title: Dissecting popliteal cyst resulting from a fragmented, dislodged metal part of the patellar component after total knee arthroplasty.
abstract: Dissecting popliteal cyst is an uncommon complication after total knee arthroplasty, occurring mainly as a result of either rheumatoid arthritis or a malfunctioning knee prosthesis. Its association with a failed metal-backed patellar component has not been reported since the introduction of the resurfacing of the patella with this kind of design in 1980. We present a case of a late fracture-dislocation of the metal part of the patellar component that migrated to the posterior popliteal fossa, resulting in a cystic mass formation caused by a foreign body granuloma. The patient was treated successfully with a 2-stage operation: first, revision of the total knee arthroplasty and, second, excision of the cyst. The patient had a pain-free functional knee 7 years after surgery, with no recurrence of the symptoms or the popliteal cyst.
authors.affiliation: Department of Orthopaedic Surgery, Chang Gung Memorial Hospital, Chang Gung University, Taipei, Taiwan, ROC.
authors.forename: Wei-Hsiu
authors.initials: WH
authors.lastname: Hsu
authors.forename: Robert Wen-Wei
authors.initials: RW
authors.lastname: Hsu
authors.forename: Tsung-Jen
authors.initials: TJ
authors.lastname: Huang
authors.forename: Kam-Fui
authors.initials: KF
authors.lastname: Lee
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D005260:Female; D005548:Foreign-Body Migration / Q000150:complications* / Q000473:pathology; D015745:Granuloma, Foreign-Body / Q000150:complications* / Q000209:etiology / Q000473:pathology; D006801:Humans; D011151:Popliteal Cyst / Q000209:etiology* / Q000601:surgery; D011475:Prosthesis Failure; D012086:Reoperation