Objective: To assess the risk factors for lower limb amputations in diabetic patients presenting with foot ulcers.
Methods: The analytical cross-sectional study was conducted at the Mayo Hospital, Lahore, Pakistan, from December 1, 2019, to May 31, 2020, and comprised patients of either gender having type 1 or type 2 diabetes and foot ulcers. The wounds were assessed according to Wagner wound staging and wound sepsis was evaluated in terms of local infection of the wound, leucocytosis and osteomyelitis of the bone. The glycaemic control of these patients was assessed on presentation by measuring glycated haemoglobin levels. Data was analysed using SPSS 26.
Results: Of the 135 patients, 82(60.7%) were males and 53(39.2%) were females. Majority patients 59(43.7%) were aged 50-60 years. All 135(100%) patients underwent some type of amputation. Of all the amputations, 91(67.4%) were done in patients with poor glycaemic control on presentation, and 56(41.5%) in those with stage 4 wound. Local wound infection, increased total leukocyte count and bone showing features of osteomyelitis were significantly associated with increased risk of lower extremity amputations (p<0.05).
Conclusion: With proper glycaemic control and early presentation and treatment, majority of amputations could be avoided in diabetic patients with foot ulcers.
Keywords: Amputation, Diabetes, Osteomyelitis, Diabetic foot. (JPMA 71: 2163; 2021)
Diabetic foot ulcer (DFU) is a relatively common complication and potentially preventable complication of diabetes mellitus (DM).1 The chances for a patient having diabetes to experience DFU is about 25%. DFU is considered the major factor for lower extremity amputations in diabetics along with diabetic foot gangrene (DFG).2 It has been estimated that about 70% of lower extremity amputations are performed on diabetics and around 85% of patients initially have foot ulceration which further proceeds to lower limb amputations. In short, among diabetics, 25% develop foot ulcer during lifetime and in those patients with foot ulceration the risk of lower extremity amputation increases to 15 times compared to non-diabetics.3 Limb amputation is a major life-changing decision for the patient that results in long-term physical, social, psychological and environmental changes. Diabetic foot wound is a major health issue and it also causes socioeconomic stress on patients and their families due to long hospital stay and time for rehabilitation. Therefore, early recognition and proper management of risk factors of amputations in DFU patient may prevent major amputations and their adverse impacts.4 In the western countries, the incidence of amputation in patients with diabetic foot wounds has declined mostly due to early detection of the risk factors,5 but in the developing countries, like Pakistan, amputation is a serious problem for diabetics. Low literacy level and late presentation to healthcare facilities are the main causes that lead to amputation in such patients. Majority of the patients reach tertiary care hospitals after getting treatment from quacks for years and once their wounds gets infected irreversibly they approach tertiary care hospitals where there is no other option left than to do amputation to stop the progression of the disease and to save the life of the patient.6 To assess the risk factors for amputations, a more precise prognosis for diabetic foot (DF) patients is critical at an early age.7 Very few studies has assessed the risk factors for amputations in DF patients. In some studies, gangrene on admission, insulin-dependent diabetes, age >70 years, and peripheral arterial disease (PAD) were among the proven factors for amputation in diabetics.8 There is little data available in Pakistan about the predictors of amputations once foot ulcer has developed in diabetic patients. The current study was planned to evaluate risk factors that lead to major lower extremity amputations in DFU patients.
