Purpose/background: Anterior knee pain (AKP), also known as patellofemoral pain syndrome (PFPS), is believed to be common in young, active females. A prevalence rate of 25% has been commonly cited in the literature. However, this rate may be more anecdotal than empirical. The purpose of this study was to estimate the prevalence of AKP in females 18 to 35 years of age.
Methods: Three cohorts of females, totaling 724 participants between 18 and 35 years of age participated in this study. The mean age of participants was 24.17 years (SD: 2.34), mean height was 165.10 cm (SD: 7.26), mean weight was 65.46 kg (SD: 14.10), and mean BMI was 23.95 kg/m2 (SD: 4.86). Participants completed the Anterior Knee Pain Questionnaire (AKPQ), a functional outcome tool developed to document symptoms of AKP and progress in patients during rehabilitation.
Results: The mean score on the AKPQ for the left lower extremity was 93.38 (SD: 10.00) and 93.16 (SD: 11.37) for the right lower extremity. Using a cutoff score of 83 on the AKPQ, 85 of 724 subjects were classified as having AKP in the left lower extremity for a prevalence of 12% (95% CI = 9%-14%) while 94 subjects were classified with AKP in the right lower extremity for a prevalence of 13% (95% CI = 11%-15%).
Conclusion: The estimated prevalence of AKP in this sample of 18-35 year old females of 12-13% is much less than the commonly cited value of 25%. The results may provide a better representation of subjects with AKP.
Level of evidence: 3.
Keywords: Anterior Knee Pain Questionnaire (AKPQ); Anterior knee pain; functional limitations; prevalence.