Management of Soft Tissue Injuries

ByA.M SALEHI

ORAL AND MAXILLOFACIAL SURGEON

INITIAL EXAMINATION

Primary SurveyAirway Maintenance with Cervical Spine ControlBreathingCirculation ManagementDisabilityExposure

Secondary Assessment

Face, Head, and Skull InjuriesNeck InjuriesChest InjuriesOther Potentially Life-Threatening InjuriesAbdominal and Pelvic TraumaSpine and Spinal TraumaExtremities and Fractures

Wounds groups:

Clean Contaminated

Initial Examination

Wound Contamination

Wound Débridement

The species of bacteria present are of less concern in the development of an infection than the total number of bacteria present within the wound. The infectious

inoculum must exceed105 organisms/g

of tissue for gram-positive and gram-negative aerobic bacteria.

Crushing of tissue, the embedding of foreign bodies or soil, and perforation into the oral cavity with contamination of saliva markedly increasethe bacterial count and set the stage for infection.Wounds caused by impact injuries are 100 times more susceptible to infection than wounds caused by shear forces.

Tetanus prophylaxis should be instituted with contaminated wounds.

Prophylactic antibiotics are usually not indicated in clean fresh lacerations of the skin. The probability of contamination increases rapidly and is directly related to the length of time that has elapsed since the initial injury. The contamination of the clean wound is usually via Streptococcus and Staphylococcus spp.

Antibiotics such as penicillin, cephalosporin, and other drugs active against gram-positive organisms arethe drugs of choice for soft tissue injuries.

WOUND DEBRIDEMENT

Cleansing of the clean wound involves washing the skin and removing foreign bodies from the wound. Soap does not harm the skin surface, because the thick cornified layer of epidermis protects the underlying tissue surface, but soap may enter the wound and cause cellular damageand necrosis.

Balanced salt solution (e.g. lactated ringer s solution,normal saline) is appropriate for wound irrigation.

A rule regarding the application of antiseptic is never to put anything in a wound that could not be comfortably tolerated inthe conjunctival sac.

There are at least three mechanisms whereby devitalized soft tissues potentiate infection: 1. As a culture medium promoting bacterial growth. 2. By inhibition of phagocytosis and subsequent bacterial control by leukocytes.3. By the anaerobic environment limitingleukocyte function.

ANATOMY OF THE SKIN

The skin is composed of the surface layer epidermis and the underlying dermal layer. The epidermis is stratified squamous epithelium with five layers (in order from the surface to the dermal layer): the stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum germinativum. The epidermis sends projections into the dermis and irregularities of the dermis interlock with the epidermis; these are termed epidermal pegs and dermal papillae, respectively.

The stratum lucidum is found only on the palms of the hands and soles of the feet.

The stratum corneum, the outermost layer of the epidermis, is formed of keratinized flattened cells that are usually without nuclei. The corneum layer is responsible for the variable thicknesses of skin found on the body.

The dermis is divided into two layers:

1.Superficial papillary layer 2.Deeper reticular layer

The papillary zone is a thin, finely textured zone immediately beneath the epidermal rete ridges

The papillary dermis and epidermis together form a functional unit that provides an important metabolic area for retaining the normal integrity of the skin.

The reticular layer of the dermis is a thick dense mass of collagenous and elastic connective tissue fibers. Reticular fibers, which give the layer its name, are young, finely formed collagen fibers with a narrower diameter than that of mature collagen. Elastic and other collagen fibers in the papillary dermal layer tend to be perpendicularly oriented to the overlying epidermal layer, and the fibers in the reticular layer are mainly oriented tangentially to the epidermal layer.

The dermis also contains a small amount of fat, numerous blood vessels, lymphatics, nerves and sensory nerve endings, hair follicles, sweat and sebaceous glands, andsmooth muscle. The dermis is supported by subcutaneous connective tissue that is thinner in the facial region than in most of the body and is nonexistent in the eyelids.

The muscles of facial expression are in the subcutaneous layer and insert into the reticular layer of the dermis.

LOCAL ANESTHESIA

1% lidocaine solution with 1 : 100,000 epinephrine

0.5% bupivacaine (Marcaine) solution with 1 : 200,000 epinephrine

Alternative local anesthetic for patients who report local allergies is diphenhydramine.

