Medical history
A diabetic patient with a wound in the foot and ankle has a wound healing stuck in the inflammatory phase. The presence of chronic infection on the wound surface, which is filled with a large amount of proteins and growth factors, are factors that keep the wound in an inactive phase. Local and global factors prevent the transition of the wound from a chronic inflammatory to an acute state (a state that plays an active role in the normal wound healing process).
Due to the poor biomechanical stability of the diabetic foot, acute or repeated injuries often result in ulcer development. In addition, the presence of persistent abnormal raw stress, neuropathy, infection, ischemia, poor immune mechanisms and nutritional deficiencies on the surface of the ulcer with higher sugar content causes the ulcer to fail to heal. As a result, acute wounds turn chronic.
Wound healing in diabetic patients is strongly influenced by blood glucose levels greater than 300 MG/dL, which reduces the bactericidal capacity of leukocytes and directly affects wound healing. High blood glucose also causes joint and tendon stiffness by binding to collagen and reducing its intrinsic elasticity. Approximately 60% of diabetic ulcers lack blood supply due to the presence of peripheral vascular disease. Typically, atherosclerosis occurs in the lower s artery including the anterior tibial artery, posterior tibial artery and peroneal artery. In addition, due to high blood glucose levels, sugar binding to red blood cells causes increased blood viscosity and decreased red blood cell deformability, resulting in reduced capillary blood flow and decreased oxygen consumption in local tissues.
The entire history can be obtained from the patient and his or her family, emergency physician, and questioning physician to help determine the cause of the wound (usually trauma) and the timing of the wound. Trauma is usually associated with excessive local pressure increase due to abnormal biological stress during walking, shoe abrasion, penetrating injuries, and burns. In this case, the patient needs to be treated with tetanus immunization (if indicated for revaccination). It is important to determine what kind of treatment the patient has received, because certain specific medications can make the wound chronic, such as the use of hydrogen peroxide, 10% iodine, sodium hypochlorite solution, etc.
In addition, attention should be paid to cardiac, neurological, renal and ocular symptoms that may occur as a result of atherosclerosis. For patients who need dialysis, the initial dialysis time and type of dialysis should be recorded. Assess venous circulation by blood clotting abnormalities, liver disease, heart failure, venous thrombosis, and pulmonary embolism. To understand the degree of neurological pathology: including sensory loss, muscle weakness and loss of sweating function. Check the patient’s ability to detect and control blood glucose. Finally, assess the patient’s nutritional status including recent weight gain or loss and diet quality. The patient’s history of smoking, medication use and allergies is recorded.
Take a social history to determine the patient’s mobility, the ability of the family to provide assistance and the type of work the patient does. This information can help the surgeon understand the patient’s compliance with the treatment approach. This is because the patient may endure a period of inactivity for up to 6 months during treatment of the wound (e.g., llizarov treatment for Charcot’s collapse). Poor compliance is the largest single cause (>20%) in terms of factors causing postoperative complications.
Physical examination
The ulcer was carefully evaluated by measuring its area and depth, area = long axis of the ulcer * wide axis, and depth was assessed by the level of soft tissue involved in the ulcer: epidermis, dermis, subcutaneous fat, deep fascia, muscle, tendon, joint capsule, joint and bone. A metal probe helps to determine the depth of the ulcer, and if bone is probed, the incidence of osteomyelitis is up to 85%. If tendons are involved, there is a high probability that the infection will spread to the proximal or distal end of the tendon, and the surgeon should carefully examine the distal and proximal segments of the suspected tendon sheath. If there is a greater likelihood of distal infection spreading proximally, the proximal tendon sheaths that are susceptible to spread (e.g., extensor support band, ankle canal) should be examined. Photograph the ulcer at the same time.
If cellulitis is present, the borders of the erythema should be traced and documented (to the exact month, day, and time) with unfading ink. After deep tissue culture and administration of broad-spectrum antibiotics, the expansion and elimination of the erythema is monitored without interruption. If insufficient antibiotics are administered, or if the wound is not adequately debrided, inflammation can cross the boundaries traced by the inkblot after 4-6 hours.
