Javier La Fontaine

The Role of Revascularization in Transmetatarsal Amputations

Data from 37 patients who underwent a transmetatarsal amputation from January 1993 to April 1996 were reviewed. The mean age and diabetes duration of the subjects were 54.9 (+/- 13.2) years and 16.6 (+/- 8.9) years, respectively. The follow-up period averaged 42.1 (+/- 11.2) months. At the time of follow-up, 29 (78.4%) of the 37 patients still had foot salvage, 8 (21.6%) had progressed to below-the-knee amputation, and 15 (40.5%) had undergone lower-extremity revascularization. Twelve (80%) of the 15 revascularized patients preserved their transmetatarsal amputation level at a follow-up of 36.4 months. The authors concluded that at a maximum of 3 years follow-up after initial amputation, transmetatarsal amputation was a successful amputation level.

Randomised clinical trial to compare total contact casts, healing sandals and a shear-reducing removable boot to heal diabetic foot ulcers

The objective of this study was to evaluate the efficacy of three off‐loading techniques to heal diabetic foot wounds: total contact casts (TCCs), healing sandals (HSs) and a removable boot with a shear‐reducing foot bed (SRB). This was a 12‐week, single‐blinded randomised clinical trial with three parallel treatment groups of adults with diabetes and a foot ulcer (n = 73). Ulcer healing was defined as full reepithelialisation with no drainage. Diabetic patients with grade UT1A or UT2A forefoot ulcers on the sole of the foot were enrolled. Patients with malignancy, immune‐compromising diseases, severe peripheral vascular disease (ankle‐brachial index < 0·60 or transcutaneous oxygen < 25 mm/Hg), alcohol or substance abuse within 6 months, untreated osteomyelitis or Charcot arthropathy with residual deformity that would not fit the HS or boot were excluded. In the intent‐to‐treat analysis, significantly higher proportion of patients were healed in the TCC group (69·6%) compared to those treated with the SRB (22·2%, P < 0·05). There was no difference in the rate of healed ulcers in the HS (44·5%) and TCC groups. Ulcers in the TCC group healed faster than those in the HS group (5·4 ± 2·9 versus 8·9 ± 3·5 weeks, P < 0·02). However, there was no difference in the time to healing in the TCC and SRB groups (6·7 ± 4·3 weeks, P = 0·28). Patients who used HS were significantly more active (4022 ± 4652 steps per day, P < 0·05) than those treated with TCCs (1447 ± 1310) or SRB (1404 ± 1234). It is concluded that patients treated with TCCs had the highest proportion of healed wounds and fastest healing time. The novel shear‐reducing walker had the lowest healing and highest rate of attrition during the study.

Amputations and foot‐related hospitalisations disproportionately affect dialysis patients

Patients with diabetes have increased risk for foot ulcers, amputations and hospitalisations. We evaluated a closed cohort of patients with diabetes and established risk factors in two high risk groups: (i) dialysis patients and (ii) patients with previous foot ulceration. We used claims data for diabetes (ICD‐9 250.X), ulceration (ICD‐9 707·10, 707·14 and 707·15) and dialysis (CPT 90935–90937) from the Scott and White Health Plan to identify 150 consecutive patients with diabetes on dialysis (dialysis group) and 150 patients with a history of foot ulceration (ulcer history group). We verified these diagnoses by manually reviewing corresponding electronic medical records. Each patient was provided 30 months follow‐up period. The incidence of foot ulcers was the same in dialysis patients and patients with an ulcer history (210 per 1000 person‐years). The amputation incidence rate was higher in dialysis patients (58·0 versus 13·3, P < 0·001). Hospital admission was common in both study groups. The incidence of hospitalisation was higher in the ulcer history group (477·3 versus 381·3, P < 0·001); however, there were more foot‐related hospital admissions in the dialysis group (32·9% versus 14·0%, P < 0·001) during the 30‐month evaluation period. The incidence of ulcers, amputations and all‐cause hospitalisations is high in persons with diabetes and a history of foot ulceration or on dialysis treatment; however, those on dialysis treatment have disproportionately higher rates of foot‐related hospitalisations. Intervention strategies to reduce the burden of diabetic foot disease must target dialysis patients as a high‐risk group.

