1 Introduction

Displaced acetabular fractures generally represent high-energy injuries with the potential for multisystem involvement and significant morbidity and mortality. Successful outcomes are predicated on achieving an anatomical reduction of the weight-bearing surface of the acetabulum, concentric reduction of the femoral head, and avoiding complications. In this chapter we address the early complications related to an acetabular fracture and its treatment. Identifying, initiating appropriate treatment, and avoiding these complications can significantly improve long-term patient outcomes ( Table 2.18-1 ).

2 Mortality

The reported prevalence of mortality associated with acetabular fracture surgery ranges from 0–3.6% [1–10]. Letournel and Judet [4] reported 13 (2.3%) deaths in 569 cases. Of these, seven patients were 60 years or older, representing a mortality rate of 5.7% for that group. The most common cause of death was massive pulmonary embolism (4 of 13). The inclusion of two patients with unexplained circulatory collapse, presumably from undiagnosed pulmonary emboli, results in an incidence of thromboembolic events in 6 (50%) of 13. In a series of 100 patients, Helfet and Schmeling [2] reported two fatal pulmonary emboli after induction of anesthesia but before the surgical incision. In both cases, more than 15 days had elapsed since the initial trauma at the time the patients were transferred for management of acetabular fractures.

3 Thromboembolism

Pulmonary emboli remain one of the most significant complications associated with treatment of acetabular fractures. The prevalence in acute acetabular fractures ranges from 1% to as high as 5%. The latter rate is from the series by Helfet and Schmeling [2], and Borer et al [11], which include two deaths after induction of anesthesia. The incidence of deep vein thrombosis (DVT) after an acetabular fracture in obese patients is 2.6 times higher than in patients who are not obese [12].

The incidence of fatal pulmonary embolism is not well described, nor is it accurately related to the incidence of DVT. The incidence of clinically apparent DVT ranges from 2.3–5% in the acetabular fracture literature [1–4, 6–10, 13]. The overall incidence of DVT in polytrauma patients with lower extremity injuries is nearly 60% when vascular testing is used [14, 15]. The actual subclinical incidence of DVT associated with acetabular fractures is likely to be much higher than what has been previously reported.

None of the patients in the series of Helfet and Schmeling [2] had any clinical evidence of DVT. In fact, one of those who sustained a fatal pulmonary embolus had negative venous Doppler and lung perfusion scans 2 days before her death. This seemed to implicate the pelvic and internal iliac vessels as sources of the embolus. Routine methods of screening were inadequate for identification of thrombosis in these vessels. Magnetic resonance imaging (MRI) venography has been shown to be superior to contrast venography in evaluating patients with an acetabular fracture for DVT [16].

There is now consensus that some form of DVT prophylaxis is indicated as part of the treatment of patients with acetabular fractures. However, consensus is lacking as to the method of prophylaxis that is most efficacious, yet confers the lowest perioperative risks. Letournel and Judet [4] have used heparin, warfarin, and, recently, low-molecular-weight heparin. Coagulation studies are monitored daily. Heparin or low-molecular-weight heparin was given for the first 8–12 days, and then the patient was switched to warfarin for a total of 75 days. The DVT prophylaxis was stopped if the patient became ambulatory sooner.

Helfet and Stickney [17] completed a prospective study comparing the use of intermittent compression stockings (ICS) preoperatively with ICS plus subcutaneous heparin preoperatively or warfarin postoperatively. Intermittent compression stockings have an effect on the clotting mechanism other than the mechanical one, or they activate fibrinolytic mechanisms [18]. All patients also underwent noninvasive Doppler vascular evaluation on admission, preoperatively, and postoperatively [19–24]. A total of 114 patients were included in the study. The incidence of DVT in those patients with ICS alone was 16.8% and 1.8% in the anticoagulation group. This study supports the use of ICS with some form of chemical anticoagulation in preventing DVT in patients with lower extremity trauma. However, it does not address the issue of preventing fatal pulmonary embolism.

Fishmann et al [25] conducted a prospective nonrandomized study examining a protocol for DVT and pulmonary embolism prophylaxis in operative management of pelvic and acetabular fractures. There were 197 patients with 203 fractures (148 acetabular, 55 pelvic, 2 bilateral acetabular fractures, and 4 combined acetabular and pelvic fractures). The protocol involved noninvasive screening of the lower extremities preoperatively, vena cava filters, mechanical antithrombotic devices intraoperatively and postoperatively, and chemical prophylaxis with warfarin for 3 weeks following removal of surgical drains. There was a 6% preoperative incidence of DVT and a 3% incidence of postoperative DVT. There was 1 fatal preoperative pulmonary embolism (0.5%) and 2 nonfatal postoperative pulmonary emboli (1%). Although Fishmann et al [25] concluded that their protocol was efficacious; statistical significance between groups was not demonstrated. A systematic review [26] concluded that limited data is available to guide prophylaxis after acetabular fractures and that clinical trials are needed.

