A Novel Approach to the Management of the Diabetic Foot: Metatarsal Excision in the Treatment of Osteomyelitis

The internal pedal amputation as a salvage procedure in diabetic and ischemic foot infection. A meta-analysis

BACKGROUND

Osteomyelitis of the diabetic foot is a very challenging condition and amputation is often indicated. In some cases where the infection is localized and the surrounding soft tissue is mildly involved, an internal pedal amputation (IPA) based on resection and limited excision of the infected bone have been suggested as a viable option. This systematic review aims to look for the effectiveness of this technique in treating selected cases of diabetic foot osteomyelitis.

METHODS

A systematic literature search was conducted using multiple electronic databases from inception. Eight studies met the inclusion criteria; one retrospective comparative study, six retrospective observational studies and one prospective observational study.

RESULTS

Based on a pooled sample of 545 patients followed over a mean period of 27.7 ± 15.2 months, the weighted results were as follows: (a) healing rate was 87.7% (95% CI = 0.757-0.959), (b) time for healing was 7.1 ± 2.9 weeks, (c) wound infection rate was 5.6% (95% CI = 0.030-0.089), (d) wound dehiscence rate was 8% (95% CI = 0.010-0.204), (e) ulcer recurrence rate was of 10% (95% CI = 0.037-0.188), and (f) amputation rate was 2.8% (95% CI = 0.001-0.085) whilst all were minor amputations.

CONCLUSION

The findings support the selection of toe/ray sparing surgery via IPA as a viable surgical option for selected cases of focal osteomyelitis secondary to diabetic foot infection. The results would indicate that when the ulcer size could be adequately reduced, removing the infected bone while preserving the soft tissue envelope could yield high chance of success with few serious complications.

Diagnostic Accuracy of Bone Culture Versus Biopsy in Diabetic Foot Osteomyelitis

OBJECTIVE

To compare the diagnostic accuracy of bone culture (microbiology) and biopsy (histology) in patients with acute or chronic diabetic foot osteomyelitis (DFO).

METHODS

This cross-sectional study involved patients for whom providers had a clinical suspicion of DFO. Two bone samples were taken: one for microbiologic testing and another for histologic testing. The sensitivity, specificity, positive predictive value, negative predictive value, and likelihood ratio were calculated for bone culture results in relation to the probability of DFO diagnosis.

RESULTS

Fifty-two patients were included; 69% had positive bone culture results, and 90.4% had positive histology results (P = .013), and of those 90.4%, 25.5% had acute and 74.5% had chronic DFO. The sensitivity of the microbiologic bone culture result was 0.70, the specificity was 0.40, the positive predictive value was 0.92, and the negative predictive value was 0.13.

CONCLUSIONS

Histology provides more accurate diagnosis of DFO than microbiology, especially for patients with chronic DFO. These patients could be underdiagnosed because of false-negative results provided by bone culture. Providers should perform both tests to confirm the presence of DFO.

Surgery Versus Nonsurgical Methods in Treating Neuropathic Plantar Forefoot Ulcers: A Meta-Analysis of Comparative Studies

The treatment of diabetic foot ulcers (DFUs) is usually based on local debridement, topical agents, and nonsurgical off-loading. When compared with nonsurgical methods, a number of articles reported better results with surgery. The aim of this meta-analysis was to collate quantitative evidence on the outcomes of surgery versus nonsurgical treatment (NST) of DFUs. Databases were searched from inception to September 2019. PRISMA guidelines were followed, and the Joanna Briggs Institute critical appraisal tools were used to appraise studies' quality. Nine studies were included totalizing 436 ulcers (216 treated with surgery and 220 DFUs with NST). The primary outcome was the healing rate. The secondary outcomes were time to heal, recurrence rate, transfer rate, infection rate, and amputation/revision surgery rate. The risk differences (RDs) between the healing rates following surgery and NST for infected and noninfected ulcers were 17% (95% confidence interval [CI] = 0.012-0.328, P = .03) and 19.2% (95% CI = 0.050-0.334, P = .008), respectively, in favor of surgery. The amputation/revision surgery rate was significantly better following surgery for both types of ulcers. Noninfected ulcers demonstrated significantly lesser time to heal, recurrence, and infection rates following surgery. This meta-analysis demonstrated that surgery was superior to NST in treating infected and noninfected neuropathic plantar wounds.

Conservative Surgery of Diabetic Forefoot Osteomyelitis: How Can I Operate on This Patient Without Amputation?

Surgery is necessary in many cases of diabetic foot osteomyelitis. The decision to undertake surgery should be based on the clinical presentation of diabetic foot osteomyelitis. Surgery is required when the bone is protruding through the ulcer, there is extensive bone destruction seen on x-ray or progressive bone damage on sequential x-ray while undergoing antibiotic treatment, the soft tissue envelope is destroyed, and there is gangrene or spreading soft tissue infection. Several issues should be taken into account when considering surgery for treating diabetic foot osteomyelitis. It is necessary to have a surgeon available with diabetic foot expertise. Regarding location of diabetic foot osteomyelitis, it is important to consider whether isolated bone or a joint is involved. In cases in which osteomyelitis is associated with a bone deformity, surgery should be able to correct this. The surgeon should always reflect about whether extensive/radical surgery could destabilize the foot. The forefoot is the most frequent location of diabetic foot osteomyelitis and is associated with better prognosis than midfoot and hindfoot osteomyelitis. Many surgical procedures can be performed in patients with diabetes and forefoot ulcers complicated by osteomyelitis while avoiding amputations. Performing conservative surgeries without amputations of any part of the foot is not always feasible in cases in which the infection has destroyed the soft tissue envelope. Attempting conservative surgery in such cases risks infected tissues remaining in the wound bed leading to failure. The election of different surgical options depends on the expertise of the surgeons selected for the multidisciplinary teams. It is the aim of this article to provide a sample of surgical techniques in order to remove the bone infection from the forefoot while avoiding amputations.