title: Survivorship and patient satisfaction of robotic-assisted medial unicompartmental knee arthroplasty at a minimum two-year follow-up.
abstract: BACKGROUND
  Successful clinical outcomes following unicompartmental knee arthroplasty (UKA) depend on lower limb alignment, soft tissue balance and component positioning, which can be difficult to control using manual instrumentation. Although robotic-assisted surgery more reliably controls these surgical factors, studies assessing outcomes of robotic-assisted UKA are lacking. Therefore, a prospective multicenter study was performed to assess outcomes of robotic-assisted UKA.
  
  
  METHODS
  A total of 1007 consecutive patients (1135 knees) underwent robotic-assisted medial UKA surgery from six surgeons at separate institutions between March 2009 and December 2011. All patients received a fixed-bearing metal-backed onlay implant as tibial component. Each patient was contacted at minimum two-year follow-up and asked a series of five questions to determine survivorship and patient satisfaction. Worst-case scenario analysis was performed whereby all patients were considered as revision when they declined participation in the study.
  
  
  RESULTS
  Data was collected for 797 patients (909 knees) with average follow-up of 29.6months (range: 22-52months). At 2.5-years of follow-up, 11 knees were reported as revised, which resulted in a survivorship of 98.8%. Thirty-five patients declined participation in the study yielding a worst-case survivorship of 96.0%. Of all patients without revision, 92% was either very satisfied or satisfied with their knee function.
  
  
  CONCLUSIONS
  In this multicenter study, robotic-assisted UKA was found to have high survivorship and satisfaction rate at short-term follow-up. Prospective comparison studies with longer follow-up are necessary in order to compare survivorship and satisfaction rates of robotic-assisted UKA to conventional UKA and total knee arthroplasty.
authors.affiliation: Hospital for Special Surgery, 535 East 70th St, New York, NY 10021, USA. Electronic address: pearlea@hss.edu.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Pearle
authors.affiliation: Hospital for Special Surgery, 535 East 70th St, New York, NY 10021, USA. Electronic address: vanderlistj@hss.edu.
authors.forename: Jelle P
authors.initials: JP
authors.lastname: van der List
authors.affiliation: Hospital for Special Surgery, 535 East 70th St, New York, NY 10021, USA. Electronic address: leel@hss.edu.
authors.forename: Lily
authors.initials: L
authors.lastname: Lee
authors.affiliation: Coon Joint Replacement Institute, 6 Woodland Road 202, St. Helena, CA 94574, USA. Electronic address: tcoon@osiresearch.com.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Coon
authors.affiliation: Legacy Salmon Creek Hospital, 2211 NE 139th Street, Vancouver, WA 98686, USA. Electronic address: toddborus@yahoo.com.
authors.forename: Todd A
authors.initials: TA
authors.lastname: Borus
authors.affiliation: Holy Cross Hospital, 103 SE 1st Ave, Fort Lauderdale, FL 33316, USA. Electronic address: Martin.roche@holy-cross.com.
authors.forename: Martin W
authors.initials: MW
authors.lastname: Roche
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000601:surgery*; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery*; D017060:Patient Satisfaction; D011446:Prospective Studies; D011475:Prosthesis Failure; D065287:Robotic Surgical Procedures
keywords: Robot; Robotic; Satisfaction; Survivorship; UKA; Unicompartmental knee arthroplasty