It is important to distinguish cellulitis from redness caused by chronic ulcers and chronic ischemia. If the erythema disappears after elevating the affected limb above the plane of the heart, the erythema is subordinate, usually not due to inflammation, and the skin may appear wrinkled. If the erythema persists and there is cellulitis around the wound, antibiotic therapy with or without surgical debridement is required. Subordinate erythema can also occur after the initial surgery and should be differentiated from postoperative cellulitis.
Local blood flow is assessed by palpating the arterial pulses and using portable arterial Doppler. If the anterior and posterior tibial arteries can be palpated, this indicates adequate blood flow. If one arterial fluctuation cannot be palpated, the arterial Doppler should be used for evaluation, with a triphasic Doppler signal suggesting normal flow, a diphasic Doppler signal suggesting inadequate flow, and a single one requiring further study. If poor flow is suspected, Doppler must be performed. If the flow is inadequate, a consultation with an angiologist (specializing in angioplasty operations) should be sought.
Patient sensation must be evaluated; if the patient cannot feel a pressure of 10 g (5.07 Semmes-Weinstein-monofilament), it suggests a lack of protective sensation. Injury can be caused when local pressure is too high (prolonged recumbent position, wearing tight shoes, clothing or skirts; abnormal biomechanics or foreign bodies trapped in the shoe). Abnormal biomechanics can be caused by abnormal motor function, abnormal bone structure, or a tight Achilles tendon causing localized high pressure on the bottom of the foot during walking.
If the patient has a sensory deficit, ulceration can occur in these stress concentrated areas due to repeated abnormal stresses during normal daily activities (walking approximately 1000 steps per person per day). The claw toe profile caused by intrinsic foot muscle lesions may reflect motor nerve disease. Bony abnormalities of the foot including metatarsal head protrusion and Charcot joint collapse can be evaluated by weight-bearing x-ray of the foot. Because diabetes affects the elasticity of the Achilles tendon, it can be carefully evaluated by dorsal foot extension test and posterior rotation test.
If the dorsiflexion of the foot exceeds 15 degrees in knee extension and flexion, the Achilles tendon is well elastic. If dorsiflexion is only possible in knee flexion, the gastrocnemius portion of the Achilles tendon is too tight. If dorsiflexion is not possible with the foot in either knee flexion or extension, both components of the Achilles tendon are overtight.
Differential diagnosis.
Ischemia
cellulitis with subordinate erythema
Osteomyelitis
Biomechanical abnormalities
Ancillary tests.
Laboratory tests were first performed to determine the patient’s immediate blood glucose and glycosylated hemoglobin. Poor glycemic control is indicated when glycosylated hemoglobin exceeds 6% (6% = blood glucose level of 135 mg/L, 7% = 170 mg/L, 8% = 205 mg/L, 9% = 240 mg/L, 10% = 275 mg/ dL, 11% = 310 mg/dL, 12% = 345 mg/ dL). If the blood glucose level is high and the glycosylated hemoglobin level is low it indicates acute infection.
Leukocytes and their categorical counts are useful for monitoring systemic infections. In patients with diabetic renal failure, cell counts can appear falsely normal. Regular knowledge of the erythrocyte sedimentation rate can be useful in monitoring the treatment of infections. X-rays are useful for evaluating the structure of the bone, but they are not useful for monitoring acute osteomyelitis, which takes about 3 weeks after onset to show up on radiographs.
MRI and nuclear scans are often not necessary if the surgeon intends to evaluate the affected bone during debridement. However, these examinations can be helpful when the extent of infection of the bone is uncertain or when other bones are involved. Non-invasive vascular examinations are helpful to understand the blood flow to the foot. In diabetic patients, the ankle-brachial index is often less accurate due to arterial calcification.
Since the finger arteries are not usually calcified, a toe artery pressure greater than 50 mmHg is often indicative of an adequate blood supply. Tissue partial pressure of oxygen can also be a good response to blood flow when the laboratory examination is reliable. Below 20 mmHg suggests poor healing. 20 to 40 mmHG suggests possible healing. above 40 mmHg suggests good healing.
