100 - Novel single operator technique for first carpo-metacarpal joint injection of 52 year old male

Case Diagnosis: First carpo-metacarpal joint injection

Case Description: A 52 year old male presented to PM&R clinic with chronic focal pain along his left thumb. Physical examination demonstrated tenderness along the left first carpometacarpal joint space with no erythema or bony deformity. Thumb ROM is significantly limited due to pain with a positive grind test. X-ray demonstrates degenerative changes in the first carpo-metacarpal joint space. An ultrasound-guided injection with 0.5mL of lidocaine hydrochloride, 10 mg/mL and 0.5mL of triamcinolone 40mg/mL were injected into the first carpometacarpal joint. On the 4 month follow-up visit patient reports significant improvement in pain with occurrence of pain at night-time with benefit from thumb-spica splint application. On physical exam, the patient achieved 80% of left thumb opposition to the 5th digit.

Discussions: A small-footprint linear array ultrasound transducer (hockey-stick probe) was placed on the volar surface of the left hand to visualize the first carpometacarpal joint space. A 25-gauge needle was placed out-of-plane superiorly to the ultrasound transducer aiming towards the trapezium. Color doppler demonstrated flow of injectate into the joint space with a water-fall like appearance. Our technique injects the first carpo-metacarpal joint from the volar side of the thumb as opposed to the traditional approach from which the injection is performed from the dorsal side of the thumb. Ultrasound guidance is used to precisely locate the joint obviating the need of an assistant to distract the joint. We think this technique may be useful clinically and is worthy of further study.

Conclusions: Carpal-metacarpal joint can be injected from the volar side of the thumb by a singular person. This technique is more practical than the traditional technique which requires an assistant to distract and is less painful for the patient.