Pediatric elbow measurement parameters: Evaluation of the six angles in inter- and intra-observer reliability

Abstract

Background: Several radiographic measurements of the humerus can be used to evaluate the treatment outcome of supracondylar fractures in children. Because of the cartilaginous nature of the immature elbow, interpretation of radiographs around this area is sometimes challenging and can be unreliable. This study was conducted to determine the inter-observer and intra-observer reliability of the six commonly used radiographic measurements of the distal humerus. Method: The Baumann angle, humero-ulna angle, metaphyseal-diaphyseal angle, radial epiphyseal angle, shaft-condylar angle and lateral capitellohumeral angle of the humerus were measured by two observers on the radiographs of uninjured elbows from 58 children. The values between each measurement were compared and correlated using a Pearson coefficient of correlation to determine the inter-observer and intra-observer reliability. Results: All of the radiographic parameters showed excellent intra-observer reliability with the correlation coefficient values of the Baumann angle, humero-ulna angle, metaphyseal-diaphyseal angle, radial epiphyseal angle, shaft-condylar angle, lateral capitellohumeral angle as 0.945, 0.95, 0.909, 0.888, 0.961 and 0.975 (p < 0.001), respectively. The inter-observer reliability of the Baumann and humero-ulna angles were also found to be highly correlated at r ¼ 0.843 (p < 0.001) and 0.878 (p < 0.001), respectively. The metaphyseal-diaphyseal angle had poor reliability with r ¼ 0.136 (p ¼ 0.291) while the radial epiphyseal angle, shaft-condylar angle, and lateral capitellohumeral angle demonstrated good reliability with r ¼ 0.675 (p < 0.001), 0.747 (p < 0.001), and 0.686 (p < 0.001), respectively. Conclusion: The Baumann angle and humero-ulna angle measurements of distal humerus showed excellent inter-and intra-observer reliability. Both parameters represent repeatable and reliable methods for determining the outcome of supracondylar humeral fractures in pediatric population.

Intra‐Observer and Inter‐Observer Reliability of Shaft Condylar Angle and Lateral Capitellohumeral Angle: Evaluation Based on Reliability in Different Ages and Levels of Experience

“…showed that all the AHL in the age range 0–5 years intersected with the middle one‐third of the capitellum, but in 30% of children under the age of 2 years, it intersected with the anterior one‐third of the capitellum. The previous reports provide evidence of the significance of the capitellum as one of the landmarks affecting reliability in elbow measurement.…”

“…A report of a late presented pediatric supracondylar fracture by Mulpruek et al . found that SCA can be the intraoperative reference for correction of sagittal alignment of the pediatric elbow. In terms of reliability, Suangyanon et al .…”

Comparison of Lateral and Crossed K-wires for Paediatric Supracondylar Fractures: A Retrospective Cohort Study

“…The lateral capitellohumeral angle (LCHA) is the angle between humeral shaft and the capitellum on lateral x-rays of the elbow and is a measure of the sagittal plane alignment [8]. The normal values of these angles were noted in several previous publications [9][10][11][12]. We used the values provided by Shank et al as reference values for comparison with the BA and LCHA on final clinical x-rays on our patient population as this was a good study that provided mean BA and LCHA in normal uninjured children along with standard deviation [9].…”

Assessment of Instant Loss of Elbow Flexion in Children with Untreated Gartland IIA Humeral Supracondylar Fractures—A Simulation Study with Lateral Elbow Radiographs

“…16 It has been reported that the anterior margin of the humeral cortex normally goes through the middle third of the capitellum in the lateral view of the elbow; 17 therefore, the relationship between the anterior margin of the humerus (AMH) and the capitellum may be used to depict the degree of elbow deformity. 18 To date, there have been no reports quantifying the possible loss of elbow motion based on the relationship between the AMH and capitellum using the lateral view. In this study, we simulated Gartland IIA SCFs in the lateral view of normal pediatric elbows.…”

“…However, this angle does not reflect clinical function loss 16 . It has been reported that the anterior margin of the humeral cortex normally goes through the middle third of the capitellum in the lateral view of the elbow; 17 therefore, the relationship between the anterior margin of the humerus (AMH) and the capitellum may be used to depict the degree of elbow deformity 18 …”