Case Studies In Unusual Wounds
Given the preponderance of wounds one sees in practice, podiatrists inevitably see wounds of an unusual shape or wounds that demonstrate a unique pattern of soft tissue trauma. Accordingly, this author discusses underlying factors with these abnormal presentations and offers a few challenging case studies involving unusual wounds.
The management of lower extremity ulcerations is a complex task. It is necessary that physicians involved in wound care and limb preservation address both the systemic and local factors that interact to generate significant comorbidity and mortality in this complex patient population.
Numerous authors have previously described the efficacy of an interdisciplinary team approach to specifically address the common factors that combine to lead to ulceration, wound infection and subsequent lower extremity amputation.1,2 Research has demonstrated that such interdisciplinary models are highly effective in reducing the incidence of non-traumatic amputations around the world.3
In the management of lower extremity ulcerations, clinicians involved in lower extremity wound care can appreciate a harmony of themes — wounds that present in similar ways and respond in a consistent fashion — and one can appreciate that these wound presentations are a consequence of complex interactions of various risk factors. These risk factors include neuropathy, vasculopathy, musculoskeletal deformity and trauma associated with repetitive stress across a wound site.4-6 To ensure progression through wound healing to wound closure, clinicians must address each of these factors.
Despite the commonality of wound presentation, one must remember that each patient is unique and consequently each wound can be similarly unique. Often, unusual wounds require a fresh approach and a new paradigm to effectively progress toward wound healing.
What You Should Know About The Chronic Wound Environment
Prior to any discussion regarding unusual wounds, it is valuable to discuss the central concepts associated with wound healing and those factors that contribute to wound chronicity. Sheehan and colleagues found that a wound that does not reduce in area (simple length x width) by at least 50 percent in four weeks has a greater than 90 percent likelihood of not healing at 12 weeks.7 Therefore, should a wound appear to be progressing too slowly, it is appropriate to alter the treatment algorithm as necessary in an effort to restart healing.5,8
In those instances in which delayed healing occurs, this delay is commonly secondary to multifactorial etiology and pathological variations in the wound environment. In addition to being populated largely by senescent cells, chronic wounds commonly demonstrate increased levels of inflammatory cells as well as imbalances in the endogenous proteases found in the wound bed. These enzymatic imbalances lead to persistent degradation of the provisional wound matrix components that are necessary for wound healing.
Among these proteases, matrix metalloproteases (MMPs) play an important role in damaging the extracellular matrix and the extracellular growth factors present in a chronic wound.9,10 These MMPs are synthesized by multiple cell types, including neutrophils, fibroblasts and macrophages, at the direction of chemical mediators such as inflammatory cytokines. In the acute wound environment, MMPs function to debride away denatured elements of the extracellular matrix, thus exposing areas of the intact functional matrix that are needed for wound healing.
This process is highly regulated and controlled via tissue inhibitors of metalloproteases (TIMPs). In chronic wounds, in addition to an excess number of MMPs, there is a failure in the regulation of protease activity between the MMPs and TIMPs, which can result in further degradation of the extracellular matrix.11,12 This is followed by the destruction of growth factors, inhibition of angiogenesis and breakdown of granulation tissue.
Currently, common wound healing modalities seek to address these imbalances and new advanced wound healing modalities, such as bioengineered alternative tissues, provide dermoinductive and dermoconductive wound healing properties to help convert a stagnant wound into an acute, healing wound.13,14