Breaking the Cycle of Recurrent Diabetic Foot Ulceration: A Novel and Sustainable Offloading Modality to Treat Diabetic Foot Ulceration and Prevent Recurrence

The article incorrectly referenced an intermittent compression bladder being located both at the level of the calf and the arch of the foot. An intermittent compression bladder is only located at the arch of the foot. There is no intermittent compression bladder located at the level of the ankle in this novel offloading device. 

Diabetic foot ulceration (DFU) affects 12% to 25% of those with diabetes and is the leading cause of diabetes-related hospitalization.^1-4 Pressure is a major contributor to delayed healing in more than 90% of these ulcerations.^5-8 Offloading in conjunction with optimal medical management and advanced local wound care is critical to resolution of DFU.^5-10 Depending on the modality used, patient compliance can affect success and time to healing.⁶ The importance of continued foot protection following DFU resolution is paramount in preventing recurrence.³

The total contact cast (TCC) is considered the reference standard in offloading.^11-14 The concept was first introduced in the 1960s as a modality for treatment of leprosy-related neuropathic ulceration.¹⁵ Since then, treatment has shifted to use of such casting in the management of DFUs, with several randomized controlled trials, systematic reviews, and meta-analyses showing statistically significant reductions in healing times and increased healing rates compared with use of a therapeutic/postoperative shoe and removable cast walking boot.^6,16-21 Even so, these latter modalities remain the most commonly used for offloading DFUs. Barriers to TCC use include the time required for application and removal, the contraindication to its use in patients with ischemia or infected ulcerations, and patient intolerance.^{11-14,19,20,22-25} What all these offloading modalities have in common is that their use ends with wound resolution, after which patients are transitioned back to “normal” or therapeutic footwear. Compliance with appropriate lifelong use is debatable given DFU recurrence rates of 40%, 60%, and 65% within 1 year, 3 years, and 5 years, respectively, following resolution.³ Presented here is the case of a patient with a 2-year history of a recurrent DFU. This cycle of recurrence ended with implementation of a novel offloading device that took into account patient comfort and satisfaction in addition to offloading and perfusion enhancement. This device can be used for treatment and recurrence prevention.

A 75-year-old male with type 2 diabetes presented to the author’s hospital with a 2-year history of recurrent DFU of the right plantar fourth metatarsal head (Figure 1). The patient had previously undergone amputation of the right fourth digit secondary to DFU and acute osteomyelitis. The second and third digits dorsally dislocated over time, resulting in increased pressure on the right fourth plantar metatarsal head. Despite routine foot care and self-reported compliance with therapeutic footwear use, the patient had undergone a 2-year cycle of DFU resolution and recurrence. Treatment used in each instance for DFU resolution was surgical debridement, targeted antibiotic treatment when indicated, and use of a removable walking boot. A removable walking boot was used rather than a TCC because of the patient’s need to drive for his job. The patient would be transitioned back to normal orthopedic footwear use and instructed to return for routine foot care after each instance of DFU resolution. 

In an attempt to curtail this repetitive 2-year cycle of recurrent ulceration, the decision was made to modify the typical treatment course by using a novel offloading modality (PulseFlow DF; Pulse Flow Technologies, Inc) rather than a removable walking boot (Figure 2). This modality includes an offloading component that transfers weight from the foot to the lower leg and a shoe (FootForte; Pulse Flow Technologies, Inc) with an insert (Aresta insole [Pulse Flow Technologies, Inc] with D30 technology [D30]). The offloading component includes a bladder at the level of the calf and the arch of the foot that provides intermittent compression in a 20-second cycle (1 second of inflation followed by a 19-second deflation). A sensor located in the shin section of the offloading component records the number of hours the device is worn and provides an audible alarm if the device is worn incorrectly. The patient consented to use of the novel device and weekly visits to the foot clinic where the DFU was assessed, debrided, photographed, and dressed. At each visit, the number of hours the device had been used was downloaded and recorded. 

Pressure reduction as noted by reduced callus formation was seen at just over 2 weeks upon initiation of this new treatment approach (Figure 3). The patient was instructed to continue use of the device to allow maturation of the newly epithelialized DFU. Device modifications were made after the first month of treatment to accommodate for the patient’s leg length and provide a more comfortable fit. At the 2-month follow-up, the patient admitted to removing the device to drive and not reapplying it until the evening. Usage data downloaded from the device confirmed that the patient was wearing the device for only 2 hours a day. Clinical examination revealed increased callus to the area of previous ulceration (Figure 3). Subsequent recurrent ulceration to the area occurred 7 weeks after patient noncompliance with offloading modality use. (Figure 4). Local wound care and use of the offloading device was restarted. The importance of compliance with device use was emphasized to the patient. An additional pair of shoes and insoles was dispensed for use when the patient drove to ensure improved continuity of effective offloading when driving. 

