In-Service Exam
Wound Healing Keloids - 2003





Which of the following is the ratio of type I collagen to type III collagen in hypertrophic or immature scars?

(A) 1:4
(B) 1:2
(C) 2:1
(D) 4:1

The correct response is Option C.

Patients with hypertrophic or immature scars have a type I to type III collagen ratio of approximately 2:1 in the healing wound. In contrast, the type I to type III ratio in normal skin is 4:1.

Type I collagen is present in greater than 90% of the body's tissues, including bone, tendon, and skin. Type II collagen is predominant in hyaline cartilage and eye tissues. The skin, arteries, uterus, and intestinal wall contain type III collagen, and most fetal wound collagen is type III. Basement membrane is made up predominantly of collagen types IV and V.

References
1. Bailey AJ, Bazin S, Sims TJ, et al. Characterization of the collagen of human hypertrophic and normal scars. Biochem Biophys Acta. 1975;405:412.
2. Glat PM, Longaker MT. Wound healing. In: Aston SJ, Beasley RW, Thorne CH, eds. Grabb & Smith's Plastic Surgery. 5th ed. Philadelphia, Pa: Lippincott-Raven; 1997:3-12.

Deep mechanical massage has been shown to result in which of the following?

(A) Accumulation of collagen bands
(B) Accumulation of mast cell aggregates
(C) Retention of adipocyte cell architecture
(D) Thickening of the epidermis

The correct response is Option A.

Deep mechanical massage, using therapeutic massage units (ie, Endermologie), can be performed for reduction or correction of moderate amounts of cellulite and is often used postoperatively in patients who have undergone body contouring procedures. According to the results of an experimental animal study, there is an accumulation of dense longitudinal collagen bands in the middle and deep subcutaneous regions that increases proportionately with the number of treatments administered. Distortion and disruption of adipocytes were also demonstrated in this study.

Deep mechanical massage has not been shown to have any effect on epidermal thickness or accumulation of mast cell aggregates.

References
1. Adcock D, Paulsen S, Davis S, et al. Analysis of cutaneous and systemic effects of Endermologie in the porcine model. Aesthetic Surg J. 1998;18:414.
2. Adcock D, Paulsen S, Jabour K, et al. Analysis of the effect of deep massage in the porcine model. Plast Reconstr Surg. 2001;108:233.
3. Fodor PB. Endermologie (LPG): does it work? Aesthetic Plast Surg. 1997;21:68.

Which of the following is the primary disadvantage of autologous cartilage grafting?

(A) Immunogenicity
(B) Resorption
(C) Rigidity
(D) Warping

The correct response is Option D.

Autologous cartilage grafts are versatile and can be used for joint reconstruction and soft-tissue fill. The grafts can be carved easily; they retain form with minimal resorption. Because autologous cartilage grafts are biocompatible, there is no risk for rejection.

Types of cartilage used for grafting include hyaline, elastic, and fibrocartilage. Hyaline cartilage functions as a covering for the articular surface of bones. The nasal alae and septum, costal cartilage, and trachea are composed of hyaline cartilage. Elastic cartilage is found in the external ear, epiglottis, and portions of the larynx. Fibrocartilage is firm and comprises intervertebral disks, ligaments, and tendons.

The primary disadvantage of autologous cartilage grafting is the potential for warping. There is an inherent tension within the subperichondrial layer that is released when the cartilage is not carved in a balanced cross section.

References
1. Allcroft RA, Friedman CD, Quatela VC. Cartilage grafts for head and neck augmentation and reconstruction. Otolaryngol Clin North Am. 1994;27:69.
2. Gibson T, Davis WB. The distortion of autologous grafts: its cause and prevention. Br J Plast Surg. 1958;10:257.

Which of the following factors has been shown to stimulate fibroblasts to produce collagen?

(A) Platelet-derived growth factor (PDGF)
(B) Transforming growth factor-beta (TGF-B)
(C) Tumor necrosis factor-alpha (TNF-B)
(D) Vascular endothelial growth factor (VEGF)

The correct response is Option B.

Transforming growth factor-beta (TGF-B) has been shown to stimulate fibroblasts to produce collagen. This factor is one of several signaling molecules and is produced by mesenchymal cells. The epineurial scarring that occurs following injury to peripheral nerves leads to deposition of type I collagen within fibroblasts, subsequently resulting in inhibition of axonal regeneration. Studies have shown that antibody blockage of TGF-B is clinically beneficial in facilitating optimal axonal regeneration after injury.

Platelet-derived growth factor (PDGF), tumor necrosis factor alpha (TNF-B), and vascular endothelial growth factor (VEGF) have not been shown to affect fibroblast deposition of collagen. Instead, these factors produce a variety of end cellular responses.

References
1. Nath RK, Kwon B, Mackinnon SE, et al. Antibody to transforming growth factor beta reduces collagen production in injured peripheral nerve. Plast Reconstr Surg. 1998;102:1100.
2. Sporn MB, Roberts AB, Wakefield LM, et al. Transforming growth factor-beta: biologic function and chemical structure. Science. 1986;233:532.

A 26-year-old man sustains circumferential abrasions and lacerations to the right arm in a roll-over motor vehicle collision. On examination, the arm is covered in dirt and debris. In addition to irrigation of the wound site, which of the following is the most appropriate initial management?

(A) Immediate closure
(B) Operative closure
(C) Immediate split-thickness skin grafting
(D) Daily whirlpool hydrotherapy
(E) Mechanical debridement

The correct response is Option E.

The most appropriate management of this patient is irrigation and mechanical debridement of the wound site. Patients with soft-tissue lacerations covered with debris often have foreign particles embedded within the dermis or subcutaneous tissue. If this material is not removed promptly, a traumatic tattoo will ultimately develop; treatment of this complication is difficult and frequently unsuccessful. Therefore, mechanical devices, such as scrub brushes or pulse irrigation devices, should be used with physical retrieval to ensure that all debris is removed.

Coverage of the extremity with any type of dressing will not address the embedded particulate matter. Hydrotherapy may be useful in removing surface debris but not subcutaneous debris.

References
1. Hall CD, Eisig SB, Hanf CD. The initial management of patients with facial trauma. In: Cohen M, ed. Mastery of Plastic and Reconstructive Surgery. Boston, Mass: Little, Brown & Co; 1994:1060-1068.
2. Hollander JE, Singer AJ, Valentine SM, et al. Risk factors for infection in patients with traumatic lacerations. Acad Emerg Med. 2001;8:716-720.

Administration of which of the following vitamins to a surgical wound has been shown to reverse the adverse effects associated with corticosteroid use?

(A) Vitamin A
(B) Vitamin B6
(C) Vitamin B12
(D) Vitamin C
(E) Vitamin E

The correct response is Option A.

The negative effects on wound healing resulting from corticosteroid use occur secondary to an arrested inflammatory phase. Corticosteroids inhibit wound macrophages and disrupt the mechanisms of fibrogenesis, endogenesis, and wound contraction. Vitamin A restores the monocytic inflammation process that is inhibited by the use of corticosteroids, although its mechanism of action is not fully understood. A dose of 25,000 IU of vitamin A daily for three to five days is recommended.

References
1. Ehrlich P, Tarver H, Hunt PK. The effects of vitamin A and glucocorticoids upon repair and collagen synthesis. Ann Surg. 1973;177:22.
2. Glat PM, Longaker MT. Wound healing. In: Aston SJ, Beasley RW, Thorne CH, eds. Grabb & Smith's Plastic Surgery. 5th ed. Philadelphia, Pa: Lippincott-Raven; 1997:3-12.