The most common neuroma you will be imaging will be a Morton’s Neuroma in the third interspace, although you will also on occasion also be able to identify a Hauser’s Neuroma in the second interspace. The more common Morton’s Neuroma consists of a thickening of the nerve sheath at the convergence of the medial and lateral plantar nerve, and it will appear as a hypoechoic (darker) ovoid mass, riding between the metheads and below the inter-metatarsal ligament (below it anatomically, that is; since your image is inverted on the ultrasound, it will appear above the inter-metatarsal ligament in the image you are viewing).

Tips on scanning for neuromas:

  • The first thing to do is find the met heads, and adjust the angle of your probe until they pop out as nice white (hyperechoic) caps. Everything beyond each met head will fall into shadow since ultrasound cannot penetrate bone, but what you’re looking for are the met heads themselves, and then focusing your attention on the inter-space. Next you will want to try to identify the inter-metatarsal ligament running between (and slightly lower on the image). Once you have that in view, look for the ovoid mass of the neuroma riding below it (below it anatomically, that is; it will appear above it on the ultrasound screen).
  • A neuroma should ideally be scanned across both planes, but you will find the clearest evidence of it when scanning transverse (and it can often be seen with greatest clarity while performing Mulder’s maneuver: lightly compressing the metatarsal heads and making the neuroma pop up in the image when you squeeze and pop back down as you release).
  • Try positioning the probe on the third met head … then sweep to the fourth … then return back to the middle.
  • You will usually find the nerve to appear isoechoic — meaning that it will look the same no matter what angle your probe.)
  • Always keep in mind that one of the purposes of making use of ultrasound in this procedure is to confirm that what the patient has really is a neuroma and not an instance of capsulitis. What you will find under ultrasound examination is that, while both pathologies will appear hypoechoic, a neuroma will fall between the metatarsals, within the inter-space (and will move up and down, retaining its ovoid shape, when you perform Mulder’s maneuver), whereas an instance of capsulitis will appear directly below (below it anatomically; actually above it in the ultrasound image) the met head.

Training Videos

 

 

Sample Images

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If you have a fine example of an image you have captured showing a neuroma or an instance of capsulitis, and if you would be okay with my displaying it here, please email it to me at shawn [at] fisherbiomedical.com. (I can even use Photoshop to take out your name and of course remove the patient’s name, if you would prefer to contribute anonymously.)