MRI
There is discontinuity of the flexor pollicis longus tendon with 29 mm gap, extending from the carpal tunnel to the level of the thumb proximal phalanx. No obvious edema is noted along the course of the tendon. This represents chronic tear.
The peritendinous fluid signal is present within the first dorsal extensor compartment (abductor pollicis longus and extensor pollicis brevis tendons) related to tenosynovitis.