Trigger finger may be seen in rheumatoid arthritis (RA). This represents a tenosynovitis of the flexor tendon sheath with a nodular enlargement on the flexor tendon itself. Attempted passage of the nodule is blocked by the unyielding pulleys, and the patient describes a painful locking of the finger in flexion. At present, injection of adrenocortico-steroid into the tendon sheath is commonly used to treat this phenomenon. However it falls short of bringing about a satisfactory prognosis for frequent relapses.
Eighteen RA patients with trigger and locking finger participated in this study where the effects of the low power Ga-Al-As diode laser (10mW, C. W., 830nm) were reviewed. One tender point on the flexor tendon sheath in the palm was irradiated for 1 to 5 minutes. The therapy was given once a week.
After one treatment 72.2% of the patients improved at least 2 steps in the 10 step visual analogue scale of pain. 38.9% of the patients' trigger and locking fingers were alleviated. With further treatments the percentage of patients who improved 2 or more steps in the pain scale rose slightly to 77.8%, while the percentage for remedied trigger and locking fingers almost doubled to 72.2%. The date shows that only after recurrent treatments of laser irradiation did the pain relief effect become closely related to improvement of the trigger and locking finger.