A systematic review of reviews on patellofemoral pain syndrome. Exploring the risk factors, diagnostic tests, outcome measurements and exercise treatment

Abstract: Background: Literature has shown a growing number of published studies on Patellofemoral Pain Syndrome
every year. The increasing evidence base has revealed a significant number of reviews which makes it confusing for
clinicians and researchers to choose from the best evidence. This study aimed to gather the reviews on Patellofemoral Pain
Syndrome and provide information about the most common clinical tests, risk factors, exercise treatment and outcome
measures. In addition, secondary questions aimed to report the study settings and patient characteristics of the primary
included studies.
Methods: Studies eligible for this Review of Reviews were those published from 1993 to July 2013. Databases searched
included PubMed, CINAHL, SPORTDiscus, Pedro and the Cochrane Library. Four key areas were searched using the
words: PFPS, Anterior Knee Pain (AKP) or Chondromalacia patella (CP), plus a keyword. The keywords for the four
research topics were a) risk factors; b) exercise treatment; c) diagnostic clinical tests and d) psychometric outcome
measurements. Only reviews with clear methodological strategy were included. A two-stage evaluation was performed ineach review assessment. At first, the level of evidence was graded and then the methodological quality of each review was
assessed.
Results: Full text screening revealed that only 18 reviews were eligible for use. The selected reviews included 213 primary
studies. After excluding duplicates, 144 primary studies were screened to answer the secondary questions. A gold standard
clinical test for PFPS assessment cannot be reached and the use of functional tasks should be considered. The quadriceps
strength deficits are still the only evidence based risk factors along with the dynamic malalignment of the lower limb.
More research is still required on strength and flexibility deficits of other lower limb muscles. The quadriceps-based
exercises are still the only ones to have strong evidence together with hamstrings, quadriceps, gastrocnemius and anterior
hip muscles stretching. Finally, the usage of Activities of Daily Living Scale is recommended as the best outcome
measure.
Conclusion: There is no evidence on whether the above treatment and assessment methods should be used in sedentarypeople or differently across population groups or gender. More RCTs with large populations, powered correctly, inclinical environments are called for in further research.

© Papadopoulos et al.; Licensee Bentham Open.
This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/)
which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.