Surgical treatment of isolated patellofemoral osteoarthritis.
BACKGROUND
Isolated patellofemoral (PF) osteoarthritis (OA) affects 9% of persons older than 40 years. Nonoperative treatment should be exhausted fully before surgical treatment.


OBJECTIVE
The purpose of this article is to review the literature after 2008 with the aim of answering the following question: Which of the following surgical procedures has the highest survival rate and the lowest revision rate in advanced isolated PF OA: patellofemoral arthroplasty (PFA), total knee arthroplasty (TKA) or lateral facetectomy.


METHODS
The search engine was MedLine. The keywords used were: PF OA and PFA. Three hundred and fifty-three articles were found between 2008 and 25 July 2013. Of those, only 23 were selected and reviewed because they were strictly focused on the topic and the question of this article.


RESULTS
The types of studies reported so far have a low level of evidence (levels III and IV). Most of them are prospective case series (level IV). Some are systematic reviews of level III studies. Reported survival rate of lateral facetectomy is 85% at 5 years, 67% at 10 years and 47% at 20 years. Reported failure rate of lateral facetectomy is 26% at 10 years and 16% at 12 years. The reported average time of reoperation is 8 years and 37% of such procedures fail. Survival rate of PFA has been reported to be 87.5% on average (range, 60-100%). The revision rate of PFA is 20%. Recent improvements in PFA design have resulted in improvements in short-and medium-term results, similar to those of TKA.


CONCLUSIONS
There is still no gold standard for the surgical treatment of isolated PF OA. However, PFA or TKA appear to be the most recommendable treatment in cases that do not respond to conservative treatment.
Department of Orthopaedic Surgery, La Paz University Hospital, Paseo de la Castellana 261, 28046 Madrid, Spain ; School of Medicine, Autónoma University, Madrid, Spain.
E Carlos
EC
Rodriguez-Merchan
isolated; osteoarthritis; patellofemoral joint; surgical treatment