Dr. Michael E. Edmonds MD FRCP Consultant in Diabetes, King's College Hospital, London, is a world-renowned expert on foot problems in diabetes. He has lectured on the topic throughout the world and gave the inaugural Roger Pecoraro Lecture at the American Diabetes Association's annual meeting. He is also Chairman of the Diabetic Foot Study Group of the European Association of the Study of Diabetes.
Diabetes1: What steps should diabetics take to prevent foot problems? How often should people with diabetes have their feet examined?
Dr. Edmonds: They should have a formal review of their feet annually. The things that should be tested include circulation, their ability to feel sensations, and any abnormal shape in the foot that would make it difficult for them to wear normal shoes. Essentially, based on the assessment from this annual review, it should be decided whether they are at risk for ulcers. If they are at risk for ulcers, then they should be put into a foot protection program, where they should have regular podiatry, education, and follow-up. If they are not at risk for ulceration, then they can still be educated, but they don’t need the close foot protection program and the education is simple common sense measures such as buying well-fitting shoes and looking at their feet to make sure they don’t have any cuts.
Diabetes1: Is a foot exam at the endocrinologist’s or primary care doctor’s office sufficient or should they see a specialist?
Dr. Edmonds: The assessment as to whether they are at risk for ulceration or not can be done by a trained observer that needn’t necessarily be a specialist.
Diabetes1: What is the frequency of foot problems among diabetics and how is it distributed among type 1 and type 2 patients?
Dr. Edmonds: Nerve damage can be present in up to about 50% of diabetics and that can apply to type 1 and type 2. Problems with circulation occur in about 20% to 30% of patients. But probably 15% of diabetic patients over their lifetime will develop ulceration and about 1% could lose their leg.
Diabetes1: What are the most prevalent complications for patients with foot ulcers?
Dr. Edmonds: Infection. Infection is the factor which leads to destruction of the diabetic foot. The mechanism is bacteria entering through the ulcer, invading the foot, and causing severe infection, which then goes on to gangrene.
Diabetes1: How common is infection in people with diabetic foot ulcers?
Dr. Edmonds: Of the people with ulcers about 70-80% will develop infection at any one time. But for the point of view of caring for the patient, you’ve got to assume that 100% will get infections. Once you’ve got a portal of entry, you’ve got a route in for the bacteria and only a few people got away by not getting an infection. The crunch comes in what you do when you have an infection. Some people act early and get good treatment, whereas some people don’t act early and don’t get optimum treatment and then the infection can go to gangrene.
Diabetes1: Can you describe the bone resection procedure for osteomyelitis?
Dr. Edmonds:That procedure is variable. At one end of the spectrum is removing the whole part of the foot that has the infected bone. It may be removing a toe or a toe with a metatarsal head (ray). It may be a mid-foot amputation if there is widespread bone disease. If the disease becomes very widespread, it involves a major amputation below the knee.
Diabetes1: What are the post-operative problems present in patients undergoing bone resection for osteomyelitis?
Dr. Edmonds: Post-operative infections can occur if the original infection has not been eradicated. Recurrent ulceration may occur because the anatomy of the foot is disturbed by taking away a toe. Bone and joint problems occur in patients who have a toe off. Plus the general things such as post-operative chest infections and heart attacks, which are more common in diabetic patients.
Diabetes1: What are the more conservative alternatives for osteomyelitis compared to bone resection? What is their efficacy and in what scenarios should they be used?
Dr. Edmonds: Over the last 10 years, there have been a series of reports indicating that if you give focused, long-term, bone-seeking antibiotics, you can achieve resolution of the osteomyelitis without recourse to surgery. The success rates vary, but there is approximately a 70-80% resolution with antibiotics alone. We initially would try antibiotics and monitor the patient very closely such that if we see progress we will carry on with antibiotics and if there is deterioration then we would resort to surgery. But, it partly depends on the scenario in which you get the bone infection. If you’ve got a scenario where the rest of the foot is severely infected and there is gangrene, then that means surgery. So it’s a spectrum from severe infection with gangrene and bone infection down to mild infection with some degree of bone infection. It’s in the middle of the spectrum that you have to decide whether to go for surgery or antibiotics.
Diabetes1: Can people expect a full recovery from osteomyelitis or is it chronic condition?
Dr. Edmonds:You can expect a full recovery. Usually the osteomyelitis is developed from an ulcer where the bacteria has entered. So the ultimate short-term aim is to cure the osteomyelitis either by chopping the bone out or sterilizing it by antibiotics and to get the overlying ulcer healed. Once that’s healed, the foot is intact, but in the background the patient still has the neuropathy and is prone to recurring ulceration and is still prone to infection. So if you can get a patient healed, follow them up very closely, and they look after their feet very well, then theoretically they won’t get a recurrence. But people do get recurrences.
Diabetes1: What do you envision for the future of diabetic foot medicine? Will light therapy and nitrogen oxide play a greater role or is something else on the horizon?
Dr. Edmonds: The practical issue at the moment is to allow all diabetic patients to have access to multidisciplinary, specialized clinics that will get their ulcers and their osteomyelitis under control. We haven’t in this interview broached the issue of ischemia, but diabetics also have a reduction in blood supply, which has to be dealt with in conjunction with treating the osteomyelitis. Those treatments are given appropriately and early and you get very rapid healing and you can keep these patients free from amputation. So, I think its doing what we say we are doing. In a sense that is the overall umbrella approach. The ultimate aim, of course, is to prevent the neuropathy. If you prevent the neuropathy, then you will prevent all these people from getting ulcers. But there is a limited understanding of neuropathy at the present, so we cannot reverse that. There are new methods to treat ulcers which are ultrasound or radio waves. Those are under investigation. Nitric oxide therapy may be important. Perhaps, if these techniques can be shown to be efficacious, then they will be used aggressively and early to get these patients healed before they have developed infection or osteomyelitis. The first thing is to prevent the neuropathy. The second thing is to prevent the ulcer. Thirdly, is to heal the ulcer quickly to prevent infection. Finally, is to treat the infection aggressively before they get gangrene and need amputation.
Dr. Edmonds is also the author of numerous research articles and books on the care of the diabetic foot, including the 'Practical Manual of Diabetic Foot Care'.