Treatment of vascular injuries in themultiple-ligament-injured knee

TREATMENT OF VASCULAR INJURIES IN THE MULTIPLE-LIGAMENT-INJURED KNEE PETER J. ARMSTRONG, LTC, MC,* and DAVID P. FRANKLIN, MDt

Popliteal vascular injury associated with the multiple-ligamenbinjured knee, including knee dislocation, continues to be an uncommon but morbid injury. The tethering of the popliteal vessels to the femur at Hunter's canal and to the tibia by the soleus muscle allows for significant vascular injury when the supporting ligamentous structure is disrupted. The majority of injuries are related to motor vehicle accidents, including driver and passenger injuries, motor vehicle versus pedestrian injuries (bumper injuries), and motorcycle accidents. The mechanisms of vascular injury, both artery and vein, include stretching that results in intimal injury, contusion, laceration, transection, or avulsion. A high index of suspicion must be maintained in the evaluation of these injuries. Modes of evaluation include physical examination, ankle brachial indices, duplex examination, magnetic resonance imaging, and angiography. Given the potentially devastating consequence of a missed popliteal artery injury, routine arteriography or serial physical examination with duplex examination is recommended for patients with a multiple-ligament-injured knee. Vascular repair to include primary repair, patch angioplasty, or interposition grafting is performed from either a medial or posterior approach. Adjunctive measures include 4-compartment fasciotomy, mannitol administration, and vasodilator therapy. Several controllable factors have been found to improve limb salvage, such as decreased ischemia time, systemic anticoagulation, and 4-compartment fasciotomy. Prompt recognition of vascular injury, prompt restoration of flow, and use of proven adjuncts provides the optimal possibility of limb salvage with popliteal artery injuries associated with the multiple-ligament-injured knee. KEY W O R D S : popliteal vascular injury, knee trauma © 2003 Elsevier Inc. All rights reserved.

Popliteal vascular injury associated with knee trauma continues to result in significant morbidity despite a decreasing amputation rate throughout the last century. Major contributing factors for this continued morbidity include extensive soft-tissue injury, concomitant injuries, and diagnostic delays. As urban trauma in America has increased, the incidence of popliteal arterial and venous injury has increased as well. Popliteal artery injuries account for a disproportionate number of lower extremity amputations relative to their occurrence. Popliteal artery injuries represent 10% of vascular trauma but 65% of amputations. 1 The mechanism of injury effects amputation rates because popliteal injuries from blunt trauma have a higher amputation rate than injuries from penetrating trauma. 2 Historically, popliteal artery injuries associated with knee dislocation have resulted in very high amputation rates (Table 1). Knee dislocations and the multiple-ligament-injured knee continue to be uncommon and probably underdiagnosed entities. The reported individual hospital experience remains small even in large urban centers (Table 2).

From the *Peripheral Vascular Surgery Service, Brooke Army Medical Center~ Fort Sam Houston, TX; and 1Section of Vascular Surgery, Geisinger Medical Center, Danville, PA. Address reprint requests to David P. Franklin, MD, Section of Vascular Surgery, Geisinger Medical Center, 100 N. Academy Drive, Danville, PA 17822-2150. © 2003 Elsevier Inc. All rights reserved. 1060-1872/03/1103-0005530.00/0 doi:10.1053/otsm.2003.35919

The incidence of recognized popliteal artery injury with knee dislocation ranges from 10% to 43%. 1,3-21 Improvements in the expeditious diagnosis and treatment of popliteal artery injury have decreased amputation rates in some series down to zero to 3%,22,2s although delay in therapy continues to result in unacceptable rates of limb lOSS. 24

ANATOMY The popliteal artery is a continuation of the superficial femoral artery as it passes through the tendinous hiatus of the adductor magnus muscle at Hunter's canal. It has several small branches, including the medial and lateral superior geniculate, middle geniculate, and medial and lateral inferior geniculate arteries. The popliteal artery then divides into the tibial arteries as it exits the popliteal fossa. A normal angiogram of the popliteal and proximal tibial vessels obtained in a patient sustaining a knee injury during professional BMX racing is shown in Fig 1. The popliteal vein forms from the confluence of the anterior and posterior tibial veins at the lower border of the popliteus muscle. The vein runs medially and then crosses laterally over the popliteal artery. The popliteal vein becomes the superficial femoral vein as it traverses the tendinous hiatus of the adductor magnus muscle at Hunter's canal. The popliteal vein is frequently duplicated, being present on both the medial and lateral sides of the popliteal artery. The popliteal vessels are tethered to the femur at Hunter's canal and to the tibia by the soleus muscle.

