques allow for the correction of the curvature, stopping its progression and improving pain relief and social and physical functioning [8][9][10][11][12][13]. Since the introduction of Cotrel-Dubousset instrumentation, it has become the "gold standard" in the treatment of idiopathic scoliosis, with many modifications of implants and instruments allowing for the optimal correction of deformities [10,14].…”