Table 1: Between-groups comparison of ultrasonography and MRI findings in 80 patients with clinically suspected Baker cysts.

Patients with
arthritis
𝑛 = 1 7
Patients with
joint
hypermobility
𝑛 = 6
Others
𝑛 = 5 7
𝑃

Age, years10.4 ± 4.4 6 . 6 ± 2 . 5 8 . 2 ± 4 . 9 .075
Female sex, 𝑛 (%)8 (47%)0 (0%)26 (46%).090
Ultrasonography
 Joints examined, 𝑛 2812107
 BC all, 𝑛 16732.007
 BC bilateral, 𝑛 414.099
 Cyst volume, mL 3 . 9 ± 3 . 3 3 . 7 ± 2 . 0 3 . 2 ± 3 . 0 .471
 Anechogenic cysts, 𝑛 (% BC all)6 (37%)4 (57%)26 (81%).009
 Echogenic cysts w/o septations, 𝑛 (% BC all)10 (63%)3 (43%)6 (19%).009
 Synovitis, 𝑛 (% BC all)8 (50%)0 (0%)0 (0%)
 BC and joint effusion (% BC all)11 (69%)1 (14%)3 (9%)<.001
 BC communication with joint space, 𝑛 (% BC all)8 (50%)6 (86%)21 (66%).264
MR imaging
 Joints examined, 𝑛 6216
 BC all, 𝑛 527.134
 Cyst volume, mL 5 . 0 ± 2 . 4 4 . 0 ± 2 . 8 3 . 3 ± 3 . 1 .389
 BC and joint effusion (% BC all)4 (80%)0 (0%)1 (14%).056
 BC communication with joint space, 𝑛 (% BC all)5 (71%)2 (100%)7 (100%).615

US: ultrasonography, MR: magnetic resonance, and BC: Baker cyst. 𝑃 values were calculated with Chi-Square test, Fisher’s exact test, and Kruskal-Wallis test (age, cyst volume), as appropriate.