Reassessing The Impact Of Diabetic Footwear

Many sources in the literature describe the presence of pedal deformity and recurrent ulcerations associated with diabetes mellitus.1-4 Establishing a multidisciplinary team of physicians is essential for avoiding complications among these patients with diabetes.5,6 Unfortunately, the pedorthotist/orthotist is a frequently underutilized member of this team. Indeed, certified CPeds can make the difference between success and failure of diabetic limb salvage and ulcer prevention. Certainly, the importance and impact of diabetic footwear cannot be ignored as a key component in managing patients with diabetes. Given their knowledge of functional and accommodative devices, braces and orthoses for offloading the foot, pedorthotists/orthotists can play a valuable role in preventing reulceration after conservative cure or in providing stability and protection to a limb after extensive surgical limb salvage.7 The CPed can also assist patients who have undergone an amputation. Pedorthotists can make prosthetic devices for these patients and aid them in following through with their rehabilitation. Our pedorthotist/orthotist is able to provide in-office service for individuals who are unable to travel to and from their facility. When it comes to using proper footgear and bracing, each patient has different needs with uniquely different pathology.8,9 Some people may need custom devices due to gross deformation of the foot. Others may need special materials to cushion, prevent friction, and/or offload prominent bony areas of the foot. In order to effectively minimize or prevent injury, one must determine the presence or absence of protective levels of sensation.10 Other risk factors for ulceration in patients with diabetes include: a duration of diabetes for more than 10 years; poor blood sugar control; male gender; foot deformity; soft tissue contractures and intrinsic muscle atrophy causing increased plantar pressures; and amputation.11-13 A Guide To Risk Categories Of The Diabetic Foot For a breakdown of the risk categories of the diabetic foot, see the table “Risk Categories And Management Of Diabetic Patients With Foot Ulcers” below.14 Identifying the level of pathology is essential for determining an appropriate course of treatment. • Risk category 0 represents patients who have been diagnosed with diabetes but have intact protective sensation, no history of ulceration and no gross foot deformity. Appropriate management of this patient should include extensive patient education, proper footwear and a follow-up visit at least every 12 months. • Risk category 1 represents the patient who has a loss of protective sensation, but has no history of ulceration or gross deformities of the foot. The pedal pulses may or may not be diminished. Appropriate management of this patient should include podiatric visits every three to six months, extensive evaluation of footwear and liners, extensive patient education and observation of compliance issues such as glucose control (record keeping), weight loss and foot hygiene. One should perform a baseline non-invasive vascular exam if pedal pulses are diminished. • Risk category 2 represents those who have much more risk for potential serious problems. These patients have no protective sensation. They may or may not have a history of plantar ulceration but they do have a deformity of the foot. Deformities in this stage may include digital contractures, equinus, thinning of the plantar substance of the foot (intrinsic muscle atrophy), and cutaneous changes you would see with varying amounts of vascular depletion. Appropriate management of these patients usually requires clinic visits as often as every one to three months, custom molded liners in extra-depth shoes (or custom molded shoes in the presence of gross structural changes), extensive education and consults with appropriate specialists. • Risk category 3 represents neuropathic patients with a history of plantar ulcerations, more severe contractures and deformity, and varying levels of vascular compromise. These patients may start showing more gross deformities associated with Charcot neuroarthropathy. Management of these patients may require involvement with a vascular surgeon, followed by addressing any plantar prominences or soft tissue contractures causing ulceration. Clinic visits may vary from every two weeks to two months. Close evaluation and management with an endocrinologist and/or cardiologist is favorable. We also believe there should be a Risk category 4. This category would represent those patients who have an unstable and insensate diabetic Charcot foot with a long history of ulcerations and failed conservative prosthetic intervention. These patients would require surgical intervention for limb salvage. They are usually long-term, noncompliant diabetics who have severe neuropathy (often proximal to the knee) and vascular compromise that requires vascular surgical intervention. The patients will also tend to have multiple and severe comorbid conditions including congestive heart failure, coronary artery disease, and end-stage renal disease, often qualifying as ASA category 3 or 4 for anesthesia. Managing these patients is a complex and extensive process. Many who are worked up in preparation for surgery become non-surgical candidates and are left with the alternatives of having a poor quality of life or undergoing a major amputation with a poor prognosis with morbidity and mortality. An Overview Of Diabetic Footwear Options Unfortunately, when it comes to managing patients with diabetes, proper shoe gear and bracing are often underutilized. Obtaining a consult with a reliable pedorthotist/orthotist will help produce reliable and reproducible results in managing diabetic foot pathologies. There are many types of footwear, orthoses, prosthetics and adjunctive devices. The art behind the science of fitting diabetic individuals into the appropriate combination of devices is highly individualized. The majority of devices used include: • extra-depth shoes with custom molded liners; • custom molded shoes/liners; • custom molded/extra-depth shoes with ankle-foot-orthoses (AFO); • the Charcot Restraint Orthotic Walker (CROW); • a patellar weightbearing ambulatory device (PTB); • the Gauntlet Brace; • the Ischial Weight Bearing Ambulatory Walker (ICB); and • a variety of prosthetic limbs and fillers. When Are Therapeutic Shoes Indicated? Extra-depth shoes with custom molded liners are ideal for those patients who have a history of ulceration or those who have propulsive or apropulsive gait patterns with a decreased fat pad. One can also prescribe these shoes for patients who have had successful reconstructive surgery and have a relatively stable and anatomically “normal” foot type. In regard to custom molded shoes/liners, they work very well for patients who have gross anatomic changes of the foot that are stable. They are also effective for patients who have grossly misshapen feet that are stable but are not able to undergo surgical reconstruction. One can also combine custom molded shoes with an AFO for patients who have had a tibiocalcaneal arthrodesis and require gradual protection as they progress and transition into shoes. Keep in mind that the foot to leg relationship must be relatively stable in order for this combination to be beneficial for the patient. What You Should Know About The CROW And PTB Braces The Charcot Restraint Orthotic Walker (CROW) is structurally much more complex than any shoe. This device is custom molded and handmade. The CROW is designed to offload the foot in a similar fashion to a total contact cast (TCC). Indications for a CROW include: offloading an open ulcer; stability and offloading of an unstable Charcot foot/ankle for a non-surgical patient; and post-surgical protection and transition following foot and ankle reconstruction for diabetic patients. When the CROW brace is properly constructed, it can decrease plantar forefoot and midfoot pressures by approximately 50 percent.7,9 A patellar weightbearing brace (PTB) is similar to that of a CROW but is more efficient at offloading the unstable foot, the hot Charcot foot or any plantar ulcer. One can achieve up to a 90 percent reduction in plantar pressures with a properly constructed patellar weightbearing device. When it is properly indicated, this device could become a mainstay in offloading the diabetic foot. Be advised that patient compliance can be a problem with both the CROW and PTB. Patients with moderate to severe edema may not be able to remove these devices and other patients may not be able to put them on properly. When Other Braces Can Be Effective A pedorthotist can creatively make a brace to help a patient ambulate more effectively in cases of distal tibial fractures or when surgically corrected fractures require a significantly longer duration of nonweightbearing. One can employ a Gauntlet brace to help transition a patient from a cast to a state of ambulation. In our experience, there have been many cases when a pedorthotist’s creativity has helped our patients. Bear in mind that the potential complications associated with the Gauntlet brace include contact dermatitis, skin abrasion and ulceration in obese patients. When you are dealing with severe edema, an unstable knee or morbidly obese patients who require offloading of the foot, you may want to consider the Ischial Weightbearing Ambulatory Walker (ICB). A more aggressive option, this device is effective when the only other option is non-ambulation in a wheelchair. The device allows motion at the knee with a hinge and transfers the majority of the weight from the foot to the leg, thigh and ischial tuberosity. This device requires precise construction by