Research Summary

The prevalence of radiographic and MRI-defined patellofemoral osteoarthritis and structural pathology

Hart, H.F., Stefanik, J.J., Wyndow, N., et al. (2017) B. J. Sports Med. 51(16): 1195-1208.

Key Findings



of patients with radiographic and symptomatic knee OA had PF OA.



of patients with knee pain or symptomatic knee OA had radiographic PF OA.



of patients with knee pain had MRI-defined PF structural damage based on cartilage defect.

To understand the prevalence of patellofemoral osteoarthritis (PF OA) among knee OA patients and sufferers of knee pain, a systematic review and meta-analysis of literature reporting PF OA prevalence was conducted. Literature of interest included accounts of radiographic PF OA and MRI-defined PF structural damage. At the time of the study, there was no accepted definition of PF OA based on MRI. To pool data from MRI populations, the study used several terms pertaining to cartilage defect and bone marrow lesions to indicate the presence of PF structural damage.

An analysis of 85 studies revealed that PF OA is prevalent in a wide range of settings, including symptomatic and asymptomatic populations. Around one half of people with knee pain or radiographic knee OA have PF involvement. MRI-defined PF structural damage was calculated for four populations: community, knee pain or symptomatic, radiographic OA, and healthy individuals. For both community and knee pain or symptomatic populations, MRI-defined PF structural damage based on cartilage defect was present in around half of the cases.

Relevance to Spring Loaded Braces

The high prevalence of PF OA among knee pain sufferers and patients with knee OA underscores the importance of knee pain treatments that target pain originating in the PF compartment. Common braces for knee OA include valgus braces that redistribute forces across the tibiofemoral compartments, but these braces do not sufficiently address pain caused by PF OA. Due to its ability to offload joint forces from all three compartments 1– Budarick, A.R. et al. (2020). J. Biomech. Eng. 142(1)
– McGibbon, C.A. et al. 2020. Front. Bioeng. Biotech. doi:10.3389/fbioe.2020.604860
, Spring Loaded bracing is a promising solution for many patients who struggle with pain due to PF involvement.

Multiple Forces Reduced

Each TCO brace model significantly reduced PF, TF, PC ligament, PT and QT forces during a deep knee bend test.

Reduced Joint Load

Each TCO brace model significantly reduced knee joint loads by at least 32% when compared to the non-braced condition.

Replicates & Extends Previous Research

Results corroborate the knee joint offloading capabilities of a TCO, as demonstrated in a previous study (Budarick et al. 2020).

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