title: Ultrasound-guided aspiration and corticosteroid injection of Baker's cysts in knee osteoarthritis: a prospective observational study.
abstract: OBJECTIVE
  To determine the effect on pain, function, and ultrasonographic findings of ultrasonography-guided Baker's cyst aspiration followed by corticosteroid injection in a group of patients with Baker's cyst secondary to knee osteoarthritis.
  
  
  METHODS
  Prospective observational study.
  
  
  RESULTS
  Twenty-six subjects participated in this study. Clinical and instrumental evaluations were performed at baseline (T0), 1 wk (T1), and 4 wks (T2) after procedure. Mean Visual Analog Scale scores significantly dropped after the procedure (T0 = 6.2 [1.2]; T1 = 4.48 [1.5]; T2 = 4.32 [1.3]; T0 vs. T1 and P < 0.0001). A significant difference between preprocedure and postprocedure Western Ontario and McMaster Universities scores was found for pain (P < 0.0001) but not for joint stiffness (P = 0.7239) and disability (P = 0.6318). Ultrasonographic evaluation showed a significant reduction for both axial (P = 0.006) and sagittal (P = 0.01) areas of Baker's cyst, but no correlation was found between pain relief and Baker's cyst volume reduction.
  
  
  CONCLUSIONS
  Cyst aspiration with corticosteroid injection give pain relief and cyst volume reduction in patients with Baker's cyst and concomitant knee osteoarthritis. However, when compared with current literature, our results are similar to those obtained with intra-articular knee corticosteroid injection.
authors.affiliation: Physical Medicine and Rehabilitation Unit, Azienda Policlinico Umberto I, Rome, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Di Sante
authors.forename: Marco
authors.initials: M
authors.lastname: Paoloni
authors.forename: Francesco
authors.initials: F
authors.lastname: Ioppolo
authors.forename: Mauro
authors.initials: M
authors.lastname: Dimaggio
authors.forename: Sara
authors.initials: S
authors.lastname: Di Renzo
authors.forename: Valter
authors.initials: V
authors.lastname: Santilli
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D005260:Female; D005938:Glucocorticoids / Q000008:administration & dosage*; D006801:Humans; D007270:Injections, Intra-Articular; D008297:Male; D008775:Methylprednisolone / Q000008:administration & dosage / Q000031:analogs & derivatives*; D000077555:Methylprednisolone Acetate; D020370:Osteoarthritis, Knee / Q000150:complications; D010147:Pain Measurement; D011151:Popliteal Cyst / Q000000981:diagnostic imaging* / Q000628:therapy*; D011446:Prospective Studies; D013396:Suction; D018084:Ultrasonography, Interventional
chemical_list: D005938:Glucocorticoids; D000077555:Methylprednisolone Acetate; D008775:Methylprednisolone