Treatment.
Principles of treatment
The aim of treatment is to convert chronic wounds into neoepithelialized acute wounds with no swelling of the borders and healthy granulation tissue. Reconstruction of simple flaps has a 90% success rate, while complex flap reconstruction has a 10% success rate. Obtaining good healing requires proper diagnosis, ensuring a good local blood supply, thorough debridement, correction of abnormal stresses and nourishing the wound until signs of healing appear. It is important to preserve as much healthy tissue as possible to increase the chances of reconstruction.
If the chronic diabetic wound involves more complex tissues, this requires a holistic team approach to treatment. The diabetologist regulates blood sugar, the infectious disease specialist optimizes anti-inflammatory therapy, the foot and ankle specialist corrects abnormal biomechanics, the vascular specialist improves local blood supply, the trauma specialist converts the chronic wound into a healthy healing wound, and the orthopedic specialist uses reconstructive flaps to close the wound. There are usually two or more ways to treat diabetic ulcers in each specialty.
If the patient’s blood supply is uncertain or inadequate, debridement surgery needs to be delayed until blood flow to the affected area improves. However, if the necrotic wound shows signs of gas gangrene, cellulitis spreading, or necrotizing fasciitis, local blood flow is disregarded and prompt surgical debridement is performed. Prior to revascularization surgery, wound dressing changes may be performed to maintain cleanliness, and if progressive gangrene is present, local debridement with maggots may be performed every other day to minimize removal of viable tissue. After successful surgery, oxygen therapy is used for 4 to 10 days to increase the local oxygen content of the tissue. Next, final debridement and intensive wound care are performed depending on conditions.
To reduce plantar pressure on the forefoot during walking in the clubfoot, open or percutaneous Achilles tendon release may be performed to promote rapid healing of the forefoot plantar wound. Surgical correction of abnormal foot biomechanics is part of the treatment, and debridement and wound care would be meaningless without this procedure.
Debridement
Wound debridement is very important because tissue necrosis, foreign bodies and bacterial infection affect wound healing by producing or stimulating the release of proteases, collagenases and elastases. These substances disrupt normal tissue healing building blocks (e.g., chemotaxis, growth factors, growth factor receptors, and mitogens), cause bacterial colonization of the wound, and produce enzymes (which consume large amounts of scarce resources such as oxygen, nutrients, and building blocks) that interfere with wound healing. A retrospective analysis of the role of platelet-derived growth factors in chronic diabetic wound healing revealed that weekly debridement of the initial wound was more likely to heal than immediate debridement. Removal of factors that adversely affect wound healing will allow the wound to move out of the inflammatory phase into the proliferative phase.
Adequate wound debridement involves the removal of inactivated tissue down to healthy tissue. The body itself can remove any necrotic tissue, but the process is slow and unpredictable, especially in chronic wounds. Surgical debridement of wounds with maggots or agents is usually safe and effective. Once the diagnosis is established, the ulcer should be debrided and the local environment improved next.
Deep tissue cultures are first performed during surgery to allow for appropriate postoperative antibiotics, and several tissue cultures may be required to determine what tissues are involved. Aggressive postoperative wound care is performed to avoid bacterial contamination of the skin. Once the level of tissue involvement has been determined, a large number of targeted antibiotics can be administered. Deep tissue cultures are performed at each debridement to determine the effectiveness of antibiotic therapy.
Figure 1 A male diabetic patient with wet gangrene of the anterolateral foot. b The best debridement method is to perform successive thin excisions until normal tissue is revealed. c Thin the section more closely to normal tissue to minimize damage to healthy tissue. d Adequate debridement with excision of all necrotic tissue and the same principles for bone. e Show the excised tissue adjacent to normal tissue on the dressing.
Figure 2 A Complete debridement with maggots, preserving as much normal tissue as possible. b Change maggots every two days until no further necrotic tissue is present.
Figure 3 Venous agglutination is a good sign that the wound needs to be re-debrided
Figure 4 VAC device used as a dressing over normal tissue. A Skin wound dehiscence after below-knee amputation for which debridement does not allow wound closure B Placement of VAC dressing C Immobilization D Connection to a portable VAC device that the patient can take home.