Operative Techniques in Sports Medicine, Vol 11, No 3 (July), 2003: pp 199-207

199

T A B L E 1. Knee Dislocation with Popliteal Artery Occlusions Study

Knee Dislocations

Popliteal Artery Occlusion

Resultant Amputations

Hoovers Kennedy 4 Reckling et al. 5 Shields et al. 6 Meyers et al. 7 Taylor et al. 8 Total

14 22 15 26 18 42 137

9 7 3 10 3 3 35 (25.5%)

8 5 0 5 1 2 21 (60%)

Exposure of the proximal popliteal vessels is initiated by abducting the thigh with flexion at the hip and knee. A 10to 12-cm incision is positioned on the anterior border of the lower sartorius or the inferior edge of the femur if palpable (Fig 2). The sartorius muscle is retracted posteromedially after separating the fascia. The vessels are located by separating the tendinous fibers of the adductor magnus tendon. The popliteal vein is located laterally to the artery at this level. Distal popliteal vessel exposure is also approached by abducting the leg while flexing the knee and hip. A 10- to 12-cm incision is made i cm posterior to the medial border of the tibia. The deep fascia is incised parallel to the skin incision. The medial head of the gastrocnemius is retracted posteromedially, and the vascular bundle is located. The vascular sheath is incised and contains the popliteal vein, popliteal artery, and the tibial nerve. The popliteal artery is located superiolaterally to the vein. The popliteal vein is often paired in this area. Approximately 5 to 6 cm of popliteal artery can be easily isolated down to the origin of the anterior tibial artery. Posterior exposure of the popliteal artery is favored for cases of localized popliteal artery trauma such as intimal flaps or segmental thrombosis. The posterior approach may assist simultaneous revascularization in cases of bilateral popliteal artery injuries. Greater saphenous vein harvest must be completed from the supine position before placing the patient in the prone position. The patient is placed prone with a pillow under both knees. The incision is S shaped and starts medially, with the horizontal component centered in the popliteal skin crease. Skin flaps are developed to allow exposure. The lesser saphenous vein is identified and preserved, if possible, after incising the superficial and deep fascia. The popliteal vein and deeper popliteal artery will be identified after separating the popliteal fat (Fig 3). Careful dissection is required to prevent injury to the tibial nerve.

T A B L E 2. Series of Knee Dislocations City

Knee Dislocations

Number of Years

CincinnatP Los Angeles ~° Jacksonville 11 Phoenix 12 Albuquerque 13 Atlanta TM Shreveport ~5 Jacksonville 16

30 32 38 7 47 19 21 35

10 11 6.5 4 8 4 5 10

200

Fig 1. Normal angiogram performed in a patient with knee dislocation. Patent popliteal and tibial arteries without evidence of spasm or injury are demonstrated.

MECHANISM OF INJURY Vascular injury in the multipleqigament-injured knee is poorly defined in the vascular and orthopedic literature as a separate entity. However, knee dislocation with and without ligament injuries has been well studied in regard to vascular injury. The common causes of knee dislocation are well described, as shown in Table 3. The majority of injuries are related to motor vehicle accidents, including driver and passenger injuries, motor vehicle versus pedestrian injuries (bumper injuries), and motorcycle accidents. Falls from heights are the second most common cause of knee dislocations. However, a series by White et al as of peripheral vascular injuries due to falls described only i of 7 patients with documented knee dislocations (bilateral). Other interesting reported causes of knee dislocations include martial arts injury, 26,27 trampoline injuries, 28 and spontaneous knee dislocation in the morbidly obese. 29 By using a stress machine in a cadaver model, Kennedy 4 investigated the mechanisms of vascular injury with knee dislocation. During anterior knee dislocation, he found that tearing of the posterior capsule occurred at 30 ° of hyperextension, followed by tearing and rupture of the posterior cruciate ligament. He noted that progressive deARMSTRONG AND FRANKLIN

Fig 2. Medial approach to right lower extremity with placement of incisions for proximal and distal popliteal exposure.

grees of hyperextension caused considerable stretching of the popliteal artery, with rupture at an average of 50 ° of hyperextension. The mechanisms of vascular injury, both artery and vein, include stretching that results in intimal injury, contusion, laceration, transection, or avulsion. Trauma in proximity to a vessel may also cause vascular spasm without actual vascular injury occurring. Anterior knee dislocations are more likely to cause intimal injury from excessive stretch, with or without resultant thrombosis. Posterior knee dislocations are more likely to result in complete transection of the vessel. Both types of knee dislocation have consistently been shown to have an increased association with popliteal artery injury. Each accounted for approximately 40% of popliteal injuries in several combined series reported by one author. 17

(

J~')

EVALUATION Patients presenting with knee injuries must be evaluated under a complete trauma protocol. As previously described, the majority of knee dislocations are secondary to motor vehicle accidents and falls. These patients have a significant incidence of concomitant injury. In the series by Wascher et al, 13 a knee dislocation secondary to highenergy trauma was associated with a concomitant lifethreatening injury in 27% of the cases, with a resulting mortality rate of 5%. In the report by Treiman et al, 2° 105 of 220 patients with knee dislocation presented with associated life-threatening injuries, ongoing hemorrhage, or a severely ischemic limb. Patients presenting with knee dislocations should, therefore, be evaluated under complete Advanced Trauma Life Support protocol.

ii

Fig 3. Visualization of the popliteal artery, popliteal vein, and tibial nerve via the posterior approach. The heads of the gastrocnemius have been separated to allow visualization of the anterior tibial artery and tibioperoneal trunk.

i\\\\Ii,!/,¢//:/ TREATMENT OF VASCULAR INJURIES IN THE MULTIPLE-LIGAMENT-INJURED

KNEE

201

T A B L E 3. Causes of Knee Dislocation Study

Knee MVA Falls Dislocation % %

Kennedy 4 22 Roman et aP 30 Dennis et al ~ 38 Wascher et a113 47 Kaufman et a114 19

