Trigger finger

　　Tenosynovitis of the flexor tendons of the fingers in children, also known as congenital narrow tenosynovitis, is caused by abnormal thickening of the A1 pulley, leading to narrowing of the sheath. The flexor tendons form a hard nodule near the A1 pulley, leading to dysfunction of finger flexion and extension. However, whether the pathogenic cause is congenital or acquired is still controversial.

　　The causes of tenosynovitis of the flexor tendons of the fingers in adults are more related to the fatigue of the affected fingers. Due to repeated flexion and extension of the affected fingers in a short period of time, the tenosynovial tissue undergoes aseptic inflammatory changes, leading to thickening of the tenosynovium and narrowing of the sheath. On the other hand, due to fatigue or changes in hormone levels in women (pregnancy or menstrual period), the fingers flexor tendons become swollen, and the volume of the tenosynovium is limited, so it can also form a narrow compression relative to the swollen tendons.

　　In addition to the above causes, there are some aggravating factors for some diseases, such as cold stimulation, diabetics, patients with peritenon bursitis and rheumatoid arthritis, etc.

The early symptoms of trigger finger are that during the flexion and extension of the fingers, the patient feels acid and sore on the palmar side of the metacarpophalangeal joint. In severe cases, there may be a popping sound, even a lock, leading to dysfunction of flexion and extension of the fingers.

　　The early symptoms of tenosynovitis of the flexor tendons of the fingers are that during the flexion and extension of the fingers, the patient feels acid and sore on the palmar side of the metacarpophalangeal joint. In severe cases, there may be a popping sound, even a lock, leading to dysfunction of flexion and extension of the fingers. These symptoms are more severe upon waking up in the morning, and some symptoms are relieved in the afternoon. Cold stimulation often aggravates the symptoms. Tenosynovitis of the flexor tendons of the fingers in children often involves the thumb, while adults can be affected by all fingers. Physical examination may show tenderness at the level of the A1 pulley, and some patients may feel a hard nodule near the A1 pulley, which can slide back and forth with the flexor tendons during flexion and extension. In severe cases, the affected finger may present with a fixed flexion deformity (lock), with limited active and passive extension.

　　Currently, there is no clear preventive measure for tenosynovitis of the flexor tendons in children. However, for adults with tenosynovitis of the flexor tendons, it can be prevented by reducing fatigue, avoiding cold stimulation, controlling blood sugar well (for diabetics), early treatment of peritenon bursitis and rheumatoid arthritis, and other methods.

　　Tenosynovitis of the flexor tendons of the fingers can generally be diagnosed by clinical examination. For atypical cases, B-ultrasound examination can be used for diagnosis. Although magnetic resonance imaging has a high sensitivity, considering its high cost, it is still not advisable to use it as the first choice of auxiliary examination.

   The diet of trigger finger patients should be light and easy to digest, with an emphasis on eating more vegetables and fruits, and a reasonable diet should be followed, ensuring adequate nutrition. In addition, patients should also pay attention to avoiding spicy, greasy, and cold foods.

　　1. Conservative Treatment

　　For adult cases with an initial onset, conservative treatment is often effective. Conservative treatment includes immobilizing the affected finger, avoiding cold stimulation, physiotherapy, and using blood-activating, edema-reducing, and pain-relieving drugs in combination.

　　For pediatric patients, local massage can be performed to straighten the affected finger, and methods such as bracing fixation can be used for treatment. It is reported that about 40% of such cases can be cured by conservative treatment.

　　2. Closed Treatment

　　Dexamethasone-like preparations can be used in combination with a small amount of local anesthetic to be injected locally into the A1 tenosynovium to achieve the effects of anti-inflammatory and edema reduction. Some patients show significant efficacy, but if there is continued strain after closure, it is easy to recur, and it is not advisable to inject it repeatedly or repeatedly, as there have been reported cases of tenosynovitis leading to tendon rupture due to repeated closure injections. In addition, closed treatment is not recommended for pediatric patients.

　　3. Percutaneous Release Treatment with a Small Needle Knife or Thick Needle

　　This type of treatment belongs to a minimally invasive treatment that can be completed in an outpatient setting. It involves cutting and releasing the A1 pulley through the skin using a small needle knife or a thick needle, which requires the operation to be performed by an experienced doctor because it is not performed under direct vision, and there is a risk of tendon avulsion, injury to surrounding nerves and blood vessels. Some children's radial digital nerves cross the A1 pulley, so it is not recommended to use a small needle knife or a thick needle to treat children with flexor tenosynovitis.

　　4. Surgical Treatment

　　If the above treatments are ineffective, surgical treatment can be considered. Surgery can protect the digital nerves and vascular bundles under direct vision and accurately and completely release the A1 pulley. If the surgery is performed under local anesthesia, the patient can actively flex the fingers during the operation to judge the sliding nature of the tendons and whether there is any click. The next day after the operation, the flexion and extension exercises of the finger function should begin, otherwise, tendinous adhesions may occur easily, leading to postoperative finger movement disorders.