Cervical sagittal alignment in patients with adolescent idiopathic scoliosis: is it corrected by surgery?

Abstract

<jats:sec><jats:title>OBJECTIVE</jats:title><jats:p>Cervical sagittal alignment (CSA) is related to function and quality of life, but it has not been frequently studied in patients with adolescent idiopathic scoliosis. This study aimed to reveal the change in CSA following corrective surgery, compare the cervical sagittal parameters according to curve types, and assess related factors for postoperative aggravation of CSA.</jats:p></jats:sec><jats:sec><jats:title>METHODS</jats:title><jats:p>The authors studied 318 consecutive patients with adolescent idiopathic scoliosis who underwent corrective surgery at a single center. Occiput–C2 and C2–7 lordosis, C2–7 sagittal vertical axis (SVA), T-1 slope, thoracic kyphosis, and lumbar sagittal profiles were measured preoperatively and postoperatively. Scoliosis Research Society Outcomes Questionnaire (SRS-22) scores were used as clinical outcomes. Each radiological parameter was compared preoperatively and postoperatively according to curve types (double major, single thoracic, and double thoracic curves). Patients were grouped based on preoperative CSA: the lordotic group (group L) and the kyphotic group (group K). Each radiological parameter was compared between the groups. Related factors for postoperative aggravation of CSA were assessed using multivariate logistic analysis.</jats:p></jats:sec><jats:sec><jats:title>RESULTS</jats:title><jats:p>Of the total number of patients studied, 67.0% (213 of 318) and 54.4% (173 of 318) showed cervical kyphotic alignment preoperatively and postoperatively, respectively. C2–7 lordosis increased (from −5.8° to −1.1°; p &lt; 0.001) and C2–7 SVA decreased (from 24.2 to 20.0 mm; p &lt; 0.001) postoperatively regardless of curve types. Although group K showed improvement in C2–7 lordosis (from −12.7° to −4.8°; p &lt; 0.001), group L showed no difference (from 9.0° to 6.9°; p = 0.115) postoperatively. Clinical outcomes were not related to the degree of cervical kyphosis in this cohort. C2–7 lordosis (p &lt; 0.001) and pelvic tilt (p = 0.019) were related to postoperative aggravation of CSA.</jats:p></jats:sec><jats:sec><jats:title>CONCLUSIONS</jats:title><jats:p>Regardless of the trend of improvement in CSA, many patients (54.4%) still showed cervical kyphotic alignment postoperatively. C2–7 lordosis and C2–7 SVA improved postoperatively in all curve types. However, postoperative changes in C2–7 lordosis showed different results based on preoperative CSA, which could be related to T-1 slope and thoracic kyphosis. However, clinical outcomes showed no difference based on CSA in this study cohort. Greater C2–7 lordosis and proximal thoracic curve preoperatively were risk factors for postoperative aggravation of CSA (p &lt; 0.001 and p = 0.019, respectively).</jats:p></jats:sec>

Sagittal Plane Deformities in Children with SMA2 following Posterior Spinal Instrumentation

“…In doing so, we demonstrated that these deformities are relatively common and that they are not associated with changes in lumbar lordosis (Table 6 and Figure 4). Similar changes in sagittal alignment have been described cephalad [33][34][35][36][37][38][39] and/or caudal [40][41][42] to posterior instrumentation in children with adolescent idiopathic scoliosis. However, we are not aware of any other reports describing these changes we have observed in the SMA population.…”

Cervical sagittal alignment and the impact of posterior spinal instrumented fusion in patients with Lenke type 1 adolescent idiopathic scoliosis

“…More recently, restoring sagittal alignment has also received increasing attention in AIS patients, correlating with positive health-related quality of life (HRQOL) outcomes in multiple studies (3,4). Additionally, it has been suggested that a dynamic inter-play may exist between the degree of thoracic kyphosis and nearby cervical and lumbar curvatures (1,2,(5)(6)(7)(8)(9)(10)(11). Multiple studies have emphasized the importance of restoring thoracic kyphosis in the hypo-kyphotic AIS patients to maintain a normal lumbar lordosis (3,12,13).…”

“…In this realm, cervical sagittal alignment (CSA) has also emerged as one of the variables that may correlate with clinical and functional outcomes in AIS patients undergoing surgical correction (5,6,8,10,11). Previous studies have noted a prevalence of cervical kyphosis in the AIS population, and that thoracolumbar fusion results in alternations in cervical sagittal profile (15)(16)(17).…”

Cervical Spinal Cord Compression in Adult Scoliosis

“…Straightened or kyphotic cervical alignment is well recognized in cases with AIS, [6][7][8][9] and not only the thoracolumbar spine but also the cervical spine is affected in AIS. Although scoliosis progressed even after adulthood in AIS, 15,16 the current study found that the sagittal alignment also altered, and the risk of cervical SCC increased.…”