Patients and Methods
The analytical cross-sectional study was conducted at the Mayo Hospital, Lahore, Pakistan, from December 1, 2019, to May 31, 2020. The hospital is a tertiary care facility in the province of Punjab and serves as the teaching hospital of King Edward Medical University (KEMU), Lahore. After approval from the institutional review board of KEMU, the sample size of 135 was raised using consecutive non-probability sampling technique. All those diabetes mellitus types 1 and 2 patients were selected who presented in outpatient department (OPD) or the emergency department (ED) and were of either gender aged >13 years with wound on their lower limbs. Patients with cardiovascular disease or peripheral occlusive disease and non-diabetic patients were excluded. Patients were assessed on the basis of Wagner stage of diabetic ulcer classification,9 wound sepsis was confirmed by leucocytosis, local wound infection was assessed by sign of inflammation, like redness, hot, swelling, pain and loss of function, and osteomyelitis was assessed by X-ray findings of bone and glycaemic control on presentation. Complete blood count (CBC) was done to see the total leukocyte levels. Total leukocyte count >15 x 106cm3 was considered a sign of sepsis. Digital X-ray of the lower limb was performed in all patients to see the features of osteomyelitis in the bone, including the central area of radiolucency with a surrounding thick rim or reactive bone sclerosis, tortuous parallel lucent channels extending towards the growth plate and variable degree of periosteal new bone formation.10 Glycated haemoglobin (HbA1c) values were noted at baseline, and HbA1c >7% was taken as poor glycaemic control. Risk factors leading to amputations were assessed on the basis of above-mentioned parameters. Outcome was calculated in terms of procedure done on presentation, including ray amputation (RA), below-knee amputation (BKA) and above-knee amputation (AKA). Clinically, foot wound ulcer was assessed according to the International Working Group on Diabetic Foot Guidelines by the existence of exudate on the wound which is mostly purulent or any two of the following factors: oedema, redness and local warmth around the wound, foul smelling discharge, palpation pain, tenderness around the wound, and fever.11 All patients underwent multidisciplinary care, including complete bed rest, wound debridement, daily wound dressing, antibiotic therapy and appropriate amputation in addition to control of blood glucose. In the absence of any generally recognised criteria for classification of amputation as major or minor, for the purpose of the current study, major amputation was defined as amputation above the midtarsal bone involving the big toe, otherwise it was categorised as minor amputation. Written and informed consent from all the patients was taken on a preformed proforma after describing them the nature of the disease and nature of research work and signature were taken from all patients. Data was analysed using SPSS 26. Quantitative variables were presented as mean ± standard deviation (SD), and qualitative variables were presented as frequencies and percentages. Categorical data analysis was done using chi-square test and student's t-test. P<0.05 was considered statistically significant.
Of the 135 patients, 82(60.7%) were males and 53(39.2%) were females. Majority patients 59(43.7%) were aged 50-60 years. All 135(100%) patients underwent some type of amputation (Table-1).
Of all the amputations, 91(67.4%) were done in patients with poor glycaemic control on presentation, and 56(41.5%) in those with stage 4 wound (Table-2).
Local wound infection, increased total leukocyte count and bone showing features of osteomyelitis were significantly associated with increased risk of lower extremity amputations (p<0.05) (Table-3).
DM is considered one of the biggest contributing factors for major leg amputations as it increases the amputation rate 15-20 times. Not much literature is available in terms of evaluation of the risk factors for major amputations in diabetics. One study identified Wagner grade, ccongestive heart failure (CHF), leucocytosis, dementia and peripheral arterial occlusive disease (PAOD) as significant risk factors for amputations in diabetics.12 The current study identified and evaluated predictors of amputations in diabetics, like Wagner classification grade of DFU, wound sepsis, including local infection, leucocytosis and osteomyelitis, and basal glucose level control. It was found that good control of all parameters seemed to prevent major amputations in DFU patients. Wound state at presentation, according to Wagner grade, was the principal predictor for major amputations in all patients living with diabetes as a previous study has clearly reported the significant correlation between Wagner grading and DF amputations.13 The current study revealed that wound sepsis, including local infection along with leucocytosis and deep tissue infection in the form of osteomyelitis, were major risk factors. Osteomyelitis is the sole augmenting factor for amputation in DF patients although different types of surgical wound care are available to prevent the spread of the foot ulcer deep into the tissues.14 Wound care has also got important role in the management of diabetic ulcer on foot, which includes wound wash with normal saline and the use of latest wound management equipment. Also, many topical medicines are present that have shown promising results in the management of DF wounds depending upon patient's general health, wound state and process of tissue repair.15 According to a study, the most significant predictors for lower extremity amputation are osteomyelitis (p=0.0114), retinopathy (p=0.0001) and neuropathy (p=0.0001).16 The findings of the current study are similar. In addition, poor glycaemic control is one of the major contributors for non-healing ulcers and amputations. Good glycaemic control is important to reduce amputation risk in diabetics.17 HbA1c was measured at the time of presentation of patients and value >7% was considered poor glycaemic control. A study said HbA1c can be effectively used as lavatory parameter in DFU patients, and it can be used as a target to reduce amputation rates.18 The current study has some limitations. First, the number of DFU patients was small Which may explain the relatively higher rates of amputations observed. Moreover, the duration of study was not long enough to establish statistically significant relationship of the identified risk factors. In addition, PAOD of patients was not taken into account which is already identified as a separate risk factor of amputation in DFU patients.
Wagner grade, wound sepsis and poor glycaemic control were found to be major risk factors of amputation in DFU patients. Good attention and minimisation of these factors may prevent major amputations in DFU patients. Patient education about self-wound care, early mobilisation and proper glycaemic control were found to be the essentials for DFU management.
Conflict of Interest: None.
Source of Funding: None.
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