Anatomy and pathology There is a shallow groove on the palmar side of the metacarpal head, which constitutes a narrow and hard osteofibrous canal with the sheath annular ligament. In the activities of the hand, the metacarpophalangeal joint is more active, and the force between the carriage and tendon is greater than that between the interphalangeal joints in flexion, so it is susceptible to friction and inflammation and fibrous hyperplasia, and the osteofibrous canal is progressively narrowed. Tendon also due to bone fiber tube narrowing friction, fiber surface layer degeneration, necrosis, rupture, repair process by volume compensation, volume increase gradually formed ellipsoidal expansion. Expanded body through the bone fiber tube, is “hard squeeze” over, so the sound of popping, called the board machine finger (see Figure). The thumb is more unusual in that there is a pair of phalanges at the metacarpophalangeal joint between which the tendon of the flexor digitorum longus passes. The flexor pollicis brevis has the bunion extensor and bunion flexor tendons terminating on it. The bunion retractor tendon ends on the ulnar side of the phalanx. Here the fibrous conduit of bone is more bony, narrower, and hard on three sides. In addition to the tough sheath of the annular ligament of the flexor digitorum longus overlying the surface, the tendon of the teres major muscle is also attached to the surface between the two seed bones, thus providing a wider coverage. The localization is complicated in treatment. Diagnosis: The incidence of adult boarder’s finger is reported to be more common in females than males, with a ratio of 4:1, and is more common in the thumb and middle finger. The right side is more common than the left side, and the incidence is more common in 40-60 years old, which may be related to the poor repair ability and easy to be damaged during menopause. 15% of the patients have more than one finger involved. According to the degree of injury and local symptoms can be divided into four levels. First level:Local inflammation at the beginning, stenosis is not obvious, when getting up in the morning, the finger stiffness, mild pain, after brushing teeth and washing face and other activities, the symptoms disappeared. No ringing occurs. Grade 2: obvious stenosis, thickening of the annular ligament of the sheath, the beginning of tendon expansion, when you get up in the morning, finger extension and flexion produce popping sound, after the activity, the sound disappears, accompanied by pain, the degree of its degree is related to the degree of inflammation. Grade III: severe stenosis, obvious thickening and sclerosis of the annular ligament of the sheath, tendon enlargement, finger extension and flexion with popping sound all day long, and even after flexion and straightening, the other hand is needed to assist the straight to complete the movement. Grade 4: The stenosis is so severe that the thickening of the annular ligament and the enlargement of the tendon bulge can not pass through the fibrous canal of the bone, and the finger extension and flexion movements are limited, and the finger is “fixed” in the straightened position. Due to the lack of movement, the fingers appear swollen with impaired lymphatic return. In grade 1 and 2 patients, the metacarpophalangeal joint tenderness is mild and the tendon sheath is slightly thickened, while grade 3 and 4 patients are more serious. And grade IV patients are often misdiagnosed as arthropathy. Careful examination and questioning of the medical history will reveal the evolution of the first, second and third grades, coupled with the obvious palmar surface tenderness of the metacarpophalangeal joints, it is easier to make a diagnosis. Third, the treatment with bladed needle cutting method, compared with the traditional surgical treatment is less painful, safe, immediate effect, no surgical adhesion or even leave scars and other sequelae, a cure.