[Correlation analysis of Cobb angle and linear spinous process angle in adolescent idiopathic scoliosis].

OBJECTIVE: To analyze the correlation between Cobb angle and spinous process angle (SPA) on X-ray film and body surface in patients with mild to moderate adolescent idiopathic scoliosis(AIS). To explore the possibility of linear SPA to assess scoliosis. METHODS: Retrospective study for correlation of Cobb angle and linear SPA on X-ray film. AIS patients treated and taken full spine anteroposterior X-ray from January 2019 to December 2021 were analyzed correlation of Cobb angle and linear SPA on X-ray film. Prospective study for correlation of Cobb angle and body linear SPA. AIS patients treated and taken full spine anteroposterior X-ray from December 1 to December 9 this year were analyzed correlation of Cobb angle and body linear SPA. RESULTS: A total of 113 AIS patients with age an average of (14.02±2.16) years old(ranged from 10 to 18 years old) were recruited in retrospective study, involving 26 males and 87 females;there were 71 patients with mild AIS and 42 patients with moderate AIS. Cobb angle in AIS patients was significantly inversely associated with SPA(r=-0.564, P<0.001), the linear regression equation was:Cobb angle=169.444-0.878×SPA. Cobb angles in patients with mild scoliosis were significantly and inversely associated with SPA(r=-0.269, P=0.012), the linear regression equation was:Cobb angle=46.832-0.185×SPA. Cobb angles in patients with moderate scoliosis were also clearly correlated with SPA(r=-0.417, P=0.003), the linear regression equation was:Cobb angle=113.889-0.516×SPA. Thirty-eight patients were recruited in prospective study. The mean Cobb angle and body linear SPA were(18.70±6.98)°, ranged from 11.3° to 36.0° and (170.34±4.57)°, ranged from 162.1° to 177.7° respectively. There was significantly negative correlation(r=-0.651, P<0.001), the linear regression equation is:Cobb angle=187.91-0.99×SPA. CONCLUSION: Linear SPA on X-ray film or on the body was significantly negatively correlated with Cobb angles, but the regression equation fits poorly, so it's not suitable for diagnosis of scoliosis;however, linear SPA is appropriate for self-controlled assessment of scoliotic therapy or for dynamic assessment of spinal flexibility.

Correlation analysis of Cobb angle and linear spinous process angle in adolescent idiopathic scoliosis / 中国骨伤

OBJECTIVE@#To analyze the correlation between Cobb angle and spinous process angle (SPA) on X-ray film and body surface in patients with mild to moderate adolescent idiopathic scoliosis(AIS). To explore the possibility of linear SPA to assess scoliosis.@*METHODS@#Retrospective study for correlation of Cobb angle and linear SPA on X-ray film. AIS patients treated and taken full spine anteroposterior X-ray from January 2019 to December 2021 were analyzed correlation of Cobb angle and linear SPA on X-ray film. Prospective study for correlation of Cobb angle and body linear SPA. AIS patients treated and taken full spine anteroposterior X-ray from December 1 to December 9 this year were analyzed correlation of Cobb angle and body linear SPA.@*RESULTS@#A total of 113 AIS patients with age an average of (14.02±2.16) years old(ranged from 10 to 18 years old) were recruited in retrospective study, involving 26 males and 87 females;there were 71 patients with mild AIS and 42 patients with moderate AIS. Cobb angle in AIS patients was significantly inversely associated with SPA(r=-0.564, P<0.001), the linear regression equation was:Cobb angle=169.444-0.878×SPA. Cobb angles in patients with mild scoliosis were significantly and inversely associated with SPA(r=-0.269, P=0.012), the linear regression equation was:Cobb angle=46.832-0.185×SPA. Cobb angles in patients with moderate scoliosis were also clearly correlated with SPA(r=-0.417, P=0.003), the linear regression equation was:Cobb angle=113.889-0.516×SPA. Thirty-eight patients were recruited in prospective study. The mean Cobb angle and body linear SPA were(18.70±6.98)°, ranged from 11.3° to 36.0° and (170.34±4.57)°, ranged from 162.1° to 177.7° respectively. There was significantly negative correlation(r=-0.651, P<0.001), the linear regression equation is:Cobb angle=187.91-0.99×SPA.@*CONCLUSION@#Linear SPA on X-ray film or on the body was significantly negatively correlated with Cobb angles, but the regression equation fits poorly, so it's not suitable for diagnosis of scoliosis;however, linear SPA is appropriate for self-controlled assessment of scoliotic therapy or for dynamic assessment of spinal flexibility.

Is Radiation-Free Ultrasound Accurate for Quantitative Assessment of Spinal Deformity in Idiopathic Scoliosis (IS): A Detailed Analysis With EOS Radiography on 952 Patients.

