By Justine Tansley, MRCPod; Richard Collings, PhD, DSc (Hons); Jennifer Williams, BSc (Hons); and Joanne Paton, PhD, MSc
The management of DFUs complicated by the effects of lower limb edema is clinically challenging, and both conditions can require a multifaceted treatment approach.
Lower limb edema is a common comorbidity in those with diabetes and foot ulceration and is linked with increased amputation risk. There is no current guidance for the treatment of concurrent diabetic foot ulcers (DFUs) and lower limb edema, leading to uncertainty around the safety and efficacy of combination approaches incorporating offloading and compression therapies. To determine indications and contraindications for such strategies and identify any other supplementary treatment approaches, a scoping review was undertaken to map the evidence relating to offloading and compression therapy strategies to treat both DFU and lower limb edema in combination.
Methods
Following the Joanna Briggs Institute (JBI) and PRISMA—Scoping Review (ScR) guidance, this review included published and unpublished literature from inception to April 2022. Literature was sourced using electronic databases including Cochrane Library, PubMed, CINAHL, AMED; websites; professional journals, and reference lists of included literature. Eligible literature discussed the management of both DFUs and lower limb edema and included at least 1 of the treatment strategies of interest. Data extraction involved recording any suggested offloading, compression therapy, or supplementary treatment strategies and any suggested indications, contraindications and cautions for their use.
Results
Five hundred twenty-two publications were found relating to the management of DFUs with an offloading strategy or the management of lower limb edema with compression therapy, of which 51 were eligible for inclusion in the review. The majority of the excluded publications did not discuss the situation where DFUs and lower limb edema present concurrently.
Discussion
A scoping review was carried out which aimed to establish what available offloading and compression therapy strategies exist to manage a DFU complicated by the effects of lower limb edema
Offloading Strategies
International guidance recommends that a non-removable knee-high cast, such as a total contact cast (TCC), is used as a first-line treatment to offload a DFU, unless contraindicated. This scoping review found 1 retrospective cohort study suggesting that lower limb edema may be 1 of these contraindications. The study suggests that a TCC is not suitable for those with a DFU and lower limb edema as an increased number of adverse events was reported in this population. It was agreed that such devices were primarily intended to assist with DFU healing, yet there were opposing arguments about their use in the presence of edema and associated complications. Definitive direction regarding the indications and contraindications for the use of a TCC in these circumstances was lacking from the evidence.
Current guidance also recommends that a knee-high walking cast may be used as a second-line alternative if a non-removable TCC is not tolerated. Some of the literature suggests that a removable knee-high walking cast should accommodate lower limb edema for limb protection, yet other literature supports the use of a removable pneumatic walker cast, to offload a foot wound and reduce edema. Neither suggestion was supported by scientific studies or other forms of evidence. There was a lack of information regarding the use of knee-high removable casts/walkers to treat a DFU where lower limb edema was present and no discussion was found concerning appropriate use or contraindications in these circumstances.
An ankle-high removable cast is a third-line recommendation, if a knee-high cast is not tolerated or contraindicated. The International Working Group for the Diabetic Foot acknowledges this recommendation in its guidance is not supported by high-quality evidence. The literature found by the review, suggests that an ankle-high design is intended to allow for treatment of a leg condition, yet it is difficult to make a definite conclusion as to the suitability of this strategy to treat a DFU in the presence of lower limb edema. No scientific studies were found demonstrating that these offloading devices could be safely and effectively used in combination with a leg treatment such as compression therapy.
Two further strategies were found that are not included in any current guidance: The use of a back-slab style cast to offload a DFU and accommodate any fluctuations in lower limb edema; and a heel offloading device designed to relieve pressure from a heel wound when a person is lying prone, which may accommodate leg swelling but it is not suitable if leg wounds or exudate are present. Both strategies were not supported by scientific studies or other forms of high-level evidence.
Compression Therapy Strategies
Although there is no current guidance for the use of compression therapy to manage lower limb edema in the presence of a DFU, benefits for its use are acknowledged in the literature. This scoping review found that full-strength multi-layer bandaging may be used in those without arterial compromise; reduced-strength bandaging may be used in those with reduced arterial blood supply; and a wound was unlikely to heal if there was severe arterial compromise as compression is likely to further reduce blood flow. Several case studies were found all sharing successful practice where DFU management was complicated by lower limb edema. All of the case studies introduced compression bandaging to promote wound healing. However, reports of failed or ineffective cases and their circumstances were not found, leaving unanswered questions about the true safety and effectiveness of compression bandaging in these circumstances.
This review found literature which suggests that compression hosiery could be a useful way to manage lower limb edema where a DFU is present. Two used participants with diabetes, with or without mild to moderate peripheral arterial disease (PAD), to test the safety of compression hosiery. Both studies reported that there was no effect on arterial blood supply when hosiery was worn and after removal. Participants with large wounds, copious amounts of exudate, and infection were excluded, which suggests this strategy may not be appropriate for those with more severe complex wounds.
This review found literature that suggests the use of pneumatic compression to manage lower limb edema where a DFU was also present. Wound healing and prevention of major amputation were the main outcomes of interest. The majority of the literature agreed that pneumatic compression could be used to promote healing in wounds of any etiology, including in those with severe PAD where re-vascularization is not possible. However, the literature acknowledges the supporting evidence to be of low methodological quality.
