Automated radiographic hip morphology measurements: An open-access method.

Objective: The aim of this study is to present a newly developed automated method to determine radiographic measurements of hip morphology on dual-energy x-ray absorptiometry (DXA) images. The secondary aim was to compare the performance of the automated and manual measurements. Design: 30 DXA scans from 13-year-olds of the prospective population-based cohort study Generation R were randomly selected. The hip shape was outlined automatically using radiographic landmarks from which the acetabular depth-width ratio (ADR), acetabular index (AI), alpha angle (AA), Wiberg and lateral center edge angle (WCEA) (LCEA), extrusion index (EI), neck-shaft angle (NSA), and the triangular index (TI) were determined. Manual assessments were performed twice by two orthopedic surgeons. The agreement within and between observers and methods was visualized using Bland-Altman plots, and the reliability was studied using the intraclass correlation coefficient (ICC) with 95 % confidence intervals (CI). Results: The automated method was able to perform all radiographic hip morphology measurements. The intermethod reliability between the automated and manual measurements ranged from 0.57 to 0.96 and was comparable to or better than the manual interobserver reliability, except for the AI. Conclusion: This open-access, automated method allows fast and reproducible calculation of radiographic measurements of hip morphology on right hip DXA images. It is a promising tool for performing automated radiographic measurements of hip morphology in large population studies and clinical practice.

Reliability and agreement of manual and automated morphological radiographic hip measurements.

Objective: To determine the reliability and agreement of manual and automated morphological measurements, and agreement in morphological diagnoses. Methods: Thirty pelvic radiographs were randomly selected from the World COACH consortium. Manual and automated measurements of acetabular depth-width ratio (ADR), modified acetabular index (mAI), alpha angle (AA), Wiberg center edge angle (WCEA), lateral center edge angle (LCEA), extrusion index (EI), neck-shaft angle (NSA), and triangular index ratio (TIR) were performed. Bland-Altman plots and intraclass correlation coefficients (ICCs) were used to test reliability. Agreement in diagnosing acetabular dysplasia, pincer and cam morphology by manual and automated measurements was assessed using percentage agreement. Visualizations of all measurements were scored by a radiologist. Results: The Bland-Altman plots showed no to small mean differences between automated and manual measurements for all measurements except for ADR. Intraobserver ICCs of manual measurements ranged from 0.26 (95%-CI 0-0.57) for TIR to 0.95 (95%-CI 0.87-0.98) for LCEA. Interobserver ICCs of manual measurements ranged from 0.43 (95%-CI 0.10-0.68) for AA to 0.95 (95%-CI 0.86-0.98) for LCEA. Intermethod ICCs ranged from 0.46 (95%-CI 0.12-0.70) for AA to 0.89 (95%-CI 0.78-0.94) for LCEA. Radiographic diagnostic agreement ranged from 47% to 100% for the manual observers and 63%-96% for the automated method as assessed by the radiologist. Conclusion: The automated algorithm performed equally well compared to manual measurement by trained observers, attesting to its reliability and efficiency in rapidly computing morphological measurements. This validated method can aid clinical practice and accelerate hip osteoarthritis research.

Acetabular dysplasia and the risk of developing hip osteoarthritis at 2,5,8, and 10 years follow-up in a prospective nationwide cohort study (CHECK).

OBJECTIVE: To assess the relationship between acetabular dysplasia (AD) and the risk of incident and end-stage radiographic hip osteoarthritis (RHOA) over 2,5,8 and 10 years. DESIGN: Individuals (n = 1002) aged between 45 and 65 from the prospective Cohort Hip and Cohort Knee (CHECK) were studied. Anteroposterior pelvic radiographs were obtained at baseline and 2,5,8, and 10-years follow-up. False profile radiographs were obtained at baseline. AD was defined as a lateral center edge angle, an anterior center edge angle, or both <25° at baseline. The risk of developing RHOA was determined at each follow-up moment. Incident RHOA was defined by Kellgren & Lawrence (KL) grade ≥2 or total hip replacement (THR), end-stage RHOA by a KL grade ≥3 or THR. Associations were expressed in odds ratios (OR) using logistic regression with generalized estimating equations. RESULTS: AD was associated with the development of incident RHOA at 2 years follow-up (OR 2.46, 95% CI 1.00-6.04), 5 years follow-up (OR 2.28, 95% CI 1.20-4.31), and 8 years follow-up (OR 1.86, 95%CI 1.22-2.83). AD was only associated with end-stage RHOA at 5 years follow-up (OR 3.75, 95% CI 1.02-13.77). No statistically significant associations were observed between AD and RHOA at 10-years follow-up. CONCLUSION: Baseline AD in individuals between 45 and 65 years is associated with an increased risk of developing RHOA within 2- and 5 years. However, this association seems to weaken after 8 years and disappears after 10 years.