Patellar Dislocation in Youth May Pose a Risk for Dislocation Later in Life

    Young patients who suffer patellar dislocations are at a higher risk of recurring dislocations, even years after their initial injury, according to research presented at the American Orthopaedic Society for Sports Medicine’s Annual Meeting in Toronto, Ontario, Canada.

    The research was honored with the Herodicus Award, presented to the best resident paper featured at the meeting as determined by the Herodicus Society.

    “Our research showed that within the study group, 104 patients had ipsilateral recurrent patellar dislocation, with over 20% of cases occurring in the first 2 years following the initial injury,” said lead author Thomas L. Sanders, MD, from Mayo Clinic.

    “By 15 and 20 years, this number had reached 54% of patients – a concerning rate of recurrence.”

    The study included 232 skeletally immature patients, defined as such if their proximal tibia and distal femoral physes were open at the time of dislocation, who experienced a first-time lateral patellar dislocation between 1990 and 2010.

    Patients were followed for a mean of 12.1 years to determine cumulative rates of subsequent dislocations and clinically significant patellofemoral arthritis.

    • Dislocations: 11% at 1 year, 21.1% at 2 years, 37.0% at 5 years, 45.1% at 10 years, 54.0 % at 15 years, and 54.0% at 20 years
    • Patellofemoral arthritis: % at 2 years, 1.0% at 5 years,2.0% at 10 years, 10.1% at 15 years, 17%% at 20 years, and 39.0% at 25 years

    “Despite high numbers of recurrence, our research showed that these young patients did not develop significant patellofemoral arthritis,” Dr. Sanders said.

    “We hope to use our research to help educate both physicians and parents on the risks young athletes face after these injuries in their early years, and hopefully take steps to prevent them.”

    The study adds to previous studies that typically show 40% of adolescent patients go on to experience a recurring patellar dislocation.


    Sanders TL, Pareek A, Hewett TE, Stuart MJ, Dahm DL, Krych AJ. What is the Natural History of Patellar Dislocation in Skeletally Immature Patients? (paper 104). Presented at the Annual Meeting of the American Orthopaedic Society for Sports Medicine, July 20-23, 2017, Toronto, Ontario, Canada. All abstracts from the meeting can be found here.