For delivery of a local anesthetic, the following guidelines are recommended:

• Use a needle that is small (25 gauge or smaller).• Insert the needle into the wound margin, as opposed to piercing the intact skin.• Pass the needle through subcutaneous tissue.• Inject slowly.• Insert the needle no more than two thirds of its length to prevent complications associated with needle breakage.

Toxic reactions to local anesthetics are more common than allergic reactions and are usually caused by accidentalintravascular injection or administration of large quantities of the drug.

Patients at the extremes of age are particularly at risk.

The initial signs and symptoms of toxicity caused by local anesthetics are mediated primarily by the central nervous system.

Initially, the patient may experience slurred speech, shivering, muscular twitching in the face and distal extremities, flushing of the skin, dizziness, tinnitus, and disorientation.

Further elevations of local anesthetic blood levels produce seizure activity and later cardiac and respiratorydepression, which can lead to death. The lack of understanding about maximum dosages has led to fatalities in children.

Vasoconstrictors can limit plasma levels of local anesthetics by decreasing the rate of absorption, which reduces the risk of toxic reactions. Additional benefits of vasoconstrictors include increased duration of action of local anesthesia and assisting with hemostasis at the surgical field.

However, the use of vasoconstrictive drugs should be avoided or kept to a minimum in patientsreceiving certain medications such as beta blockers, monoamine oxidase (MAO) inhibitors, and tricyclic antidepressants, or in patients with conditions such as hyperthyroidism, elevated blood pressure (systolic blood pressure greater than 200 mm Hg, diastolic blood pressure greater than 115 mm Hg), and recent cerebrovascular accident or myocardial infarction.

SUTURE MATERIALTo understand the interaction of suture materials with biologic tissue, an appreciation of the wound-healing process is important.

Wound-healing process

Wound healing can be divided into three phases. During the initial lag phase (up to day 5), there is no gain in wound strength and the wound is dependent on sutures and epidermal cellular adhesion to maintain closure. During the fibroblastic phase (days 5 to 15), a rapid increase in wound strength occurs. The maturation phase (day 14 and beyond) is characterized by further connective tissue remodeling.

By the end of the second week, when most skin sutures are removed, only 3% to 7% of the final tensile strength has been achieved.

By the end of the third week, 20% of the tensile strength is attained and, at the end of the first month, 50% is present.

Wounds never regain more than 80% of the strength of intact skin.

Suture material:Absorbable or nonabsorbable Coated or uncoated Natural or synthetic Multifilament (braided)or monofilament

Synthetic, nonabsorbable sutures include:

Dacron (Mersilene, Polydek, Tevdek, Ethibond, and Tycron)

Nylon (Ethilon and Dermalon),

Polypropylene (Prolene and Surgilene).

Natural, nonabsorbable sutures include:

Silk

Cotton

Metals such as stainless steel, tantalum, and titanium

Natural absorbable sutures

Natural absorbable sutures are made of catgut and plain and chromic collagen.

Synthetic absorbable sutures:

Polyglycolic acid (Dexon)

Polyglactic acid (Vicryl)

Polydioxanone (PDS)

Sutures that undergo degradation rapidly and lose their tensile strength within 60 days are termed absorbable.

Those that maintain their tensile strength for longer than 60 days are termed nonabsorbable.

WOUND CLOSUREWith repair of facial wounds, the following guidelines should be followed:1. The injured tissue should be handled gently and minimally débrided to ensure an adequately clean bed.2. Complete hemostasis must be obtained.3. Incisions should be placed to follow tension lines and the natural folds of the skin.

4. The skin margins must be relaxed without tension.5. Fine sutures should be used and removed as early as possible.6. The wound edges should be everted.7. Dead space must be obliterated.8. The tissue should be closed in layers.9. The scar tissue must be allowed to mature before revision procedures.

Wound closure should follow examination, débridement, and preparation of the wound margins.

Key landmarks, such as the eyebrows, mucosal margins of the lip and nose, eyelids, and other anatomic structures, must be aligned and repaired properly.

Wounds in the facial region should be repaired inlayers to provide anatomic alignment and prevent deadSpace.

All deep lacerations must be inspected carefully. Divided muscles should be reapproximated.

When muscle is severed, layered closure is essential; otherwise, the muscle will retract, with a hematoma filling the gap and eventually organizing to form a depressed scar.