54.5 60 64.8 74 42

Sisto et al TM

50

Treiman et al 2° Jones et a121

Total

20 115 22 313

64 82 61.4

Sports Other/ Popliteal % Work % Injury

4.5 49 30 7 13,5 8.1 6 18 47 0 0 30 18 0 4.5 9 15.4 10.1

32 3 16.2 2 11 20 18 4.5 13.1

7 10 9 11 6

(32%) (33%) (24%) (23%) (32%)

2 (10%) 27 (23%) 10 (45%) 82 (26.2%)

Trauma patients must be purposefully evaluated for both a dislocated knee and multiple-ligament-injured knee, as well as potential limb ischemia secondary to vascular injury or compartment syndrome. A history of knee dislocation by prehospital personnel or other observers must be taken seriously because up to 50% of knee dislocations may be reduced before hospital presentaLion.4,3°-32 In addition, Varnell et a133 showed that severe knee-ligament disruption and knee dislocation have a similar incidence of popliteal artery injury. If a knee dislocation or multiple-ligament-injured knee is identified, then a brief history focusing on the mechanism of injury, preexisting vascular disease, and vascular disease risk factors should be obtained. The limb should be evaluated for any hard signs of vascular injury to include pulsatile bleeding, expanding hematoma, bruit, or ischemia. The signs of ischemia are described as the 6 P's (pallor, pulselessness, poikolothermia, paresthesias, pain, and paralysis). Soft signs of vascular injury include proximity injury, stable hematoma, peripheral neurologic deficit, and unexplained shock. When hard signs of ischemia are present, patients should be immediately considered for surgical exploration or angiography. Soft signs should prompt consideration for serial physical examination or adjunctive objective tests such as color flow duplex or angiography. Complete pulse examination of the limb, including femoral, popliteal, dorsalis pedis, and posterior tibial arteries, should be performed during the initial evaluation and after knee reduction. Comparison with the contralateral limb may assist in revealing subtle pulse discrepancies. A decrement in pulses after knee reduction is indicative of potential arterial injury. The popliteal fossa should be auscultated for bruits. A complete lower extremity motor and sensory examination is important at initial evaluation and after knee reduction to diagnose associated nerve injury and document baseline function. The calf should be evaluated for compartment syndrome. Multiple studies have shown that a popliteal artery injury may be present despite palpable pulses. Palpable pulses are found in 25% to 55% of patients with popliteal artery injuries. In 7 series with 86 popliteal artery injuries in 269 knee dislocations, palpable pulses were present in 30% of popliteal artery injuries (Table 4). 11'14"16"20"21"33"34The collateral circulation around the knee is abundant in number, although small in caliber. Frequently, the collateral vessels are injured or disrupted secondary to the knee dislocation. Palpable pulses may be present with either intact collateral circulation or nonocclusive popliteal artery injuries. Conversely, diminished or absent pulses may

202

be secondary to arterial spasm without injury of the arterial tree. Patients with obviously ischemic limbs, as shown by the presence of hard signs or life-threatening injuries requiring surgery, are brought immediately to the operating room. Formal angiography in the setting of an obviously ischemic limb has been shown to add a minimum of 2 to 3 hours of additional ischemic time, with little benefit. Arteriography can be performed in the operating room as necessary.10,35 Adjunctive tests for patients with knee dislocation and normal pulses include ankle brachial index (ABI), color flow duplex scan, and angiography. Traditionally, routine formal angiography was advocated for all patients with knee dislocation. 24 An angiogram of an occluded popliteal artery secondary to blunt knee trauma is shown in Fig 4. In contrast, some authors over the last decade have advocated selective angiography based on serial physical examinations. ~1,12,16J9,2° Frykberg et a136 found that routine angiography performed solely for proximity in asymptomatic penetrating extremity wounds yielded a medical cost of $66,000 per identified vascular injury that required surgery. Table 4 lists several series that evaluated the need for routine arteriography. Overall, 32% of patients with knee dislocation had identified popliteal artery injuries, with 30% of these patients maintaining palpable pulses despite the arterial injury. Of these 7 studies, 4 studies had patients with normal pulses that eventually required surgery, 16,2°,2~whereas 3 studies had no surgical requirement for patients with normal pulses, n,14,33 Serial physical examination, ABI, and color flow duplex scan have been evaluated for their ability to detect vascular injuries. Recently, magnetic resonance imaging was evaluated for utility in knee injuries. 37 Magnetic resonance angiography showed 100% agreement with conventional angiography in 6 patients studied by both modalities. Serial physical examination is performed on an inpatient basis for 24 to 72 hours in the presence of an initially normal neurovascular examination. Any change in vascular status prompts either formal arteriography or surgical exploration. A prospective series by Miranda et aP 6 found a 94.3% positive predictive value and 100% negative predictive value with physical examination alone for vascular injury in the dislocated knee. The authors reported 2 patients with an initially normal vascular examination that subsequently developed a pulseless extremity during observation. One of these 2 patients was found to have a popliteal artery occlusion requiring surgical repair. This management protocol is predicated on data showing that

