OBJECTIVETo measure the synovial thickness in the bilateral wrist joints, metacarpophalangeal (MCP) joints and proximal interphalangeal (PIP) joints using high-resolution intraoperative ultrasound probe in healthy young and middle-aged volunteers to determine the normal reference ranges of synovial thickness in the joints.

METHODSThis study was conducted in 100 healthy young and middle-aged volunteers, including 50 male (mean age 36.2∓5.0 years; range 18-54 years) and 50 female (mean age 38.8∓5.5 years; range 20-56 years) individuals. The synovial thickness in the bilateral wrist joints, MCP joints and PIP joints was measured using the GE Logiq S8 18 MHz polo stick-like linear probe array.

RESULTSs No statistical significance was found in the synovial thickness of the wrist joints, MCP joints and PIP joints between the left and right hands, between young (<40 years) and middle-aged (≥40 years) subjects, or between the flexor surface and the extensor surface. In the male subjects, however, the synovial thickness in the wrist joints, MCP joints and PIP joints was significantly greater than that in female subjects. A significant difference was noted in the synovial thickness between the wrist joints, MCP joints and PIP joints.

CONCLUSIONMeasurement of the synovial thickness of the wrist joints, MCP joints and PIP joints using high-resolution intraoperative ultrasound probe is beneficial for early diagnosis and therapy of rheumatoid arthritis.