Deep layers should be approximated with 3-0 or 4-0 absorbable sutures and the skin should be repaired with 5-0 or 6-0 suture.

Skin sutures are placed in an interrupted fashion or as a continuous subcuticular pull-out suture. Interrupted sutures should be of 5-0 or 6-0 strength, and nylon, polypropylene (Prolene), and polydioxanone (PDS) suture materials are indicated, but occasionally 6-0 chromic gut suture may be used.

Sutures should be placed close to the wound margin and close enough to each other torelieve all wound margin tension.

Excessive numbers of sutures are unnecessary. The needle should enter thetissue at a 90-degree angle to the skin surface, approximately 2 mm from the wound margin.

In lacerations without extensive tissue loss, meticulous attention should be paid to hair and eyebrow alignment, wrinkle continuity, and orientation of muscle movementsto produce unobtrusive scars and restore normal anatomic function.

Skin sutures in the face should be removed 4 to 6 days after placement. Sutures in thin-skinned areas, such as the eyelid, should be removed 3 to 5 days following placement.Alternate sutures can be removed beginningat day 4 and the wound should be supported by adhesive strips.

Suture marks are usually caused by three factors:

(1) skin sutures left in place longer than 7 days,resulting in the epithelialization of the suture track(2) tissue necrosis from sutures that were tied too tightly or became tight from tissue edema

(3) the use of reactive sutures in the skin

Interrupted skin sutures should not be used in patients who are subject to hypertrophic scars.

The continuous subcuticular suture is good for approximation of the skin margins and can be left in place for 3 to 4 weeks, without the formation of suture tracks. Polypropylene or nylon synthetic monofilament materials of 4-0 strength are used for the subcutaneous suture.

Other options

• SURGICAL TAPE• Cyanoacrylate (Histoacryl) • Fibrin tissue adhesives

CLASSIFICATION AND MANAGEMENT OF SOFT TISSUE WOUNDS

• CONTUSIONS• ABRASIONS• LACERATIONS• AVULSION INJURIES

Avulsion

• Underminig and primary closure• Skin graft partial thickness full thickness• Flaps local distant free

Local flaps

• Rotational Flap• Transpositional Flap• Interpolated Flap• Single-Pedicle Advancement Flap• Bipedicle Advancement Flap• V-Y Advancement Flap

Rotational Flap

Double-rotation (O-Z) flaps

Interpolated flap.

The V-Y plasty, or island advancement flap

A bilobed transpositional flap

The classic rhomboid transpositional flap (Limberg flap)

Advancement flap

bilateral advancement flap

Distant flaps

• Pectoralis• Trapezius • Latissimus dorsi• Deltopectoral• And ….

Free flaps

ANIMAL BITES

• Although infections resulting from animal bites are polymicrobial, Pasteurella spp. (P. multocida) are most frequently cultured from dog bite wounds, followed by S. aureus.

• Infections that occur with Pasteurella species are most likely to be seen within 24 hours after the incident whereas, after 24 hours, wounds are more likely to contain Staphylococcus or Streptococcus species

Animal bite management

• Radiographic evaluation• Debridement and irrigation• Primary wound closure or not• Antibiotic therapy• Postexposure rabies prophylaxis

• Puncture types of wounds should not be closed primarily because it is difficult to clean and prepare the wound adequately.

• Bite wounds with extensive crush injury and wounds requiring a considerable amount of débridement are best treated with delayed primary closure.

INJURIES TO STRUCTURES REQUIRING SPECIAL TREATMENT

• LIP• EAR• NOSE• EYEBROW• EYELID• ORAL MUCOSA AND TONGUE• SALIVARY GLANDS AND DUCTS• LACRIMAL APPARATUS• SCALP

Lip

• Mucocutaneous line (gray or white line)• Orbicularis oris muscle

Lip

• In avulsive injuries to the lips, 25% of the upper lip and up to 25% of the lower lip can be lost without resultant functional or aesthetic defects.

Reconstructive flaps used in avulsive lip injuries. A, The Abbe flap. B, The Abbe-Estlander flap. C, The Karapandzic flap.

Ear

• The external ear consist of the pinna, external auditory meatus, and tympanic membrane. The pinna consists of a thin central area of relatively avascular cartilage that depends on the thin overlying layer of skin for its blood supply.

Ear

• The ear has a good blood supply and can maintain large portions of tissue on very small pedicles.