If needed, wound debridement should be performed several times until the wound is considered clean and suitable for surgical reconstruction. The ideal surgical technique is to perform a laminar excision of the necrotic material down to the bleeding tissue (Figure 1). The wound is closely monitored and debridement is performed as soon as inactive tissue is present. Debridement agents may be used when surgical debridement is not tolerated or when only a small amount of tissue removal is required. However, these debriding agents may cause pain. Maggot debridement is a very effective method if the patient cannot tolerate surgery or debridement agents (Figure 2).
The problem I encountered was the training of other health care professionals in how to use this method. However, once the hospital accepts and signs the protocol, this method can be used routinely. When a septic reaction occurs against maggots, they should be removed promptly. This is of course a rare occurrence.
The proper application of antibiotics can reduce bacterial colonization between procedures, and dressings impregnated with silver ions or silver sulfadiazine work well for most wounds. For penicillin-resistant Staphylococcus aureus, mupirocin is helpful. Of course it can also be quickly tolerated by bacteria. For Pseudomonas spp. infections, 1/4 strength acetic acid, silver ionomer dressings and gentamicin are effective. For ulcers with less severe infection, bacitracin is sufficient.
Dressing options include placing beads of methylisobutyrate impregnated with 1 g vancomycin and 2.8 g tobramycin on the wound along with a closed dressing or vacuum device (VAQ device (KCI, San Antonio, TX). For methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci, maggots are the only effective biological agents. In addition, the use of a vacuum device after debridement can promote wound angiogenesis and reduce bacterial colonization. The use of negative pressure can rapidly reduce bacterial inoculum to below 105 within 4 days.
If the patient is allergic to antibiotics, they should be discontinued immediately. Allergic skin reactions may occur around the ulcer and may be treated with reasonable steroids at this time.
WHAT To DeRIDE
The key to debridement is the complete removal of inactivated tissue down to healthy tissue, and if the subcutaneous veins are clotted, this suggests that further debridement may be required (Figure 3). The skin edges should have bleeding spots and the subcutaneous fat should be bright yellow. The best approach is to excise the inactivated tissue in layers until normal healthy tissue is revealed (Figure 1). As normal tissue is approached, the thickness of the layer is gradually reduced to avoid damage to healthy tissue.
All sticky, softened tendons or fascia should be removed down to the firmer connective tissue. When dealing with larger tendons, the tendon surface can be scratched until the white tendon fibers are revealed and the texture of the normal tendon can be palpated. The skin distal and proximal to the ulcer is incised to expose the superficial soft tissue of the tendon, ensuring that all necrotic tendonous tissue is removed.
The exposed cartilage tissue at the base of the ulcer is excised. However, normal cartilage revealed in the debridement is not removed and the wound is closed directly.
The bone is transected or the inactivated bone is removed until healthy bleeding bone tissue is present. When dealing with larger bones, the bone is transected with a transeptor until blood flows out. When dealing with smaller long bones, a pendulum saw can be used to cut repeatedly in its sagittal position until normal-looking cancellous bone and cortical bone with blood flow are revealed. Since necrotic bone masses can be considered foreign bodies by the body, they should likewise be removed.
All foreign bodies located at the base of the wound should be removed as much as possible including fixations, prosthetic joints, sutures, mesh, and artificial vessels. This is sometimes not always the case when dealing with artificial vessels and surgical internal fixations. In some cases, the surgeon often operates in conjunction with other surgeons (e.g., vascular surgeons, plastic surgeons).
Negative vacuum pressure devices
Once the wound is clean and ready for revascularization, the wound can be covered with a negative vacuum device, which is applied to the wound through a closed suction mechanism that accelerates the growth of granulation tissue, kills wound bacteria, and reduces tissue edema. The exact mechanism of action is not yet cleared. However, (removing unfavorable factors) wound healing factors, reducing edema, increasing blood flow and altering cellular scaffolding play a role in wound sterilization and promoting tissue regeneration.
