Adolescent knee pain and patellar dislocations are associated with patellofemoral osteoarthritis in adulthood: A case control study

BackgroundThere is a lack of information about the association between patellofemoral osteoarthritis (PFOA) and both adolescent anterior knee pain (AKP) and previous patellar dislocations.MethodsThis case-control study involved 222 participants from our knee arthroplasty database answering a questionnaire. One hundred and eleven patients suffering from PFOA were 1:1 matched by gender with a unicompartmental tibiofemoral arthritis control group. Multivariate correlation and binary logistic regression analysis were performed, with odds ratios (ORs) and 95% confidence intervals (CIs) calculated.ResultsAn individual is 7.5 times more likely to develop PFOA if they have suffered from adolescent AKP (OR 7.5, 95% CIs 1.51 to 36.94). Additionally, experiencing a patellar dislocation increases the likelihood of development of PFOA, with an adjusted odds ratio of 3.2 (95% CIs 1.25 to 8.18). A 44-year difference in median age of first dislocation was also observed between the groups.ConclusionThis should bring into question the traditional belief that adolescent anterior knee pain is a benign pathology. Patellar dislocation is also a significant risk factor. These patients merit investigation, we encourage clinical acknowledgement of the potential consequences when encountering patients suffering from anterior knee pain or patellar dislocation.