Risk Factors for Patellofemoral Pain Syndrome: A Systematic Review

Abstract

Patellofemoral pain syndrome (PFPS) is the most frequently diagnosed condition in patients younger than 50 years with knee complaints. While the general practitioner sees an average of 5 or 6 new patients with PFPS per year , the incidence of PFPS in the general population is still unknown. 4,37 Women have a higher incidence of PFPS than men, 33 and incidence rates of 25% to 43% have been reported in sports medicine and during basic military T T STUDY DESIGN: Systematic review. T T OBJECTIVES:To systematically outline the risk factors for patellofemoral pain syndrome (PFPS). T T BACKGROUND:PFPS is the most commonly diagnosed condition in young individuals with knee complaints. High incidence among athletes suggests a possibility of prevention. The first step toward prevention is identification of possible risk factors. T T METHODS:Prospective studies that included 20 or more patients with PFPS and examined at least 1 possible risk factor for PFPS were included. An assessment list was applied to evaluate the quality of the studies. A meta-analysis was conducted using a random-effects model. Significant differences were based on calculated mean differences, with matching 95% confidence intervals (CIs). For dichotomous data, odds ratios or relative risks were calculated. T T RESULTS:Of the 3845 potentially relevant articles, 7 were included in this review. These studies examined a total of 135 variables, and pooling was possible for 13 potential risk factors. The pooled data showed that knee extension peak torques were significantly lower in the PFPS group than in controls. Mean differences in torque, with negative differences reflecting lower means in the PFPS group, were as follows: (a) standardized relative to body weight at 60°/s, -0.24 Nm (95% CI: -0.39, -0.09); (b) standardized relative to body weight at 240°/s, -0.11 Nm (95% CI: -0.17, -0.05); (c) standardized relative to body mass index at 60°/s, -0.84 Nm (95% CI: -1.23, -0.44); (d) standardized relative to body mass index at 240°/s, -0.32 Nm (95% CI: -0.52, -0.12); (e) nonstandardized in a concentric mode at 60°/s, -17.54 Nm (95% CI: -25.53, -9.54); (f) nonstandardized in a concentric mode at 240°/s, -7.72 Nm (95% CI: -12.67, -2.77). T T CONCLUSION:Weaker knee extension strength, expressed by peak torque, appears to be a risk factor for PFPS, based on meta-analyses of pooled results from multiple studies. Because several other risk factors for PFPS were described only in single studies, these additional risk factors, as well as those with conflicting evidence, need to be confirmed in future studies. Prognosis, level 1a-. J Orthop Sports Phys Ther 2012;42(2):81-94, Epub 25 October 2011. doi:10.2519/jospt.2012 14,34 T T LEVEL OF EVIDENCE:The term patellofemoral pain syndrome is commonly used to describe a condition of anterior knee pain. Although there is no consensus on the terminology, various synonyms are used for PFPS. 12 The guidelines of the Dutch College of General Practitioners describe PFPS as a pain in or around the patella. This pain increas...

Validity of measuring distal vastus medialis muscle using rehabilitative ultrasound imaging versus magnetic resonance imaging

“…An example is vastus medialis, where substantial alterations in fibre alignment are seen between proximal and distal muscle portions (Smith et al , 2009). The distal oblique fibres are thought to play a pivotal role in the kinematics and alignment at the patellofemoral joint (Berry et al , 2008, Fagan and Delahunt, 2008, Lin et al , 2008 and physiological or biomechanical dysfunction of this muscle are reported to contribute to patellofemoral pain (PFP) (Lankhorst et al , 2012). Recent research has used RUSI to assess the pennation angle of these oblique muscle fibres in cadaveric specimens (Engelina et al , 2012) and assess muscle volume in individuals with PFP (Lin, Lin, 2008, Jan et al , 2009.…”

A Systematic Review of Reviews in Patellofemoral Pain Syndrome. Exploring the Risk Factors, Diagnostic Tests, Outcome Measurements and Exercise Treatment

“…No level of evidence was reported for the four reviews which were not systematic or meta-analysis. The results showed two clinical test reviews of high quality systematic reviews of case control or cohort studies [34,35], one high quality meta-analysis of RCT's [36] and three high quality systematic reviews of case control or cohort studies on risk factors [9,17,37], three high quality meta-analyses or systematic reviews of RCT's [11,38,39] and three high quality systematic reviews of case control or cohort studies on exercise treatment [12,13,40] and two high quality systematic reviews of case control or cohort studies on outcome measures [41,42].…”

“…The reason was that this study reported to have a priori design (AMSTAR question-1, PRISMA checklist item-5). On the opposite side, the two studies from Lankhorst et al [9,36] were the only studies which assessed the likelihood of publication bias (AMSTAR Question-10, PRISMA checklist item-15). All studies performed a comprehensive literature search (question 3 AMSTAR) which was anticipated because this criterion was one of the inclusion criteria for the current review.…”

Influence of the treatment of the Kinesio-taping® technique on pain and functionality in patients with Patellofemoral Pain Syndrome

“…This imbalance is considered the main factor for the appearance of the symptoms, which changes the patellar kinematics and contributes to the increase of the patellofemoral reaction and The decreased strength of the quadriceps, the main dynamic stabilizer of the patella in the femoral trochlea, is directly related to the incidence of patellar-femoral pain and plays an important role in the onset of PFPS. Therefore, it is pointed out as a risk factor, which was also concluded in a recent systematic review 6 . For patients diagnosed with PFPS, conservative treatment is always considered as the first and best option.…”