Managing Degloving & Shearing Injuries

Degloving and shearing (ie, deep degloving)injuries typically occur when an animal ispushed or dragged by a moving vehicle.1-4

The distal limbs are affected more frequentlythan other parts of the body, with the most common site of injury being the medial tarsus/metatarsus.1,2 Various amounts of skin, subcuta-neous tissue, neurovascular supply, muscle, ten-don, ligament, and bone are sheared away byfrictional forces. The structures that remain maybe lacerated or damaged by crushing forces. Inaddition, debris and bacteria are embedded in thewound. Joint instability and joint capsule pene-tration are common, as are concurrent injuries inother parts of the body.1-3

OUTCOMEDespite their often severe appearance, the prognosis for shearing wounds is very good with proper care. In a study by Beardsley andSchrader,1 91% of dogs with healed shearingwounds were clinically normal or had only minorfunctional abnormalities, even dogs that sus-tained extensive tissue loss and orthopedic dam-age. In most cases, primary wound closure is not an option due to loss of soft tissue andinability to convert the contaminated wound to a clean wound during initial treatment. Ownersshould be advised that treatment may requiremultiple surgeries and prolonged open woundmanagement.1,2

PRETREATMENT CONSIDERATIONSPatient stabilization and immediately life-threaten-ing injuries take priority over initial wound man-agement. For example, patients with massive bloodloss or hypovolemia often need fluid or bloodproduct infusion to improve their cardiovascularstatus before sedation or anesthesia can be contem-

plated. To protect wounds while more urgent prob-lems are being managed, they should be coveredwith a sterile bandage as soon as possible.

Wound assessment may require a local anesthetic,sedation, or general anesthesia. When possible, thepatient’s neurologic status should be assessed beforeanesthetic agents or sedatives are administered.

P ro ce d u re s P ro W O U N D M A N A G E M E N T

Bonnie Grambow Campbell, DVM, PhD, Diplomate ACVSWashington State University

Peer Reviewed

WHAT YOU WILL NEED

For All Cases� Sterile surgical instruments and supplies (including gloves)

� Clippers� Sterile water-soluble gel� Surgical skin scrub � Lavage solution in IV fluid bag with administration set and 16- to 22-gauge needle

� IV bag pressure cuff� Analgesics� Sedatives and/or general anesthetic� Moisture-retentive dressings (specific dressing selected is based on the amount of wound exudate and the phaseof wound healing)7

� Bandage material

For Some Cases� Splint, cast, or external skeletal fixator� Orthopedic implants� Doppler ultrasound probe� Stents (eg, suture and IV tubing, red rubber catheter, buttons)

� Stent tighteners (eg, hemoclips, split-shot fishing sinkers)

CONT INUES

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Personstreatingdegloving

and shearing wounds should weargloves, even during clipping andinitial wound evaluation.

P ro ce d u re s P ro C O N T I N U E D

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STEP-BY-STEP MANAGING DEGLOVING & SHEARING INJURIES

STEP 1

Place a generous amount of sterile, water-solublegel in the wound to trap hair clippings. Clipwidely, both for cleanliness and to identifysmaller injuries masked by hair. Also shave flapsof skin overlying the wound. Clean intact skinwith an antiseptic scrub, but do not allow scrubmaterial to seep into the wound.

AUTHORINSIGHT

STEP 2

Lavage the wound to flush out debris,decrease bacterial counts, and rehydratetissues. Effective lavage requires a largevolume of fluid at a pressure of 7 to 8psi. This is most reliably achieved with a16- to 22-gauge needle on a standardintravenous drip set attached to a literbag of fluid pressurized to 300 mm Hg(A and B).5 Larger fluid volumes do notcompensate for inadequate pressure. Useof a stopcock allows sterile control offluid flow.

The use of tap water is acceptable ini-tially for removing surface dirt; however,it should be followed by lavage with asterile, nontoxic solution (not scrub,which harms tissues), such as normalsaline, 0.05% chlorhexidine solution (add 25 mL of 2% chlorhexidine to 975 mL of sterile saline or sterile water),or 0.1% to 1% povidone-iodine solution(add 10 mL of 10% povidone-iodine to990 mL of sterile saline for 0.1% or add 100 mL of 10% povidone-iodine to900 mL of sterile saline for 1%).

Bulbsyringes,squirt bot-

tles, and syringes without nee-dles do not provide adequatelavage pressure.

AUTHORINSIGHT

A

B

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Determine whether each anatomic structure in the area isunharmed, damaged, or missing. Assess tissue viability byevaluating its degree of attachment, color, texture, tempera-ture, bleeding, and sensation. (A) In this shear injury, a flapof skin has been folded back (asterisk) to reveal transectedbranches of the common digital extensor tendon. Diagnosticdifferentials for pale color, cold temperature, and/or lack ofbleeding from cut surfaces include hypovolemia, vasoconstric-tion, or lack of viability; thus, hypovolemia and hypothermiashould be treated before a decision about tissue viability ismade. (Here, the tissues were viable despite the pale colorand lack of bleeding surfaces [B].)

