Skin Grafts
Fat Grafts or Not
Other Grafts
Flaps I
Flaps II
100
A 27-year-old man is scheduled to undergo excision and skin grafting after sustaining a full-thickness burn to the dorsum of the hand. To optimize graft take in this patient, which of the following is the most important aspect of management? A ) Meshing of the skin graft B ) Meticulous hemostasis C ) Negative pressure wound therapy D ) Use of fibrin glue E ) Use of a thin split-thickness skin graft
What is B The most important aspect of recipient site management to optimize graft survival and outcome in this patient undergoing dorsal hand skin grafting is meticulous hemostasis. This is because hematoma is the leading cause of skin graft loss. Meshing a skin graft may promote graft survival by providing a mode of egress for blood and seroma that might form below the graft. However, it is associated with an increased rate of secondary contraction and unfavorable cosmetic results. Both of these factors make meshing undesirable when grafting the dorsum of the hand. Use of a negative pressure wound therapy dressing can result in improved graft survival, especially in recipient sites with irregular contours. However, it is not critical for the hand. A good dressing and proper immobilization should achieve the same result. Use of this type of dressing is not as important as meticulous hemostasis for ensuring graft survival and outcome. Fibrin glue has been used to promote graft survival by improving hemostasis and graft adherence. There is also some evidence that fibrin glue may inhibit wound contraction. Nevertheless, it is no substitute for meticulous hemostasis and should only be used as an adjunct to the fundamental techniques of skin graft placement. Use of a thin split-thickness skin graft is associated with improved graft survival when compared with a thick split-thickness or full-thickness skin graft, but it is also associated with an increased rate of secondary contraction that is not desirable on the dorsum of the hand. Balancing the need for graft survival versus the need to avoid secondary contraction is an important consideration in burn surgery. Using thinner grafts will optimize graft survival, but this is not as critical as ensuring good hemostasis.
100
A 42-year-old woman with a history of progressive facial atrophy comes to the office because of a moderately sized soft-tissue deficit on the left side of the face. She is scheduled to undergo a single fat transfer procedure for correction. Which of the following is the most likely outcome of this procedure in this patient? A ) Donor site seroma B ) Facial nerve injury C ) Fat embolism D ) Hypertrophic scarring E ) Inadequate correction
What is E Romberg disease, or progressive facial atrophy, is a rare pathologic process characterized by an acquired, idiopathic, self-limited, unilateral atrophy of the face, variably involving skin, subcutaneous tissues, fat, muscle, and less frequently, the underlying bone structures. Methods of restoration of facial contour and volume in these patients include synthetic implants, bone grafts, free tissue transfer, and fat grafting. Fat injections have been used for over 20 years to correct soft-tissue deformities throughout the body. Fat grafts are often used for ?touch-up? of various reconstructive procedures. This technique has been found to be helpful as an adjunct to free tissue transfer in cases of progressive facial atrophy and congenital hemifacial microsomia. Although fat embolism has been rarely reported during fat transfer in the face, complication rates of fat grafting are low, especially when compared with complications of free tissue transfer for reconstruction of facial deformities, which may include donor site seroma, facial nerve injury, and hypertrophic scarring. The most common adverse outcome of fat grafting is likely to be inadequate correction with a single-stage procedure. A recent study found that no statistically significant difference was found in satisfaction rates between free flap reconstruction and serial fat grafting of soft-tissue deficits in hemifacial microsomia.
