Background: Diabetic foot osteomyelitis (DFO) often leads to amputations in the lower extremity. Data on the influence of the initial anatomical DFO localization on ultimate major amputation are limited. Methods: In this retrospective analysis, 583 amputation episodes in 344 patients (78 females, 266 males) were analyzed. All received a form of amputation in combination with antibiotic therapy. A multivariate logistic regression analysis with the primary outcome “major amputation” defined as an amputation above the ankle joint was performed. The association of risk factors including location of DFO, coronary artery disease, peripheral artery disease, neuropathy, nephropathy, and Charcot neuro-osteoarthropathy was analyzed. Results: Among 583 episodes, DFO was located in the forefoot in 512 (87.8%), in the midfoot in 43 (7.4%), and in the hindfoot in 28 episodes (4.8%). Overall, 53 of 63 (84.1%) major amputations were performed because of DFO in the setting of peripheral artery disease as primary indication. Overall, limb loss occurred in 6.1% (31/512) of forefoot, 20.9% (9/43) of midfoot, and 46.4% (13/28) of hindfoot DFO. Among these, 22 (41.5%) were performed as the primary treatment, whereas 31 (58.5%) followed previously failed minor amputations. Among this latter group of secondary major amputations, the DFO was localized to the forefoot in 23 of 583 (3.9%), the midfoot in 4 of 583 (0.7%) and the hindfoot in 4 of 583 (0.7%). In multivariate logistic regression analysis, initial hindfoot localization was a significant factor ( P < .05), whereas peripheral artery disease, smoking, and a midfoot DFO were not found to be risk factors. Conclusion: In our retrospective series, the frequency of limb loss in DFO increased with more proximal initial foot DFO lesions, with almost half of patients losing their limbs with a hindfoot DFO. Level of Evidence: Level IV, retrospective cohort study.

Background: Charcot arthropathy (CN) can ultimately lead to limb loss despite appropriate treatment. Initial conservative treatment is the accepted treatment in case of a plantigrade foot. The aim of this retrospective study was to investigate the mid- to long-term clinical course of CN initially being treated conservatively, and to identify risk factors for reactivation and contralateral development of CN as well as common complications in CN. Methods: A total of 184 Charcot feet in 159 patients (median age 60.0 (interquartile range (IQR) 15.5) years, 49 (30.1%) women) were retrospectively analyzed by patient chart review. Rates of limb salvage, reactivation, contralateral development and common complications were recorded. Statistical analysis was performed to identify possible risk factors for limb loss, CN reactivation, contralateral CN development, and ulcer development. Results: Major amputation-free survival could be achieved in 92.9% feet after a median follow-up of 5.2 (IQR 4.25, range 2.2–11.25) years. CN recurrence occurred in 13.6%. 32.1% had bilateral CN involvement. Ulcers were present in 72.3%. 88.1% patients were ambulating in orthopaedic footwear without any further aids. Presence of Diabetes mellitus was associated with reactivation of CN, major amputation and ulcer recurrence. Smoking was associated with ulcer development and necessity of amputations. Conclusions: With consistent conservative treatment of CN with orthopaedic footwear or orthoses, limb preservation can be achieved in 92.9% after a median follow-up of 5.2 years. Patients with diabetic CN are at an increased risk of developing complications and CN reactivation. To prevent ulcers and amputations, every effort should be made to make patients stop smoking. Level of Evidence: III, long-term retrospective cohort study

We investigated the impact of the total length of systemic antibiotic therapy (ABT) and its initial intravenous (IV) part on clinical failure (CF) and microbiological failure (MF) in diabetic foot infections (DFIs). In this single-center, retrospective, unmatched case-control study, we included DFI episodes treated with a combined surgical-antibiotic approach. We included 721 DFI episodes, 537 with osteomyelitis (DFO). CF occurred in 191 (26.5%) and MF in 42 (5.8%) episodes. Multivariate Cox regression analysis showed that a short ABT of 8-21 days (hazard ratio [HR] 0.4; 95% CI 0.2-0.7) was inversely associated with CF. This was also applicable for IV ABT with relatively short durations of 2-7 days (HR 0.5; 95% CI 0.3-0.8) or 8-14 days (HR 0.6; 95% CI 0.4-0.9). We failed to detect a minimal threshold of total or IV ABT predictive for CF or MF. Compared with total ABT of more than 84 days and IV therapy of more than 14 days, shorter total and IV ABT yielded no enhanced risk of CF or MF. Considering the "bias by indication" that is inherent to retrospective DFI studies, the best study design concerning the duration of ABT would be a stratified, prospective randomized trial, which is currently under way in our medical center.

