An Overview of the Management of Diabetic Foot Ulcers
Davern R1, Hatunic M1, 2
1Department of Endocrinology, Mater Misericordiae University Hospital, Dublin, Ireland
2Medical School, University College Dublin, Dublin, Ireland
Lower extremity ulceration is the most common complication encountered clinically and has predicted 1-2% prevalence amongst US adults1 and an annual incidence of 2.2% in the UK2. The lifetime incidence of foot ulceration in persons with diabetes has been estimated at 15-25%3. This increase in foot ulceration is associated with increasing rates of infection4 and amputation5. The 5-year mortality in patients with diabetes and critical limb ischaemia is 30% and about 50% of patients with diabetic foot infections who have foot amputations die within five years which, put in perspective, is worse than some forms of cancer6. In Ireland, there were 1,297 hospital discharges for people with diabetes for foot ulceration without amputations in 2008 and 337 discharges for people with diabetes who had a lower limb amputation. This amounted to 23,601 bed days per year used for diabetics with lower limb ulcers and 11,622 bed days per year used for diabetics with lower limb amputations7.
The pathological processes that lead to diabetic foot ulceration are multifactorial, with arterial insufficiency and neuropathy both playing a major role. These two defects combined promote foot injury and subsequent ulcer formation. Diabetic ulcers are broadly divided into neuropathic ulcers and neuroischaemic ulcers. On examination, the neuropathic foot will be warm with palpable pulses but sweating is diminished. Ulcers tend to occur on the plantar aspect of the foot and toes. In contrast, the neuroischaemic foot will be cold with poor pulses and hairless. Neuroischaemic ulcers are often seen on the margins of the foot, especially on the medial surface of the first metatarsophalangeal joint and over the lateral aspect of the fifth metatarsophalangeal joint. Neuropathy in the lower limb can lead to the development of Charcot foot. Charcot joint refers to the accelerated degenerative changes and ultimate joint destruction that follows repetitive trauma to insensitive, neuropathic joints. Although diabetes is not the only cause of a Charcot foot it is by far the most common.
Healthcare physicians should use any consultation with diabetic patients as an opportunity for examination of their lower extremities. The International Working Group on the Diabetic Foot (IWGDF) recommends annual foot examination for diabetics with no peripheral neuropathy, 6 monthly for those with peripheral neuropathy, 3-6 monthly for those with neuropathy, peripheral arterial disease and/or foot deformity and 1-3 monthly in those with previous amputation8. An examination with monofilament and vibration fork is recommended to assess the level of sensation present in the patient’s lower limbs. Then an assessment must be done to determine if there is any concurrent infection9. This is of major clinical importance as one in five patients with an infected foot ulcer will undergo amputation10. This assessment should involve examining for warmth, tenderness, erythema, swelling and purulent discharge. If the ulcer is deep and overlies bone, osteomyelitis should be considered and initial investigations with plain radiography and MRI, which is more sensitive11.
Successful management of lower extremity complications in diabetics requires an extensive MDT input. Firstly, lifestyle factors need to be addressed to prevent recurrent ulceration. It should be emphasised to patients that meticulous footcare is the cornerstone of treatment. Other lifestyle adjustments include smoking cessation and the use of well-fitted footwear. It has been shown that patient education given over one to two sessions does not prevent ulcer recurrence at the 6 to 12 month mark12. Ill-fitting footwear has been identified as a risk factor for ulcer formation13. Hence why properly fitted footwear – neither too tight nor too loose, with the inside of the shoe being one to two centimetres longer than the foot, is important to prevent ulcer formation and ulcer recurrence. Unfortunately, adherence to lifestyle modifications, especially therapeutic footwear, can be poor. Many RCTs have shown that those patients who follow recommendations have much better outcomes than those who do not14,15. Wound dressings are used to protect the ulcerated area from further injury. There are many types of dressings available and, in general, dry wounds are treated with moisture promoting dressings whereas exudative wounds are managed with absorptive dressings.
Following on from lifestyle changes, surgical debridement is helpful in removing dead tissue and reducing the bacterial burden16. A systematic review of 45 randomised controlled trials showed no evidence to support prophylactic systemic antibiotics for lower limb ulcers17. If there is clinical suspicion of infection swabs should be sent and systemic antibiotic cover for gram positive and gram negative bacteria along with anaerobes should be used. Potential combinations would include penicillin and a beta lactamase inhibitor or fluoroquinolone or linezolid alone.