• Conservative débridement and manipulation should be used to maintain as much tissue as possible.

NOSE

• The nose is the most prominent structure on the face and is commonly traumatized.

• Many injuries result in fractures to the bony structure, with or without soft tissue involvement.

NOSE

• Lacerations• Septal hematoma• Nasal bone fx• Nasal bleeding

EYEBROW

• The muscular layer should be closed with fine absorbable sutures to prevent spreading of the tissue and scar formation.

• Special care should also be taken to avoid tight constricting sutures in the area, because hair follicles are sensitive to decreases in blood flow

• If nonvital tissue must be removed, incisions should be made parallel to the hair follicles to injure as few as possible.

• The wound should be inspected and underlying fractures of the frontal sinus or supraorbital rim repaired before closure.

EYELID

• In the treatment of injuries to the eyelid, it is important to restore not only the appearance of the individual but also, and more importantly, the vital function of the structure.

• The major function of the eyelid is to protect the globe and prevent drying of the cornea and adjacent tissue.

• Eyelids aid in removal of tears through the canalicular system.

EYELID

• Lacerations of the eyelids can be divided into two categories, wounds that involve the lid margin and those that do not.

• Lacerations should be closed in layers, restoring the integrity and orientation of the skin, muscle, tarsal, and conjunctival layers.

EYELID

• Lacerations of the upper eyelid must be explored to identify damage to the levator muscle.

• At the point at which the levator attaches to the superior portion of the tarsus, an upper lid fold is normally created.

• If the fold is violated,it should be restored by repair of the muscle-tarsus junction and suture of the subcutaneous layer to the deep structures.

EYELID

• Marginal lacerations must be repaired carefully and accurately to prevent functional and cosmetic defects.

• The most common identifiable structures are the lash line, meibomian gland orifices, and gray line.

EYELID

• Avulsive injuries to the eyelids are treated with fullthickness skin grafts from the postauricular region or the other upper eyelid.

• With avulsive injuries of the lid margins, carefully placed pedicled tissue will usually be maintained because of the excellent blood supply in the region.

EYELID

• Full-thickness eyelid avulsions of less than 25% of the lid length can be approximated primarily as a simple laceration.

• Larger defects require grafts or flaps, such as an Abbe-type rotational flap from the unaffected eyelid.

ORAL MUCOSA AND TONGUE

• Lacerations of the oral mucosa and tongue should be inspected, especially for pieces of teeth or restorations,and débrided as for other wounds.

• The wounds should be thoroughly irrigated with normal saline and sutured loosely.

• Mucosal wounds should be sutured with 3-0 or 4-0 chromic gut suture.

• Deep lacerations should be closed in layers, with chromic gut sutures in the muscle layers to prevent formation of a hematoma.

ORAL MUCOSA AND TONGUE

• The tongue has a rich blood supply and injuries to the tongue or the floor of the mouth may cause serious hemorrhage that could threatens the airway.

• The tongue should be closed in layers, with 4-0 Vicryl (dyed) sutures in the superficial layers.

SALIVARY GLANDS AND DUCTS

• The facial nerve exits the stylomastoid foramen, where it divides into five branches within the substance of the parotid gland.

• The temporal and zygomatic branches run over the zygomatic arch, the buccal branch

courses over the superficial aspect of the masseter muscle along with the parotid duct.

SALIVARY GLANDS AND DUCTS

• The mandibular branch crosses superficially to the facial vessels at the angle of the mandible, and the cervical branch runs down the neck.

• The parotid duct exits the gland anteriorly, runs along the superficial portion of the masseter muscle, and penetrates the buccinator to enter the oral cavity opposite the upper second molar.

SALIVARY GLANDS AND DUCTS

• Treatment of a parotid duct injury depends on the site of the injury.

• If the injury is anterior to the masseter and the distal portion of the duct cannot be located, the duct may be drained directly into the mouth.

• If the injury is over the masseter muscle, the distal and proximal portions may be connected using a stent.

SALIVARY GLANDS AND DUCTS

• If the injury is within the parotid gland, treatment should include closure of the parotid capsule and application of a pressure dressing.

• Lacerations involving the parotid duct frequently damage the buccal branch of the facial nerve because of close approximation of the two structures.

Lacerations to the parotid duct frequently damage the buccal branch of the facial nerve because of the close approximation of the two structures.

