“…Five studies [13,14,[21][22][23] (1,050 total patients) compared the elbow's range of motion (ROM) as an index test versus X-ray as a reference standard, four studies [24][25][26][27] (654 patients with fracture, 2,024 total) compared the ROM in elbow extension as an index test to X-ray as a reference standard, and three studies [28][29][30] (1,411 total patients) compared clinical clusters that included the evaluation of ROM in elbow extension and tenderness points to X-ray as a reference standard. In four studies [14,23,24,27], the values of +LR and −LR wer e also present, while, in eight studies [14,[21][22][23][24][25]27,29],VPP and VPN values were reported; in other cases, the data were extrapolated by the researchers (GDM and PC) using specific online calculators and added to the summary table of diagnostic accuracy values. Two studies [22,29] investigated this condition in children, and 10 studies investigated the same in children and in adults [13,14,21,[24][25][26]28,30].…”