Several newer surgical procedures have been evaluated. Digital flexor tenotomy has been shown to be effective in several retrospective case series. This data showed that in 58 patients with impending ulcer formation, no ulcer was found at the 11-31 month follow up18,19,20,21. For the prevention of recurrent ulcer formation, Achilles tendon lengthening, joint arthroplasty, single or pan metatarsal head resection, or osteotomy have all been evaluated. Achilles tendon lengthening has been shown in one randomised control trial22 and several non-controlled studies23,24,25,26 to be effective in preventing ulcer recurrence in both the long and short term. There are fewer studies looking at joint arthroplasty but they have shown lower ulcer recurrence rates27,28,29. One retrospective cohort study showed a non-significant reduction in ulcer recurrence30. It must be taken into account that all surgical procedures carry risks and complications.
Recent publication in NEJM31 showed unfortunately that after the resolution of a foot ulcer, recurrence is common. The incidence rates for ulcer recurrence was estimate that roughly 40% of patients have a recurrence within one year after ulcer healing, almost 60% within three years, and 65% within 5 years. The authors in this paper31 summarised that once healed, foot ulcers frequently recur. This fact, coupled with demographic trends, requires a collective refocusing on prevention and a reallocation of resources from simply healing active ulcers to maximizing ulcer-free days for all patients with a history of diabetic foot ulceration.
In conclusion, lower extremity ulcers are significant problems for diabetic patients. Once healed, ulcers tend to recur. Aggressive early intervention is required to reduce the significant morbidity, mortality and hospital admissions associated with diabetic foot ulcers.
Dr Mensud Hatunic, Consultant Endocrinologist Department of Endocrinology, Mater Misericordiae University Hospital, Dublin, Ireland
1. Alavi A, Sibbald RG, Phillips TJ. What’s new: management of venous leg ulcers: approach to venous leg ulcers. J Am Acad Dermatol 2016;74:627640
2. Abbott CA, Carrington AL, Ashe H. The North-West Diabetes Foot Care Study: incidence of, and risk factors for, new diabetic foot ulceration in a community-based patient cohort. Diabet Med 2002; 19: 377-84.
3. Singh N, Armstrong DG, Lipsky BA. Preventing foot ulcers in patients with diabetes. JAMA 2005; 293: 217-28.
4. Prompers L, Huijberts M, Apelqvist J. High prevalence of ischaemia, infection and serious comorbidity in patients with diabetic foot disease in Europe: baseline results from the Eurodiale study. Diabetologia 2007; 50: 1825.
5. Lipsky BA, Berendt AR, Cornia PB. 2012 Infectious Diseases Society of America clinical practice guideline for the diagnosis and treatment of diabetic foot infections. Clin Infect Dis 2012; 54(12):e132-e173.
6. Weledji, Treatment of diabetic foot to amputate or not? BMC Surg
7. National Diabetes Programme Working Group. Model of care for the diabetic foot. Dublin: HSE; 2011.
8. K. Bakker1, J. Apelqvist2, B. A. Lipsky3, J. J. Van Netten4, N. C. Schaper5 “The 2015 IWDGF Guidance Documents on prevention and Management of Foot Problems in Diabetes: Development of an Evidence based Global Consensus” Diabetes / Metabolism Research and Reviews 2015 (13-17,19-25)
9. Waaijman R, de Haart M, Arts ML, Wever D, Verlouw AJ, Nollet F. Risk factors for plantar foot ulcer recurrence in neuropathic diabetic patients. Diabetes Care 2014 Jun;37:1697-1705.
10. Wu SC, Driver VR, Wrobel JS, Armstrong DG. Foot ulcers in the diabetic patient, prevention and treatment. Vasc Health Risk Manag2007;3:65-76
11. Lipsky BA, Berendt AR, Cornia PB. 2012 Infectious Diseases Society of America clinical practice guideline for the diagnosis and treatment of diabetic foot infections. Clin Infect Dis2012;54:e132-73
12. Lincoln NB, Radford KA, Game FL, Jeffcoate WJ. Education for secondary prevention of foot ulcers in people with diabetes: a randomised controlled trial. Diabetologia2008; 51: 1954-61.