Resolution of the recurrent DFU occurred at 5 months (Figure 5). The patient continued receiving routine foot care and now wears only the shoes and insoles provided, without use of the offloading component, thus breaking the 2-year DFU cycle of recurrence and resolution. Because the patient was able to maintain an ulcer-free state, the decision was made to proceed with reconstructive surgery to relocate the displaced digits and plantar fat pad, further minimizing the potential for DFU recurrence. The patient continued to use the prescribed shoes and inserts but without the offloading device and has remained free from DFU recurrence for more than 3 years. 

High-quality evidence has shown that use of footwear designed to mitigate plantar pressure rather than use of standard therapeutic footwear reduces the rate of recurrence of DFU, specifically for plantar metatarsal head DFUs.³ In the case presented here, the patient was seen on a regular basis for routine foot care and had been dispensed therapeutic footwear and orthoses for ongoing use. Recurrence persisted for 2 years despite these interventions. Management with a novel offloading device, which can be used during and after treatment, broke the cycle of recurrence. Use of this device allowed for offloading and increased circulation to assist with wound healing and resulted in improved patient comfort and satisfaction, which enhanced compliance with use. Compliance with use of both the novel offloading device and subsequently prescribed medical footwear and orthoses resulted in the longest duration of ulcer-free outcome, which made it possible to perform corrective surgery to further minimize the potential for recurrence of DFU.

Given that patients with a history of DFU are at the highest risk for recurrence, the concept of patients being in remission has been discussed.³ This concepts moves from thinking of a DFU as healed to a patient with a healed DFU that is at risk for recurrence if proper preventative measures are not employed. Measures to prevent recurrence are imperative as the number of patients in ulcer remission far outnumber those with an active DFU. The high rate of DFU recurrence has been attributed to physical, behavioral, and mechanical factors. Physical factors such as peripheral arterial disease and foot deformity may be improved through surgical intervention, whereas peripheral neuropathy and reduced tensile strength of the skin after resolution of DFU cannot. Behavior modification can be challenging. Patient noncompliance with the lifelong need for routine foot care and appropriate footwear use is a major factor leading to recurrence.³ A common patient misconception is that once a wound has resolved no further treatment is necessary. They do not consider the need for prevention of ulcer recurrence. This is a significant causal factor in patients not continuing use of appropriate shoe gear in the manner to prevent recurrent ulceration. Failure to understand this necessity is a greater risk factor for recurrent ulceration than biological sex, diabetes duration, or history of ulceration. Individualized patient education to improve this misconception may be the method for ensuring lifelong compliance with appropriate footwear use and foot care.²⁶ Typical offloading modalities used may conflict with a patient’s activities of daily living, especially if patients need or want to work during treatment.^14,22,25 Prioritizing patient comfort and satisfaction may also increase compliance with use of these devices, as in the case report presented here.  

In addition, the novel offloading device used for this patient incorporated calf and foot compression to enhance circulation, which is critical to wound resolution. Compared with intermittent pneumatic compression of either the calf or the foot alone, use of combined intermittent pneumatic compression of both the foot and the calf has been shown to result in increased flow velocities of the major arteries of the lower extremity.²⁷ Combined intermittent pneumatic compression of the calf and the foot has also been shown to have effects on the microvasculature of the foot, with prolonged dilatation of capillaries to the hallux.²⁸ Inclusion of intermittent pneumatic compression of the foot and the calf in this novel offloading device can only serve to assist in expeditious wound resolution, as seen in the case presented here. 

The major limitation of this case report is that the findings may be subject to bias and inability to generalize findings.²⁹ However, the concepts employed by the novel offloading device utilized in this case are well studied and proven to accelerate DFU resolution and prevent recurrence. While modalities used for offloading vary, it remains a standard of care in treatment of plantar DFUs due to its tremendous benefit on healing. The total contact cast is considered the gold standard for offloading, but several operational and patient-related barriers limit its use.³⁰ These patient barriers include conditions that contraindicate its use, such as ischemia or deep ulceration with infection, but namely boil down to patient intolerance of the therapy. 

Patient compliance also plays an important role in recurrence prevention. Improved patient education on the importance of lifelong proper shoe gear use, incorporation of smart technology to track compliance, and focus on patient satisfaction with the devices utilized, both for wound resolution and lifelong protection, may improve reduction in DFU recurrence rates.³ The intermittent pneumatic compression incorporated in this device also has been shown to have positive changes to the macrovasculature and microvasculature of the foot, which may also assist in accelerated wound healing.^27,28 

Combination of offloading, smart technology for compliance monitoring, intermittent pneumatic compression, ability to continue use of the associated pair of therapeutic shoes and inserts upon wound resolution, and enhanced patient satisfaction make the novel offloading modality presented in this report an intriguing modality to employ in combating DFU occurrence and recurrence.

The author would like to thank Dr Valerie Marmolejo, DPM, MS, for her contributions to the writing of the manuscript.

Author: Caroline Lyons, MSc, BSc (Hon) PodiatryAffiliations: ¹Wirral University Teaching Hospital, Birkenhead, England; and ²Arrowe Park Hospital, Birkenhead, England

Correspondence: Valerie Marmolejo, DPM, MS, Medical Writer, Scriptum Medica, Medical Writing; vlsdpm@gmail.com 

Disclosure: The author discloses no financial or other conflicts of interest.