SLR - May 2017 - Jenna M. Lohre
Reference: Mehmet Orcun Akkurt, Ismail Demirkale & Ali Oznur (2017) Partial Calcanectomy and Ilizarov External Fixation May Reduce Amputation Need in Severe Diabetic Calcaneal Ulcers, Diabetic Foot & Ankle, 8:1, 1264699, DOI: 10.1080/2000625X.2017.1264699Scientific Literature Review
Reviewed By: Jenna M. Lohre, DPM
Residency Program: Temple University Hospital, Philadelphia, PA
Podiatric Relevance: Of the 11 million patients in the United States diagnosed with diabetes mellitus, more than 25 percent of them will develop a diabetic foot ulcer at some point in their lifetime. Of these, the majority will eventually go on to some level of amputation, further decreasing their survival rate. Diabetic foot ulcers of the rearfoot and calcaneus can often lead to amputation and are often the most difficult to treat with limb salvage. While serial debridements and antibiotic therapy have been the hallmark of diabetic foot ulcer treatment, the authors of this article evaluated the efficacy of a more recent treatment protocol, including MRI-guided surgical debridement with subsequent application of an Ilizarov external fixator.
Methods: An observational case series was conducted, including a retrospective review of prospectively collected data on 23 patients with severe diabetic foot ulcers affecting the calcaneus/heel pad. Each patient included had diabetes with varying degrees of neuropathy and vasculopathy, each had underlying osteomyelitis of the calcaneus confirmed on MRI and used a walker for ambulation support. They all received the same treatment protocol, which consisted of aggressive serial surgical debridements with excisional margins based on MRI findings, specifically findings of hypointensity on the T1-weighted image study. Subsequently, all patients underwent application of an Ilizarov external fixator with the ankle joint hinged in a plantarflexed position, which was gradually decreased 1° per day and ultimately removed seven to nine weeks postoperatively. Primary outcome measures included obvious improvement of the soft-tissue defect, eradication of the infection with obvious bone healing of previous osteomyelitis sites and clinical cure based on the Wagner classification.
Results: Of the 23 patients included in the study, a complete clinical cure, including significant wound healing in the setting of a painless and functional foot was observed in 18 patients (78 percent). Three patients (13 percent) achieved a partial recovery, which was mediated by subsequent flap operation. Lastly, two patients (nine percent) did not show improvement and were observed to have proximal and distal advancement of the ulcer site, each eventually undergoing a below-knee amputation. Additionally, the authors examined the most common pathogens affecting the data set by collecting deep wound cultures. The most common pathogens that were isolated from the wounds were S. aureus, then P. aeruginosa, and less commonly, Proteus species.
Conclusions: Severe diabetic foot infections are often the cause of repeat hospitalizations and frequently lead to morbidity and mortality. It is difficult to establish a specific protocol for diabetic foot ulcers, especially those with extensive rearfoot involvement. However, the authors have proposed an efficacious approach, MRI-guided surgical resection followed by external fixation to facilitate wound closure, which has shown to have extremely promising results. With the rate of diabetic foot ulcers on the rise, this protocol could be implemented in a variety of inpatient settings contributing to a much-needed arsenal of limb salvage techniques and aiding in the prevention of lower-extremity amputations.