The vacuum negative pressure device consists of polyurethane ether foam sponge with small holes of 400-600 um in diameter. It can be placed directly on the ulcer surface (Figure 4). A non-collapsing vent tube surrounded by an adhesive dressing at the distal end is placed on the outer surface of the sea surface with an opening at the end in the foam sponge, and the sponge is trimmed with the adhesive dressing to fit the wound size. A pair of Mayo scissors is well suited for trimming the sponge shape.
After the sponge and exhaust are installed, they are secured with a waterproof adhesive film 3 to 5 cm beyond the skin edge. a filter is attached to the proximal end of the exhaust to regulate the vacuum pump. The air pump draws air so that the pressure on the wound surface is below atmospheric pressure. Multi-vacuum foam allows for uniform pressure across the wound. And the filtering device can collect the wound secretion fluid. The pressure can be applied continuously or intermittently at 125 mmHg below atmospheric pressure. Compared to continuous negative pressure, intermittent pressure has been found to stimulate faster formation of granulation tissue on the wound surface and to increase local blood flow continuously.
If the vacuum device is placed on a neurovascular bundle or tendon, an oil-impregnated gauze or silicone dressing should be placed between the vacuum sponge and the wound to reduce potential tissue damage. With prolonged use of the vacuum device, the wound can develop an odor. This can be solved in two ways:1 Place a hard tablet mixed with silver ions or a dressing with an absorbable effect between the sponge and the wound or stop using the vacuum device for 1 to 2 days, using 0.25% acetic acid or gauze dressing in between. If the wound still has ischemic or necrotic tissue, the use of the VAC device is prohibited, in that the former may lead to further ischemia, while the latter infection will develop further.
The VAC device changes the way chronic wounds are currently treated by helping to convert debridement into acute wounds, and can be used for almost all types of wounds if they are clean and well angiogenic. It allows physicians to choose a reconstruction plan rather than rushing treatment due to time constraints. Surgeons can use the device to promote wound healing rather than for reconstructive surgery.
The VAC device has shown its efficacy in fracture and joint exposure areas, and in addition, the author has found the combined use of local or tipped flaps to cover exposed joints or bone and for resting wounds undergoing skin grafting to be more effective. The VAC device can be used as a soft dressing in the implant area as well as in the flap donor area. Especially on irregular wounds, the use of the device guarantees a 95% viability rate.
Deciding when to close the wound
When all abnormal parameters around the wound have been corrected and all signs of inflammation have disappeared, secondary purposes allow wound healing, or closure of a delayed phase I wound for skin grafting or flap transfer.
There should not be any erythema around the wound itself. Cellulitis should not be confused with ischemia-induced subordinate erythema or redness from recent local surgery. If the surrounding redness subsides with elevation of the affected limb, the wound is subordinate; if it persists, it is suggestive of inflammation. If the healing ulcer was initially caused by massive cellulitis, there is usually a superficial depression of the skin in the area of the original cellulitis, and the patient’s pain gradually decreases as the inflammation subsides. However, pain relief is not more reliable than the resolution of erythema or sclerosis.
If sclerotia are present, the wound edges should be small. Once skin wrinkles are present at the wound edges, this indicates that the inflammation is beginning to mostly resolve. Sclerosis may also be seen in patients with immune deficiencies (e.g., renal failure, patients dependent on steroids,). The presence of granulation tissue in the wound suggests adequate local blood flow, a better periwound environment, and wound healing into a proliferative phase.
If quantitative bacterial examination is available, a bacterial load of less than 105 per gram of tissue suggests successful wound healing after skin grafting. In addition, if the graft on the wound is tightly adherent to the wound and pink in color, it suggests a clean wound. If new epithelial tissue is present around the wound, the wound is healthy and tends to heal.
Suturing Techniques
Suturing techniques include wound healing through secondary wound healing or closure of delayed phase I healing wounds, skin grafting, topical flaps, tipped flaps, and free skin flaps. Whenever possible, viable tissue is protected when debriding or applying medications prior to wound healing, as this aids in the final reconstructive surgery.