Radiation exposure with repeated radiography required at follow-up poses serious health concerns for scoliosis patients. Although spinous process angle (SPA) measurement of spinal curvatures with ultrasound has been reported with promising results, an evidence-based account on its accuracy for translational application remains undefined. This prospective study involved 952 idiopathic scoliosis patients (75.7% female, mean age 16.7 ± 3.0 y, Cobb 28.7 ± 11.6°). Among 1432 curves (88.1%) detected by ultrasound, there was good correlation between radiologic Cobb angles measured manually on EOS (E_Cobb) whole-spine radiographs and automatic ultrasound SPA measurement for upper spinal curves (USCs) (r = 0.873, apices T7-T12/L1 intervertebral disc) and lower spinal curves (LSCs) (r = 0.740, apices L1 or below) (p < 0.001). Taller stature was associated with stronger correlation. For E_Cobb <30°, 66.6% USCs and 62.4% LSCs had absolute differences between E_Cobb and predicted Cobb angle calculated from SPA ≤5°. Ultrasound could be a viable option in lieu of radiography for measuring coronal curves with apices at T7 or lower and Cobb angle <30°.

A Preliminary Study of Estimation of Cobb's Angle From the Spinous Process Angle Using a Clinical Ultrasound Method.

BACKGROUND: Over a lifetime of having radiographs, a patient with adolescent idiopathic scoliosis (AIS) can be cumulatively exposed to high doses of ionizing radiation. Therefore, radiation-free, effective, and low-cost methods to screen and diagnose scoliosis have been sought for years. PURPOSE: This study aims to investigate the correlation between the Cobb's angle and the spinous process angle (SPA) and to study the feasibility of using clinical ultrasound images to estimate the Cobb's angle by measuring the SPA. STUDY DESIGN: This manuscript includes a retrospective and a prospective study. METHODS: In the retrospective study, radiographs from 43 subjects with AIS were used to investigate the correlation between the Cobb's angle and the SPA at the pre-brace and in-brace stages. Following this study, a prospective clinical ultrasound study was conducted on 33 subjects with AIS at the pre-brace stage to measure the SPA. RESULTS: High intra-rater and inter-rater reliabilities of radiograph measurements were found (ICC[3,3] = 0.97, ICC[2,3] = 0.91, p < .05). The clinical ultrasound measurements were also found to be highly reliable (ICC[3,3] = 0.91, p < .05). There was a significant correlation (r = 0.80 at the pre-brace stage and r = 0.87 at the in-brace stage, p < .05) between the Cobb's angle and the SPA measured from the radiograph measurements, whereas the SPA measured from ultrasound images were found highly correlated with that measured from the radiographs at the pre-brace stage (r = 0.90, p < .01). CONCLUSIONS: The findings of this study could support the new parameter (SPA) in the estimation of the Cobb's angle of a scoliotic curve in the coronal plane, and clinical ultrasound imaging could be developed and applied to assess scoliosis in a fast and noninvasive fashion. LEVEL OF EVIDENCE: Level III.

Intra- and Interobserver Reliability of the Cobb Angle-Vertebral Rotation Angle-Spinous Process Angle for Adolescent Idiopathic Scoliosis.

STUDY DESIGN: A reliability analysis of Cobb angle, vertebral rotation (VR), and spinous process angle (SPA) measurements in adolescent idiopathic scoliosis. OBJECTIVE: To determine the intra- and interobserver reliability of semi-automated digital radiograph measurements. SUMMARY OF BACKGROUND DATA: Cobb angle measurements on posteroanterior radiographs are commonly used to determine the severity of scoliosis. Vertebral rotation helps assess scoliosis 3-dimensionally and has a role in predicting curve progression. Recent studies have shown that the spinous process angle is a useful parameter in assessing scoliosis when using ultrasound imaging. Because the reliability of SPA measurements on radiographs has yet to be determined, it is important to compare the reliability of these 3 parameters (Cobb angle, VR, and SPA) using a computer assisted semi-automated method. METHODS: Sixty posteroanterior radiographs of patients with adolescent idiopathic scoliosis were obtained and measured twice by 3 observers who were blinded to their previous measurements, using an in-house developed program. Measurements were obtained using a semi-automated method to minimize variability resulting from observer reliability. The intra- and interobserver reliabilities were analyzed using intra-class correlation coefficients (ICCs) as well as Bland-Altman's bias and limits of agreement. RESULTS: Over 350 (intra) and 90 (inter) sets of curves with an average Cobb angle of 26° ± 9° (range, 10° to 44°) were compared for each parameter. Intra-observer reliabilities for each parameter were excellent (ICC[2,1], .82; 1.00), with mean absolute differences under 3° between most measurements. Interobserver reliability (ICC[2,1], .72; .95) was mostly good to excellent, with mean absolute differences ranging from 2.0° to 5.6°. CONCLUSIONS: Both the intra- and interobserver assessment of the Cobb, VR, and SPA from the semi-automated measurements had clinically acceptable reliability ranges and may be considered for clinical implementation. Additional studies will be conducted to determine the accuracy and sensitivity to change of these scoliosis severity measurements.