ArticleJournal of hip preservation surgery2025
Comparison of interobserver and Intraobserver reliability of alpha angle measurements using different types of circles for femoroacetabular impingement syndrome.
Article in Journal of hip preservation surgery, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
2 citing papers in PubMed.
- Defining the postoperative alpha angle threshold for improved outcomes in posterolateral cam lesions.Hip international : the journal of clinical and experimental research on hip pathology and therapy · 2026Article
- Rapid and reliable alpha angle measurement using a smartphone-based artificial intelligence system for cam-type femoroacetabular impingement.Journal of experimental orthopaedics · 2025Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
8 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
The alpha angle is a radiological measurement that has been proposed for the detection of cam morphology in patients suspected of femoroacetabular impingement syndrome (FAIS). After analysing published articles on FAIS, it is apparent that different types of circles are used in the measurement of alpha angles. To determine the interobserver and intraobserver reliability of alpha angle values measured using different types of circles on a 45° Dunn lateral radiograph in patients with symptomatic FAIS. The 45° Dunn lateral radiographs of the operated hips of patients who underwent hip preservation surgery in Dokuz Eylül University Hospital between 2014 and 2017 were evaluated retrospectively. Alpha angles were measured manually with transparent goniometers using three different circle types: thin full circle, thin-dashed circle, and thick full circle, and eye estimation without circle insertion. Measurements were made separately by an orthopaedist and a radiologist. A second measurement was made by the radiologist 1 month later for intraobserver reliability. Interobserver reliability for the thin full circle, thin-dashed circle, thick circle, and eye estimation (ICC = 0.645, 0.525, 0.494, and 0.588, respectively). Intraobserver reliability for the thin, thin-dashed, thick line, and eye estimation (ICC= 0.626, 0.681, 0.681, and 0.462 respectively). Interobserver difference of mean values of alpha angles for thin full, thin-dashed, thick full, and eye estimation were 2.7°, 0.9°, 1.1°, and 2.3°, respectively. Intraobserver differences between measurements were 1.5°, 0.9°, 0°, and 1.6°, respectively. Our study demonstrated that interobserver reliability is highest when measurements are made using a thin full circle.
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.