Patellofemoral arthroplasty

Purpose of review: Prosthetic replacement of the patella and femoral trochlea has existed since the mid 1970s. There have been a handful of studies regarding this topic over the past 30 years, with most having small patient numbers and short-term follow-up. Outcomes have been variable, which has led to poor acceptance of this procedure. Currently, there is renewed interest in patellofemoral arthroplasty (PFA), presumably owing to improvements in component design, better understanding of patient selection, and a desire for less invasive surgery. This review focuses on the recent literature regarding PFA. Recent findings: Short-term studies of newer designs indicate good to excellent results in greater than 90% of cases. A longer-term study demonstrated a 75% survivorship at 11 years. A biomechanical analysis noted that similar tracking patterns to the normal knee are achievable with PFA. One study reported abandonment of an older design owing to poor patient satisfaction and a high rate of mechanical complications. Recent studies have focused on patient selection criteria, design considerations, technical advice, and appropriate use of the procedure. Summary: Success of PFA depends on component design, technique, and patient selection. Recent reports indicate better short-term results with newer designs. Although the use of PFA will probably increase, it will remain a relatively uncommon procedure because of the small proportion of patients meeting the indications. Middle-aged patients with isolated patellofemoral arthritis, intact alignment, and reasonable functional expectations seem the most appropriate candidates. Continued study of this procedure is warranted and should include larger case series, longer-term follow-up, and biomechanical analysis.