Arthritis in the Foot
A wound is an injury in which the skin is torn, cut or punctured (an open wound), or where blunt force trauma causes a contusion (a closed wound). In pathology, it specifically refers to a sharp injury which damages the dermis of the skin.
Wounds can occur from any multiple of reasons. They can be from sports injuries, where the athlete has had their foot injured by a hard contact with something. In some professions accidents occur where a sharp object has penetrated into the foot. However, most common wounds the Podiatrist treats are diabetic foot ulcers.
The vast majority of chronic wounds can be classified into these categories: venous ulcers, arterial wounds, diabetic and pressure ulcers.
Venous and Arterial Ulcers
Venous ulcers, which usually occur in the legs, account for about 70% to 90% of chronic wounds and mostly affect the elderly. They are thought to be due to venous hypertension caused by improper function of valves that exist in the veins to prevent blood from flowing backward. The result can be tissue damage that leads to the wounds.
Another major cause of chronic wounds, diabetes, is increasing in prevalence. Diabetics have a 15% higher risk for amputation than the general population due to chronic ulcers. Diabetes causes neuropathy, which inhibits nociception and the perception of pain. Thus patients may not initially notice small wounds to legs and feet, and may therefore fail to prevent infection or repeated injury. Further, diabetes causes immune compromise and damage to small blood vessels, preventing adequate oxygenation of tissue, which can cause chronic wounds. Pressure also plays a role in the formation of diabetic ulcers.
Another leading type of chronic wounds is pressure ulcers, which usually occur in people with conditions such as paralysis that inhibit movement of body parts that are commonly subjected to pressure such as the heels, shoulder blades, and sacrum. Pressure ulcers are caused by ischemia that occurs when pressure on the tissue is greater than the pressure in capillaries, and thus restricts blood flow into the area. Muscle tissue, which needs more oxygen and nutrients than skin does, shows the worst effects from prolonged pressure.
Though treatment of the different chronic wound types varies slightly, appropriate treatment seeks to address the problems at the root of chronic wounds, including ischemia, bacterial load, and imbalance of proteases. Various methods exist to ameliorate these problems, including antibiotic and antibacterial use, debridement, irrigation, vacuum-assisted closure, warming, oxygenation, moist wound healing, removing mechanical stress, and adding cells or other materials to secrete or enhance levels of healing factors. Some treatment methods are listed below.
Most venous ulcers respond to a regimen called Bisgaard regimen for treating ulcers. Best remembered as a 4E’s – education, elevation, elastic compression and evaluation.
Non-elastic, ambulatory, below knee compression aggressively counters the impact of reflux on venous pump failure. Compression therapy is used for venous leg ulcers and can decrease blood vessel diameter and pressure, which increases their effectiveness, preventing blood from flowing backwards. Compression is applied using elastic bandages or boots specifically designed for the purpose. Patients should wear as much compression as is comfortable.
This medication is used to improve the symptoms of a certain blood flow problem in the legs/arms. It works by helping blood flow more easily through narrowed arteries. This increases the amount of oxygen that can be delivered by the blood when the muscles need more (such as during exercise) thereby increasing walking distance and duration.
Artificial skin, made of collagen and cultured skin cells, is also used to cover venous ulcers and excrete growth factors to help them heal. One study indicated that Bilayer artificial skin, used in conjunction with compression bandaging, increases the chance of healing a venous ulcer compared with compression and a simple dressing”.
Surgical Correction of Superficial Venous Reflux
A randomized controlled trial found that surgery “reduces the recurrence of ulcers at four years and results in a greater proportion of ulcer free time”.
Developed by Dr. Ronald Bush, the TIRS (Terminal Interruption of Reflux Source) Technique entails blocking off the veins that drain the ulcer bed using Sotradecol or Polidocanol foam, administered by ultrasound guidance.
Diabetic Foot Ulcer
Diabetic foot ulcer is one of the major complications of diabetes. It occurs in 15% of all patients with diabetes and precedes 84% of all lower leg amputations. Being a natural phenomenon, wound healing is usually taken care of by the body’s innate mechanism of action that works reliably most of the time.
But in some cases, certain disorders or physiological problems disturb the wound healing process that otherwise goes very smoothly in an orderly manner. Diabetes mellitus is one such metabolic disorder that impedes normal steps of wound healing process.
Treatment: It is a common trend in diabetic foot care domain to use advanced moist wound therapy, bio-engineered tissue or skin substitute, growth factors & negative pressure wound therapy. No therapy is perfect as each type suffers from its own disadvantages. Dr. Shumate will determine which therapy would be best for your situation.
Prevention: Prevention is by having regular check-ups by Dr. Shumate, good foot hygiene, if diabetic, using diabetic socks & shoes, and avoiding injury.
All major reviews recommend special footwear for patients with a prior ulcer or with foot deformities. One review added neuropathy as an indication for special footwear.
* See topic of Diabetes under Foot Problems in this website for further reading.