The Association between Foot Surgery Type and Subsequent Healing in Veterans with Moderate-to-Severe Diabetic Foot Infections

Background Diabetic foot infections are a common precursor to lower extremity amputations. The treatment of diabetic foot infections involves both medical and surgical management, of which limb-sparing surgeries are increasingly preferred over amputations at or above the ankle to preserve mobility and quality of life. The outcomes following these limb-sparing surgeries are not well-described. Methods This was a single-center, retrospective cohort study of 90 Veterans with moderate-to-severe diabetic foot infections between 2017 and 2019 from the VA Maryland Health Care System. The exposure was foot surgery with bone resection (i.e., toe amputation, metatarsal resection, transmetatarsal amputation) versus debridement alone. The outcome was healing within 1 year. We used log-binomial regression to assess the association between foot surgery type and healing, stratify by infection location, and evaluate potential confounding variables. Results The cumulative incidence of healing after foot surgery with bone resection was greater than that following debridement (risk ratio 1.80, 95% confidence interval [1.17, 2.77]). This association was modified by infection location and greater for toe infections (4.52 [1.30, 15.7]) than other foot infections (1.19 [0.69, 2.02]). We found no evidence of confounding by comorbidities or infection severity. Conclusions For patients with toe infections, foot surgery with bone resection was associated with better healing than debridement alone. The multiple specialties caring for patients with diabetic foot infections need a stronger common knowledge base—from studies like this and future studies—to better counsel patients about their treatment and prognosis.

Free Tissue Transfer after Open Transmetatarsal Amputation in Diabetic Patients

Background Transmetatarsal amputation (TMA) preserves functional gait while avoiding the need for prosthesis. However, when primary closure is not possible after amputation, higher level amputation is recommended. We hypothesize that reconstruction of the amputation stump using free tissue transfer when closure is not possible can achieve similar benefits as primarily closed TMAs. Methods Twenty-eight TMAs with free flap reconstruction were retrospectively reviewed in 27 diabetic patients with a median age of 61.5 years from 2004 to 2018. The primary outcome was limb salvage rate, with additional evaluation of flap survival, ambulatory status, time until ambulation, and further amputation rate. In addition, subgroup analysis was performed based on the microanastomosis type. Results Flap survival was 93% (26 of 28 flaps) and limb salvage rate of 93% (25 of 27 limbs) was achieved. One patient underwent a second free flap reconstruction. In the two failed cases, higher level amputation was required. Thirteen flaps had partial loss or other complications which were salvaged with secondary intension or skin grafts. Median time until ambulation was 14 days following reconstruction (range: 9–20 days). Patients were followed-up for a median of 344 days (range: 142–594 days). Also, 88% of patients reported good ambulatory function, with a median ambulation score of 4 out of 5 at follow-up. There was no significant difference between the subgroups based on the microanastomosis type. Conclusion TMA with free flap reconstruction is an effective method for diabetic limb salvage, yielding good functional outcomes and healing results.

Custom Dynamic Orthoses and Physical Therapist Intervention for Bilateral Midfoot Amputation: A Case Report

Objective Partial foot amputation (PFA) is often associated with decreased mobility and function. Recent advances in custom carbon-fiber dynamic ankle-foot orthoses (CDO) have improved gait, pain, and function following musculoskeletal trauma and may benefit individuals with PFA. However, limited information is available related to CDO use outside the military. The purpose of this case report is to describe the course of care and outcomes of a civilian provided CDOs after bilateral transmetatarsal amputation. Methods (Case Description) A 72-year-old man had a blood-borne bacterial infection (septicemia) of unknown origin at 68 years of age, developed limb threatening necrosis of the hands and feet, and received bilateral transmetatarsal amputations with skin grafting. The patient initially used foam toe fillers and cushioned shoes but was functionally limited and experienced recurrent ulceration. He was fit with bilateral CDOs 39 months after amputation and completed device-specific training with a physical therapist. Results After 1 week with the CDOs, ankle ROM during gait was reduced, but greater than 40% increases were observed in bilateral ankle plantar-flexor moments and ankle plantar-flexion push-off power compared with the toe fillers. With additional therapist-directed training focused on gait and activity performance, ankle plantar-flexor moments and plantar-flexion push-off power further increased when compared with results after 1 week of CDO use. The patient reported marked improvement in quality of life with the CDOs due to improved walking ability on level and uneven terrain, marked improvement in confidence, and reduced pain. Conclusion This case reflects the lessons learned and outcomes of a civilian using bilateral CDOs after bilateral transmetatarsal amputation and with poor skin quality. The results from this case study suggest that carbon fiber CDOs and focused training by a physical therapist can result in improved gait biomechanics, mobility and quality of life.

