Combined Vascular & Skeletal Trauma

Objectives

1. Understand the clinical manifestations of vascular injury and the diagnostic approaches to confirm or exclude vascular injury in complex extremity trauma.

2. Know the appropriate prioritization of management of vascular injury, skeletal injury, and soft tissue and nerve and tendon injury in complex extremity trauma

3. Be familiar with the criteria for early amputation in complex extremity trauma.

Overview

Complex extremity trauma involving both arterial and skeletal injuries remains challenging. This combination of injuries is rare, comprising only 0.2% of all military and civilian trauma, and only 0.5%-1.7% of all extremity fractures and dislocations. Vascular and trauma surgeons are more likely than orthopedic surgeons to encounter these injuries, as 10%-70% of all extremity arterial injuries are associated with skeletal trauma. In past years, the great majority of complex extremity injuries in the civilian sector have been caused by blunt trauma, although in some recent series penetrating trauma has caused a majority of these injuries. Combat injuries of this type from military series usually are due to high velocity penetrating trauma.

Combined arterial and skeletal extremity trauma imparts a substantially higher risk of limb loss and limb morbidity than do isolated skeletal and arterial injuries. Debakey and Simeone documented this in WWII battle casualties, in which all injured arteries were ligated, reporting amputation in 60% of all combined injuries and 42% in isolated arterial injuries. Although McNamara and coworkers(65) reported a substantial improvement in limb salvage from isolated arterial injuries in the Vietnam War, combined injuries still had a 10-fold greater rate of limb loss(23% vs 2.5%). These authors also documented a higher incidence of failed vascular repair among combined extremity injuries (33%) than among isolated extremity arterial injuries(5%). Romanoff and coworkers reported more than a 3-fold increase in limb loss in combined combat extremity trauma compared to isolated arterial injuries (36% vs 11%) in the hostilities in Israel. This trend has continued into recent years in the civilian sector, even in the most experienced trauma centers, where amputation rates approaching 70% still are reported from combined arterial and skeletal extremity trauma, while less than 5% of limbs currently are lost following isolated arterial or skeletal trauma. Limb loss most commonly is attributed to delay in diagnosis and revascularization in most published series of this unique trauma. Major nerve damage, extensive soft tissue injury which disrupts collaterals and prevents adequate vessel coverage, infection, and compartment syndrome are other reasons for such a high rate of loss of these severely compromised limbs.

Diagnosis

Prompt diagnosis is essential if rapid treatment and optimal limb salvage is to be achieved in these complex extremity injuries. This requires that a high index of suspicion of arterial trauma be applied to every injured extremity by noting whether any hard signs are present (i.e. active hemorrhage, large, expanding or pulsatile hamatoma, bruit or thrill over wound, absent distal pulses, and signs of distal ischemia�the 5 P�s: pain, pallor, paralysis, paresthesias, poikilothermy, or coolness). The presence of hard signs in any blunt or complex extremity trauma requires immediate arteriography due to the relatively low incidence of surgically significant arterial injury in this setting. This is best done by the surgeon as a percutaneous hand-injected study in the trauma center, or on the operating table, to minimize time delay while achieving excellent accuracy.

Popliteal artery injury	Popliteal artery injury
Popliteal artery injuries following leg fractures with hard signs of vascular injury (reduced or absent distal pulses). Both angiograms were done as one-shot percutaneous angios and patients were then operated on immediately.

The absence of hard signs excludes major arterial injury with sufficient accuracy to allow further diagnostic workup to be avoided. Since most complex extremity trauma does not manifest hard signs, avoiding the considerable expense of arteriography in this population has substantial economic advantages.

Superficial femoral artery injury - intimal flap	Resolution at 6 weeks	Popliteal artery injury - nonocclusive	Resolution at 1 week
Blunt supracondylar femur fracture with asympomatic superficial femoral artery nonocclusive intimal flap identified on ER angiography. Non-operatively observed. 6 weeks later, after ORIF, repeat angiogram documents complete resolution of arterial injury.		Undisplaced tibial plateau fracture from gunshot wound with no hard signs. Angiogram shows non-occlusive intimal injury of the popliteal artery. The injury was observed and repeat angiogram one week later documents complete resolution.

This principle holds true even for the especially high-risk injury of posterior knee dislocation, in which setting routine arteriography has been advocated in all cases, due to a substantial risk of popliteal artery disruption and its associated high rate of limb loss. However, those published studies that compare the clinical manifestations of patients with posterior knee dislocation with outcome show no surgically significant arterial injuries in that majority of patients who have no hard signs (Table 1), confirmed by follow-ups of up to 2 years. Again, most cases present without hard signs, allowing major resource savings at no harm to the patient by using only physical findings to exclude arterial injury. Arteriography is indicated only in that minority of patients with knee dislocation presenting with hard signs, to exclude the need for surgery in those 30% of patients who do not have an arterial injury. Immediate surgery without imaging may be undertaken if the clinical picture clearly indicates vascular injury(i.e. absent pulse, cold ischemic foot).

Table 1: Relation of Physical Findings of Vascular Injury to Outcome Following Knee Dislocation

There is no clear role for noninvasive testing in the initial evaluation of complex extremity injuries (Doppler pressures or signals, duplex U/S), due to a paucity of studies of their use in this category of trauma, and uncertainty over its accuracy in the presence of severe tissue disruption and large bulky dressings. Further study is necessary to clarify this. Again, the physical exam quite clearly answers all questions of management in this setting, as absent pulses mandates ruling out vascular injury, and present pulses in the absence of other hard signs reliably excludes vascular injury as well as any imaging modality. Noninvasives add nothing and may lead the examiner astray, as Doppler flow signals may be transmitted by collaterals around a completely occluded or transected vessel, while a pulse can not. Thus, Doppler flow signals DO NOT exclude a vascular injury. The presence or absence of a pulse is all that is necessary to decide on the next step in diagnosis.

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