T A B L E 4. Popliteal Artery Injuries with Normal Pulses Series

Dislocations

Knee

Popliteal Artery Injuries

Normal Pulses

Dennis et al. 11 Kaufman et alJ 4 Miranda et alJ 6 Treiman et al. 2o Jones et al. 21 Varnell et al. 33 O'Donnell et al. 34

38 19 35 115 22 30 10 269

9 6 6 33 10 12 10 86 (32%)

5 2 1 9 3 4 3 26

Total

Injuries with (55%) (33%) (17%) (27%) (30%) (25%) (30%) (30%)

ARMSTRONG AND FRANKLIN

gery. 11,13,14,16,19,20,33,39 Of the 3 patients requiring surgery, 2 were operated on for thrombosis of the popliteal artery during the 72-hour observation phase, whereas the other patient presented at 5 weeks with a ruptured popliteal pseudoaneurysm. 16,23,39Separation of popliteal injury secondary to knee dislocations versus injury secondary to fracture about the knee has been difficult in 2 other studies evaluating selective angiography. 40,4l In summary, serial physical examination will miss the approximately 32% of injuries that present with palpable pulses. The majority of these injuries are minor and do not require surgery. However, approximately 6% will require major limb salvage surgery, with some having a delayed presentation. ABI should be obtained in patients with a knee dislocation. The systolic blood pressure of the peroneal, dorsalis pedis, and posterior tibial arteries is determined with a hand-held Doppler and blood-pressure cuff at the ankle. The highest systolic blood pressure at the ankle is then divided by the brachial artery systolic pressure. The ABI is normally greater than 1.0; an ABI less than 0.90 suggests vascular injury. 42 Lynch and Johansen 43 found that an ABI of less than 0.9 had a sensitivity of 87% and a specificity of 97% for arterial injury, with 94% of patients having positive arteriographic findings. With an ABI > 0.9, only 5

Fig 4. A popliteal occlusion secondary to blunt trauma is demonstrated on this angiogram. Reconstitution of the anterior tibial artery is also seen.

nonocclusive minimal vascular injuries such as intimal injuries, arteriovenous fistulas, small false aneurysms, and vessel narrowing will heal without adverse sequelae, because these injuries may not be diagnosed on physical examination alone. A popliteal intimal injury secondary to knee dislocation is shown in Fig 5. In an evaluation of 61 nonocclusive arterial injuries in 50 patients in multiple locations, Stain et al 3s found resolution, improvement, or stabilization in 87% of a subset of 30 patients who had follow-up angiography at 1 to 12 weeks. Furthermore, Stain et al showed that none of these 50 patients required surgery because of delayed arterial thrombosis, hemorrhage, or ischemia. However, 10 patients had persistent arteriovenous fistulas treated at the time of repeat arteriography. Only 8 of the 10 could be treated successfully with endovascular techniques; the remaining 2 refused operative therapy. The evaluation of serial physical examination and nonoperative management for popliteal artery injury secondary to knee dislocation has been reported in 58 patients in the literature. In these 8 series of patients with normal pulse examinations, only 3 of the 58 required sur-

Fig 5. Angiogram showing intimal disruption in the popliteal artery after blunt knee trauma. The anterior tibial artery and tibioperoneal trunk are without injury°

TREATMENT OF VASCULAR INJURIES IN THE MULTIPLE-LIGAMENT-INJURED KNEE

203

minor injuries were found in 79 limbs within 2 weeks of injury by color duplex evaluation. 42 The ABI will not diagnose nonocclusive popliteal artery injuries such as intimal flaps and pseudoaneurysms. The ABI gives more objective data than a simple Doppler signal. The presence of a Doppler signal does not rule out vascular injury. Color flow duplex scan is used extensively in the vascular laboratory. Although operator dependent, it has been shown to safely and accurately diagnose nontraumatic arterial pathology. Duplex has the potential ability to detect minor arterial injuries such as intimal flaps, narrowing, arteriovenous fistula, pseudoaneurysms, and venous injuries. 44 Bynoe et a145 evaluated color flow duplex in 198 patients with 319 potential vascular injuries. These injuries were due to penetrating trauma in 79% and blunt trauma in 21% of patients. They found the sensitivity to be 95%, with a specificity of 99% and an overall accuracy of 98%. Local swelling or hematoma in trauma patients may preclude complete visualization of the vascular system by duplex examination. Color flow duplex has not been directly evaluated for a potential role in the vascular evaluation of the multiple-ligament-injured knee. The most appropriate vascular evaluation for a patient with a knee dislocation without signs of ischemia and palpable pulses continues to be controversial but with a leaning toward selective rather than routine angiography. Routine angiography diagnoses occult vascular injury, but with the majority of these injuries adequately managed nonoperatively. A series by Applebaum et a119 found 3 radiographic abnormalities when performing routine arteriography in 22 patients with knee dislocation, fracture, or soft-tissue injury and palpable pulses. None of these 3 injuries, including 1 popliteal intimal defect, required surgery. However, several authors have reported significant arterial pathology requiring surgical repair that was missed by performing serial physical examinations. 24,35,39 Given the potentially devastating consequence of a missed popliteal artery injury, routine arteriography or serial physical examination with duplex examination is recommended for all patients with knee dislocation. Indications for operation include limb ischemia, ongoing hemorrhage, compartment syndrome, significant angiographic lesion, or significant arterial lesion by duplex examination.