Mönckeberg’s Disease of the Lower Limb

Vascular calcification represents a group of several pathological states of differing aetiologies. Mönckeberg medial sclerosis is considered to be more widespread in the lower abdominal region and lower limbs. We present a 59-years-old male patient presented right foot gangrene. At physical exploration, femoral and popliteal pulses were presented and the ankle-brachial pressure index was 0.45, and the toe-brachial index was 0.33. The patient underwent distal angioplasty of anterior and posterior tibial arteries and due to inaccurate evolution a transmetatarsal amputation was required. Mönckeberg’s medial sclerosis is diagnosed with an ABI>1.1, however, questions have been raised about the validity and the role of ABI in diagnosis of Mönckeberg’s medial sclerosis. Colour-doppler vascular ultrasound allow a non-invasive technique widely available to detect vascular calcification and to differentiation between Mönckeberg’s medial sclerosis and the atherosclerosis-related lesions.

Mortality and Conversion Rate to Below Knee or Above Knee Amputation Following Transmetatarsal Amputation

Category: Midfoot/Forefoot; Diabetes; Other Introduction/Purpose: Non-traumatic lower extremity amputations (LEA), especially those performed in dysvascular and diabetic patients, are known to have poor long-term prognosis. Perioperative mortality has been reported at between 4 and 10%, and the 1 and 5 year mortality rates range between 22-33% and 39-69%, respectively. While poor outcomes in these patients have been described, there is no consensus as to the predictors of mortality. The purpose of the study is to determine the percentage of patients who had a complication following transmetatarsal amputation (TMA) and identify associated risk factors for complications and mortality. Methods: We queried our institution’s administrative database to identify 247 TMA procedures performed in 229 patients between January, 2002 and December, 2016. Electronic health records were reviewed to document complications defined as reoperation, amputation and mortality. Mortality was also verified using the National Death Index. Additionally, we recorded risk factors including diabetes, A1c level, end stage renal disease (ESRD), cardiovascular disease (CVD), peripheral vascular disease (PVD), history of revascularization, contralateral amputation, and neuropathy. The majority of the study patients were males (157, 69%) and the average age was 57 years (range 24-91). The median BMI was 28 (range 16-58) and 29% of the study patients were obese with a BMI ≥ 30. Fishers Exact tests were used to compare categorical variables. Kruskal-Wallis and Independent T-tests were used to compare numeric data. All data were analyzed using SAS/STAT software version 9.4 (Carey, NC) and a 0.05 level of significance was defined apriori. Results: The conversion rate to below (BKA) or above knee amputation (AKA) was 26% (64 of 247). Males (p=.0274), diabetics (p=.0139), patients in ESRD (p=.019), and patients with a history of CVD (p=.0247) or perioperative revascularization (p=.022) were more likely to undergo further amputation following an index TMA. BMI was significantly higher in patients requiring BKA/AKA (p=.0305). There were no significant differences in age (p=.2723) or A1c levels (p=.4219). The overall mortality rate was 35% (84 of 229). Diabetes (p=.0272), ESRD (p=.0031), history of CVD (p<.0001) or PVD (p=.0179) were all significantly associated with mortality. Patients who died were significantly older (p=.0006) and had significantly higher A1c levels (p=.0373). BMI was not significantly associated with mortality. Twenty-two patients who had 23 further amputations subsequently died. Conclusion: In our series of patients undergoing TMA, 26% underwent further amputation and 35% of patients died. Conversion rate to BKA or AKA occurred at a high rate regardless of preoperative revascularization or the use of tendo-achilles or gastrocnemius lengthening procedures. Male sex, diabetes, ESRD, history of CVD or revascularization are significant risk factors for further amputation. ESRD, diabetes, history of CVD or PVD, older age and higher A1c levels are significant risk factors for mortality. These data provide useful insight into risk factors to be emphasized when counseling patients and their families to establish realistic postoperative expectations.