We currently recommend that all patients with acetabular fractures be treated with an intermittent compression device plus a form of chemical anticoagulation (eg, low-molecular-weight heparin or warfarin) preoperatively and postoperatively. Note that warfarin is only used postoperatively. The International Normalized Ratio should reach 1.5 times normal.

Screening for thrombosis may be indicated (color Doppler ultrasonography or venography) before surgical reconstruction in some patients; however, screening has not been shown to be beneficial in the prevention of thromboembolic events. Borer et al [11] reported no benefit of DVT screening in preventing pulmonary embolus. Stover et al [27] reported a high false-positive rate with contrast computed tomography (CT) and magnetic resonance venography (MRV) in patients with pelvic and acetabular fractures. Using pelvic venography for confirmation, they reported a 50% false-positive rate with CT venography and a 100% false-positive rate with MRV. They recommended against the use of vena cava filters without confirmation of DVT with venography [27].

Patients with a postoperative pulmonary embolism or DVT (proximal) are treated with full chemical anticoagulation (eg, heparin and warfarin or low-molecular-weight heparin and warfarin). If additional injuries are such that anticoagulation is contraindicated, a vena cava filter is warranted. If the DVT is distal to the trifurcation of the popliteal artery, low-molecular-weight heparin is used, and the patient is followed up with sequential color Doppler ultrasound evaluations. Should proximal propagation be demonstrated, the clot is treated with full chemical anticoagulation. If no propagation is seen, the patient can be treated either with further observation or low-molecular-weight heparin.

The problem treatment groups are those with a preoperative proximal DVT (demonstrated clinically or on vascular testing) or a pulmonary embolism. Many of these patients have additional injuries that may preclude anticoagulation therapy. Performing pelvic surgery on a fully anticoagulated patient would be contraindicated. Preoperative use of vena cava filters has proved most efficacious in this patient population [28].

Selected patients with a preoperative DVT may be fully anticoagulated with heparin, reversed immediately preoperatively, and anticoagulation resumed postoperatively. However, because propagation of the initial clot could occur during surgery, we recommend preoperative use of a vena cava filter for documented proximal DVT in these patients. The decision to use anticoagulation alone in patients at high risk for thrombosis or a vena cava filter in the preoperative treatment of proximal thrombosis must be individualized for each patient.

For the patient who is transferred to hospital several days after injury but DVT prophylaxis has not been initiated before transfer, we recommend screening with a color duplex Doppler ultrasonography or an MRV. We recognize that screening has not been beneficial in preventing thromboembolic events. If findings are negative, the patient is started on routine prophylaxis as previously outlined. The patient is treated with low-molecular-weight heparin and placement of a vena cava filter is considered if positive for a proximal thrombus. Postoperatively, the patient is treated with chemical anticoagulation.

A preoperative DVT distal to the trifurcation of the popliteal artery is treated like the postoperative DVT. Without evidence of propagation of the clot proximally, surgery could proceed as planned. Anticoagulation could be added postoperatively as needed.

The issue of thromboembolism in trauma patients continues to be closely scrutinized in many trauma centers. Further experience with noninvasive testing of the pelvic venous system should make detection of a thrombus easier. Prospective studies are currently evaluating such regimens for their efficacy and safety in trauma patients.

4 Infection

Deep infection following acetabular fracture surgery occurs in 0–10% of patients [1–4, 6–10, 13]. In two large series [4, 6], the prevalence was higher early on when the operative team was less experienced [4, 6] because of an incomplete understanding of the pathological anatomy and to “errors of surgical approach, leading to long surgical procedures, which were followed by several bad infections” [4]. The addition of perioperative antibiotics reduced the infection rate to 1% in Letournel and Judet’ s last 400 cases [4]. Similarly, Matta [29] reported 9% prevalence in his initial series of 43 patients but this decreased to 3% in a subsequent review [30] of 98 patients. Matta [31] later reported an overall 5% prevalence in 262 patients operated on within 3 weeks of injury; 2% were extraarticular and 3% were intraarticular.

