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Comparative Effectiveness Review of Patellofemoral Arthroplasty for Isolated Osteoarthritis of the Knee

November 27, 2018

Health Problem: Osteoarthritis (OA) refers to the destruction of cartilage, the protective covering overlying bones at joints such as the knee or hip. Isolated patellofemoral OA (PFOA) involves only the junction between the kneecap (patella) and the distal thighbone (femur). PFOA is caused by trauma, malalignment of the joint, age-related degeneration, congenital trochlear dysplasia, and other factors. Symptoms of PFOA may include pain, swelling, inflammation, muscle weakness, impaired quality of life, and reduced function. In a symptom-based cohort, the prevalence of isolated PFOA was 8% compared with 27% of individuals with combined PFOA and tibiofemoral OA.

Technology Description: Patellofemoral arthroplasty (PFA) involves the implantation of a prosthesis to resurface the articulating surfaces of the patella and femur. PFA is less invasive than total knee arthroplasty (TKA) with advantages, including less blood loss and faster recovery for most patients. Prior to implantation, the alignment, tracking, and articular cartilage surfaces of the joint are assessed by imaging tests, and a concerted effort is made to identify the presence of tibiofemoral joint degeneration and patellar malalignment since these may preclude successful PFA. Following resection of the articulating surface, an orthopedic surgeon implants the prosthesis with or without bone cement during an inpatient procedure using general or spinal anesthesia. Currently, there are numerous PFA implants on the market and computer-designed custom implants are also available.

Controversy: PFA has been available for many years; however, early design failure rates prevented its widespread acceptance. In recent years, advances in PFA technique and design of prostheses has renewed interest in the procedure

Key Questions:

  • How does PFA compare with TKA for improving pain and function in patients with isolated PFOA?
  • How does PFA compare with TKA with respect to safety in patients with isolated PFOA?
  • How do different PFA implant designs compare with each other for treatment of patients with isolated PFOA of the knee?
  • Have definitive patient selection criteria for PFA for isolated PFOA been established?