100

A 9-year-old girl with a unilateral cleft lip and palate undergoes alveolar bone grafting with a cancellous iliac graft. Which of the following is the most likely mechanism by which the bone graft will heal in this patient? A ) Endochondral ossification B ) Osteoconduction C ) Osteogenesis D ) Osteoinduction E ) Progenitor cell recruitment

What is C The most likely mechanism of cancellous bone graft healing is by osteogenesis. Cancellous and vascularized bone grafts heal primarily by osteogenesis. Because these grafts are rapidly revascularized, osteoblasts survive the transplantation and produce new bone at the recipient site. Endochondral ossification is the embryologic process by which bones of the appendicular skeleton, vertebral column, and skull base are formed. The maxilla develops by membranous ossification. Osteoconduction, or "creeping substitution," is the mechanism by which cortical bone grafts heal (e.g., split cranial bone graft). After cortical bone is separated from its blood supply, it serves as a nonviable scaffold for the ingrowth of blood vessels and osteoprogenitor cells from the recipient site. This leads to resorption and replacement of most of the graft with new bone. The graft becomes fully osseointegrated with the recipient site. Osteoinduction involves the stimulation of mesenchymal cells at the recipient site to differentiate into bone-producing cells. Demineralized bone and bone-morphogenic protein produce new bone by osteoinduction. Although progenitor cells might be recruited to an area where bone grafting has occurred, they are not a primary mechanism for cancellous bone graft healing.

100
A 55-year-old woman is scheduled to undergo surgery for soft-tissue coverage of an open joint elbow wound. The vascular pedicle of the flap in the photograph shown (radial FF) passes between which of the following tendons? A) Brachioradialis and abductor pollicis longus B) Brachioradialis and flexor carpi radialis C) Brachioradialis and flexor pollicis longus D) Brachioradialis and pronator teres E) Flexor carpi radialis and pronator teres
What is B The vascular pedicle of the radial forearm flap is the radial artery that is a branch of the brachial artery. Proximally, the radial artery runs deep to the brachioradialis muscle and it passes distally between the bellies of the brachioradialis and flexor carpi radialis. The radial forearm flap cutaneous paddle is perfused by septocutaneous perforators from the radial artery. The other options are incorrect because the vascular pedicle does not pass between those muscles.
100
A 28-year-old man is evaluated in the emergency department because of a soft-tissue defect of the dorsum of the hand with exposed extensor tendons. Reconstruction is planned with a fasciocutaneous free flap that is centered on the axis between the anterior superior iliac spine and patella. Which of the following arteries is the most likely pedicle of this flap? A ) Ascending branch of lateral femoral circumflex B ) Ascending branch of medial femoral circumflex C ) Descending branch of lateral femoral circumflex D ) Descending branch of medial femoral circumflex E ) Superficial femoral
What is C The pedicle to the anterolateral thigh flap is the descending branch of the lateral femoral circumflex artery. The anterolateral thigh flap is a fasciocutaneous flap that has gained in popularity. This flap is capable of providing pliable tissue with a fascia to allow for tendon gliding. The flap has a large skin territory and does not require the sacrifice of a major vessel. The flap is based on perforators from the descending branch of the lateral femoral circumflex artery, which arises from the profunda femoris artery. The artery travels between the vastus lateralis and rectus femoris muscles and may travel in the septum or within the substance of the muscles. The flap is centered on the axis between the anterior superior iliac spine and the superior lateral border of the patella. Perforators to the anterolateral thigh flap can be variable, but the majority lies within 3 cm of a circle centered along the midpoint of that line. The ascending branch of the lateral femoral circumflex artery forms the pedicle for the tensor fascia lata flap. The ascending branch of the medial femoral circumflex artery forms the pedicle for the gracilis muscle flap. The descending branch of the medial femoral circumflex artery supplies the adductor muscles.
200
A 33-year-old man who sustained burns to 95% of the total body surface area five days ago is scheduled to undergo the initial stages of surgical reconstruction. In preparing this patient, which of the following is the advantage of using cultured epidermal autografts versus split-thickness skin grafts? A ) Donor site B ) Durability C ) Elasticity D ) Immediate availability E ) Reduced expense
What is A With use of cultured epidermal autografts, no donor site limitations exist. The patient €™s own keratinocytes are expanded in tissue culture and a small skin specimen may be cultured and expanded within two to three weeks. Unfortunately, there is no dermal matrix tissue and, therefore, the graft lacks the elastic quality of normal skin or even split-thickness skin grafts. This results in wounds that are stiff, and motion is limited in the face and around joints. Likewise, the lack of a dermis results in very slow basement membrane formation; therefore, there are frequent problems with blistering and easy shearing. The use of cultured epidermal autografts is somewhat limited by its high cost and delay in availability as the tissue is cultured.
