“Spare Parts” for Foot Wound Reconstruction: A Report of 2 Cases

The concept of the wound reconstructive ladder can be sequentially applied to the simplest and most complex wound presentations. Depending on the defect’s severity and condition, soft tissue coverage can range anywhere from primary healing to the utilization of a free flap.¹ With any closure, there are advantages and disadvantages to be considered for optimal outcomes influenced by the length of treatment, location of wound, patient comorbidities, and surgeon preference.² Overall, the goal of repair is to select the technique with the best long-term outcomes depending on the presentation and etiology of the wound. This is often achieved with the fundamental principle of “replacing like with like” to restore similar structure and functionality to the area.³ 

Complicated foot wounds, particularly on the plantar surface, present a great challenge to plastic and reconstructive surgeons. The foot is one of the few areas that experiences constant daily stress and movement, particularly with the pressures of ambulation. This strain is mitigated by the foot’s unique soft tissue anatomy, which includes a thickened stratum corneum of glabrous skin and epidermal/dermal attachments to the underlying plantar fascia.⁴ Due to its distinct composition, limited availability, and restricted rotational ability of local plantar flaps, reconstruction of foot wounds can simply become complex.⁵ Additionally, poor circulation, the presence of infection, and peripheral neuropathy from comorbidities seen in distal extremities further complicate foot wound healing.⁶ 

An important concept in limb reconstruction is “spare parts” surgery. This involves the rectification of viable tissue from unsalvageable parts of the injured limb. Spare parts harvested from these areas can be used to provide coverage and reestablish functionality in the form of individual tissue grafts, vascularized flaps, or digit transposition.⁷ In areas of anatomical intricacy and limited tissue availability, such as the foot, spare parts surgery can be a critical tool for successful reconstruction. This technique can minimize donor morbidity and replace tissue with similar purpose, leading to improved long-term results.⁸ Here, we report on 2 cases in which spare parts foot reconstruction was used to manage challenging defects. 

A 67-year-old man with a history of diabetes and coronary artery bypass graft presented with extensive right forefoot gangrene involving the first metatarsal head. At evaluation, vascular status was noted to be satisfactory with right ankle-brachial index of 0.8. However, diabetes-related microangiopathy was diagnosed. Initial debridement removed the necrotic soft tissue and distal first metatarsal head with osteomyelitis (Figure 1A). A peripherally inserted central catheter was then placed for delivery of intravenous vancomycin for staphylococcal infection. For 2 weeks, daily wet and moist, nonsterile gauze dressing changes were applied. During a second procedure, soft tissue debridement was performed while the proximal opening was closed via undermined skin flaps, and the distal defect was closed with a fillet pedicle flap of the great right toe (Figure 1B). Within a month, the wound completely healed, and the patient was able to ambulate (Figure 1C).⁹ 

An 84-year-old woman initially presented to the vascular service with right forefoot gangrene involving her right great toe (Figure 2A).  Bilateral arterial duplex ultrasound of the lower extremities revealed hemodynamically significant stenosis of the right superficial femoral artery and occlusion of the left superficial femoral artery. Angiogram revealed an occluded right superficial femoral artery, which was subsequently stented to improve limb perfusion (Figure 2B). After revascularization, there was worsening dry gangrenous changes noted to toes 2 through 5, with no changes to the great right toe. The right dorsalis pedis pulse was not palpable. Ankle brachial indexes of the right posterior tibialis and dorsalis pedis were 0.90 and 0.78, respectively, after stent placement. The patient was offered a below-knee amputation, which she declined to undergo. This then led to a plastic surgery consult, ultimately resulting in a right transmetatarsal amputation after the gangrenous tissue over the right forefoot was debrided (Figure 2C). Closure of the transmetatarsal amputation included a plantar great toe flap attached to a plantar foot flap. The dorsal skin of the spared great toe was harvested for a viable 4 × 2-cm full-thickness skin graft and sutured with 3-0 Vicryl (Ethicon Inc) to the medial side of the dorsal forefoot wound (Figure 2D). Negative-pressure wound therapy was initiated on the remaining 2 × 5-cm dorsal wound on the lateral side, and healing progressed (Figure 2E). After 2 months of follow-up, the wound completely healed, and the patient was able to ambulate with therapy and padded orthopedics (Figure 2F). 

Ideal foot reconstruction incorporates adequate soft tissue coverage while keeping durability in mind, which can be accomplished via “spare parts” surgery. Depending on the presenting foot defect, salvaged material can include skin, bone, nerve, artery, and vein for grafting or vascularized composite flaps.⁷ For effective reconstruction, these materials must exhibit anatomical integrity and permissible ischemia time for revascularization, and they serve a better purpose when used for reconstruction versus being left in its original location. Reconstructive surgical planning of spare parts utilization relies on the application of foundational principles, but also the in-depth understanding, precise judgment, and ability to contrive composite flaps from suboptimal conditions.¹⁰ 

Fillet flaps acquired from nonfunctioning tissue are commonly used to cover major defects in limb injuries. Given there is suitable tissue nearby, these “spare parts” can be repurposed as pedicle, island, or microvascular free flaps.⁷ In case 1, amputation of the hallux was unavoidable due to substantial forefoot necrosis observed on initial debridement. However, the vascularity of the great right toe’s soft tissue was sufficient, which was repurposed into a fillet pedicle flap to adequately cover the distal foot defect.¹⁰ Similarly, the patient in case 2 had preserved vascularity and underwent transmetatarsal amputation. A plantar foot flap was then met with a plantar great toe flap to cover the dorsal defect of the wound with the addition of a full-thickness skin graft recovered from the dorsal great toe. 

Both cases avoided unnecessary harvesting from nonaffected sites that would contribute to donor-site morbidity. These approaches also closed the foot defects with analogous tissue built to withstand the functional demands of ambulation. With limited skin availability and distinct functionality, the repurposing of spare parts provides a practical option for soft tissue coverage of foot wounds. The purpose of these cases is to share our institution’s experience of the spare parts concept in complex wound foot reconstruction in the setting of significant underlying vascular disease. The success of this strategy greatly relies on the vascular integrity of not only the scavenged tissue but also the site of implantation. In patients with compromised vascular status, the healing and success of spare parts surgery becomes complicated even with appropriate planning and execution; habituated awareness and clinical judgment is required for the best outcomes. In these 2 cases, the spare parts technique enabled these patients to experience less donor morbidity while escaping the need for more proximal amputation for sufficient wound coverage. With appropriate healing and therapy, both patients were able regain bipedal ambulatory ability. 

We report 2 cases of complex foot surgical wounds utilizing spare part foot reconstruction. Spare parts reconstruction provides a method of closure for complicated soft tissue defects of the foot. Maintaining the concept of replacing “like-with-like,” skin of similar texture and functionality can be reclaimed in areas with little tissue to spare. Furthermore, this technique limits the need for harvesting from additional donor sites and subsequently leads to less patient morbidity, especially in areas of uninjured tissue. These case reports demonstrate the use of an effective technique for complicated soft tissue wounds of the foot, which ultimately optimized our patients’ outcomes.