The relationship between cobbs angle, Mean platelet volume and Neutrophil Lymphocyte ratio in adolescent idiopathic scoliosis

The scoliosis is the most common deformity of spine. The scoliosis is defined as lateral bending≥10° at frontal plane on direct supine radiographs. In the scoliosis, the deformity is not only limited to frontal plane but a 3-dimensional deformity occurs that involves sagittal and axial planes. There is intervertebral extension causing lateral bending at frontal plane, rotation at axial plane and lordosis at sagittal plane (1). Idiopathic scoliosis accounts for approximately 80% of structural scoliosis but the cause of deformity is unknown (1, 2).The etiology is unknown in adolescent idiopathic scoliosis (AIS). So far, many studies have been conducted to investigate etiology of scoliosis. Although many factors including hereditary factors, biomechanical factors, environmental factors, neuromuscular factors, vestibular dysfunction, asymmetric vertebral growth, collagen abnormality of nucleus pulposus, melatonin secretion and platelet micro-structure, dysfunction of growth hormone and paravertebral muscles have been implied, there is no proven factor in the etiology of scoliosis. As a result, the cause of scoliosis hasn't been fully elucidated. It is though that scoliosis is a multifactorial disorder rather than single factor (1, 3, 4). In the literature, some studies emphasized activity of calmodulin, a systemic mediator of contractile tissues, in paraspinal muscles (4). It has been discussed whether changes in platelet calmodulin reflecting abnormality in a part of spine are related to local and/or regional alterations in muscles, nervous system and immature vertebrates (5). In previous studies, platelet calmodulin level was considered as a useful predictor for progression of disease in patients with adolescent idiopathic scoliosis. In our study, we retrospectively reviewed approximately 15,000 patients who presented to our spine clinic between 2011 and 2018. The patient having both scoliosis radiographs and CBC were included and assigned into 3 groups. On anteroposterior scoliosis radiographs, angle of bending was measured by Cobb method. In addition, MPV and NLR were recorded and compared with Cobb angle. In our study, NLR were assessed by group comparison rate, revealing no significant difference (p=0,364). However, group comparison rate assessment showed significant difference regarding MPV (p=0.024). After adjusting age and sex, it was seen that the differences became more prominent in MPV. MPV value of group 3 was higher than controls by 0.402 unit (p=0.017). In conclusion, there was no significant difference in neutrophil: lymphocyte ratio between groups in AIS while MPV value was significantly higher in patients with scoliosis. It was found that MPV was significantly associated with Cobb angle. We believe that there is need for further studies with larger sample size to answer the question whether this relationship could be predictive for follow-up in AIS. Keywords: Adolescent idiopathic scoliosis (AIS), Neutrophil / Lymphocyte ratio (NLR), Mean Platelet Volume (MPV), Cobb angle