200
A 63-year-old woman is scheduled to undergo autologous fat injection to improve the contour and increase the size of the right breast. She underwent reconstruction of the right breast with a latissimus dorsi flap 10 months ago because of mastectomy. The patient does not have or desire a breast prosthesis. Which of the following is the most likely sequela of autologous fat injection in this patient? A) Calcification B) Donor site irregularity C) Fat resorption D) Hypertrophic scarring E) Skin necrosis
What is C Although controversial, autologous fat injection (lipo-modeling) to the breast and the reconstructed breast has gained popularity in recent years. This can be attributed to several factors, including the publication of large numbers of patient series' demonstrating the safety, efficacy, and improvements in the harvest and preparation of fat. However, the most common complication of fat injection remains to be the resorption of the grafted fat, ranging from 30 to 70%. Fat and skin necrosis, calcification, hypertrophic scarring, and contour irregularity of both the recipient and donor sites can occur, but to a lesser extent. The rate of skin necrosis is low. Hypertrophic scarring is more common in patients with a history of poor scarring. In the case of calcifications, pre- and postoperative examination by a radiologist specialized in breast imaging is necessary to limit the risk of breast cancer, which may occur coincidentally with lipo-modeling.
200

A 34-year-old man undergoes correction of the defect shown three years after sustaining an injury to the left tip of the nose while playing football. Placement of an alar batten graft is planned. During septal graft harvest, the mucoperichondrial plane is difficult to elevate, and the cartilage is removed with an adherent perichondrial layer. Which of the following is most likely to result from the use of this graft compared with a cartilage-only graft? A ) Extrusion B ) Necrosis C ) Ossification D ) Resorption E ) Warping

What is E Pure cartilage grafts tend to maintain shape, but grafts with an intact perichondrial layer can curl significantly and lead to unpredictable results. During septal graft harvest, care must be taken to elevate mucoperichondrial flaps in the proper plane. Likewise, auricular or costal cartilage grafts must be harvested in a subperichondrial plane. Removal of the perichondrium and softer outer cartilage layer leaves the more rigid cartilage core, which maintains shape more predictably. Extrusion, necrosis, ossification, and resorption are not known to be affected by the presence or absence of the perichondrial layer. The alar batten graft is a useful means of adding support to a deformed or weakened alar cartilage Warped cartilage has a €œmemory € and tends to return to its warped shape unless adequate support is provided.

200
A 48-year-old man has infected hardware 4 weeks after undergoing spinal fusion. The neurosurgeon washes out the wound and requests consultation for coverage of the defect. In the operating room, the plastic surgeon notes that coverage with a paraspinous muscle flap is not possible, as the muscle has been heavily debrided by the neurosurgeon. Use of a reverse latissimus dorsi flap is planned. These two flaps share an arterial blood supply from which of the following arteries? A) Circumflex scapular B) Posterior intercostal C) Superior gluteal D) Thoracodorsal E) Transverse cervical
What is B The paraspinous muscle is supplied by the posterior intercostal artery; this is the same vessel that supplies the reverse latissimus dorsi flap. For a midline spinal defect, it is unlikely that these vessels are damaged; however, this is possible in large oncologic resections or traumatic injuries. The circumflex scapular artery supplies multiple flaps that are used for reconstruction, including the scapular and parascapular flaps. The transverse cervical artery supplies the trapezius muscle flap. The superior gluteal artery supplies the gluteus maximus muscle. The thoracodorsal artery is the main arterial supply of the latissimus muscle.