The wound area of a normal granulated wound is reduced by 10-15% per week. Wet dressings promote more rapid epithelial cell formation. The abnormal biomechanics that cause ulcer formation should be addressed. If the ulcer is located on the plantar aspect of the forefoot, correction of Achilles tendon contracture and toe hyperextension deformity is required, along with weight-bearing free forefoot. If the ulcer is close to the joint surface (ankle joint), joint braking should be performed. When dressing changes do not work, a variety of methods can be used for secondary wound healing.
Platelet-derived growth factors are effective in promoting wound healing when the patient has undergone angioplasty and regular wound debridement. Protein agglutinates must be removed from the wound surface before application of growth factors, as proteases present within the proteins can degrade them before the growth factors can take effect. Before each application of growth factors, the wound needs to be cleaned with a brown brush or soft bristle brush. Alternatively, if the wound is excessively painful when treated, a topical debridement containing collagenase can be applied between applications of growth factors.
Allografts (pig skin) Homografts (cadaver skin) can be used as an excellent, inexpensive, temporary wet dressing for healthy wounds. This dressing can provide a collagen scaffold for new tissue to grow into. This graft can maintain the viability of the layered thick skin graft piece if it is wound sterile and has substantial capillary formation before the organism develops rejection. In healthy patients, rejection occurs around day 9, and in immunodeficient patients, it may take up to 1 month.
Although, cultured skin substitutes are not skin grafts per se, they can provide a wet organic covering for the wound surface, which produces a large amount of growth factors beneath the wound surface. These flaps are modified by allowing live cells to implant and produce a collagen scaffold. The surface of the collagen scaffold is covered by a separate layer of epidermis. These products form 2 products commercially: combined epidermal-dermal grafts and pure dermal grafts, and have proven their effectiveness in venous stasis ulcers and diabetic ulcers.
For the cultured skin substitute to be effective, the wound needs to be clean and well vascularized, and the skin substitute should be treated like a skin graft, well adsorbed in the wound wound wound and kept immobile. the VAC device can be used as a dressing to reduce local edema and bacterial counts, while eliminating wound exudate. The replacement should be changed approximately every 4-6 weeks, or twice if needed. It is important to emphasize that this alternative is not particularly effective if the abnormal biomechanics that led to the development of the ulcer are not corrected.
Hyperbaric oxygen therapy allows for a concentrated supply of oxygen to the body for 90 min at 2 to 3 times the atmospheric pressure, which allows more oxygen to be dissolved in the plasma and transported to the edge of the ulcer (where hemoglobin may not reach), increasing the oxygen concentration around the ulcer and the oxygen gradient between the periphery and the center. The higher the oxygen gradient, the higher the chances of ulcer healing. Hyperbaric oxygen also promotes faster angiogenesis, collagen production and neoepithelialization. in addition, hyperbaric oxygen increases the bactericidal capacity of leukocytes.
Hyperbaric oxygen is only effective when there is adequate vascular blood flow, so before receiving hyperbaric oxygen therapy, patients need to undergo an oxygen excitation test to show the amount of increase in partial pressure of oxygen in the local tissues following an increase in oxygen content in the patient’s lungs. After inhalation of 100% pure oxygen, the partial pressure of oxygen in the skin should increase by at least 10 mmHg, and then sharply into a chamber of 2 atmospheres, the partial pressure of oxygen in the tissues should be greater than 300 mmHg. Otherwise, the treatment may be ineffective.
Surgeons need to closely monitor wound changes to ensure that the treatment is effective. Hyperbaric oxygen and platelet-derived growth factors will be more effective if they act in concert. Therefore, if the wound is clean and well vascularized, hyperbaric oxygen can be used to stimulate healing, and platelet-derived growth factors can accelerate healing.
Delayed Phase I Closure
After complete debridement of the wound edges, tension-free sutures should be performed and the wound edges must be kept in balance. Where the skin wound edges are too far apart to be sutured (as is often the case after fasciotomy), the use of a spring device or rubber ring may allow the wound edges to be aligned with each other. After careful alignment, the skin appears lax and the wound may be closed in one stage. Because the lower extremity consists of bone and peripheral surrounding soft tissue, it is easy to cause much annular pressure if the wound is sutured too tightly. When excessive pressure is suspected to affect end-tissue blood flow, end-tissue blood flow should be measured using Doppler.
