A 48-year-old man with a 19-year history of diabetes mellitus, type 2, presents with a 2-week history of an erythematous, hot, swollen left foot (Figure 221-1). Three days ago, he noticed pain in his foot. The patient does not recall any trauma to his foot. He denies fever or chills. He takes multiple medications for diabetes, but he has been above his glycemic targets for many years. The radiograph of his foot (Figure 221-2) shows midfoot osteopenia, an early sign of acute Charcot arthropathy.
Charcot arthropathy in the right foot. Notice the swelling and discoloration compared to the contralateral side. (Reproduced with permission from Javier La Fontaine, DPM.)
Lateral view of same foot demonstrating midfoot osteopenia, an early sign of acute Charcot arthropathy. (Reproduced with permission from Javier La Fontaine, DPM.)
Charcot arthropathy is a rare but devastating complication in patients with neuropathy. Patients often present with pain, swelling, and erythema, similar to the presentation of a foot infection. Patients may have a rockerbottom foot deformity. Radiographs confirm the diagnosis.
Charcot foot, Charcot neuroarthropathy.
The incidence of Charcot arthropathy in diabetes ranges from 0.1% to 5%.1
ETIOLOGY AND PATHOPHYSIOLOGY
Charcot arthropathy is a gradual destruction of the joint in patients with neurosensory loss, most commonly seen in patients with diabetic neuropathy.2 The pathogenesis is unknown. Historical theories include:
Neurotraumatic theory—Following sensory-motor neuropathy, the resulting sensory loss and muscle imbalance induces abnormal stress in the bones and joints of the affected limb, leading to bone destruction.
Neurovascular theory—Following the development of autonomic neuropathy, there is an increased blood flow to the extremity, resulting in osteopenia from a mismatch in bone reabsorption and synthesis.
Recently, it has been suggested that glycation of ligament, joint capsule, and bone abnormalities3 along with a chronic prolonged inflammatory process may lead to joint destruction.
Stretching of the ligaments because of joint effusion may lead to joint subluxation.
The diagnosis of Charcot arthropathy is suspected based on the presentation and confirmed with imaging.
Red, hot, swollen foot (see Figure 221-1).
Even with neurosensory loss, 71% of patients present with the chief complaint of pain.4
Rockerbottom foot deformity is a classic finding of this entity (Figure 221-3).
Patients may present ...