200
A 24-year-old man is brought to the emergency department after sustaining a degloving injury of the long, ring, and little fingers of the dorsal, nondominant left hand in a high-speed, rollover motor vehicle collision. Following debridement, the patient has obvious open proximal interphalangeal (PIP) joints of each of these fingers. Which of the following is the most appropriate management of these defects? A ) Cross-finger flap coverage B ) Full-thickness skin grafting from the groin C ) Pedicle lateral arm flap coverage D ) Reverse radial forearm flap coverage E ) Split-thickness skin grafting from the thigh
What is D Pedicled fascial flaps to the hand provide an excellent reconstructive option in cases of exposed tendon, joint, or bone where soft-tissue coverage is needed. They provide thin, broad, well-vascularized coverage and a gliding surface for tendons and joints. The pedicled reverse radial forearm flap is the most appropriate option for this defect. The cross-finger flap may be an option for a single digit, but not in the large zone-of-injury described. The groin flap, although reliable, is bulky and requires the attachment of the upper extremity to the trunk, followed by division and insetting of the flap at a later time. The pedicle lateral arm flap cannot reach the fingers. The reverse radial forearm flap may be harvested with skin or simply as a fascial flap. Skin grafting, either full- or split-thickness, would not be appropriate coverage for exposed joint surfaces.
300
After harvesting of a split-thickness skin graft from the lateral aspect of the thigh, application of which of the following types of wound care agents will yield the most rapid epithelialization at the donor site? (A) Normal saline wet-to-dry gauze (B) Occlusive dressing (C) Petrolatum-impregnated gauze (D) Semi-occlusive dressing (E) Silver sulfadiazine cream
What is D The ideal donor site dressing is one that promotes rapid re €‘epithelialization, causes little pain, requires little care, is inexpensive, and has a low rate of infection. Options include occlusive dressings (Duoderm), semi €‘occlusive dressings (OpSite, Tegaderm), semi €‘open dressings (petrolatum-impregnated gauze, Xeroform or scarlet red), and no dressing. Although semi €‘open techniques using a heat lamp to dry the donor site covered with Xeroform or scarlet red are historically popular, these dressings do not meet current concepts of promoting wound healing by providing a moist environment. In multiple studies, the superior dressings have been shown to be semi €‘occlusive. These products have been shown to have the fastest healing rates (average nine days to re €‘epithelialization), lowest subjective pain scores, lowest infection rates (~3%), and are among the lowest in cost. They have the advantage of being transparent, which allows ongoing inspection of the site while maintaining sterility. Some fluid collects under these materials, which promotes moist wound healing and probably accounts for the more rapid healing rates and decreased subjective pain scores. Donor sites for split €‘thickness skin grafts heal spontaneously from epithelial cells remaining in epithelial appendages within the dermis and at the wound edges. Healing begins within 24 hours of harvesting, and the rate of healing is directly proportional to the number of epithelial appendages remaining and inversely proportional to the thickness of graft harvested. When the epidermis has regenerated it may be reharvested; however, each harvesting removes a portion of dermis that is not regenerated. The initial epithelium that is regenerated is very delicate and easy to disrupt with tape or dressing changes. This is another reason to use the semi €‘occlusive dressing technique that does not need to be removed until healing is complete.
300
A 51-year-old woman has loss of vision in her left eye immediately after autogenous fat injections to the face and nasojugal regions performed under local anesthesia with 2 mL of 1% lidocaine with 1:100,000 epinephrine. The procedure was performed using small boluses of fat, which were injected slowly into the tear trough. Physical examination shows loss of vision in the left eye. Which of the following occurrences is the most likely cause of this complication? A ) Fat embolism B ) Glaucoma C ) Lidocaine toxicity D ) Retrobulbar hematoma E ) Vasovagal response
What is A Blindness and strokes have occurred as a result of the injection of soft-tissue fillers in almost every part of the face: glabella, forehead creases, temple, nose, cheeks, nasolabial folds, and lower lip. The injection of large boluses of soft-tissue fillers in the face and the use of needles or cannulas that can easily perforate an arterial wall should be avoided. Fat injections into the face lead to an acute local increase in pressure in highly vascularized tissue. Fragments of fatty tissue reach ocular and cerebral arteries by reversed flow through branches of the carotid arteries after they are introduced into facial vessels. The manifestation of fat embolism appears either immediately after the fat injection or after a latency period. To minimize the risk of such a major complication, fat injections should be performed slowly, with the lowest possible force. Fat injections into pretraumatized soft tissue, for example, after rhytidectomy, should be avoided because of the increased risk of intravasation of fat particles.
