Chronic inflammatory scar with narrowing of fibroosseous tunnel (1cm long) of first extensor compartment (along radial styloid covered by extensor retinaculum and contains APL- abductor pollicis longus and EPB - extensor pollicis brevis tendons)
Causes:
Pregnancy
First 3 months of lactation, likely to be endocrinal
MRI:
Axial images are best
Thickening of tendon sheath of first extensor compartment and diffuse irregular signal intensity in adjacent subcutaneous fat on T1 and T2
