Aim

Forefoot ulcers in patients with diabetic neuropathy are a result of factors that result in increased forefoot plantar pressures. Progressive hindfoot equinus from contraction of gastrocnemius-soleus-tendo-Achilles complex and progressive plantar flexed metatarsal heads secondary to claw toe deformity results callus at the metatarsal heads which break down to ulceration. The aim is to describe 2-stage treatment pathway for managing these ulcers.

Background

Diabetes is bad, common and diabetic foot ulcers (DFU) once established lead to high rates of amputation. In Nottingham our standard management for infected diabetic foot ulcers is surgical debridement, microbiological sampling, packing with gentamicin beads and targeted antibiotic therapy. Recently we have switched to packing with Stimulan, which is a purified synthetic calcium sulphate compound that can be mixed with patient appropriate antibiotics, is biodegradable and delivers better elution characteristics compared to gentamicin beads.

Introduction. Diabetic foot disease is a major public health problem with an annual NHS expenditure in excess of £1 billion. Infection increases risk of major amputation fivefold. Due to the polymicrobial nature of diabetic foot infections, it is often difficult to isolate the correct organism with conventional culture techniques, to deliver appropriate narrow spectrum antibiotics. Rapid DNA-based technology using multi-channel arrays presents a quicker alternative and has previously been used effectively in intensive care and respiratory medicine. Methods. We gained institutional and Local Ethics Committee approval for a prospective cohort study of patients with clinically infected diabetic foot wounds. They all had deep tissue samples taken in clinic processed with conventional culture and real-time PCR TaqMan array. Results. 50 samples were taken from 39 patients between October 2020 and March 2022. 84% of patient were male, 88% had type 2 diabetes. The ulcers were of variable chronicity prior to sampling (range 1–113 weeks) and mean HbA1c was 67.2mmol/mol. Ulcers were on the heel (3), midfoot (6) and forefoot (41). Minimum follow up was 3 months. 6 ulcers healed, 24 patients were admitted due to foot disease, there were 2 major amputations and 4 deaths. TaqMan array results were available a mean of 4.3 days earlier than culture results. 9 patients had negative conventional cultures and 8 were negative onarray testing. 17 patients had the same organisms detected on culture and array. 16 of these 17 had additional organisms detected by array. The most frequent organisms detected on array that were not detected by culture were Staphylococcus spp., Enterobacter, Pseudomonas and fungi. Conclusion. TaqMan array shows promise in detecting infecting organisms from diabetic foot wounds and providing earlier results than standard culture, which may enable appropriate and timely antibiotic therapy

Limited forefoot amputation in diabetic patients with osteomyelitis is frequently required. We retrospectively reviewed diabetic patients with osteomyelitis, an unhealed ulcer and blood pressure in the toe of > 45 mmHg who underwent limited amputation of the foot with primary wound closure. Between 2006 and 2012, 74 consecutive patients with a mean age of 67 years (29 to 93), and a median follow-up of 31 months, were included. All the wounds healed primarily at a median of 37 days (13 to 210; mean 48). At a median of 6 months (1.5 to 18; mean 353 days), 23 patients (31%) suffered a further ulceration. Of these, 12 patients (16% of the total) required a further amputation.

We conclude that primary wound closure following limited amputation of the foot in patients with diabetes is a safe and effective technique when associated with appropriate antibiotic treatment.

Cite this article: Bone Joint J 2013;95-B:1083–7.