RESUMO
STUDY DESIGN: Cohort study. PURPOSE: There is currently no published study that focuses on the spinal corrective surgery effects with cranial parameters in adult spinal deformity (ASD) patients. It is an important factor to measure since it plays a critical role in maintaining the line of sight. The objective is to determine the change in cranial parameters using the slope of McGregor's line (McGS) after ASD surgery after 2 years of follow-up. OVERVIEW OF LITERATURE: A study concluded that cervical spine alignment (C2-C7 lordosis) is strongly affected by thoracic kyphosis (TK). Another study showed that patients with ascending gaze had significantly more thoracolumbar malalignment. METHODS: This retrospective study includes 295 corrective surgery patients with ASD. Subjects were divided into two groups after propensity age matching analysis: cranial malalignment (McGS <-8 or >13) and normal cranial alignment (-8≤ McGS ≤13). Lumbar lordosis (LL), pelvic tilt (PT), TK, cervical lordosis (CL), and sagittal vertical axis (SVA) were evaluated between the two groups. RESULTS: SVA (95-56 mm) and PT (34°-25°) decreased and LL (19°-41°) increased 2 years after surgery (p <0.05), but McGS (-1.1° to -0.5°) and CL (21°-19°) did not change. Conversely, in the group with cranial malalignment, SVA (120-64 mm), PT (35°-26°), and LL (12°-41°) showed similar results to the normal cranial parameter group 2 years after surgery, but in contrast, McGS (-13° to -2°) and CL (24°-18°) improved significantly. CONCLUSIONS: Severe ASD adversely affects to maintain horizontal gaze but can be improved by spinal corrective surgery.
RESUMO
BACKGROUND: The purpose of study was to evaluate normal morphometric measurements of piriform aperture (PA) by limiting the age range in genders to show the morphometry of the relevant and close proximal cranial structures; and also to investigate whether these are in compliance with the golden ratio. MATERIALS AND METHODS: Our study was performed on 83 (42 female, 41 male) multidetector computed tomography images obtained from patients. A total of 14 morphological measurements were performed including the height of PA, the width of PA and 12 cranial structures; and these measurements were evaluated for compliance with the golden ratio. The differences of 14 parameters between the genders and age groups, and also the interaction of these two factors were analysed. RESULTS: In our morphometric study, significant difference between the genders was found in all measurements except for the distance between vertex and rhinion (V~Rh), between rhinion and right foramen supraorbitalis (Rh~FSOR), between rhinion and left FSO (Rh~FSOL), and the width of PA on the level between the right and left foramen infraorbitalis (PAW~FIO) with the difference valid for both age subgroups (p < 0.05). When the differences between the age subgroups were evaluated, there was significant difference only at the widest distance of cranium (CW; p = 0.008); and it was observed that the average has increased with age in both genders. When the golden ratio was examined, the ratio of the distance between anterior nasal spine and nasion to the height of piriform aperture (NSA~N:PAH) was found to be within the limits of the golden ratio in males (p = 0.074). No golden ratio has been found in females. CONCLUSIONS: In our study, significant differences were detected between genders in all parameters of PA and in some parameters of the close cranial structures in the age group we examined. The effect of age was detected only in the CW parameter, and the PA and close cranial structures were not affected. In our study, the averages of the morphometric measurements of 13 parameters of young adults were determined. The PA and surrounding cranial structures are important for the area and related surgical procedures; however, gender differences must be considered in this respect. In addition to this, in the PA, which is the anterior limit of the skeletal nose in males, the NSA~N:PAH ratio having the ideal golden ratio limits is valuable in aesthetical terms and due to its position of the PA in the face.