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11 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Primary contracture of a graft is from X in the dermis, whereas secondary contracture is from Y activity. |
Primary contracture of a graft is from elastin fibers in the dermis, whereas secondary contracture is from myofibroblast activity. |
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Mechanism of bone healing: 1. Cancellous bone graft 2. BMP 3. Cortical bone 4. Free vascularized bone flap |
Osteoinduction refers to the direct stimulation of mesenchymal cells at the recipient site by bone morphogenetic protein to differentiate into osteoprogenitor cells. This mechanism of action is associated with the healing of cancellous bone grafts and demineralized bone matrix.
Osteoconduction (creeping substitution) is the primary method by which cortical bone grafts heal. During osteoconduction, cells and blood vessels from the recipient bed grow into the graft. The bone graft becomes a template for the deposition of new bone and the graft resorbs. Neovascularization is complete by 6 to 8 weeks, but ultimate strength of cortical grafts is not seen until 6 to 12 months, at which time the graft is comparable to a vascularized bone graft.
Osteogenesis is the formation of new bone by cells in a flap/graft that survive the transfer. This is the primary mechanism by which a vascularized bone graft heals. The pedicle keeps the bone alive so that primary bone healing can occur between the graft and recipient site. Osteoblasts from both locations participate in the formation of new bone at the interface between graft and native bone. Advantages of a vascularized bone graft include the ability to place the graft into a hostile environment such as an irradiated wound bed and immediate structural support with shortened time to bony union compared with nonvascularized cortical grafts. * Other question states iliac crest graft has both osteoconductive & osteoinductive properties.
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Best 3 ribs for harvest? Which is safest? |
Ribs five through seven are commonly described as the ideal sites for harvesting because of ease of access and ample bone material compared with the more cephalic or caudal ribs. The seventh rib has the added advantage of being situated over the abdominal cavity, reducing the risk for pneumothorax during harvest. Ribs five and six are also suitable, and may hide better in the inframammary crease of women. |
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A 30-year-old man who works as a laborer comes to the emergency department after sustaining avulsion injuries over the dorsum of the index, long, and ring fingers of his right dominant hand after being caught in a press. The wounds measure 3 × 1 cm each. Physical examination shows exposed extensor tendons from the proximal interphalangeal joint to the dorsal fold. Artificial dermis was placed. Which of the following is the most appropriate method of reconstruction? A) Full-thickness skin graft B) Radial artery free flap C) Reverse radial forearm flap D) Split-thickness skin graft E) No further treatment |
The correct response is Option D.
Split-thickness and full-thickness skin grafting directly over extensor tendons will lead to scarring due to lack of paratenon. Paratenon is necessary for tendon gliding. The use of artificial dermis can allow for tendon gliding. Artificial dermis has been shown to result in favorable aesthetic and functional outcomes. Although a second surgery is required, it results with lower donor site morbidity. Once the dermal template is adherent, it can then be grafted. The correct response is split grafting because the artificial dermis acts as the deep layer. Split-thickness grafts alone would not be useful where padding is required. Split grafts have a higher contracture rate than full grafts. Also, split grafts alone would not be beneficial because of the high potential for adherence. A full-thickness graft with its dermal elements would not be necessary in this case because the artificial skin provides the dermal elements. |
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Which of the following bone substitutes has the capacity for osteoconduction and osseointegration? A) Hydroxyapatite B) Polymethylmethacrylate C) Porous polyethylene D) Silicone E) Titanium
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The correct response is Option A. Hydroxyapatite is a bone substitute that has capacity for both osteoconduction and osseointegration and is the base for many of most widely used bone substitutes. Hydroxyapatite is the principal mineral component of bone and comprises 60% of the calcified human skeleton. It has been used clinically for more than 25 years. It is biocompatible, and all forms are resistant to absorption after implantation. |
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Name the dressing: FDA approved for diabetic foot wounds, bilayered constructs of bovine collagen with human keratinocytes and fibroblasts, viable cells in the construct release and stimulate growth factors and matrix proteins to encourage wound healing. |
Apligraf® (Organogenesis, Inc., Canton, MA) and OrCel® (Ortec International, New York) are bilayered constructs of bovine collagen with human keratinocytes and fibroblasts. Although it appears like normal skin, it does not take like a skin graft, but rather the viable cells in the construct release and stimulate growth factors and matrix proteins to encourage wound healing. |
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X-graft comes from a genetically identical donor, namely an identical twin. |
Isograft comes from a genetically identical donor, namely an identical twin. |
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At what age can calvarial bone be split for grafting? |
Calvarial bone is difficult to split until a diploic space has formed, usually after 4 years of age, and some authors do not recommend in situ harvest before 9 years of age. Cranial particulate bone grafting, however, can be harvested at any age, and studies have demonstrated that it is as effective as split calvarial bone graft for closure of cranial defects. |
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Bone grafts & their biologic properties. Which 3 properties does cancellous allograft like iliac crest have? |
Back (Definition) |
This is confusing because there are different answers on different questions... |
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Which of the skin appendages are the primary source of multipotent stem cells responsible for reepithelialization of STSG donor site? |
Hair follicles |
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An 18-year-old woman with a history of cleft lip and palate presents for secondary alveolar bone grafting. An iliac crest bone graft is planned. Which of the following characteristics of iliac crest bone graft is an advantage over the use of bone morphogenetic protein in this patient? A) Greater volume of graft material B) Osteoconductive properties C) Osteoinductive properties D) Reduced operative time E) Reduced recovery time |
B) Osteoconductive properties |
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