Am Fam Physician. 2003;68(10):1912
to the editor: In the article, “Diagnostic and Therapeutic Injection of the Wrist and Hand Region,”1 the authors describe office procedures for injecting various areas of the wrist and hand region. I would like to add that 27-gauge needles are very effective for these techniques, including injection procedures for digital flexor tenosynovitis (trigger finger), de Quervain's tenosynovitis, first carpometacarpal joint, and carpal tunnel syndrome. These needles hurt less because they are thinner. For de Quervain's, first carpometacarpal joint, or for trigger fingers, the needle should be 0.5 inches long. For carpal tunnel, they should be 1.5 inches long in order to penetrate the carpal tunnel near the site of maximal compression of the nerve. For primary care physicians who are struggling with injecting the first carpometacarpal joint, I would like to add another important clinical note. The superficial branch of the radial nerve can easily be palpated just ulnar to the cephalic vein at the wrist “interns vein” when viewed from the dorsal aspect. If one palpates the cephalic vein and rotates toward the ulnar side of the hand over the radius, one can feel a small spaghetti-sized nerve roll between the fingers. This is the superficial branch of the radial nerve. Before injection of the first carpometacarpal joint, 3.0 to 5.0 mL of 1.0 percent lidocaine (Xylocaine) may be injected around this nerve with a pre-frozen 30-gauge needle,2 with caution not to enter the cephalic vein. Freezing of the needle in its sterile package reduces the pain of anesthetic injection. After a few minutes, excellent anesthesia to the dorsal aspect of the thumb, index finger, and carpometacarpal joint is produced. Subsequently, the carpometacarpal joint may be injected, and passageway into this joint is easier because the dorsal aspect of the joint is numb. It is very difficult to cannulate this small joint, even with traction on the thumb, and patients are most grateful that the pain from missed attempts is alleviated. Once the injection does go into the joint, it is still painful, even with local anesthetic added; however, the gain to the physician is peace of mind concerning the patient's pain level until the joint is actually pierced.
in reply: We would like to thank Dr. Denkler for his useful comments. We agree that a 27-gauge needle is useful in many circumstances. The choice of needle gauge and length must be guided by clinical judgment and will vary based on the patient's body habitus. Similarly, Dr. Denkler's technique of identifying the superficial branch of the radial nerve can be difficult depending on variables such as the patient's skin thickness and subcutaneous fat. Nevertheless, we thank him for sharing his comments and experience. Reducing a patient's pain or discomfort is always a worthwhile goal.