A large metallic cyst caused by wear particles after total knee arthroplasty.
BACKGROUND
A symptomatic cyst is an uncommon complication after total knee arthroplasty (TKA). We present a case of a 77-year-old woman with a large cyst in the right knee caused by metal wear debris from the failure of a Miller-Galante I TKA performed 13 years earlier.


METHODS
The patient was treated with a two-stage operation including revision of the TKA followed by excision of the cyst, because there was a direct communication between the joint cavity and the cyst, and because the patient reported pain corresponding to the cystic area after revision. The patient was pain-free and had a satisfactory result 17 months after the second operation, without recurrence of cyst formation.


CONCLUSIONS
We recommend two-stage surgery in which the first-stage is correction of the intra-articular pathology with revision TKA and the second-stage is excision of the cyst.
Niimi
Rui
R
Department of Orthopaedic Surgery, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu City, Mie 514-8507, Japan.
Hasegawa
Masahiro
M
Sudo
Akihiro
A
Uchida
Atsumasa
A
D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D003560:Cysts / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology; D005260:Female; D005549:Foreign-Body Reaction / Q000000981:diagnostic imaging / Q000209:etiology*; D006801:Humans; D008670:Metals / Q000009:adverse effects*; D010329:Patella; D020959:Polyethylene / Q000009:adverse effects*; D011475:Prosthesis Failure; D011859:Radiography; D012086:Reoperation
D008670:Metals; D020959:Polyethylene