This review systematically summarises factors associated with patellofemoral pain syndrome (PFPS). A systematic literature search was conducted. Studies including ≥20 patients with PFPS that examined ≥1 possible factor associated with PFPS were included. A meta-analysis was performed, clinical heterogeneous data were analysed descriptively. The 47 included studies examined 523 variables, eight were pooled. Pooled data showed a larger Q-angle, sulcus angle and patellar tilt angle (weighted mean differences (WMD) 2.08; 95% CI 0.64, 3.63 and 1.66; 95% CI 0.44, 2.77 and 4.34; 95% CI 1.16 to 7.52, respectively), less hip abduction strength, lower knee extension peak torque and less hip external rotation strength (WMD -3.30; 95% CI -5.60, -1.00 and -37.47; 95% CI -71.75, -3.20 and -1.43; 95% CI -2.71 to -0.16, respectively) in PFPS patients compared to controls. Foot arch height index and congruence angle were not associated with PFPS. Six out of eight pooled variables are associated with PFPS, other factors associated with PFPS were based on single studies. Further research is required.

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...

More than half of participants with PFP reported an unfavourable recovery 5-8 years after recruitment, but did not have radiographic knee OA. Longer PFP duration and worse AKPS score at baseline predict poor PFP prognosis. Education of health practitioners and the general public will provide patients with more realistic expectations regarding prognosis.

Analysis 4.1. Comparison 4 Delivery of exercise: supervised versus home exercise programme, Outcome 1 Usual pain