300
A 27-year-old woman is scheduled to undergo rhinoplasty using homograft rib cartilage for reconstruction of the dorsum of the nose. Which of the following interventions during this procedure is most effective to reduce long €‘term warping of the graft? (A) Access to a peripheral segment (B) Insertion of the graft at least 30 minutes after carving (C) Scoring of the graft (D) Suture fixation (E) Use of nonirradiated material
What is B To minimize the long €‘term clinical effects of cartilage warping, it is recommended to wait at least 30 minutes after carving the graft to allow initial warping to occur. The observed warping can then be accounted for in the final graft placement. Further warping may continue for some time, but the majority will occur within the first 30 to 60 minutes. Use of nonirradiated graft material may predispose more warping than irradiated material; however, this may depend on the dose of radiation. Doses of 3 to 4 million rads are less likely to result in graft warping compared with no radiation, but at doses of 1.5 to 2.5 million rads, the warping may be similar to that of nonirradiated grafts. Central cuts of cartilage grafts are less likely to warp than are peripheral cuts. Scoring of the graft will result in warping of the graft. Suture fixation will not prevent graft warping.
300
A 52-year-old man is brought to the emergency department after sustaining injuries in a motor vehicle collision. Physical examination shows a traumatic degloving injury to the dorsum of the right hand with exposed, intact extensor tendons. Reconstruction with a fascial free flap and full-thickness skin grafting are planned. Which of the following arteries supplies blood to the most appropriate choice of flap? A) Posterior auricular B) Superficial temporal C) Superior thyroid D) Supratrochlear E) Transverse facial
What is B The temporoparietal fascial flap is supplied by the superficial temporal artery. This thin fascial free flap is useful in reconstruction of traumatic injuries that are not amenable to reconstruction with a skin graft alone. This flap is particularly useful in reconstruction of gliding surfaces with denuded tendons or exposed joints. The posterior auricular artery is a branch of the external carotid artery and supplies the posterior ear. The superior thyroid artery arises from the external carotid artery and supplies the thyroid gland. The supratrochlear artery supplies the forehead and scalp. The transverse facial artery is a branch of the superficial temporal artery and supplies the parotid gland. None of these vessels is involved in the vascular supply of the temporoparietal fascial flap.
300
A 55-year-old man is scheduled to undergo a large oncologic extirpation in the groin. Closure of the resulting defect with a rectus femoris musculocutaneous flap is planned. Which of the following is the most likely functional outcome? A) 15-Degree extensor lag of the knee B) 20-Degree flexion contracture of the hip C) Compromised ability to stand for extended periods D) Inability to adduct the leg E) No loss of function
What is A The rectus femoris flap provides reliable and robust soft tissue for coverage of abdominal, groin, and hip defects. Because the rectus femoris is one of the quadriceps muscles and inserts into the patella, its use can have functional consequences. It is generally recommended to perform patellar tendon repair following harvest of the rectus femoris; despite this repair, there can still be about 15 degrees of extensor lag at the knee. Flexion contracture of the hip, difficulty standing for extended periods, and difficulty adducting the leg have not been described with this flap harvest. The expanded rectus femoris flap has several advantages for massive abdominal wall reconstruction. The expanded flap easily can reach the xiphoid, and it has impressive width. The donor site can be closed primarily with an acceptable scar. The muscle remains innervated and functional, which may help prevent bulging. Large or complicated abdominal wall defects caused by recurrent incisional hernias, infections, or tumor resections often require the use of prosthetic mesh, local tissue transposition, or even distant muscle flaps for proper reconstruction. In a series of 12 cases of reconstruction of the abdominal wall using pedicled rectus femoris muscle flaps for wounds resulting after tumor resections, recurrent incisional hernias, and infection, abdominal wall stability and donor site morbidity were examined clinically. Follow-up time ranged from 6 months to 4 years. In all but one patient, a stable abdominal wall could be reconstructed. The loss of true muscular capacity in the quadriceps muscle of the operated leg was 19% compared with the nonoperated leg, but this result was tolerated well.
