Ultrasonographic assessment of Baker's cysts after intra-articular corticosteroid injection in knee osteoarthritis.
OBJECTIVE
To assess sonographic changes in Baker's cysts (BCs) of patients with knee osteoarthritis after a single intra-articular corticosteroid injection.


METHODS
Thirty patients with knee osteoarthritis complicated with a symptomatic BC received a single intra-articular injection of 40 mg triamcinolone acetonide. Knee pain, swelling, and range of motion were evaluated. BC area and thickness of the cyst wall were measured with sonography before and 4 weeks after local treatment.


RESULTS
A significant improvement in knee pain, swelling, and range of motion after corticosteroid injection was accompanied by a decrease in size of the BCs as well as in thickness of the cyst wall as measured by sonography. Moreover, the reduction of BC area on sagittal scans after treatment was significantly correlated with the improvement in range of motion.


CONCLUSIONS
In this series of osteoarthritis patients, injection of corticosteroids inside the knee joint accounted for a reduction in BC dimensions as well as cyst wall thickness. Sonography can be used not only for the diagnosis of BCs but also to monitor response to therapy.
Department of Rheumatology, Fundación Jiménez Díaz, Madrid, Spain.
J Carlos
JC
Acebes
Olga
O
Sánchez-Pernaute
Alberto
A
Díaz-Oca
Gabriel
G
Herrero-Beaumont
D000305:Adrenal Cortex Hormones / Q000008:administration & dosage*; D000368:Aged; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007270:Injections, Intra-Articular; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000150:complications / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D011151:Popliteal Cyst / Q000150:complications / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D014463:Ultrasonography / Q000379:methods*
D000305:Adrenal Cortex Hormones; D000893:Anti-Inflammatory Agents