LOWER EXTREMITY AND DEGLOVING INJURY

CHAPTER 68 LOWER EXTREMITY AND DEGLOVING INJURY

Peter G. Trafton, Herman P. Houin, Donald D. Trunkey

Injuries of the lower extremity can be devastating (see Mangled Extremities section) and life-threatening or minimal and quickly healed. Advanced Trauma Life Support (ATLS) assessments should be made on all patients. The history, if obtainable, should include the mechanism of injury, initial physical examination by emergency medical services, and any pertinent medical information. Control of exsanguinating hemorrhage and splint immobilization should take priority.

The physical examination should include localization of pain and assessment of pulses, sensation, color, motor function, and angulated or rotational deformities. The entrance and exit of foreign objects that have caused penetration injuries and potentially embedded foreign objects should be noted.

RADIOLOGIC EVALUATION

Thorough evaluation of lower extremity injuries should include anteroposterior and lateral radiographs of the injured area and the joint above and below. Penetrating injuries are best evaluated with entrance and exit site markers. Careful clinical evaluations can minimize needless overuse of angiography (and subsequently its complications and expense); however, if one or more pulses distal to a penetrating injury are absent, the patient needs angiography, computed tomographic arteriography (CTA), or immediate surgery. If pulses are present, ankle brachial indices (ABIs) should be obtained. If the dorsalis pedis and posterior tibialis ABI are 1.0 or greater, the patient can be safely observed for other injuries and discharged with follow-up ABIs taken at 1 week. If the dorsalis pedis or posterior tibialis ABI is less than 1.0 with clinical ischemia, emergency angiography, CTA, or surgery (if distal perfusion is clearly inadequate) should be done if duplex scanning is not available or wounds are extensive, such as shotgun injuries. If distal perfusion is clinically adequate with an ABI less than 1.0, duplex ultrasonography can be done electively. If it is negative or shows only a minor injury (small intimal defect or small pseudoaneurysm), the patient can be observed with follow-up ABIs obtained in 1 week. If duplex scanning reveals a major injury, such as a large intimal defect, large pseudoaneurysm, or intraluminal clot, angiography or exploration should be performed.

FRACTURES

It is now generally accepted that aggressive, appropriate early management of the trauma patient’s musculoskeletal injuries contributes substantially to overall care by reducing morbidity, mortality, and costs. Rehabilitation and ultimate function are also improved. This section is not a “how-to” discussion, but rather provides recommendations for immediate and knowledgeable collaboration with an experienced orthopedic traumatologist. Specific details of management for musculoskeletal injuries are treated only briefly (and thus arbitrarily) here. Several acceptable alternative treatments exist for many fractures. Differences of opinion are thus unavoidable.

Skeletal injuries cannot be managed safely in isolation. The treating physician must always think beyond the broken bone and assess associated soft tissue trauma, the status of the entire injured limb, and the whole patient. Other injuries, age and anticipated activity level, pre-existing musculoskeletal resources, and chances for meaningful participation in a rehabilitation program must also be considered. The choice of management for fractures and joint injuries may depend on whether an injury is isolated or is one of several problems in a patient with multiple injuries. Treatment is also affected by the resources available to the surgeon. In the absence of a well-equipped operating room, effective radiographic monitoring, and an experienced surgical team, modern techniques of internal fixation are likely to fail.

EARLY CARE OF MUSCULOSKELETAL INJURIES

Extremity injuries may be obvious or occult. Initial care of obvious injuries includes control of bleeding with pressure dressings, splinting unstable injuries in an acceptable position, and urgent identification and treatment of arterial occlusion.

Once resuscitation is proceeding satisfactorily, a thorough and systematic search must be made for more occult injuries. All skin surfaces, from digits to trunk, must be inspected for deformity, swelling, ecchymosis, and laceration. Skin abrasions are significant. If they are present in the region of a musculoskeletal injury, any needed operation must be done promptly or delayed until the abrasion heals. Palpate each bone and joint for swelling, deformity, and tenderness. Manually stress each bone to confirm stability. Move each joint to demonstrate normal passive range of motion and absence of abnormal motion (instability). When emergency surgery is a part of the resuscitation or early care of a trauma patient, examination of the extremities should always be completed before terminating the anesthetic. Confirm the presence of peripheral pulses. Obtain radiographs of all abnormal areas.

