Coronal Imbalance in Adult Spinal Deformity Following Posterior Spinal Fusion With Instrument

Abstract

Study Design. A retrospective radiographic study. Objective. To explore the radiological parameters which correlated to postoperative immediately coronal imbalance in adult spinal deformity (ASD) and to determine whether preoperative coronal imbalance affects postoperative coronal imbalance following posterior multi-level fusion with instruments and osteotomy operation. Summary of Background Data. There was paucity of literature paying attention to the postoperative immediately coronal imbalance after operation. Methods. The study included 67 consecutive patients with ASD who underwent posterior multi-level fusion with instruments and osteotomy operation. The radiological parameters, measured on the pre- and postoperative anteroposterior and lateral radiographs, were compared and analyzed. Patients were divided into three groups (group A, B, and C) according to preoperative coronal balance distance (pre-CBD) and the relation of cervical 7 plumb line (C7PL), and the convex of curvature. To analyze the radiological parameters of the three groups. Result. Differences of the radiological parameters between pre- and postoperation concerning Cobb angles, degree of apical vertebra rotation, thoracic kyphosis (TK), thoracic lumber kyphosis (TLK), lumber lordosis (LL), sacral slope (SS), pelvic tilt (PT), and sagittal vertical axis (SVA), were significant (P < 0.05). Pelvic incidence (PI), pre-CBD, and postoperative coronal balance distance (post-CBD) had no change (P > 0.05). The ratio of coronal imbalance in pre- and postoperation was 31.34% (21/67) and 40.30% (27/67), respectively, which had significant difference (P = 0.02). Significant correlations were observed among post-CBD, pre-CBD (P < 0.001), and d-Cobb (pre-Cobb – post-Cobb) (P = 0.002), post-CBD = –2.737 – 0.924∗d-Cobb + 0.356∗pre-CBD. The ratio of postoperative immediately coronal imbalance of the group C was much higher than other two groups (P = 0.01). Conclusion. The sagittal alignments in ASD patients would be improved effectively after posterior multi-level fusion with instruments and osteotomy operation. There were significant correlations among post-CBD, pre-CBD, and d-Cobb. Patients in group C may be at greater risk for immediate postoperative coronal imbalance after operation. Level of Evidence: 3

Coronal balance with circumferential minimally invasive spinal deformity surgery for the treatment of degenerative scoliosis: are we leaning in the right direction?

“…In the study by Ploumis et al, 3 9 of 54 patients were in balance preoperatively and had developed new CM (defined as > 4 cm in their study) at last follow-up. Similarly, Zhang et al 6 reported that 16 of 51 patients in the type A category developed CM postoperatively (> 3 cm). Certainly, this finding does not suggest that cMIS is superior to open techniques in this group of patients, because there are likely to be considerable differences in our sample of patients that limit any direct comparisons between studies.…”

“…to make large sagittal corrections and restore lordosis in patients with adult spinal deformity, it has been demonstrated that the correction of coronal malalignment (CM) is often poor and leads to worse outcomes. [3][4][5][6] Interest in the correction of coronal alignment has recently been renewed. In 2016, Bao et al 5 described a classification of coronal imbalance and divided patients into groups on the basis of whether their C7 plumb line was neutral (type A), shifted toward the concavity (type B), or shifted toward the convexity (type C) of their scoliosis.…”

The predictor for Preoperative Coronal Imbalance in patients with Degenerative Lumbar Scoliosis--A related analysis on spinopelvic parameters

“…The increasing imbalance on the coronal plane in patients with degenerative lumbar scoliosis (DLS) has become one of main underlying factor that leads them to abnormal appearance, functional decline, and back pain [17] . The distance between C7 plumb line (C7PL) and central sacral vertical line (CSVL), named coronal balance difference [5] , coronal balance distance [12] , global coronal malalignment [14] , and C7 migration [11] , has been used to re ect coronal alignment. In this current study, we de ned the global coronal parameter as coronal balance distance (CBD).…”

“…Additionally, considering correction of main curve during long-fusion surgery in ASD patients, Zhang et al [12] suggested that there is signi cant correlation among pre-operative CBD, recti ed Cobb angle of main curves, and post-operative CBD. Unfortunately, they did not explore the relationship between major curve and CBD further.…”

“…3) Coronal balance distance(CBD) was de ned as the horizontal distance between the C7PL and the center of the S1 on coronal plane, C7PL on the left side of CSVL was recorded as negative(-), right side as positive(+). [12] 4) L4 coronal tilt, de ned as the angle between superior endplate of L4 and the horizontal line(left side was recorded as negative [-], right side as positive[+]). [5] 5) L5 coronal tilt, de ned as the angle between superior endplate of L5 and the horizontal line(left side was recorded as negative [-], right side as positive[+]).…”