Study of Knee Replacements for Patellofemoral Osteoarthritis (PFA/TKR)

• Patient-reported outcomes (disease-specific and generic QoL instruments) [ Time Frame: 10 years ] [ Designated as safety issue: Yes ]
  Patient reported outcomes are the primary outcomes of the study. These include general QoL measures (SF-36 and EQ5D) and disease specific outcome measures (Oxford Knee Score, KOOS, Kujala).
  
  

• Implant survival, clinician assessment and cost. [ Time Frame: 10 years ] [ Designated as safety issue: Yes ]
  Secondary outcome measures relate to implant survival, clinician assessment and cost. Implant survival will be assessed by 5- and 10-year implant survival rates and by analyzing causes for revision surgery. Clinician assessment includes Knee Society Score (stability, range of movement, effusion, tenderness etc.). Assessments of immediate and long-term costs are based on patient diaries, sick leave, use of medical services and drug prescriptions.
  
  

Isolated patellofemoral osteoarthritis can be a disabling condition of the knee necessitating knee arthroplasty. It is debated whether total knee replacement or isolated patellofemoral replacement is the better treatment option. This randomized trial attempts to give a qualified answer to the debate by comparing clinical outcome (range of movement, stability, effusion, patellofemoral tracking, tenderness, stair climbing), patient self assessment scores (EQ-5D, Oxford Knee Score, KOOS, SF-36, AKS), complications (infections, revisions), longevity (survival analysis) and cost (direct and indirect) for the two implant types.

The Avon patellofemoral implant has been chosen, as this is the patellofemoral implant with the best documentation. The PFC Sigma CR total knee implant has been chosen as it a current standard implant and market leader.