400
A 30-year-old man undergoes reconstruction of the right lower leg after sustaining an open fracture of the tibia. A skin graft is harvested and placed over a free muscle flap. Two days postoperatively, which of the following findings on microscopic examination of the skin graft is most likely? (A) Early ischemic injury (B) Increased collagen cross €‘linking (C) Neovascular circulation (D) Significant edema (E) Venous congestion
What is D Within the first 24 hours after placement, the graft survives by serum imbibition, which is absorption of nutrients from the serum leaked from the donor site (muscle in this case). At 24 hours, the healing graft will have increased in mass from edema by up to 30%. Leukocytes can be seen invading the graft, which may help stimulate endothelial migration and revascularization. By 24 hours, donor site vessels have begun to invade the graft vascular channels in a process called inosculation. The graft vessels degenerate and become replaced by the growing donor site vessels. Circulation is reestablished by day 4 to 5 at the earliest. Whereas early graft ischemia results in a lowering of the pH and a decrease in metabolism, ischemic injury and necrosis are not seen. Graft maturation and collagen turnover occur over weeks to months. Early recognition and correction of the venous thrombosis are not likely to affect early graft nourishment and healing.
400
A 26-year-old woman of Asian descent who underwent rhinoplasty five years ago has erosion of the silicone rubber (Silastic) prosthesis through the skin of the nasal tip. Physical examination shows a depressed scar in this region. Secondary rhinoplasty is planned. Use of which of the following grafts for this procedure is most appropriate to minimize volume loss? (A) Dermis (B) Fat (C) Muscle (D) Cartilage (E) Bone
What is D A cartilaginous graft would be most appropriate to correct the deformity described. The low metabolic rate of cartilage leads to minimal volume loss. Fat graft survival depends on early neovascularization and only approximately 50% of lipocytes in an autogenous graft survive. Owing to the traumatic nature of the suction technique, fewer viable micrografts are transferred with potential for survival so that surgically removed grafts (macrografts) have a greater longevity. Animal studies have also demonstrated that adipocytes implanted in a vascularized bed (muscle) survive better than those in dermis. Considerable resorption is seen in nonvascularized bone grafts. Muscle alone is not routinely transferred as a graft. There are not sufficient studies in the literature to support the routine use of dermis to correct this deformity.
400
Compared with cortical bone, which of the following best characterizes autologous cancellous bone grafts? (A) Effective in bridging defects larger than 6 cm (B) Greater structural strength (C) Less osteoconductive (D) Less osteoinductive (E) More readily revascularized and remodeled
What is E Relative to cortical bone, cancellous bone grafts are more osteoconductive (the property of the scaffold €‘like matrix to accommodate the ingrowth of new bone) and more osteoinductive (the capacity to induce mesenchymal cells from the recipient bed to produce active osteoblasts). Cancellous bone is more quickly revascularized, which usually occurs within two weeks of grafting, whereas cortical bone can take up to two months to revascularize. Cancellous grafts are also more easily remodeled. Cancellous bone grafts are ideal for bridging bone gaps of less than 5 to 6 cm, but suffer from a lack of structural rigidity until 6 to 12 months after grafting, when they are generally as strong as cortical bone grafts.
400
A 28-year-old man is brought to the emergency department after sustaining a dog bite to the face. Physical examination shows subtotal loss of the nose and glabella. Staged reconstruction with a forearm flap is performed, with initial elevation of the flap, placement of cartilage grafts, and creation of nostrils. Thinning and refinement are performed during a second procedure with additional cartilage grafting. The flap is microsurgically transferred to reconstruct the nose in a third procedure. Which of the following is the most appropriate description of this flap? A) Delayed B) Freestyle C) Prefabricated D) Prelaminated E) Tubularized
What is D The flap described in this scenario is a prelaminated flap. A prelaminated flap is an axial flap that is modified with the addition of various grafts (e.g., skin, mucosa, cartilage, bone), re-creating the missing tissues at the donor site prior to flap transfer. A delayed flap is one that undergoes one or more vascular insults prior to final flap elevation to induce increased circulation and maximize flap perfusion. A freestyle flap is a nonaxial flap harvested by locating a cutaneous Doppler signal in a chosen donor site, identifying the vessels supplying that tissue, and dissecting them down to a pedicle of sufficient length and/or diameter. The anatomy is not known ahead of time, and thus harvest is performed ?freestyle.? A prefabricated flap is created by transferring a vascular pedicle into an area of tissue that is ideal for transfer to induce angiogenesis from the pedicle into that tissue, which can then be harvested for transfer. A tubularized flap is one that is sewn to itself to create a tube or passive conduit, such as an anterolateral thigh flap used for pharyngoesophageal reconstruction.
