The postoperative management of patients who have undergone orthopedic surgery is unique from most other surgical patients owing to the relatively higher risk of venous thromboembolism (VTE) as well as issues related to mobilization and weight bearing. Bone healing and bone quality are also important considerations in the postoperative setting, particularly after fracture treatment or bone instrumentation. There are several other important complications that occur more commonly in orthopedic patients such as fat embolism and compartment syndrome. The purpose of this chapter is to highlight issues that are more commonly encountered in patients who have undergone an orthopedic procedure.

VTE is a major cause of morbidity and mortality after orthopedic surgery. Many patients who have an orthopedic operation, such as total hip arthroplasty, are of an advanced age and are relatively immobile after surgery, which are known risk factors for VTE. Pelvic and lower extremity fractures are risk factors even in the absence of an operation. Other mitigating factors pertaining to VTE include prior VTE, stroke, myocardial infarction, obesity, congestive heart failure, and hypercoagulable states.

Most deep venous thromboses (DVTs) form in the thigh and calf. Interestingly, less than one-third of patients present with the classic signs of pain, edema, and foot pain. Clinical signs such as calf tenderness are neither sensitive nor specific enough to be used to diagnose DVT. Venous duplex ultrasonography studies are recommended to diagnose DVT. Contrast-enhanced imaging modalities are the most sensitive diagnostic tool, particularly when one is concerned about a proximal DVT. The American Academy of Orthopedic Surgery strongly recommends against routine screening for DVT using duplex ultrasonography and instead recommends using these studies only when there is a high index of suspicion for the presence of a DVT.

DVTs can cause pain and swelling and, in extreme cases, compartment syndrome. However, the most feared complication is that of a pulmonary embolism (PE), which can be fatal.

Early mobilization exercises and mechanical compression devices should begin as soon as possible after total hip and knee replacement. The use of chemical prophylaxis to prevent DVT is controversial in that there is not one preferred pharmacologic agent currently available. Each agent carries its own set of independent risk factors, with postoperative bleeding as one of the most feared risks. There is the known link between postoperative hematoma and subsequent infection. Furthermore, although many pharmacologic agents have been shown to prevent DVT and PE, it is very difficult to show that chemical prophylaxis prevents fatal PE owing to the extreme rarity (0.01%) of the event. Closer examination of available data demonstrates that mechanical compression devices with or without aspirin are noninferior to other forms of chemical anticoagulation after hip and knee replacement. For this reason, pharmacologic agents and/or mechanical compressive devices after total hip and knee replacement are recommended. Mechanical compression should be used alone when patients are at an increased risk for postoperative hemorrhage. In some cases, a filter device may be placed in a large vessel to prevent migration of clots; however, their efficacy is disputed.

VTE prophylaxis in other areas of orthopedics follows similar logic, and the balance between the risks and benefits of chemical anticoagulation must be determined. That is, a patient who has multiple bony fractures after a motor vehicle accident would be at increased risk for VTE; however, if that patient has a cerebral bleed at the same time, then the risks of causing worsening bleeding would have to be closely considered and may outweigh the benefits of using chemical anticoagulation for VTE prophylaxis.

Compartment syndrome occurs when the pressure within a fascial compartment is greater than the perfusion pressure of the compartment, leading to tissue damage. Compartment syndrome is usually associated with bony fractures; however, it can occur in the absence of fracture. In the postoperative setting, one might discover compartment syndrome after a long tourniquet time, poor patient positioning, or if an infusion is mistakenly infiltrated into an extremity. Recognizing compartment syndrome early facilitates prevention of permanent muscle damage. The signs of compartment syndrome include the “six Ps”:

These may be difficult to ascertain, especially when one may not be anticipating the onset of compartment syndrome. Two major risk factors for failure to diagnose compartment syndrome are an obtunded patient and the use of regional anesthesia.

When compartment syndrome is suspected, compartment pressures should be obtained to help provide objective data, which will influence the surgeon’s decision on whether or not to open the fascial compartments. The compartment pressure should be at least 30 mm Hg below the diastolic blood pressure. If the difference in pressures is less than 30 mm Hg, then operative release of the compartment should be considered.

Fat emboli occur in most patients with long bone fractures. Studies have demonstrated that 54% to 96% of trauma patients at autopsy who have suffered long bone fractures will have associated fat emboli. However, the triad of skin, brain, and lung dysfunction, also known as the fat emboli syndrome, only occurs in 1% to 30% of trauma patients. Risk factors for fat embolism include young age and multiple, closed fractures. From a surgical procedure standpoint, reaming of the intramedullary canal in order to place an intramedullary nail or long-stemmed arthroplasty prosthesis is a known risk factor. Typical signs and symptoms may include respiratory and cerebral dysfunction along with a petechial rash. The treatment of fat emboli syndrome is mostly supportive therapy to maintain adequate blood pressure. Corticosteroids are controversial in this setting.