When the patient is conscious and able to cooperate, active voluntary motion of each joint must be assessed to check motor nerve and myotendinous integrity. Check sensation in the isolated sensory area of each major peripheral nerve. For critically ill patients who are unable to cooperate initially, completion of this evaluation may take several days. Such follow-through is mandatory to avoid missing injuries. Resuscitation of patients with multiple injuries necessarily places diagnosis and treatment of musculoskeletal conditions at a relatively low priority. Many injuries are not initially appreciated. Repeated examinations during the early recovery period are frequently rewarded by the discovery of additional injuries in time for effective treatment.

OPEN FRACTURES

Identification and Classification

Open fractures require special attention to minimize risk of clostridial and pyogenic infections. Treatment is guided by classification of the severity of the injury, primarily according to the extent of soft tissue trauma, and level of contamination (Table 1). It is important to consider the entire soft tissue wound and not just the skin opening. In severe crush injuries, small lacerations may overlie extensively contused or necrotic soft tissue.

Table 1 Classification of Open Fractures

Grade I	Small wounds caused by low-velocity trauma, with minimal contamination and soft tissue damage (e.g., skin laceration by bone end or a low-velocity gunshot wound).
Grade II	Wounds more extensive in length and width, but that have little or no avascular or devitalized soft tissue and minimal contamination.
Grade IIIA	Significant wounds caused by high-energy trauma, often with extensive lacerations and soft tissue flaps, but such that after final debridement, adequate local soft tissue coverage is maintained and delayed primary closure is feasible.
Grade IIIB	Major wounds with considerable devitalized soft tissue, contamination, or both. Bone is exposed in the wound, and extensive periosteal avulsion may be present. Coverage of the soft tissue defect usually requires a local or free microvascular muscle pedicle graft.
Grade IIIC	Open fracture with an associated arterial injury that requires repair.

Identification of an open fracture is the first step of early management. Although they are usually obvious, open fractures occasionally are missed because of an incomplete examination. Posterior surfaces must be checked. Seemingly superficial wounds may communicate with underlying injuries to bones or joints. Neurovascular status, myotendinous function, and the possibility of multiple injuries must be checked. If completely satisfactory examination and treatment of a wound near a fracture cannot be done in the emergency department (ED) assume that the fracture is open and proceed to the operating room (OR) where adequate anesthesia, assistance, hemostasis, and lighting usually confirm suspicions and facilitate treatment.

Once an injured limb has been examined, control of bleeding is achieved with sterile compression dressings, and a splint is applied before transportation to the radiology department or the OR. If a patient arrives with a well-described open fracture already covered, the dressing should optimally be removed only in the OR. Radiographs of injured or suspect areas are essential for evaluating the trauma patient. Unfortunately, the quality of emergency studies varies greatly, and it is risky for the patient to languish, poorly monitored, in the radiology department. The responsible surgeon must be prepared at any moment to conclude that the radiographs already obtained are the best possible and that the patient should proceed to surgery. Chest, pelvis, and cervical spine radiographs have the highest priority. Those of the extremities are necessary for a complete evaluation. Without adequate radiographs, the orthopedic surgeon may not be able to diagnose the extent of the fracture and whether it is an intra-articular injury. Of course, such radiographs may be obtained in the OR once the patient has been stabilized.

Management

It is strongly recommended that each open fracture be cared for in a well-prepared OR, with adequate anesthesia, as soon as is safely possible.