Risk factors for methicillin-resistant Staphylococcus aureus in diabetic foot infections

Objective The purpose of this study was to evaluate risk factors for methicillin-resistant Staphylococcus aureus (MRSA) in patients hospitalized for diabetic foot infections. Methods We reviewed hospital admissions for foot infections in patients with diabetes which had nasal swabs, and anaerobic and aerobic tissue cultures at the time of admission. Data collected included patient characteristics and medical history to determine risk factors for developing an MRSA infection in the foot. Results The prevalence of MRSA in these infections was 29.8%. Risk factors for MRSA diabetic foot infections were history of MRSA foot infection, MRSA nasal colonization, and multidrug-resistant organisms (p<0.05). Positive predictive value (PPV) and negative predictive value (NPV) of nasal colonization with MRSA to identify MRSA diabetic foot infections were 66.7% and 80.0% (sensitivity 41%, specificity 90%). Admission from a nursing home was not a significant risk factor. Conclusion Positive nasal swabs are not predictive of the infecting agent; however, a negative nasal swab rules out MRSA as the infecting agent in foot wounds with 90% accuracy.

Preventing the First or Recurrent Ulcers

Prevention is overlooked and underused, even in very high-risk patients. Prevention is best achieved within a multispecialty group of providers that have a common objective. Ideally, the team approach should include educators; physical therapists; nurses; internist; pedorthists; and vascular, orthopedic, and podiatric surgeons. The basic elements involve education, foot examination, risk classification, therapeutic shoes and insoles, and regular foot care. High-risk patients need additional assessment for vascular disease and intensive disease management, and corrective vascular and foot surgery when necessary. Basic interventions can reduce the incidence of foot ulcers by more than 50%.

Erythrocyte sedimentation rate and C-reactive protein to monitor treatment outcomes in diabetic foot osteomyelitis

This study sought to evaluate the effectiveness of the inflammatory markers, erythrocyte sedimentation rate (ESR) and C‐reactive protein (CRP), in monitoring treatment of osteomyelitis in the diabetic foot. We screened 150 charts of patients admitted to our hospital with diabetic foot osteomyelitis (DFO), confirmed by positive results of bone culture and/or histopathology. We included patients who had an initial ESR/CRP within 72 hours of admission and two reported follow‐up values. We dichotomised patients based on the outcomes wound healing, re‐infection, recurrent ulceration, re‐hospitalisation, additional surgery, re‐amputation and death, all within 12 months, and analysed the trajectories of the markers over time. Our primary outcome, DFO remission, was defined as wound healing within 12 months of follow‐up without re‐infection. We included 122 subjects; 65 patients (53·3%) had a combination of positive culture and histopathology. Factors associated with DFO remission (n = 46) were a lower white blood count (WBC) at admission (P = 0·006) and a higher glomerular filtration rate (GFR, P = 0·049). Factors associated with healing were a lower WBC (P = 0·004), a higher GFR (P = 0·01), longer wound duration before admission (P = 0·01), location of the ulcer on the great toe (P = 0·01) and higher glycated haemoglobin (P = 0·03). Logistic regression analysis demonstrated no associations between DFO remission and other variables collected. Trajectories of the inflammatory markers showed an association between stagnating values of ESR and CRP and poor clinical outcomes. In this study population, the trajectories of both ESR and CRP during 12 months follow‐up suggest a predictive role of both inflammatory markers when monitoring treatment of DFO.

Hybrid imaging with 99mTc-WBC SPECT/CT to monitor the effect of therapy in diabetic foot osteomyelitis

This study sought to assess the utility of monitoring response to treatment of diabetic foot osteomyelitis (DFO) with Tc‐99m WBC‐labelled single photon emission computed tomography (SPECT/CT) imaging. This is a retrospective cohort study of 20 patients with DFO with sequential Tc‐99m WBC‐labelled SPECT/CT imaging. Radiologic findings of osteomyelitis were evaluated and imaging results were correlated with clinical outcomes subtracted from chart review. Successful treatment of osteomyelitis was defined by wound healing and/or lack of re‐admission for bone infection of the same site within 1 year. The sensitivity, specificity, positive predictive value and negative predictive value of SPECT/CT to determine osteomyelitis treatment remission were 90%, 56%, 69% and 83%, respectively. Tc‐99m WBC‐labelled SPECT/CT imaging may be useful to help determine treatment outcomes for DFO.

