Diabetic Foot Ulcers – “Good thing I can’t feel it!”
Courtesy Physician Wound Care Specialists of Utah, Salt Lake City LIVING WELL Magazine
Non-healing diabetic foot ulcers are the top cause of surgical amputations, with 80,000 Americans loosing a leg each year. About 50% develop an ulcer on the remaining foot within 18 months, and nearly 60% will have the remaining leg amputated within three to five years. Despite significant treatment advances over the past 30 years, these alarming statistics have changed little.
Among a larger list, the three more significant problems contributing to development of diabetic foot ulcers are: 1) Neuropathy; 2) Peripheral arterial disease; 3) Joint deformity/immobility. Each will be expanded here to help motivate and educate the reader toward prevention of a problem ulcer.
The most important contributor to onset of foot ulcers is loss of protective sensation (neuropathy). “Insensate” feet are 10 times more likely to develop an ulcer. Exactly how diabetic neuropathy develops is not thoroughly understood. One theory is that elevated blood sugars damage micro-vessels that supply nerves with oxygen and nutrients. Deprived of nourishment, the nerves gradually deteriorate. Without normal feedback, the brain does not detect when the foot is subjected to trauma from a sharp object, or excessive friction or pressure from shoes, bare feet on floors, etc.
Poor circulation is another factor influencing both development of an ulcer as well as that ulcers’ ability to heal. Peripheral arterial disease (PAD) is a gradual narrowing of arteries (atherosclerosis) in the legs. Diabetes is a major contributor to PAD, in addition to atherosclerosis in other parts of the body. Other conditions and habits also contribute to PAD such as high cholesterol, high blood pressure and smoking. PAD is a macro-vascular process of larger arteries and can often be improved with surgical bypass or less invasive stent placements. Unfortunately, diabetes also causes a micro-vascular disease that can affect multiple locations to include the superficial tissues of the feet, as well as the eyes (diabetic retinopathy), and the kidneys (diabetic nephropathy). Even in the absence of PAD, many diabetics struggle to heal foot ulcers because micro-vascular disease reduces delivery of oxygen and nutrients to the wounded tissues. Besides hyperbaric oxygen therapy, there is no known treatment to improve micro-vascular disease.
Diabetes can indirectly lead to foot deformation and rigidity. As noted above, neuropathy often develops from diabetes affecting the small blood vessels. Three types of nerves are affected: sensory, autonomic and motor nerves. When motor nerves are diseased, muscles will weaken or atrophy. Reduced muscle integrity combined with the forces of body weight acting on the feet, contribute to joint deformation. This process is most often slow and imperceptible to most individuals. A problem of this type known as Charcot deformity, develops when multiple joints within the arch become acutely inflamed. The joint damage can cause collapse and fusion of the arch such that the foot develops more of a reverse arch or rocker bottom. This large, inflexible mass of bone makes the soul of the foot very susceptible to ulceration.
Most diabetics remain unaware that one or more of the above problems are occurring until an inciting event causes a foot wound or ulcer. For these reasons, everybody with diabetes should learn to properly examine their feet to watch for early warning signs. Preventive foot exams and toenail care by a trained professional is recommended every three to six months. Not all primary care clinicians do this, so ask yours about seeing a good foot specialist for routine diabetic foot care. They can determine if the above-mentioned processes have begun and recommend the best preventive measures for you.
If a foot ulcer does occur, regardless of size or location, it is no simple matter! There is little tissue between skin and bone on many foot surfaces, therefore bone infections (osteomyelitis) can develop more quickly than in other body parts. Reduced blood flow from micro-vascular disease impacts this issue as well. The majority of our immune system resides within blood; therefore, when flow is reduced, so is the ability to fight off infection. The two reasons for leg amputations in diabetics are osteomyelitis and soft tissue gangrene associated with infection and/or PAD. Rapid healing of a diabetic ulcer is very challenging because multiple issues must be managed well simultaneously, over many weeks to achieve this. Keeping pressure off an ulcer at all times, while maintaining normal activities of daily living, is one of the greatest challenges on the list. If a foot ulcer develops, please seek out expert help – because if it does not turn out well, you have a lot to lose!
For more expert information, contact Physician Wound Care Specialists of Utah, located on the 3rd floor of St. Mark’s Hospital, above the Emergency Room, 1220 E. 3900 S, Suite 3A, Salt Lake City, 84124, call 801-272-0355, or visit www.pwcsu.com.
