title: Does an Anterior-Lipped Tibial Insert Adequately Substitute for a Post-Cam Articulation in Total Knee Arthroplasty.
abstract: BACKGROUND
  Newer tibial inserts with enhanced conformity (cruciate stabilizing anterior lip; CS) to obviate the need for a posteriorly stabilized (PS) post-cam articulation in posterior cruciate ligament-deficient knees have been recently introduced in modern total knee arthroplasty (TKA). The purpose of this study was to evaluate whether clinical and functional outcomes differ in TKA cohorts without a posterior cruciate ligament (PCL) utilizing either CS anterior-lipped or PS post-cam articulation.
  
  
  METHODS
  Prospectively collected outcomes were compared in matched cohorts of modern TKAs implanted with either CS anterior-lipped tibial inserts or PS post-cam articulations. The PCL was resected in all knees. Modern Knee Society Scores (objective, function, and satisfaction scores), walking and stair pain, EuroQol five dimensions (EQ-5D) health-related quality of life, and UCLA activity level were assessed at minimum one-year follow-up.
  
  
  RESULTS
  Forty-three anterior-lipped and 39 PS TKAs were matched on sex, age, BMI, and ASA classification at the time of surgery and months of follow-up. CS knees had significantly higher preoperative function scores than PS knees (p = 0.033), but both groups had equivalent function scores at minimum follow-up of one-year (p = 0.687). Eight-one percent of patients in each group reported being satisfied or very satisfied with their TKA (X2 = 0.072, p = 0.964).
  
  
  CONCLUSIONS
  This study supports the hypothesis that an anterior-lipped insert is an adequate functional substitute for a post-cam articulation in patients undergoing TKA with PCL excision. These findings suggest that a PS post-cam articulation may not be necessary given the introduction, availability, and clinical performance of anterior-lipped and more conforming tibial bearings. Further study and longer term follow-up is warranted.
authors.affiliation: Orthopedic One, Upper Arlington, Ohio.
authors.forename: Rahul K
authors.initials: RK
authors.lastname: Biyani
authors.affiliation: Indiana University Health Physicians Orthopedics and Sports Medicine, IU Health Saxony Hospital, Fishers, Indiana.
authors.forename: Mary
authors.initials: M
authors.lastname: Ziemba-Davis
authors.affiliation: Indiana University Health Physicians Orthopedics and Sports Medicine, IU Health Saxony Hospital, Fishers, Indiana, Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, Indiana.
authors.forename: Philip H
authors.initials: PH
authors.lastname: Ireland
authors.affiliation: Indiana University Health Physicians Orthopedics and Sports Medicine, IU Health Saxony Hospital, Fishers, Indiana, Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, Indiana.
authors.forename: R Michael
authors.initials: RM
authors.lastname: Meneghini
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods; D006801:Humans; D007720:Knee Prosthesis / Q000009:adverse effects / Q000706:statistics & numerical data; D017060:Patient Satisfaction / Q000706:statistics & numerical data; D011788:Quality of Life; D016059:Range of Motion, Articular; D013977:Tibia / Q000601:surgery*; D016896:Treatment Outcome