OPERATIVE TREATMENT The fundamentals of operation on popliteal artery injuries include prompt restoration of pulsatile arterial flow, removal of distal thrombus, systemic heparin therapy if not contraindicated, and treatment of compartment syndrome. The controversy of whether to perform vascular repair or orthopedic repair first in combined injuries continues. The appropriate sequence depends on the injury time course and ischemic severity. Prolonged ischemic time or significant ischemic severity mandates prompt restoration of arterial flow before orthopedic repair. The concern for disruption of vascular repair secondary to orthopedic manipulation has not been demonstrated in many large series. Even so, several authors recommend that vascular reconstructions be evaluated by vascular surgery at the 204

end of orthopedic manipulation. Temporary vascular shunts, first introduced by Eger et a146 in 1971, may be used as a bridge to arterial reconstruction. These shunts may be used to allow arterial perfusion during transport or skeletal fixation. The use of temporary shunts is well established, as demonstrated in carotid surgery. Thrombectomy should be performed before shunt placement to prevent distal embolization. Systemic or local heparin therapy should be considered. Johansen et a147reported no shunt complications without the use of systemic heparin therapy in a series with an average shunt dwell time of 3.7 hours. Patient positioning is dependent on the requirement of any coexisting life- or limb-threatening injuries. The popliteal artery reconstruction can be approached medially or posteriorly. The medial approach is preferred, although the posterior approach may be helpful when treating focal as well as bilateral~limited popliteal artery injuries. Both lower extremities should always be prepped to allow harvest of contralateral greater saphenous vein as required. The method of vascular repair depends on the nature of the popliteal artery injury. Choices include lateral repair, end-to-end repair, intimal repair with vein patch, or interposition grafting. The majority of popliteal artery injuries secondary to knee dislocation require an interposition vein graft secondary to the extent of arterial injury. The popliteal artery must be debrided to normal-appearing artery before anastamosis. End-to-end repair may require extensive mobilization of the popliteal artery with sacrifice of collateral vessels to ensure a tension-free repair. Interposition grafting is most commonly performed with greater saphenous vein from the contralateral limb. Prosthetic grafts, including polytetrafluoroethylene (PTFE) and Dacron, have been evaluated for these repairs and have a decreased patency rate. 48 The need for venous repair in association with popliteal artery injuries continues to be controversial. Treatment options include ligation, lateral repair, and interposition vein grafting. An early report of a civilian experience with major venous injuries, including 4 popliteal venous repairs, was published in 1960.49 The need for venous repair in conjunction with popliteal artery repair was first evaluated in Vietnam by Rich et al. 5° Ligation of a popliteal venous injury in conjunction with a popliteal artery repair resulted in venous hypertension and limb loss in several cases reported from the Vietnam experience.51 In an experimental canine hindlimb model, Hobson et al, 52 showed that venous ligation caused a 50% to 75% reduction in femoral arterial flow and an increase in femoral venous pressure. The fate of venous repairs was evaluated by Meyer et a153 in 36 patients. They found that 40% had thrombosed by postoperative day 7, and that lateral repair had a statistically significant increased patency rate compared with interposition vein grafting. Noninvasive evaluation to include physical examination and impedance plethysmography was not found to provide an accurate assessment of venous patency in this setting. A retrospective analysis of 115 civilian venous injuries found an increased incidence of lower extremity edema after vein ligation compared with repair. 54 Concern for an increased incidence of pulmonary embolus and thromboARMSTRONG AND FRANKLIN

phlebitis after venous repair has not been supported by the literature. 53,55 Civilian series of vein ligation versus repair have not shown a statistically significant difference in amputation rates. 56,57 General agreement currently can be reached on the appropriateness of popliteal venous repair by lateral suture in stable patients. The ipsilateral saphenous vein should never be harvested for arterial or venous repair because it maintains superficial venous drainage of the injured leg. Before venous repair, all proximal and distal thrombi must be removed. The role of interposition grafting in popliteal venous repair continues to be controversial. Endovascular therapies role in the treatment of traumatic popliteal artery injuries is presently undefined. As shown in Fig 6, a popliteal stent can be placed in the popliteal artery for an intimal injury secondary to knee dislocation. The artery is patent, as shown on duplex examination 3 months after placement, although the longterm patency of such interventions remains unknown at this time (Fig 7). The role for primary amputation in knee dislocations is usually not dependent on vascular injury but rather on the extent of neurologic, soft tissue, and osseous damage. Absolute indications in the literature include complete tibial nerve disruption in the adult and warm ischemia time greater than 6 hours in extensive crush injuries, s8

ADJUNCTIVE MEASURES Fig 6. Angiogram showing popliteal artery inUmal injury treated by percutaneous stent placement. The completion angiogram demonstrates an excellent technical result.

Limb salvage after popliteal artery injuries may be affected by small-vessel thrombosis distal to the injury. The use of systemic heparin or local thrombolytics has been evalu-

Fig 7. Duplex scan at 3 months after stent placement reveals a patent popliteal artery without stenosis. The stent is clearly visible on the duplex examination.

