Intra-Articular Injection of the Carpometacarpal Joint of the Fingers

Indications and Clinical Considerations

The carpometacarpal joints are susceptible to developing arthritis from a variety of conditions that have the ability to damage the joint cartilage. Osteoarthritis of the joint is the most common form of arthritis that results in carpometacarpal joint pain. It is more common in females. Although the carpometacarpal joint of the thumb is most often affected, the other carpometacarpal joints also may develop arthritis, especially after trauma. Rheumatoid arthritis, posttraumatic arthritis, and psoriatic arthritis also are common causes of carpometacarpal pain secondary to arthritis. Less common causes of arthritis-induced carpometacarpal pain include the collagen vascular diseases, infection, and Lyme disease. Acute infectious arthritis usually is accompanied by significant systemic symptoms, including fever and malaise, and should easily be recognized by the astute clinician and treated appropriately with culture and antibiotics rather than injection therapy. The collagen vascular diseases generally manifest as a polyarthropathy rather than a monoarthropathy limited to the carpometacarpal joint, although carpometacarpal pain secondary to collagen vascular disease responds exceedingly well to the intra-articular injection technique described later.

The majority of patients with carpometacarpal pain secondary to osteoarthritis and posttraumatic arthritis report pain localized to the dorsum of the wrist. Activity associated especially with flexion, extension, and ulnar deviation of the carpometacarpal joints exacerbates the pain; rest and heat provide some relief. The pain is constant and is characterized as aching and may interfere with sleep. Some patients note a grating or “popping” sensation with use of the joint, and crepitus may be present on physical examination.

In addition to the previously mentioned pain, patients with arthritis of the carpometacarpal joint often experience a gradual decrease in functional ability with decreasing pinch and grip strength, making everyday tasks, such as using a pencil or opening a jar, quite difficult. With continued disuse, muscle wasting may occur and an adhesive capsulitis with subsequent ankylosis may develop.

Plain radiographs are indicated for all patients with carpometacarpal pain. On the basis of the patient’s clinical presentation, additional testing may be indicated, including complete blood cell count, sedimentation rate, and antinuclear antibody testing. Magnetic resonance imaging and/or ultrasound imaging of the carpometacarpal joint is indicated if joint instability is suspected.

Clinically Relevant Anatomy

The carpometacarpal joints of the fingers are synovial plane joints that serve as the articulation between the carpals and the metacarpals and also allow articulation of the bases of the metacarpal bones with one another ( Fig. 86.1 ). Movement of the joints is limited to a slight gliding motion, with the carpometacarpal joint of the little finger possessing the greatest range of motion ( Fig. 86.2 ). The joint’s primary function is to optimize the grip function of the hand by allowing the hand to cup ( Fig. 86.3 ). In most patients, there is a common joint space, and the joint is strengthened by anterior, posterior, and interosseous ligaments. The carpometacarpal joints are subject to dislocation from trauma, and failure to promptly treat the dislocation can result in significant impairment of grasp. Such dislocations are often seen in motorcycle handlebar injuries ( Fig. 86.4 ).