Ultrasound differentiation of two types of de Quervain's disease, the role of retinaculum.

de Quervain’s disease (dQD) is a stenosing tenosynovitis of the first extensor compartment of the wrist, which is formed by the tendons of the abductor pollicis longus (APL) and extensor pollicis brevis (EPB).[1-4] Thirty-three consecutive patients with a clinical diagnosis of dQD underwent US. The inclusion criteria were: (1) a history of pain over the radial aspect of the wrist aggravated by excessive use of the thumb, (2) an orthopaedic diagnosis of dQD, and (3) a positive Finkelstein test. The control group consisted of 24 healthy subjects and was matched for age and sex. The local Ethics committee of the Sacro Cuore Hospital of Negrar approved the study protocol; all participants gave their written informed consent. All studies were performed using a Vivid 7 machine (General Electric) with a 12-MHz matrix linear array transducer. The sonographer was not blinded to the identity of the control subjects. Statistical analysis was performed using the Student’s t-test to assess differences between group means; X2 and Fisher Exact were used for testing the association between qualitative variables.