title: Ten-Year Results of Primary and Revision Condylar-Constrained Total Knee Arthroplasty in Patients with Severe Coronal Plane Instability.
abstract: OBJECTIVE
  To retrospectively review the results at minimum ten years after surgery of a consecutive series of total knee arthroplasties (TKAs) performed using a constrained condylar implant in patients with severe coronal plane instability.
  
  
  METHODS
  The series comprised of 44 patients (45 knees) who received primary (19 knees) or revision (26 knees) TKA with a constrained condylar implant between 2001 and 2003 at a single institution.
  
  
  RESULTS
  There were no revisions or any other surgery related complications at a mean implantation time of 11.0 years. In 38 patients (15 knees in the primary group and 24 knees in the revision group) who were available for clinico-radiographic follow-up at a minimum of ten years, there was no sign of radiographic loosening. Two patients showed cortical hypertrophy at the extension stem tip but none complained of pain around the stem tip. According to the TLKSS score grading, 73% of the patients in the primary group had results categorized as good or excellent, while 54% of the patients in the revision group had fair results. Four patients (one (7%) in the primary group and three (13%) in the revision group) had poor results. The median WOMAC Index was 80.2% (interquartile range: 74.0% - 81.2%) and 74.0% (interquartile range: 72.1% - 75.8%) in the primary and in the revision groups, respectively (p=0.010).
  
  
  CONCLUSIONS
  This study showed satisfactory clinical outcomes with no re-operations at minimum ten years after implantation in patients who had undergone primary or revision TKA with a condylar constrained implant.
authors.affiliation: Department of Prosthetic Surgery, Santa Corona Hospital, via XXV Aprile 38, 17027 Pietra Ligure (SV), Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Camera
authors.affiliation: Department of Prosthetic Surgery, Santa Corona Hospital, via XXV Aprile 38, 17027 Pietra Ligure (SV), Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Biggi
authors.affiliation: Department of Prosthetic Surgery, Santa Corona Hospital, via XXV Aprile 38, 17027 Pietra Ligure (SV), Italy.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Cattaneo
authors.affiliation: Clinical Affairs Department, Zimmer GmbH, Winterthur, Switzerland.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Brusaferri
keywords: Condylar constrain; Coronal plane instability; Primary total knee arthroplasty; Revision total knee arthroplasty; TLKSS; Varus-valgus constrain; WOMAC