title: Sport and physical activity following unicompartmental knee arthroplasty: a systematic review.
abstract: OBJECTIVE
  Unicompartmental knee arthroplasty (UKA) can be a surgical treatment option for patients with high expectations regarding the post-operative level of physical activity. A systematic review was undertaken to answer three research questions: (1) is there an improvement of physical activity based on validated activity scores following UKA? (2) What are the sport disciplines and the sport patterns of UKA patients? (3) What are the pre- and post-operative sport participation rates and the return to activity rates of UKA patients?
  
  
  METHODS
  Following the PRISMA guidelines, EMBASE, MEDLINE, ISI Web of Science and the Cochrane Central Register of Controlled Trials were searched for studies reporting the level of sport and/or physical activity before and after UKA, and/or included at least one activity score before and after UKA.
  
  
  RESULTS
  Seventeen studies were identified reporting on 2972 UKAs, of which 89 % were medial UKAs and 92 % were mobile-bearing implants, respectively. Ten studies reported a statistically significant improvement of physical activity following UKA according to the UCLA activity score, the Tegner activity score or the High Activity Arthroplasty Score, respectively. Hiking, cycling and swimming are the most common activities following UKA. Sport participation before the onset of restricting symptoms ranged from 64 to 93 % and slightly decreased by 2-9 % following UKA. The return to activity rate ranged from 87 to 98 %.
  
  
  CONCLUSIONS
  Patients following UKA are physically active according to validated activity scores. A significant increase in low-impact activities and a decrease in high-impact activities after UKA was observed. Patients with a UKA regularly participate in sports; however, sport participation slightly decreased compared to pre-arthritic levels. This systematic review helps physicians to manage the expectations of patients regarding the level of physical activity following UKA.
  
  
  METHODS
  III.
authors.affiliation: Department of Orthopaedics, Vienna General Hospital, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria. wwaldstein@gmail.com.
authors.forename: Wenzel
authors.initials: W
authors.lastname: Waldstein
authors.affiliation: Department of Orthopaedics, Vienna General Hospital, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria.
authors.forename: Paul
authors.initials: P
authors.lastname: Kolbitsch
authors.affiliation: Department of Orthopaedics, Vienna General Hospital, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Koller
authors.affiliation: Adult Reconstruction and Joint Replacement Division, Hospital for Special Surgery, New York, NY, USA.
authors.forename: Friedrich
authors.initials: F
authors.lastname: Boettner
authors.affiliation: Department of Orthopaedics, Vienna General Hospital, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Windhager
mesh_terms: D019645:Arthroplasty, Replacement, Knee; D015444:Exercise; D006801:Humans; D065466:Lysholm Knee Score; D020370:Osteoarthritis, Knee / Q000601:surgery; D011184:Postoperative Period; D013177:Sports
keywords: Physical activity; Review; Sport; Unicompartmental knee arthroplasty