title: Early instability with mobile-bearing total knee arthroplasty: a series of 25 cases.
abstract: Between December 1987 and January 2002, 25 cases of clinical instability following mobile-bearing total knee arthroplasty (TKA) with meniscal bearings or rotating platforms presented for evaluation at our institution. These cases were retrospectively identified. All were performed at outside institutions by a variety of surgeons. All clinical examinations were performed by the authors. Nine cases were revised at our institution. All 25 cases had clinical evidence of severe coronal-plane instability and pain. Eight cases had polyethylene dislocation or subluxation that was evident radiographically and clinically. Four cases had extensor-mechanism dysfunction. Eighteen cases had symptoms immediately postoperatively. Twenty-three of the 25 cases had symptoms within 2 years' postoperatively. Any potential long-term benefit of design innovations must be balanced with known problems leading to early failure.
authors.affiliation: Roanoke Orthopaedic Center, Roanoke, Virginia 24018, USA.
authors.forename: Stephen
authors.initials: S
authors.lastname: Ridgeway
authors.forename: Joseph T
authors.initials: JT
authors.lastname: Moskal
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000209:etiology*; D007719:Knee Joint; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D011475:Prosthesis Failure; D016059:Range of Motion, Articular; D012086:Reoperation; D012189:Retrospective Studies; D016896:Treatment Outcome; D016474:Weight-Bearing