SALIVARY GLANDS AND DUCTS

• Facial nerve injuries distal to the parotid gland and medial to the lateral canthus of the eye rarely result in severe disfigurement.

• A rich anastomotic network of the branches of the nerve allows frequent return of function in this area. Repair of the forehead and mandibular branches should be considered because cross innervation in these areas is less predictable.

The parotid duct is typically found along the plane from the tragus of the ear to the middle of the upper lip.

SALIVARY GLANDS AND DUCTS

• Repair of a lacerated submandibular duct is usually unnecessary because a fistula into the mouth usually develops and allows the duct to drain.

• Scarring with obstruction of the duct may eventually require reestablishment of the duct opening.

SALIVARY GLANDS AND DUCTS

• Chronic obstruction or inflammation is usually best treated with removal of the submandibular gland.

LACRIMAL APPARATUS

• Tears produced by the lacrimal gland drain across the surface of the cornea to the medial portion of the eye, where they enter the puncta of the upper and lower lid margins and proceed to the canaliculi in the nasolacrimal apparatus.

• The tears then drain into the inferior meatus of the nose.

LACRIMAL APPARATUS

• Any lacerations of the medial third of the lower lid should immediately raise the suspicion of injury to the inferior canaliculus. Establishing hemostasis of the laceration is mandatory for finding the injury.

• The canaliculus is a fairly large white-walled tube and may be located by placing a lacrimal duct probe through the punctum and into the wound. The canaliculus begins at the punctum and proceeds perpendicular to the eyelid margin for approximately 2 mm and then turns medially and proceeds to the nasolacrimal apparatus.

Anatomy of the nasolacrimal system

SCALP

• The scalp and forehead are portions of the same highly vascularized anatomic unit responsible for protection of the skull.

• They consist of five layers, which can best be remembered by the mnemonic SCALP.

• In order, from the skin to the cranial bone,the layers are skin (S), subcutaneous tissue (C), aponeurosis layer (A), loose subepicranial space (L), and pericranial layer (P).

The layers of the scalp can be remembered by the mnemonic SCALP: Skin, Connective tissue, Aponeurotic layer, Loose connective tissue, and Periosteal or Pericranial layer.

SCALP

• The subcutaneous layer has many large vessels that anastomose freely. Because this layer is so inelastic, the blood vessels minimally contract when severed and tend to bleed easily. Thus, large amounts of blood can quickly be lost.

SCALP

• The pericranium is very vascular and can be easily stripped from the cranium.

• The pericranium will accept a free graft readily because of its excellent vascularity.

• The outer table of the skull will not accept a free graft, so the pericranium is therefore extremely important in any avulsive injury to the scalp.

SCALP

• Avulsed scalp flaps are replaced if the tissue is not badly damaged, and most survive.

• Free graft survival depends on the presence of the pericranium over the skull.

• Closure is easy if the scalp defect is less than 2.5 cm wide. If larger defects are encountered, flaps should be used.

SCALP

• If the pericranial tissue is intact and the cranium has not been fractured, defects in the scalp that cannot closed primarily should be covered with a split-thickness skin graft.

• After stabilization and healing of the defect, the area can be reconstructed by various advancement or rotational flaps to bring similar tissue into the defect, with or without atraumatic tissue expansion

SCALP

• Tissue expansion is an alternative for the closure of wound defects because it provides donor tissue of the same color, texture, and thickness, with minimal scar formation and minor donor site morbidity.

• Tissue expansion involves developing donor tissue without depriving the donor site of tissue.

Double tissue expander application for reconstruction of a scalp burn

SCALP

• If the pericranium has been lost, the exposed cortical cranial bone will not support a skin graft. When bone is exposed in large avulsive injuries of the scalp, primary closure with flap procedures is indicated.

• The flap procedures used with scalp defects include advancement flaps, transpositional flaps, rotation-advancement flaps,and microvascular free scalp flaps.

Hair Apposition Technique • After standard cleaning and débridement, hair

on both sides of a laceration is apposed with a single twist. It is then held into position with tissue adhesives. Severely contaminated wounds, actively bleeding wounds, and patients with hair strands shorter than 3 cm may not be suitable for this technique.

SCALP

• In conclusion, in small superficial scalp wounds in the appropriate clinical situation, the HAT technique may be desirable.