Supplementary Strategies
This scoping review found 16 supplementary strategies to manage a DFU and lower limb edema where both conditions present together: integrated working, leg elevation, patient-specific care plan, dermal replacement allograft, elbow crutches, exercise (non-specific), Theraband, manual lymphatic drainage, weight control, wound scoring tools, bed rest, general skin care, neuromuscular taping, patient education, pharmacological, and surgical. Integrated working, patient-specific treatment plans, and the use of wound and leg assessment tools were popular in expert opinion. The rationale for these 3 strategies was they could be applied to any clinical situation including where complex comorbidities exist that impact the lower limb, used to improve the quality of treatment planning and subsequent care and outcomes. However, all of the supplementary strategies found by this scoping review, lacked a scientific basis to support their use in a combination management approach of a DFU and lower limb edema.
Conclusions
Most literature focused on edema management with compression therapy to conclude that compression therapy should be avoided in the presence of severe PAD. Less literature was found regarding offloading strategies, but it was recommended that knee-high devices should be used with caution when offloading DFUs in those with lower limb edema. Treatment options to manage both conditions concurrently were identified as a research gap. Integrated working between specialist healthcare teams was the supplementary strategy most frequently recommended. In the absence of a definitive treatment solution, clinicians are encouraged to use clinical reasoning along with support from specialist peers to establish the best, individualized treatment approach for their patients.
Justine Tansley, MRCPod, is an Honorary Research Associate with the University of Plymouth School of Health Professions (Faculty of Health) and works with the podiatry team with the Torbay and South Devon National Health Service (NHS) Foundation Trust, Torquay, United Kingdom.
Richard Collings, PhD, BSc (Hons) in Podiatry, is an Honorary Clinical Research Fellow with the University of Plymouth School of Health Professions (Faculty of Health), and currently works as a team lead podiatrist with the Torbay and South Devon NHS Foundation Trust, Torquay, United Kingdom.
Jennifer Williams, BSc (Hons) in Podiatry, is an Honorary Clinical Research Associate with the University of Plymouth School of Health Professions (Faculty of Health) and works with the podiatry team with the Torbay and South Devon National Health Service (NHS) Foundation Trust, Torquay, United Kingdom.
Joanne Paton, PhD, MSc with distinction in Podiatric Biomechanics, is an Associate Professor of Podiatry with the University of Plymouth School of Health Professions (Faculty of Health), United Kingdom.
Plantar Pressure Thresholds as DFU Prevention Strategy
The development of ulcers in the plantar region of the diabetic foot originates mainly from sites subjected to high pressure. The monitoring of these events using maximum allowable pressure thresholds is a fundamental procedure in the prevention of ulceration and its recurrence. The aim of this systematic review was to identify data in the literature that reveal an objective threshold of plantar pressure in the diabetic foot, where pressure is classified as promoting ulceration. The aim is not to determine the best and only pressure threshold for ulceration, but rather to clarify the threshold values most used in clinical practice and research, also considering the devices used and possible applications for offloading plantar pressure.
The search was performed in 3 electronic databases, using the PRISMA methodology, for studies that used a pressure threshold to minimize the risk of ulceration in the diabetic foot. The selected studies were subjected to eligibility criteria.
Twenty-six studies were included in this review. Seven thresholds were identified, 5 of which are intended for the inside of the shoe: a threshold of average peak pressure of 200 kPa; 25 % and 40–80 % reduction from initial baseline pressure; 32–35 mm Hg for a capillary perfusion pressure; and a matrix of thresholds based on patient risk, shoe size and foot region (Table). Two other thresholds are intended for the barefoot, 450 and 750 kPa. The threshold of 200 kPa of pressure inside the shoe is the most agreed upon among the studies. Regarding the prevention of ulceration and its recurrence, the efficacy of the proposed threshold matrix and the threshold of reducing baseline pressure by 40–80% has not yet been evaluated, and the evidence for the remaining thresholds still needs further studies.
Conclusions: Some heterogeneity was found in the studies, especially regarding the measurement systems used, the number of regions of interest and the number of steps to be considered for the threshold. Even so, this review reveals the way forward to obtain a threshold indicative of an effective steppingstone in the prevention of diabetic foot ulcer. Furthermore, it is important to highlight the need for a next stage in research, which could focus on additional refinements, such as determining specific thresholds based on the most critical locations in the plantar region while considering foot anatomy variations (such as size, type, deformities, among others). This additional step could be an important contribution to a more precise approach to preventing diabetic foot ulcers based on a certain threshold.
Source: Castro-Martins P, Marques A, Coelho L, Vaz M, Costa JT. Plantar pressure thresholds as a strategy to prevent diabetic foot ulcers: A systematic review. Heliyon. 2024;10(4):e26161. doi: 10.1016/j.heliyon.2024.e26161.
This article has been excerpted from “Offloading and compression therapy strategies to treat DFUs complicated by lower limb edema: a scoping review.” J Foot Ankle Res. 2023;16(1):56. doi: 10.1186/s13047-023-00659-3. PMID: 37674176; PMCID: PMC10481591. Editing has occurred, including the renumbering or removal of tables, and references have been removed for brevity. Use is per CC 4.0 International Licenses.
