The radiocarpal joint is an ellipsoidal joint formed by the radius and the articular disc proximally and the proximal first row of the carpal bones distally (Fig. 64.1). The primary function of the radiocarpal joint is to aid in orientation of the hand in space for crucial functions like eating and drinking by allowing flexion, extension, adduction, and abduction of the wrist. The joint’s articular cartilage is susceptible to damage, which, if left untreated, will result in arthritis with its associated pain and functional disability. Osteoarthritis of the joint is the most common form of arthritis that results in radiocarpal joint pain and functional disability, with rheumatoid arthritis, posttraumatic arthritis, and crystal arthropathy also causing arthritis of the radiocarpal joint. Less common causes of arthritis-induced radiocarpal joint pain include the collagen vascular diseases, infection, villonodular synovitis, and Lyme disease. Acute infectious arthritis of the radiocarpal joint is best treated with early diagnosis, with culture and sensitivity of the synovial fluid, and with prompt initiation of antibiotic therapy. The collagen vascular diseases generally manifest as a polyarthropathy rather than a monoarthropathy limited to the radiocarpal joint, although radiocarpal pain secondary to the collagen vascular diseases responds exceedingly well to ultrasound-guided intra-articular injection of the radiocarpal joint.

Patients with radiocarpal joint pain secondary to arthritis, gout, synovitis, and collagen vascular disease-related joint pain complain of pain that is localized to the distal forearm and wrist.

Activity, including flexion, extension, adduction, and abduction, makes the pain worse, with rest and heat providing some relief. The pain is constant and characterized as aching. Sleep disturbance is common with awakening when patients roll over onto the affected upper extremity. Some patients complain of a grating, catching, or popping sensation with range of motion of the joint, and crepitus may be appreciated on physical examination.

Functional disability often accompanies the pain of many pathologic conditions of the radiocarpal joint. Patients will often notice increasing difficulty in performing their activities of daily living and tasks that require flexion, extension, adduction, and abduction of the wrist such as using a computer keyboard, screwdriver, and corkscrew or tuning a doorknob. If the pathologic process responsible for the radiocarpal pain is not adequately treated, the patient’s functional disability may worsen and muscle wasting and ultimately a frozen radiocarpal joint may occur.

Plain radiographs are indicated in all patients who present with radiocarpal joint pain (Fig. 64.2). Based on the patient’s clinical presentation, additional testing may be indicated,
including complete blood cell count, sedimentation rate, and antinuclear antibody testing. Magnetic resonance imaging (MRI) or ultrasound of the radiocarpal joint is indicated if fracture, effusion, tendinopathy, crystal arthropathy, joint mice, synovitis, bursitis, or ligamentous injury is suspected (Fig. 64.3).

The radiocarpal joint of the wrist is a biaxial, ellipsoid-type joint that serves as the concave articulation between the distal end of the radius and the articular disc above and the scaphoid, lunate, and triquetral bones below (see Figs. 64.1 and 64.4). The joint optimizes hand function by allowing flexion and extension as well as abduction, adduction, and circumduction of the wrist. The joint is a synovial-lined true joint with an intra-articular space that allows easy access for intra-articular injection, although septa within the synovial space may limit the flow of injectate. The entire joint is covered by a dense capsule that is attached above the distal ends of the radius and ulna and below the proximal row of metacarpal bones. The anterior and posterior joint is strengthened by the anterior and posterior ligaments, with the medial and lateral ligaments strengthening the medial and lateral joint, respectively. The wrist joint also may become inflamed as a result of direct trauma or overuse of the joint.