Figure 1. Normal Foot vs. Charcot Foot
By Nikki Elmi
Charcot foot is a progressive, degenerative condition that severely impacts the structure of the foot and ankle, leading to deformities and, in extreme cases, amputation if untreated. Primarily associated with neuropathy, especially in diabetic patients, Charcot foot disrupts the bone and joint alignment due to weakened bone structures and impaired sensation. As a result, early intervention is essential to prevent long-term complications, including ulcers and severe infections.
Fig 2. X-ray of a Charcot Foot
At the cellular level, the pathophysiology of Charcot foot begins with peripheral nerve degeneration due to diabetes, leading to a loss of sensory and proprioceptive functions. When unnoticed microtrauma occurs, it triggers a local inflammatory response characterized by the release of signaling molecules that attract immune cells, such as macrophages and neutrophils, to the injury site. These activated immune cells release pro-inflammatory cytokines (like IL-1, IL-6, and TNF-alpha), promoting further inflammation and increasing vascular permeability, which results in edema and warmth. This inflammatory environment stimulates osteoclasts to increase bone resorption while impairing osteoblast function, leading to decreased bone density and joint stability. Concurrently, the release of matrix metalloproteinases (MMPs) degrades the extracellular matrix, further compromising cartilage and bone integrity. As the joints become unstable and undergo structural changes, abnormal load distribution during ambulation exacerbates the cycle of injury, inflammation, and tissue damage, ultimately resulting in the progressive deformities characteristic of Charcot foot.
Fig 3. The Pathophysiology Behind Charcot
The most common cause of Charcot foot is diabetic neuropathy, where chronic high blood sugar damages nerves in the extremities, especially the feet. Patients with diabetes or other conditions causing neuropathy are at high risk, particularly if they’ve had diabetes for a long time or have poorly controlled blood sugar.
Charcot foot progresses through four stages: the prodromal stage, characterized by subtle signs like warmth and swelling without noticeable deformity; the developmental stage, marked by rapid destruction of bone and joint structures due to inflammation, leading to significant deformity; the coalescence stage, where inflammation subsides and new bone formation begins, providing some stabilization; and the reconstruction stage, during which remodeling occurs, resulting in either stable or unstable foot architecture based on the extent of prior damage.
Fig 4. The Four Stages of Charcot
To treat Charcot foot, the first step is immobilization using a total contact cast or custom boots to prevent further injury while allowing healing. In more severe cases, surgery may be necessary, such as osteotomy, which involves cutting and repositioning bones to correct deformities, or arthrodesis, where joints are fused to eliminate movement and stabilize the foot. The surgeon's goal is to restore proper alignment, improve foot function, and reduce pain, ultimately helping prevent further complications. Post-surgery, ongoing use of custom orthotics and physical therapy is typically required for optimal recovery and foot health
Fig 5. X-rays showing before and after reconstruction surgery
Charcot foot is a complex and potentially life-altering condition, particularly for those with diabetic neuropathy. Early diagnosis, proper management, and regular foot care are essential to preventing serious complications. With timely intervention and adherence to treatment, patients can manage symptoms effectively, though long-term follow-up is necessary to avoid recurrence and maintain mobility.
References:
Cleveland Clinic. (2022, January 10). Charcot foot. Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/15836-charcot-foot
Lower Extremity Review. (n.d.). Charcot foot and ankle surgery: Reconstruction. https://www.lowerextremity.com/charcot-foot-and-ankle-surgery-reconstruction
Straits Podiatry. (n.d.). Charcot foot. Straits Podiatry. https://www.straitspodiatry.com/conditions/charcots-foot/
The Wound Pros. (2022, September 9). Charcot foot. https://www.thewoundpros.com/post/charcot-foot
UCSF Health. (n.d.). Charcot foot. UCSF Health. https://www.ucsfhealth.org/medical-tests/charcot-foot
Wukich, D. K., & Rouse, M. (2013). Charcot foot and ankle. PMC, 3733015. https://pmc.ncbi.nlm.nih.gov/articles/PMC3733015/ Assessed and Endorsed by the MedReport Medical Review Board