Have you already had an MRI for a plantar plate sprain, but you are still not getting better?
That happens frequently with runners who contact me for second opinions. They have already had an MRI, they have already tried treatment, but they still do not understand exactly how severe the plantar plate injury is or what they should do next.
In this episode, I explain four questions I think you should ask your doctor when you are a runner with a plantar plate injury and the MRI has not given you a clear path back to running.
Click here to get the free Plantar Plate Masterclass for Runners.
An MRI creates many individual images, or slices, through your foot. One way to think about those slices is like looking through the individual openings between vertical blinds. Different slices show different portions of the structure.
This matters because the plantar plate is a very small structure. Daniel Hatch, DPM, described the lesser-toe plantar plate as approximately 19 mm long and about 2 mm thick. He also described a thin fibrous proximal attachment measuring approximately 0.4 mm.
Yet many runners who contact me have MRI studies obtained with slices approximately 3.5 or 4 mm thick.
Research involving other joints and orthopedic structures suggests that slice thickness can affect the ability to identify small or subtle abnormalities. These studies are not direct plantar-plate comparisons, but they provide useful context when considering MRI resolution.
For example, Chen and colleagues compared 2-, 3-, 4-, and 5-mm MRI slices when evaluating sacroiliac joint erosions. The 2- and 3-mm images demonstrated significantly better diagnostic accuracy than the 4- and 5-mm images.
A 2024 elbow MRI study by Yi and colleagues compared 1-mm and 3-mm imaging for tendon and ligament abnormalities. The authors specifically examined whether routinely used slice thicknesses could overlook small or subtle lesions and reported improved diagnostic performance with thin-slice imaging using deep-learning reconstruction.
Research on knee MRI has also reported improved diagnostic performance when 2-mm sequences were added to a routine protocol using thicker slices.
Most importantly for this discussion, Mann and colleagues published a plantar-plate MRI study using a dedicated protocol with 2- to 3-mm slices and no gap. Their study evaluated subtle degenerative abnormalities as well as complete plantar-plate ruptures.
None of those studies proves that a plantar plate tear will be missed simply because an MRI uses 3.5- or 4-mm slices. But when you are trying to evaluate a structure only about 2 mm thick, it is reasonable to ask whether the images provide enough detail to evaluate the specific structure that hurts.
Your radiologist reads the MRI and creates a report. But the radiologist usually has not examined you, heard your complete story, or watched how your symptoms have changed.
Your treating doctor has that clinical context.
A foot MRI can contain hundreds of individual images. Ask your doctor whether she or he personally reviewed those images instead of relying only on the written radiology report.
The radiology report is useful, but it is not the MRI itself.
Ask your doctor to pull up the actual MRI images and show you the plantar plate.
Where is the abnormality? How large is it? Is there evidence of degeneration, a partial tear, or a complete rupture? Does that abnormality correspond to the exact location of your symptoms?
Seeing the suspected injury can help you understand the problem and also provides another opportunity to make sure the imaging findings actually correlate with your clinical examination.
If your symptoms strongly suggest a plantar plate injury but the MRI does not clearly show one, ask whether ultrasound could provide additional information.
One frequently cited study by Rockett and colleagues compared ultrasound and MRI with surgical findings in patients with tendon abnormalities around the ankle. Ultrasound demonstrated 100% sensitivity and 94.4% accuracy, while MRI demonstrated 23.4% sensitivity and 65.75% accuracy in that particular study.
Importantly, that study evaluated tendons around the ankle, not plantar plate ligaments. It should not be interpreted as evidence that ultrasound is always more accurate than MRI for plantar plate injuries. It does demonstrate why another imaging modality can sometimes provide useful additional information when clinical findings and MRI findings do not seem to agree.
Time matters when you are a runner.
Every day spent unnecessarily immobilized in a fracture walking boot, on crutches, or sitting still can affect strength and running fitness.
That does not mean you should ignore an injury or avoid necessary protection. It means that restrictive treatment should be based on the best information you can get about what is actually injured and how severe the injury is.
You need an accurate plan, a workable plan, and a plan based on things you can measure instead of simply guessing.
Hatch DJ. Anatomy: Plantar Plate. Clinics in Podiatric Medicine and Surgery. 2022;39(3):411-419.
DOI: 10.1016/j.cpm.2022.02.004
Rockett MS, Waitches G, Sudakoff G, Brage M. Use of Ultrasonography Versus Magnetic Resonance Imaging for Tendon Abnormalities Around the Ankle. Foot & Ankle International. 1998;19(9):604-612.
DOI: 10.1177/107110079801900907
Chen M, et al. Diagnostic Performance for Erosion Detection in Sacroiliac Joints on MR T1-Weighted Images: Comparison between Different Slice Thicknesses. European Journal of Radiology. 2020;133:109352.
DOI: 10.1016/j.ejrad.2020.109352
Yi J, Hahn S, Lee HJ, Lee Y, Bang JY, Kim Y, Lee J. Thin-slice elbow MRI with deep learning reconstruction: Superior diagnostic performance of elbow ligament pathologies. European Journal of Radiology. 2024;175:111471.
DOI: 10.1016/j.ejrad.2024.111471
Visser JJ, Weustink AC, Oei EHG, Muradin GS. MRI of the Knee—Do 2 Millimeter Slices Improve Diagnostic Performance? Radiological Society of North America 2013 Scientific Assembly and Annual Meeting.
View RSNA abstract
Mann TS, Nery CAS, Baumfeld D, Fernandes E. Degenerative injuries of the metatarsophalangeal plantar plate on magnetic resonance imaging: a new perspective. Einstein (São Paulo). 2022;20:eAO6543.
DOI: 10.31744/einstein_journal/2022AO6543
If you are a runner with a plantar plate sprain that is not getting better and you want to take a deeper dive into what you can do next, check out the free Plantar Plate Masterclass for Runners.
Click here to get the free Plantar Plate Masterclass for Runners.
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