Synovial thickness in carpal tunnel was measured by high-resolution ultrasonography to evaluate the relation of synovial hypertrophy in idiopathic carpal tunnel syndrome.

Thickness of synovium of flexor tendons in 46 hands of idiopathic carpal tunnel syndrome and 50 hands of normal control were measured quantitatively by high-resolution ultrasonography. The patients were classified into three groups according to the clinical severity: Group I had typical clinical symptoms and positive provocation test (17 cases) , Group II had sensory decreation on the dermatome of median nerve (21 cases) , and Group III had sensory decreation and thenar muscle weakness. The thickness of flexor tendons in the three groups and control group were statistically compared.

: The mean value of thickness of carpal tunnel syndrome was 1.06mm and that of control group was 0.87mm (p=0.012) . Positive correlation was revealed according to the clinically classified three groups.

Synovial hypertrophy in carpal tunnel has positive relationships with idiopathic carpal tunnel syndrome, and it reveal possibly the progression of the disease.