Place a Doppler ultrasound probe on the palmar/plantar sideof the metacarpus/metatarsus to assess distal blood flow.Assess sensation by pricking or pinching tissues with a hypo-dermic needle or hemostat. Lack of sensation may be due totransient neurapraxia or permanent nerve damage. Limbswith extensive neurovascular and/or tissue damage mayrequire amputation; however, this decision should be delayeduntil after treatment of shock and confirmation that suchdamage is permanent.

STEP 3

Place a long monofilamentsuture tag in the peritenonor epineurium of transected

tendons or nerves that will later be anastomosed.The tag allows you to find the end if it retractsinto deeper tissue.

AUTHORINSIGHT

STEP 4

Surgically debride the wound usingaseptic technique. Remove necrotic tis-sue, as it incites inflammation, blocksgranulation, and increases infectionrisk. If the viability of a given piece oftissue is unclear, it may be left in placeto give it time to declare (ie, show forcertain whether it is viable) as long asthe tissue is superficial enough to allowreassessment and resection duringbandage changes.

CONT INUES

A

B

*

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Treat the area as an open wounduntil it is free of contamination, alltissues are clearly viable, and a ten-sion-free closure can be achieved(these conditions rarely exist afterinitial debridement and lavage).Place an appropriate moisture-retentive dressing to support ongoing debridement of the woundby white blood cells. Good dressing choices include calcium alginate (A) for a highly exudative wound,polyurethane foam (B) or hydrocolloid for a wound withmoderate exudate, and hydrogel for a dry wound. Pack or cut the moisture-retentive dressings to fit the woundwithout overlapping surrounding skin, and cover the areawith an absorptive padded bandage (C). Perform seriallavage and surgical debridement until a healthy granula-tion bed forms. The frequency of bandage changes andserial lavage and debridement will depend on the severityof contamination and tissue damage as well as the type ofdressing used.

Negative pressure wound therapy is also a valuable meansof managing exudate and stimulating healing (D). Surgicalforage (making multiple perforations into the medullarycavity with a 0.045- to 0.062-inch Kirschner wire) mayhelp stimulate granulation tissue formation over exposedbone.6

A B

C

DThe advantages7 of using amoisture-retentive dressing overa wet-to-dry dressing include:

� Selective debridement that does not damagehealthy repair tissues

� Accelerated granulation, epithelialization, andcontraction

� Prevention of infection� Increased patient comfort

AUTHORINSIGHT

Learn More On the Web!To learn more about the management of orthopedic injuries associated with shearinginjuries, see our exclusive slide show at cliniciansbrief.com/journal/Orthopedic-Injuries

STEP 5

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See Aids & Resources, back page, for references & suggested reading.

Wound closure can ultimately be achieved by several different means, including the following:� With second intention healing, the wound healson its own but often results in a thin, pink, fragile epithelium (arrows, A). The loss of sig-nificant amounts of tissue can result in a tight,hairless epithelial scar or contracture that limitsjoint movement (B).

� For direct suturing, undermine healthy skin deepto the cutaneous muscle (or, in areas without acutaneous muscle, undermine the skin deep to allsubcutaneous tissue and immediately superficialto the muscle fascia) and close. Avoid causing atourniquet effect from excess tension.

� To stretch the skin, place stents (inthis case made from pairs of redrubber tubing anchored with hori-zontal mattress sutures, C) on bothsides of the wound and tighten seri-ally by adding a hemoclip or split-shot fishing sinker between theknot and tubing (D and E, arrows).Alternatively, loosely place a simplecontinuous or intradermal pattern ofsuture in the skin and tighten dailyby placing a clip or sinker underthe knot at one end.

� Create a subdermal plexus flap oraxial pattern flap if tissue mobilityand wound location allow. Here, adegloving wound on the left lateralthigh of a dog (sustained a monthearlier when the dog was inadver-tently dragged behind a truck) wastreated as an open wound until healthy granula-tion tissue formed. The outlined inguinal skinfold flap (F) was elevated and rotated caudally tocover the degloving wound (G).

� Place a skin graft on a uniformly healthy woundbed. (H) Day of injury. Granulation bed (I) andmeshed, full-thickness skin graft (J) 31 daysafter moist open wound management.

STEP 6

AB

C D E

F

G

I

DorsalCaudal

AUTHOR INSIGHT

Surgical wound closure should be delayed until only healthy tissue is present and tension-free closure

can be achieved.

JH

Dorsal

Caudal