title: Increased Risk of Postoperative Complications After Total Knee Arthroplasty in Patients With Previous Patellectomy.
abstract: Few studies have reported the results of total knee arthroplasty (TKA) in patients with previous patellectomy. The purpose of this study was to assess the risk of complications and survivorship of primary TKA in patients who previously had a patellectomy in comparison to those undergoing TKA with patellar resurfacing.
  
  
  
  This was a historical cohort study and comprised 134 knees with previous patellectomy in a cohort of 17,946 primary TKA procedures at a single institution between 1985 and 2010. Multivariable Cox regression analyses were used to estimate the risk of complications and revisions in patients with previous patellectomy.
  
  
  
  When compared to TKA with patellar resurfacing, the risk of complications (hazards ratio: 1.38, 95% confidence interval: 1.05, 1.81) was significantly higher in post-patellectomy knees, but there was no difference in the risk of revisions (hazards ratio: 1.32, 95% confidence interval: 0.80, 2.18). There was no significant difference between the posterior-stabilized and cruciate-retaining designs in terms of both complications and revisions (P > .05). The most common complications in post-patellectomy knees were instability, delayed healing, and infection.
  
  
  
  TKA patients with previous patellectomy have a higher risk of complications but not a higher risk of revisions.
authors.affiliation: Mayo Medical School, Mayo Clinic, Rochester, Minnesota.
authors.forename: Omar J
authors.initials: OJ
authors.lastname: Haque
authors.affiliation: Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota; Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota.
authors.forename: Hilal
authors.initials: H
authors.lastname: Maradit Kremers
authors.affiliation: Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota.
authors.forename: Walter K
authors.initials: WK
authors.lastname: Kremers
authors.affiliation: Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Berry
authors.affiliation: Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota.
authors.forename: David G
authors.initials: DG
authors.lastname: Lewallen
authors.affiliation: Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota.
authors.forename: Robert T
authors.initials: RT
authors.lastname: Trousdale
authors.affiliation: Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota.
authors.forename: Rafael J
authors.initials: RJ
authors.lastname: Sierra
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D010329:Patella / Q000601:surgery*; D011183:Postoperative Complications / Q000453:epidemiology* / Q000209:etiology; D016016:Proportional Hazards Models; D012044:Regression Analysis; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors
keywords: TKA; complications; patella; patellectomy; revision; total knee arthroplasty