400
A 70-year-old woman has a circular defect 18 cm in diameter on the parietal aspect of the scalp after excision of squamous cell carcinoma. The pericranium has been removed with the scalp tissue. Adjuvant radiation therapy is planned beginning 4 to 6 weeks after surgery. Which of the following is most appropriate for coverage of the defect? A) Latissimus dorsi muscle free flap with split-thickness skin graft B) Primary closure after galeal scoring C) Split-thickness skin grafting D) Temporary reconstruction with a split-thickness skin graft followed by a rotation-advancement flap after scalp tissue expansion
What is A The latissimus dorsi muscle free flap with split-thickness skin grafting can be used to reconstruct large scalp defects in a single stage, allowing the patient to proceed with radiation therapy after recovery from surgery. While temporary reconstruction with a split-thickness skin graft followed by definitive reconstruction with a rotation-advancement flap after tissue expansion is feasible for defects approaching 50% of the scalp surface area, this choice is inappropriate, as skin grafts usually have poor take on bare calvarium devoid of pericranium, particularly when treated with radiation. Radiated tissues are more difficult to expand, and their expansion is associated with a high rate of complications. Primary closure is usually only feasible in scalp defects less than 3 cm in diameter, even with galeal scoring to increase scalp flap length and reduce wound tension. Graft take can be improved by burring the bone down to the bleeding diploic space, but this technique results in unstable bone coverage, particularly in the setting of postoperative radiation.
500
Which of the following is the best donor site for delayed multiple harvesting of split-thickness skin grafts? (A) Back (B) Lateral forearm (C) Medial arm (D) Medial forearm (E) Medial thigh
What is A The selection of a donor site depends largely on donor site morbidity and skin thickness. The back provides a nearly ideal donor site for repeated harvesting of split-thickness skin grafts and has large areas of thick skin available for harvesting. The lateral forearm exhibits unacceptable donor site morbidity. The medial arm, medial forearm, and medial thigh have skin of insufficient thickness to allow multiple harvesting. The number of times that a donor site can be harvested for split-thickness skin grafts is limited by the thickness of the dermis at the site. A split-thickness skin graft includes the epidermis and part of the dermis. The donor site of a split-thickness graft heals by migration from the remnant epithelia of the dermal appendages, such as hair roots and sweat and sebaceous glands. Therefore, the epidermis regenerates but the dermis does not. A repeat split-thickness graft may be harvested once the skin has reepithelialized, but a thinner dermis will remain at the donor site.
500
Injection of autologous fat at which of the following sites is associated with increased risk for fat embolism and subsequent blindness and/or central nervous system damage? (A) Forehead (B) Glabella (C) Lateral orbit (D) Nasolabial fold (E) Tear trough
What is B Although injection of autologous fat during aesthetic and reconstructive procedures is typically a safe procedure, adverse effects, such as fat embolism and central nervous system damage, have been reported. The surgeon should be particularly cautious when injecting fat into the glabellar region, as the ophthalmic artery, which connects directly to the glabellar vasculature, can be inadvertently divided. Methods to help minimize complications of fat injection include the use of blunt tip large bore cannulas, as well as retrograde injection techniques. Although the risk for injury exists with injection into the periorbital and nasal regions, it is less than that seen with injection into the glabellar region. Injection into the region of the frontalis muscle (ie, forehead), or into crow's feet in the region of the lateral orbit, a tear trough, or the nasolabial fold is associated with a lower risk for fat embolism than injection into the glabellar region.
