title: The fate of Baker's cyst after total knee arthroplasty.
abstract: OBJECTIVE
  It is widely held that most Baker's cysts resolve after treatment of the intra-articular knee pathology. The present study aimed to evaluate the fate of Baker's cysts and their associated symptoms after total knee arthroplasty (TKA).
  
  
  METHODS
  In this prospective cohort study, 102 patients with (105 were included, however three were lost to follow-up) an MRI-verified Baker's cyst, primary osteoarthritis and scheduled for TKA were included. Ultrasound was performed to evaluate the existence and the gross size of the cyst before and at one year after TKA. Additionally, associated symptoms of Baker's cyst were recorded pre- and post-operatively.
  
  
  RESULTS
  After one year, a Baker's cyst was still present in 87 patients (85%). There was a significant reduction in associated symptoms arising from the Baker's cyst before (71%) to after surgery (31%). No patients developed a new Baker's cyst associated symptoms. However, of the 72 patients who had reported Baker's cyst associated symptoms pre-operatively, 32 patients (44%) still complained of such symptoms one year after surgery.
  
  
  CONCLUSIONS
  Baker's cysts had resolved in only a small number of patients (15%) one year after TKA and symptoms from the cysts persisted in 31%. Cite this article: Bone Joint J 2016;98-B:1185-8.
authors: Hospital Märkisch Oderland, Sonnenburger Weg 3, 16269 Wriezen, Germany.
authors: H
authors: H
authors: Hommel
authors: Charité - University Medicine Berlin, Charitéplatz 1, 10117 Berlin, Germany.
authors: C
authors: C
authors: Perka
authors: Charité - University Medicine Berlin, Charitéplatz 1, 10117 Berlin, Germany.
authors: S
authors: S
authors: Kopf
mesh_terms: D000328:Adult; D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D001182:Arthroscopy / Q000379:methods; D015331:Cohort Studies; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000150:complications / Q000175:diagnosis / Q000601:surgery*; D010147:Pain Measurement; D011151:Popliteal Cyst / Q000150:complications / Q000175:diagnosis / Q000601:surgery*; D011446:Prospective Studies; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D013997:Time Factors; D016896:Treatment Outcome; D018608:Ultrasonography, Doppler
keywords: Baker’s cyst; Gastrocnemius-semimembranosus bursa; Osteoarthritis; Popliteal cyst; Total knee arthroplasty