The metatarsophalangeal joints of the toes are synovium-lined characterized by the articulation of the rounded articular surfaces of the metatarsal heads into the shallow concavities of the articular surfaces of the proximal end of the first phalanges (Fig. 172.1). The primary function of the metatarsophalangeal joints of the toes is to aid in the gripping function of the foot. The articular cartilage of the metatarsophalangeal joints of the toes is susceptible to damage, which, if left untreated, will result in arthritis with its associated pain and functional disability. Osteoarthritis is seen in the metatarsophalangeal joints of the toes, which results in pain and functional disability, with rheumatoid arthritis, posttraumatic arthritis, and crystal arthropathy also causing arthritis of the metatarsophalangeal joints of the toes. Gout selectively afflicts the metatarsophalangeal joint of the first toe and is called podagra (Fig. 172.2). Less common causes of arthritis-induced pain of the metatarsophalangeal joints of the toes include the other collagen vascular diseases, infection, villonodular synovitis, and Lyme disease. Acute infectious arthritis of the metatarsophalangeal joints of the toes 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 metatarsophalangeal joints of the toes, although pain of the metatarsophalangeal joints of the toes secondary to the collagen vascular diseases responds exceedingly well to ultrasound-guided intra-articular injection.

Patients with pain of the metatarsophalangeal joints of the toes secondary to arthritis, gout, synovitis, and collagen vascular disease-related joint pain complain of pain that is localized to the head of the metatarsals. Activity, including walking and weight bearing, makes the pain worse, with rest and heat providing some relief. The pain is constant and characterized as aching in nature. Sleep disturbance is common with awakening when patients roll over onto the affected foot. Some patients complain of a grating, catching, or popping sensation with range of motion of the joints, and crepitus may be appreciated on physical examination.

Functional disability often accompanies the pain associated with the many pathologic conditions of the metatarsophalangeal joints of the toes. Patients will often notice increasing difficulty in performing their activities of daily living and tasks that require standing, walking, or weight bearing. If the pathologic process responsible for pain of metatarsophalangeal joints of the toes is not adequately treated, the patient’s functional disability may worsen, and muscle wasting and ultimately a frozen metatarsophalangeal joints of the toes joint may occur.

Plain radiographs are indicated in all patients who present with pain of the metatarsophalangeal joints of the toes (Fig. 172.3). 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 or ultrasound of the metatarsophalangeal joints of the toes joint is indicated if fracture, effusion, tendinopathy, crystal arthropathy, joint mice, synovitis, foreign body, bursitis, or ligamentous injury is suspected (Fig. 172.4).