title: Unicompartmental knee replacement: Does the macroscopic status of the anterior cruciate ligament affect outcome?
abstract: OBJECTIVE
  ACL damage is associated with progression of arthritis and whilst in the population undergoing joint replacement in the majority of cases the ACL is intact there is a wide spectrum of ACL disease. This study investigated whether the macroscopic status of the ACL affected functional outcome or survival following UKR.
  
  
  METHODS
  The macroscopic status of the ACL was recorded in 820 cemented Oxford UKRs implanted by two surgeons for the recommended indications. The ACL was considered functionally normal in the setting of anteromedial tibial wear and macroscopically the ACL visually appeared normal or had synovial damage or longitudinal splits. The patients were followed up independently with a mean follow-up of 10.3years (range 5.3 to 16.6).
  
  
  RESULTS
  More marked ACL macroscopic damage was significantly associated with increasing age, male gender and a more extensive anteromedial tibial defect. Patients with more ACL damage had a significantly lower pre-operative AKSS Objective Score, however no difference in AKSS-Functional or OKS was detected between groups. At 10years no difference in functional outcome or activity level was found between groups. Compared to those with a macroscopically normal ACL at 10years a significantly greater improvement from baseline OKS score was seen in patients with macroscopic ACL abnormalities. At 15years no difference in implant survival, or failure mechanism, was detected between groups.
  
  
  CONCLUSIONS
  The macroscopic status of the ACL does not affect long term functional outcomes or implant survival and in the setting of an intact ACL macroscopic status is not a contraindication to mobile bearing UKR.
  
  
  METHODS
  Level IV.
authors.affiliation: Nuffield Department of Orthopaedics, Rheumatology, Musculoskeletal Sciences, University of Oxford, Windmill Road, Oxford, UK. Electronic address: thomas.hamilton@ndorms.ox.ac.uk.
authors.forename: T W
authors.initials: TW
authors.lastname: Hamilton
authors.affiliation: Nuffield Orthopaedic Centre, Oxford University Hospitals NHS Foundation Trust, Windmill Road, Oxford, UK.
authors.forename: C
authors.initials: C
authors.lastname: Pistritto
authors.affiliation: Nuffield Orthopaedic Centre, Oxford University Hospitals NHS Foundation Trust, Windmill Road, Oxford, UK.
authors.forename: C
authors.initials: C
authors.lastname: Jenkins
authors.affiliation: Nuffield Department of Orthopaedics, Rheumatology, Musculoskeletal Sciences, University of Oxford, Windmill Road, Oxford, UK.
authors.forename: S J
authors.initials: SJ
authors.lastname: Mellon
authors.affiliation: Nuffield Orthopaedic Centre, Oxford University Hospitals NHS Foundation Trust, Windmill Road, Oxford, UK.
authors.forename: C A F
authors.initials: CA
authors.lastname: Dodd
authors.affiliation: Nuffield Department of Orthopaedics, Rheumatology, Musculoskeletal Sciences, University of Oxford, Windmill Road, Oxford, UK; Nuffield Orthopaedic Centre, Oxford University Hospitals NHS Foundation Trust, Windmill Road, Oxford, UK.
authors.forename: H G
authors.initials: HG
authors.lastname: Pandit
authors.affiliation: Nuffield Department of Orthopaedics, Rheumatology, Musculoskeletal Sciences, University of Oxford, Windmill Road, Oxford, UK; Nuffield Orthopaedic Centre, Oxford University Hospitals NHS Foundation Trust, Windmill Road, Oxford, UK.
authors.forename: D W
authors.initials: DW
authors.lastname: Murray
mesh_terms: D000368:Aged; D016118:Anterior Cruciate Ligament / Q000473:pathology*; D019645:Arthroplasty, Replacement, Knee; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000473:pathology* / Q000601:surgery*
keywords: Anterior cruciate ligament; Functional outcome; Implant survival; Unicompartmental knee replacement