TREATMENT OF VASCULAR INJURIES IN THE MULTIPLE-LIGAMENT-INJURED KNEE

205

ated to c o m b a t distal small-vessel thrombosis. Melton et a159 studied factors that m a y i m p a c t limb salvage after popliteal artery t r a u m a . T h e y f o u n d that severity of limb injury w a s highly predictive of a m p u t a t i o n . The only controllable factor f o u n d to affect a m p u t a t i o n rate w a s the use of systemic h e p a r i n or local urokinase. D a u g h e r t y et al 1 f o u n d that 75% of patients u n d e r g o i n g systemic anticoagulation v e r s u s 43% of patients not u n d e r g o i n g anticoagulation h a d a satisfactory result after popliteal artery repair. W a g n e r et a157 also f o u n d a statistically significant decrease in a m p u t a t i o n rate w i t h systemic heparinization. Systemic anticoagulation w i t h h e p a r i n is r e c o m m e n d e d for all patients w i t h popliteal artery injury in the absence of contraindications. I n t r a o p e r a t i v e local t h r o m b o l y t i c t h e r a p y m a y be c o n s i d e r e d in patients w i t h distal t h r o m bosis in the absence of contraindications. The use of m a n n i t o l to limit r e p e r f u s i o n s y n d r o m e after popliteal artery repair is s u p p o r t e d b y e x p e r i m e n t a l a n d clinical evaluation. Buchbinder et al 6° studied the effects of m a n n i t o l in the canine h i n d l i m b model. Mannitol a d m i n istration w a s f o u n d to decrease tissue e d e m a , vascular resistance, a n d the low flow state. These investigators then utilized m a n n i t o l in 15 consecutive patients w i t h l o w e r e x t r e m i t y ischemia a n d n o n e d e v e l o p e d graft t h r o m b o s i s or c o m p a r t m e n t s y n d r o m e . Mannitol is k n o w n to be an o x y g e n free-radical s c a v e n g e r a n d osmotic diuretic. R e p e r f u s i o n injury in m a n y organs is m e d i a t e d b y o x y g e n free-radical p r o d u c t i o n , w h i c h is k n o w n to increase vascular permeability. 61,62 Routine use of m a n n i t o l is recomm e n d e d , b a s e d on safety a n d r e p o r t e d efficacy, s7 M u s c u l a r vessels m a y s p a s m after injury a n d account for d e c r e a s e d pulses on physical examination. S p a s m can clearly be r e c o g n i z e d b y its a n g i o g r a p h i c findings. Decreased or absent pulses m u s t n e v e r be attributed to s p a s m w i t h o u t objective a n g i o g r a p h i c evidence. If s p a s m is n o t e d on a n g i o g r a p h y , then intra-arterial infusion of v a s o d i l a t o r s m a y be p e r f o r m e d . Tolazoline has b e e n m o s t effective in i m p r o v i n g distal flow s e c o n d a r y to s p a s m after fracture reduction. 63 C o m p a r t m e n t s y n d r o m e m a y be responsible for an a b n o r m a l pulse e x a m i n a t i o n in the absence of a n y arterial injury, a n d m u s t be ruled out as a cause of vessel n a r r o w i n g before v a s o d i l a t o r therapy. F o u r - c o m p a r t m e n t f a s c i o t o m y for the t r e a t m e n t of comp a r t m e n t s y n d r o m e is required in 50% to 80% of patients w i t h popliteal artery injury. 2,22,56,57,64,65 Fainzilber et a164 f o u n d f a s c i o t o m y to significantly correlate w i t h limb salvage. T h e y also f o u n d a zero a m p u t a tion rate in 10 patients w i t h popliteal vein ligation w h e n c o m b i n e d w i t h fasciotomy. F a s c i o t o m y should be perf o r m e d before vascular repair if c o m p a r t m e n t s y n d r o m e is s u s p e c t e d or confirmed. Absolute indications for fasc i o t o m y include c o n f i r m e d c o m p a r t m e n t s y n d r o m e b y c o m p a r t m e n t p r e s s u r e m e a s u r e m e n t or c o m b i n e d arterial a n d v e n o u s repair. F a s c i o t o m y s h o u l d also be strongly c o n s i d e r e d in cases of p r o l o n g e d shock, p r o l o n g e d ischemia, or e x t r e m i t y swelling.

CONCLUSIONS Vascular injury associated w i t h knee injuries continues to account for significant morbidity. As recently as 1995, a 47% a m p u t a t i o n rate for popliteal artery injuries in blunt

206

t r a u m a still existed. 64 Several controllable factors h a v e b e e n f o u n d to i m p r o v e limb salvage, including decreased ischemia time, systemic anticoagulation, a n d 4 - c o m p a r t m e n t fasciotomy. The decrease in a m p u t a t i o n rates seen in p e n e t r a t i n g popliteal artery injuries continues to elude patients w i t h b l u n t popliteal artery injury. A h i g h index of suspicion of vascular injury m u s t a l w a y s be present. P r o m p t recognition of vascular injury, p r o m p t restoration of flow, a n d use of p r o v e n adjuncts p r o v i d e s the o p t i m a l possibility of limb salvage w i t h popliteal artery injuries.