Letournel and Judet [4] reported 13 (4.1%) of 314 infections with the Kocher-Langenbeck approach. As they were developing the ilioinguinal approach, the infection rate was 13.2%; however, with a “better understanding of the approach, precautions to preserve the lymphatics, and the use of antibiotics,” the incidence decreased markedly to 8 (5%) of 158. Helfet and Schmeling [2] reported no infections in a series using either the Kocher-Langenbeck or the ilioinguinal approach. Matta [31] reported an infection rate of 4% with the Kocher-Langenbeck approach, 5% with the ilioinguinal and 8% with an extended iliofemoral approach. More recently, Matta [32] reported a 3% prevalence of surgical wound infection after the ilioinguinal approach. Sagi et al [33] reported a 1.8% infection prevalence of the lateral window with the modified Stoppa approach when the lateral window was needed during the exposure. Andersen et al [34] reported an infection prevalence of 1 (6%) in 17 patients treated with the modified Stoppa exposure.

Use of extensile exposures, with their significant soft-tissue dissection and prolonged operative time, would be expected to be associated with a higher infection rate than the single anterior or posterior approach. The extensive subperiosteal dissection involved in the extended exposures potentially creates devascularized bone and soft tissue as well as potential spaces for hematoma formation. Bosse et al [35] illustrated the potential problem with extensile acetabular fracture exposures in patients with a superior gluteal artery injury. During the extended iliofemoral exposure the gluteus medius and gluteus minimus are elevated off the outer table of the ilium, and their insertion is released from the greater trochanter. The only remaining blood supply to the gluteus medius and minimus muscles is from the superior gluteal vessels. Preoperative injury to this vessel and the use of the extended iliofemoral exposure may result in devascularization of the entire abductor muscle mass and subsequent tissue necrosis. This is a devastating complication. Bosse et al [35] recommend preoperative angiography for fractures involving the greater sciatic notch when an extensile exposure is planned.

However, this problem has been demonstrated only in dogs and human anatomical specimens. Letournel and Judet [4] reported no incidences of flap necrosis in their series. Reilly et al [36] used a Doppler to assess flow in the superior gluteal artery during open reduction and internal fixation of 41 acetabular fractures involving the posterior column using the extended iliofemoral exposure. The average displacement of the sciatic notch component of the injury was 2.5 cm. Flow was found in 40 of 41 patients. There was no flap necrosis, and all patients had some abductor function. Routine preoperative angiography for extended exposures is not indicated.

Neither Letournel and Judet [4] nor Matta et al [29, 30] have reported significant infection or wound complication rates with the use of the extended iliofemoral exposure. Reinert et al [9] reported an infection rate of 5% with modification of the extended iliofemoral exposure. Mears and Rubash [7], with the triradiate exposure, had an infection rate of 4%. The significance of preoperative injury to the superior gluteal vessels relative to wound complication rates and infection when an extended exposure is used is still unclear. Owing to the experience gained in the pioneering work of Letournel, Judet, and Matta [4, 29, 30], most subsequent reports using their extended exposures note infection rates of 3% or less.

Other factors that predispose to wound infection are skin necrosis, hematoma formation, and obesity. Patients with a body mass index (BMI) of 40 or higher are five times more likely to develop a postoperative wound infection after surgical repair of an acetabular fracture [12]. The prevalence of skin necrosis and hematoma formation in Letournel and Judet’s series [4] were 1.8% and 7.7%, respectively. Both of these complications can lead to infection. Recognition of the Morel-Lavallée skin injury is essential ( Fig 2.18-1 ). This injury is closed internal degloving that leads to avulsion of the fat from the underlying fascia that leads to an avascular cavity filled with hematoma and liquefied fat. This injury generally lies over the greater trochanter but may be found in the flank or lumbar region. It is a severe injury that devascularizes several soft-tissue planes. Hak et al [37] reviewed 24 cases and presented a treatment protocol. Nearly 50% of the patients had positive cultures obtained from the lesion. They recommended debridement before or during acetabular fracture surgery. Even so, there was still a 13% incidence of infection. Tseng and Tornetta [38] have reported successful treatment of the Morel-Lavallée skin injury with percutaneous debridement, suction drainage, and delayed open reduction procedures. Postoperative hematomas must be viewed as potential sources of infection, and the mainstay of treatment remains perioperative prevention (ie, hemostasis, suction drains, early evacuation, and debridement when they occur).

Related posts:

2.19 Late complications 2.20 Surgical management of delayed acetabular fractures 2.21 Late acetabular reconstruction 2.23 Results of treatment for fractures of the acetabulum 2.22 Malunion and nonunion 1.8.4 The management of the injured pelvic ring: internal fixation of the anterior pelvic injuries—open book (type B1)

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