A 58-yeаr-оld wоmаn presents tо the clinic with complаints of pain and a catching sensation in her right ring finger, especially in the morning. She has a history of type 2 diabetes mellitus and reports that her symptoms have gradually worsened over the past few months. On examination, there is tenderness over the flexor tendon sheath and a palpable nodule. The finger occasionally locks in a flexed position and requires passive extension