مقاله انگلیسی قاعده قابل پیش بینی برای انحنای کمری ایده آل
Abstract
Introduction
Materials and methods
Results
Discussion
Conclusion
Source of funding
Author contributions
Declaration of competing interest
Acknowledgement
References
Introduction
It is commonly accepted that sagittal spinopelvic balance is of prime importance for a great quality of life [1,2]. Among various regulatory mechanisms, modification of lumbar lordosis (LL) plays a major role in the maintenance of a well-balanced alignment of the sagittal plane [3e5]. Most surgical corrections for adult spinal deformity (ASD) diseases involve the fusion and reconstruction of lumbar segments, and acquisition of physiological lumbar alignment has been testified to remarkably reduce the occurrence of mechanical complications suffered after ASD surgery [6e8]. Therefore, the precise prediction of ideal LL has become increasingly important in clinical practice. First, many researchers believe that pelvic morphology, defined by pelvic incidence (PI), is a primary driver of lumbar alignment regulation [9,10]. Accordingly, Roussouly and colleagues [4] described four disparate types of lumbar alignment in light of the sacrum orientation and PI in a normal adult population; however, why a low PI or sacral slope (SS) is associated with two diverse kinds of lumbar shapes, type 1 (significant kyphosis and short lordosis) and type 2 (hypokyphosis and hypolordosis), remains in doubt (Figs. 1 and 2). In addition, some researchers tried to build a series of algorithms that inferred LL simply from PI, such as LL ¼ 0.67*PI þ 23.7 [1] and LL ; however, Sebaaly et al. [7] and Rose et al. [11] found that the above models failed to decrease the rate of mechanical complications or obtain a balanced sagittal alignment after ASD surgery. In contrast, they both acknowledged that the formula with a combination of PI and thoracic kyphosis would be more beneficial for improving surgical outcomes [7,11].The aforementioned evidence illustrates that the effect of TK on LL is indispensable. Therefore, it may be speculated that the lumbar spine needs to adjust its own sequence to concurrently match not only PI but also TK; on the other hand, surgeons should create optimal lumbar alignment to adapt these two structural components together during corrective operations [11,13]. However, most previous studies exclusively take into account the influence of PI and ignore the effect of TK when analysing lumbar alignment [9,10,14]; as a result, the efficacies of these pre-existing formulae are likely questionable. Recently, Pan et al. [13,14] published two papers that separately elucidated the reciprocal relationships of lumbar alignment with pelvic and thoracic morphology. On this basis, we aimed to further investigate the regulatory mechanisms within sagittal spinopelvic alignment and to forecast the theoretical values of lumbar parameters, comprehensively incorporating the impacts of PI and TK, by means of multiple linear regressions in asymptomatic adults.