How to inject the CMC I joint
By Dr. Jan Claeys, M.D.
A practical film illustration on how to inject the carpo-metacarpal 1 joint.
PATIENT'S POSTURE The patient sits with his forearm at mid-rotation lying on the couch.
PRODUCT 1 ml triamcinolone acetonide (10 mg/ml)
SYRINGE 1 ml tuberculin syringe
NEEDLE 0.6x25 mm (23 G1)
TECHNIQUE The joint is searched for by asking the patient to move the thumb to and fro while the palpating thumb slides proximally over the dorsum of the first metacarpal bone. It is found where the palpating thumb ceases to feel the to and fro movement of the first metacarpal bone. The joint is made more accessible by an assistant, pulling on the thumb and exerting counter-pressure on the patient’s forearm. The needle is directed at the opened joint at an angle of 60° to the horizontal plane. It hits bone at about 1 cm ; it is moved about until no resistance is felt (at about 1.5 cm). Here, the intra-articular injection is slowly given.