Prevention Key to Limb Salvage

Robert Frykberg, DPM, MPH PRESENT Editor, Diabetic Limb Salvage

PREVENTION:The Key to Limb Salvage

Over the last two and one half decades, it has become quite clear that Prevention of diabetic foot wounds is the key to avoiding diabetic limb loss. As early as 1986, Edmonds et al. published their study in the Quarterly Journal of Medicine showing that a Multidisciplinary Clinic focused on early intervention, education, and preventive foot care (including footwear) significantly improved rates of recidivism and limb loss.¹   Numerous other studies in subsequent years have confirmed these findings.^2-6  As we previously discussed in our FootNotes issue dealing with Diabetic Foot Ulcers,²⁴ Pecoraro in 1990 demonstrated that nonhealing diabetic foot wounds were one of the most common component causes in the causal pathway leading to lower limb amputations in this population.⁷   In the setting of neuropathy with loss of protective sensation (LOPS), therefore, any diabetic foot wound poses a serious threat to the well-being of such persons. As Pecoraro also found, eighty-five percent of the diabetes related lower limb amputations occurred subsequent to these non-healing foot ulcers. Thankfully, this does not imply that 85% of foot ulcers go on to amputation! The true percentage most likely lies in the range of 15-20% or so, based on two other important studies.^8,9   The important point here is that diabetic foot ulcers (DFU) are a serious complication of the disease and, once present, potentially place the patients’ limb at risk. Equally important, several studies have shown that DFUs also impart a decreased survival risk for these patients when compared not only to non-diabetic persons, but to persons with diabetes without a history of ulceration.^8,10-12 I can refer you to Jarrod Shapiro’s Practice Perfect ezine, A Practice Perfect Podiatric Service Announcement,²⁵ wherein he discussed the morbidity of diabetic lower extremity complications and the role of prevention.

I believe that a Diabetic Foot Prevention Program is not only effective, but should also be amandatory part of the management of High Risk patients. Although primary prevention of limb threatening problems is not always possible, secondary and tertiary prevention of the recurrence or progression of the disease certainly should be practiced.¹³ Hence, we have seen the development of Risk Stratification  schemes from the International Working Group on the Diabetic Foot and from the Veterans Affairs system.^14,15 The purpose, of course, is to stratify diabetic patients according to their risk for ulcers and amputations; subsequently, the level of risk is used to determine frequency of care, self foot care, and the need for protective “therapeutic “ footwear. In the VA, we have certainly seen a dramatic reduction in the rates of major amputation in the last decade, since fully implementing our Amputation Prevention Program in concert with a close collaboration with our Vascular Surgery colleagues. We cannot save limbs without aggressive detection and treatment of underlying critical ischemia. Figure 1 clearly illustrates this trend for the diabetic population.

Figure 1. VA amputation rates (diabetes only) (Courtesy Department of Veterans Affairs)

Commensurate with the decrease in major amputations, there has been an increase in the number of limb salvaging minor (foot level) amputations. The High/low or major/minor ratio is the best indicator for success in this regard, wherein the smaller the ratio, the better.¹⁶   Figure 2 shows the major/minor ratios over the last decade as well, with a very nice decline as the number of minor amputations far surpasses the number of major amputations.

Figure 2. Major/minor ratio (VA diabetes cohort) (Courtesy Department of Veterans Affairs)

5 Ps of Prevention

There are five primary areas that are essential to any foot care program designed to prevent lower extremity amputations. (Table 1)  These were first reported over a decade ago and still hold true.¹⁷

1). Podiatric Care  can be practiced by any foot care specialist interested in management of high risk patients. Such care involves not only regular foot care visits and management of acute or chronic foot problems, but also serves to detect impending problems at their earliest onset. Foot care providers, most commonly podiatrists in the USA, see their patients fairly frequently depending upon their level of risk as mentioned above.

2). Protective or “therapeutic” footwear is considered to be a mainstay of preventive therapy for high risk patients, although there have been conflicting reports on the efficacy of therapeutic shoes.^18-20  Nonetheless, it just makes good sense to wear appropriate footwear when a patient has neuropathy, PAD,  or a history of ulcers or amputations.  In addition to protective footwear, good care also includes.

3). Pressure reducing insoles. These can include simple high quality insoles or custom molded multidensity insoles for feet with deformity or documented high pressures. In this regard, plantar pressure assessments can be made with pressure sensitive contact mats (Pressure Stat®)  or computerized analysis systems (Tekscan®).

4). Prophylactic Surgery or reconstructive surgery in diabetic neuropathic patients is now considered to be an important component in the care delivered to persons with deformity and recurrent foot ulcerations. It has been sometimes termed as “surgical offloading” or internal decompression of high pressures caused by bony deformities.²¹ Obviously, patients must be appropriately evaluated and intervention must occur at an opportune time, unless surgery is needed emergently.

5). Patient and Provider Education is critical for success and has been shown to have a positive impact in reducing ulcer recidivism and the need for amputations.^1-5 Patients need to be educated about diabetes management and proper foot care at every encounter. Providers need to be educated about risk factors and their modification, new treatment modalities, as well as emerging principles for care.

An amputation prevention program is not difficult to develop; it just takes a dedicated team of professionals to accomplish the goal.^13,17,22 The key word is TEAM. All interested providers are needed, since all have unique talents and experiences. Figure 3 represents my concept of a fully functioning multidisciplinary team. The literature is replete with evidence supporting such a framework and the commensurate reduction in amputations.^6,13,23 I challenge those of you interested in high risk patients to develop or join such established teams. Although it takes a good deal of time and dedication, the rewards can be not only limb salvaging, but life saving!

Figure 3. Multidisciplinary Framework for an Amputation Prevention Team.

References are provided below that can expand upon many of the points made above. We welcome your opinions, concerns, and suggestions.  If you have an interesting case or a troubling circumstance that you would like to share with fellow PRESENT Diabetes members,  please feel free to comment on eTalk.

Best regards,

Robert Frykberg, DPM, MPH
PRESENT Editor,
Diabetic Limb Salvage

REFERENCES