Diabetic Foot

The foot is an intricate structure comprised of 28 bones that form 25 joints, divided into three regions: the forefoot, midfoot, and hindfoot. The hindfoot contains the calcaneus, or heel bone, while the forefoot comprises the toes, which are made up of small bones called phalanges. Together, the bones of the forefoot and midfoot, supported by muscles and ligaments, create the foot's arches.

These arches play a crucial role in absorbing shock and providing balance. The forefoot facilitates mobility by allowing the body to push off the ground during movement, while the foot bears the weight of the body and offers a stable base.

Nerves convey messages between the foot and brain regarding sensation, positioning, and movement. The circulatory system supplies blood to maintain the health of foot structures. Like other parts of the body, feet are covered with skin, which is thicker on the sole than on the upper surface.

Diabetes-related complications significantly affect foot health, making the feet especially vulnerable. Common issues arise from poor circulation, infections, and nerve damage, resulting in ulcers, deformities, and trauma.

A common complication of diabetes is peripheral neuropathy, a condition characterized by deteriorating nerve function in the limbs. This can lead to a gradual loss of sensation in the hands, arms, legs, and feet. Without the ability to feel pain, individuals may remain unaware of bruises, cuts, blisters, or burns, potentially delaying necessary medical attention. It is crucial for people with diabetes to seek prompt treatment for foot sores, as circulation problems can exacerbate these issues.

Peripheral vascular disease, another common circulation disorder related to diabetes, leads to reduced blood flow to the feet. This restriction hampers the delivery of oxygen and nutrients essential for wound healing, resulting in slow or inadequate recovery from foot injuries, infections, and ulcers.

Individuals with diabetes also tend to be more susceptible to infections. Uncontrolled diabetes can hinder the healing of wounds, particularly on the feet, where infections may worsen or go unnoticed due to neuropathy and vascular disease. Additionally, the constant pressure on the feet from body weight exacerbates foot wounds, while ill-fitting shoes can lead to skin friction and tearing. The warm, moist environment inside shoes is conducive to infections and foot ulcers, which often form over high-pressure areas like bony prominences.

Foot deformities are a common consequence of diabetes, resulting from the deterioration of ligaments and muscles that stabilize foot bones. This deterioration can cause bones to shift out of alignment or the arch structure to collapse. A prevalent condition, hammertoe, often affects the second toe but can occur in multiple toes. Increased pressure on the toe tips and weakened muscle stability can result in a permanently flexed joint, leaving the toe vulnerable to skin ulcers.

Charcot foot, another common deformity associated with diabetic neurogenic arthropathy, affects the metatarsal and tarsal bones in the midfoot and forefoot. This condition leads to the degeneration of foot muscles, ligaments, and joints, resulting in a lack of support and instability, making walking difficult. Inflammation and pressure can lead to bone dislocation, causing the arches to collapse and creating a rocker-bottom appearance.

People with Charcot foot often have impaired or absent pain sensation, temperature perception, and awareness of trauma. This lack of sensation increases vulnerability to injuries, such as fractures and joint dislocations, which may go unnoticed, allowing individuals to continue walking on broken bones.

A healthcare provider can diagnose diabetic foot problems through a physical examination and a discussion of symptoms. Various tests tailored to the individual's symptoms and findings may be conducted, including:

• Non-invasive vascular tests: These tests assess blood circulation in the feet. For instance, a transcutaneous oxygen measurement uses sticky patches on the skin to evaluate oxygen levels, while the ankle-brachial index (ABI) compares blood pressure between the arm and ankle.
• Sensitivity testing: Nylon monofilament testing assesses foot sensation. A thin nylon filament is applied to the skin in various locations, with the patient indicating when they feel it. Temperature sensitivity can also be evaluated using temperature wands.
• Imaging tests: These are often ordered to identify fractures, degeneration, or deformities. X-rays can reveal fracture locations, while CT or MRI scans provide detailed views of the bones, especially for stress fractures not visible on X-rays. All imaging procedures are painless.
• Angiography: This specialized X-ray assesses blood vessel condition in the legs and feet. A harmless radioactive substance is injected to enhance blood vessel visibility.
• Bone scans: These scans identify bone abnormalities related to diabetes, detecting issues like fractures, tumors, infections, or deterioration. They involve a small injection of radioactive material that highlights areas of bone repair or breakdown.
• Wound classification: Accurate classification of diabetic ulcers is essential for treatment. Wounds are graded based on their stage, from superficial skin involvement to deeper penetration affecting bone. Sensitivity testing and wound cultures may be performed to rule out infections.

Effective management of diabetes-related foot problems requires individuals to monitor blood glucose levels, maintain a balanced diet, engage in regular exercise, and schedule routine physician visits to preemptively address potential issues. Treatment options vary based on the severity and cause of the foot problem, and healthcare providers will discuss suitable options with patients.

Non-surgical treatments for foot problems may include splinting, casting, or bracing to correct deformities. Proper footwear can improve circulation and provide necessary support; custom walking boots may also be recommended. Medications and treatments for infections and skin ulcers may be provided.

The primary aim of surgical intervention is to restore foot integrity and prevent the need for amputation. Surgery may be indicated for severe deformities that cannot be managed through bracing or footwear. In advanced cases, surgery may be necessary to address severe skin ulcers. In extreme situations, surgical amputation of toes, foot, or leg may be required to avert further health complications and protect remaining limb functionality.

Recovery from diabetes-related foot issues varies for each individual, depending on the specific problem and treatment received. Given the progressive nature of these complications, it is crucial to adhere to preventive measures to minimize the risk of further issues and potential amputation.