Clinical Presentation
Diabetic ulcers can be quite problematic. It is not uncommon for people with diabetes who have developed forefoot ulcers to ultimately end up with a partial or complete amputation of their foot stemming from the type of infection that can occur with a diabetic ulcer.
Patients with longstanding diabetes who have lost sensation or have altered sensation in their foot are risked for developing a diabetic plantar ulceration. Quite often, patients with diabetes do not appreciate that they have altered sensation in their foot. The altered sensation prevents them from sensing pain such as they would normally experience with a blister on their foot or with shoes that do not fit appropriately. They, therefore, end up with blistering and subsequent breakdown over a localized pressure area of the foot and this can become an ulcer. Often, the area starts off as a callus or if it occurs quickly, it may appear as a simple blister. However, when the blistered skin is removed, it will reveal a deep ulceration.
Physical Examination
Physical examination focuses on the location of the ulcer as well as the depth. It is important to assess whether or not the ulcer extends down to the bone, which could lead to osteomyelitis (bone infection). Typically, the ulcers will occur over a prominent area often associated with the base of one or more toes, although ulcers in other areas can occur. An assessment of the patient’s sensation is also important. Essentially any area of the foot, which is subject to concentrated repetitive force either because there is a prominent area there or because the calf muscle has stiffened and is serving to increase the lever force of the foot driving the forefoot into the ground with more force. It is important on physical exam to also assess the patient’s opposite foot as this may have problems that have not yet been diagnosed.
Imaging Studies
Radiographs will usually be taken to assess whether there is any obvious bony involvement. Sometimes, an MRI is indicated to look for extension of the soft tissue infection if this cannot be determined clinically. Occasionally, a bone scan is indicated, although very often the results of the bone scan will not change the management and may not reveal any information that cannot be obtained from a detailed physical examination.
Treatment
Treatment is designed to allow the ulceration to resolve. Essentially, this involves off loading the ulceration. This is typically done with a total contact cast. It may be possible to fit the patient with a diabetic removal Cam boot. In each instance, the goals are to off load the affected area and allow the tissues to heal. If this is done, it will often allow the ulceration to heal within 6-8 weeks for a full-blown ulceration.
The patients that are at risk for ulcerations, but have not yet developed full diabetic ulceration. It may be treated with inserts that are designed to disperse the force away from the affected area. These inserts are typically made of Plastizote, which is a substance that accommodates to the forces that it is subject to. It, therefore, takes on the shape of the foot and helps to spread the force away from the ulcerated area.
Patient education is a very important component of managing diabetic ulcerations. Ideally, ulcerations should be treated with prevention. Patients with diabetes and particularly those who had altered sensation in their feet should be very cognizant of always wearing appropriate shoe wear. They should also check the soles of their feet daily to look for any potential skin breakdowns or new blister formation, as well, by always wearing shoes that will allow them to avoid walking on hot surfaces, which is another way by which patients will have a breakdown in the skin over the sole of their feet. Finally, they should have regular foot checkups and should keep their toenails well trimmed. This typically involves keeping the toes trimmed either straight across or with a gentle contour in the shape of the toe and ensuring that the inside and outside edges of the toenails do not catch and jab into the associated skin.
Treatment of the ulceration may also involve debridement of the callus or necrotic tissue. Usually, this can be done in the clinic, although sometimes it may need to be done in the operating room if the infection involves the bone and there is some need to remove part of the involved bone. In addition, it is increasingly common to perform a calf lengthening or Achilles tendon lengthening to help decrease the load that the forefoot is experiencing. This can be highly successful, although it does need to be done with caution to prevent over lengthening. This is done as a formal operative procedure.
Patients with diabetes and altered sensation of their feet who notice a breakdown in the skin should see a physician immediately. The physician may want to prescribe antibiotics or they may consider this such that simply off loading this area for short period of time will help resolve the skin breakdown. Small breakdowns in the skin can become major limbthreatening problems in a matter of days if they are not carefully attended to.