Immediate Wound Care

The basic aspects of surgical wound care have changed little since their description by Desault in the late 18th century. Effective medical adjuncts are more recent. Tetanus prophylaxis is administered immediately. The use of an appropriate IV antibiotic promptly after diagnosis of an open fracture is required. The value of this adjunct to surgical treatment has been shown by several comparative studies. A good requirement is the use 1 g of IV Cefazolin every 8 hours, beginning in the ED and continuing through the 48 hours after injury, regardless of whether the wound is left open. Depending on the source and extent of contamination, aminoglycosides for better Gram-negative coverage and/or penicillin for anaerobic organisms should be added to the initial antibiotic regimen, especially for grade III open fractures. Alternative antibiotics are required for allergic patients.

The properly evaluated patient is brought to the OR as soon as the team and equipment are assembled. Adequate anesthesia is induced, and definitive care of the open fracture is begun simultaneously with or following higher-priority surgical treatment.

Care of the open fracture starts with a thorough reassessment of the injured limb, which takes place under anesthesia. Is salvage warranted or must primary amputation be considered? If amputation seems to be a possibility, an effort to discuss this with the patient and/or the family preoperatively in the ED is optimal. It is also optimal to have another surgeon agree and write a note in the patient’s chart that amputation is the best treatment alternative.

A pneumatic tourniquet is applied, but inflated only if necessary to control bleeding or to assess tissue viability with postischemic hyperemia. In principle, further contamination of the wound of an open fracture should be avoided during cleansing of an injured limb. However, in practice it is hard to scrub the limb adequately while a sterile occlusive dressing is kept over the wound. Most detergents and soaps are injurious to tissue; therefore, the wound itself should be avoided during use of a scrub solution. The scrub is done with the limb lying on a sterile waterproof disposable drape, which is replaced twice during the 10-minute wash. Detergent suds are rinsed, and the skin is dried with sterile towels. At that point, the entire limb, including the wound, is disinfected with iodophor antiseptic solution, and new waterproof sterile drapes are applied.

Irrigation and Debridement

Irrigation and debridement comprise the next step. It is often necessary to enlarge the wound to permit adequate inspection and cleansing. This should be carefully planned to avoid devitalizing skin flaps or interrupting superficial veins that might be essential for blood return. If possible, incisions should avoid contused skin and preserve a healthy flap of tissue to cover the fracture site and any internal fixation device that may be implanted. With sufficient exposure, all foreign matter and any dead or questionable tissue are removed. Nerves, major vessels, and as much bone as possible are not discarded. Grossly contaminated bone surfaces are removed with a rongeur or curet. All joints that have been penetrated are opened and inspected for debris, including osteochondral fragments. It is useful to leave questionably viable skin, which can readily be assessed during the days after injury. Subcutaneous fat, fascia, and injured muscle are aggressively removed if dead or dirty, although it is important not to excessively undermine a viable skin flap. Contractility, consistency, and especially the presence of bleeding from small intrinsic vessels are more helpful than color as indicators of muscle viability.

A pulsatile irrigation system enhances cleansing of injured tissue, although it should be used gently to minimize additional soft tissue injury. Pulsatile lavage pumps may permit use of less than the 10 or more liters of irrigant frequently recommended. Six liters of normal saline or Ringer’s solution for the average grade II open fracture is recommended. Another adjunct, bacitracin solution (50,000 U in 1 liter of normal saline, with two ampules of sodium bicarbonate to alkalinize) as a final antibiotic rinse, can be applied with a bulb syringe.

During debridement, decisions must be made about two other aspects of care for the injured limb: fracture stabilization and wound closure. Complications arising from either of these areas can considerably increase the patient’s period of disability and can jeopardize the eventual result. Avoidance of failure is best achieved by use of techniques with which the surgeon is thoroughly familiar and for which the proper equipment is available. Adequate fracture stabilization is important, and external or internal fixation may reduce the risk for infection and facilitate overall management. Meticulous wound toilet and delayed primary closure are essential if internal fixation is used, and in all grade II and III open wounds.

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Tags: Current Therapy of Trauma and Surgical Critical Care

Jul 7, 2016 | Posted by admin in CRITICAL CARE | Comments Off

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