an experienced pedorthotist. Disadvantages of this device include skin slough, pressure ulcers and awkward gait. Pertinent Suggestions For Accommodating Patients Who Undergo Amputations In caring for patients with diabetes, one should have a firm grasp of the indications for managing prosthetic limbs. The orthopedic community has published many reports that a below knee amputation has the best results for prosthetic use.15 Unfortunately, amputation involving the diabetic limbs has an enormous effect on the quality of life, morbidity and mortality in a relatively short period of time. Studies show five-year mortality rates of diabetic populations following a below knee amputation to be as high as 70 percent.16 Other possibilities for amputations include transmetatarsal, LisFranc’s, Chopart’s and Symes amputations.16,17 One can accommodate transmetatarsal, LisFranc’s and Chopart amputations with shoes and appropriate fillers. When one combines a modified PTB with a prosthetic foot for postoperative use, the Symes amputation can be very beneficial in maintaining patient ambulation. This device is visually appealing to the patient and facilitates a short transition time for the patient in adjusting to an ambulatory status. Possible complications with the Symes amputation and the use of a prosthetic brace include patient compliance and proper application of the brace to the leg. If the brace is not applied properly, there may be an increase in excessive pressures to the distal stump. This may result in displacement of the distal fat pad and/or ulceration, leading to further surgical intervention. Final Notes Setting aside the obvious notion that better patient education coupled with early intervention can prevent or minimize the level of amputation, using a properly constructed device is essential to prevent further complication in the diabetic foot. Properly fitted shoes, whether they are custom molded or prefabricated with the appropriate liner, help prevent the recurrence of further breakdown. When amputation is unavoidable, one can still prevent further development of new pathology by following up the treatment with the appropriate shoe, filler, bracing and prosthetic. Developing a trusting relationship with a reliable, certified pedorthotist is essential for all clinicians who care for the diabetic foot. Dr. Pupp is the Clinical Director of the Kern Hospital Foot and Ankle Clinic in Warren, Mich. He is a Fellow of the American College of Foot and Ankle Surgeons and is also the Clinic Director at the Sinai Grace Diabetic Foot Center in Detroit. Dr. Wilusz is a third-year surgical fellow at the Kern Hospital Foot and Ankle Clinic in Warren, Mich. He has had extensive training in diabetic limb salvage and rearfoot reconstructive surgery.
 

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References 1. Bailey, TS, Yu HM, Rayfield EJ: Patterns of Foot Inspection in a Diabetic Clinic. Am J Med 78:371, 1985. 2. Caputo GM, Cavanagh PR, Ulbrecht US, et al: Current Concepts: Assessment and Management of Foot Disease in Patients with Diabetes. N Eng J Med 331:854-860, 1994. 3. Consensus Development Conference on Diabetic Foot Wound Care: Diabetes Care 22:1354-1360, 1999. 4. Delbridge L, Appleburg M, Reeve TS: Factors associated with the development of foot lesions in the diabetic. Surgery 93:78, 1983. 5. Moss SE, Klein R, Klein BE: The prevalence and incidence of lower extremity amputation in the diabetic population. Arch Intern Med 152:610-616, 1992. 6. Mayfield JA, Reiber GE, Sanders LJ, et al: Preventive foot care in people with diabetes (technical review). Diabetes Care 21:2161-2177, 1998. 7. Interview: John Bryant, CPO, ABC. 8. Chantelau E, Haage P: An audit of cushioned diabetic footwear: Relation to patient compliance. Diabetic Med 10:114, 1993. 9. Cterceko GC, Dhanendran MK, Hutton WC et al: Vertical forces acting on the feet on diabetic patients with neuropathic ulcerations. Br J Surg 68:608, 1981. 10. Clements RS, Bell DS: Diabetic neuropathy: Peripheral and autonomic syndromes. Postgrad Med 71:50-52, 55-57, 60-67, 1982. 11. Armstromg, DG, Lavery LA, Harkless LB: Treatment based classification system for assessment and care of diabetic feet. J Am Podiatr Med Assoc 86:311-316, 1996. 12. Grunfeld C: Diabetic foot ulcers: Etiology, treatment, and prevention. Adv Intern Med 37:103-132, 1992. 13. Feldman EL, Stevens MJ, Greene DA: Pathogenesis of Diabetic neuropathy. Clin Neurosci 4:365-370, 1997. 14. Bowker JH, Pfeifer AP: Levin and O’Neal’s The Diabetic Foot; Sixth Edition. Pages 425-428, 2001. 15. Tooms RE. Campbell’s Operative Orthopedics, 9th Edition. Chapter 10. 1999. 16. Ecker ML, Jacobs BS: Lower extremity amputations in diabetic patients. Diabetes 19:189-195, 1970. 17. Armstrong DG, Lavery LA, Harkless LB, Van Houtum WH: Amputation and re-amputation of the diabetic foot. J Am Podiatr Med Assoc 87:255-259, 1997.