title: Intra-articular giant synovial osteochondroma: case reports of the ankle and knee joint.
abstract: Two cases of giant intra-articular osteochondromas (knee and ankle joint) are reported; pathologically they are rare representations of synovial chondromatosis. A 17-year-old man presented with a tumorous mass which had been localized in his left ankle for many years, increasing in volume during the last months. The lesion was removed by posteromedial ankle arthrotomy. The second case was observed in a 39-year-old woman with a slow-growing mass in her right knee joint. The lesion was removed from the Hoffa fat pad by open anteromedial arthrotomy.
authors.affiliation: Clinic of Orthopedic Surgery, Fribourg Cantonal Hospital, Chemin des Pensionnats 2-6, 1708 Fribourg, Switzerland.
authors.forename: Paolo
authors.initials: P
authors.lastname: Fornaciari
authors.affiliation: Clinic of Orthopedic Surgery, Wolhusen Cantonal Hospital (LUKS), P.O. Box 365, 6110 Wolhusen, Switzerland.
authors.forename: Pascal A
authors.initials: PA
authors.lastname: Schai
authors.affiliation: Clinic of General Surgery, Uri Cantonal Hospital, Spitalstrasse 1, 6460 Altdorf, Switzerland.
authors.forename: Richard
authors.initials: R
authors.lastname: Niehaus
authors.affiliation: Orthopedic Center Zurich (OZZ), Seestrasse 259, 8038 Zurich, Switzerland.
authors.forename: Ulrich G
authors.initials: UG
authors.lastname: Exner