Flexor tenosynovitis is a medical condition in which one or more hand tendons become inflamed, painful, and stiff. An affected finger may swell at the base and spontaneously lock into and release from a fixed position. The disorder can arise due to an infection, frequent overuse of a finger joint, or a complication of rheumatoid arthritis. Treatment for flexor tenosynovitis depends on the underlying cause, but most instances can be relieved by taking anti-inflammatory and antibiotic medications. Surgery may be necessary in severe cases to manually release the built-up tension in the flexor tendons.
The hand contains several tendons that connect bone, muscle, and cartilage tissue. Each flexor tendon in the fingers and palm is lined with a fluid-filled sheath that provides protection and lubrication, allowing for easy bending of the finger joints. In the case of flexor tenosynovitis, the sheath becomes inflamed, fluid builds up, and the joint becomes difficult or impossible to comfortably use. Any tendon can be affected, but the condition most frequently arises in the thumb and ring finger.
Many different bacteria and viruses can lead to flexor tenosynovitis. Most cases result from direct infections occurring with deep puncture wounds, animal bites, or severe cuts. Flexor tenosynovitis can also arise as a chronic overuse injury, similar to tendinitis in larger body joints. In addition, some people experience finger joint stiffness and tenosynovitis as symptoms of rheumatoid arthritis.
An individual who suffers from flexor tenosynovitis may experience a number of physical symptoms. The most telling sign of the condition is called trigger finger, referring to a finger's tendency to suddenly lock into a bent position and then relax again just as abruptly. A joint may become swollen and feel tender to the touch. As flexor tenosynovitis progresses, a finger's range of motion may be severely limited and pain can start to radiate through the hand and forearm.
A person who experiences acute or chronic finger pain should schedule an appointment with a doctor right away. A physician can usually diagnose the condition by performing a thorough physical examination and taking diagnostic imaging scans of the hand. A magnetic resonance imaging scan can reveal clinical signs of flexor tenosynovitis, including fluid buildup and swelling in the tendon sheath. If the physician suspects an infection, he or she may collect a blood sample to check for specific pathogens.
After making a diagnosis, the doctor can determine the best course of treatment. Immediate symptoms of pain and swelling are generally managed with oral drugs or corticosteroid injections. A patient may receive antibiotics in an infection is present. If problems are not relieved with medications, a surgeon may need to make a puncture in the tendon to drain excess fluid. Another procedure called a tendon release can be performed to stretch and relax the affected tendon. After receiving treatment, a patient is generally instructed to perform light stretching exercises to rebuild strength and flexibility over the course of several months.