Treatment of Chronic Isolated Finger Flexor Tenosynovitis Through 50% Dehydrated Alcohol Installation
A 56-year-old man visited the rehabilitation department at our hospital with major complaints of painful swelling on his right forefinger. The patient was an office worker and had no history of external trauma. He indicated '2' on the visual analogue scale (VAS) in ordinary position but indicated '4' during finger extensions. On physical examination, tenderness-free edema was observed on his right forefinger, but there were no suspected infections e.g., localized burning sensation or redness. According to manual muscle testing using the Medical Research Council scale for muscular strength, the right forefinger measured 5 during both flexion and extension. Abnormalities were not observed in the metacarpophalangeal joint during the right forefinger extension, but its flexion angle did not exceed 30 degrees.\nThe patient had taken hypoglycemic drugs due to diabetes, but had no past medical histories related to gout, arthritis, and tuberculosis. He tested negative on a tuberculosis polymer chain reaction test and chest radiography performed at another hospital. He underwent a blood test after visiting this hospital, and white blood cells, red blood cells, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) were all within normal levels. He was also tested negative for anti-cyclic citrullinated peptide, rheumatoid factor, and antinuclear antibodies.\nOn the longitudinal sectional image of his magnetic resonance imaging (MRI) scan performed at another hospital, synovial fluid retention was observed and the flexor tendon had increased in cross-sectional area, which was almost a positive proof of flexor tenosynovitis (). On the transverse image, the synovial cyst significantly increased in cross-sectional area (). He had had such symptoms for 9 months before visiting this hospital. Pharmacotherapy and physiotherapy were performed for 4 months and steroid was injected 3 times, but there were no improvements in symptoms.\nSimple radiography, performed at this hospital, did not show noteworthy abnormalities, but ultrasonography iU22 (Philips Medical System, Bothell, WA, USA) showed proliferations of blood cells in the right forefinger on both the longitudinal section and the transverse section. In addition, for hyperechoic characteristics, profuse synovial fluid retention and flexor thickening were noted through ultrasonography (). Power Doppler ultrasonography showed blood being supplied to the proliferated synovial cells ().\nUnder ultrasonography guidance, 1 mL of 50% ethanol was injected into the tendon sheath of the proximal interphalangeal joint of the forefinger where blood flow had increased. The patient did not show side effects excluding pain at the injection site.\nOn the second hospital visit (a month later), the VAS score fell to 1 even during joint movements and the range of joint motion approached 60 degrees. However, swelling remained.\nOn the third hospital visit (10 months later), the range of joint motion was the same as before. The VAS score had risen to 2 and edema was persistently visible. An additional alcohol injection was performed as before.\nOn the fourth hospital visit (12 months later), he indicated 'zero' on VAS during rest and during flexion and extension of the metacarpophalangeal joint of the right forefinger. On physical examination, the flexion angle approached 70 degrees and tenderness on the forefinger did not occur. In addition, edema had subsided significantly.\nOn the fifth hospital visit (22 months after the first alcohol injection), the VAS score was still 'zero' and edema had subsided remarkably from the previous 10 months (the fourth hospital visit). On physical examination, he did not show any pains during movement of the metacarpophalangeal joint of the right forefinger and could flex it 90 degrees.\nUltrasonography showed that synovial cells had proliferated and nutrition was being provided from blood vessels (). Two alcohol injections did not cause noteworthy complications during the follow-ups conducted for 22 months.