Skin grafting
This is the simplest of all methods of covering wounds. If there is healthy granulation tissue at the base of the wound, a skin flap of 0.015 thickness can be used. The success rate of skin grafting can be improved if the wound is thoroughly debrided before the graft is placed. Further survival of the skin piece can be achieved if the grafted skin is covered with silicone dressing or petroleum jelly gauze and VAC device is used for 3 days after surgery. The procedure ensures that the skin fragment is in close contact with the wound base and that the fluid accumulation between them is removed (Figure 6).
For terminal ulcers of the lower extremity, the Unna boot dressing allows immediate postoperative mobility of the patient. If the ulcer is located near a joint or on a muscular tendon, a splint or external fixation brace may be used for more than 2 weeks to ensure graft viability. If the graft is located on the plantar aspect of the foot, the patient needs to be kept in a non-weight bearing position until the skin fragment is viable, which may take up to 6 weeks.
For plantar wounds, the ideal skin fragment is a graft from the arch of the foot, maintained to a thickness of 0.030, which allows for the formation of normal plantar skin. In contrast, the donor area can be healed in 2 stages or with a thinner autologous flap graft. Plantar graft flaps take longer to heal, which requires the affected limb to be weight-free until the skin fragment is fully viable.
Figure 5 Preparation of the affected limb for transmetatarsal osteotomy A Thorough debridement B Removal of the metatarsal head to form a new metatarsal arc C The fifth toe is filleted and the wound is flushed with saline in a pulsatile fashion, using all available tissue to close the wound
Figure 6 This patient has gangrene of the toe and metatarsal headA When the wound is clean, the metatarsal can be shortened posteriorly by 1 cm using a parabolic shape of the softer tissue envelope.B The skin margins are pulled close to each other and a graft is placed over the exposed wound, ensuring its fixation for 3 to 5 days, while the use of a VAC device ensures maximum adsorption.C Complete wound healing takes approximately 6 weeks.
Local Soft Tissue Flap
Local tissue flaps are tissues that cannot be identified as having a blood supply in the immediate vicinity of the defect. Any shape can be used (square, rectangular, diamond, semicircular, lobulated) usually containing skin, fat or skin, fat, and fascia. The aspect ratio is very critical for the survival of the flap endings. This is because skin vessels are not as well organized as muscle. The aspect ratio should not exceed 1:1 or 1:1.5, which will increase the viability of the flap. If possible, arterial flow signals can be measured at the flap tip using Doppler.
Local flaps are very useful in the management of smaller defects. The donor area can usually be treated with one-stage sutures or skin grafts. To increase the size of the flap, delayed dissection of the flap is required for 4 to 10 days. The simplest method is to cut and peel along both sides of the flap. The incision is sutured and the blood is pushed from the proximal end to the distal end and vice versa. When the flap is sufficiently delayed, the top of the flap is cut and lifted and rotated to the skin defect location.
In the ankle joint, a local transfer flap can be used to cover the exposed bone or joint, and this method is very useful. The remaining defect can be treated with a skin graft. It is usually safe to perform blood flow testing of the tip of the transfer flap using Doppler.
Tip flap
Preoperatively, it should be determined that the tip of the tilted flap has an artery passing through it. These flaps can be dermal, fascial, myocutaneous, myocutaneous, osteocutaneous, and osteomyocutaneous flaps. If these flaps are not initially traumatized, infected, or irradiated, they will survive well. Otherwise, there may be stiffness, anatomic difficulties, and torsional difficulties. In addition, the vascular tolerance of the tip is at its worst when the tip flap is twisted to cover the defect area. The incidence of complications is as high as 40%.
