Chapter 221: Charcot Arthropathy

PATIENT STORY

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.

INTRODUCTION

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.

SYNONYMS

Charcot foot, Charcot neuroarthropathy.

EPIDEMIOLOGY

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.

RISK FACTORS

• Advanced peripheral neuropathy.

• Micro- or macrotrauma.

• Microangiopathy.

• Nephropathy.

• Genetic component might exist.

DIAGNOSIS

The diagnosis of Charcot arthropathy is suspected based on the presentation and confirmed with imaging.

CLINICAL FEATURES

• 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 with an open wound ...