title: A locked knee in extension: a complication of a degenerate knee with patella alta.
abstract: We present a case of superior dislocation of the patella trapped by interlocked osteophytes. Unlike previous reports, in which the mechanism resulted from a blow to the inferior pole, it is postulated that increased load on the extensor mechanism, combined with patella alta and patellofemoral osteophytes, caused locking of the knee in extension.
authors.affiliation: Pontefract General Infirmary, West Yorkshire, England.
authors.forename: T G
authors.initials: TG
authors.lastname: McWilliams
authors.forename: M S
authors.initials: MS
authors.lastname: Binns
mesh_terms: D000062:Accidents, Occupational; D000328:Adult; D006801:Humans; D004204:Joint Dislocations / Q000000981:diagnostic imaging* / Q000209:etiology* / Q000503:physiopathology / Q000601:surgery; D007594:Joint Loose Bodies / Q000150:complications* / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D017770:Lifting / Q000009:adverse effects; D008297:Male; D008349:Manipulation, Orthopedic; D010329:Patella / Q000293:injuries*; D011859:Radiography; D016059:Range of Motion, Articular; D016474:Weight-Bearing