This is a method for removing tendon scar tissue using high-intensity ultrasound through keyhole surgery. It is used where scar tissue has built up in people with tennis elbow and other joint conditions. It was developed by the Mayo Clinic, and commercialised by Tenex, who rather strangely say that FAST stands for 'Fasciotomy and Surgical Tenotomy', rather than the name Mayo gave it.
It could be of use in some cases of tailbone pain, if scar tissue on tendons is causing the pain.
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