Comprehensive analysis of pediatric elbow radiographic lines and angles

Objective:

The study aimed to determine relevant radiographic lines and angles of children's elbow

Methods:

Design:

A retrospective cross-sectional study

Setting:

Tertiary pediatric trauma center

Patient Selection Criteria:

X-rays of healthy children's elbows aged 0-18 years, in whom the radiographic image of the elbow in two projections was read without signs of fracture and possible indirect signs of fracture, while the exclusion criterion was a clearly visible poor image projection.

Outcome Measures and Comparisons: Gender, age [patients were divided into six groups -group 1 (0-3 years), group 2 (4-6 years), group 3 (7-9 years), group 4 (10-12 years), group 5 (13-15 years), group 6 (16-18 years)], side, intersection of the radiocapitellar line in the anteroposterior projection, intersection of the radiocapitellar line in the lateral projection, intersection of the anterior humeral line, Baumann angle, carrying angle, lateral capitellohumeral angle, shaft condylar angle, intersection of the coronoid line and radioulnar overlap.

Results:

200 elbows were evaluated. The radiocapitellar line in AP and lateral projections passed through the middle third of the capitellum in 74.5% and 93%, respectively. The anterior humeral line passed through the middle third of the capitellum in 88.5% of cases. When observing the proportion of radiocapitellar lines passing through the middle third of the capitellum in the AP, with increasing age an increasing proportion of lines pass through the middle third of the capitellum [from 8.3% in group 1 (0 to 3 years) to 94.1% in group 6 (16 to 18 years), p = 0.001] and lateral projection (from 50% in group 1 to 100% in group 6, p = 0.023) and anterior humeral line (from 25% in group 1 to 100% in group 6, p = 0.0001). The mean Baumman angle, carrying angle, lateral capitellohumeral angle, shaft condylar angle were 71.59°, 10.97°, 50.84°, and 55.31°, respectively. With age, the shaft condylar angle records the greatest increase (from 41.6° in group 1 to 68.2° in group 6, p = 0.000). A correlation was observed between Baumann's angle and carrying angle (r = - 0.674) and between Baumann's angle and radioulnar overlap (r = 0.542).

Conclusions:

Considering the anatomical variability of children's elbow, radiological measurements and their interpretation, in the context of timely diagnostics, must be approached with great caution, especially in younger age groups, because it is with them that the largest proportion of lines and angles do not follow established principles.