500
Which of the following bone grafts exhibits the greatest inductive capacity? (A) Allogenic (B) Autologous cancellous (C) Autologous cortical (D) Free vascularized (E) Xenogenic
What is B Cancellous bone grafts have the greatest inductive capacity (ability to stimulate the formation of new bone) because they contain bone morphogenic proteins that stimulate bone growth. Cortical bone grafts and allogenic and xenogenic grafts have less inductive capacity. Free vascularized bone grafts have no inductive capacity because they do not rely on stimulating new bone formation.
500
An 18-year-old man undergoes open reduction with tension band wiring to treat a fracture of the olecranon he sustained in a bicycle collision. Postoperatively, he develops a wound infection, resulting in an open wound over the elbow. Coverage with a posterior interosseous fasciocutaneous flap is planned. Which of the following best describes the anatomical location of the dominant pedicle of this flap? A ) Anterior to the pronator teres and deep to the brachioradialis B ) Between the extensor carpi ulnaris and the extensor digiti minimi C ) Between the flexor digitorum profundus and flexor pollicis longus D ) Deep to the brachioradialis and lateral to the flexor carpi radialis E ) Superficial to the anconeus and extensor digitorum muscle
What is B The posterior interosseous flap is a pedicled forearm flap based off the posterior interosseous artery (PIA) proximally. It can be rotated to cover elbow, antecubital fossa, or proximal volar forearm defects. A reversed version, based off the anterior interosseous arterial connections to the PIA, can be used for wrist and hand defects. The PIA emerges in the proximal dorsal forearm deep to the supinator. It then courses between the extensor carpi ulnaris (ECU) and the extensor digiti minimi (EDM). During dissection of a standard posterior interosseous flap, the pedicle is found distally in the forearm between the ECU and EDM then dissected proximally. The superficial branch of the radial nerve is located anterior to the pronator teres and deep to the brachioradialis. The anterior interosseous artery is found between the muscle bellies of flexor digitorum profundus and the flexor pollicis longus. Distally in the forearm, the radial artery is deep to the brachioradialis and radial to the flexor carpi radialis. Proximally in the forearm, the posterior cutaneous nerve of the forearm is found superficial to both the anconeus and extensor digitorum muscle.
500
A 24-year-old right-hand-dominant male construction worker is evaluated because of a right dorsal thumb abscess that is treated with debridement and administration of antibiotics. A photograph of the residual defect is shown (exposed thumb extensors without paratenon between MCP and IP joints). Which of the following is the most appropriate method for reconstruction in this patient? A ) Coverage with a muscle flap B ) Coverage with a skin flap C ) Full-thickness skin grafting D ) Negative pressure wound therapy E ) Split-thickness skin grafting
What is B The residual defect includes exposed extensor tendon without paratenon. This fact, combined with the need for flexion at the interphalangeal joint and avoidance of contracture, as well as the likely need for future tenolysis, makes a skin flap the most appropriate option for reconstruction. In the scenario described, a first dorsal metacarpal artery pedicled skin flap is used to reconstruct the thumb defect with the need for back grafting of the donor site. This provides the best combination of low donor-site morbidity, the ability to provide stable soft-tissue coverage over exposed tendon without paratenon, and the competitive advantage of being relatively easy to re-elevate for subsequent procedures, if needed. A muscle flap could be used to reconstruct the defect but would not be optimal due to the increased donor site morbidity from muscle sacrifice, as well as the increased difficulty in re-elevation versus a skin flap over tendon. Healing by secondary intention, with or without topical negative pressure wound therapy, will certainly result in extensive contracture as well as an increased time to heal. This will impact the patient’s outcome both in terms of his ability to return to work as a construction worker as well as limitations on his functional range of motion. Skin grafting, whether split- or full-thickness, is not a reliable option in this patient because of the exposed tendon without paratenon. It is important to note that this is a classic contraindication to skin grafting and therefore leads to a flap-based reconstruction. Furthermore, skin grafts would lead to increased contraction versus flaps and would be difficult to re-elevate for subsequent procedures.
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