13. Apelqvist J, Larsson J, Agardh CD. The influence of external precipitating factors and peripheral neuropathy on the development and outcome of diabetic foot ulcers. J Diabet Complications 1990 Jan-Mar;4(1):21-25.
14. Calle-Pascual AL, Durán A, Benedí A. Reduction in foot ulcer incidence: relation to compliance with a prophylactic foot care program. Diabetes Care 2001;24: 405-7.
15. Bus SA, Waaijman R, Arts M. Effect of custom-made footwear on foot ulcer recurrence in diabetes: a multicentre randomized controlled trial. Diabetes Care 2013; 36: 4109-16.
16. Cardinal M, Eisenbud DE, Armstrong DG. Serial surgical debridement: a retrospective study on clinical outcomes in chronic lower extremity wounds. Wound Repair Regen2009;17:306-311
17. O’Meara S, Al-Kurdi D, Ologun Y, Ovington LG, Martyn-St James M, Richardson R. Antibiotics and antiseptics for venous leg ulcers. Cochrane Database Syst Rev 2014:CD003557-CD003557
18. Rasmussen A, Bjerre-Christensen U, Almdal TP, Holstein P. Percutaneous flexor tenotomy for preventing and treating toe ulcers in people with diabetes mellitus. J Tissue Viability 2013 Aug;22:68-73.
19. Schepers T, Berendsen HA, Oei IH, Koning J. Functional outcome and patient satisfaction after flexor tenotomy for plantar ulcers of the toes. J Foot Ankle Surg 2010 Mar-Apr;49(2):119-122.
20. Tamir E, Vigler M, Avisar E, Finestone AS. Percutaneous tenotomy for the treatment of diabetic toe ulcers. Foot Ankle Int 2014 Jan;35(1): 38-43.
21. Tamir E, McLaren AM, Gadgil A, Daniels TR. Outpatient percutaneous flexor tenotomies for management of diabetic claw toe deformities with ulcers: a preliminary report. Can J Surg 2008 Feb;51(1):41-44.
22. Mueller MJ, Sinacore DR, Hastings MK, Strube MJ, Johnson JE. Effect of Achilles tendon lengthening on neuropathic plantar ulcers. A randomized clinical trial. J Bone Joint Surg Am 2003 Aug;85-a:1436-1445.
23. Mueller MJ, Sinacore DR, Hastings MK, Strube MJ, Johnson JE. Effect of Achilles tendon lengthening on neuropathic plantar ulcers. A randomized clinical trial. J Bone Joint Surg Am 2003 Aug;85-a:1436-1445.
24. Colen LB, Kim CJ, Grant WP, Yeh JT, Hind B. Achilles tendon lengthening: friend or foe in the diabetic foot? Plast Reconstr Surg 2012 Jan;131:37e-43e.
25. Cunha M, Faul J, Steinberg J, Attinger C. Forefoot ulcer recurrence following partial first ray amputation: the role of tendo-achilles lengthening. J Am Podiatr Med Assoc 2010 Jan-Feb;100:80-82.
26. Holstein P, Lohmann M, Bitsch M, Jorgensen B. Achilles tendon lengthening, the panacea for plantar forefoot ulceration? Diabetes Metab Res 2004 MayJun;20 Suppl 1:S37-40.
27. Armstrong DG, Lavery LA, Vazquez JR, Short B, Kimbriel HR, Nixon BP. Clinical efficacy of the first metatarsophalangeal joint arthroplasty as a curative procedure for hallux interphalangeal joint wounds in patients with diabetes. Diabetes Care 2003;26:3284-3287.
28. Lin SS, Bono CM, Lee TH. Total contact casting and Keller arthoplasty for diabetic great toe ulceration under the interphalangeal joint. Foot Ankle Int 2000 Jul;21:588-593.
29. Downs DM, Jacobs RL. Treatment of resistant ulcers on the plantar surface of the great toe in diabetics. J Bone Joint Surg Am 1982 Jul;64:930-933.
30. Vanlerberghe B, Devemy F, Duhamel A, Guerreschi P, Torabi D.
Conservative surgical treatment for diabetic foot ulcers under the metatarsal heads. A retrospective case-control study. Ann Chir Plast Esthet 2013 Aug 22.
31. Armstrong DG, Boulton AJM, Bus SA. Diabetic Foot Ulcers and Their Recurrence. N Engl J Med. 2017 Jun 15;376(24):2367-2375.