The value of inflammatory markers to diagnose and monitor diabetic foot osteomyelitis

In this study, we assessed the effectiveness of inflammatory markers to diagnose and monitor the treatment of osteomyelitis in the diabetic foot. We evaluated 35 consecutive patients admitted to our hospital with infected foot ulcers. Patients were divided in two groups based on the results of bone culture and histopathology: osteomyelitis and no osteomyelitis. The erythrocyte sedimentation rate (ESR), C‐reactive protein (CRP), procalcitonin (PCT), interleukin‐6 (IL‐6), interleukin‐8 (IL‐8), tumor necrosis factor alpha (TNFα), monocyte chemotactic protein‐1 (MCP‐1) and macrophage inflammatory protein‐1 alpha (MIP1α) were measured at baseline after 3 and 6 weeks of standard therapy. PCT levels in the osteomyelitis group were significantly higher at baseline than in the group with no osteomyelitis (P = 0·049). There were no significant differences between the two groups in the levels of the other markers. CRP, ESR, PCT and IL‐6 levels significantly declined in the group with osteomyelitis after starting therapy, while MCP‐1 increased (P = 0·002). TNFα and MIP1α levels were below range in 80 out of 97 samples and therefore not reported. Our results suggest that PCT might be useful to distinguish osteomyelitis in infected foot ulcers. CRP, ESR, PCT and IL‐6 are valuable when monitoring the effect of therapy.

Current concepts of Charcot foot in diabetic patients.

The Charcot foot is an uncommon complication of neuropathy in diabetes. It is a disabling and devastating condition. The etiology of the Charcot foot is unknown, but it is characterized by acute inflammation with collapse of the foot and/or the ankle. Although the cause of this potentially debilitating condition is not known, it is generally accepted that the components of neuropathy that lead to foot complications must exist. When it is not detected early, a severe deformity will result in a secondary ulceration, infection, and amputation. Immobilization in the early stages is the key for success, but severe deformity may still develop. When severe deformity is present, bracing may be attempted but often patients will need surgical intervention. Good success has been shown with internal and external fixation. In patients with concomitant osteomyelitis, severe deformity, and/or soft tissue infection, a high amputation may be the best treatment of choice.

Comparison of Transtibial Amputations in Diabetic Patients With and Without End-Stage Renal Disease.

Background: The primary purpose of this retrospective study was to report on a consecutive series of 102 patients with diabetes mellitus (DM) who underwent transtibial amputation (TTA) for chronic infections and nonreconstructable lower extremity deformities. A secondary aim was to compare the outcomes of TTA patients with end-stage renal disease on dialysis (ESRD) to patients without ESRD, and to identify risk factors for mortality after TTA. Methods: This cohort involved a consecutive series of patients who were treated by a single surgeon. The TTA patients were divided into 2 groups for analysis. The study group included those patients with ESRD who underwent TTA, and the control group included those patients who did not have ESRD. Results: At the time of final follow-up, 64 of 102 patients were ambulatory with a prosthesis. There was a significant improvement in ambulatory status after amputation (preoperatively 45.1%, postoperatively 62.7%, P = .02). Wound healing complications (infection and/or dehiscence) occurred in 31 of 102 patients and led to a transfemoral amputation in 4 patients. After TTA patients with ESRD were significantly more likely to die (52.4% vs. 23.5%, p <0.05) and significantly less like to ambulate (42.9% vs. 67.9%, p <0.05) than patients without ESRD. Contralateral foot problems after the TTA occurred in 33 of 97 patients and resulted in 10 patients undergoing a contralateral transtibial amputation. Excluding patients with bilateral amputations (5 prior to and 10 after the index amputation), 64 of 87 patients with successful unilateral transtibial amputations were able to ambulate with a prosthesis. Thirty of 102 patients (29.4%) died during the follow-up period, and 6 of these deaths occurred during the perioperative period (within 30 days of surgery). There were no significant differences between the 2 groups with regard to the use of staged TTA, need for transfemoral amputation, or wound healing problems at the amputation site. Patients who were unable to walk postoperatively had a calculated 5-year survival rate of 30.1%, whereas those who were ambulatory had a 5-year survival rate of 68.8%. Cox proportional hazards model demonstrated a 62% reduced risk of mortality in patients who were able to ambulate after LEA compared with those patients who were not able to ambulate. Conclusion: TTA in patients with diabetes was associated with substantial morbidity and mortality. Risk factors that were significantly associated with an increased rate of mortality were the presence of ESRD, age ≥56 years, and inability to ambulate postoperatively. Level of Evidence: Level III, retrospective case controlled study.