Microsurgical free flaps
The microsurgical free flap is the most complex of the reconstructive procedures, but has the highest success rate (95%). The recipient area should have arteries and veins corresponding to the microsurgical free flap. Muscle flaps with or without skin can be used to cover osteomyelitis or foot defects. Good muscle flap donor areas include the thin femoral, serratus, and latissimus dorsi muscles. Fascial flaps and skin flaps survive well in nonweight-bearing areas (dorsal aspect of the ankle and foot). Fascial flaps mostly originate from the radial aspect of the forearm, lateral aspect of the arm, lateral aspect of the thigh, and around the scapula.
Treatment options
The treatment plan for the diabetic foot must follow the lines described above, with careful evaluation of the wound blood supply, the presence of abnormal biomechanics, the size and depth of the wound, and the presence of infection, as well as an assessment of the patient’s medications. If wet gangrene is present, debridement should be performed immediately with the patient’s consent. If the wound is stable, all protocols for managing the wound should be initiated, optimizing the medication and vascular status and repeated debridement. If the skeletal structure is unstable, external fixation may be applied appropriately.
VAC devices, hyperbaric oxygen therapy, growth factors, and vascular flap grafts are all available tools if the wound does not turn out to be healthy. After debridement and VAC device, most wounds improve.
When the wound turns healthy, reconstructive surgery can be used to cover the tissue defect. The simplest reconstructive approach should be used along with improving the biomechanics of the foot. 90% of wounds achieve healing with the use of 2-stage healing, delayed one-stage healing, skin grafts, and local flaps. It is important to be aware of and address abnormal biological stresses that recur, such as the frequent clinical over-tightening of the Achilles tendon, which can lead to ulceration or ulcer recurrence. The dressings used should be carefully selected postoperatively to avoid bacterial invasion of the open wound area. Weight-free loading of the affected limb has been included as a rule of treatment. Patients should keep the limb free of weight for several weeks until the wound heals. Alternatively, a suitable brace or shoe may be used and the patient may be allowed to move at this time.
Management of Complications
Complications of foot and ankle reconstruction occur in 30-40% of diabetic patients and include wound dehiscence, infection, and loss of skin grafts. The main complication is wound dehiscence (20%). This is mainly caused by poor fixation or poor blood flow, while no complications occur in patients who are weight-free. In contrast, in patients with frequent use of removable ambulatory supports, the complication rate is 28%, and postoperative dressing use and weight-free methods are key to reducing complications. Reconstructive surgery in non-vascular areas can also lead to incisional dehiscence due to poor local blood flow, which often occurs in diabetic patients with renal failure. The vascular surgeon should re-evaluate the patient for the next step of revascularization. If worse, a proximal amputation may be considered. If there is no blood leakage from the wound edges, amputation of the entire lower extremity may be required.
Infection is the 2nd most frequent complication after diabetic reconstructive surgery. Therefore, the first debridement and reconstructive surgery cannot be performed until the wound is clean and no infection is present. Instead, reconstructive surgery should be performed at stage 2 or other, when the wound is free of inflammatory reaction and shows signs of healing. To reach this stage, wound healing measures such as VAC devices, growth factors, hyperbaric oxygen therapy, and cultured skin substitutes may be required. Patients with diabetes mellitus with renal failure are prone to tissue margin necrosis early in the wound presentation due to residual underlying infection. Treatment is determined debridement and delayed phase I closure.
Skin graft failure is also a complication and occurs with residual infection, poor blood flow to the wound base, presence of shear stress at the graft site, poor union with the wound, or the presence of a hematoma. The infection rate can be reduced by debridement to form a sufficiently healthy granular wound and the use of silver ionomer dressings, silver sulfadiazine, VAC devices, and temporary allografts.
The incidence of hematoma or seroma is reduced by mesh skin grafting. The use of VAC devices on skin grafts for 3 to 5 days postoperatively allows good adherence of the graft to the wound and reduces the risk of local shear stress. In addition the VAC device removes exudate from the trauma and keeps the bacterial inoculum of the trauma at subclinical levels. The use of petroleum jelly and dimethicone gauze between the graft and the sponge allows for easy removal of the device. Foot protection and braking is applied until graft viability (3-6 weeks).