Characteristics and Outcome of Patellofemoral Pain in Adolescents: Do They Differ From Adults?

Abstract

Study Design Case series with 1-year follow-up. Background Most of the recommendations for the diagnosis, treatment, and prognosis of patellofemoral pain (PFP) are based on research performed in adults. The literature suggests that there are potential differences between adolescents and adults with PFP. Objectives To investigate differences in characteristics, symptoms, and prognosis at 1-year follow-up between adolescents and adults with PFP. Methods Data from 64 patients with PFP, assessed at baseline and 1-year follow-up, were used. At baseline, data on demographics, symptoms, and coping strategies were obtained by questionnaire. Physical examination included strength and flexibility measurements of the quadriceps and hamstrings. At 1-year follow-up, a questionnaire was used to collect data on pain, function, and recovery. Differences between adolescents (14-18 years) and adults (18-40 years) were analyzed using regression techniques, adjusted for sex, body mass index, and the presence of bilateral pain. Results Of the 64 patients with PFP included at baseline, 78.1% were available for follow-up. At baseline, adolescents with PFP had a significantly lower body mass index (20.7 versus 24.9 kg/m²) and a greater percentage of bilateral pain (70% versus 43.2%) than adults with PFP. There were no differences in reported pain and symptoms between the 2 groups. In total, 25% of the adolescents regarded themselves as recovered after 1 year, compared to 22.7% of the adults (adjusted P = .725). Conclusion The sample size of the study, in relation to the number of statistical tests performed, urges caution in the interpretation of the results. In contrast to what has been suggested previously, only minor differences seem to exist between adolescents and adults with PFP. In both groups, PFP is clearly not a self-limiting disease, with nearly 75% of those in this study reporting persistent pain at 1-year follow-up. Level of Evidence Prognosis, level 4. J Orthop Sports Phys Ther 2017;47(10):801-805. Epub 4 Sep 2017. doi:10.2519/jospt.2017.7326.

Keywords: anterior knee pain; epidemiology; knee; pediatrics.