REFERENCES 1. Daugherty ME, Sachatello CR, Ernst CB: Improved treatment of popliteal artery injuries. Arch Surg 113:1317-1321, 1978 2. Reynolds R, McDowell HA, Diethelm AG: The surgical treatment of blunt and penetrating injuries of the popliteal artery. Am Surg 49: 405-410, 1983 3. Hoover NW: Injuries of the popliteal artery associated with fractures and dislocations. Surg Clin North Am 41:1099-1112, 1961 4. Kennedy JC: Complete dislocation of the knee joint. J Bone Joint Surg 45-A:889-904, 1963 5. Reckling FW, Peltier LF: Acute knee dislocations and their complications. J Trauma 9:181-191, 1969 6. Shields L, Mohinder M, Cave EF: Complete dislocation of the knee: experience at the Massachusetts General Hospital. J Trauma 9:192195, 1969 7. Meyers MH, Harvey JP: Traumatic dislocation of the knee joint: a study of 18 cases. J Bone Joint Surg 53A:16-29, 1971 8. Taylor AR, Arden GP, Rainey HA: Traumatic dislocation of the knee: a report of 43 cases with special reference to conservative treatment. J Bone Joint Surg 54B:96-102, 1972 9. Roman PD, Hopson CN, Zeruai EJ: Traumatic dislocation of the knee: a report of 30 cases and literature review. Orthop Rev 12:917-924, 1987 10. Bryan T, Merritt P, Hack B: Popliteal arterial injuries associated with fractures or dislocations about the knee as a result of blunt trauma. Orthop Rev 20:525-530, 1991 11. Dennis JW, Jagger C, Frykberg ER, et al: Reassessing the role of arteriograms in the management of posterior knee dislocations. J Trauma 35:692-697, 1993 12. Bunt TJ, Malone JM, Karpman R, et al: Frequency of vascular injury with blunt trauma-induced extremity injury. Am J Surg 160:226-228, 1990 13. Wascher DC, Dvirnak PC, DeCoster TA: Knee dislocation: initial assessment and implications for treatment. J Orthop Trauma 11:525529, 1997 14. Kaufman SL, Martin LG: Arterial injuries associated with complete dislocation of the knee. Radiology 184:153-155, 1992 15. Martinez D, Sweatman K, Thompson EC: Popliteal artery injury associated with knee dislocations. Am Surg 67:165-167, 2001 16. Miranda F, Dennis JW, Veldenz HC, et al: Confirmation of the safety and accuracy of physical examination in the evaluation of knee dislocation for injury of the popliteal artery: a prospective study. Trauma 52:247-252, 2002 17. Green NE, Allen BL: Vascular injuries associated with dislocations of the knee. J Bone Joint Surg 59:236-241, 1977 18. Sisto DJ, Warren RF: Complete knee dislocation: a follow-up study of operative treatment. Clin Orthop 198:94-101, 1985 19. Applebaum R, Yellin AE, Pentecost M, et al: Role of routine arteriography in blunt lower-extremity trauma. Am J Surg 160:221-225, 1990 20. Treiman GS, Yellin AE, Weaver FA, et al: Examination of the patient with a knee dislocation: the case for selective arteriography. Arch Surg 127:1056-1063, 1992 21. Jones RE, Smith EC, Bone GE: Vascular and orthopedic complications of knee dislocation. SGO 149:554-558, 1979 22. Lim LT, Michuda MS, Flanigan DP, et ah Popliteal artery trauma: 31 consecutive cases without amputation. Arch Surg 115:1307-1313, 1980 23. Bishara RA, Pasch AR, Lim LT, et al: Improved results in the treatment of civilian vascular injuries associated with fractures and dislocations. J Vasc Surg 3:707-711, 1986 ARMSTRONG AND FRANKLIN

24. Gupta R, Quinn P, Rao S, et al: Popliteal artery trauma. A critical appraisal of an uncommon injury. Injury 32:357-361, 2001 25. White RA, Scher LA, Samson RH, et al: Peripheral vascular injuries associated with falls from heights. J Trauma 27:411-414, 1987 26. Viswanath YKS, Rogers IM: A non-contact complete knee dislocation with popliteal artery disruption, a rare martial arts injury. Postgrad Med J 75:552-553, 1999 27. Perron AD, Brady WJ, Sing RF: Orthopedic pitfalls in the ED: vascular injury associated with knee dislocation. Am J Emerg Med 19:583-588, 2000 28. Kwolek CJ, Sundaram S, Schwarcz TH, et al: Popliteal artery thrombosis associated with trampouline injuries and anterior knee dislocations in children. Am Surgeon 64:1183-1187, 1998 29. Hagino RT, DeCaprio JD, Valentine RJ, et ah Spontaneous popliteal vascular injury in the morbidly obese, J Vasc Surg 28:458-463, 1998 30. Lefrak EA: Knee dislocation. Arch Surg 111:1021-1024, 1976 31. O'Donoghue DH: Dislocation of the knee. Orthop Rev 4:19-29, 1975 32. Wascher DC: High-velocity knee dislocation with vascular injury: treatment principles, Clin Sports Med 19:457-77, 2000 33, Varnell RiM, CoIdwell DM, Sangeorzan BJ, et al: Arterial injury complicating knee disruption. Am J Surg 55:699-704, 1989 34. O'Dormell TF, Brewster DC, Darling RC, et al: Arterial injuries associated with fractures and/or dislocations of the knee. J Trauma 17:775-782, 1977 35. Shah DM, Naraynsingh V, Leather RP, et ah Advances in the management of acute popliteal vascular blunt injuries. J Trauma 25:793797, 1985 36. Frykberg ER, Crump JM, Vines FS, et al: A reassessment of the role of arteriography in penetrating proximity extremity trauma: a prospective study. J Trauma 29:1041-1052, 1989 37. Potter HG, Weinstein M, Allen AA, et al: Magnetic resonance imaging of the multiple-ligament injured knee. J Ortho Trauma 16:330339, 2002 38. Stain SC, Yellin AE, Weaver FA, et al: Selective management of nonocclusive arterial injuries. Arch Surg 124:1136-1141, 1989 39. Gable DR, Allen JW, Richardson JD: Blunt popliteal artery injury: is physical examination alone nough for evaluation? J Trauma 43:541544, 1997 40. Abou-Sayed H, Berger DL: Blunt lower-extremity trauma and popliteal artery injuries: revisiting the case for selective angiography. Arch Surg 137:585-589, 2002 41. Harrell DJ, Spain DA, Bergamini TM, et al: Blunt popliteal artery trauma: a challenging injury. Am Surg 63:228-232, 1997 42. Johansen K, Lynch K, Paun M, et al: Non-invasive vascular tests reliably exclude occult arterial trauma in injured extremities. J Trauma 31:515-522, 1991 43. Lynch K, Johansen K: Can Doppler pressure measurement replace "exclusion" arteriography in the diagnosis of occult extremity arterial trauma? Ann Surg 214:737-741, 1991 44. Fry WR, Smith S, Sayers DV, et ah The success of duplex ultrasonographic scamping in diagnosis of extremity vascular proximity trauma. Arch Surg 128:1368q372, 1993