Background: There is uncertainty regarding the optimal surgical intervention for diabetic foot osteomyelitis (DFO). Conservative surgery—amputation-free resection of infected bone and soft tissues—is gaining traction as an alternative to minor amputation. Our primary objective was to explore the comparative effectiveness of conservative surgery and minor amputations in clinical failure risk 1 year after index intervention. We also aimed to explore microbiological recurrence at 1 year, and revision surgery risk over a 10-year study period. Methods: Retrospective, single-center chart review of DFO patients undergoing either conservative surgery or minor amputation. We used multivariable Cox regression and Kaplan-Meier estimates to explore the effect of surgical intervention on clinical failure (recurrent diabetic foot infection at surgical site within 1 year after index operation), microbiological recurrence at 1 year, and revision surgery risk over a 10-year follow-up period. Results: 651 patients were included (conservative surgery, n = 121; minor amputation, n = 530). Clinical failure occurred in 34 (28%) patients in the conservative surgery group, and in 111 (21%) of the minor amputation group at 1 year ( P = .09). After controlling for potential confounders, we found no association between conservative surgery and clinical failure at 1 year (adjusted hazard ratio [HR] 1.3, 95% CI 0.8-2.1). We found no between-group differences in microbiological recurrence at 1 year (conservative surgery: 8 [6.6%]; minor amputation: 33 [6.2%]; P = .25; adjusted HR 1.1, 95% CI 0.5-2.6). Over the 10-year period, the conservative group underwent significantly more revision surgeries (conservative surgery: 85 [70.2%]; minor amputation: 252 [47.5%]; P < .01; adjusted HR 1.3, 95% CI 0.9-1.8). Conclusion: We found that with comorbidity-based patient selection, conservative surgery in the treatment of DFO was associated with the same rates of clinical failure and microbiological recurrence at 1 year, but with significantly more revision surgeries during follow-up, compared with minor amputations. Level of Evidence: Level III, retrospective comparative effectiveness study.

Therapy for diabetic foot osteomyelitis (DFO) with Charcot neuroosteoarthropathy is challenging. In patients with diabetic Charcot osteomyelitis (DCO), both the anatomic deformity and infection must be addressed. This study assessed the outcomes of DCO therapy and variables associated with treatment failure and compared them with outcomes of DFO cases. A single-center, retrospective, case-control study was performed to compare 93 DCO episodes with 530 DFO episodes, using Kaplan-Meier survival curves and multivariate Cox regression analyses. Clinical failure occurred in 21.5% of DCO compared with 22.3% in DFO episodes (p=0.89) and was associated with peripheral arterial disease (PAD) stages 3 or 4 (HR 6.1; CI 2.0-18.1) and chronic treatment with immunosuppressives (HR 7.4; CI 2.0-27.1). Major amputations were significantly more frequent in DCO (28% versus 13.6%; p<0.01) and associated with PAD stages 3 and 4 (HR 8.0; CI 2.2-29.4), smoking (HR 5.4; CI 1.2-24.6), alcohol abuse (HR 3.5; CI 1.1-10.6), and renal dialysis (HR 4.9; CI 1.3-18.9). Clinical treatment failures did not differ between DCO and DFO. However, patients with DCO underwent major amputation twice as often as those with DFO. Unlike widespread belief, treatment failure in DCO patients may, similar to DFO, be associated with a striking epidemiological link to severe PAD.

Background: The contralateral foot in Charcot arthropathy or neuroarthropathy (CN) is subject to increased plantar pressure. To date, the clinical consequences of this pressure elevation are yet to be determined. The aim of this study was to evaluate ulcer and amputation rates of the contralateral foot in CN. Methods: We abstracted the medical records of 130 consecutive subjects with unilateral CN. Rates of contralateral CN development and recurrence, contralateral ulcer development, and contralateral amputations were recorded. Statistical analysis was performed to identify possible risk factors for contralateral CN and ulcer development, and contralateral amputation. Mean follow-up was 6.2 (SD 4) years. Results: After a mean of 2.5 years, 19.2% patients developed contralateral CN. Female gender was associated with contralateral CN development (odds ratio 3.13, 95% confidence interval 1.27, 7.7). Overall, 46.2% patients developed a contralateral ulcer. Among the patients who developed contralateral CN, 60% developed an ulcer. Sanders type 2 at the index foot (midfoot CN) was significantly associated with contralateral ulcer development. Ulcer-free survival (UFS) differed significantly between patients with diabetes type 1 (median UFS 5131 days) and patients with diabetes type 2 (median UFS 2158 days). A total of 25 amputations had to be performed in 22 (16.9%) patients. Three of those 22 patients (2.3%) needed major amputation. Conclusion: Almost 20% of patients developed contralateral CN. Nearly half of people with CN developed a contralateral foot ulceration. Patients with type 2 diabetes had significantly shorter UFS than patients with diabetes type 1. Every sixth patient needed an amputation, with the majority being minor amputations. The contralateral foot should be monitored closely and included in the treatment in patients with CN. Level of Evidence: Level IV, retrospective study.