45. Bynoe RP, Miles WS, Bell RM, et al: Noninvasive diagnosis of vascular trauma by duplex ultrasonography. J Vasc Surg 14:346-352, 1991 46. Eger M, Goldman L, Goldstein A, et al: The use of a temporary shunt in the management of arterial vascular injuries. Surg Gynecol Obset 132:67-70, 1971 47. Johansen K, Bandyk D, Thiele B, et ah Temporary intraluminat shunts: resolution of a management dilemma in complex vascular injuries. J Trauma 22:395-402, 1982 48. Feliciano DV, Bitondo CG, Mattox KL, et al: Civilian trauma in the 1980's: a 1 year experience with 456 vascular and cardiac injuries. Arm Surg 199:717-724, 1984 49. Gaspar MR, Treiman RL: The management of injuries to major veins. Am J Surg 100:171-175, 1960 50. Rich NM, Baugh JH, Hughes CW: Popliteal artery injuries in Vietnam. Am J Surg 118:531-534, 1969 51. Rich NM, Jarstfer BS, Greer RM: Popliteal artery repair failure: causes and possible prevention. J Cardiovasc Surg 15:340-351, 1974 52. Hobson RW, Howard EW, Wrigh CB, et al: Hemodynamics of canine femoral venous ligation: significance in combined arterial and venous injuries. Surgery 74:824-829, 1973 53. Meyer J, Walsh J, Schuler J, et ah The early fate of venous repair after civilian vascular trauma. Ann Surg 206:458-464, 1987 54. Agarwal N, Shah PM, Clauss RH, et at: Experience with 115 civilian venous injuries. J Trauma 22:827-832, 1982 55. Rich NM, Collins GJ, Andersen CA, et al: Autogenous venous interposition grafts in repair of major venous injuries. J Trauma 17:512520, 1977 56. Peck JJ, Eastman AB, Bergan JJ, et at: Popliteal vascular trauma: a con~a~nunity experience. Arch Surg 125:1339-1344, 1990 57. Wagner WH, Calkins ER, Yellin AE, et ah Blunt popliteal artery trauma: one hundred consecutive injuries. J Vasc Surg 7:736-743,1988 58. Lunge RH, Bach AW, Habsen ST Jr, et al: Open fibial fractures with associated vascular injuries: prognosis for limb salvage. J Trauma 25:203-208, 1985 59. Melton SM, Croce MA, Patton IH, et al: Popliteal artery trauma: systemic anticoagulation and intraoperative thrombolysis improves limb salvage. Ann Surg 225:518-529, 1997 60. Buchbinder D, Karmody AM, Leather RP, et ah Hypertonic mannitoh its use in the prevention of revascularization syndrome after acute arterial ischemia. Arch Surg 116:414-421, 1981 61. McCord JM: Oxygen-derived free radicals in postischemic tissue injury. N Engl J Med 312:159-163, 1985 62. Bulkley GB: The role of oxygen free radicals in human disease processes. Surgery 94:407-411, 1983 63. Dickerman RM, Gewertz BL, Foley DW, et al: Selective intra-arterial tolazoline infusion in peripheral arterial trauma. Surgery 81:605-609, 1977 64. Fainzilber G, Roy-Shapira A, Wall M, et al: Predictors of amputation for popliteal artery injuries. Am J Surg 170:568-571, 1995 65. McCabe CJ, Ferguson CM, Ottinger LW: Improved limb salvage in popliteal artery injuries. J Trauma 23:982-985, 1983

TREATMENT OF VASCULAR INJURIES IN THE MULTIPLE-LIGAMENT-INJURED KNEE

207